[ATM]: Forward port br2864 to 2.5.x

include/linux/atmbr2684.h

+#ifndef _LINUX_ATMBR2684_H
+#define _LINUX_ATMBR2684_H
+
+#include <linux/atm.h>
+#include <linux/if.h>		/* For IFNAMSIZ */
+
+/*
+ * Type of media we're bridging (ethernet, token ring, etc)  Currently only
+ * ethernet is supported
+ */
+#define BR2684_MEDIA_ETHERNET	(0)	/* 802.3 */
+#define BR2684_MEDIA_802_4	(1)	/* 802.4 */
+#define BR2684_MEDIA_TR		(2)	/* 802.5 - token ring */
+#define BR2684_MEDIA_FDDI	(3)
+#define BR2684_MEDIA_802_6	(4)	/* 802.6 */
+
+/*
+ * Is there FCS inbound on this VC?  This currently isn't supported.
+ */
+#define BR2684_FCSIN_NO		(0)
+#define BR2684_FCSIN_IGNORE	(1)
+#define BR2684_FCSIN_VERIFY	(2)
+
+/*
+ * Is there FCS outbound on this VC?  This currently isn't supported.
+ */
+#define BR2684_FCSOUT_NO	(0)
+#define BR2684_FCSOUT_SENDZERO	(1)
+#define BR2684_FCSOUT_GENERATE	(2)
+
+/*
+ * Does this VC include LLC encapsulation?
+ */
+#define BR2684_ENCAPS_VC	(0)	/* VC-mux */
+#define BR2684_ENCAPS_LLC	(1)
+#define BR2684_ENCAPS_AUTODETECT (2)	/* Unsuported */
+
+/*
+ * This is for the ATM_NEWBACKENDIF call - these are like socket families:
+ * the first element of the structure is the backend number and the rest
+ * is per-backend specific
+ */
+struct atm_newif_br2684 {
+	atm_backend_t	backend_num;	/* ATM_BACKEND_BR2684 */
+	int		media;		/* BR2684_MEDIA_* */
+	char		ifname[IFNAMSIZ];
+	int		mtu;
+};
+
+/*
+ * This structure is used to specify a br2684 interface - either by a
+ * positive integer (returned by ATM_NEWBACKENDIF) or the interfaces name
+ */
+#define BR2684_FIND_BYNOTHING	(0)
+#define BR2684_FIND_BYNUM	(1)
+#define BR2684_FIND_BYIFNAME	(2)
+struct br2684_if_spec {
+	int method;			/* BR2684_FIND_* */
+	union {
+		char		ifname[IFNAMSIZ];
+		int		devnum;
+	} spec;
+};
+
+/*
+ * This is for the ATM_SETBACKEND call - these are like socket families:
+ * the first element of the structure is the backend number and the rest
+ * is per-backend specific
+ */
+struct atm_backend_br2684 {
+	atm_backend_t	backend_num;	/* ATM_BACKEND_BR2684 */
+	struct br2684_if_spec ifspec;
+	int	fcs_in;		/* BR2684_FCSIN_* */
+	int	fcs_out;	/* BR2684_FCSOUT_* */
+	int	fcs_auto;	/* 1: fcs_{in,out} disabled if no FCS rx'ed */
+	int	encaps;		/* BR2684_ENCAPS_* */
+	int	has_vpiid;	/* 1: use vpn_id - Unsupported */
+	__u8	vpn_id[7];
+	int	send_padding;	/* unsupported */
+	int	min_size;	/* we will pad smaller packets than this */
+};
+
+/*
+ * The BR2684_SETFILT ioctl is an experimental mechanism for folks
+ * terminating a large number of IP-only vcc's.  When netfilter allows
+ * efficient per-if in/out filters, this support will be removed
+ */
+struct br2684_filter {
+	__u32	prefix;		/* network byte order */
+	__u32	netmask;	/* 0 = disable filter */
+};
+
+struct br2684_filter_set {
+	struct br2684_if_spec ifspec;
+	struct br2684_filter filter;
+};
+
+#define BR2684_SETFILT	_IOW( 'a', ATMIOC_BACKEND + 0, \
+				struct br2684_filter_set)
+
+#endif /* _LINUX_ATMBR2684_H */

include/linux/atmdev.h

@@ -96,6 +96,8 @@ struct atm_dev_stats {
 					/* enable or disable single-copy */
 #define ATM_SETBACKEND	_IOW('a',ATMIOC_SPECIAL+2,atm_backend_t)
 					/* set backend handler */
+#define ATM_NEWBACKENDIF _IOW('a',ATMIOC_SPECIAL+3,atm_backend_t)
+					/* use backend to make new if */
 
