[PATCH] AFS filesystem (1/2)

This adds RxRPC support to Linux for use by the AFS filesystem

include/rxrpc/call.h

+/* call.h: Rx call record
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_CALL_H
+#define _LINUX_RXRPC_CALL_H
+
+#include <rxrpc/types.h>
+#include <rxrpc/rxrpc.h>
+#include <rxrpc/packet.h>
+#include <linux/timer.h>
+
+#define RXRPC_CALL_ACK_WINDOW_SIZE	16
+
+extern unsigned rxrpc_call_rcv_timeout;		/* receive activity timeout (secs) */
+extern unsigned rxrpc_call_acks_timeout;	/* pending ACK (retransmit) timeout (secs) */
+extern unsigned rxrpc_call_dfr_ack_timeout;	/* deferred ACK timeout (secs) */
+extern unsigned short rxrpc_call_max_resend;		/* maximum consecutive resend count */
+
+/* application call state
+ * - only state 0 and ffff are reserved, the state is set to 1 after an opid is received
+ */
+enum rxrpc_app_cstate {
+	RXRPC_CSTATE_COMPLETE		= 0,	/* operation complete */
+	RXRPC_CSTATE_ERROR,			/* operation ICMP error or aborted */
+	RXRPC_CSTATE_SRVR_RCV_OPID,		/* [SERVER] receiving operation ID */
+	RXRPC_CSTATE_SRVR_RCV_ARGS,		/* [SERVER] receiving operation data */
+	RXRPC_CSTATE_SRVR_GOT_ARGS,		/* [SERVER] completely received operation data */
+	RXRPC_CSTATE_SRVR_SND_REPLY,		/* [SERVER] sending operation reply */
+	RXRPC_CSTATE_SRVR_RCV_FINAL_ACK,	/* [SERVER] receiving final ACK */
+	RXRPC_CSTATE_CLNT_SND_ARGS,		/* [CLIENT] sending operation args */
+	RXRPC_CSTATE_CLNT_RCV_REPLY,		/* [CLIENT] receiving operation reply */
+	RXRPC_CSTATE_CLNT_GOT_REPLY,		/* [CLIENT] completely received operation reply */
+} __attribute__((packed));
+
+extern const char *rxrpc_call_states[];
+
+enum rxrpc_app_estate {
+	RXRPC_ESTATE_NO_ERROR		= 0,	/* no error */
+	RXRPC_ESTATE_LOCAL_ABORT,		/* aborted locally by application layer */
+	RXRPC_ESTATE_PEER_ABORT,		/* aborted remotely by peer */
+	RXRPC_ESTATE_LOCAL_ERROR,		/* local ICMP network error */
+	RXRPC_ESTATE_REMOTE_ERROR,		/* remote ICMP network error */
+} __attribute__((packed));
+
+extern const char *rxrpc_call_error_states[];
+
+/*****************************************************************************/
+/*
+ * Rx call record and application scratch buffer
+ * - the call record occupies the bottom of a complete page
+ * - the application scratch buffer occupies the rest
+ */
+struct rxrpc_call
+{
+	atomic_t		usage;
+	struct rxrpc_connection	*conn;		/* connection upon which active */
+	spinlock_t		lock;		/* access lock */
+	struct module		*owner;		/* owner module */
+	wait_queue_head_t	waitq;		/* wait queue for events to happen */
+	struct list_head	link;		/* general internal list link */
+	struct list_head	call_link;	/* master call list link */
+	u32			chan_ix;	/* connection channel index (net order) */
+	u32			call_id;	/* call ID on connection (net order) */
+	unsigned long		cjif;		/* jiffies at call creation */
+	unsigned long		flags;		/* control flags */
+#define RXRPC_CALL_ACKS_TIMO	0x00000001	/* ACKS timeout reached */
+#define RXRPC_CALL_ACKR_TIMO	0x00000002	/* ACKR timeout reached */
+#define RXRPC_CALL_RCV_TIMO	0x00000004	/* RCV timeout reached */
+#define RXRPC_CALL_RCV_PKT	0x00000008	/* received packet */
+
+	/* transmission */
+	rxrpc_seq_t		snd_seq_count;	/* outgoing packet sequence number counter */
+	struct rxrpc_message	*snd_nextmsg;	/* next message being constructed for sending */
+	struct rxrpc_message	*snd_ping;	/* last ping message sent */
+	unsigned short		snd_resend_cnt;	/* count of resends since last ACK */
+
+	/* transmission ACK tracking */
+	struct list_head	acks_pendq;	/* messages pending ACK (ordered by seq) */
+	unsigned		acks_pend_cnt;	/* number of un-ACK'd packets */
+	rxrpc_seq_t		acks_dftv_seq;	/* highest definitively ACK'd msg seq */
+	struct timer_list	acks_timeout;	/* timeout on expected ACK */
+
+	/* reception */
+	struct list_head	rcv_receiveq;	/* messages pending reception (ordered by seq) */
+	struct list_head	rcv_krxiodq_lk;	/* krxiod queue for new inbound packets */
+	struct timer_list	rcv_timeout;	/* call receive activity timeout */
+
+	/* reception ACK'ing */
+	rxrpc_seq_t		ackr_win_bot;	/* bottom of ACK window */
+	rxrpc_seq_t		ackr_win_top;	/* top of ACK window */
+	rxrpc_seq_t		ackr_high_seq;	/* highest seqno yet received */
+	rxrpc_seq_t		ackr_prev_seq;	/* previous seqno received */
+	unsigned		ackr_pend_cnt;	/* number of pending ACKs */
+	struct timer_list	ackr_dfr_timo;	/* timeout on deferred ACK */
+	char			ackr_dfr_perm;	/* request for deferred ACKs permitted */
+	rxrpc_seq_t		ackr_dfr_seq;	/* seqno for deferred ACK */
+	struct rxrpc_ackpacket	ackr;		/* pending normal ACK packet */
+	u8			ackr_array[RXRPC_CALL_ACK_WINDOW_SIZE];	/* ACK records */
+
+	/* presentation layer */
+	char			app_last_rcv;	/* T if received last packet from remote end */
+	enum rxrpc_app_cstate	app_call_state;	/* call state */
+	enum rxrpc_app_estate	app_err_state;	/* abort/error state */
+	struct list_head	app_readyq;	/* ordered ready received packet queue */
+	struct list_head	app_unreadyq;	/* ordered post-hole recv'd packet queue */
+	rxrpc_seq_t		app_ready_seq;	/* last seq number dropped into readyq */
+	size_t			app_ready_qty;	/* amount of data ready in readyq */
+	unsigned		app_opcode;	/* operation ID */
+	unsigned		app_abort_code;	/* abort code (when aborted) */
+	int			app_errno;	/* error number (when ICMP error received) */
+
+	/* statisics */
+	unsigned		pkt_rcv_count;	/* count of received packets on this call */
+	unsigned		pkt_snd_count;	/* count of sent packets on this call */
+	unsigned		app_read_count;	/* number of reads issued */
+
+	/* bits for the application to use */
+	rxrpc_call_attn_func_t	app_attn_func;	/* callback when attention required */
+	rxrpc_call_error_func_t	app_error_func;	/* callback when abort sent (cleanup and put) */
+	rxrpc_call_aemap_func_t	app_aemap_func;	/* callback to map abort code to/from errno */
+	void			*app_user;	/* application data */
+	struct list_head	app_link;	/* application list linkage */
+	struct list_head	app_attn_link;	/* application attention list linkage */
+	size_t			app_mark;	/* trigger callback when app_ready_qty>=app_mark */
+	char			app_async_read;	/* T if in async-read mode */
+	u8			*app_read_buf;	/* application async read buffer (app_mark size) */
+	u8			*app_scr_alloc;	/* application scratch allocation pointer */
+	void			*app_scr_ptr;	/* application pointer into scratch buffer */
+
+#define RXRPC_APP_MARK_EOF 0xFFFFFFFFU	/* mark at end of input */
+
+	/* application scratch buffer */
+	u8		app_scratch[0] __attribute__((aligned(sizeof(long))));
+};
+
+#define RXRPC_CALL_SCRATCH_SIZE (PAGE_SIZE - sizeof(struct rxrpc_call))
+
+#define rxrpc_call_reset_scratch(CALL) \
+do { (CALL)->app_scr_alloc = (CALL)->app_scratch; } while(0)
+
+#define rxrpc_call_alloc_scratch(CALL,SIZE)						\
+({											\
+	void *ptr;									\
+	ptr = (CALL)->app_scr_alloc;							\
+	(CALL)->app_scr_alloc += (SIZE);						\
+	if ((SIZE)>RXRPC_CALL_SCRATCH_SIZE ||						\
+	    (size_t)((CALL)->app_scr_alloc - (u8*)(CALL)) > RXRPC_CALL_SCRATCH_SIZE) {	\
+		printk("rxrpc_call_alloc_scratch(%p,%u)\n",(CALL),(SIZE));		\
+		BUG();									\
+	}										\
+	ptr;										\
+})
+
+#define rxrpc_call_alloc_scratch_s(CALL,TYPE)						\
+({											\
+	size_t size = sizeof(TYPE);							\
+	TYPE *ptr;									\
+	ptr = (TYPE*)(CALL)->app_scr_alloc;						\
+	(CALL)->app_scr_alloc += size;							\
+	if (size>RXRPC_CALL_SCRATCH_SIZE ||						\
+	    (size_t)((CALL)->app_scr_alloc - (u8*)(CALL)) > RXRPC_CALL_SCRATCH_SIZE) {	\
+		printk("rxrpc_call_alloc_scratch(%p,%u)\n",(CALL),size);		\
+		BUG();									\
+	}										\
+	ptr;										\
+})
+
+#define rxrpc_call_is_ack_pending(CALL) ((CALL)->ackr.reason != 0)
+
+extern int rxrpc_create_call(struct rxrpc_connection *conn,
+			     rxrpc_call_attn_func_t attn,
+			     rxrpc_call_error_func_t error,
+			     rxrpc_call_aemap_func_t aemap,
+			     struct rxrpc_call **_call);
+
+extern int rxrpc_incoming_call(struct rxrpc_connection *conn,
+			       struct rxrpc_message *msg,
+			       struct rxrpc_call **_call);
+
+static inline void rxrpc_get_call(struct rxrpc_call *call)
+{
+	if (atomic_read(&call->usage)<=0)
+		BUG();
+	atomic_inc(&call->usage);
+	/*printk("rxrpc_get_call(%p{u=%d})\n",(C),atomic_read(&(C)->usage));*/
+}
+
+extern void rxrpc_put_call(struct rxrpc_call *call);
+
+extern void rxrpc_call_do_stuff(struct rxrpc_call *call);
+
+extern int rxrpc_call_abort(struct rxrpc_call *call, int error);
+
+#define RXRPC_CALL_READ_BLOCK	0x0001	/* block if not enough data and not yet EOF */
+#define RXRPC_CALL_READ_ALL	0x0002	/* error if insufficient data received */
+extern int rxrpc_call_read_data(struct rxrpc_call *call, void *buffer, size_t size, int flags);
+
+extern int rxrpc_call_write_data(struct rxrpc_call *call,
+				 size_t sioc,
+				 struct iovec siov[],
+				 u8 rxhdr_flags,
+				 int alloc_flags,
+				 int dup_data,
+				 size_t *size_sent);
+
+extern int rxrpc_call_flush(struct rxrpc_call *call);
+
+extern void rxrpc_call_handle_error(struct rxrpc_call *conn, int local, int errno);
+
+#endif /* _LINUX_RXRPC_CALL_H */

include/rxrpc/connection.h

+/* connection.h: Rx connection record
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_CONNECTION_H
+#define _LINUX_RXRPC_CONNECTION_H
+
+#include <rxrpc/types.h>
+#include <rxrpc/krxtimod.h>
+
+struct sk_buff;
+
+/*****************************************************************************/
+/*
+ * Rx connection
+ * - connections are matched by (rmt_port,rmt_addr,service_id,conn_id,clientflag)
+ * - connections only retain a refcount on the peer when they are active
+ * - connections with refcount==0 are inactive and reside in the peer's graveyard
+ */
+struct rxrpc_connection
+{
+	atomic_t		usage;
+	struct rxrpc_transport	*trans;		/* transport endpoint */
+	struct rxrpc_peer	*peer;		/* peer from/to which connected */
+	struct rxrpc_service	*service;	/* responsible service (inbound conns) */
+	struct rxrpc_timer	timeout;	/* decaching timer */
+	struct list_head	link;		/* link in peer's list */
+	struct list_head	proc_link;	/* link in proc list */
+	struct list_head	err_link;	/* link in ICMP error processing list */
+	struct sockaddr_in	addr;		/* remote address */
+	struct rxrpc_call	*channels[4];	/* channels (active calls) */
+	wait_queue_head_t	chanwait;	/* wait for channel to become available */
+	spinlock_t		lock;		/* access lock */
+	struct timeval		atime;		/* last access time */
+	size_t			mtu_size;	/* MTU size for outbound messages */
+	unsigned		call_counter;	/* call ID counter */
+	rxrpc_serial_t		serial_counter;	/* packet serial number counter */
+
+	/* the following should all be in net order */
+	u32			in_epoch;	/* peer's epoch */
+	u32			out_epoch;	/* my epoch */
+	u32			conn_id;	/* connection ID, appropriately shifted */
+	u16			service_id;	/* service ID */
+	u8			security_ix;	/* security ID */
+	u8			in_clientflag;	/* RXRPC_CLIENT_INITIATED if we are server */
+	u8			out_clientflag;	/* RXRPC_CLIENT_INITIATED if we are client */
+};
+
+extern int rxrpc_create_connection(struct rxrpc_transport *trans,
+				   u16 port,
+				   u32 addr,
+				   unsigned short service_id,
+				   void *security,
+				   struct rxrpc_connection **_conn);
+
+extern int rxrpc_connection_lookup(struct rxrpc_peer *peer,
+				   struct rxrpc_message *msg,
+				   struct rxrpc_connection **_conn);
+
+static inline void rxrpc_get_connection(struct rxrpc_connection *conn)
+{
+	if (atomic_read(&conn->usage)<0)
+		BUG();
+	atomic_inc(&conn->usage);
+	//printk("rxrpc_get_conn(%p{u=%d})\n",conn,atomic_read(&conn->usage));
+}
+
+extern void rxrpc_put_connection(struct rxrpc_connection *conn);
+
+extern int rxrpc_conn_receive_call_packet(struct rxrpc_connection *conn,
+					  struct rxrpc_call *call,
+					  struct rxrpc_message *msg);
+
+extern void rxrpc_conn_handle_error(struct rxrpc_connection *conn, int local, int errno);
+
+#endif /* _LINUX_RXRPC_CONNECTION_H */

include/rxrpc/krxiod.h

+/* krxiod.h: Rx RPC I/O kernel thread interface
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_KRXIOD_H
+#define _LINUX_RXRPC_KRXIOD_H
+
+#include <rxrpc/types.h>
+
+extern int rxrpc_krxiod_init(void);
+extern void rxrpc_krxiod_kill(void);
+extern void rxrpc_krxiod_queue_transport(struct rxrpc_transport *trans);
+extern void rxrpc_krxiod_dequeue_transport(struct rxrpc_transport *trans);
+extern void rxrpc_krxiod_queue_peer(struct rxrpc_peer *peer);
+extern void rxrpc_krxiod_dequeue_peer(struct rxrpc_peer *peer);
+extern void rxrpc_krxiod_clear_peers(struct rxrpc_transport *trans);
+extern void rxrpc_krxiod_queue_call(struct rxrpc_call *call);
+extern void rxrpc_krxiod_dequeue_call(struct rxrpc_call *call);
+
+#endif /* _LINUX_RXRPC_KRXIOD_H */

include/rxrpc/krxsecd.h

+/* krxsecd.h: Rx RPC security kernel thread interface
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_KRXSECD_H
+#define _LINUX_RXRPC_KRXSECD_H
+
+#include <rxrpc/types.h>
+
+extern int rxrpc_krxsecd_init(void);
+extern void rxrpc_krxsecd_kill(void);
+extern void rxrpc_krxsecd_clear_transport(struct rxrpc_transport *trans);
+extern void rxrpc_krxsecd_queue_incoming_call(struct rxrpc_message *msg);
+
+#endif /* _LINUX_RXRPC_KRXSECD_H */

include/rxrpc/krxtimod.h

+/* krxtimod.h: RxRPC timeout daemon
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_KRXTIMOD_H
+#define _LINUX_RXRPC_KRXTIMOD_H
+
+#include <rxrpc/types.h>
+
+struct rxrpc_timer_ops {
+	/* called when the front of the timer queue has timed out */
+	void (*timed_out)(struct rxrpc_timer *timer);
+};
+
+/*****************************************************************************/
+/*
+ * RXRPC timer/timeout record
+ */
+struct rxrpc_timer
+{
+	struct list_head		link;		/* link in timer queue */
+	unsigned long			timo_jif;	/* timeout time */
+	const struct rxrpc_timer_ops	*ops;		/* timeout expiry function */
+};
+
+static inline void rxrpc_timer_init(rxrpc_timer_t *timer, const struct rxrpc_timer_ops *ops)
+{
+	INIT_LIST_HEAD(&timer->link);
+	timer->ops = ops;
+}
+
+extern int rxrpc_krxtimod_start(void);
+extern void rxrpc_krxtimod_kill(void);
+
+extern void rxrpc_krxtimod_add_timer(rxrpc_timer_t *timer, unsigned long timeout);
+extern int rxrpc_krxtimod_del_timer(rxrpc_timer_t *timer);
+
+#endif /* _LINUX_RXRPC_KRXTIMOD_H */

include/rxrpc/message.h

+/* message.h: Rx message caching
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _H_3AD3363A_3A9C_11D6_83D8_0002B3163499
+#define _H_3AD3363A_3A9C_11D6_83D8_0002B3163499
+
+#include <rxrpc/packet.h>
+
+/*****************************************************************************/
+/*
+ * Rx message record
+ */
+struct rxrpc_message
+{
+	atomic_t		usage;
+	struct list_head	link;		/* list link */
+	struct timeval		stamp;		/* time received or last sent */
+	rxrpc_seq_t		seq;		/* message sequence number */
+
+	int			state;		/* the state the message is currently in */
+#define RXRPC_MSG_PREPARED	0
+#define RXRPC_MSG_SENT		1
+#define RXRPC_MSG_ACKED		2		/* provisionally ACK'd */
+#define RXRPC_MSG_DONE		3		/* definitively ACK'd (msg->seq<ack.firstPacket) */
+#define RXRPC_MSG_RECEIVED	4
+#define RXRPC_MSG_ERROR		-1
+	char			rttdone;	/* used for RTT */
+
+	struct rxrpc_transport	*trans;		/* transport received through */
+	struct rxrpc_connection	*conn;		/* connection received over */
+	struct sk_buff		*pkt;		/* received packet */
+	off_t			offset;		/* offset into pkt of next byte of data */
+
+	struct rxrpc_header	hdr;		/* message header */
+
+	int			dcount;		/* data part count */
+	size_t			dsize;		/* data size */
+#define RXRPC_MSG_MAX_IOCS 8
+	struct iovec		data[RXRPC_MSG_MAX_IOCS]; /* message data */
+	unsigned long		dfree;		/* bit mask indicating kfree(data[x]) if T */
+};
+
+#define rxrpc_get_message(M) do { atomic_inc(&(M)->usage); } while(0)
+
+extern void __rxrpc_put_message(struct rxrpc_message *msg);
+static inline void rxrpc_put_message(struct rxrpc_message *msg)
+{
+	if (atomic_read(&msg->usage)<=0)
+		BUG();
+	if (atomic_dec_and_test(&msg->usage))
+		__rxrpc_put_message(msg);
+}
+
+extern int rxrpc_conn_newmsg(struct rxrpc_connection *conn,
+			     struct rxrpc_call *call,
+			     u8 type,
+			     int count,
+			     struct iovec diov[],
+			     int alloc_flags,
+			     struct rxrpc_message **_msg);
+
+extern int rxrpc_conn_sendmsg(struct rxrpc_connection *conn, struct rxrpc_message *msg);
+
+#endif /* _H_3AD3363A_3A9C_11D6_83D8_0002B3163499 */

include/rxrpc/packet.h

+/* packet.h: Rx packet layout and definitions
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_PACKET_H
+#define _LINUX_RXRPC_PACKET_H
+
+#include <rxrpc/types.h>
+
+#define RXRPC_IPUDP_SIZE		28
+extern size_t RXRPC_MAX_PACKET_SIZE;
+#define RXRPC_MAX_PACKET_DATA_SIZE	(RXRPC_MAX_PACKET_SIZE - sizeof(struct rxrpc_header))
+#define RXRPC_LOCAL_PACKET_SIZE		RXRPC_MAX_PACKET_SIZE
+#define RXRPC_REMOTE_PACKET_SIZE	(576 - RXRPC_IPUDP_SIZE)
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx packet header
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_header
+{
+	u32	epoch;		/* client boot timestamp */
+
+	u32	cid;		/* connection and channel ID */
+#define RXRPC_MAXCALLS		4			/* max active calls per conn */
+#define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
+#define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */
+#define RXRPC_CIDSHIFT		2			/* shift for connection ID */
+
+	u32	callNumber;	/* call ID (0 for connection-level packets) */
+#define RXRPC_PROCESS_MAXCALLS	(1<<2)	/* maximum number of active calls per conn (power of 2) */
+
+	u32	seq;		/* sequence number of pkt in call stream */
+	u32	serial;		/* serial number of pkt sent to network */
+
+	u8	type;		/* packet type */
+#define RXRPC_PACKET_TYPE_DATA		1	/* data */
+#define RXRPC_PACKET_TYPE_ACK		2	/* ACK */
+#define RXRPC_PACKET_TYPE_BUSY		3	/* call reject */
+#define RXRPC_PACKET_TYPE_ABORT		4	/* call/connection abort */
+#define RXRPC_PACKET_TYPE_ACKALL	5	/* ACK all outstanding packets on call */
+#define RXRPC_PACKET_TYPE_CHALLENGE	6	/* connection security challenge (SRVR->CLNT) */
+#define RXRPC_PACKET_TYPE_RESPONSE	7	/* connection secutity response (CLNT->SRVR) */
+#define RXRPC_PACKET_TYPE_DEBUG		8	/* debug info request */
+#define RXRPC_N_PACKET_TYPES		9	/* number of packet types (incl type 0) */
+
+	u8	flags;		/* packet flags */
+#define RXRPC_CLIENT_INITIATED	0x01		/* signifies a packet generated by a client */
+#define RXRPC_REQUEST_ACK	0x02		/* request an unconditional ACK of this packet */
+#define RXRPC_LAST_PACKET	0x04		/* the last packet from this side for this call */
+#define RXRPC_MORE_PACKETS	0x08		/* more packets to come */
+#define RXRPC_JUMBO_PACKET	0x20		/* [DATA] this is a jumbo packet */
+#define RXRPC_SLOW_START_OK	0x20		/* [ACK] slow start supported */
+
+	u8	userStatus;	/* app-layer defined status */
+	u8	securityIndex;	/* security protocol ID */
+	u16	_rsvd;		/* reserved (used by kerberos security as cksum) */
+	u16	serviceId;	/* service ID */
+
+} __attribute__((packed));
+
+#define __rxrpc_header_off(X) offsetof(struct rxrpc_header,X)
+
+extern const char *rxrpc_pkts[];
+
+/*****************************************************************************/
+/*
+ * jumbo packet secondary header
+ * - can be mapped to read header by:
+ *   - new_serial = serial + 1
+ *   - new_seq = seq + 1
+ *   - new_flags = j_flags
+ *   - new__rsvd = j__rsvd
+ *   - duplicating all other fields
+ */
+struct rxrpc_jumbo_header
+{
+	u8	flags;		/* packet flags (as per rxrpc_header) */
+	u8	pad;
+	u16	_rsvd;		/* reserved (used by kerberos security as cksum) */
+};
+
+#define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
+
+/*****************************************************************************/
+/*
+ * on-the-wire Rx ACK packet data payload
+ * - all multibyte fields should be in network byte order
+ */
+struct rxrpc_ackpacket
+{
+	u16	bufferSpace;	/* number of packet buffers available */
+	u16	maxSkew;	/* diff between serno being ACK'd and highest serial no received */
+	u32	firstPacket;	/* sequence no of first ACK'd packet in attached list */
+	u32	previousPacket;	/* sequence no of previous packet received */
+	u32	serial;		/* serial no of packet that prompted this ACK */
+
+	u8	reason;		/* reason for ACK */
+#define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
+#define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
+#define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
+#define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
+#define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
+#define RXRPC_ACK_PING			6	/* keep alive ACK */
+#define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
+#define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
+#define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
+
+	u8	nAcks;		/* number of ACKs */
+#define RXRPC_MAXACKS	255
+
+	u8	acks[0];	/* list of ACK/NAKs */
+#define RXRPC_ACK_TYPE_NACK		0
+#define RXRPC_ACK_TYPE_ACK		1
+
+} __attribute__((packed));
+
+extern const char *rxrpc_acks[];
+
+#endif /* _LINUX_RXRPC_PACKET_H */

include/rxrpc/peer.h

+/* peer.h: Rx RPC per-transport peer record
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_PEER_H
+#define _LINUX_RXRPC_PEER_H
+
+#include <linux/wait.h>
+#include <rxrpc/types.h>
+#include <rxrpc/krxtimod.h>
+
+struct rxrpc_peer_ops
+{
+	/* peer record being added */
+	int (*adding)(struct rxrpc_peer *peer);
+
+	/* peer record being discarded from graveyard */
+	void (*discarding)(struct rxrpc_peer *peer);
+
+	/* change of epoch detected on connection */
+	void (*change_of_epoch)(struct rxrpc_connection *conn);
+};
+
+/*****************************************************************************/
+/*
+ * Rx RPC per-transport peer record
+ * - peers only retain a refcount on the transport when they are active
+ * - peers with refcount==0 are inactive and reside in the transport's graveyard
+ */
+struct rxrpc_peer
+{
+	atomic_t		usage;
+	struct rxrpc_peer_ops	*ops;		/* operations on this peer */
+	struct rxrpc_transport	*trans;		/* owner transport */
+	struct rxrpc_timer	timeout;	/* timeout for grave destruction */
+	struct list_head	link;		/* link in transport's peer list */
+	struct list_head	proc_link;	/* link in /proc list */
+	rwlock_t		conn_lock;	/* lock for connections */
+	struct list_head	conn_active;	/* active connections to/from this peer */
+	struct list_head	conn_graveyard;	/* graveyard for inactive connections */
+	spinlock_t		conn_gylock;	/* lock for conn_graveyard */
+	wait_queue_head_t	conn_gy_waitq;	/* wait queue hit when graveyard is empty */
+	atomic_t		conn_count;	/* number of attached connections */
+	struct in_addr		addr;		/* remote address */
+	size_t			if_mtu;		/* interface MTU for this peer */
+	spinlock_t		lock;		/* access lock */
+
+	void			*user;		/* application layer data */
+
+	/* calculated RTT cache */
+#define RXRPC_RTT_CACHE_SIZE 32
+	suseconds_t		rtt;		/* current RTT estimate (in uS) */
+	unsigned short		rtt_point;	/* next entry at which to insert */
+	unsigned short		rtt_usage;	/* amount of cache actually used */
+	suseconds_t		rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* calculated RTT cache */
+};
+
+
+extern int rxrpc_peer_lookup(struct rxrpc_transport *trans,
+			     u32 addr,
+			     struct rxrpc_peer **_peer);
+
+static inline void rxrpc_get_peer(struct rxrpc_peer *peer)
+{
+	if (atomic_read(&peer->usage)<0)
+		BUG();
+	atomic_inc(&peer->usage);
+	//printk("rxrpc_get_peer(%p{u=%d})\n",peer,atomic_read(&peer->usage));
+}
+
+extern void rxrpc_put_peer(struct rxrpc_peer *peer);
+
+#endif /* _LINUX_RXRPC_PEER_H */

include/rxrpc/rxrpc.h

+/* rx.h: Rx RPC interface
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_RXRPC_H
+#define _LINUX_RXRPC_RXRPC_H
+
+#ifdef __KERNEL__
+
+extern u32 rxrpc_epoch;
+
+extern int rxrpc_ktrace;
+extern int rxrpc_kdebug;
+extern int rxrpc_kproto;
+extern int rxrpc_knet;
+
+extern int rxrpc_sysctl_init(void);
+extern void rxrpc_sysctl_cleanup(void);
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_RXRPC_RXRPC_H */

