Phonet: Pipe End Point for Phonet Pipes protocol

This protocol provides some connection handling and negotiated
congestion control. Nokia cellular modems use it for bulk transfers.
It provides packet boundaries (hence SOCK_SEQPACKET). Congestion
control is per packet rather per byte, so we do not re-use the
generic socket memory accounting.
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/phonet.h

@@ -27,7 +27,9 @@
 #define PN_PROTO_TRANSPORT	0
 /* Phonet datagram socket */
 #define PN_PROTO_PHONET		1
-#define PHONET_NPROTO		2
+/* Phonet pipe */
+#define PN_PROTO_PIPE		2
+#define PHONET_NPROTO		3
 
 #define PNADDR_ANY		0
 #define PNPORT_RESOURCE_ROUTING	0

include/net/phonet/pep.h

@@ -26,11 +26,21 @@
 struct pep_sock {
 	struct pn_sock		pn_sk;
 
+	/* XXX: union-ify listening vs connected stuff ? */
 	/* Listening socket stuff: */
 	struct hlist_head	ackq;
+	struct hlist_head	hlist;
 
 	/* Connected socket stuff: */
+	struct sock		*listener;
+	u16			peer_type;	/* peer type/subtype */
+	u8			pipe_handle;
+
+	u8			rx_credits;
 	u8			tx_credits;
+	u8			rx_fc;	/* RX flow control */
+	u8			tx_fc;	/* TX flow control */
+	u8			init_enable;	/* auto-enable at creation */
 };
 
 static inline struct pep_sock *pep_sk(struct sock *sk)
@@ -40,4 +50,108 @@ static inline struct pep_sock *pep_sk(struct sock *sk)
 
 extern const struct proto_ops phonet_stream_ops;
 
+/* Pipe protocol definitions */
+struct pnpipehdr {
+	u8			utid; /* transaction ID */
+	u8			message_id;
+	u8			pipe_handle;
+	union {
+		u8		state_after_connect;	/* connect request */
+		u8		state_after_reset;	/* reset request */
+		u8		error_code;		/* any response */
+		u8		pep_type;		/* status indication */
+		u8		data[1];
+	};
+};
+#define other_pep_type		data[1]
+
+static inline struct pnpipehdr *pnp_hdr(struct sk_buff *skb)
+{
+	return (struct pnpipehdr *)skb_transport_header(skb);
+}
+
+#define MAX_PNPIPE_HEADER (MAX_PHONET_HEADER + 4)
+
+enum {
+	PNS_PIPE_DATA = 0x20,
+
+	PNS_PEP_CONNECT_REQ = 0x40,
+	PNS_PEP_CONNECT_RESP,
+	PNS_PEP_DISCONNECT_REQ,
+	PNS_PEP_DISCONNECT_RESP,
+	PNS_PEP_RESET_REQ,
+	PNS_PEP_RESET_RESP,
+	PNS_PEP_ENABLE_REQ,
+	PNS_PEP_ENABLE_RESP,
+	PNS_PEP_CTRL_REQ,
+	PNS_PEP_CTRL_RESP,
+	PNS_PEP_DISABLE_REQ = 0x4C,
+	PNS_PEP_DISABLE_RESP,
+
+	PNS_PEP_STATUS_IND = 0x60,
+	PNS_PIPE_CREATED_IND,
+	PNS_PIPE_RESET_IND = 0x63,
+	PNS_PIPE_ENABLED_IND,
+	PNS_PIPE_REDIRECTED_IND,
+	PNS_PIPE_DISABLED_IND = 0x66,
+};
+
+#define PN_PIPE_INVALID_HANDLE	0xff
+#define PN_PEP_TYPE_COMMON	0x00
+
+/* Phonet pipe status indication */
+enum {
+	PN_PEP_IND_FLOW_CONTROL,
+	PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
+};
+
+/* Phonet pipe error codes */
+enum {
+	PN_PIPE_NO_ERROR,
+	PN_PIPE_ERR_INVALID_PARAM,
+	PN_PIPE_ERR_INVALID_HANDLE,
+	PN_PIPE_ERR_INVALID_CTRL_ID,
+	PN_PIPE_ERR_NOT_ALLOWED,
+	PN_PIPE_ERR_PEP_IN_USE,
+	PN_PIPE_ERR_OVERLOAD,
+	PN_PIPE_ERR_DEV_DISCONNECTED,
+	PN_PIPE_ERR_TIMEOUT,
+	PN_PIPE_ERR_ALL_PIPES_IN_USE,
+	PN_PIPE_ERR_GENERAL,
+	PN_PIPE_ERR_NOT_SUPPORTED,
+};
+
+/* Phonet pipe states */
+enum {
+	PN_PIPE_DISABLE,
+	PN_PIPE_ENABLE,
+};
+
+/* Phonet pipe sub-block types */
+enum {
+	PN_PIPE_SB_CREATE_REQ_PEP_SUB_TYPE,
+	PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE,
+	PN_PIPE_SB_REDIRECT_REQ_PEP_SUB_TYPE,
+	PN_PIPE_SB_NEGOTIATED_FC,
+	PN_PIPE_SB_REQUIRED_FC_TX,
+	PN_PIPE_SB_PREFERRED_FC_RX,
+};
+
+/* Phonet pipe flow control models */
+enum {
+	PN_NO_FLOW_CONTROL,
+	PN_LEGACY_FLOW_CONTROL,
+	PN_ONE_CREDIT_FLOW_CONTROL,
+	PN_MULTI_CREDIT_FLOW_CONTROL,
+};
+
+#define pn_flow_safe(fc) ((fc) >> 1)
+
+/* Phonet pipe flow control states */
+enum {
+	PEP_IND_EMPTY,
+	PEP_IND_BUSY,
+	PEP_IND_READY,
+};
+
 #endif

net/phonet/Makefile

-obj-$(CONFIG_PHONET) += phonet.o
+obj-$(CONFIG_PHONET) += phonet.o pn_pep.o
 
 phonet-objs := \
 	pn_dev.o \
@@ -7,3 +7,5 @@ phonet-objs := \
 	datagram.o \
 	sysctl.o \
 	af_phonet.o
+
+pn_pep-objs := pep.o

net/phonet/af_phonet.c

@@ -58,6 +58,9 @@ static int pn_socket_create(struct net *net, struct socket *sock, int protocol)
 		case SOCK_DGRAM:
 			protocol = PN_PROTO_PHONET;
 			break;
+		case SOCK_SEQPACKET:
+			protocol = PN_PROTO_PIPE;
+			break;
 		default:
 			return -EPROTONOSUPPORT;
 		}