 /*
  * These are backend handkers that can be set via the ATM_SETBACKEND call
@@ -104,7 +106,7 @@ struct atm_dev_stats {
  */
 #define ATM_BACKEND_RAW		0	
 #define ATM_BACKEND_PPP		1	/* PPPoATM - RFC2364 */
-#define ATM_BACKEND_BR_2684	2	/* Bridged RFC1483/2684 */
+#define ATM_BACKEND_BR2684	2	/* Bridged RFC1483/2684 */
 
 /* for ATM_GETTYPE */
 #define ATM_ITFTYP_LEN	8	/* maximum length of interface type name */

net/Kconfig

@@ -266,6 +266,23 @@ config ATM_MPOA
 	  subnetwork boundaries. These shortcut connections bypass routers
 	  enhancing overall network performance.
 
+config ATM_BR2684
+	tristate "RFC1483/2684 Bridged protocols"
+	depends on ATM && INET
+	help
+	  ATM PVCs can carry ethernet PDUs according to rfc2684 (formerly 1483)
+	  This device will act like an ethernet from the kernels point of view,
+	  with the traffic being carried by ATM PVCs (currently 1 PVC/device).
+	  This is sometimes used over DSL lines.  If in doubt, say N.
+
+config ATM_BR2684_IPFILTER
+	bool "Per-VC IP filter kludge"
+	depends on ATM_BR2684
+	help
+	  This is an experimental mechanism for users who need to terminating a
+	  large number of IP-only vcc's.  Do not enable this unless you are sure
+	  you know what you are doing.
+
 config VLAN_8021Q
 	tristate "802.1Q VLAN Support"
 

net/atm/Makefile

@@ -7,6 +7,7 @@ mpoa-objs	:= mpc.o mpoa_caches.o mpoa_proc.o
 obj-$(CONFIG_ATM) := addr.o pvc.o signaling.o svc.o common.o atm_misc.o raw.o resources.o
 
 obj-$(CONFIG_ATM_CLIP) += clip.o ipcommon.o
+obj-$(CONFIG_ATM_BR2684) += br2684.o ipcommon.o
 obj-$(CONFIG_NET_SCH_ATM) += ipcommon.o
 obj-$(CONFIG_PROC_FS) += proc.o
 