include/rxrpc/transport.h

+/* transport.h: Rx transport management
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_TRANSPORT_H
+#define _LINUX_RXRPC_TRANSPORT_H
+
+#include <rxrpc/types.h>
+#include <rxrpc/krxiod.h>
+#include <rxrpc/rxrpc.h>
+#include <linux/skbuff.h>
+#include <linux/rwsem.h>
+
+typedef int (*rxrpc_newcall_fnx_t)(struct rxrpc_call *call);
+
+extern wait_queue_head_t rxrpc_krxiod_wq;
+
+/*****************************************************************************/
+/*
+ * Rx operation specification
+ * - tables of these must be sorted by op ID so that they can be binary-chop searched
+ */
+struct rxrpc_operation
+{
+	unsigned		id;		/* operation ID */
+	size_t			asize;		/* minimum size of argument block */
+	const char		*name;		/* name of operation */
+	void			*user;		/* initial user data */
+};
+
+/*****************************************************************************/
+/*
+ * Rx transport service record
+ */
+struct rxrpc_service
+{
+	struct list_head	link;		/* link in services list on transport */
+	struct module		*owner;		/* owner module */
+	rxrpc_newcall_fnx_t	new_call;	/* new call handler function */
+	const char		*name;		/* name of service */
+	unsigned short		service_id;	/* Rx service ID */
+	rxrpc_call_attn_func_t	attn_func;	/* call requires attention callback */
+	rxrpc_call_error_func_t	error_func;	/* call error callback */
+	rxrpc_call_aemap_func_t	aemap_func;	/* abort -> errno mapping callback */
+
+	const struct rxrpc_operation	*ops_begin;	/* beginning of operations table */
+	const struct rxrpc_operation	*ops_end;	/* end of operations table */
+};
+
+/*****************************************************************************/
+/*
+ * Rx transport endpoint record
+ */
+struct rxrpc_transport
+{
+	atomic_t		usage;
+	struct socket		*socket;	/* my UDP socket */
+	struct list_head	services;	/* services listening on this socket */
+	struct list_head	link;		/* link in transport list */
+	struct list_head	proc_link;	/* link in transport proc list */
+	struct list_head	krxiodq_link;	/* krxiod attention queue link */
+	spinlock_t		lock;		/* access lock */
+	struct list_head	peer_active;	/* active peers connected to over this socket */
+	struct list_head	peer_graveyard;	/* inactive peer list */
+	spinlock_t		peer_gylock;	/* peer graveyard lock */
+	wait_queue_head_t	peer_gy_waitq;	/* wait queue hit when peer graveyard is empty */
+	rwlock_t		peer_lock;	/* peer list access lock */
+	atomic_t		peer_count;	/* number of peers */
+	struct rxrpc_peer_ops	*peer_ops;	/* default peer operations */
+	unsigned short		port;		/* port upon which listening */
+	volatile char		error_rcvd;	/* T if received ICMP error outstanding */
+};
+
+extern struct list_head rxrpc_transports;
+
+extern int rxrpc_create_transport(unsigned short port,
+				  struct rxrpc_transport **_trans);
+
+static inline void rxrpc_get_transport(struct rxrpc_transport *trans)
+{
+	if (atomic_read(&trans->usage)<=0)
+		BUG();
+	atomic_inc(&trans->usage);
+	//printk("rxrpc_get_transport(%p{u=%d})\n",trans,atomic_read(&trans->usage));
+}
+
+extern void rxrpc_put_transport(struct rxrpc_transport *trans);
+
+extern int rxrpc_add_service(struct rxrpc_transport *trans,
+			     struct rxrpc_service *srv);
+
+extern void rxrpc_del_service(struct rxrpc_transport *trans,
+			      struct rxrpc_service *srv);
+
+#if 0
+extern int rxrpc_trans_add_connection(struct rxrpc_transport *trans,
+				      struct rxrpc_connection *conn);
+#endif
+
+extern void rxrpc_trans_receive_packet(struct rxrpc_transport *trans);
+
+extern int rxrpc_trans_immediate_abort(struct rxrpc_transport *trans,
+				       struct rxrpc_message *msg,
+				       int error);
+
+extern void rxrpc_clear_transport(struct rxrpc_transport *trans);
+
+#endif /* _LINUX_RXRPC_TRANSPORT_H */

include/rxrpc/types.h

+/* types.h: Rx types
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_RXRPC_TYPES_H
+#define _LINUX_RXRPC_TYPES_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/spinlock.h>
+#include <asm/atomic.h>
+
+typedef unsigned	rxrpc_seq_t;	/* Rx message sequence number */
+typedef unsigned	rxrpc_serial_t;	/* Rx message serial number */
+
+struct rxrpc_call;
+struct rxrpc_connection;
+struct rxrpc_header;
+struct rxrpc_message;
+struct rxrpc_operation;
+struct rxrpc_peer;
+struct rxrpc_service;
+typedef struct rxrpc_timer rxrpc_timer_t;
+struct rxrpc_transport;
+
+typedef void (*rxrpc_call_attn_func_t)(struct rxrpc_call *call);
+typedef void (*rxrpc_call_error_func_t)(struct rxrpc_call *call);
+typedef void (*rxrpc_call_aemap_func_t)(struct rxrpc_call *call);
+
+#endif /* _LINUX_RXRPC_TYPES_H */

net/Makefile

@@ -29,6 +29,7 @@ obj-$(CONFIG_AX25)		+= ax25/
 obj-$(CONFIG_IRDA)		+= irda/
 obj-$(CONFIG_BT)		+= bluetooth/
 obj-$(CONFIG_SUNRPC)		+= sunrpc/
+obj-$(CONFIG_RXRPC)		+= rxrpc/
 obj-$(CONFIG_ATM)		+= atm/
 obj-$(CONFIG_DECNET)		+= decnet/
 obj-$(CONFIG_ECONET)		+= econet/

net/rxrpc/Makefile

+#
+# Makefile for Linux kernel Rx RPC
+#
+
+export-objs := rxrpc_syms.o
+
+rxrpc-objs := \
+	call.o \
+	connection.o \
+	krxiod.o \
+	krxsecd.o \
+	krxtimod.o \
+	main.o \
+	peer.o \
+	rxrpc_syms.o \
+	transport.o
+
+#ifeq ($(CONFIG_PROC_FS),y)
+rxrpc-objs	+= proc.o
+#endif
+#ifeq ($(CONFIG_SYSCTL),y)
+rxrpc-objs += sysctl.o
+#endif
+
+obj-m  := rxrpc.o
+
+# superfluous for 2.5, but needed for 2.4..
+ifeq "$(VERSION).$(PATCHLEVEL)" "2.4"
+rxrpc.o: $(rxrpc-objs)
+	$(LD) -r -o $@ $(rxrpc-objs)
+endif
+
+include $(TOPDIR)/Rules.make