net/atm/br2684.c

+/*
+Experimental ethernet netdevice using ATM AAL5 as underlying carrier
+(RFC1483 obsoleted by RFC2684) for Linux 2.4
+Author: Marcell GAL, 2000, XDSL Ltd, Hungary
+*/
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/ip.h>
+#include <asm/uaccess.h>
+#include <net/arp.h>
+
+#include <linux/atmbr2684.h>
+
+#include "ipcommon.h"
+
+/*
+ * Define this to use a version of the code which interacts with the higher
+ * layers in a more intellegent way, by always reserving enough space for
+ * our header at the begining of the packet.  However, there may still be
+ * some problems with programs like tcpdump.  In 2.5 we'll sort out what
+ * we need to do to get this perfect.  For now we just will copy the packet
+ * if we need space for the header
+ */
+/* #define FASTER_VERSION */
+
+#ifdef DEBUG
+#define DPRINTK(format, args...) printk(KERN_DEBUG "br2684: " format, ##args)
+#else
+#define DPRINTK(format, args...)
+#endif
+
+#ifdef SKB_DEBUG
+static void skb_debug(const struct sk_buff *skb)
+{
+#define NUM2PRINT 50
+	char buf[NUM2PRINT * 3 + 1];	/* 3 chars per byte */
+	int i = 0;
+	for (i = 0; i < skb->len && i < NUM2PRINT; i++) {
+		sprintf(buf + i * 3, "%2.2x ", 0xff & skb->data[i]);
+	}
+	printk(KERN_DEBUG "br2684: skb: %s\n", buf);
+}
+#else
+#define skb_debug(skb)	do {} while (0)
+#endif
+
+static unsigned char llc_oui_pid_pad[] =
+    { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
+#define PADLEN	(2)
+
+enum br2684_encaps {
+	e_vc  = BR2684_ENCAPS_VC,
+	e_llc = BR2684_ENCAPS_LLC,
+};
+
+struct br2684_vcc {
+	struct atm_vcc  *atmvcc;
+	struct br2684_dev *brdev;
+	/* keep old push,pop functions for chaining */
+	void (*old_push)(struct atm_vcc *vcc,struct sk_buff *skb);
+	/* void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); */
+	enum br2684_encaps encaps;
+	struct list_head brvccs;
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	struct br2684_filter filter;
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+#ifndef FASTER_VERSION
+	unsigned copies_needed, copies_failed;
+#endif /* FASTER_VERSION */
+};
+
+struct br2684_dev {
+	struct net_device net_dev;
+	struct list_head br2684_devs;
+	int number;
+	struct list_head brvccs; /* one device <=> one vcc (before xmas) */
+	struct net_device_stats stats;
+	int mac_was_set;
+};
+
+/*
+ * This lock should be held for writing any time the list of devices or
+ * their attached vcc's could be altered.  It should be held for reading
+ * any time these are being queried.  Note that we sometimes need to
+ * do read-locking under interrupt context, so write locking must block
+ * the current CPU's interrupts
+ */
+static rwlock_t devs_lock = RW_LOCK_UNLOCKED;
+
+static LIST_HEAD(br2684_devs);
+
+static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
+{
+	return (struct br2684_dev *) ((char *) (net_dev) -
+	    (unsigned long) (&((struct br2684_dev *) 0)->net_dev));
+}
+
+static inline struct br2684_dev *list_entry_brdev(const struct list_head *le)
+{
+	return list_entry(le, struct br2684_dev, br2684_devs);
+}
+
+static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
+{
+	return (struct br2684_vcc *) (atmvcc->user_back);
+}
+
+static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
+{
+	return list_entry(le, struct br2684_vcc, brvccs);
+}
+
+/* Caller should hold read_lock(&devs_lock) */
+static struct br2684_dev *br2684_find_dev(const struct br2684_if_spec *s)
+{
+	struct list_head *lh;
+	struct br2684_dev *brdev;
+	switch (s->method) {
+	case BR2684_FIND_BYNUM:
+		list_for_each(lh, &br2684_devs) {
+			brdev = list_entry_brdev(lh);
+			if (brdev->number == s->spec.devnum)
+				return brdev;
+		}
+		break;
+	case BR2684_FIND_BYIFNAME:
+		list_for_each(lh, &br2684_devs) {
+			brdev = list_entry_brdev(lh);
+			if (!strncmp(brdev->net_dev.name, s->spec.ifname,
+			    sizeof brdev->net_dev.name))
+				return brdev;
+		}
+		break;
+	}
+	return NULL;
+}
+
+/*
+ * Send a packet out a particular vcc.  Not to useful right now, but paves
+ * the way for multiple vcc's per itf.  Returns true if we can send,
+ * otherwise false
+ */
+static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
+	struct br2684_vcc *brvcc)
+{
+	struct atm_vcc *atmvcc;
+#ifdef FASTER_VERSION
+	if (brvcc->encaps == e_llc)
+		memcpy(skb_push(skb, 8), llc_oui_pid_pad, 8);
+	/* last 2 bytes of llc_oui_pid_pad are managed by header routines;
+	   yes, you got it: 8 + 2 = sizeof(llc_oui_pid_pad)
+	 */
+#else
+	int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
+	if (skb_headroom(skb) < minheadroom) {
+		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
+		brvcc->copies_needed++;
+		dev_kfree_skb(skb);
+		if (skb2 == NULL) {
+			brvcc->copies_failed++;
+			return 0;
+		}
+		skb = skb2;
+	}
+	skb_push(skb, minheadroom);
+	if (brvcc->encaps == e_llc)
+		memcpy(skb->data, llc_oui_pid_pad, 10);
+	else
+		memset(skb->data, 0, 2);
+#endif /* FASTER_VERSION */
+	skb_debug(skb);
+
+	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
+	DPRINTK("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
+	if (!atm_may_send(atmvcc, skb->truesize)) {
+		/* we free this here for now, because we cannot know in a higher 
+			layer whether the skb point it supplied wasn't freed yet.
+			now, it always is.
+		*/
+		dev_kfree_skb(skb);
+		return 0;
+		}
+	atomic_add(skb->truesize, &atmvcc->sk->wmem_alloc);
+	ATM_SKB(skb)->atm_options = atmvcc->atm_options;
+	brdev->stats.tx_packets++;
+	brdev->stats.tx_bytes += skb->len;
+	atmvcc->send(atmvcc, skb);
+	return 1;
+}
+
+static inline struct br2684_vcc *pick_outgoing_vcc(struct sk_buff *skb,
+	struct br2684_dev *brdev)
+{
+	return list_empty(&brdev->brvccs) ? NULL :
+	    list_entry_brvcc(brdev->brvccs.next); /* 1 vcc/dev right now */
+}
+
+static int br2684_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct br2684_dev *brdev = BRPRIV(dev);
+	struct br2684_vcc *brvcc;
+
+	DPRINTK("br2684_start_xmit, skb->dst=%p\n", skb->dst);
+	read_lock(&devs_lock);
+	brvcc = pick_outgoing_vcc(skb, brdev);
+	if (brvcc == NULL) {
+		DPRINTK("no vcc attached to dev %s\n", dev->name);
+		brdev->stats.tx_errors++;
+		brdev->stats.tx_carrier_errors++;
+		/* netif_stop_queue(dev); */
+		dev_kfree_skb(skb);
+		read_unlock(&devs_lock);
+		return -EUNATCH;
+	}
+	if (!br2684_xmit_vcc(skb, brdev, brvcc)) {
+		/*
+		 * We should probably use netif_*_queue() here, but that
+		 * involves added complication.  We need to walk before
+		 * we can run
+		 */
+		/* don't free here! this pointer might be no longer valid!
+		dev_kfree_skb(skb);
+		*/
+		brdev->stats.tx_errors++;
+		brdev->stats.tx_fifo_errors++;
+	}
+	read_unlock(&devs_lock);
+	return 0;
+}
+
+static struct net_device_stats *br2684_get_stats(struct net_device *dev)
+{
+	DPRINTK("br2684_get_stats\n");
+	return &BRPRIV(dev)->stats;
+}
+
+#ifdef FASTER_VERSION
+/*
+ * These mirror eth_header and eth_header_cache.  They are not usually
+ * exported for use in modules, so we grab them from net_device
+ * after ether_setup() is done with it.  Bit of a hack.
+ */
+static int (*my_eth_header)(struct sk_buff *, struct net_device *,
+	unsigned short, void *, void *, unsigned);
+static int (*my_eth_header_cache)(struct neighbour *, struct hh_cache *);
+
+static int
+br2684_header(struct sk_buff *skb, struct net_device *dev,
+	      unsigned short type, void *daddr, void *saddr, unsigned len)
+{
+	u16 *pad_before_eth;
+	int t = my_eth_header(skb, dev, type, daddr, saddr, len);
+	if (t > 0) {
+		pad_before_eth = (u16 *) skb_push(skb, 2);
+		*pad_before_eth = 0;
+		return dev->hard_header_len;	/* or return 16; ? */
+	} else
+		return t;
+}
+
+static int
+br2684_header_cache(struct neighbour *neigh, struct hh_cache *hh)
+{
+/* hh_data is 16 bytes long. if encaps is ether-llc we need 24, so
+xmit will add the additional header part in that case */
+	u16 *pad_before_eth = (u16 *)(hh->hh_data);
+	int t = my_eth_header_cache(neigh, hh);
+	DPRINTK("br2684_header_cache, neigh=%p, hh_cache=%p\n", neigh, hh);
+	if (t < 0)
+		return t;
+	else {
+		*pad_before_eth = 0;
+		hh->hh_len = PADLEN + ETH_HLEN;
+	}
+	return 0;
+}
+
+/*
+ * This is similar to eth_type_trans, which cannot be used because of
+ * our dev->hard_header_len
+ */
+static inline unsigned short br_type_trans(struct sk_buff *skb,
+					       struct net_device *dev)
+{
+	struct ethhdr *eth;
+	unsigned char *rawp;
+	eth = skb->mac.ethernet;
+
+	if (*eth->h_dest & 1) {
+		if (memcmp(eth->h_dest, dev->broadcast, ETH_ALEN) == 0)
+			skb->pkt_type = PACKET_BROADCAST;
+		else
+			skb->pkt_type = PACKET_MULTICAST;
+	}
+
+	else if (memcmp(eth->h_dest, dev->dev_addr, ETH_ALEN))
+		skb->pkt_type = PACKET_OTHERHOST;
+
+	if (ntohs(eth->h_proto) >= 1536)
+		return eth->h_proto;
+
+	rawp = skb->data;
+
+	/*
+	 * This is a magic hack to spot IPX packets. Older Novell breaks
+	 * the protocol design and runs IPX over 802.3 without an 802.2 LLC
+	 * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
+	 * won't work for fault tolerant netware but does for the rest.
+	 */
+	if (*(unsigned short *) rawp == 0xFFFF)
+		return htons(ETH_P_802_3);
+
+	/*
+	 * Real 802.2 LLC
+	 */
+	return htons(ETH_P_802_2);
+}
+#endif /* FASTER_VERSION */
+
+/*
+ * We remember when the MAC gets set, so we don't override it later with