net/rxrpc/call.c

+/* call.c: Rx call routines
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <rxrpc/rxrpc.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/peer.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/call.h>
+#include <rxrpc/message.h>
+#include "internal.h"
+
+__RXACCT_DECL(atomic_t rxrpc_call_count);
+__RXACCT_DECL(atomic_t rxrpc_message_count);
+
+LIST_HEAD(rxrpc_calls);
+DECLARE_RWSEM(rxrpc_calls_sem);
+
+unsigned rxrpc_call_rcv_timeout		= 30;
+unsigned rxrpc_call_acks_timeout	= 30;
+unsigned rxrpc_call_dfr_ack_timeout	= 5;
+unsigned short rxrpc_call_max_resend	= 10;
+
+const char *rxrpc_call_states[] = {
+	"COMPLETE",
+	"ERROR",
+	"SRVR_RCV_OPID",
+	"SRVR_RCV_ARGS",
+	"SRVR_GOT_ARGS",
+	"SRVR_SND_REPLY",
+	"SRVR_RCV_FINAL_ACK",
+	"CLNT_SND_ARGS",
+	"CLNT_RCV_REPLY",
+	"CLNT_GOT_REPLY"
+};
+
+const char *rxrpc_call_error_states[] = {
+	"NO_ERROR",
+	"LOCAL_ABORT",
+	"PEER_ABORT",
+	"LOCAL_ERROR",
+	"REMOTE_ERROR"
+};
+
+const char *rxrpc_pkts[] = {
+	"?00", "data", "ack", "busy", "abort", "ackall", "chall", "resp", "debug",
+	"?09", "?10", "?11", "?12", "?13", "?14", "?15"
+};
+
+const char *rxrpc_acks[] = {
+	"---", "REQ", "DUP", "SEQ", "WIN", "MEM", "PNG", "PNR", "DLY", "IDL", "-?-"
+};
+
+static const char _acktype[] = "NA-";
+
+static void rxrpc_call_receive_packet(struct rxrpc_call *call);
+static void rxrpc_call_receive_data_packet(struct rxrpc_call *call, struct rxrpc_message *msg);
+static void rxrpc_call_receive_ack_packet(struct rxrpc_call *call, struct rxrpc_message *msg);
+static void rxrpc_call_definitively_ACK(struct rxrpc_call *call, rxrpc_seq_t higest);
+static void rxrpc_call_resend(struct rxrpc_call *call, rxrpc_seq_t highest);
+static int __rxrpc_call_read_data(struct rxrpc_call *call);
+
+static int rxrpc_call_record_ACK(struct rxrpc_call *call,
+				 struct rxrpc_message *msg,
+				 rxrpc_seq_t seq,
+				 size_t count);
+#define _state(call) \
+	_debug("[[[ state %s ]]]",rxrpc_call_states[call->app_call_state]);
+
+static void rxrpc_call_default_attn_func(struct rxrpc_call *call)
+{
+	wake_up(&call->waitq);
+}
+
+static void rxrpc_call_default_error_func(struct rxrpc_call *call)
+{
+	wake_up(&call->waitq);
+}
+
+static void rxrpc_call_default_aemap_func(struct rxrpc_call *call)
+{
+	switch (call->app_err_state) {
+	case RXRPC_ESTATE_LOCAL_ABORT:
+		call->app_abort_code = -call->app_errno;
+	case RXRPC_ESTATE_PEER_ABORT:
+		call->app_errno = -ECONNABORTED;
+	default:
+		break;
+	}
+}
+
+static void __rxrpc_call_acks_timeout(unsigned long _call)
+{
+	struct rxrpc_call *call = (struct rxrpc_call *) _call;
+
+	_debug("ACKS TIMEOUT %05lu",jiffies - call->cjif);
+
+	call->flags |= RXRPC_CALL_ACKS_TIMO;
+	rxrpc_krxiod_queue_call(call);
+}
+
+static void __rxrpc_call_rcv_timeout(unsigned long _call)
+{
+	struct rxrpc_call *call = (struct rxrpc_call *) _call;
+
+	_debug("RCV TIMEOUT %05lu",jiffies - call->cjif);
+
+	call->flags |= RXRPC_CALL_RCV_TIMO;
+	rxrpc_krxiod_queue_call(call);
+}
+
+static void __rxrpc_call_ackr_timeout(unsigned long _call)
+{
+	struct rxrpc_call *call = (struct rxrpc_call *) _call;
+
+	_debug("ACKR TIMEOUT %05lu",jiffies - call->cjif);
+
+	call->flags |= RXRPC_CALL_ACKR_TIMO;
+	rxrpc_krxiod_queue_call(call);
+}
+
+/*****************************************************************************/
+/*
+ * create a new call record
+ */
+static inline int __rxrpc_create_call(struct rxrpc_connection *conn,
+				      struct rxrpc_call **_call)
+{
+	struct rxrpc_call *call;
+
+	_enter("%p",conn);
+
+	/* allocate and initialise a call record */
+	call = (struct rxrpc_call *) get_zeroed_page(GFP_KERNEL);
+	if (!call) {
+		_leave(" ENOMEM");
+		return -ENOMEM;
+	}
+
+	atomic_set(&call->usage,1);
+
+	init_waitqueue_head(&call->waitq);
+	spin_lock_init(&call->lock);
+	INIT_LIST_HEAD(&call->link);
+	INIT_LIST_HEAD(&call->acks_pendq);
+	INIT_LIST_HEAD(&call->rcv_receiveq);
+	INIT_LIST_HEAD(&call->rcv_krxiodq_lk);
+	INIT_LIST_HEAD(&call->app_readyq);
+	INIT_LIST_HEAD(&call->app_unreadyq);
+	INIT_LIST_HEAD(&call->app_link);
+	INIT_LIST_HEAD(&call->app_attn_link);
+
+	init_timer(&call->acks_timeout);
+	call->acks_timeout.data = (unsigned long) call;
+	call->acks_timeout.function = __rxrpc_call_acks_timeout;
+
+	init_timer(&call->rcv_timeout);
+	call->rcv_timeout.data = (unsigned long) call;
+	call->rcv_timeout.function = __rxrpc_call_rcv_timeout;
+
+	init_timer(&call->ackr_dfr_timo);
+	call->ackr_dfr_timo.data = (unsigned long) call;
+	call->ackr_dfr_timo.function = __rxrpc_call_ackr_timeout;
+
+	call->conn = conn;
+	call->ackr_win_bot = 1;
+	call->ackr_win_top = call->ackr_win_bot + RXRPC_CALL_ACK_WINDOW_SIZE - 1;
+	call->ackr_prev_seq = 0;
+	call->app_mark = RXRPC_APP_MARK_EOF;
+	call->app_attn_func = rxrpc_call_default_attn_func;
+	call->app_error_func = rxrpc_call_default_error_func;
+	call->app_aemap_func = rxrpc_call_default_aemap_func;
+	call->app_scr_alloc = call->app_scratch;
+
+	call->cjif = jiffies;
+
+	_leave(" = 0 (%p)",call);
+
+	*_call = call;
+
+	return 0;
+} /* end __rxrpc_create_call() */
+
+/*****************************************************************************/
+/*
+ * create a new call record for outgoing calls
+ */
+int rxrpc_create_call(struct rxrpc_connection *conn,
+		      rxrpc_call_attn_func_t attn,
+		      rxrpc_call_error_func_t error,
+		      rxrpc_call_aemap_func_t aemap,
+		      struct rxrpc_call **_call)
+{
+	DECLARE_WAITQUEUE(myself,current);
+
+	struct rxrpc_call *call;
+	int ret, cix, loop;
+
+	_enter("%p",conn);
+
+	/* allocate and initialise a call record */
+	ret = __rxrpc_create_call(conn,&call);
+	if (ret<0) {
+		_leave(" = %d",ret);
+		return ret;
+	}
+
+	call->app_call_state = RXRPC_CSTATE_CLNT_SND_ARGS;
+	if (attn) call->app_attn_func = attn;
+	if (error) call->app_error_func = error;
+	if (aemap) call->app_aemap_func = aemap;
+
+	_state(call);
+
+	spin_lock(&conn->lock);
+	set_current_state(TASK_INTERRUPTIBLE);
+	add_wait_queue(&conn->chanwait,&myself);
+
+ try_again:
+	/* try to find an unused channel */
+	for (cix=0; cix<4; cix++)
+		if (!conn->channels[cix])
+			goto obtained_chan;
+
+	/* no free channels - wait for one to become available */
+	ret = -EINTR;
+	if (signal_pending(current))
+		goto error_unwait;
+
+	spin_unlock(&conn->lock);
+
+	schedule();
+	set_current_state(TASK_INTERRUPTIBLE);
+
+	spin_lock(&conn->lock);
+	goto try_again;
+
+	/* got a channel - now attach to the connection */
+ obtained_chan:
+	remove_wait_queue(&conn->chanwait,&myself);
+	set_current_state(TASK_RUNNING);
+
+	/* concoct a unique call number */
+ next_callid:
+	call->call_id = htonl(++conn->call_counter);
+	for (loop=0; loop<4; loop++)
+		if (conn->channels[loop] && conn->channels[loop]->call_id==call->call_id)
+			goto next_callid;
+
+	rxrpc_get_connection(conn);
+	conn->channels[cix] = call; /* assign _after_ done callid check loop */
+	do_gettimeofday(&conn->atime);
+	call->chan_ix = htonl(cix);
+
+	spin_unlock(&conn->lock);
+
+	down_write(&rxrpc_calls_sem);
+	list_add_tail(&call->call_link,&rxrpc_calls);
+	up_write(&rxrpc_calls_sem);
+
+	__RXACCT(atomic_inc(&rxrpc_call_count));
+	*_call = call;
+
+	_leave(" = 0 (call=%p cix=%u)",call,cix);
+	return 0;
+
+ error_unwait:
+	remove_wait_queue(&conn->chanwait,&myself);
+	set_current_state(TASK_RUNNING);
+	spin_unlock(&conn->lock);
+
+	free_page((unsigned long)call);
+	_leave(" = %d",ret);
+	return ret;
+
+} /* end rxrpc_create_call() */
+
+/*****************************************************************************/
+/*
+ * create a new call record for incoming calls
+ */
+int rxrpc_incoming_call(struct rxrpc_connection *conn,
+			struct rxrpc_message *msg,
+			struct rxrpc_call **_call)
+{
+	struct rxrpc_call *call;
+	unsigned cix;
+	int ret;
+
+	cix = ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK;
+
+	_enter("%p,%u,%u",conn,ntohl(msg->hdr.callNumber),cix);
+
+	/* allocate and initialise a call record */
+	ret = __rxrpc_create_call(conn,&call);
+	if (ret<0) {
+		_leave(" = %d",ret);
+		return ret;
+	}
+
+	call->pkt_rcv_count = 1;
+	call->app_call_state = RXRPC_CSTATE_SRVR_RCV_OPID;
+	call->app_mark = sizeof(u32);
+
+	_state(call);
+
+	/* attach to the connection */
+	ret = -EBUSY;
+	call->chan_ix = htonl(cix);
+	call->call_id = msg->hdr.callNumber;
+
+	spin_lock(&conn->lock);
+
+	if (!conn->channels[cix]) {
+		conn->channels[cix] = call;
+		rxrpc_get_connection(conn);
+		ret = 0;
+	}
+
+	spin_unlock(&conn->lock);
+
+	if (ret<0) free_page((unsigned long)call);
+
+	_leave(" = %p",call);
+
+	if (ret==0) {
+		down_write(&rxrpc_calls_sem);
+		list_add_tail(&call->call_link,&rxrpc_calls);
+		up_write(&rxrpc_calls_sem);
+		__RXACCT(atomic_inc(&rxrpc_call_count));
+		*_call = call;
+	}
+
+	return ret;
+} /* end rxrpc_incoming_call() */
+
+/*****************************************************************************/
+/*
+ * free a call record
+ */
+void rxrpc_put_call(struct rxrpc_call *call)
+{
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_message *msg;
+
+	_enter("%p{u=%d}",call,atomic_read(&call->usage));
+
+	/* sanity check */
+	if (atomic_read(&call->usage)<=0)
+		BUG();
+
+	/* to prevent a race, the decrement and the de-list must be effectively atomic */
+	spin_lock(&conn->lock);
+	if (likely(!atomic_dec_and_test(&call->usage))) {
+		spin_unlock(&conn->lock);
+		_leave("");
+		return;
+	}
+
+	conn->channels[ntohl(call->chan_ix)] = NULL;
+
+	spin_unlock(&conn->lock);
+
+	wake_up(&conn->chanwait);
+
+	rxrpc_put_connection(conn);
+
+	/* clear the timers and dequeue from krxiod */
+	del_timer_sync(&call->acks_timeout);
+	del_timer_sync(&call->rcv_timeout);
+	del_timer_sync(&call->ackr_dfr_timo);
+
+	rxrpc_krxiod_dequeue_call(call);
+
+	/* clean up the contents of the struct */
+	if (call->snd_nextmsg)
+		rxrpc_put_message(call->snd_nextmsg);
+
+	if (call->snd_ping)
+		rxrpc_put_message(call->snd_ping);
+
+	while (!list_empty(&call->acks_pendq)) {
+		msg = list_entry(call->acks_pendq.next,struct rxrpc_message,link);
+		list_del(&msg->link);
+		rxrpc_put_message(msg);
+	}
+
+	while (!list_empty(&call->rcv_receiveq)) {
+		msg = list_entry(call->rcv_receiveq.next,struct rxrpc_message,link);
+		list_del(&msg->link);
+		rxrpc_put_message(msg);
+	}
+
+	while (!list_empty(&call->app_readyq)) {
+		msg = list_entry(call->app_readyq.next,struct rxrpc_message,link);
+		list_del(&msg->link);
+		rxrpc_put_message(msg);
+	}
+
+	while (!list_empty(&call->app_unreadyq)) {
+		msg = list_entry(call->app_unreadyq.next,struct rxrpc_message,link);
+		list_del(&msg->link);
+		rxrpc_put_message(msg);
+	}
+
+	if (call->owner) __MOD_DEC_USE_COUNT(call->owner);
+
+	down_write(&rxrpc_calls_sem);
+	list_del(&call->call_link);
+	up_write(&rxrpc_calls_sem);
+
+	__RXACCT(atomic_dec(&rxrpc_call_count));
+	free_page((unsigned long)call);
+
+	_leave(" [destroyed]");
+} /* end rxrpc_put_call() */
+
+/*****************************************************************************/
+/*
+ * actually generate a normal ACK
+ */
+static inline int __rxrpc_call_gen_normal_ACK(struct rxrpc_call *call, rxrpc_seq_t seq)
+{
+	struct rxrpc_message *msg;
+	struct iovec diov[3];
+	unsigned aux[4];
+	int delta, ret;
+
+	/* ACKs default to DELAY */
+	if (!call->ackr.reason)
+		call->ackr.reason = RXRPC_ACK_DELAY;
+
+	_proto("Rx %05lu Sending ACK { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
+	       jiffies - call->cjif,
+	       ntohs(call->ackr.maxSkew),
+	       ntohl(call->ackr.firstPacket),
+	       ntohl(call->ackr.previousPacket),
+	       ntohl(call->ackr.serial),
+	       rxrpc_acks[call->ackr.reason],
+	       call->ackr.nAcks);
+
+	aux[0] = htonl(call->conn->peer->if_mtu);	/* interface MTU */
+	aux[1] = htonl(1444);				/* max MTU */
+	aux[2] = htonl(16);				/* rwind */
+	aux[3] = htonl(4);				/* max packets */
+
+	diov[0].iov_len  = sizeof(struct rxrpc_ackpacket);
+	diov[0].iov_base = &call->ackr;
+	diov[1].iov_len  = (call->ackr_pend_cnt+3);
+	diov[1].iov_base = call->ackr_array;
+	diov[2].iov_len  = sizeof(aux);
+	diov[2].iov_base = &aux;
+
+	/* build and send the message */
+	ret = rxrpc_conn_newmsg(call->conn,call,RXRPC_PACKET_TYPE_ACK,3,diov,GFP_KERNEL,&msg);
+	if (ret<0)
+		goto out;
+
+	msg->seq = seq;
+	msg->hdr.seq = htonl(seq);
+	msg->hdr.flags |= RXRPC_SLOW_START_OK;
+
+	ret = rxrpc_conn_sendmsg(call->conn,msg);
+	rxrpc_put_message(msg);
+	if (ret<0)
+		goto out;
+	call->pkt_snd_count++;
+
+	/* count how many actual ACKs there were at the front */
+	for (delta=0; delta<call->ackr_pend_cnt; delta++)
+		if (call->ackr_array[delta]!=RXRPC_ACK_TYPE_ACK)
+			break;
+
+	call->ackr_pend_cnt -= delta; /* all ACK'd to this point */
+
+	/* crank the ACK window around */
+	if (delta==0) {
+		/* un-ACK'd window */
+	}
+	else if (delta < RXRPC_CALL_ACK_WINDOW_SIZE) {
+		/* partially ACK'd window
+		 * - shuffle down to avoid losing out-of-sequence packets
+		 */
+		call->ackr_win_bot += delta;
+		call->ackr_win_top += delta;
+
+		memmove(&call->ackr_array[0],
+			&call->ackr_array[delta],
+			call->ackr_pend_cnt);
+
+		memset(&call->ackr_array[call->ackr_pend_cnt],
+		       RXRPC_ACK_TYPE_NACK,
+		       sizeof(call->ackr_array) - call->ackr_pend_cnt);
+	}
+	else {
+		/* fully ACK'd window
+		 * - just clear the whole thing
+		 */
+		memset(&call->ackr_array,RXRPC_ACK_TYPE_NACK,sizeof(call->ackr_array));
+	}
+
+	/* clear this ACK */
+	memset(&call->ackr,0,sizeof(call->ackr));
+
+ out:
+	if (!call->app_call_state) printk("___ STATE 0 ___\n");
+	return ret;
+} /* end __rxrpc_call_gen_normal_ACK() */
+
+/*****************************************************************************/
+/*
+ * note the reception of a packet in the call's ACK records and generate an appropriate ACK packet
+ * if necessary
+ * - returns 0 if packet should be processed, 1 if packet should be ignored and -ve on an error
+ */
+static int rxrpc_call_generate_ACK(struct rxrpc_call *call,
+				   struct rxrpc_header *hdr,
+				   struct rxrpc_ackpacket *ack)
+{
+	struct rxrpc_message *msg;
+	rxrpc_seq_t seq;
+	unsigned offset;
+	int ret = 0, err;
+	u8 special_ACK, do_ACK, force;
+
+	_enter("%p,%p { seq=%d tp=%d fl=%02x }",call,hdr,ntohl(hdr->seq),hdr->type,hdr->flags);
+
+	seq = ntohl(hdr->seq);
+	offset = seq - call->ackr_win_bot;
+	do_ACK = RXRPC_ACK_DELAY;
+	special_ACK = 0;
+	force = (seq==1);
+
+	if (call->ackr_high_seq < seq)
+		call->ackr_high_seq = seq;
+
+	/* deal with generation of obvious special ACKs first */
+	if (ack && ack->reason==RXRPC_ACK_PING) {
+		special_ACK = RXRPC_ACK_PING_RESPONSE;
+		ret = 1;
+		goto gen_ACK;
+	}
+
+	if (seq < call->ackr_win_bot) {
+		special_ACK = RXRPC_ACK_DUPLICATE;
+		ret = 1;
+		goto gen_ACK;
+	}
+
+	if (seq >= call->ackr_win_top) {
+		special_ACK = RXRPC_ACK_EXCEEDS_WINDOW;
+		ret = 1;
+		goto gen_ACK;
+	}
+
+	if (call->ackr_array[offset] != RXRPC_ACK_TYPE_NACK) {
+		special_ACK = RXRPC_ACK_DUPLICATE;
+		ret = 1;
+		goto gen_ACK;
+	}
+
+	/* okay... it's a normal data packet inside the ACK window */
+	call->ackr_array[offset] = RXRPC_ACK_TYPE_ACK;
+
+	if (offset<call->ackr_pend_cnt) {
+	}
+	else if (offset>call->ackr_pend_cnt) {
+		do_ACK = RXRPC_ACK_OUT_OF_SEQUENCE;
+		call->ackr_pend_cnt = offset;
+		goto gen_ACK;
+	}
+
+	if (hdr->flags & RXRPC_REQUEST_ACK) {
+		do_ACK = RXRPC_ACK_REQUESTED;
+	}
+
+	/* generate an ACK on the final packet of a reply just received */
+	if (hdr->flags & RXRPC_LAST_PACKET) {
+		if (call->conn->out_clientflag)
+			force = 1;
+	}
+	else if (!(hdr->flags & RXRPC_MORE_PACKETS)) {
+		do_ACK = RXRPC_ACK_REQUESTED;
+	}
+
+	/* re-ACK packets previously received out-of-order */
+	for (offset++; offset<RXRPC_CALL_ACK_WINDOW_SIZE; offset++)
+		if (call->ackr_array[offset]!=RXRPC_ACK_TYPE_ACK)
+			break;
+
+	call->ackr_pend_cnt = offset;
+
+	/* generate an ACK if we fill up the window */
+	if (call->ackr_pend_cnt >= RXRPC_CALL_ACK_WINDOW_SIZE)
+		force = 1;
+
+ gen_ACK:
+	_debug("%05lu ACKs pend=%u norm=%s special=%s%s",
+	       jiffies - call->cjif,
+	       call->ackr_pend_cnt,rxrpc_acks[do_ACK],rxrpc_acks[special_ACK],
+	       force ? " immediate" :
+	       do_ACK==RXRPC_ACK_REQUESTED ? " merge-req" :
+	       hdr->flags & RXRPC_LAST_PACKET ? " finalise" :
+	       " defer"
+	       );
+
+	/* send any pending normal ACKs if need be */
+	if (call->ackr_pend_cnt>0) {
+		/* fill out the appropriate form */
+		call->ackr.bufferSpace		= htons(RXRPC_CALL_ACK_WINDOW_SIZE);
+		call->ackr.maxSkew		= htons(min(call->ackr_high_seq - seq,65535U));
+		call->ackr.firstPacket		= htonl(call->ackr_win_bot);
+		call->ackr.previousPacket	= call->ackr_prev_seq;
+		call->ackr.serial		= hdr->serial;
+		call->ackr.nAcks		= call->ackr_pend_cnt;
+
+		if (do_ACK==RXRPC_ACK_REQUESTED)
+			call->ackr.reason = do_ACK;
+
+		/* generate the ACK immediately if necessary */
+		if (special_ACK || force) {
+			err = __rxrpc_call_gen_normal_ACK(call,do_ACK==RXRPC_ACK_DELAY ? 0 : seq);
+			if (err<0) {
+				ret = err;
+				goto out;
+			}
+		}
+	}
+
+	if (call->ackr.reason==RXRPC_ACK_REQUESTED)
+		call->ackr_dfr_seq = seq;
+
+	/* start the ACK timer if not running if there are any pending deferred ACKs */
+	if (call->ackr_pend_cnt>0 &&
+	    call->ackr.reason!=RXRPC_ACK_REQUESTED &&
+	    !timer_pending(&call->ackr_dfr_timo)
+	    ) {
+		unsigned long timo;
+
+		timo = rxrpc_call_dfr_ack_timeout + jiffies;
+
+		_debug("START ACKR TIMER for cj=%lu",timo-call->cjif);
+
+		spin_lock(&call->lock);
+		mod_timer(&call->ackr_dfr_timo,timo);
+		spin_unlock(&call->lock);
+	}
+	else if ((call->ackr_pend_cnt==0 || call->ackr.reason==RXRPC_ACK_REQUESTED) &&
+		 timer_pending(&call->ackr_dfr_timo)
+		 ) {
+		/* stop timer if no pending ACKs */
+		_debug("CLEAR ACKR TIMER");
+		del_timer_sync(&call->ackr_dfr_timo);
+	}
+
+	/* send a special ACK if one is required */
+	if (special_ACK) {
+		struct rxrpc_ackpacket ack;
+		struct iovec diov[2];
+		u8 acks[1] = { RXRPC_ACK_TYPE_ACK };
+
+		/* fill out the appropriate form */
+		ack.bufferSpace		= htons(RXRPC_CALL_ACK_WINDOW_SIZE);
+		ack.maxSkew		= htons(min(call->ackr_high_seq - seq,65535U));
+		ack.firstPacket		= htonl(call->ackr_win_bot);
+		ack.previousPacket	= call->ackr_prev_seq;
+		ack.serial		= hdr->serial;
+		ack.reason		= special_ACK;
+		ack.nAcks		= 0;
+		//ack.nAcks = special_ACK==RXRPC_ACK_OUT_OF_SEQUENCE ? 0 : hdr->seq ? 1 : 0;
+
+		_proto("Rx Sending s-ACK { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
+		       ntohs(ack.maxSkew),ntohl(ack.firstPacket),ntohl(ack.previousPacket),
+		       ntohl(ack.serial),rxrpc_acks[ack.reason],ack.nAcks);
+
+		diov[0].iov_len  = sizeof(struct rxrpc_ackpacket);
+		diov[0].iov_base = &ack;
+		diov[1].iov_len  = sizeof(acks);
+		diov[1].iov_base = acks;
+
+		/* build and send the message */
+		err = rxrpc_conn_newmsg(call->conn,call,RXRPC_PACKET_TYPE_ACK,
+					hdr->seq ? 2 : 1,diov,
+					GFP_KERNEL,
+					&msg);
+		if (err<0) {
+			ret = err;
+			goto out;
+		}
+
+		msg->seq = seq;
+		msg->hdr.seq = htonl(seq);
+		msg->hdr.flags |= RXRPC_SLOW_START_OK;
+
+		err = rxrpc_conn_sendmsg(call->conn,msg);
+		rxrpc_put_message(msg);
+		if (err<0) {
+			ret = err;
+			goto out;
+		}
+		call->pkt_snd_count++;
+	}
+
+ out:
+	if (hdr->seq)
+		call->ackr_prev_seq = hdr->seq;
+
+	_leave(" = %d",ret);
+	return ret;
+} /* end rxrpc_call_generate_ACK() */
+
+/*****************************************************************************/
+/*
+ * handle work to be done on a call
+ * - includes packet reception and timeout processing
+ */
+void rxrpc_call_do_stuff(struct rxrpc_call *call)
+{
+	_enter("%p{flags=%lx}",call,call->flags);
+
+	/* handle packet reception */
+	if (call->flags & RXRPC_CALL_RCV_PKT) {
+		_debug("- receive packet");
+		call->flags &= ~RXRPC_CALL_RCV_PKT;
+		rxrpc_call_receive_packet(call);
+	}
+
+	/* handle overdue ACKs */
+	if (call->flags & RXRPC_CALL_ACKS_TIMO) {
+		_debug("- overdue ACK timeout");
+		call->flags &= ~RXRPC_CALL_ACKS_TIMO;
+		rxrpc_call_resend(call,call->snd_seq_count);
+	}
+
+	/* handle lack of reception */
+	if (call->flags & RXRPC_CALL_RCV_TIMO) {
+		_debug("- reception timeout");
+		call->flags &= ~RXRPC_CALL_RCV_TIMO;
+		rxrpc_call_abort(call,-EIO);
+	}
+
+	/* handle deferred ACKs */
+	if (call->flags & RXRPC_CALL_ACKR_TIMO ||
+	    (call->ackr.nAcks>0 && call->ackr.reason==RXRPC_ACK_REQUESTED)
+	    ) {
+		_debug("- deferred ACK timeout: cj=%05lu r=%s n=%u",
+		       jiffies - call->cjif,
+		       rxrpc_acks[call->ackr.reason],
+		       call->ackr.nAcks);
+
+		call->flags &= ~RXRPC_CALL_ACKR_TIMO;
+
+		if (call->ackr.nAcks>0 && call->app_call_state!=RXRPC_CSTATE_ERROR) {
+			/* generate ACK */
+			__rxrpc_call_gen_normal_ACK(call,call->ackr_dfr_seq);
+			call->ackr_dfr_seq = 0;
+		}
+	}
+
+	_leave("");
+
+} /* end rxrpc_call_do_timeout() */
+
+/*****************************************************************************/
+/*
+ * send an abort message at call or connection level
+ * - must be called with call->lock held
+ * - the supplied error code is sent as the packet data
+ */
+static int __rxrpc_call_abort(struct rxrpc_call *call, int errno)
+{
+	struct rxrpc_connection *conn = call->conn;
+	struct rxrpc_message *msg;
+	struct iovec diov[1];
+	int ret;
+	u32 _error;
+
+	_enter("%p{%08x},%p{%d},%d",conn,ntohl(conn->conn_id),call,ntohl(call->call_id),errno);
+
+	/* if this call is already aborted, then just wake up any waiters */
+	if (call->app_call_state==RXRPC_CSTATE_ERROR) {
+		spin_unlock(&call->lock);
+		call->app_error_func(call);
+		_leave(" = 0");
+		return 0;
+	}
+
+	rxrpc_get_call(call);
+
+	/* change the state _with_ the lock still held */
+	call->app_call_state = RXRPC_CSTATE_ERROR;
+	call->app_err_state = RXRPC_ESTATE_LOCAL_ABORT;
+	call->app_errno = errno;
+	call->app_mark = RXRPC_APP_MARK_EOF;
+	call->app_read_buf = NULL;
+	call->app_async_read = 0;
+
+	_state(call);
+
+	/* ask the app to translate the error code */
+	call->app_aemap_func(call);
+
+	spin_unlock(&call->lock);
+
+	/* flush any outstanding ACKs */
+	del_timer_sync(&call->acks_timeout);
+	del_timer_sync(&call->rcv_timeout);
+	del_timer_sync(&call->ackr_dfr_timo);
+
+	if (rxrpc_call_is_ack_pending(call))
+		__rxrpc_call_gen_normal_ACK(call,0);
+
+	/* send the abort packet only if we actually traded some other packets */
+	ret = 0;
+	if (call->pkt_snd_count || call->pkt_rcv_count) {
+		/* actually send the abort */
+		_proto("Rx Sending Call ABORT { data=%d }",call->app_abort_code);
+
+		_error = htonl(call->app_abort_code);
+
+		diov[0].iov_len  = sizeof(_error);
+		diov[0].iov_base = &_error;
+
+		ret = rxrpc_conn_newmsg(conn,call,RXRPC_PACKET_TYPE_ABORT,1,diov,GFP_KERNEL,&msg);
+		if (ret==0) {
+			ret = rxrpc_conn_sendmsg(conn,msg);
+			rxrpc_put_message(msg);
+		}
+	}
+
+	/* tell the app layer to let go */
+	call->app_error_func(call);
+
+	rxrpc_put_call(call);
+
+	_leave(" = %d",ret);
+
+	return ret;
+} /* end __rxrpc_call_abort() */
+
+/*****************************************************************************/
+/*
+ * send an abort message at call or connection level
+ * - the supplied error code is sent as the packet data
+ */
+int rxrpc_call_abort(struct rxrpc_call *call, int error)
+{
+	spin_lock(&call->lock);
+
+	return __rxrpc_call_abort(call,error);
+
+} /* end rxrpc_call_abort() */
+
+/*****************************************************************************/
+/*
+ * process packets waiting for this call
+ */
+static void rxrpc_call_receive_packet(struct rxrpc_call *call)
+{
+	struct rxrpc_message *msg;
+	struct list_head *_p;
+	u32 data32;
+
+	_enter("%p",call);
+
+	rxrpc_get_call(call); /* must not go away too soon if aborted by app-layer */
+
+	while (!list_empty(&call->rcv_receiveq)) {
+		/* try to get next packet */
+		_p = NULL;
+		spin_lock(&call->lock);
+		if (!list_empty(&call->rcv_receiveq)) {
+			_p = call->rcv_receiveq.next;
+			list_del_init(_p);
+		}
+		spin_unlock(&call->lock);
+
+		if (!_p) break;
+
+		msg = list_entry(_p,struct rxrpc_message,link);
+
+		_proto("Rx %05lu Received %s packet (%%%u,#%u,%c%c%c%c%c)",
+		       jiffies - call->cjif,
+		       rxrpc_pkts[msg->hdr.type],
+		       ntohl(msg->hdr.serial),
+		       msg->seq,
+		       msg->hdr.flags & RXRPC_JUMBO_PACKET	? 'j' : '-',
+		       msg->hdr.flags & RXRPC_MORE_PACKETS	? 'm' : '-',
+		       msg->hdr.flags & RXRPC_LAST_PACKET	? 'l' : '-',
+		       msg->hdr.flags & RXRPC_REQUEST_ACK	? 'r' : '-',
+		       msg->hdr.flags & RXRPC_CLIENT_INITIATED	? 'C' : 'S'
+		       );
+
+		switch (msg->hdr.type) {
+			/* deal with data packets */
+		case RXRPC_PACKET_TYPE_DATA:
+			/* ACK the packet if necessary */
+			switch (rxrpc_call_generate_ACK(call,&msg->hdr,NULL)) {
+			case 0: /* useful packet */
+				rxrpc_call_receive_data_packet(call,msg);
+				break;
+			case 1: /* duplicate or out-of-window packet */
+				break;
+			default:
+				rxrpc_put_message(msg);
+				goto out;
+			}
+			break;
+
+			/* deal with ACK packets */
+		case RXRPC_PACKET_TYPE_ACK:
+			rxrpc_call_receive_ack_packet(call,msg);
+			break;
+
+			/* deal with abort packets */
+		case RXRPC_PACKET_TYPE_ABORT:
+			data32 = 0;
+			if (skb_copy_bits(msg->pkt,msg->offset,&data32,sizeof(data32))<0) {
+				printk("Rx Received short ABORT packet\n");
+			}
+			else {
+				data32 = ntohl(data32);
+			}
+
+			_proto("Rx Received Call ABORT { data=%d }",data32);
+
+			spin_lock(&call->lock);
+			call->app_call_state = RXRPC_CSTATE_ERROR;
+			call->app_err_state = RXRPC_ESTATE_PEER_ABORT;
+			call->app_abort_code = data32;
+			call->app_errno = -ECONNABORTED;
+			call->app_mark = RXRPC_APP_MARK_EOF;
+			call->app_read_buf = NULL;
+			call->app_async_read = 0;
+
+			/* ask the app to translate the error code */
+			call->app_aemap_func(call);
+			_state(call);
+			spin_unlock(&call->lock);
+			call->app_error_func(call);
+			break;
+
+		default:
+			/* deal with other packet types */
+			_proto("Rx Unsupported packet type %u (#%u)",msg->hdr.type,msg->seq);
+			break;
+		}
+
+		rxrpc_put_message(msg);
+	}
+
+ out:
+	rxrpc_put_call(call);
+	_leave("");
+} /* end rxrpc_call_receive_packet() */
+
+/*****************************************************************************/
+/*
+ * process next data packet
+ * - as the next data packet arrives:
+ *   - it is queued on app_readyq _if_ it is the next one expected (app_ready_seq+1)
+ *   - it is queued on app_unreadyq _if_ it is not the next one expected
+ *   - if a packet placed on app_readyq completely fills a hole leading up to the first packet
+ *     on app_unreadyq, then packets now in sequence are tranferred to app_readyq
+ * - the application layer can only see packets on app_readyq (app_ready_qty bytes)
+ * - the application layer is prodded every time a new packet arrives
+ */
+static void rxrpc_call_receive_data_packet(struct rxrpc_call *call, struct rxrpc_message *msg)
+{
+	const struct rxrpc_operation *optbl, *op;
+	struct rxrpc_message *pmsg;
+	struct list_head *_p;
+	int ret, lo, hi, rmtimo;
+	u32 opid;
+
+	_enter("%p{%u},%p{%u}",call,ntohl(call->call_id),msg,msg->seq);
+
+	rxrpc_get_message(msg);
+
+	/* add to the unready queue if we'd have to create a hole in the ready queue otherwise */
+	if (msg->seq != call->app_ready_seq+1) {
+		_debug("Call add packet %d to unreadyq",msg->seq);
+
+		/* insert in seq order */
+		list_for_each(_p,&call->app_unreadyq) {
+			pmsg = list_entry(_p,struct rxrpc_message,link);
+			if (pmsg->seq>msg->seq)
+				break;
+		}
+
+		list_add_tail(&msg->link,_p);
+
+		_leave(" [unreadyq]");
+		return;
+	}
+
+	/* next in sequence - simply append into the call's ready queue */
+	_debug("Call add packet %d to readyq (+%d => %d bytes)",
+	       msg->seq,msg->dsize,call->app_ready_qty);
+
+	spin_lock(&call->lock);
+	call->app_ready_seq = msg->seq;
+	call->app_ready_qty += msg->dsize;
+	list_add_tail(&msg->link,&call->app_readyq);
+
+	/* move unready packets to the readyq if we got rid of a hole */
+	while (!list_empty(&call->app_unreadyq)) {
+		pmsg = list_entry(call->app_unreadyq.next,struct rxrpc_message,link);
+
+		if (pmsg->seq != call->app_ready_seq+1)
+			break;
+
+		/* next in sequence - just move list-to-list */
+		_debug("Call transfer packet %d to readyq (+%d => %d bytes)",
+		       pmsg->seq,pmsg->dsize,call->app_ready_qty);
+
+		call->app_ready_seq = pmsg->seq;
+		call->app_ready_qty += pmsg->dsize;
+		list_del_init(&pmsg->link);
+		list_add_tail(&pmsg->link,&call->app_readyq);
+	}
+
+	/* see if we've got the last packet yet */
+	if (!list_empty(&call->app_readyq)) {
+		pmsg = list_entry(call->app_readyq.prev,struct rxrpc_message,link);
+		if (pmsg->hdr.flags & RXRPC_LAST_PACKET) {
+			call->app_last_rcv = 1;
+			_debug("Last packet on readyq");
+		}
+	}
+
+	switch (call->app_call_state) {
+		/* do nothing if call already aborted */
+	case RXRPC_CSTATE_ERROR:
+		spin_unlock(&call->lock);
+		_leave(" [error]");
+		return;
+
+		/* extract the operation ID from an incoming call if that's not yet been done */
+	case RXRPC_CSTATE_SRVR_RCV_OPID:
+		spin_unlock(&call->lock);
+
+		/* handle as yet insufficient data for the operation ID */
+		if (call->app_ready_qty<4) {
+			if (call->app_last_rcv)
+				rxrpc_call_abort(call,-EINVAL); /* trouble - last packet seen */
+
+			_leave("");
+			return;
+		}
+
+		/* pull the operation ID out of the buffer */
+		ret = rxrpc_call_read_data(call,&opid,sizeof(opid),0);
+		if (ret<0) {
+			printk("Unexpected error from read-data: %d\n",ret);
+			if (call->app_call_state!=RXRPC_CSTATE_ERROR)
+				rxrpc_call_abort(call,ret);
+			_leave("");
+			return;
+		}
+		call->app_opcode = ntohl(opid);
+
+		/* locate the operation in the available ops table */
+		optbl = call->conn->service->ops_begin;
+		lo = 0;
+		hi = call->conn->service->ops_end - optbl;
+
+		while (lo<hi) {
+			int mid = (hi+lo) / 2;
+			op = &optbl[mid];
+			if (call->app_opcode==op->id)
+				goto found_op;
+			if (call->app_opcode>op->id)
+				lo = mid+1;
+			else
+				hi = mid;
+		}
+
+		/* search failed */
+		kproto("Rx Client requested operation %d from %s service",
+		       call->app_opcode,call->conn->service->name);
+		rxrpc_call_abort(call,-EINVAL);
+		_leave(" [inval]");
+		return;
+
+	found_op:
+		_proto("Rx Client requested operation %s from %s service",
+		       op->name,call->conn->service->name);
+
+		/* we're now waiting for the argument block (unless the call was aborted) */
+		spin_lock(&call->lock);
+		if (call->app_call_state==RXRPC_CSTATE_SRVR_RCV_OPID ||
+		    call->app_call_state==RXRPC_CSTATE_SRVR_SND_REPLY) {
+			if (!call->app_last_rcv)
+				call->app_call_state = RXRPC_CSTATE_SRVR_RCV_ARGS;
+			else if (call->app_ready_qty>0)
+				call->app_call_state = RXRPC_CSTATE_SRVR_GOT_ARGS;
+			else
+				call->app_call_state = RXRPC_CSTATE_SRVR_SND_REPLY;
+			call->app_mark = op->asize;
+			call->app_user = op->user;
+		}
+		spin_unlock(&call->lock);
+
+		_state(call);
+		break;
+
+	case RXRPC_CSTATE_SRVR_RCV_ARGS:
+		/* change state if just received last packet of arg block */
+		if (call->app_last_rcv)
+			call->app_call_state = RXRPC_CSTATE_SRVR_GOT_ARGS;
+		spin_unlock(&call->lock);
+
+		_state(call);
+		break;
+
+	case RXRPC_CSTATE_CLNT_RCV_REPLY:
+		/* change state if just received last packet of reply block */
+		rmtimo = 0;
+		if (call->app_last_rcv) {
+			call->app_call_state = RXRPC_CSTATE_CLNT_GOT_REPLY;
+			rmtimo = 1;
+		}
+		spin_unlock(&call->lock);
+
+		if (rmtimo) {
+			del_timer_sync(&call->acks_timeout);
+			del_timer_sync(&call->rcv_timeout);
+			del_timer_sync(&call->ackr_dfr_timo);
+		}
+
+		_state(call);
+		break;
+
+	default:
+		/* deal with data reception in an unexpected state */
+		printk("Unexpected state [[[ %u ]]]\n",call->app_call_state);
+		__rxrpc_call_abort(call,-EBADMSG);
+		_leave("");
+		return;
+	}
+
+	if (call->app_call_state==RXRPC_CSTATE_CLNT_RCV_REPLY && call->app_last_rcv)
+		BUG();
+
+	/* otherwise just invoke the data function whenever we can satisfy its desire for more
+	 * data
+	 */
+	_proto("Rx Received Op Data: st=%u qty=%u mk=%u%s",
+	       call->app_call_state,call->app_ready_qty,call->app_mark,
+	       call->app_last_rcv ? " last-rcvd" : "");
+
+	spin_lock(&call->lock);
+
+	ret = __rxrpc_call_read_data(call);
+	switch (ret) {
+	case 0:
+		spin_unlock(&call->lock);
+		call->app_attn_func(call);
+		break;
+	case -EAGAIN:
+		spin_unlock(&call->lock);
+		break;
+	case -ECONNABORTED:
+		spin_unlock(&call->lock);
+		break;
+	default:			
+		__rxrpc_call_abort(call,ret);
+		break;
+	}
+
+	_state(call);
+
+	_leave("");
+
+} /* end rxrpc_call_receive_data_packet() */
+
+/*****************************************************************************/
+/*
+ * received an ACK packet
+ */
+static void rxrpc_call_receive_ack_packet(struct rxrpc_call *call, struct rxrpc_message *msg)
+{
+	struct rxrpc_ackpacket ack;
+	rxrpc_serial_t serial;
+	rxrpc_seq_t seq;
+	int ret;
+
+	_enter("%p{%u},%p{%u}",call,ntohl(call->call_id),msg,msg->seq);
+
+	/* extract the basic ACK record */
+	if (skb_copy_bits(msg->pkt,msg->offset,&ack,sizeof(ack))<0) {
+		printk("Rx Received short ACK packet\n");
+		return;
+	}
+	msg->offset += sizeof(ack);
+
+	serial = ack.serial;
+	seq = ntohl(ack.firstPacket);
+
+	_proto("Rx Received ACK %%%d { b=%hu m=%hu f=%u p=%u s=%u r=%s n=%u }",
+	       ntohl(msg->hdr.serial),
+	       ntohs(ack.bufferSpace),
+	       ntohs(ack.maxSkew),
+	       seq,
+	       ntohl(ack.previousPacket),
+	       ntohl(serial),
+	       rxrpc_acks[ack.reason],
+	       call->ackr.nAcks
+	       );
+
+	/* check the other side isn't ACK'ing a sequence number I haven't sent yet */
+	if (ack.nAcks>0 && (seq > call->snd_seq_count || seq+ack.nAcks-1 > call->snd_seq_count)) {
+		printk("Received ACK (#%u-#%u) for unsent packet\n",seq,seq+ack.nAcks-1);
+		rxrpc_call_abort(call,-EINVAL);
+		_leave("");
+		return;
+	}
+
+	/* deal with RTT calculation */
+	if (serial) {
+		struct rxrpc_message *rttmsg;
+
+		/* find the prompting packet */
+		spin_lock(&call->lock);
+		if (call->snd_ping && call->snd_ping->hdr.serial==serial) {
+			/* it was a ping packet */
+			rttmsg = call->snd_ping;
+			call->snd_ping = NULL;
+			spin_unlock(&call->lock);
+
+			if (rttmsg) {
+				rttmsg->rttdone = 1;
+				rxrpc_peer_calculate_rtt(call->conn->peer,rttmsg,msg);
+				rxrpc_put_message(rttmsg);
+			}
+		}
+		else {
+			struct list_head *_p;
+
+			/* it ought to be a data packet - look in the pending ACK list */
+			list_for_each(_p,&call->acks_pendq) {
+				rttmsg = list_entry(_p,struct rxrpc_message,link);
+				if (rttmsg->hdr.serial==serial) {
+					if (rttmsg->rttdone)
+						break; /* never do RTT twice without resending */
+
+					rttmsg->rttdone = 1;
+					rxrpc_peer_calculate_rtt(call->conn->peer,rttmsg,msg);
+					break;
+				}
+			}
+			spin_unlock(&call->lock);
+		}
+	}
+
+	switch (ack.reason) {
+		/* deal with negative/positive acknowledgement of data packets */
+	case RXRPC_ACK_REQUESTED:
+	case RXRPC_ACK_DELAY:
+	case RXRPC_ACK_IDLE:
+		rxrpc_call_definitively_ACK(call,seq-1);
+
+	case RXRPC_ACK_DUPLICATE:
+	case RXRPC_ACK_OUT_OF_SEQUENCE:
+	case RXRPC_ACK_EXCEEDS_WINDOW:
+		call->snd_resend_cnt = 0;
+		ret = rxrpc_call_record_ACK(call,msg,seq,ack.nAcks);
+		if (ret<0)
+			rxrpc_call_abort(call,ret);
+		break;
+
+		/* respond to ping packets immediately */
+	case RXRPC_ACK_PING:
+		rxrpc_call_generate_ACK(call,&msg->hdr,&ack);
+		break;
+
+		/* only record RTT on ping response packets */
+	case RXRPC_ACK_PING_RESPONSE:
+		if (call->snd_ping) {
+			struct rxrpc_message *rttmsg;
+
+			/* only do RTT stuff if the response matches the retained ping */
+			rttmsg = NULL;
+			spin_lock(&call->lock);
+			if (call->snd_ping && call->snd_ping->hdr.serial==ack.serial) {
+				rttmsg = call->snd_ping;
+				call->snd_ping = NULL;
+			}
+			spin_unlock(&call->lock);
+
+			if (rttmsg) {
+				rttmsg->rttdone = 1;
+				rxrpc_peer_calculate_rtt(call->conn->peer,rttmsg,msg);
+				rxrpc_put_message(rttmsg);
+			}
+		}
+		break;
+
+	default:
+		printk("Unsupported ACK reason %u\n",ack.reason);
+		break;
+	}
+
+	_leave("");
+} /* end rxrpc_call_receive_ack_packet() */
+
+/*****************************************************************************/
+/*
+ * record definitive ACKs for all messages up to and including the one with the 'highest' seq
+ */
+static void rxrpc_call_definitively_ACK(struct rxrpc_call *call, rxrpc_seq_t highest)
+{
+	struct rxrpc_message *msg;
+	int now_complete;
+
+	_enter("%p{ads=%u},%u",call,call->acks_dftv_seq,highest);
+
+	while (call->acks_dftv_seq<highest) {
+		call->acks_dftv_seq++;
+
+		_proto("Definitive ACK on packet #%u",call->acks_dftv_seq);
+
+		/* discard those at front of queue until message with highest ACK is found */
+		spin_lock(&call->lock);
+		msg = NULL;
+		if (!list_empty(&call->acks_pendq)) {
+			msg = list_entry(call->acks_pendq.next,struct rxrpc_message,link);
+			list_del_init(&msg->link); /* dequeue */
+			if (msg->state==RXRPC_MSG_SENT)
+				call->acks_pend_cnt--;
+		}
+		spin_unlock(&call->lock);
+
+		/* insanity check */
+		if (!msg)
+			panic("%s(): acks_pendq unexpectedly empty\n",__FUNCTION__);
+
+		if (msg->seq!=call->acks_dftv_seq)
+			panic("%s(): Packet #%u expected at front of acks_pendq (#%u found)\n",
+			      __FUNCTION__,call->acks_dftv_seq,msg->seq);
+
+		/* discard the message */
+		msg->state = RXRPC_MSG_DONE;
+		rxrpc_put_message(msg);
+	}
+
+	/* if all sent packets are definitively ACK'd then prod any sleepers just in case */
+	now_complete = 0;
+	spin_lock(&call->lock);
+	if (call->acks_dftv_seq==call->snd_seq_count) {
+		if (call->app_call_state!=RXRPC_CSTATE_COMPLETE) {
+			call->app_call_state = RXRPC_CSTATE_COMPLETE;
+			_state(call);
+			now_complete = 1;
+		}
+	}
+	spin_unlock(&call->lock);
+
+	if (now_complete) {
+		del_timer_sync(&call->acks_timeout);
+		del_timer_sync(&call->rcv_timeout);
+		del_timer_sync(&call->ackr_dfr_timo);
+		call->app_attn_func(call);
+	}
+
+	_leave("");
+} /* end rxrpc_call_definitively_ACK() */
+
+/*****************************************************************************/
+/*
+ * record the specified amount of ACKs/NAKs
+ */
+static int rxrpc_call_record_ACK(struct rxrpc_call *call,
+				 struct rxrpc_message *msg,
+				 rxrpc_seq_t seq,
+				 size_t count)
+{
+	struct rxrpc_message *dmsg;
+	struct list_head *_p;
+	rxrpc_seq_t highest;
+	unsigned ix;
+	size_t chunk;
+	char resend, now_complete;
+	u8 acks[16];
+
+	_enter("%p{apc=%u ads=%u},%p,%u,%u",
+	       call,call->acks_pend_cnt,call->acks_dftv_seq,msg,seq,count);
+
+	/* handle re-ACK'ing of definitively ACK'd packets (may be out-of-order ACKs) */
+	if (seq<=call->acks_dftv_seq) {
+		unsigned delta = call->acks_dftv_seq - seq;
+
+		if (count<=delta) {
+			_leave(" = 0 [all definitively ACK'd]");
+			return 0;
+		}
+
+		seq += delta;
+		count -= delta;
+		msg->offset += delta;
+	}
+
+	highest = seq + count - 1;
+	resend = 0;
+	while (count>0) {
+		/* extract up to 16 ACK slots at a time */
+		chunk = min(count,sizeof(acks));
+		count -= chunk;
+
+		memset(acks,2,sizeof(acks));
+
+		if (skb_copy_bits(msg->pkt,msg->offset,&acks,chunk)<0) {
+			printk("Rx Received short ACK packet\n");
+			_leave(" = -EINVAL");
+			return -EINVAL;
+		}
+		msg->offset += chunk;
+
+		/* check that the ACK set is valid */
+		for (ix=0; ix<chunk; ix++) {
+			switch (acks[ix]) {
+			case RXRPC_ACK_TYPE_ACK:
+				break;
+			case RXRPC_ACK_TYPE_NACK:
+				resend = 1;
+				break;
+			default:
+				printk("Rx Received unsupported ACK state %u\n",acks[ix]);
+				_leave(" = -EINVAL");
+				return -EINVAL;
+			}
+		}
+
+		_proto("Rx ACK of packets #%u-#%u [%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c%c] (pend=%u)",
+		       seq,seq+chunk-1,
+		       _acktype[acks[0x0]],
+		       _acktype[acks[0x1]],
+		       _acktype[acks[0x2]],
+		       _acktype[acks[0x3]],
+		       _acktype[acks[0x4]],
+		       _acktype[acks[0x5]],
+		       _acktype[acks[0x6]],
+		       _acktype[acks[0x7]],
+		       _acktype[acks[0x8]],
+		       _acktype[acks[0x9]],
+		       _acktype[acks[0xA]],
+		       _acktype[acks[0xB]],
+		       _acktype[acks[0xC]],
+		       _acktype[acks[0xD]],
+		       _acktype[acks[0xE]],
+		       _acktype[acks[0xF]],
+		       call->acks_pend_cnt
+		       );
+
+		/* mark the packets in the ACK queue as being provisionally ACK'd */
+		ix = 0;
+		spin_lock(&call->lock);
+
+		/* find the first packet ACK'd/NAK'd here */
+		list_for_each(_p,&call->acks_pendq) {
+			dmsg = list_entry(_p,struct rxrpc_message,link);
+			if (dmsg->seq==seq)
+				goto found_first;
+			_debug("- %u: skipping #%u",ix,dmsg->seq);
+		}
+		goto bad_queue;
+
+	found_first:
+		do {
+			_debug("- %u: processing #%u (%c) apc=%u",
+			       ix,dmsg->seq,_acktype[acks[ix]],call->acks_pend_cnt);
+
+			if (acks[ix]==RXRPC_ACK_TYPE_ACK) {
+				if (dmsg->state==RXRPC_MSG_SENT) call->acks_pend_cnt--;
+				dmsg->state = RXRPC_MSG_ACKED;
+			}
+			else {
+				if (dmsg->state==RXRPC_MSG_ACKED) call->acks_pend_cnt++;
+				dmsg->state = RXRPC_MSG_SENT;
+			}
+			ix++;
+			seq++;
+
+			_p = dmsg->link.next;
+			dmsg = list_entry(_p,struct rxrpc_message,link);
+		} while(ix<chunk && _p!=&call->acks_pendq && dmsg->seq==seq);
+
+		if (ix<chunk)
+			goto bad_queue;
+
+		spin_unlock(&call->lock);
+	}
+
+	if (resend)
+		rxrpc_call_resend(call,highest);
+
+	/* if all packets are provisionally ACK'd, then wake up anyone who's waiting for that */
+	now_complete = 0;
+	spin_lock(&call->lock);
+	if (call->acks_pend_cnt==0) {
+		if (call->app_call_state==RXRPC_CSTATE_SRVR_RCV_FINAL_ACK) {
+			call->app_call_state = RXRPC_CSTATE_COMPLETE;
+			_state(call);
+		}
+		now_complete = 1;
+	}
+	spin_unlock(&call->lock);
+
+	if (now_complete) {
+		_debug("- wake up waiters");
+		del_timer_sync(&call->acks_timeout);
+		del_timer_sync(&call->rcv_timeout);
+		del_timer_sync(&call->ackr_dfr_timo);
+		call->app_attn_func(call);
+	}
+
+	_leave(" = 0 (apc=%u)",call->acks_pend_cnt);
+	return 0;
+
+ bad_queue:
+	panic("%s(): acks_pendq in bad state (packet #%u absent)\n",__FUNCTION__,seq);
+
+} /* end rxrpc_call_record_ACK() */
+
+/*****************************************************************************/
+/*
+ * transfer data from the ready packet queue to the asynchronous read buffer
+ * - since this func is the only one going to look at packets queued on app_readyq, we don't need
+ *   a lock to modify or access them, only to modify the queue pointers
+ * - called with call->lock held
+ * - the buffer must be in kernel space
+ * - returns:
+ *	0 if buffer filled
+ *	-EAGAIN if buffer not filled and more data to come
+ *	-EBADMSG if last packet received and insufficient data left
+ *	-ECONNABORTED if the call has in an error state
+ */
+static int __rxrpc_call_read_data(struct rxrpc_call *call)
+{
+	struct rxrpc_message *msg;
+	size_t qty;
+	int ret;
+
+	_enter("%p{as=%d buf=%p qty=%u/%u}",
+	       call,call->app_async_read,call->app_read_buf,call->app_ready_qty,call->app_mark);
+
+	/* check the state */
+	switch (call->app_call_state) {
+	case RXRPC_CSTATE_SRVR_RCV_ARGS:
+	case RXRPC_CSTATE_CLNT_RCV_REPLY:
+		if (call->app_last_rcv) {
+			printk("%s(%p,%p,%d): Inconsistent call state (%s, last pkt)",
+			      __FUNCTION__,call,call->app_read_buf,call->app_mark,
+			      rxrpc_call_states[call->app_call_state]);
+			BUG();
+		}
+		break;
+
+	case RXRPC_CSTATE_SRVR_RCV_OPID:
+	case RXRPC_CSTATE_SRVR_GOT_ARGS:
+	case RXRPC_CSTATE_CLNT_GOT_REPLY:
+		break;
+
+	case RXRPC_CSTATE_SRVR_SND_REPLY:
+		if (!call->app_last_rcv) {
+			printk("%s(%p,%p,%d): Inconsistent call state (%s, not last pkt)",
+			      __FUNCTION__,call,call->app_read_buf,call->app_mark,
+			      rxrpc_call_states[call->app_call_state]);
+			BUG();
+		}
+		_debug("Trying to read data from call in SND_REPLY state");
+		break;
+
+	case RXRPC_CSTATE_ERROR:
+		_leave(" = -ECONNABORTED");
+		return -ECONNABORTED;
+
+	default:
+		printk("reading in unexpected state [[[ %u ]]]\n",call->app_call_state);
+		BUG();
+	}
+
+	/* handle the case of not having an async buffer */
+	if (!call->app_async_read) {
+		if (call->app_mark==RXRPC_APP_MARK_EOF) {
+			ret = call->app_last_rcv ? 0 : -EAGAIN;
+		}
+		else {
+			if (call->app_mark >= call->app_ready_qty) {
+				call->app_mark = RXRPC_APP_MARK_EOF;
+				ret = 0;
+			}
+			else {
+				ret = call->app_last_rcv ? -EBADMSG : -EAGAIN;
+			}
+		}
+
+		_leave(" = %d [no buf]",ret);
+		return 0;
+	}
+
+	while (!list_empty(&call->app_readyq) && call->app_mark>0) {
+		msg = list_entry(call->app_readyq.next,struct rxrpc_message,link);
+
+		/* drag as much data as we need out of this packet */
+		qty = min(call->app_mark,msg->dsize);
+
+		_debug("reading %u from skb=%p off=%lu",qty,msg->pkt,msg->offset);
+
+		if (call->app_read_buf)
+			if (skb_copy_bits(msg->pkt,msg->offset,call->app_read_buf,qty)<0)
+				panic("%s: Failed to copy data from packet: (%p,%p,%d)",
+				      __FUNCTION__,call,call->app_read_buf,qty);
+
+		/* if that packet is now empty, discard it */
+		call->app_ready_qty -= qty;
+		msg->dsize -= qty;
+
+		if (msg->dsize==0) {
+			list_del_init(&msg->link);
+			rxrpc_put_message(msg);
+		}
+		else {
+			msg->offset += qty;
+		}
+
+		call->app_mark -= qty;
+		if (call->app_read_buf) call->app_read_buf += qty;
+	}
+
+	if (call->app_mark==0) {
+		call->app_async_read = 0;
+		call->app_mark = RXRPC_APP_MARK_EOF;
+		call->app_read_buf = NULL;
+
+		/* adjust the state if used up all packets */
+		if (list_empty(&call->app_readyq) && call->app_last_rcv) {
+			switch (call->app_call_state) {
+			case RXRPC_CSTATE_SRVR_RCV_OPID:
+				call->app_call_state = RXRPC_CSTATE_SRVR_SND_REPLY;
+				call->app_mark = RXRPC_APP_MARK_EOF;
+				_state(call);
+				del_timer_sync(&call->rcv_timeout);
+				break;
+			case RXRPC_CSTATE_SRVR_GOT_ARGS:
+				call->app_call_state = RXRPC_CSTATE_SRVR_SND_REPLY;
+				_state(call);
+				del_timer_sync(&call->rcv_timeout);
+				break;
+			default:
+				call->app_call_state = RXRPC_CSTATE_COMPLETE;
+				_state(call);
+				del_timer_sync(&call->acks_timeout);
+				del_timer_sync(&call->ackr_dfr_timo);
+				del_timer_sync(&call->rcv_timeout);
+				break;
+			}
+		}
+
+		_leave(" = 0");
+		return 0;
+	}
+
+	if (call->app_last_rcv) {
+		_debug("Insufficient data (%u/%u)",call->app_ready_qty,call->app_mark);
+		call->app_async_read = 0;
+		call->app_mark = RXRPC_APP_MARK_EOF;
+		call->app_read_buf = NULL;
+
+		_leave(" = -EBADMSG");
+		return -EBADMSG;
+	}
+
+	_leave(" = -EAGAIN");
+	return -EAGAIN;
+} /* end __rxrpc_call_read_data() */
+
+/*****************************************************************************/
+/*
+ * attempt to read the specified amount of data from the call's ready queue into the buffer
+ * provided
+ * - since this func is the only one going to look at packets queued on app_readyq, we don't need
+ *   a lock to modify or access them, only to modify the queue pointers
+ * - if the buffer pointer is NULL, then data is merely drained, not copied
+ * - if flags&RXRPC_CALL_READ_BLOCK, then the function will wait until there is enough data or an
+ *   error will be generated
+ *   - note that the caller must have added the calling task to the call's wait queue beforehand
+ * - if flags&RXRPC_CALL_READ_ALL, then an error will be generated if this function doesn't read
+ *   all available data
+ */
+int rxrpc_call_read_data(struct rxrpc_call *call, void *buffer, size_t size, int flags)
+{
+	int ret;
+
+	_enter("%p{arq=%u},%p,%d,%x",call,call->app_ready_qty,buffer,size,flags);
+
+	spin_lock(&call->lock);
+
+	if (unlikely(!!call->app_read_buf)) {
+		spin_unlock(&call->lock);
+		_leave(" = -EBUSY");
+		return -EBUSY;
+	}
+
+	call->app_mark = size;
+	call->app_read_buf = buffer;
+	call->app_async_read = 1;
+	call->app_read_count++;
+
+	/* read as much data as possible */
+	ret = __rxrpc_call_read_data(call);
+	switch (ret) {
+	case 0:
+		if (flags&RXRPC_CALL_READ_ALL && (!call->app_last_rcv || call->app_ready_qty>0)) {
+			_leave(" = -EBADMSG");
+			__rxrpc_call_abort(call,-EBADMSG);
+			return -EBADMSG;
+		}
+
+		spin_unlock(&call->lock);
+		call->app_attn_func(call);
+		_leave(" = 0");
+		return ret;
+
+	case -ECONNABORTED:
+		spin_unlock(&call->lock);
+		_leave(" = %d [aborted]",ret);
+		return ret;
+
+	default:			
+		__rxrpc_call_abort(call,ret);
+		_leave(" = %d",ret);
+		return ret;
+
+	case -EAGAIN:
+		spin_unlock(&call->lock);
+
+		if (!(flags&RXRPC_CALL_READ_BLOCK)) {
+			_leave(" = -EAGAIN");
+			return -EAGAIN;
+		}
+
+		/* wait for the data to arrive */
+		_debug("blocking for data arrival");
+
+		for (;;) {
+			set_current_state(TASK_INTERRUPTIBLE);
+			if (!call->app_async_read || signal_pending(current))
+				break;
+			schedule();
+		}
+		set_current_state(TASK_RUNNING);
+
+		if (signal_pending(current)) {
+			_leave(" = -EINTR");
+			return -EINTR;
+		}
+
+		if (call->app_call_state==RXRPC_CSTATE_ERROR) {
+			_leave(" = -ECONNABORTED");
+			return -ECONNABORTED;
+		}
+
+		_leave(" = 0");
+		return 0;
+	}
+
+} /* end rxrpc_call_read_data() */
+
+/*****************************************************************************/
+/*
+ * write data to a call
+ * - the data may not be sent immediately if it doesn't fill a buffer
+ * - if we can't queue all the data for buffering now, siov[] will have been adjusted to take
+ *   account of what has been sent
+ */
+int rxrpc_call_write_data(struct rxrpc_call *call,
+			  size_t sioc,
+			  struct iovec siov[],
+			  u8 rxhdr_flags,
+			  int alloc_flags,
+			  int dup_data,
+			  size_t *size_sent)
+{
+	struct rxrpc_message *msg;
+	struct iovec *sptr;
+	size_t space, size, chunk, tmp;
+	char *buf;
+	int ret;
+
+	_enter("%p,%u,%p,%02x,%x,%d,%p",call,sioc,siov,rxhdr_flags,alloc_flags,dup_data,size_sent);
+
+	*size_sent = 0;
+	size = 0;
+	ret = -EINVAL;
+
+	/* can't send more if we've sent last packet from this end */
+	switch (call->app_call_state) {
+	case RXRPC_CSTATE_SRVR_SND_REPLY:
+	case RXRPC_CSTATE_CLNT_SND_ARGS:
+		break;
+	case RXRPC_CSTATE_ERROR:
+		ret = call->app_errno;
+	default:
+		goto out;
+	}
+
+	/* calculate how much data we've been given */
+	sptr = siov;
+	for (; sioc>0; sptr++, sioc--) {
+		if (!sptr->iov_len) continue;
+
+		if (!sptr->iov_base)
+			goto out;
+
+		size += sptr->iov_len;
+	}
+
+	_debug("- size=%u mtu=%u",size,call->conn->mtu_size);
+
+	do {
+		/* make sure there's a message under construction */
+		if (!call->snd_nextmsg) {
+			/* no - allocate a message with no data yet attached */
+			ret = rxrpc_conn_newmsg(call->conn,call,RXRPC_PACKET_TYPE_DATA,
+						0,NULL,alloc_flags,&call->snd_nextmsg);
+			if (ret<0)
+				goto out;
+			_debug("- allocated new message [ds=%u]",call->snd_nextmsg->dsize);
+		}
+
+		msg = call->snd_nextmsg;
+		msg->hdr.flags |= rxhdr_flags;
+
+		/* deal with zero-length terminal packet */
+		if (size==0) {
+			if (rxhdr_flags & RXRPC_LAST_PACKET) {
+				ret = rxrpc_call_flush(call);
+				if (ret<0)
+					goto out;
+			}
+			break;
+		}
+
+		/* work out how much space current packet has available */
+		space = call->conn->mtu_size - msg->dsize;
+		chunk = min(space,size);
+
+		_debug("- [before] space=%u chunk=%u",space,chunk);
+
+		while (!siov->iov_len)
+			siov++;
+
+		/* if we are going to have to duplicate the data then coalesce it too */
+		if (dup_data) {
+			/* don't allocate more that 1 page at a time */
+			if (chunk>PAGE_SIZE)
+				chunk = PAGE_SIZE;
+
+			/* allocate a data buffer and attach to the message */
+			buf = kmalloc(chunk,alloc_flags);
+			if (unlikely(!buf)) {
+				if (msg->dsize==sizeof(struct rxrpc_header)) {
+					/* discard an empty msg and wind back the seq counter */
+					rxrpc_put_message(msg);
+					call->snd_nextmsg = NULL;
+					call->snd_seq_count--;
+				}
+
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			tmp = msg->dcount++;
+			set_bit(tmp,&msg->dfree);
+			msg->data[tmp].iov_base = buf;
+			msg->data[tmp].iov_len = chunk;
+			msg->dsize += chunk;
+			*size_sent += chunk;
+			size -= chunk;
+
+			/* load the buffer with data */
+			while (chunk>0) {
+				tmp = min(chunk,siov->iov_len);
+				memcpy(buf,siov->iov_base,tmp);
+				buf += tmp;
+				siov->iov_base += tmp;
+				siov->iov_len -= tmp;
+				if (!siov->iov_len)
+					siov++;
+				chunk -= tmp;
+			}
+		}
+		else {
+			/* we want to attach the supplied buffers directly */
+			while (chunk>0 && msg->dcount<RXRPC_MSG_MAX_IOCS) {
+				tmp = msg->dcount++;
+				msg->data[tmp].iov_base = siov->iov_base;
+				msg->data[tmp].iov_len = siov->iov_len;
+				msg->dsize += siov->iov_len;
+				*size_sent += siov->iov_len;
+				size -= siov->iov_len;
+				chunk -= siov->iov_len;
+				siov++;
+			}
+		}
+
+		_debug("- [loaded] chunk=%u size=%u",chunk,size);
+
+		/* dispatch the message when full, final or requesting ACK */
+		if (msg->dsize>=call->conn->mtu_size || rxhdr_flags) {
+			ret = rxrpc_call_flush(call);
+			if (ret<0)
+				goto out;
+		}
+
+	} while(size>0);
+
+	ret = 0;
+ out:
+	_leave(" = %d (%d queued, %d rem)",ret,*size_sent,size);
+	return ret;
+
+} /* end rxrpc_call_write_data() */
+
+/*****************************************************************************/
+/*
+ * flush outstanding packets to the network
+ */
+int rxrpc_call_flush(struct rxrpc_call *call)
+{
+	struct rxrpc_message *msg;
+	int ret = 0;
+
+	_enter("%p",call);
+
+	rxrpc_get_call(call);
+
+	/* if there's a packet under construction, then dispatch it now */
+	if (call->snd_nextmsg) {
+		msg = call->snd_nextmsg;
+		call->snd_nextmsg = NULL;
+
+		if (msg->hdr.flags & RXRPC_LAST_PACKET) {
+			msg->hdr.flags &= ~RXRPC_MORE_PACKETS;
+			msg->hdr.flags |= RXRPC_REQUEST_ACK;
+		}
+		else {
+			msg->hdr.flags |= RXRPC_MORE_PACKETS;
+		}
+
+		_proto("Sending DATA message { ds=%u dc=%u df=%02lu }",
+		       msg->dsize,msg->dcount,msg->dfree);
+
+		/* queue and adjust call state */
+		spin_lock(&call->lock);
+		list_add_tail(&msg->link,&call->acks_pendq);
+
+		/* decide what to do depending on current state and if this is the last packet */
+		ret = -EINVAL;
+		switch (call->app_call_state) {
+		case RXRPC_CSTATE_SRVR_SND_REPLY:
+			if (msg->hdr.flags & RXRPC_LAST_PACKET) {
+				call->app_call_state = RXRPC_CSTATE_SRVR_RCV_FINAL_ACK;
+				_state(call);
+			}
+			break;
+
+		case RXRPC_CSTATE_CLNT_SND_ARGS:
+			if (msg->hdr.flags & RXRPC_LAST_PACKET) {
+				call->app_call_state = RXRPC_CSTATE_CLNT_RCV_REPLY;
+				_state(call);
+			}
+			break;
+
+		case RXRPC_CSTATE_ERROR:
+			ret = call->app_errno;
+		default:
+			spin_unlock(&call->lock);
+			goto out;
+		}
+
+		call->acks_pend_cnt++;
+
+		mod_timer(&call->acks_timeout,jiffies + rxrpc_call_acks_timeout);
+
+		spin_unlock(&call->lock);
+
+		ret = rxrpc_conn_sendmsg(call->conn,msg);
+		if (ret==0)
+			call->pkt_snd_count++;
+	}
+
+ out:
+	rxrpc_put_call(call);
+
+	_leave(" = %d",ret);
+	return ret;
+
+} /* end rxrpc_call_flush() */
+
+/*****************************************************************************/
+/*
+ * resend NAK'd or unacknowledged packets up to the highest one specified
+ */
+static void rxrpc_call_resend(struct rxrpc_call *call, rxrpc_seq_t highest)
+{
+	struct rxrpc_message *msg;
+	struct list_head *_p;
+	rxrpc_seq_t seq = 0;
+
+	_enter("%p,%u",call,highest);
+
+	_proto("Rx Resend required");
+
+	/* handle too many resends */
+	if (call->snd_resend_cnt>=rxrpc_call_max_resend) {
+		_debug("Aborting due to too many resends (rcv=%d)",call->pkt_rcv_count);
+		rxrpc_call_abort(call,call->pkt_rcv_count>0?-EIO:-ETIMEDOUT);
+		_leave("");
+		return;
+	}
+
+	spin_lock(&call->lock);
+	call->snd_resend_cnt++;
+	for (;;) {
+		/* determine which the next packet we might need to ACK is */
+		if (seq<=call->acks_dftv_seq)
+			seq = call->acks_dftv_seq;
+		seq++;
+
+		if (seq>highest)
+			break;
+
+		/* look for the packet in the pending-ACK queue */
+		list_for_each(_p,&call->acks_pendq) {
+			msg = list_entry(_p,struct rxrpc_message,link);
+			if (msg->seq==seq)
+				goto found_msg;
+		}
+
+		panic("%s(%p,%d): Inconsistent pending-ACK queue (ds=%u sc=%u sq=%u)\n",
+		      __FUNCTION__,call,highest,call->acks_dftv_seq,call->snd_seq_count,seq);
+
+	found_msg:
+		if (msg->state!=RXRPC_MSG_SENT)
+			continue; /* only un-ACK'd packets */
+
+		rxrpc_get_message(msg);
+		spin_unlock(&call->lock);
+
+		/* send each message again (and ignore any errors we might incur) */
+		_proto("Resending DATA message { ds=%u dc=%u df=%02lu }",
+		       msg->dsize,msg->dcount,msg->dfree);
+
+		if (rxrpc_conn_sendmsg(call->conn,msg)==0)
+			call->pkt_snd_count++;
+
+		rxrpc_put_message(msg);
+
+		spin_lock(&call->lock);
+	}
+
+	/* reset the timeout */
+	mod_timer(&call->acks_timeout,jiffies + rxrpc_call_acks_timeout);
+
+	spin_unlock(&call->lock);
+
+	_leave("");
+} /* end rxrpc_call_resend() */
+
+/*****************************************************************************/
+/*
+ * handle an ICMP error being applied to a call
+ */
+void rxrpc_call_handle_error(struct rxrpc_call *call, int local, int errno)
+{
+	_enter("%p{%u},%d",call,ntohl(call->call_id),errno);
+
+	/* if this call is already aborted, then just wake up any waiters */
+	if (call->app_call_state==RXRPC_CSTATE_ERROR) {
+		call->app_error_func(call);
+	}
+	else {
+		/* tell the app layer what happened */
+		spin_lock(&call->lock);
+		call->app_call_state = RXRPC_CSTATE_ERROR;
+		_state(call);
+		if (local)
+			call->app_err_state = RXRPC_ESTATE_LOCAL_ERROR;
+		else
+			call->app_err_state = RXRPC_ESTATE_REMOTE_ERROR;
+		call->app_errno = errno;
+		call->app_mark = RXRPC_APP_MARK_EOF;
+		call->app_read_buf = NULL;
+		call->app_async_read = 0;
+
+		/* map the error */
+		call->app_aemap_func(call);
+
+		del_timer_sync(&call->acks_timeout);
+		del_timer_sync(&call->rcv_timeout);
+		del_timer_sync(&call->ackr_dfr_timo);
+
+		spin_unlock(&call->lock);
+
+		call->app_error_func(call);
+	}
+
+	_leave("");
+} /* end rxrpc_call_handle_error() */