+ * the ESI of the ATM card of the first VC
+ */
+static int (*my_eth_mac_addr)(struct net_device *, void *);
+static int br2684_mac_addr(struct net_device *dev, void *p)
+{
+	int err = my_eth_mac_addr(dev, p);
+	if (!err)
+		BRPRIV(dev)->mac_was_set = 1;
+	return err;
+}
+
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+/* this IOCTL is experimental. */
+static int br2684_setfilt(struct atm_vcc *atmvcc, unsigned long arg)
+{
+	struct br2684_vcc *brvcc;
+	struct br2684_filter_set fs;
+
+	if (copy_from_user(&fs, (void *) arg, sizeof fs))
+		return -EFAULT;
+	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
+		/*
+		 * This is really a per-vcc thing, but we can also search
+		 * by device
+		 */
+		struct br2684_dev *brdev;
+		read_lock(&devs_lock);
+		brdev = br2684_find_dev(&fs.ifspec);
+		if (brdev == NULL || list_empty(&brdev->brvccs) ||
+		    brdev->brvccs.next != brdev->brvccs.prev)  /* >1 VCC */
+			brvcc = NULL;
+		else
+			brvcc = list_entry_brvcc(brdev->brvccs.next);
+		read_unlock(&devs_lock);
+		if (brvcc == NULL)
+			return -ESRCH;
+	} else
+		brvcc = BR2684_VCC(atmvcc);
+	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
+	return 0;
+}
+
+/* Returns 1 if packet should be dropped */
+static inline int
+packet_fails_filter(u16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
+{
+	if (brvcc->filter.netmask == 0)
+		return 0;			/* no filter in place */
+	if (type == __constant_htons(ETH_P_IP) &&
+	    (((struct iphdr *) (skb->data))->daddr & brvcc->filter.
+	     netmask) == brvcc->filter.prefix)
+		return 0;
+	if (type == __constant_htons(ETH_P_ARP))
+		return 0;
+	/* TODO: we should probably filter ARPs too.. don't want to have
+	 *   them returning values that don't make sense, or is that ok?
+	 */
+	return 1;		/* drop */
+}
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+
+static void br2684_close_vcc(struct br2684_vcc *brvcc)
+{
+	DPRINTK("removing VCC %p from dev %p\n", brvcc, brvcc->brdev);
+	write_lock_irq(&devs_lock);
+	list_del(&brvcc->brvccs);
+	write_unlock_irq(&devs_lock);
+	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
+	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
+	kfree(brvcc);
+	MOD_DEC_USE_COUNT;
+}
+
+/* when AAL5 PDU comes in: */
+static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
+{
+	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
+	struct br2684_dev *brdev = brvcc->brdev;
+	int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN;
+
+	DPRINTK("br2684_push\n");
+
+	if (skb == NULL) {	/* skb==NULL means VCC is being destroyed */
+		br2684_close_vcc(brvcc);
+		if (list_empty(&brdev->brvccs)) {
+			read_lock(&devs_lock);
+			list_del(&brdev->br2684_devs);
+			read_unlock(&devs_lock);
+			unregister_netdev(&brdev->net_dev);
+			kfree(brdev);
+		}
+		return;
+	}
+
+	skb_debug(skb);
+	atm_return(atmvcc, skb->truesize);
+	DPRINTK("skb from brdev %p\n", brdev);
+	if (brvcc->encaps == e_llc) {
+		/* let us waste some time for checking the encapsulation.
+		   Note, that only 7 char is checked so frames with a valid FCS
+		   are also accepted (but FCS is not checked of course) */
+		if (memcmp(skb->data, llc_oui_pid_pad, 7)) {
+			brdev->stats.rx_errors++;
+			dev_kfree_skb(skb);
+			return;
+		}
+	} else {
+		plen = PADLEN + ETH_HLEN;	/* pad, dstmac,srcmac, ethtype */
+		/* first 2 chars should be 0 */
+		if (*((u16 *) (skb->data)) != 0) {
+			brdev->stats.rx_errors++;
+			dev_kfree_skb(skb);
+			return;
+		}
+	}
+	if (skb->len < plen) {
+		brdev->stats.rx_errors++;
+		dev_kfree_skb(skb);	/* dev_ not needed? */
+		return;
+	}
+
+#ifdef FASTER_VERSION
+	/* FIXME: tcpdump shows that pointer to mac header is 2 bytes earlier,
+	   than should be. What else should I set? */
+	skb_pull(skb, plen);
+	skb->mac.raw = ((char *) (skb->data)) - ETH_HLEN;
+	skb->pkt_type = PACKET_HOST;
+#ifdef CONFIG_BR2684_FAST_TRANS
+	skb->protocol = ((u16 *) skb->data)[-1];
+#else				/* some protocols might require this: */
+	skb->protocol = br_type_trans(skb, &brdev->net_dev);
+#endif /* CONFIG_BR2684_FAST_TRANS */
+#else
+	skb_pull(skb, plen - ETH_HLEN);
+	skb->protocol = eth_type_trans(skb, &brdev->net_dev);
+#endif /* FASTER_VERSION */
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	if (packet_fails_filter(skb->protocol, brvcc, skb)) {
+		brdev->stats.rx_dropped++;
+		dev_kfree_skb(skb);
+		return;
+	}
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+	skb->dev = &brdev->net_dev;
+	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
+	DPRINTK("received packet's protocol: %x\n", ntohs(skb->protocol));
+	skb_debug(skb);
+	if (!(brdev->net_dev.flags & IFF_UP)) { /* sigh, interface is down */
+		brdev->stats.rx_dropped++;
+		dev_kfree_skb(skb);
+		return;
+	}
+	brdev->stats.rx_packets++;
+	brdev->stats.rx_bytes += skb->len;
+	netif_rx(skb);
+}
+
+static int br2684_regvcc(struct atm_vcc *atmvcc, unsigned long arg)
+{
+/* assign a vcc to a dev
+Note: we do not have explicit unassign, but look at _push()
+*/
+	int err;
+	struct br2684_vcc *brvcc;
+	struct sk_buff_head copy;
+	struct sk_buff *skb;
+	struct br2684_dev *brdev;
+	struct atm_backend_br2684 be;
+
+	MOD_INC_USE_COUNT;
+	if (copy_from_user(&be, (void *) arg, sizeof be)) {
+		MOD_DEC_USE_COUNT;
+		return -EFAULT;
+	}
+	write_lock_irq(&devs_lock);
+	brdev = br2684_find_dev(&be.ifspec);
+	if (brdev == NULL) {
+		printk(KERN_ERR
+		    "br2684: tried to attach to non-existant device\n");
+		err = -ENXIO;
+		goto error;
+	}
+	if (atmvcc->push == NULL) {
+		err = -EBADFD;
+		goto error;
+	}
+	if (!list_empty(&brdev->brvccs)) {	/* Only 1 VCC/dev right now */
+		err = -EEXIST;
+		goto error;
+	}
+	if (be.fcs_in != BR2684_FCSIN_NO || be.fcs_out != BR2684_FCSOUT_NO ||
+	    be.fcs_auto || be.has_vpiid || be.send_padding || (be.encaps !=
+	    BR2684_ENCAPS_VC && be.encaps != BR2684_ENCAPS_LLC) ||
+	    be.min_size != 0) {
+		err = -EINVAL;
+		goto error;
+	}
+	brvcc = kmalloc(sizeof(struct br2684_vcc), GFP_KERNEL);
+	if (!brvcc) {
+		err = -ENOMEM;
+		goto error;
+	}
+	memset(brvcc, 0, sizeof(struct br2684_vcc));
+	DPRINTK("br2684_regvcc vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps,
+		brvcc);
+	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
+		unsigned char *esi = atmvcc->dev->esi;
+		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
+			memcpy(brdev->net_dev.dev_addr, esi,
+			    brdev->net_dev.addr_len);
+		else
+			brdev->net_dev.dev_addr[2] = 1;
+	}
+	list_add(&brvcc->brvccs, &brdev->brvccs);
+	write_unlock_irq(&devs_lock);
+	brvcc->brdev = brdev;
+	brvcc->atmvcc = atmvcc;
+	atmvcc->user_back = brvcc;
+	brvcc->encaps = (enum br2684_encaps) be.encaps;
+	brvcc->old_push = atmvcc->push;
+	barrier();
+	atmvcc->push = br2684_push;
+	skb_queue_head_init(&copy);
+	skb_migrate(&atmvcc->sk->receive_queue, &copy);
+	while ((skb = skb_dequeue(&copy))) {
+		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
+		BRPRIV(skb->dev)->stats.rx_packets--;
+		br2684_push(atmvcc, skb);
+	}
+	return 0;
+    error:
+	write_unlock_irq(&devs_lock);
+	MOD_DEC_USE_COUNT;
+	return err;
+}
+
+static int br2684_create(unsigned long arg)
+{
+	int err;
+	struct br2684_dev *brdev;
+	struct atm_newif_br2684 ni;
+
+	DPRINTK("br2684_create\n");
+	/*
+	 * We track module use by vcc's NOT the devices they're on.  We're
+	 * protected here against module death by the kernel_lock, but if
+	 * we need to sleep we should make sure that the module doesn't
+	 * disappear under us.
+	 */
+	MOD_INC_USE_COUNT;
+	if (copy_from_user(&ni, (void *) arg, sizeof ni)) {
+		MOD_DEC_USE_COUNT;
+		return -EFAULT;
+	}
+	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
+		MOD_DEC_USE_COUNT;
+		return -EINVAL;
+	}
+	if ((brdev = kmalloc(sizeof(struct br2684_dev), GFP_KERNEL)) == NULL) {
+		MOD_DEC_USE_COUNT;
+		return -ENOMEM;
+	}
+	memset(brdev, 0, sizeof(struct br2684_dev));
+	INIT_LIST_HEAD(&brdev->brvccs);
+
+	write_lock_irq(&devs_lock);
+	brdev->number = list_empty(&br2684_devs) ? 1 :
+	    list_entry_brdev(br2684_devs.prev)->number + 1;
+	list_add_tail(&brdev->br2684_devs, &br2684_devs);
+	write_unlock_irq(&devs_lock);
+
+	if (ni.ifname[0] != '\0') {
+		memcpy(brdev->net_dev.name, ni.ifname,
+		    sizeof(brdev->net_dev.name));
+		brdev->net_dev.name[sizeof(brdev->net_dev.name) - 1] = '\0';
+	} else
+		sprintf(brdev->net_dev.name, "nas%d", brdev->number);
+	DPRINTK("registered netdev %s\n", brdev->net_dev.name);
+	ether_setup(&brdev->net_dev);
+	brdev->mac_was_set = 0;
+#ifdef FASTER_VERSION
+	my_eth_header = brdev->net_dev.hard_header;
+	brdev->net_dev.hard_header = br2684_header;
+	my_eth_header_cache = brdev->net_dev.hard_header_cache;
+	brdev->net_dev.hard_header_cache = br2684_header_cache;
+	brdev->net_dev.hard_header_len = sizeof(llc_oui_pid_pad) + ETH_HLEN;	/* 10 + 14 */
+#endif
+	my_eth_mac_addr = brdev->net_dev.set_mac_address;
+	brdev->net_dev.set_mac_address = br2684_mac_addr;
+	brdev->net_dev.hard_start_xmit = br2684_start_xmit;
+	brdev->net_dev.get_stats = br2684_get_stats;
+
+	/* open, stop, do_ioctl ? */
+	err = register_netdev(&brdev->net_dev);
+	MOD_DEC_USE_COUNT;
+	if (err < 0) {
+		printk(KERN_ERR "br2684_create: register_netdev failed\n");
+		write_lock_irq(&devs_lock);
+		list_del(&brdev->br2684_devs);
+		write_unlock_irq(&devs_lock);