net/rxrpc/connection.c

+/* connection.c: Rx connection routines
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <rxrpc/rxrpc.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/peer.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/call.h>
+#include <rxrpc/message.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+#include "internal.h"
+
+__RXACCT_DECL(atomic_t rxrpc_connection_count);
+
+LIST_HEAD(rxrpc_conns);
+DECLARE_RWSEM(rxrpc_conns_sem);
+
+static void __rxrpc_conn_timeout(rxrpc_timer_t *timer)
+{
+	struct rxrpc_connection *conn = list_entry(timer,struct rxrpc_connection,timeout);
+
+	_debug("Rx CONN TIMEOUT [%p{u=%d}]",conn,atomic_read(&conn->usage));
+
+	rxrpc_conn_do_timeout(conn);
+}
+
+static const struct rxrpc_timer_ops rxrpc_conn_timer_ops = {
+	timed_out:	__rxrpc_conn_timeout,
+};
+
+/*****************************************************************************/
+/*
+ * create a new connection record
+ */
+static inline int __rxrpc_create_connection(struct rxrpc_peer *peer,
+					    struct rxrpc_connection **_conn)
+{
+	struct rxrpc_connection *conn;
+
+	_enter("%p",peer);
+
+	/* allocate and initialise a connection record */
+	conn = kmalloc(sizeof(struct rxrpc_connection),GFP_KERNEL);
+	if (!conn) {
+		_leave(" = -ENOMEM");
+		return -ENOMEM;
+	}
+
+	memset(conn,0,sizeof(struct rxrpc_connection));
+	atomic_set(&conn->usage,1);
+
+	INIT_LIST_HEAD(&conn->link);
+	init_waitqueue_head(&conn->chanwait);
+	spin_lock_init(&conn->lock);
+	rxrpc_timer_init(&conn->timeout,&rxrpc_conn_timer_ops);
+
+	do_gettimeofday(&conn->atime);
+	conn->mtu_size = 1024;
+	conn->peer = peer;
+	conn->trans = peer->trans;
+
+	__RXACCT(atomic_inc(&rxrpc_connection_count));
+	*_conn = conn;
+	_leave(" = 0 (%p)",conn);
+
+	return 0;
+} /* end __rxrpc_create_connection() */
+
+/*****************************************************************************/
+/*
+ * create a new connection record for outgoing connections
+ */
+int rxrpc_create_connection(struct rxrpc_transport *trans,
+			    u16 port,
+			    u32 addr,
+			    unsigned short service_id,
+			    void *security,
+			    struct rxrpc_connection **_conn)
+{
+	struct rxrpc_connection *conn;
+	struct rxrpc_peer *peer;
+	int ret;
+
+	_enter("%p{%hu},%u,%hu",trans,trans->port,ntohs(port),service_id);
+
+	/* get a peer record */
+	ret = rxrpc_peer_lookup(trans,addr,&peer);
+	if (ret<0) {
+		_leave(" = %d",ret);
+		return ret;
+	}
+
+	/* allocate and initialise a connection record */
+	ret = __rxrpc_create_connection(peer,&conn);
+	if (ret<0) {
+		rxrpc_put_peer(peer);
+		_leave(" = %d",ret);
+		return ret;
+	}
+
+	/* fill in the specific bits */
+	conn->addr.sin_family	= AF_INET;
+	conn->addr.sin_port	= port;
+	conn->addr.sin_addr.s_addr = addr;
+
+	conn->in_epoch		= rxrpc_epoch;
+	conn->out_epoch		= rxrpc_epoch;
+	conn->in_clientflag	= 0;
+	conn->out_clientflag	= RXRPC_CLIENT_INITIATED;
+	conn->conn_id		= htonl((unsigned) conn & RXRPC_CIDMASK);
+	conn->service_id	= htons(service_id);
+
+	/* attach to peer */
+	conn->peer = peer;
+
+	write_lock(&peer->conn_lock);
+	list_add_tail(&conn->link,&peer->conn_active);
+	atomic_inc(&peer->conn_count);
+	write_unlock(&peer->conn_lock);
+
+	down_write(&rxrpc_conns_sem);
+	list_add_tail(&conn->proc_link,&rxrpc_conns);
+	up_write(&rxrpc_conns_sem);
+
+	*_conn = conn;
+	_leave(" = 0 (%p)",conn);
+
+	return 0;
+} /* end rxrpc_create_connection() */
+
+/*****************************************************************************/
+/*
+ * lookup the connection for an incoming packet
+ * - create a new connection record for unrecorded incoming connections
+ */
+int rxrpc_connection_lookup(struct rxrpc_peer *peer,
+			    struct rxrpc_message *msg,
+			    struct rxrpc_connection **_conn)
+{
+	struct rxrpc_connection *conn, *candidate = NULL;
+	struct list_head *_p;
+	int ret, fresh = 0;
+	u32 x_epoch, x_connid;
+	u16 x_port, x_secix, x_servid;
+	u8 x_clflag;
+
+	_enter("%p{{%hu}},%u,%hu",
+	       peer,peer->trans->port,ntohs(msg->pkt->h.uh->source),ntohs(msg->hdr.serviceId));
+
+	x_port		= msg->pkt->h.uh->source;
+	x_epoch		= msg->hdr.epoch;
+	x_clflag	= msg->hdr.flags & RXRPC_CLIENT_INITIATED;
+	x_connid	= htonl(ntohl(msg->hdr.cid) & RXRPC_CIDMASK);
+	x_servid	= msg->hdr.serviceId;
+	x_secix		= msg->hdr.securityIndex;
+
+	/* [common case] search the transport's active list first */
+	read_lock(&peer->conn_lock);
+	list_for_each(_p,&peer->conn_active) {
+		conn = list_entry(_p,struct rxrpc_connection,link);
+		if (conn->addr.sin_port		== x_port	&&
+		    conn->in_epoch		== x_epoch	&&
+		    conn->conn_id		== x_connid	&&
+		    conn->security_ix		== x_secix	&&
+		    conn->service_id		== x_servid	&& 
+		    conn->in_clientflag		== x_clflag)
+			goto found_active;
+	}
+	read_unlock(&peer->conn_lock);
+
+	/* [uncommon case] not active 
+	 * - create a candidate for a new record if an inbound connection
+	 * - only examine the graveyard for an outbound connection
+	 */
+	if (x_clflag) {
+		ret = __rxrpc_create_connection(peer,&candidate);
+		if (ret<0) {
+			_leave(" = %d",ret);
+			return ret;
+		}
+
+		/* fill in the specifics */
+		candidate->addr.sin_family	= AF_INET;
+		candidate->addr.sin_port	= x_port;
+		candidate->addr.sin_addr.s_addr = msg->pkt->nh.iph->saddr;
+		candidate->in_epoch		= x_epoch;
+		candidate->out_epoch		= x_epoch;
+		candidate->in_clientflag	= RXRPC_CLIENT_INITIATED;
+		candidate->out_clientflag	= 0;
+		candidate->conn_id		= x_connid;
+		candidate->service_id		= x_servid;
+		candidate->security_ix		= x_secix;
+	}
+
+	/* search the active list again, just in case it appeared whilst we were busy */
+	write_lock(&peer->conn_lock);
+	list_for_each(_p,&peer->conn_active) {
+		conn = list_entry(_p,struct rxrpc_connection,link);
+		if (conn->addr.sin_port		== x_port	&&
+		    conn->in_epoch		== x_epoch	&&
+		    conn->conn_id		== x_connid	&&
+		    conn->security_ix		== x_secix	&&
+		    conn->service_id		== x_servid	&& 
+		    conn->in_clientflag		== x_clflag)
+			goto found_active_second_chance;
+	}
+
+	/* search the transport's graveyard list */
+	spin_lock(&peer->conn_gylock);
+	list_for_each(_p,&peer->conn_graveyard) {
+		conn = list_entry(_p,struct rxrpc_connection,link);
+		if (conn->addr.sin_port		== x_port	&&
+		    conn->in_epoch		== x_epoch	&&
+		    conn->conn_id		== x_connid	&&
+		    conn->security_ix		== x_secix	&&
+		    conn->service_id		== x_servid	&& 
+		    conn->in_clientflag		== x_clflag)
+			goto found_in_graveyard;
+	}
+	spin_unlock(&peer->conn_gylock);
+
+	/* outbound connections aren't created here */
+	if (!x_clflag) {
+		write_unlock(&peer->conn_lock);
+		_leave(" = -ENOENT");
+		return -ENOENT;
+	}
+
+	/* we can now add the new candidate to the list */
+	rxrpc_get_peer(peer);
+	conn = candidate;
+	candidate = NULL;
+	atomic_inc(&peer->conn_count);
+	fresh = 1;
+
+ make_active:
+	list_add_tail(&conn->link,&peer->conn_active);
+
+ success_uwfree:
+	write_unlock(&peer->conn_lock);
+
+	if (candidate) {
+		__RXACCT(atomic_dec(&rxrpc_connection_count));
+		kfree(candidate);
+	}
+
+	if (fresh) {
+		down_write(&rxrpc_conns_sem);
+		list_add_tail(&conn->proc_link,&rxrpc_conns);
+		up_write(&rxrpc_conns_sem);
+	}
+
+ success:
+	*_conn = conn;
+	_leave(" = 0 (%p)",conn);
+	return 0;
+
+	/* handle the connection being found in the active list straight off */
+ found_active:
+	rxrpc_get_connection(conn);
+	read_unlock(&peer->conn_lock);
+	goto success;
+
+	/* handle resurrecting a connection from the graveyard */
+ found_in_graveyard:
+	rxrpc_get_peer(peer);
+	rxrpc_get_connection(conn);
+	rxrpc_krxtimod_del_timer(&conn->timeout);
+	list_del_init(&conn->link);
+	spin_unlock(&peer->conn_gylock);
+	goto make_active;
+
+	/* handle finding the connection on the second time through the active list */
+ found_active_second_chance:
+	rxrpc_get_connection(conn);
+	goto success_uwfree;
+
+} /* end rxrpc_connection_lookup() */
+
+/*****************************************************************************/
+/*
+ * finish using a connection record
+ * - it will be transferred to the peer's connection graveyard when refcount reaches 0
+ */
+void rxrpc_put_connection(struct rxrpc_connection *conn)
+{
+	struct rxrpc_peer *peer = conn->peer;
+
+	_enter("%p{u=%d p=%hu}",conn,atomic_read(&conn->usage),ntohs(conn->addr.sin_port));
+
+	/* sanity check */
+	if (atomic_read(&conn->usage)<=0)
+		BUG();
+
+	spin_lock(&peer->conn_gylock);
+	if (likely(!atomic_dec_and_test(&conn->usage))) {
+		spin_unlock(&peer->conn_gylock);
+		_leave("");
+		return;
+	}
+
+	/* move to graveyard queue */
+	list_del(&conn->link);
+	list_add_tail(&conn->link,&peer->conn_graveyard);
+
+	/* discard in 100 secs */
+	rxrpc_krxtimod_add_timer(&conn->timeout,20*HZ);
+
+	spin_unlock(&peer->conn_gylock);
+
+	rxrpc_put_peer(conn->peer);
+
+	_leave(" [killed]");
+} /* end rxrpc_put_connection() */
+
+/*****************************************************************************/
+/*
+ * free a connection record
+ */
+void rxrpc_conn_do_timeout(struct rxrpc_connection *conn)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("%p{u=%d p=%hu}",conn,atomic_read(&conn->usage),ntohs(conn->addr.sin_port));
+
+	peer = conn->peer;
+
+	if (atomic_read(&conn->usage)<0)
+		BUG();
+
+	/* remove from graveyard if still dead */
+	spin_lock(&peer->conn_gylock);
+	if (atomic_read(&conn->usage)==0) {
+		list_del_init(&conn->link);
+	}
+	else {
+		conn = NULL;
+	}
+	spin_unlock(&peer->conn_gylock);
+
+	if (!conn) {
+		_leave("");
+		return; /* resurrected */
+	}
+
+	_debug("--- Destroying Connection %p ---",conn);
+
+	down_write(&rxrpc_conns_sem);
+	list_del(&conn->proc_link);
+	up_write(&rxrpc_conns_sem);
+
+	__RXACCT(atomic_dec(&rxrpc_connection_count));
+	kfree(conn);
+
+	/* if the graveyard is now empty, wake up anyone waiting for that */
+	if (atomic_dec_and_test(&peer->conn_count))
+		wake_up(&peer->conn_gy_waitq);
+
+	_leave(" [destroyed]");
+} /* end rxrpc_conn_do_timeout() */
+
+/*****************************************************************************/
+/*
+ * clear all connection records from a peer endpoint
+ */
+void rxrpc_conn_clearall(struct rxrpc_peer *peer)
+{
+	DECLARE_WAITQUEUE(myself,current);
+
+	struct rxrpc_connection *conn;
+	int err;
+
+	_enter("%p",peer);
+
+	/* there shouldn't be any active conns remaining */
+	if (!list_empty(&peer->conn_active))
+		BUG();
+
+	/* manually timeout all conns in the graveyard */
+	spin_lock(&peer->conn_gylock);
+	while (!list_empty(&peer->conn_graveyard)) {
+		conn = list_entry(peer->conn_graveyard.next,struct rxrpc_connection,link);
+		err = rxrpc_krxtimod_del_timer(&conn->timeout);
+		spin_unlock(&peer->conn_gylock);
+
+		if (err==0)
+			rxrpc_conn_do_timeout(conn);
+
+		spin_lock(&peer->conn_gylock);
+	}
+	spin_unlock(&peer->conn_gylock);
+
+	/* wait for the the conn graveyard to be completely cleared */
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	add_wait_queue(&peer->conn_gy_waitq,&myself);
+
+	while (atomic_read(&peer->conn_count)!=0) {
+		schedule();
+		set_current_state(TASK_UNINTERRUPTIBLE);
+	}
+
+	remove_wait_queue(&peer->conn_gy_waitq,&myself);
+	set_current_state(TASK_RUNNING);
+
+	_leave("");
+
+} /* end rxrpc_conn_clearall() */
+
+/*****************************************************************************/
+/*
+ * allocate and prepare a message for sending out through the transport endpoint
+ */
+int rxrpc_conn_newmsg(struct rxrpc_connection *conn,
+		      struct rxrpc_call *call,
+		      u8 type,
+		      int dcount,
+		      struct iovec diov[],
+		      int alloc_flags,
+		      struct rxrpc_message **_msg)
+{
+	struct rxrpc_message *msg;
+	int loop;
+
+	_enter("%p{%d},%p,%u",conn,ntohs(conn->addr.sin_port),call,type);
+
+	if (dcount>3) {
+		_leave(" = -EINVAL");
+		return -EINVAL;
+	}
+
+	msg = kmalloc(sizeof(struct rxrpc_message),alloc_flags);
+	if (!msg) {
+		_leave(" = -ENOMEM");
+		return -ENOMEM;
+	}
+
+	memset(msg,0,sizeof(*msg));
+	atomic_set(&msg->usage,1);
+
+	INIT_LIST_HEAD(&msg->link);
+
+	msg->state = RXRPC_MSG_PREPARED;
+
+	msg->hdr.epoch		= conn->out_epoch;
+	msg->hdr.cid		= conn->conn_id | (call ? call->chan_ix : 0);
+	msg->hdr.callNumber	= call ? call->call_id : 0;
+	msg->hdr.type		= type;
+	msg->hdr.flags		= conn->out_clientflag;
+	msg->hdr.securityIndex	= conn->security_ix;
+	msg->hdr.serviceId	= conn->service_id;
+
+	/* generate sequence numbers for data packets */
+	if (call) {
+		switch (type) {
+		case RXRPC_PACKET_TYPE_DATA:
+			msg->seq = ++call->snd_seq_count;
+			msg->hdr.seq = htonl(msg->seq);
+			break;
+		case RXRPC_PACKET_TYPE_ACK:
+			/* ACK sequence numbers are complicated. The following may be wrong:
+			 * - jumbo packet ACKs should have a seq number
+			 * - normal ACKs should not
+			 */
+		default:
+			break;
+		}
+	}
+
+	msg->dcount = dcount + 1;
+	msg->dsize = sizeof(msg->hdr);
+	msg->data[0].iov_len = sizeof(msg->hdr);
+	msg->data[0].iov_base = &msg->hdr;
+
+	for (loop=0; loop<dcount; loop++) {
+		msg->dsize += diov[loop].iov_len;
+		msg->data[loop+1].iov_len  = diov[loop].iov_len;
+		msg->data[loop+1].iov_base = diov[loop].iov_base;
+	}
+
+	__RXACCT(atomic_inc(&rxrpc_message_count));
+	*_msg = msg;
+	_leave(" = 0 (%p) #%d",msg,atomic_read(&rxrpc_message_count));
+	return 0;
+} /* end rxrpc_conn_newmsg() */
+
+/*****************************************************************************/
+/*
+ * free a message
+ */
+void __rxrpc_put_message(struct rxrpc_message *msg)
+{
+	int loop;
+
+	_enter("%p #%d",msg,atomic_read(&rxrpc_message_count));
+
+	if (msg->pkt) kfree_skb(msg->pkt);
+	if (msg->conn) rxrpc_put_connection(msg->conn);
+
+	for (loop=0; loop<8; loop++)
+		if (test_bit(loop,&msg->dfree))
+			kfree(msg->data[loop].iov_base);
+
+	__RXACCT(atomic_dec(&rxrpc_message_count));
+	kfree(msg);
+
+	_leave("");
+} /* end __rxrpc_put_message() */
+
+/*****************************************************************************/
+/*
+ * send a message out through the transport endpoint
+ */
+int rxrpc_conn_sendmsg(struct rxrpc_connection *conn, struct rxrpc_message *msg)
+{
+	struct msghdr msghdr;
+	mm_segment_t oldfs;
+	int ret;
+
+	_enter("%p{%d}",conn,ntohs(conn->addr.sin_port));
+
+	/* fill in some fields in the header */
+	spin_lock(&conn->lock);
+	msg->hdr.serial = htonl(++conn->serial_counter);
+	msg->rttdone = 0;
+	spin_unlock(&conn->lock);
+
+	/* set up the message to be transmitted */
+	msghdr.msg_name		= &conn->addr;
+	msghdr.msg_namelen	= sizeof(conn->addr);
+	msghdr.msg_iov		= msg->data;
+	msghdr.msg_iovlen	= msg->dcount;
+	msghdr.msg_control	= NULL;
+	msghdr.msg_controllen	= 0;
+	msghdr.msg_flags	= MSG_CONFIRM|MSG_DONTWAIT;
+
+	_net("Sending message type %d of %d bytes to %08x:%d",
+	     msg->hdr.type,
+	     msg->dsize,
+	     htonl(conn->addr.sin_addr.s_addr),
+	     htons(conn->addr.sin_port));
+
+	/* send the message */
+	oldfs = get_fs();
+	set_fs(KERNEL_DS);
+	ret = sock_sendmsg(conn->trans->socket,&msghdr,msg->dsize);
+	set_fs(oldfs);
+
+	if (ret<0) {
+		msg->state = RXRPC_MSG_ERROR;
+	}
+	else {
+		msg->state = RXRPC_MSG_SENT;
+		ret = 0;
+
+		spin_lock(&conn->lock);
+		do_gettimeofday(&conn->atime);
+		msg->stamp = conn->atime;
+		spin_unlock(&conn->lock);
+	}
+
+	_leave(" = %d",ret);
+
+	return ret;
+} /* end rxrpc_conn_sendmsg() */
+
+/*****************************************************************************/
+/*
+ * deal with a subsequent call packet
+ */
+int rxrpc_conn_receive_call_packet(struct rxrpc_connection *conn,
+				   struct rxrpc_call *call,
+				   struct rxrpc_message *msg)
+{
+	struct rxrpc_message *pmsg;
+	struct list_head *_p;
+	unsigned cix, seq;
+	int ret = 0;
+
+	_enter("%p,%p,%p",conn,call,msg);
+
+	if (!call) {
+		cix = ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK;
+
+		spin_lock(&conn->lock);
+		call = conn->channels[cix];
+
+		if (!call || call->call_id != msg->hdr.callNumber) {
+			spin_unlock(&conn->lock);
+			rxrpc_trans_immediate_abort(conn->trans,msg,-ENOENT);
+			goto out;
+		}
+		else {
+			rxrpc_get_call(call);
+			spin_unlock(&conn->lock);
+		}
+	}
+	else {
+		rxrpc_get_call(call);
+	}
+
+	_proto("Received packet %%%u [%u] on call %hu:%u:%u",
+	       htonl(msg->hdr.serial),
+	       htonl(msg->hdr.seq),
+	       htons(msg->hdr.serviceId),
+	       htonl(conn->conn_id),
+	       htonl(call->call_id));
+
+	call->pkt_rcv_count++;
+
+	if (msg->pkt->dst && msg->pkt->dst->dev)
+		conn->peer->if_mtu = msg->pkt->dst->dev->mtu - msg->pkt->dst->dev->hard_header_len;
+
+	/* queue on the call in seq order */
+	rxrpc_get_message(msg);
+	seq = msg->seq;
+
+	spin_lock(&call->lock);
+	list_for_each(_p,&call->rcv_receiveq) {
+		pmsg = list_entry(_p,struct rxrpc_message,link);
+		if (pmsg->seq>seq)
+			break;
+	}
+	list_add_tail(&msg->link,_p);
+
+	/* reset the activity timeout */
+	call->flags |= RXRPC_CALL_RCV_PKT;
+	mod_timer(&call->rcv_timeout,jiffies + rxrpc_call_rcv_timeout * HZ);
+
+	spin_unlock(&call->lock);
+
+	rxrpc_krxiod_queue_call(call);
+
+	rxrpc_put_call(call);
+ out:
+	_leave(" = %d",ret);
+
+	return ret;
+} /* end rxrpc_conn_receive_call_packet() */
+
+/*****************************************************************************/
+/*
+ * handle an ICMP error being applied to a connection
+ */
+void rxrpc_conn_handle_error(struct rxrpc_connection *conn, int local, int errno)
+{
+	struct rxrpc_call *calls[4];
+	int loop;
+
+	_enter("%p{%d},%d",conn,ntohs(conn->addr.sin_port),errno);
+
+	/* get a ref to all my calls in one go */
+	memset(calls,0,sizeof(calls));
+	spin_lock(&conn->lock);
+
+	for (loop=3; loop>=0; loop--) {
+		if (conn->channels[loop]) {
+			calls[loop] = conn->channels[loop];
+			rxrpc_get_call(calls[loop]);
+		}
+	}
+
+	spin_unlock(&conn->lock);
+
+	/* now kick them all */
+	for (loop=3; loop>=0; loop--) {
+		if (calls[loop]) {
+			rxrpc_call_handle_error(calls[loop],local,errno);
+			rxrpc_put_call(calls[loop]);
+		}
+	}
+
+	_leave("");
+} /* end rxrpc_conn_handle_error() */

net/rxrpc/internal.h

+/* internal.h: internal Rx RPC stuff
+ *
+ * Copyright (c) 2002   David Howells (dhowells@redhat.com).
+ */
+
+#ifndef RXRPC_INTERNAL_H
+#define RXRPC_INTERNAL_H
+
+#include <linux/compiler.h>
+#include <linux/kernel.h>
+
+/*
+ * debug accounting
+ */
+#if 1
+#define __RXACCT_DECL(X) X
+#define __RXACCT(X) do { X; } while(0) 
+#else
+#define __RXACCT_DECL(X)
+#define __RXACCT(X) do { } while(0)
+#endif
+
+__RXACCT_DECL(extern atomic_t rxrpc_transport_count);
+__RXACCT_DECL(extern atomic_t rxrpc_peer_count);
+__RXACCT_DECL(extern atomic_t rxrpc_connection_count);
+__RXACCT_DECL(extern atomic_t rxrpc_call_count);
+__RXACCT_DECL(extern atomic_t rxrpc_message_count);
+
+/*
+ * debug tracing
+ */
+#define kenter(FMT,...)	printk("==> %s("FMT")\n",__FUNCTION__,##__VA_ARGS__)
+#define kleave(FMT,...)	printk("<== %s()"FMT"\n",__FUNCTION__,##__VA_ARGS__)
+#define kdebug(FMT,...)	printk("    "FMT"\n",##__VA_ARGS__)
+#define kproto(FMT,...)	printk("### "FMT"\n",##__VA_ARGS__)
+#define knet(FMT,...)	printk("    "FMT"\n",##__VA_ARGS__)
+
+#if 0
+#define _enter(FMT,...)	kenter(FMT,##__VA_ARGS__)
+#define _leave(FMT,...)	kleave(FMT,##__VA_ARGS__)
+#define _debug(FMT,...)	kdebug(FMT,##__VA_ARGS__)
+#define _proto(FMT,...)	kproto(FMT,##__VA_ARGS__)
+#define _net(FMT,...)	knet(FMT,##__VA_ARGS__)
+#else
+#define _enter(FMT,...)	do { if (rxrpc_ktrace) kenter(FMT,##__VA_ARGS__); } while(0)
+#define _leave(FMT,...)	do { if (rxrpc_ktrace) kleave(FMT,##__VA_ARGS__); } while(0)
+#define _debug(FMT,...)	do { if (rxrpc_kdebug) kdebug(FMT,##__VA_ARGS__); } while(0)
+#define _proto(FMT,...)	do { if (rxrpc_kproto) kproto(FMT,##__VA_ARGS__); } while(0)
+#define _net(FMT,...)	do { if (rxrpc_knet)   knet  (FMT,##__VA_ARGS__); } while(0)
+#endif
+
+static inline void rxrpc_discard_my_signals(void)
+{
+	while (signal_pending(current)) {
+		siginfo_t sinfo;
+
+		spin_lock_irq(&current->sig->siglock);
+		dequeue_signal(&current->blocked,&sinfo);
+		spin_unlock_irq(&current->sig->siglock);
+	}
+}
+
+/*
+ * call.c
+ */
+extern struct list_head rxrpc_calls;
+extern struct rw_semaphore rxrpc_calls_sem;
+
+/*
+ * connection.c
+ */
+extern struct list_head rxrpc_conns;
+extern struct rw_semaphore rxrpc_conns_sem;
+
+extern void rxrpc_conn_do_timeout(struct rxrpc_connection *conn);
+extern void rxrpc_conn_clearall(struct rxrpc_peer *peer);
+
+/*
+ * peer.c
+ */
+extern struct list_head rxrpc_peers;
+extern struct rw_semaphore rxrpc_peers_sem;
+
+extern void rxrpc_peer_calculate_rtt(struct rxrpc_peer *peer,
+				     struct rxrpc_message *msg,
+				     struct rxrpc_message *resp);
+
+extern void rxrpc_peer_clearall(struct rxrpc_transport *trans);
+
+extern void rxrpc_peer_do_timeout(struct rxrpc_peer *peer);
+
+
+/*
+ * proc.c
+ */
+#ifdef CONFIG_PROC_FS
+extern int rxrpc_proc_init(void);
+extern void rxrpc_proc_cleanup(void);
+#endif
+
+/*
+ * transport.c
+ */
+extern struct list_head rxrpc_proc_transports;
+extern struct rw_semaphore rxrpc_proc_transports_sem;
+
+#endif /* RXRPC_INTERNAL_H */