+		kfree(brdev);
+		return err;
+	}
+	return 0;
+}
+
+/*
+ * This handles ioctls actually performed on our vcc - we must return
+ * -ENOIOCTLCMD for any unrecognized ioctl
+ */
+static int br2684_ioctl(struct atm_vcc *atmvcc, unsigned int cmd,
+	unsigned long arg)
+{
+	int err;
+	switch(cmd) {
+	case ATM_SETBACKEND:
+	case ATM_NEWBACKENDIF: {
+		atm_backend_t b;
+		MOD_INC_USE_COUNT;
+		err = get_user(b, (atm_backend_t *) arg);
+		MOD_DEC_USE_COUNT;
+		if (err)
+			return -EFAULT;
+		if (b != ATM_BACKEND_BR2684)
+			return -ENOIOCTLCMD;
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (cmd == ATM_SETBACKEND)
+			return br2684_regvcc(atmvcc, arg);
+		else
+			return br2684_create(arg);
+		}
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	case BR2684_SETFILT:
+		if (atmvcc->push != br2684_push)
+			return -ENOIOCTLCMD;
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		MOD_INC_USE_COUNT;
+		err = br2684_setfilt(atmvcc, arg);
+		MOD_DEC_USE_COUNT;
+		return err;
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+	}
+	return -ENOIOCTLCMD;
+}
+
+/* Never put more than 256 bytes in at once */
+static int br2684_proc_engine(loff_t pos, char *buf)
+{
+	struct list_head *lhd, *lhc;
+	struct br2684_dev *brdev;
+	struct br2684_vcc *brvcc;
+	list_for_each(lhd, &br2684_devs) {
+		brdev = list_entry_brdev(lhd);
+		if (pos-- == 0)
+			return sprintf(buf, "dev %.16s: num=%d, mac=%02X:%02X:"
+			    "%02X:%02X:%02X:%02X (%s)\n", brdev->net_dev.name,
+			    brdev->number,
+			    brdev->net_dev.dev_addr[0],
+			    brdev->net_dev.dev_addr[1],
+			    brdev->net_dev.dev_addr[2],
+			    brdev->net_dev.dev_addr[3],
+			    brdev->net_dev.dev_addr[4],
+			    brdev->net_dev.dev_addr[5],
+			    brdev->mac_was_set ? "set" : "auto");
+		list_for_each(lhc, &brdev->brvccs) {
+			brvcc = list_entry_brvcc(lhc);
+			if (pos-- == 0)
+				return sprintf(buf, "  vcc %d.%d.%d: encaps=%s"
+#ifndef FASTER_VERSION
+				    ", failed copies %u/%u"
+#endif /* FASTER_VERSION */
+				    "\n", brvcc->atmvcc->dev->number,
+				    brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
+				    (brvcc->encaps == e_llc) ? "LLC" : "VC"
+#ifndef FASTER_VERSION
+				    , brvcc->copies_failed
+				    , brvcc->copies_needed
+#endif /* FASTER_VERSION */
+				    );
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+#define b1(var, byte)	((u8 *) &brvcc->filter.var)[byte]
+#define bs(var)		b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)
+			if (brvcc->filter.netmask != 0 && pos-- == 0)
+				return sprintf(buf, "    filter=%d.%d.%d.%d/"
+				    "%d.%d.%d.%d\n", bs(prefix), bs(netmask));
+#undef bs
+#undef b1
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+		}
+	}
+	return 0;
+}
+
+static ssize_t br2684_proc_read(struct file *file, char *buf, size_t count,
+	loff_t *pos)
+{
+	unsigned long page;
+	int len = 0, x, left;
+	page = get_zeroed_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+	left = PAGE_SIZE - 256;
+	if (count < left)
+		left = count;
+	read_lock(&devs_lock);
+	for (;;) {
+		x = br2684_proc_engine(*pos, &((char *) page)[len]);
+		if (x == 0)
+			break;
+		if (x > left)
+			/*
+			 * This should only happen if the user passed in
+			 * a "count" too small for even one line
+			 */
+			x = -EINVAL;
+		if (x < 0) {
+			len = x;
+			break;
+		}
+		len += x;
+		left -= x;
+		(*pos)++;
+		if (left < 256)
+			break;
+	}
+	read_unlock(&devs_lock);
+	if (len > 0 && copy_to_user(buf, (char *) page, len))
+		len = -EFAULT;
+	free_page(page);
+	return len;
+}
+
+static struct file_operations br2684_proc_operations = {
+	read: br2684_proc_read,
+};
+
+extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
+
+extern int (*br2684_ioctl_hook)(struct atm_vcc *, unsigned int, unsigned long);
+
+/* the following avoids some spurious warnings from the compiler */
+#define UNUSED __attribute__((unused))
+
+static int __init UNUSED br2684_init(void)
+{
+	struct proc_dir_entry *p;
+	if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
+		return -ENOMEM;
+	p->proc_fops = &br2684_proc_operations;
+	br2684_ioctl_hook = br2684_ioctl;
+	return 0;
+}
+
+static void __exit UNUSED br2684_exit(void)
+{
+	struct br2684_dev *brdev;
+	br2684_ioctl_hook = NULL;
+	remove_proc_entry("br2684", atm_proc_root);
+	while (!list_empty(&br2684_devs)) {
+		brdev = list_entry_brdev(br2684_devs.next);
+		unregister_netdev(&brdev->net_dev);
+		list_del(&brdev->br2684_devs);
+		kfree(brdev);
+	}
+}
+
+module_init(br2684_init);
+module_exit(br2684_exit);
+
+MODULE_AUTHOR("Marcell GAL");
+MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
+MODULE_LICENSE("GPL");