net/rxrpc/krxiod.c

+/* krxiod.c: Rx I/O daemon
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/version.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <rxrpc/krxiod.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/peer.h>
+#include <rxrpc/call.h>
+#include "internal.h"
+
+static DECLARE_WAIT_QUEUE_HEAD(rxrpc_krxiod_sleepq);
+static DECLARE_COMPLETION(rxrpc_krxiod_dead);
+
+static atomic_t rxrpc_krxiod_qcount = ATOMIC_INIT(0);
+
+static LIST_HEAD(rxrpc_krxiod_transportq);
+static spinlock_t rxrpc_krxiod_transportq_lock = SPIN_LOCK_UNLOCKED;
+
+static LIST_HEAD(rxrpc_krxiod_callq);
+static spinlock_t rxrpc_krxiod_callq_lock = SPIN_LOCK_UNLOCKED;
+
+static volatile int rxrpc_krxiod_die;
+
+/*****************************************************************************/
+/*
+ * Rx I/O daemon
+ */
+static int rxrpc_krxiod(void *arg)
+{
+	DECLARE_WAITQUEUE(krxiod,current);
+
+	printk("Started krxiod %d\n",current->pid);
+	strcpy(current->comm,"krxiod");
+
+	daemonize();
+
+	/* only certain signals are of interest */
+	spin_lock_irq(&current->sig->siglock);
+	siginitsetinv(&current->blocked,0);
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,5,3)
+	recalc_sigpending();
+#else
+	recalc_sigpending(current);
+#endif
+	spin_unlock_irq(&current->sig->siglock);
+
+	/* loop around waiting for work to do */
+	do {
+		/* wait for work or to be told to exit */
+		_debug("### Begin Wait");
+		if (!atomic_read(&rxrpc_krxiod_qcount)) {
+			set_current_state(TASK_INTERRUPTIBLE);
+
+			add_wait_queue(&rxrpc_krxiod_sleepq,&krxiod);
+
+			for (;;) {
+				set_current_state(TASK_INTERRUPTIBLE);
+				if (atomic_read(&rxrpc_krxiod_qcount) ||
+				    rxrpc_krxiod_die ||
+				    signal_pending(current))
+					break;
+
+				schedule();
+			}
+
+			remove_wait_queue(&rxrpc_krxiod_sleepq,&krxiod);
+			set_current_state(TASK_RUNNING);
+		}
+		_debug("### End Wait");
+
+		/* do work if been given some to do */
+		_debug("### Begin Work");
+
+		/* see if there's a transport in need of attention */
+		if (!list_empty(&rxrpc_krxiod_transportq)) {
+			struct rxrpc_transport *trans = NULL;
+
+			spin_lock_irq(&rxrpc_krxiod_transportq_lock);
+
+			if (!list_empty(&rxrpc_krxiod_transportq)) {
+				trans = list_entry(rxrpc_krxiod_transportq.next,
+						   struct rxrpc_transport,krxiodq_link);
+				list_del_init(&trans->krxiodq_link);
+				atomic_dec(&rxrpc_krxiod_qcount);
+
+				/* make sure it hasn't gone away and doesn't go away */
+				if (atomic_read(&trans->usage)>0)
+					rxrpc_get_transport(trans);
+				else
+					trans = NULL;
+			}
+
+			spin_unlock_irq(&rxrpc_krxiod_transportq_lock);
+
+			if (trans) {
+				rxrpc_trans_receive_packet(trans);
+				rxrpc_put_transport(trans);
+			}
+		}
+
+		/* see if there's a call in need of attention */
+		if (!list_empty(&rxrpc_krxiod_callq)) {
+			struct rxrpc_call *call = NULL;
+
+			spin_lock_irq(&rxrpc_krxiod_callq_lock);
+
+			if (!list_empty(&rxrpc_krxiod_callq)) {
+				call = list_entry(rxrpc_krxiod_callq.next,
+						   struct rxrpc_call,rcv_krxiodq_lk);
+				list_del_init(&call->rcv_krxiodq_lk);
+				atomic_dec(&rxrpc_krxiod_qcount);
+
+				/* make sure it hasn't gone away and doesn't go away */
+				if (atomic_read(&call->usage)>0) {
+					_debug("@@@ KRXIOD Begin Attend Call %p",call);
+					rxrpc_get_call(call);
+				}
+				else {
+					call = NULL;
+				}
+			}
+
+			spin_unlock_irq(&rxrpc_krxiod_callq_lock);
+
+			if (call) {
+				rxrpc_call_do_stuff(call);
+				rxrpc_put_call(call);
+				_debug("@@@ KRXIOD End Attend Call %p",call);
+			}
+		}
+
+		_debug("### End Work");
+
+                /* discard pending signals */
+		rxrpc_discard_my_signals();
+
+	} while (!rxrpc_krxiod_die);
+
+	/* and that's all */
+	complete_and_exit(&rxrpc_krxiod_dead,0);
+
+} /* end rxrpc_krxiod() */
+
+/*****************************************************************************/
+/*
+ * start up a krxiod daemon
+ */
+int __init rxrpc_krxiod_init(void)
+{
+	return kernel_thread(rxrpc_krxiod,NULL,0);
+
+} /* end rxrpc_krxiod_init() */
+
+/*****************************************************************************/
+/*
+ * kill the krxiod daemon and wait for it to complete
+ */
+void rxrpc_krxiod_kill(void)
+{
+	rxrpc_krxiod_die = 1;
+	wake_up_all(&rxrpc_krxiod_sleepq);
+	wait_for_completion(&rxrpc_krxiod_dead);
+
+} /* end rxrpc_krxiod_kill() */
+
+/*****************************************************************************/
+/*
+ * queue a transport for attention by krxiod
+ */
+void rxrpc_krxiod_queue_transport(struct rxrpc_transport *trans)
+{
+	unsigned long flags;
+
+	_enter("");
+
+	if (list_empty(&trans->krxiodq_link)) {
+		spin_lock_irqsave(&rxrpc_krxiod_transportq_lock,flags);
+
+		if (list_empty(&trans->krxiodq_link)) {
+			if (atomic_read(&trans->usage)>0) {
+				list_add_tail(&trans->krxiodq_link,&rxrpc_krxiod_transportq);
+				atomic_inc(&rxrpc_krxiod_qcount);
+			}
+		}
+
+		spin_unlock_irqrestore(&rxrpc_krxiod_transportq_lock,flags);
+		wake_up_all(&rxrpc_krxiod_sleepq);
+	}
+
+	_leave("");
+
+} /* end rxrpc_krxiod_queue_transport() */
+
+/*****************************************************************************/
+/*
+ * dequeue a transport from krxiod's attention queue
+ */
+void rxrpc_krxiod_dequeue_transport(struct rxrpc_transport *trans)
+{
+	unsigned long flags;
+
+	_enter("");
+
+	spin_lock_irqsave(&rxrpc_krxiod_transportq_lock,flags);
+	if (!list_empty(&trans->krxiodq_link)) {
+		list_del_init(&trans->krxiodq_link);
+		atomic_dec(&rxrpc_krxiod_qcount);
+	}
+	spin_unlock_irqrestore(&rxrpc_krxiod_transportq_lock,flags);
+
+	_leave("");
+
+} /* end rxrpc_krxiod_dequeue_transport() */
+
+/*****************************************************************************/
+/*
+ * queue a call for attention by krxiod
+ */
+void rxrpc_krxiod_queue_call(struct rxrpc_call *call)
+{
+	unsigned long flags;
+
+	if (list_empty(&call->rcv_krxiodq_lk)) {
+		spin_lock_irqsave(&rxrpc_krxiod_callq_lock,flags);
+		if (atomic_read(&call->usage)>0) {
+			list_add_tail(&call->rcv_krxiodq_lk,&rxrpc_krxiod_callq);
+			atomic_inc(&rxrpc_krxiod_qcount);
+		}
+		spin_unlock_irqrestore(&rxrpc_krxiod_callq_lock,flags);
+	}
+	wake_up_all(&rxrpc_krxiod_sleepq);
+	
+} /* end rxrpc_krxiod_queue_call() */
+
+/*****************************************************************************/
+/*
+ * dequeue a call from krxiod's attention queue
+ */
+void rxrpc_krxiod_dequeue_call(struct rxrpc_call *call)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&rxrpc_krxiod_callq_lock,flags);
+	if (!list_empty(&call->rcv_krxiodq_lk)) {
+		list_del_init(&call->rcv_krxiodq_lk);
+		atomic_dec(&rxrpc_krxiod_qcount);
+	}
+	spin_unlock_irqrestore(&rxrpc_krxiod_callq_lock,flags);
+
+} /* end rxrpc_krxiod_dequeue_call() */

net/rxrpc/krxsecd.c

+/* krxsecd.c: Rx security daemon
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * This daemon deals with:
+ * - consulting the application as to whether inbound peers and calls should be authorised
+ * - generating security challenges for inbound connections
+ * - responding to security challenges on outbound connections
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <rxrpc/krxsecd.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/message.h>
+#include <rxrpc/peer.h>
+#include <rxrpc/call.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <net/sock.h>
+#include "internal.h"
+
+static DECLARE_WAIT_QUEUE_HEAD(rxrpc_krxsecd_sleepq);
+static DECLARE_COMPLETION(rxrpc_krxsecd_dead);
+static volatile int rxrpc_krxsecd_die;
+
+static atomic_t rxrpc_krxsecd_qcount;
+
+/* queue of unprocessed inbound messages with seqno #1 and RXRPC_CLIENT_INITIATED flag set */
+static LIST_HEAD(rxrpc_krxsecd_initmsgq);
+static spinlock_t rxrpc_krxsecd_initmsgq_lock = SPIN_LOCK_UNLOCKED;
+
+static void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg);
+
+/*****************************************************************************/
+/*
+ * Rx security daemon
+ */
+static int rxrpc_krxsecd(void *arg)
+{
+	DECLARE_WAITQUEUE(krxsecd,current);
+
+	int die;
+
+	printk("Started krxsecd %d\n",current->pid);
+	strcpy(current->comm,"krxsecd");
+
+	daemonize();
+
+	/* only certain signals are of interest */
+	spin_lock_irq(&current->sig->siglock);
+	siginitsetinv(&current->blocked,0);
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,5,3)
+	recalc_sigpending();
+#else
+	recalc_sigpending(current);
+#endif
+	spin_unlock_irq(&current->sig->siglock);
+
+	/* loop around waiting for work to do */
+	do {
+		/* wait for work or to be told to exit */
+		_debug("### Begin Wait");
+		if (!atomic_read(&rxrpc_krxsecd_qcount)) {
+			set_current_state(TASK_INTERRUPTIBLE);
+
+			add_wait_queue(&rxrpc_krxsecd_sleepq,&krxsecd);
+
+			for (;;) {
+				set_current_state(TASK_INTERRUPTIBLE);
+				if (atomic_read(&rxrpc_krxsecd_qcount) ||
+				    rxrpc_krxsecd_die ||
+				    signal_pending(current))
+					break;
+
+				schedule();
+			}
+
+			remove_wait_queue(&rxrpc_krxsecd_sleepq,&krxsecd);
+			set_current_state(TASK_RUNNING);
+		}
+		die = rxrpc_krxsecd_die;
+		_debug("### End Wait");
+
+		/* see if there're incoming calls in need of authenticating */
+		_debug("### Begin Inbound Calls");
+
+		if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
+			struct rxrpc_message *msg = NULL;
+
+			spin_lock(&rxrpc_krxsecd_initmsgq_lock);
+
+			if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
+				msg = list_entry(rxrpc_krxsecd_initmsgq.next,
+						 struct rxrpc_message,link);
+				list_del_init(&msg->link);
+				atomic_dec(&rxrpc_krxsecd_qcount);
+			}
+
+			spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
+
+			if (msg) {
+				rxrpc_krxsecd_process_incoming_call(msg);
+				rxrpc_put_message(msg);
+			}
+		}
+
+		_debug("### End Inbound Calls");
+
+                /* discard pending signals */
+		rxrpc_discard_my_signals();
+
+	} while (!die);
+
+	/* and that's all */
+	complete_and_exit(&rxrpc_krxsecd_dead,0);
+
+} /* end rxrpc_krxsecd() */
+
+/*****************************************************************************/
+/*
+ * start up a krxsecd daemon
+ */
+int __init rxrpc_krxsecd_init(void)
+{
+	return kernel_thread(rxrpc_krxsecd,NULL,0);
+
+} /* end rxrpc_krxsecd_init() */
+
+/*****************************************************************************/
+/*
+ * kill the krxsecd daemon and wait for it to complete
+ */
+void rxrpc_krxsecd_kill(void)
+{
+	rxrpc_krxsecd_die = 1;
+	wake_up_all(&rxrpc_krxsecd_sleepq);
+	wait_for_completion(&rxrpc_krxsecd_dead);
+
+} /* end rxrpc_krxsecd_kill() */
+
+/*****************************************************************************/
+/*
+ * clear all pending incoming calls for the specified transport
+ */
+void rxrpc_krxsecd_clear_transport(struct rxrpc_transport *trans)
+{
+	LIST_HEAD(tmp);
+
+	struct rxrpc_message *msg;
+	struct list_head *_p, *_n;
+
+	_enter("%p",trans);
+
+	/* move all the messages for this transport onto a temp list */
+	spin_lock(&rxrpc_krxsecd_initmsgq_lock);
+
+	list_for_each_safe(_p,_n,&rxrpc_krxsecd_initmsgq) {
+		msg = list_entry(_p,struct rxrpc_message,link);
+		if (msg->trans==trans) {
+			list_del(&msg->link);
+			list_add_tail(&msg->link,&tmp);
+			atomic_dec(&rxrpc_krxsecd_qcount);
+		}
+	}
+
+	spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
+
+	/* zap all messages on the temp list */
+	while (!list_empty(&tmp)) {
+		msg = list_entry(tmp.next,struct rxrpc_message,link);
+		list_del_init(&msg->link);
+		rxrpc_put_message(msg);
+	}
+
+	_leave("");
+} /* end rxrpc_krxsecd_clear_transport() */
+
+/*****************************************************************************/
+/*
+ * queue a message on the incoming calls list
+ */
+void rxrpc_krxsecd_queue_incoming_call(struct rxrpc_message *msg)
+{
+	_enter("%p",msg);
+
+	/* queue for processing by krxsecd */
+	spin_lock(&rxrpc_krxsecd_initmsgq_lock);
+
+	if (!rxrpc_krxsecd_die) {
+		rxrpc_get_message(msg);
+		list_add_tail(&msg->link,&rxrpc_krxsecd_initmsgq);
+		atomic_inc(&rxrpc_krxsecd_qcount);
+	}
+
+	spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
+
+	wake_up(&rxrpc_krxsecd_sleepq);
+
+	_leave("");
+} /* end rxrpc_krxsecd_queue_incoming_call() */
+
+/*****************************************************************************/
+/*
+ * process the initial message of an incoming call
+ */
+void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg)
+{
+	struct rxrpc_transport *trans = msg->trans;
+	struct rxrpc_service *srv;
+	struct rxrpc_call *call;
+	struct list_head *_p;
+	unsigned short sid;
+	int ret;
+
+	_enter("%p{tr=%p}",msg,trans);
+
+	ret = rxrpc_incoming_call(msg->conn,msg,&call);
+	if (ret<0)
+		goto out;
+
+	/* find the matching service on the transport */
+	sid = ntohs(msg->hdr.serviceId);
+	srv = NULL;
+
+	spin_lock(&trans->lock);
+	list_for_each(_p,&trans->services) {
+		srv = list_entry(_p,struct rxrpc_service,link);
+		if (srv->service_id==sid && try_inc_mod_count(srv->owner)) {
+			/* found a match (made sure it won't vanish) */
+			_debug("found service '%s'",srv->name);
+			call->owner = srv->owner;
+			break;
+		}
+	}
+	spin_unlock(&trans->lock);
+
+	/* report the new connection
+	 * - the func must inc the call's usage count to keep it
+	 */
+	ret = -ENOENT;
+	if (_p!=&trans->services) {
+		/* attempt to accept the call */
+		call->conn->service = srv;
+		call->app_attn_func = srv->attn_func;
+		call->app_error_func = srv->error_func;
+		call->app_aemap_func = srv->aemap_func;
+
+		ret = srv->new_call(call);
+
+		/* send an abort if an error occurred */
+		if (ret<0) {
+			rxrpc_call_abort(call,ret);
+		}
+		else {
+			/* formally receive and ACK the new packet */
+			ret = rxrpc_conn_receive_call_packet(call->conn,call,msg);
+		}
+	}
+
+	rxrpc_put_call(call);
+ out:
+	if (ret<0)
+		rxrpc_trans_immediate_abort(trans,msg,ret);
+
+	_leave(" (%d)",ret);
+} /* end rxrpc_krxsecd_process_incoming_call() */

net/rxrpc/krxtimod.c

+/* krxtimod.c: RXRPC timeout daemon
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/completion.h>
+#include <rxrpc/rxrpc.h>
+#include <rxrpc/krxtimod.h>
+#include <asm/errno.h>
+#include "internal.h"
+
+static DECLARE_COMPLETION(krxtimod_alive);
+static DECLARE_COMPLETION(krxtimod_dead);
+static DECLARE_WAIT_QUEUE_HEAD(krxtimod_sleepq);
+static int krxtimod_die;
+
+static LIST_HEAD(krxtimod_list);
+static spinlock_t krxtimod_lock = SPIN_LOCK_UNLOCKED;
+
+static int krxtimod(void *arg);
+
+/*****************************************************************************/
+/*
+ * start the timeout daemon
+ */
+int rxrpc_krxtimod_start(void)
+{
+	int ret;
+
+	ret = kernel_thread(krxtimod,NULL,0);
+	if (ret<0)
+		return ret;
+
+	wait_for_completion(&krxtimod_alive);
+
+	return ret;
+} /* end rxrpc_krxtimod_start() */
+
+/*****************************************************************************/
+/*
+ * stop the timeout daemon
+ */
+void rxrpc_krxtimod_kill(void)
+{
+	/* get rid of my daemon */
+	krxtimod_die = 1;
+	wake_up(&krxtimod_sleepq);
+	wait_for_completion(&krxtimod_dead);
+
+} /* end rxrpc_krxtimod_kill() */
+
+/*****************************************************************************/
+/*
+ * timeout processing daemon
+ */
+static int krxtimod(void *arg)
+{
+	DECLARE_WAITQUEUE(myself,current);
+
+	rxrpc_timer_t *timer;
+
+	printk("Started krxtimod %d\n",current->pid);
+	strcpy(current->comm,"krxtimod");
+
+	daemonize();
+
+	complete(&krxtimod_alive);
+
+	/* only certain signals are of interest */
+	spin_lock_irq(&current->sig->siglock);
+	siginitsetinv(&current->blocked,0);
+#if LINUX_VERSION_CODE > KERNEL_VERSION(2,5,3)
+	recalc_sigpending();
+#else
+	recalc_sigpending(current);
+#endif
+	spin_unlock_irq(&current->sig->siglock);
+
+	/* loop around looking for things to attend to */
+ loop:
+	set_current_state(TASK_INTERRUPTIBLE);
+	add_wait_queue(&krxtimod_sleepq,&myself);
+
+	for (;;) {
+		unsigned long jif;
+		signed long timeout;
+
+		/* deal with the server being asked to die */
+		if (krxtimod_die) {
+			remove_wait_queue(&krxtimod_sleepq,&myself);
+			_leave("");
+			complete_and_exit(&krxtimod_dead,0);
+		}
+
+		/* discard pending signals */
+		rxrpc_discard_my_signals();
+
+		/* work out the time to elapse before the next event */
+		spin_lock(&krxtimod_lock);
+		if (list_empty(&krxtimod_list)) {
+			timeout = MAX_SCHEDULE_TIMEOUT;
+		}
+		else {
+			timer = list_entry(krxtimod_list.next,rxrpc_timer_t,link);
+			timeout = timer->timo_jif;
+			jif = jiffies;
+
+			if (time_before_eq(timeout,jif))
+				goto immediate;
+
+			else {
+				timeout = (long)timeout - (long)jiffies;
+			}
+		}
+		spin_unlock(&krxtimod_lock);
+
+		schedule_timeout(timeout);
+
+		set_current_state(TASK_INTERRUPTIBLE);
+	}
+
+	/* the thing on the front of the queue needs processing
+	 * - we come here with the lock held and timer pointing to the expired entry
+	 */
+ immediate:
+	remove_wait_queue(&krxtimod_sleepq,&myself);
+	set_current_state(TASK_RUNNING);
+
+	_debug("@@@ Begin Timeout of %p",timer);
+
+	/* dequeue the timer */
+	list_del_init(&timer->link);
+	spin_unlock(&krxtimod_lock);
+
+	/* call the timeout function */
+	timer->ops->timed_out(timer);
+
+	_debug("@@@ End Timeout");
+	goto loop;
+
+} /* end krxtimod() */
+
+/*****************************************************************************/
+/*
+ * (re-)queue a timer
+ */
+void rxrpc_krxtimod_add_timer(rxrpc_timer_t *timer, unsigned long timeout)
+{
+	struct list_head *_p;
+	rxrpc_timer_t *ptimer;
+
+	_enter("%p,%lu",timer,timeout);
+
+	spin_lock(&krxtimod_lock);
+
+	list_del(&timer->link);
+
+	/* the timer was deferred or reset - put it back in the queue at the right place */
+	timer->timo_jif = jiffies + timeout;
+
+	list_for_each(_p,&krxtimod_list) {
+		ptimer = list_entry(_p,rxrpc_timer_t,link);
+		if (time_before(timer->timo_jif,ptimer->timo_jif))
+			break;
+	}
+
+	list_add_tail(&timer->link,_p); /* insert before stopping point */
+
+	spin_unlock(&krxtimod_lock);
+
+	wake_up(&krxtimod_sleepq);
+
+	_leave("");
+} /* end rxrpc_krxtimod_queue_vlocation() */
+
+/*****************************************************************************/
+/*
+ * dequeue a timer
+ * - returns 0 if the timer was deleted or -ENOENT if it wasn't queued
+ */
+int rxrpc_krxtimod_del_timer(rxrpc_timer_t *timer)
+{
+	int ret = 0;
+
+	_enter("%p",timer);
+
+	spin_lock(&krxtimod_lock);
+
+	if (list_empty(&timer->link))
+		ret = -ENOENT;
+	else
+		list_del_init(&timer->link);
+
+	spin_unlock(&krxtimod_lock);
+
+	wake_up(&krxtimod_sleepq);
+
+	_leave(" = %d",ret);
+	return ret;
+} /* end rxrpc_krxtimod_del_timer() */

net/rxrpc/main.c

+/* main.c: Rx RPC interface
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <rxrpc/rxrpc.h>
+#include <rxrpc/krxiod.h>
+#include <rxrpc/krxsecd.h>
+#include <rxrpc/krxtimod.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/call.h>
+#include <rxrpc/message.h>
+#include "internal.h"
+
+static int rxrpc_initialise(void);
+static void rxrpc_cleanup(void);
+
+module_init(rxrpc_initialise);
+module_exit(rxrpc_cleanup);
+
+MODULE_DESCRIPTION("Rx RPC implementation");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL");
+
+u32 rxrpc_epoch;
+
+/*****************************************************************************/
+/*
+ * initialise the Rx module
+ */
+static int rxrpc_initialise(void)
+{
+	int ret;
+
+	/* my epoch value */
+	rxrpc_epoch = htonl(xtime.tv_sec);
+
+	/* register the /proc interface */
+#ifdef CONFIG_PROC_FS
+	ret = rxrpc_proc_init();
+	if (ret<0)
+		return ret;
+#endif
+
+	/* register the sysctl files */
+#ifdef CONFIG_SYSCTL
+	ret = rxrpc_sysctl_init();
+	if (ret<0)
+		goto error_proc;
+#endif
+
+	/* start the krxtimod daemon */
+	ret = rxrpc_krxtimod_start();
+	if (ret<0)
+		goto error_sysctl;
+
+	/* start the krxiod daemon */
+	ret = rxrpc_krxiod_init();
+	if (ret<0)
+		goto error_krxtimod;
+
+	/* start the krxsecd daemon */
+	ret = rxrpc_krxsecd_init();
+	if (ret<0)
+		goto error_krxiod;
+
+	kdebug("\n\n");
+
+	return 0;
+
+ error_krxiod:
+	rxrpc_krxiod_kill();
+ error_krxtimod:
+	rxrpc_krxtimod_kill();
+ error_sysctl:
+#ifdef CONFIG_SYSCTL
+	rxrpc_sysctl_cleanup();
+#endif
+ error_proc:
+#ifdef CONFIG_PROC_FS
+	rxrpc_proc_cleanup();
+#endif
+	return ret;
+} /* end rxrpc_initialise() */
+
+/*****************************************************************************/
+/*
+ * clean up the Rx module
+ */
+static void rxrpc_cleanup(void)
+{
+	kenter("");
+
+	__RXACCT(printk("Outstanding Messages   : %d\n",atomic_read(&rxrpc_message_count)));
+	__RXACCT(printk("Outstanding Calls      : %d\n",atomic_read(&rxrpc_call_count)));
+	__RXACCT(printk("Outstanding Connections: %d\n",atomic_read(&rxrpc_connection_count)));
+	__RXACCT(printk("Outstanding Peers      : %d\n",atomic_read(&rxrpc_peer_count)));
+	__RXACCT(printk("Outstanding Transports : %d\n",atomic_read(&rxrpc_transport_count)));
+
+	rxrpc_krxsecd_kill();
+	rxrpc_krxiod_kill();
+	rxrpc_krxtimod_kill();
+#ifdef CONFIG_SYSCTL
+	rxrpc_sysctl_cleanup();
+#endif
+#ifdef CONFIG_PROC_FS
+	rxrpc_proc_cleanup();
+#endif
+
+	__RXACCT(printk("Outstanding Messages   : %d\n",atomic_read(&rxrpc_message_count)));
+	__RXACCT(printk("Outstanding Calls      : %d\n",atomic_read(&rxrpc_call_count)));
+	__RXACCT(printk("Outstanding Connections: %d\n",atomic_read(&rxrpc_connection_count)));
+	__RXACCT(printk("Outstanding Peers      : %d\n",atomic_read(&rxrpc_peer_count)));
+	__RXACCT(printk("Outstanding Transports : %d\n",atomic_read(&rxrpc_transport_count)));
+
+	kleave();
+} /* end rxrpc_cleanup() */

net/rxrpc/peer.c

+/* peer.c: Rx RPC peer management
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <rxrpc/rxrpc.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/peer.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/call.h>
+#include <rxrpc/message.h>
+#include <linux/udp.h>
+#include <linux/ip.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+#include <asm/div64.h>
+#include "internal.h"
+
+__RXACCT_DECL(atomic_t rxrpc_peer_count);
+LIST_HEAD(rxrpc_peers);
+DECLARE_RWSEM(rxrpc_peers_sem);
+
+static void __rxrpc_peer_timeout(rxrpc_timer_t *timer)
+{
+	struct rxrpc_peer *peer = list_entry(timer,struct rxrpc_peer,timeout);
+
+	_debug("Rx PEER TIMEOUT [%p{u=%d}]",peer,atomic_read(&peer->usage));
+
+	rxrpc_peer_do_timeout(peer);
+}
+
+static const struct rxrpc_timer_ops rxrpc_peer_timer_ops = {
+	.timed_out	= __rxrpc_peer_timeout,
+};
+
+/*****************************************************************************/
+/*
+ * create a peer record
+ */
+static int __rxrpc_create_peer(struct rxrpc_transport *trans, u32 addr, struct rxrpc_peer **_peer)
+{
+	struct rxrpc_peer *peer;
+
+	_enter("%p,%08x",trans,ntohl(addr));
+
+	/* allocate and initialise a peer record */
+	peer = kmalloc(sizeof(struct rxrpc_peer),GFP_KERNEL);
+	if (!peer) {
+		_leave(" = -ENOMEM");
+		return -ENOMEM;
+	}
+
+	memset(peer,0,sizeof(struct rxrpc_peer));
+	atomic_set(&peer->usage,1);
+
+	INIT_LIST_HEAD(&peer->link);
+	INIT_LIST_HEAD(&peer->proc_link);
+	INIT_LIST_HEAD(&peer->conn_active);
+	INIT_LIST_HEAD(&peer->conn_graveyard);
+	spin_lock_init(&peer->conn_gylock);
+	init_waitqueue_head(&peer->conn_gy_waitq);
+	rwlock_init(&peer->conn_lock);
+	atomic_set(&peer->conn_count,0);
+	spin_lock_init(&peer->lock);
+	rxrpc_timer_init(&peer->timeout,&rxrpc_peer_timer_ops);
+
+	peer->addr.s_addr = addr;
+
+	peer->trans = trans;
+	peer->ops = trans->peer_ops;
+
+	__RXACCT(atomic_inc(&rxrpc_peer_count));
+	*_peer = peer;
+	_leave(" = 0 (%p)",peer);
+
+	return 0;
+} /* end __rxrpc_create_peer() */
+
+/*****************************************************************************/
+/*
+ * find a peer record on the specified transport
+ * - returns (if successful) with peer record usage incremented
+ * - resurrects it from the graveyard if found there
+ */
+int rxrpc_peer_lookup(struct rxrpc_transport *trans, u32 addr, struct rxrpc_peer **_peer)
+{
+	struct rxrpc_peer *peer, *candidate = NULL;
+	struct list_head *_p;
+	int ret;
+
+	_enter("%p{%hu},%08x",trans,trans->port,ntohl(addr));
+
+	/* [common case] search the transport's active list first */
+	read_lock(&trans->peer_lock);
+	list_for_each(_p,&trans->peer_active) {
+		peer = list_entry(_p,struct rxrpc_peer,link);
+		if (peer->addr.s_addr==addr)
+			goto found_active;
+	}
+	read_unlock(&trans->peer_lock);
+
+	/* [uncommon case] not active - create a candidate for a new record */
+	ret = __rxrpc_create_peer(trans,addr,&candidate);
+	if (ret<0) {
+		_leave(" = %d",ret);
+		return ret;
+	}
+
+	/* search the active list again, just in case it appeared whilst we were busy */
+	write_lock(&trans->peer_lock);
+	list_for_each(_p,&trans->peer_active) {
+		peer = list_entry(_p,struct rxrpc_peer,link);
+		if (peer->addr.s_addr==addr)
+			goto found_active_second_chance;
+	}
+
+	/* search the transport's graveyard list */
+	spin_lock(&trans->peer_gylock);
+	list_for_each(_p,&trans->peer_graveyard) {
+		peer = list_entry(_p,struct rxrpc_peer,link);
+		if (peer->addr.s_addr==addr)
+			goto found_in_graveyard;
+	}
+	spin_unlock(&trans->peer_gylock);
+
+	/* we can now add the new candidate to the list
+	 * - tell the application layer that this peer has been added
+	 */
+	rxrpc_get_transport(trans);
+	peer = candidate;
+	candidate = NULL;
+
+	if (peer->ops && peer->ops->adding) {
+		ret = peer->ops->adding(peer);
+		if (ret<0) {
+			write_unlock(&trans->peer_lock);
+			__RXACCT(atomic_dec(&rxrpc_peer_count));
+			kfree(peer);
+			rxrpc_put_transport(trans);
+			_leave(" = %d",ret);
+			return ret;
+		}
+	}
+
+	atomic_inc(&trans->peer_count);
+
+ make_active:
+	list_add_tail(&peer->link,&trans->peer_active);
+
+ success_uwfree:
+	write_unlock(&trans->peer_lock);
+
+	if (candidate) {
+		__RXACCT(atomic_dec(&rxrpc_peer_count));
+		kfree(candidate);
+	}
+
+	if (list_empty(&peer->proc_link)) {
+		down_write(&rxrpc_peers_sem);
+		list_add_tail(&peer->proc_link,&rxrpc_peers);
+		up_write(&rxrpc_peers_sem);
+	}
+
+ success:
+	*_peer = peer;
+
+	_leave(" = 0 (%p{u=%d cc=%d})",
+	       peer,atomic_read(&peer->usage),atomic_read(&peer->conn_count));
+	return 0;
+
+	/* handle the peer being found in the active list straight off */
+ found_active:
+	rxrpc_get_peer(peer);
+	read_unlock(&trans->peer_lock);
+	goto success;
+
+	/* handle resurrecting a peer from the graveyard */
+ found_in_graveyard:
+	rxrpc_get_peer(peer);
+	rxrpc_get_transport(peer->trans);
+	rxrpc_krxtimod_del_timer(&peer->timeout);
+	list_del_init(&peer->link);
+	spin_unlock(&trans->peer_gylock);
+	goto make_active;
+
+	/* handle finding the peer on the second time through the active list */
+ found_active_second_chance:
+	rxrpc_get_peer(peer);
+	goto success_uwfree;
+
+} /* end rxrpc_peer_lookup() */
+
+/*****************************************************************************/
+/*
+ * finish with a peer record
+ * - it gets sent to the graveyard from where it can be resurrected or timed out
+ */
+void rxrpc_put_peer(struct rxrpc_peer *peer)
+{
+	struct rxrpc_transport *trans = peer->trans;
+
+	_enter("%p{cc=%d a=%08x}",peer,atomic_read(&peer->conn_count),ntohl(peer->addr.s_addr));
+
+	/* sanity check */
+	if (atomic_read(&peer->usage)<=0)
+		BUG();
+
+	write_lock(&trans->peer_lock);
+	spin_lock(&trans->peer_gylock);
+	if (likely(!atomic_dec_and_test(&peer->usage))) {
+		spin_unlock(&trans->peer_gylock);
+		write_unlock(&trans->peer_lock);
+		_leave("");
+		return;
+	}
+
+	/* move to graveyard queue */
+	list_del(&peer->link);
+	write_unlock(&trans->peer_lock);
+
+	list_add_tail(&peer->link,&trans->peer_graveyard);
+
+	if (!list_empty(&peer->conn_active)) BUG();
+
+	/* discard in 600 secs */
+	rxrpc_krxtimod_add_timer(&peer->timeout,100*HZ);
+
+	spin_unlock(&trans->peer_gylock);
+
+	rxrpc_put_transport(trans);
+
+	_leave(" [killed]");
+} /* end rxrpc_put_peer() */
+
+/*****************************************************************************/
+/*
+ * handle a peer timing out in the graveyard
+ * - called from krxtimod
+ */
+void rxrpc_peer_do_timeout(struct rxrpc_peer *peer)
+{
+	struct rxrpc_transport *trans = peer->trans;
+
+	_enter("%p{u=%d cc=%d a=%08x}",
+	       peer,atomic_read(&peer->usage),atomic_read(&peer->conn_count),
+	       ntohl(peer->addr.s_addr));
+
+	if (atomic_read(&peer->usage)<0)
+		BUG();
+
+	/* remove from graveyard if still dead */
+	spin_lock(&trans->peer_gylock);
+	if (atomic_read(&peer->usage)==0)
+		list_del_init(&peer->link);
+	else
+		peer = NULL;
+	spin_unlock(&trans->peer_gylock);
+
+	if (!peer) {
+		_leave("");
+		return; /* resurrected */
+	}
+
+	/* clear all connections on this peer */
+	rxrpc_conn_clearall(peer);
+
+	if (!list_empty(&peer->conn_active)) BUG();
+	if (!list_empty(&peer->conn_graveyard)) BUG();
+
+	/* inform the application layer */
+	if (peer->ops && peer->ops->discarding)
+		peer->ops->discarding(peer);
+
+	if (!list_empty(&peer->proc_link)) {
+		down_write(&rxrpc_peers_sem);
+		list_del(&peer->proc_link);
+		up_write(&rxrpc_peers_sem);
+	}
+
+	__RXACCT(atomic_dec(&rxrpc_peer_count));
+	kfree(peer);
+
+	/* if the graveyard is now empty, wake up anyone waiting for that */
+	if (atomic_dec_and_test(&trans->peer_count))
+		wake_up(&trans->peer_gy_waitq);
+
+	_leave(" [destroyed]");
+} /* end rxrpc_peer_do_timeout() */
+
+/*****************************************************************************/
+/*
+ * clear all peer records from a transport endpoint
+ */
+void rxrpc_peer_clearall(struct rxrpc_transport *trans)
+{
+	DECLARE_WAITQUEUE(myself,current);
+
+	struct rxrpc_peer *peer;
+	int err;
+
+	_enter("%p",trans);
+
+	/* there shouldn't be any active peers remaining */
+	if (!list_empty(&trans->peer_active))
+		BUG();
+
+	/* manually timeout all peers in the graveyard */
+	spin_lock(&trans->peer_gylock);
+	while (!list_empty(&trans->peer_graveyard)) {
+		peer = list_entry(trans->peer_graveyard.next,struct rxrpc_peer,link);
+		_debug("Clearing peer %p\n",peer);
+		err = rxrpc_krxtimod_del_timer(&peer->timeout);
+		spin_unlock(&trans->peer_gylock);
+
+		if (err==0)
+			rxrpc_peer_do_timeout(peer);
+
+		spin_lock(&trans->peer_gylock);
+	}
+	spin_unlock(&trans->peer_gylock);
+
+	/* wait for the the peer graveyard to be completely cleared */
+	set_current_state(TASK_UNINTERRUPTIBLE);
+	add_wait_queue(&trans->peer_gy_waitq,&myself);
+
+	while (atomic_read(&trans->peer_count)!=0) {
+		schedule();
+		set_current_state(TASK_UNINTERRUPTIBLE);
+	}
+
+	remove_wait_queue(&trans->peer_gy_waitq,&myself);
+	set_current_state(TASK_RUNNING);
+
+	_leave("");
+
+} /* end rxrpc_peer_clearall() */
+
+/*****************************************************************************/
+/*
+ * calculate and cache the Round-Trip-Time for a message and its response
+ */
+void rxrpc_peer_calculate_rtt(struct rxrpc_peer *peer,
+			      struct rxrpc_message *msg,
+			      struct rxrpc_message *resp)
+{
+	unsigned long long rtt;
+	int loop;
+
+	_enter("%p,%p,%p",peer,msg,resp);
+
+	/* calculate the latest RTT */
+	rtt = resp->stamp.tv_sec - msg->stamp.tv_sec;
+	rtt *= 1000000UL;
+	rtt += resp->stamp.tv_usec - msg->stamp.tv_usec;
+
+	/* add to cache */
+	peer->rtt_cache[peer->rtt_point] = rtt;
+	peer->rtt_point++;
+	peer->rtt_point %= RXRPC_RTT_CACHE_SIZE;
+
+	if (peer->rtt_usage<RXRPC_RTT_CACHE_SIZE) peer->rtt_usage++;
+
+	/* recalculate RTT */
+	for (loop=peer->rtt_usage-1; loop>=0; loop--)
+		rtt += peer->rtt_cache[loop];
+
+	peer->rtt = do_div(rtt,peer->rtt_usage);
+
+	_leave(" RTT=%lu.%lums",peer->rtt/1000,peer->rtt%1000);
+
+} /* end rxrpc_peer_calculate_rtt() */

net/rxrpc/proc.c

+/* proc.c: /proc interface for RxRPC
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <rxrpc/rxrpc.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/peer.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/call.h>
+#include <rxrpc/message.h>
+#include "internal.h"
+
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
+static inline struct proc_dir_entry *PDE(const struct inode *inode)
+{
+	return (struct proc_dir_entry *)inode->u.generic_ip;
+}
+#endif
+
+static struct proc_dir_entry *proc_rxrpc;
+
+static int rxrpc_proc_transports_open(struct inode *inode, struct file *file);
+static void *rxrpc_proc_transports_start(struct seq_file *p, loff_t *pos);
+static void *rxrpc_proc_transports_next(struct seq_file *p, void *v, loff_t *pos);
+static void rxrpc_proc_transports_stop(struct seq_file *p, void *v);
+static int rxrpc_proc_transports_show(struct seq_file *m, void *v);
+
+static struct seq_operations rxrpc_proc_transports_ops = {
+	.start	= rxrpc_proc_transports_start,
+	.next	= rxrpc_proc_transports_next,
+	.stop	= rxrpc_proc_transports_stop,
+	.show	= rxrpc_proc_transports_show,
+};
+
+static struct file_operations rxrpc_proc_transports_fops = {
+	.open		= rxrpc_proc_transports_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int rxrpc_proc_peers_open(struct inode *inode, struct file *file);
+static void *rxrpc_proc_peers_start(struct seq_file *p, loff_t *pos);
+static void *rxrpc_proc_peers_next(struct seq_file *p, void *v, loff_t *pos);
+static void rxrpc_proc_peers_stop(struct seq_file *p, void *v);
+static int rxrpc_proc_peers_show(struct seq_file *m, void *v);
+
+static struct seq_operations rxrpc_proc_peers_ops = {
+	.start	= rxrpc_proc_peers_start,
+	.next	= rxrpc_proc_peers_next,
+	.stop	= rxrpc_proc_peers_stop,
+	.show	= rxrpc_proc_peers_show,
+};
+
+static struct file_operations rxrpc_proc_peers_fops = {
+	.open		= rxrpc_proc_peers_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int rxrpc_proc_conns_open(struct inode *inode, struct file *file);
+static void *rxrpc_proc_conns_start(struct seq_file *p, loff_t *pos);
+static void *rxrpc_proc_conns_next(struct seq_file *p, void *v, loff_t *pos);
+static void rxrpc_proc_conns_stop(struct seq_file *p, void *v);
+static int rxrpc_proc_conns_show(struct seq_file *m, void *v);
+
+static struct seq_operations rxrpc_proc_conns_ops = {
+	.start	= rxrpc_proc_conns_start,
+	.next	= rxrpc_proc_conns_next,
+	.stop	= rxrpc_proc_conns_stop,
+	.show	= rxrpc_proc_conns_show,
+};
+
+static struct file_operations rxrpc_proc_conns_fops = {
+	.open		= rxrpc_proc_conns_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int rxrpc_proc_calls_open(struct inode *inode, struct file *file);
+static void *rxrpc_proc_calls_start(struct seq_file *p, loff_t *pos);
+static void *rxrpc_proc_calls_next(struct seq_file *p, void *v, loff_t *pos);
+static void rxrpc_proc_calls_stop(struct seq_file *p, void *v);
+static int rxrpc_proc_calls_show(struct seq_file *m, void *v);
+
+static struct seq_operations rxrpc_proc_calls_ops = {
+	.start	= rxrpc_proc_calls_start,
+	.next	= rxrpc_proc_calls_next,
+	.stop	= rxrpc_proc_calls_stop,
+	.show	= rxrpc_proc_calls_show,
+};
+
+static struct file_operations rxrpc_proc_calls_fops = {
+	.open		= rxrpc_proc_calls_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static const char *rxrpc_call_states7[] = {
+	"complet",
+	"error  ",
+	"rcv_op ",
+	"rcv_arg",
+	"got_arg",
+	"snd_rpl",
+	"fin_ack",
+	"snd_arg",
+	"rcv_rpl",
+	"got_rpl"
+};
+
+static const char *rxrpc_call_error_states7[] = {
+	"no_err ",
+	"loc_abt",
+	"rmt_abt",
+	"loc_err",
+	"rmt_err"
+};
+
+/*****************************************************************************/
+/*
+ * initialise the /proc/net/rxrpc/ directory
+ */
+int rxrpc_proc_init(void)
+{
+	struct proc_dir_entry *p;
+
+	proc_rxrpc = proc_mkdir("rxrpc",proc_net);
+	if (!proc_rxrpc)
+		goto error;
+	proc_rxrpc->owner = THIS_MODULE;
+
+	p = create_proc_entry("calls",0,proc_rxrpc);
+	if (!p)
+		goto error_proc;
+	p->proc_fops = &rxrpc_proc_calls_fops;
+	p->owner = THIS_MODULE;
+
+	p = create_proc_entry("connections",0,proc_rxrpc);
+	if (!p)
+		goto error_calls;
+	p->proc_fops = &rxrpc_proc_conns_fops;
+	p->owner = THIS_MODULE;
+
+	p = create_proc_entry("peers",0,proc_rxrpc);
+	if (!p)
+		goto error_calls;
+	p->proc_fops = &rxrpc_proc_peers_fops;
+	p->owner = THIS_MODULE;
+
+	p = create_proc_entry("transports",0,proc_rxrpc);
+	if (!p)
+		goto error_conns;
+	p->proc_fops = &rxrpc_proc_transports_fops;
+	p->owner = THIS_MODULE;
+
+	return 0;
+
+ error_conns:
+	remove_proc_entry("conns",proc_rxrpc);
+ error_calls:
+	remove_proc_entry("calls",proc_rxrpc);
+ error_proc:
+	remove_proc_entry("rxrpc",proc_net);
+ error:
+	return -ENOMEM;
+} /* end rxrpc_proc_init() */
+
+/*****************************************************************************/
+/*
+ * clean up the /proc/net/rxrpc/ directory
+ */
+void rxrpc_proc_cleanup(void)
+{
+	remove_proc_entry("transports",proc_rxrpc);
+	remove_proc_entry("peers",proc_rxrpc);
+	remove_proc_entry("connections",proc_rxrpc);
+	remove_proc_entry("calls",proc_rxrpc);
+
+	remove_proc_entry("rxrpc",proc_net);
+
+} /* end rxrpc_proc_cleanup() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/net/rxrpc/transports" which provides a summary of extant transports
+ */
+static int rxrpc_proc_transports_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *m;
+	int ret;
+
+	ret = seq_open(file,&rxrpc_proc_transports_ops);
+	if (ret<0)
+		return ret;
+
+	m = file->private_data;
+	m->private = PDE(inode)->data;
+
+	return 0;
+} /* end rxrpc_proc_transports_open() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the transports list and return the first item
+ */
+static void *rxrpc_proc_transports_start(struct seq_file *m, loff_t *_pos)
+{
+	struct list_head *_p;
+	loff_t pos = *_pos;
+
+	/* lock the list against modification */
+	down_read(&rxrpc_proc_transports_sem);
+
+	/* allow for the header line */
+	if (!pos)
+		return (void *)1;
+	pos--;
+
+	/* find the n'th element in the list */
+	list_for_each(_p,&rxrpc_proc_transports)
+		if (!pos--)
+			break;
+
+	return _p!=&rxrpc_proc_transports ? _p : NULL;
+} /* end rxrpc_proc_transports_start() */
+
+/*****************************************************************************/
+/*
+ * move to next call in transports list
+ */
+static void *rxrpc_proc_transports_next(struct seq_file *p, void *v, loff_t *pos)
+{
+	struct list_head *_p;
+
+	(*pos)++;
+
+	_p = v;
+	_p = v==(void*)1 ? rxrpc_proc_transports.next : _p->next;
+
+	return _p!=&rxrpc_proc_transports ? _p : NULL;
+} /* end rxrpc_proc_transports_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the transports list
+ */
+static void rxrpc_proc_transports_stop(struct seq_file *p, void *v)
+{
+	up_read(&rxrpc_proc_transports_sem);
+
+} /* end rxrpc_proc_transports_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of call lines
+ */
+static int rxrpc_proc_transports_show(struct seq_file *m, void *v)
+{
+	struct rxrpc_transport *trans = list_entry(v,struct rxrpc_transport,proc_link);
+
+	/* display header on line 1 */
+	if (v == (void *)1) {
+		seq_puts(m, "LOCAL USE\n");
+		return 0;
+	}
+
+	/* display one transport per line on subsequent lines */
+	seq_printf(m,"%5hu %3d\n",
+		   trans->port,
+		   atomic_read(&trans->usage)
+		   );
+
+	return 0;
+} /* end rxrpc_proc_transports_show() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/net/rxrpc/peers" which provides a summary of extant peers
+ */
+static int rxrpc_proc_peers_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *m;
+	int ret;
+
+	ret = seq_open(file,&rxrpc_proc_peers_ops);
+	if (ret<0)
+		return ret;
+
+	m = file->private_data;
+	m->private = PDE(inode)->data;
+
+	return 0;
+} /* end rxrpc_proc_peers_open() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the peers list and return the first item
+ */
+static void *rxrpc_proc_peers_start(struct seq_file *m, loff_t *_pos)
+{
+	struct list_head *_p;
+	loff_t pos = *_pos;
+
+	/* lock the list against modification */
+	down_read(&rxrpc_peers_sem);
+
+	/* allow for the header line */
+	if (!pos)
+		return (void *)1;
+	pos--;
+
+	/* find the n'th element in the list */
+	list_for_each(_p,&rxrpc_peers)
+		if (!pos--)
+			break;
+
+	return _p!=&rxrpc_peers ? _p : NULL;
+} /* end rxrpc_proc_peers_start() */
+
+/*****************************************************************************/
+/*
+ * move to next conn in peers list
+ */
+static void *rxrpc_proc_peers_next(struct seq_file *p, void *v, loff_t *pos)
+{
+	struct list_head *_p;
+
+	(*pos)++;
+
+	_p = v;
+	_p = v==(void*)1 ? rxrpc_peers.next : _p->next;
+
+	return _p!=&rxrpc_peers ? _p : NULL;
+} /* end rxrpc_proc_peers_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the peers list
+ */
+static void rxrpc_proc_peers_stop(struct seq_file *p, void *v)
+{
+	up_read(&rxrpc_peers_sem);
+
+} /* end rxrpc_proc_peers_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of conn lines
+ */
+static int rxrpc_proc_peers_show(struct seq_file *m, void *v)
+{
+	struct rxrpc_peer *peer = list_entry(v,struct rxrpc_peer,proc_link);
+	signed long timeout;
+
+	/* display header on line 1 */
+	if (v == (void *)1) {
+		seq_puts(m,"LOCAL REMOTE   USAGE CONNS  TIMEOUT   MTU RTT(uS)\n");
+		return 0;
+	}
+
+	/* display one peer per line on subsequent lines */
+	timeout = 0;
+	if (!list_empty(&peer->timeout.link))
+		timeout = (signed long)peer->timeout.timo_jif - (signed long)jiffies;
+
+	seq_printf(m,"%5hu %08x %5d %5d %8ld %5u %7lu\n",
+		   peer->trans->port,
+		   ntohl(peer->addr.s_addr),
+		   atomic_read(&peer->usage),
+		   atomic_read(&peer->conn_count),
+		   timeout,
+		   peer->if_mtu,
+		   peer->rtt
+		   );
+
+	return 0;
+} /* end rxrpc_proc_peers_show() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/net/rxrpc/connections" which provides a summary of extant connections
+ */
+static int rxrpc_proc_conns_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *m;
+	int ret;
+
+	ret = seq_open(file,&rxrpc_proc_conns_ops);
+	if (ret<0)
+		return ret;
+
+	m = file->private_data;
+	m->private = PDE(inode)->data;
+
+	return 0;
+} /* end rxrpc_proc_conns_open() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the conns list and return the first item
+ */
+static void *rxrpc_proc_conns_start(struct seq_file *m, loff_t *_pos)
+{
+	struct list_head *_p;
+	loff_t pos = *_pos;
+
+	/* lock the list against modification */
+	down_read(&rxrpc_conns_sem);
+
+	/* allow for the header line */
+	if (!pos)
+		return (void *)1;
+	pos--;
+
+	/* find the n'th element in the list */
+	list_for_each(_p,&rxrpc_conns)
+		if (!pos--)
+			break;
+
+	return _p!=&rxrpc_conns ? _p : NULL;
+} /* end rxrpc_proc_conns_start() */
+
+/*****************************************************************************/
+/*
+ * move to next conn in conns list
+ */
+static void *rxrpc_proc_conns_next(struct seq_file *p, void *v, loff_t *pos)
+{
+	struct list_head *_p;
+
+	(*pos)++;
+
+	_p = v;
+	_p = v==(void*)1 ? rxrpc_conns.next : _p->next;
+
+	return _p!=&rxrpc_conns ? _p : NULL;
+} /* end rxrpc_proc_conns_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the conns list
+ */
+static void rxrpc_proc_conns_stop(struct seq_file *p, void *v)
+{
+	up_read(&rxrpc_conns_sem);
+
+} /* end rxrpc_proc_conns_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of conn lines
+ */
+static int rxrpc_proc_conns_show(struct seq_file *m, void *v)
+{
+	struct rxrpc_connection *conn = list_entry(v,struct rxrpc_connection,proc_link);
+	signed long timeout;
+
+	/* display header on line 1 */
+	if (v == (void *)1) {
+		seq_puts(m,
+			 "LOCAL REMOTE   RPORT SRVC CONN     END SERIALNO CALLNO     MTU  TIMEOUT"
+			 "\n");
+		return 0;
+	}
+
+	/* display one conn per line on subsequent lines */
+	timeout = 0;
+	if (!list_empty(&conn->timeout.link))
+		timeout = (signed long)conn->timeout.timo_jif - (signed long)jiffies;
+
+	seq_printf(m,"%5hu %08x %5hu %04hx %08x %-3.3s %08x %08x %5u %8ld\n",
+		   conn->trans->port,
+		   ntohl(conn->addr.sin_addr.s_addr),
+		   ntohs(conn->addr.sin_port),
+		   ntohs(conn->service_id),
+		   ntohl(conn->conn_id),
+		   conn->out_clientflag ? "CLT" : "SRV",
+		   conn->serial_counter,
+		   conn->call_counter,
+		   conn->mtu_size,
+		   timeout
+		   );
+
+	return 0;
+} /* end rxrpc_proc_conns_show() */
+
+/*****************************************************************************/
+/*
+ * open "/proc/net/rxrpc/calls" which provides a summary of extant calls
+ */
+static int rxrpc_proc_calls_open(struct inode *inode, struct file *file)
+{
+	struct seq_file *m;
+	int ret;
+
+	ret = seq_open(file,&rxrpc_proc_calls_ops);
+	if (ret<0)
+		return ret;
+
+	m = file->private_data;
+	m->private = PDE(inode)->data;
+
+	return 0;
+} /* end rxrpc_proc_calls_open() */
+
+/*****************************************************************************/
+/*
+ * set up the iterator to start reading from the calls list and return the first item
+ */
+static void *rxrpc_proc_calls_start(struct seq_file *m, loff_t *_pos)
+{
+	struct list_head *_p;
+	loff_t pos = *_pos;
+
+	/* lock the list against modification */
+	down_read(&rxrpc_calls_sem);
+
+	/* allow for the header line */
+	if (!pos)
+		return (void *)1;
+	pos--;
+
+	/* find the n'th element in the list */
+	list_for_each(_p,&rxrpc_calls)
+		if (!pos--)
+			break;
+
+	return _p!=&rxrpc_calls ? _p : NULL;
+} /* end rxrpc_proc_calls_start() */
+
+/*****************************************************************************/
+/*
+ * move to next call in calls list
+ */
+static void *rxrpc_proc_calls_next(struct seq_file *p, void *v, loff_t *pos)
+{
+	struct list_head *_p;
+
+	(*pos)++;
+
+	_p = v;
+	_p = v==(void*)1 ? rxrpc_calls.next : _p->next;
+
+	return _p!=&rxrpc_calls ? _p : NULL;
+} /* end rxrpc_proc_calls_next() */
+
+/*****************************************************************************/
+/*
+ * clean up after reading from the calls list
+ */
+static void rxrpc_proc_calls_stop(struct seq_file *p, void *v)
+{
+	up_read(&rxrpc_calls_sem);
+
+} /* end rxrpc_proc_calls_stop() */
+
+/*****************************************************************************/
+/*
+ * display a header line followed by a load of call lines
+ */
+static int rxrpc_proc_calls_show(struct seq_file *m, void *v)
+{
+	struct rxrpc_call *call = list_entry(v,struct rxrpc_call,call_link);
+
+	/* display header on line 1 */
+	if (v == (void *)1) {
+		seq_puts(m,
+			 "LOCAL REMOT SRVC CONN     CALL     DIR USE "
+			 " L STATE   OPCODE ABORT    ERRNO\n"
+			 );
+		return 0;
+	}
+
+	/* display one call per line on subsequent lines */
+	seq_printf(m,
+		   "%5hu %5hu %04hx %08x %08x %s %3u%c"
+		   " %c %-7.7s %6d %08x %5d\n",
+		   call->conn->trans->port,
+		   ntohs(call->conn->addr.sin_port),
+		   ntohs(call->conn->service_id),
+		   ntohl(call->conn->conn_id),
+		   ntohl(call->call_id),
+		   call->conn->service ? "SVC" : "CLT",
+		   atomic_read(&call->usage),
+		   waitqueue_active(&call->waitq) ? 'w' : ' ',
+		   call->app_last_rcv ? 'Y' : '-',
+		   (call->app_call_state!=RXRPC_CSTATE_ERROR ?
+		    rxrpc_call_states7[call->app_call_state] :
+		    rxrpc_call_error_states7[call->app_err_state]),
+		   call->app_opcode,
+		   call->app_abort_code,
+		   call->app_errno
+		   );
+
+	return 0;
+} /* end rxrpc_proc_calls_show() */

net/rxrpc/rxrpc_syms.c

+/* rxrpc_syms.c: exported Rx RPC layer interface symbols
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <rxrpc/transport.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/call.h>
+#include <rxrpc/krxiod.h>
+
+/* call.c */
+EXPORT_SYMBOL(rxrpc_call_rcv_timeout);
+EXPORT_SYMBOL(rxrpc_call_acks_timeout);
+EXPORT_SYMBOL(rxrpc_call_dfr_ack_timeout);
+EXPORT_SYMBOL(rxrpc_call_max_resend);
+EXPORT_SYMBOL(rxrpc_call_states);
+EXPORT_SYMBOL(rxrpc_call_error_states);
+
+EXPORT_SYMBOL(rxrpc_create_call);
+EXPORT_SYMBOL(rxrpc_incoming_call);
+EXPORT_SYMBOL(rxrpc_put_call);
+EXPORT_SYMBOL(rxrpc_call_abort);
+EXPORT_SYMBOL(rxrpc_call_read_data);
+EXPORT_SYMBOL(rxrpc_call_write_data);
+EXPORT_SYMBOL(rxrpc_call_flush);
+
+/* connection.c */
+EXPORT_SYMBOL(rxrpc_create_connection);
+EXPORT_SYMBOL(rxrpc_put_connection);
+
+/* sysctl.c */
+EXPORT_SYMBOL(rxrpc_ktrace);
+EXPORT_SYMBOL(rxrpc_kdebug);
+EXPORT_SYMBOL(rxrpc_kproto);
+EXPORT_SYMBOL(rxrpc_knet);
+
+/* transport.c */
+EXPORT_SYMBOL(rxrpc_create_transport);
+EXPORT_SYMBOL(rxrpc_clear_transport);
+EXPORT_SYMBOL(rxrpc_put_transport);
+EXPORT_SYMBOL(rxrpc_add_service);
+EXPORT_SYMBOL(rxrpc_del_service);

net/rxrpc/sysctl.c

+/* sysctl.c: Rx RPC control
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/sysctl.h>
+#include <linux/config.h>
+#include <rxrpc/types.h>
+#include <rxrpc/rxrpc.h>
+#include <asm/errno.h>
+#include "internal.h"
+
+int rxrpc_ktrace;
+int rxrpc_kdebug;
+int rxrpc_kproto;
+int rxrpc_knet;
+
+#ifdef CONFIG_SYSCTL
+static struct ctl_table_header *rxrpc_sysctl = NULL;
+
+static ctl_table rxrpc_sysctl_table[] = {
+        { 1, "kdebug", &rxrpc_kdebug, sizeof(int), 0644, NULL, &proc_dointvec },
+        { 2, "ktrace", &rxrpc_ktrace, sizeof(int), 0644, NULL, &proc_dointvec },
+        { 3, "kproto", &rxrpc_kproto, sizeof(int), 0644, NULL, &proc_dointvec },
+        { 4, "knet",   &rxrpc_knet,   sizeof(int), 0644, NULL, &proc_dointvec },
+	{ 0 }
+};
+
+static ctl_table rxrpc_dir_sysctl_table[] = {
+	{ 1, "rxrpc", NULL, 0, 0555, rxrpc_sysctl_table },
+	{ 0 }
+};
+#endif /* CONFIG_SYSCTL */
+
+/*****************************************************************************/
+/*
+ * initialise the sysctl stuff for Rx RPC
+ */
+int rxrpc_sysctl_init(void)
+{
+#ifdef CONFIG_SYSCTL
+	rxrpc_sysctl = register_sysctl_table(rxrpc_dir_sysctl_table,0);
+	if (!rxrpc_sysctl)
+		return -ENOMEM;
+#endif /* CONFIG_SYSCTL */
+
+	return 0;
+} /* end rxrpc_sysctl_init() */
+
+/*****************************************************************************/
+/*
+ * clean up the sysctl stuff for Rx RPC
+ */
+void rxrpc_sysctl_cleanup(void)
+{
+#ifdef CONFIG_SYSCTL
+	if (rxrpc_sysctl) {
+		unregister_sysctl_table(rxrpc_sysctl);
+		rxrpc_sysctl = NULL;
+	}
+#endif /* CONFIG_SYSCTL */
+
+} /* end rxrpc_sysctl_cleanup() */