net/atm/common.c

@@ -62,6 +62,13 @@ int (*pppoatm_ioctl_hook)(struct atm_vcc *, unsigned int, unsigned long);
 EXPORT_SYMBOL(pppoatm_ioctl_hook);
 #endif
 
+#if defined(CONFIG_ATM_BR2684) || defined(CONFIG_ATM_BR2684_MODULE)
+int (*br2684_ioctl_hook)(struct atm_vcc *, unsigned int, unsigned long);
+#ifdef CONFIG_ATM_BR2684_MODULE
+EXPORT_SYMBOL(br2684_ioctl_hook);
+#endif
+#endif
+
 #include "resources.h"		/* atm_find_dev */
 #include "common.h"		/* prototypes */
 #include "protocols.h"		/* atm_init_<transport> */
@@ -784,6 +791,13 @@ int atm_ioctl(struct socket *sock,unsigned int cmd,unsigned long arg)
 		if (ret_val != -ENOIOCTLCMD)
 			goto done;
 	}
+#endif
+#if defined(CONFIG_ATM_BR2684) || defined(CONFIG_ATM_BR2684_MODULE)
+	if (br2684_ioctl_hook) {
+		ret_val = br2684_ioctl_hook(vcc, cmd, arg);
+		if (ret_val != -ENOIOCTLCMD)
+			goto done;
+	}
 #endif
 	if (get_user(buf,&((struct atmif_sioc *) arg)->arg)) {
 		ret_val = -EFAULT;