net/rxrpc/transport.c

+/* transport.c: Rx Transport routines
+ *
+ * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <rxrpc/transport.h>
+#include <rxrpc/peer.h>
+#include <rxrpc/connection.h>
+#include <rxrpc/call.h>
+#include <rxrpc/message.h>
+#include <rxrpc/krxiod.h>
+#include <rxrpc/krxsecd.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+#include <linux/ipv6.h>	/* this should _really_ be in errqueue.h.. */
+#endif
+#include <linux/errqueue.h>
+#include <asm/uaccess.h>
+#include <asm/checksum.h>
+#include "internal.h"
+
+struct errormsg {
+	struct cmsghdr			cmsg;		/* control message header */
+	struct sock_extended_err	ee;		/* extended error information */
+	struct sockaddr_in		icmp_src;	/* ICMP packet source address */
+};
+
+static spinlock_t rxrpc_transports_lock = SPIN_LOCK_UNLOCKED;
+static struct list_head rxrpc_transports = LIST_HEAD_INIT(rxrpc_transports);
+
+__RXACCT_DECL(atomic_t rxrpc_transport_count);
+LIST_HEAD(rxrpc_proc_transports);
+DECLARE_RWSEM(rxrpc_proc_transports_sem);
+
+static void rxrpc_data_ready(struct sock *sk, int count);
+static void rxrpc_error_report(struct sock *sk);
+static int rxrpc_trans_receive_new_call(struct rxrpc_transport *trans,
+					struct list_head *msgq);
+static void rxrpc_trans_receive_error_report(struct rxrpc_transport *trans);
+
+/*****************************************************************************/
+/*
+ * create a new transport endpoint using the specified UDP port
+ */
+int rxrpc_create_transport(unsigned short port, struct rxrpc_transport **_trans)
+{
+	struct rxrpc_transport *trans;
+	struct sockaddr_in sin;
+	mm_segment_t oldfs;
+	struct sock *sock;
+	int ret, opt;
+
+	_enter("%hu",port);
+
+	trans = kmalloc(sizeof(struct rxrpc_transport),GFP_KERNEL);
+	if (!trans)
+		return -ENOMEM;
+
+	memset(trans,0,sizeof(struct rxrpc_transport));
+	atomic_set(&trans->usage,1);
+	INIT_LIST_HEAD(&trans->services);
+	INIT_LIST_HEAD(&trans->link);
+	INIT_LIST_HEAD(&trans->krxiodq_link);
+	spin_lock_init(&trans->lock);
+	INIT_LIST_HEAD(&trans->peer_active);
+	INIT_LIST_HEAD(&trans->peer_graveyard);
+	spin_lock_init(&trans->peer_gylock);
+	init_waitqueue_head(&trans->peer_gy_waitq);
+	rwlock_init(&trans->peer_lock);
+	atomic_set(&trans->peer_count,0);
+	trans->port = port;
+
+	/* create a UDP socket to be my actual transport endpoint */
+	ret = sock_create(PF_INET,SOCK_DGRAM,IPPROTO_UDP,&trans->socket);
+	if (ret<0)
+		goto error;
+
+	/* use the specified port */
+	if (port) {
+		memset(&sin,0,sizeof(sin));
+		sin.sin_family = AF_INET;
+		sin.sin_port = htons(port);
+		ret = trans->socket->ops->bind(trans->socket,(struct sockaddr *)&sin,sizeof(sin));
+		if (ret<0)
+			goto error;
+	}
+
+	opt = 1;
+	oldfs = get_fs();
+	set_fs(KERNEL_DS);
+	ret = trans->socket->ops->setsockopt(trans->socket,SOL_IP,IP_RECVERR,
+					     (char*)&opt,sizeof(opt));
+	set_fs(oldfs);
+
+	spin_lock(&rxrpc_transports_lock);
+	list_add(&trans->link,&rxrpc_transports);
+	spin_unlock(&rxrpc_transports_lock);
+
+	/* set the socket up */
+	sock = trans->socket->sk;
+	sock->user_data = trans;
+	sock->data_ready = rxrpc_data_ready;
+	sock->error_report = rxrpc_error_report;
+
+	down_write(&rxrpc_proc_transports_sem);
+	list_add_tail(&trans->proc_link,&rxrpc_proc_transports);
+	up_write(&rxrpc_proc_transports_sem);
+
+	__RXACCT(atomic_inc(&rxrpc_transport_count));
+
+	*_trans = trans;
+	_leave(" = 0 (%p)",trans);
+	return 0;
+
+ error:
+	rxrpc_put_transport(trans);
+
+	_leave(" = %d",ret);
+
+	return ret;
+
+} /* end rxrpc_create_transport() */
+
+/*****************************************************************************/
+/*
+ * clear the connections on a transport endpoint
+ */
+void rxrpc_clear_transport(struct rxrpc_transport *trans)
+{
+	//struct rxrpc_connection *conn;
+
+} /* end rxrpc_clear_transport() */
+
+/*****************************************************************************/
+/*
+ * destroy a transport endpoint
+ */
+void rxrpc_put_transport(struct rxrpc_transport *trans)
+{
+	_enter("%p{u=%d p=%hu}",trans,atomic_read(&trans->usage),trans->port);
+
+	if (atomic_read(&trans->usage)<=0)
+		BUG();
+
+	/* to prevent a race, the decrement and the dequeue must be effectively atomic */
+	spin_lock(&rxrpc_transports_lock);
+	if (likely(!atomic_dec_and_test(&trans->usage))) {
+		spin_unlock(&rxrpc_transports_lock);
+		_leave("");
+		return;
+	}
+
+	list_del(&trans->link);
+	spin_unlock(&rxrpc_transports_lock);
+
+	/* finish cleaning up the transport */
+	if (trans->socket)
+		trans->socket->ops->shutdown(trans->socket,2);
+
+	rxrpc_krxsecd_clear_transport(trans);
+	rxrpc_krxiod_dequeue_transport(trans);
+
+	/* discard all peer information */
+	rxrpc_peer_clearall(trans);
+
+	down_write(&rxrpc_proc_transports_sem);
+	list_del(&trans->proc_link);
+	up_write(&rxrpc_proc_transports_sem);
+	__RXACCT(atomic_dec(&rxrpc_transport_count));
+
+	/* close the socket */
+	if (trans->socket) {
+		trans->socket->sk->user_data = NULL;
+		sock_release(trans->socket);
+		trans->socket = NULL;
+	}
+
+	kfree(trans);
+
+	_leave("");
+
+} /* end rxrpc_put_transport() */
+
+/*****************************************************************************/
+/*
+ * add a service to a transport to be listened upon
+ */
+int rxrpc_add_service(struct rxrpc_transport *trans, struct rxrpc_service *newsrv)
+{
+	struct rxrpc_service *srv;
+	struct list_head *_p;
+	int ret = -EEXIST;
+
+	_enter("%p{%hu},%p{%hu}",trans,trans->port,newsrv,newsrv->service_id);
+
+	/* verify that the service ID is not already present */
+	spin_lock(&trans->lock);
+
+	list_for_each(_p,&trans->services) {
+		srv = list_entry(_p,struct rxrpc_service,link);
+		if (srv->service_id==newsrv->service_id)
+			goto out;
+	}
+
+	/* okay - add the transport to the list */
+	list_add_tail(&newsrv->link,&trans->services);
+	rxrpc_get_transport(trans);
+	ret = 0;
+
+ out:
+	spin_unlock(&trans->lock);
+
+	_leave("= %d",ret);
+	return ret;
+
+} /* end rxrpc_add_service() */
+
+/*****************************************************************************/
+/*
+ * remove a service from a transport
+ */
+void rxrpc_del_service(struct rxrpc_transport *trans, struct rxrpc_service *srv)
+{
+	_enter("%p{%hu},%p{%hu}",trans,trans->port,srv,srv->service_id);
+
+	spin_lock(&trans->lock);
+	list_del(&srv->link);
+	spin_unlock(&trans->lock);
+
+	rxrpc_put_transport(trans);
+
+	_leave("");
+
+} /* end rxrpc_del_service() */
+
+/*****************************************************************************/
+/*
+ * INET callback when data has been received on the socket.
+ */
+static void rxrpc_data_ready(struct sock *sk, int count)
+{
+	struct rxrpc_transport *trans;
+
+	_enter("%p{t=%p},%d",sk,sk->user_data,count);
+
+	/* queue the transport for attention by krxiod */
+	trans = (struct rxrpc_transport *) sk->user_data;
+	if (trans)
+		rxrpc_krxiod_queue_transport(trans);
+
+	/* wake up anyone waiting on the socket */
+	if (sk->sleep && waitqueue_active(sk->sleep))
+		wake_up_interruptible(sk->sleep);
+
+	_leave("");
+
+} /* end rxrpc_data_ready() */
+
+/*****************************************************************************/
+/*
+ * INET callback when an ICMP error packet is received
+ * - sk->err is error (EHOSTUNREACH, EPROTO or EMSGSIZE)
+ */
+static void rxrpc_error_report(struct sock *sk)
+{
+	struct rxrpc_transport *trans;
+
+	_enter("%p{t=%p}",sk,sk->user_data);
+
+	/* queue the transport for attention by krxiod */
+	trans = (struct rxrpc_transport *) sk->user_data;
+	if (trans) {
+		trans->error_rcvd = 1;
+		rxrpc_krxiod_queue_transport(trans);
+	}
+
+	/* wake up anyone waiting on the socket */
+	if (sk->sleep && waitqueue_active(sk->sleep))
+		wake_up_interruptible(sk->sleep);
+
+	_leave("");
+
+} /* end rxrpc_error_report() */
+
+/*****************************************************************************/
+/*
+ * split a message up, allocating message records and filling them in from the contents of a
+ * socket buffer
+ */
+static int rxrpc_incoming_msg(struct rxrpc_transport *trans,
+			      struct sk_buff *pkt,
+			      struct list_head *msgq)
+{
+	struct rxrpc_message *msg;
+	int ret;
+
+	_enter("");
+
+	msg = kmalloc(sizeof(struct rxrpc_message),GFP_KERNEL);
+	if (!msg) {
+		_leave(" = -ENOMEM");
+		return -ENOMEM;
+	}
+
+	memset(msg,0,sizeof(*msg));
+	atomic_set(&msg->usage,1);
+	list_add_tail(&msg->link,msgq);
+
+	/* dig out the Rx routing parameters */
+	if (skb_copy_bits(pkt,sizeof(struct udphdr),&msg->hdr,sizeof(msg->hdr))<0) {
+		ret = -EBADMSG;
+		goto error;
+	}
+
+	msg->trans = trans;
+	msg->state = RXRPC_MSG_RECEIVED;
+	msg->stamp = pkt->stamp;
+	msg->seq = ntohl(msg->hdr.seq);
+
+	/* attach the packet */
+	skb_get(pkt);
+	msg->pkt = pkt;
+
+	msg->offset = sizeof(struct udphdr) + sizeof(struct rxrpc_header);
+	msg->dsize = msg->pkt->len - msg->offset;
+
+	_net("Rx Received packet from %s (%08x;%08x,%1x,%d,%s,%02x,%d,%d)",
+	     msg->hdr.flags & RXRPC_CLIENT_INITIATED ? "client" : "server",
+	     ntohl(msg->hdr.epoch),
+	     (ntohl(msg->hdr.cid) & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT,
+	     ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK,
+	     ntohl(msg->hdr.callNumber),
+	     rxrpc_pkts[msg->hdr.type],
+	     msg->hdr.flags,
+	     ntohs(msg->hdr.serviceId),
+	     msg->hdr.securityIndex);
+
+	__RXACCT(atomic_inc(&rxrpc_message_count));
+
+	/* split off jumbo packets */
+	while (msg->hdr.type==RXRPC_PACKET_TYPE_DATA && msg->hdr.flags & RXRPC_JUMBO_PACKET) {
+		struct rxrpc_jumbo_header jumbo;
+		struct rxrpc_message *jumbomsg = msg;
+
+		_debug("split jumbo packet");
+
+		/* quick sanity check */
+		ret = -EBADMSG;
+		if (msg->dsize < RXRPC_JUMBO_DATALEN+sizeof(struct rxrpc_jumbo_header))
+			goto error;
+		if (msg->hdr.flags & RXRPC_LAST_PACKET)
+			goto error;
+
+		/* dig out the secondary header */
+		if (skb_copy_bits(pkt,msg->offset+RXRPC_JUMBO_DATALEN,&jumbo,sizeof(jumbo))<0)
+			goto error;
+
+		/* allocate a new message record */
+		ret = -ENOMEM;
+		msg = kmalloc(sizeof(struct rxrpc_message),GFP_KERNEL);
+		if (!msg)
+			goto error;
+
+		memcpy(msg,jumbomsg,sizeof(*msg));
+		list_add_tail(&msg->link,msgq);
+
+		/* adjust the jumbo packet */
+		jumbomsg->dsize = RXRPC_JUMBO_DATALEN;
+
+		/* attach the packet here too */
+		skb_get(pkt);
+
+		/* adjust the parameters */
+		msg->seq++;
+		msg->hdr.seq = htonl(msg->seq);
+		msg->hdr.serial = htonl(ntohl(msg->hdr.serial) + 1);
+		msg->offset += RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header);
+		msg->dsize -= RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header);
+		msg->hdr.flags = jumbo.flags;
+		msg->hdr._rsvd = jumbo._rsvd;
+
+		_net("Rx Split jumbo packet from %s (%08x;%08x,%1x,%d,%s,%02x,%d,%d)",
+		     msg->hdr.flags & RXRPC_CLIENT_INITIATED ? "client" : "server",
+		     ntohl(msg->hdr.epoch),
+		     (ntohl(msg->hdr.cid) & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT,
+		     ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK,
+		     ntohl(msg->hdr.callNumber),
+		     rxrpc_pkts[msg->hdr.type],
+		     msg->hdr.flags,
+		     ntohs(msg->hdr.serviceId),
+		     msg->hdr.securityIndex);
+
+		__RXACCT(atomic_inc(&rxrpc_message_count));
+	}
+
+	_leave(" = 0 #%d",atomic_read(&rxrpc_message_count));
+	return 0;
+
+ error:
+	while (!list_empty(msgq)) {
+		msg = list_entry(msgq->next,struct rxrpc_message,link);
+		list_del_init(&msg->link);
+
+		rxrpc_put_message(msg);
+	}
+
+	_leave(" = %d",ret);
+	return ret;
+} /* end rxrpc_incoming_msg() */
+
+/*****************************************************************************/
+/*
+ * accept a new call
+ * - called from krxiod in process context
+ */
+void rxrpc_trans_receive_packet(struct rxrpc_transport *trans)
+{
+	struct rxrpc_message *msg;
+	struct rxrpc_peer *peer;
+	struct sk_buff *pkt;
+	int ret;
+	u32 addr;
+	u16 port;
+
+	LIST_HEAD(msgq);
+
+	_enter("%p{%d}",trans,trans->port);
+
+	for (;;) {
+		/* deal with outstanting errors first */
+		if (trans->error_rcvd)
+			rxrpc_trans_receive_error_report(trans);
+
+		/* attempt to receive a packet */
+		pkt = skb_recv_datagram(trans->socket->sk,0,1,&ret);
+		if (!pkt) {
+			if (ret==-EAGAIN) {
+				_leave(" EAGAIN");
+				return;
+			}
+
+			/* an icmp error may have occurred */
+			rxrpc_krxiod_queue_transport(trans);
+			_leave(" error %d\n",ret);
+			return;
+		}
+
+		/* we'll probably need to checksum it (didn't call sock_recvmsg) */
+		if (pkt->ip_summed != CHECKSUM_UNNECESSARY) {
+			if ((unsigned short)csum_fold(skb_checksum(pkt,0,pkt->len,pkt->csum))) {
+				kfree_skb(pkt);
+				rxrpc_krxiod_queue_transport(trans);
+				_leave(" CSUM failed");
+				return;
+			}
+		}
+
+		addr = pkt->nh.iph->saddr;
+		port = pkt->h.uh->source;
+
+		_net("Rx Received UDP packet from %08x:%04hu",ntohl(addr),ntohs(port));
+
+		/* unmarshall the Rx parameters and split jumbo packets */
+		ret = rxrpc_incoming_msg(trans,pkt,&msgq);
+		if (ret<0) {
+			kfree_skb(pkt);
+			rxrpc_krxiod_queue_transport(trans);
+			_leave(" bad packet");
+			return;
+		}
+
+		if (list_empty(&msgq)) BUG();
+
+		msg = list_entry(msgq.next,struct rxrpc_message,link);
+
+		/* locate the record for the peer from which it originated */
+		ret = rxrpc_peer_lookup(trans,addr,&peer);
+		if (ret<0) {
+			kdebug("Rx No connections from that peer");
+			rxrpc_trans_immediate_abort(trans,msg,-EINVAL);
+			goto finished_msg;
+		}
+
+		/* try and find a matching connection */
+		ret = rxrpc_connection_lookup(peer,msg,&msg->conn);
+		if (ret<0) {
+			kdebug("Rx Unknown Connection");
+			rxrpc_trans_immediate_abort(trans,msg,-EINVAL);
+			rxrpc_put_peer(peer);
+			goto finished_msg;
+		}
+		rxrpc_put_peer(peer);
+
+		/* deal with the first packet of a new call */
+		if (msg->hdr.flags & RXRPC_CLIENT_INITIATED &&
+		    msg->hdr.type==RXRPC_PACKET_TYPE_DATA &&
+		    ntohl(msg->hdr.seq)==1
+		    ) {
+			_debug("Rx New server call");
+			rxrpc_trans_receive_new_call(trans,&msgq);
+			goto finished_msg;
+		}
+
+		/* deal with subsequent packet(s) of call */
+		_debug("Rx Call packet");
+		while (!list_empty(&msgq)) {
+			msg = list_entry(msgq.next,struct rxrpc_message,link);
+			list_del_init(&msg->link);
+
+			ret = rxrpc_conn_receive_call_packet(msg->conn,NULL,msg);
+			if (ret<0) {
+				rxrpc_trans_immediate_abort(trans,msg,ret);
+				rxrpc_put_message(msg);
+				goto finished_msg;
+			}
+
+			rxrpc_put_message(msg);
+		}
+
+		goto finished_msg;
+
+		/* dispose of the packets */
+	finished_msg:
+		while (!list_empty(&msgq)) {
+			msg = list_entry(msgq.next,struct rxrpc_message,link);
+			list_del_init(&msg->link);
+
+			rxrpc_put_message(msg);
+		}
+		kfree_skb(pkt);
+	}
+
+	_leave("");
+
+} /* end rxrpc_trans_receive_packet() */
+
+/*****************************************************************************/
+/*
+ * accept a new call from a client trying to connect to one of my services
+ * - called in process context
+ */
+static int rxrpc_trans_receive_new_call(struct rxrpc_transport *trans,
+					struct list_head *msgq)
+{
+	struct rxrpc_message *msg;
+
+	_enter("");
+
+	/* only bother with the first packet */
+	msg = list_entry(msgq->next,struct rxrpc_message,link);
+	list_del_init(&msg->link);
+	rxrpc_krxsecd_queue_incoming_call(msg);
+	rxrpc_put_message(msg);
+
+	_leave(" = 0");
+
+	return 0;
+} /* end rxrpc_trans_receive_new_call() */
+
+/*****************************************************************************/
+/*
+ * perform an immediate abort without connection or call structures
+ */
+int rxrpc_trans_immediate_abort(struct rxrpc_transport *trans,
+				struct rxrpc_message *msg,
+				int error)
+{
+	struct rxrpc_header ahdr;
+	struct sockaddr_in sin;
+	struct msghdr msghdr;
+	struct iovec iov[2];
+	mm_segment_t oldfs;
+	int len, ret;
+	u32 _error;
+
+	_enter("%p,%p,%d",trans,msg,error);
+
+	/* don't abort an abort packet */
+	if (msg->hdr.type==RXRPC_PACKET_TYPE_ABORT) {
+		_leave(" = 0");
+		return 0;
+	}
+
+	_error = htonl(-error);
+
+	/* set up the message to be transmitted */
+	memcpy(&ahdr,&msg->hdr,sizeof(ahdr));
+	ahdr.epoch	= msg->hdr.epoch;
+	ahdr.serial	= htonl(1);
+	ahdr.seq	= 0;
+	ahdr.type	= RXRPC_PACKET_TYPE_ABORT;
+	ahdr.flags	= RXRPC_LAST_PACKET | (~msg->hdr.flags & RXRPC_CLIENT_INITIATED);
+
+	iov[0].iov_len	= sizeof(ahdr);
+	iov[0].iov_base	= &ahdr;
+	iov[1].iov_len	= sizeof(_error);
+	iov[1].iov_base	= &_error;
+
+	len = sizeof(ahdr) + sizeof(_error);
+
+	memset(&sin,0,sizeof(sin));
+	sin.sin_family		= AF_INET;
+	sin.sin_port		= msg->pkt->h.uh->source;
+	sin.sin_addr.s_addr	= msg->pkt->nh.iph->saddr;
+
+	msghdr.msg_name		= &sin;
+	msghdr.msg_namelen	= sizeof(sin);
+	msghdr.msg_iov		= iov;
+	msghdr.msg_iovlen	= 2;
+	msghdr.msg_control	= NULL;
+	msghdr.msg_controllen	= 0;
+	msghdr.msg_flags	= MSG_DONTWAIT;
+
+	_net("Sending message type %d of %d bytes to %08x:%d",
+	     ahdr.type,
+	     len,
+	     htonl(sin.sin_addr.s_addr),
+	     htons(sin.sin_port));
+
+	/* send the message */
+	oldfs = get_fs();
+	set_fs(KERNEL_DS);
+	ret = sock_sendmsg(trans->socket,&msghdr,len);
+	set_fs(oldfs);
+
+	_leave(" = %d",ret);
+	return ret;
+} /* end rxrpc_trans_immediate_abort() */
+
+/*****************************************************************************/
+/*
+ * receive an ICMP error report and percolate it to all connections heading to the affected
+ * host or port
+ */
+static void rxrpc_trans_receive_error_report(struct rxrpc_transport *trans)
+{
+	struct rxrpc_connection *conn;
+	struct sockaddr_in sin;
+	struct rxrpc_peer *peer;
+	struct list_head connq, *_p;
+	struct errormsg emsg;
+	struct msghdr msg;
+	mm_segment_t oldfs;
+	int local, err;
+	u16 port;
+
+	_enter("%p",trans);
+
+	for (;;) {
+		trans->error_rcvd = 0;
+
+		/* try and receive an error message */
+		msg.msg_name	= &sin;
+		msg.msg_namelen	= sizeof(sin);
+		msg.msg_iov	= NULL;
+		msg.msg_iovlen	= 0;
+		msg.msg_control	= &emsg;
+		msg.msg_controllen = sizeof(emsg);
+		msg.msg_flags	= 0;
+
+		oldfs = get_fs();
+		set_fs(KERNEL_DS);
+		err = sock_recvmsg(trans->socket,&msg,0,MSG_ERRQUEUE|MSG_DONTWAIT|MSG_TRUNC);
+		set_fs(oldfs);
+
+		if (err==-EAGAIN) {
+			_leave("");
+			return;
+		}
+
+		if (err<0) {
+			printk("%s: unable to recv an error report: %d\n",__FUNCTION__,err);
+			_leave("");
+			return;
+		}
+
+		msg.msg_controllen = (char*)msg.msg_control - (char*)&emsg;
+
+		if (msg.msg_controllen<sizeof(emsg.cmsg) || msg.msg_namelen<sizeof(sin)) {
+			printk("%s: short control message (nlen=%u clen=%u fl=%x)\n",
+			       __FUNCTION__,msg.msg_namelen,msg.msg_controllen,msg.msg_flags);
+			continue;
+		}
+
+		_net("Rx Received control message { len=%u level=%u type=%u }",
+		     emsg.cmsg.cmsg_len,emsg.cmsg.cmsg_level,emsg.cmsg.cmsg_type);
+
+		if (sin.sin_family!=AF_INET) {
+			printk("Rx Ignoring error report with non-INET address (fam=%u)",
+			       sin.sin_family);
+			continue;
+		}
+
+		_net("Rx Received message pertaining to host addr=%x port=%hu",
+		     ntohl(sin.sin_addr.s_addr),ntohs(sin.sin_port));
+
+		if (emsg.cmsg.cmsg_level!=SOL_IP || emsg.cmsg.cmsg_type!=IP_RECVERR) {
+			printk("Rx Ignoring unknown error report { level=%u type=%u }",
+			       emsg.cmsg.cmsg_level,emsg.cmsg.cmsg_type);
+			continue;
+		}
+
+		if (msg.msg_controllen<sizeof(emsg.cmsg)+sizeof(emsg.ee)) {
+			printk("%s: short error message (%u)\n",__FUNCTION__,msg.msg_controllen);
+			_leave("");
+			return;
+		}
+
+		port = sin.sin_port;
+
+		switch (emsg.ee.ee_origin) {
+		case SO_EE_ORIGIN_ICMP:
+			local = 0;
+			switch (emsg.ee.ee_type) {
+			case ICMP_DEST_UNREACH:
+				switch (emsg.ee.ee_code) {
+				case ICMP_NET_UNREACH:
+					_net("Rx Received ICMP Network Unreachable");
+					port = 0;
+					err = -ENETUNREACH;
+					break;
+				case ICMP_HOST_UNREACH:
+					_net("Rx Received ICMP Host Unreachable");
+					port = 0;
+					err = -EHOSTUNREACH;
+					break;
+				case ICMP_PORT_UNREACH:
+					_net("Rx Received ICMP Port Unreachable");
+					err = -ECONNREFUSED;
+					break;
+				case ICMP_NET_UNKNOWN:
+					_net("Rx Received ICMP Unknown Network");
+					port = 0;
+					err = -ENETUNREACH;
+					break;
+				case ICMP_HOST_UNKNOWN:
+					_net("Rx Received ICMP Unknown Host");
+					port = 0;
+					err = -EHOSTUNREACH;
+					break;
+				default:
+					_net("Rx Received ICMP DestUnreach { code=%u }",
+					     emsg.ee.ee_code);
+					err = emsg.ee.ee_errno;
+					break;
+				}
+				break;
+
+			case ICMP_TIME_EXCEEDED:
+				_net("Rx Received ICMP TTL Exceeded");
+				err = emsg.ee.ee_errno;
+				break;
+
+			default:
+				_proto("Rx Received ICMP error { type=%u code=%u }",
+				       emsg.ee.ee_type,emsg.ee.ee_code);
+				err = emsg.ee.ee_errno;
+				break;
+			}
+			break;
+
+		case SO_EE_ORIGIN_LOCAL:
+			_proto("Rx Received local error { error=%d }",emsg.ee.ee_errno);
+			local = 1;
+			err = emsg.ee.ee_errno;
+			break;
+
+		case SO_EE_ORIGIN_NONE:
+		case SO_EE_ORIGIN_ICMP6:
+		default:
+			_proto("Rx Received error report { orig=%u }",emsg.ee.ee_origin);
+			local = 0;
+			err = emsg.ee.ee_errno;
+			break;
+		}
+
+		/* find all the connections between this transport and the affected destination */
+		INIT_LIST_HEAD(&connq);
+
+		if (rxrpc_peer_lookup(trans,sin.sin_addr.s_addr,&peer)==0) {
+			read_lock(&peer->conn_lock);
+			list_for_each(_p,&peer->conn_active) {
+				conn = list_entry(_p,struct rxrpc_connection,link);
+				if (port && conn->addr.sin_port!=port)
+					continue;
+				if (!list_empty(&conn->err_link))
+					continue;
+
+				rxrpc_get_connection(conn);
+				list_add_tail(&conn->err_link,&connq);
+			}
+			read_unlock(&peer->conn_lock);
+
+			/* service all those connections */
+			while (!list_empty(&connq)) {
+				conn = list_entry(connq.next,struct rxrpc_connection,err_link);
+				list_del(&conn->err_link);
+
+				rxrpc_conn_handle_error(conn,local,err);
+
+				rxrpc_put_connection(conn);
+			}
+
+			rxrpc_put_peer(peer);
+		}
+	}
+
+	_leave("");
+	return;
+} /* end rxrpc_trans_receive_error_report() */