add support for routed RFC2684 encaps. on ATM (patches written by joseangel), close #58

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@3003 3c298f89-4303-0410-b956-a3cf2f4a3e73

2 files changed, 609 insertions, 0 deletions

diff --git a/target/linux/generic-2.4/patches/225-atm_br2684.patch b/target/linux/generic-2.4/patches/225-atm_br2684.patch
new file mode 100644
index 0000000000..3b01533cd1
--- /dev/null
+++ b/target/linux/generic-2.4/patches/225-atm_br2684.patch
@@ -0,0 +1,600 @@
+diff -Nur linux.old/net/atm/br2684.c linux.new/net/atm/br2684.c
+--- linux.old/net/atm/br2684.c	2004-08-08 01:26:06.000000000 +0200
++++ linux.new/net/atm/br2684.c	2005-11-13 00:04:15.000000000 +0100
+@@ -16,12 +16,9 @@
+ #include <linux/ip.h>
+ #include <asm/uaccess.h>
+ #include <net/arp.h>
+-#include <linux/atm.h>
+-#include <linux/atmdev.h>
+ 
+ #include <linux/atmbr2684.h>
+ 
+-#include "common.h"
+ #include "ipcommon.h"
+ 
+ /*
+@@ -55,36 +52,57 @@
+ #define skb_debug(skb)	do {} while (0)
+ #endif
+ 
++#define	BR2684_LLC_LEN		3
++#define	BR2684_SNAP_LEN		3
++#define	BR2684_ETHERTYPE_LEN	2
++#define	BR2684_PID_LEN		2
++#define	BR2684_PAD_LEN		2
++
++static unsigned char llc_common[] = { 0xaa, 0xaa, 0x03 };
++static unsigned char snap_bridged[] = { 0x00, 0x80, 0xc2 };
++static unsigned char snap_routed[] = { 0x00, 0x00, 0x00 };
++static unsigned char pid_ipv4[] = { 0x00, 0x07 };
++static unsigned char ethertype_ipv4[] = { 0x08, 0x00 };
++static unsigned char ethertype_ipv6[] = { 0x86, 0xdd };
++static unsigned char pad_bridged[] = { 0x00, 0x00 };
++
+ static unsigned char llc_oui_pid_pad[] =
+     { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
++static unsigned char llc_oui_ipv6[] =
++    { 0xAA, 0xAA, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd };
++static unsigned char llc_oui_ipv4[] =
++    { 0xAA, 0xAA, 0x03, 0x00, 0x00, 0x00, 0x08, 0x00 };
+ #define PADLEN	(2)
+ 
+ enum br2684_encaps {
+-	e_vc  = BR2684_ENCAPS_VC,
++	e_vc = BR2684_ENCAPS_VC,
+ 	e_llc = BR2684_ENCAPS_LLC,
+ };
+ 
++
++
+ struct br2684_vcc {
+-	struct atm_vcc  *atmvcc;
++	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_push) (struct atm_vcc * vcc, struct sk_buff * skb);
+ 	/* void (*old_pop)(struct atm_vcc *vcc,struct sk_buff *skb); */
+ 	enum br2684_encaps encaps;
++	enum br2684_payload payload;
+ 	struct list_head brvccs;
+ #ifdef CONFIG_ATM_BR2684_IPFILTER
+ 	struct br2684_filter filter;
+-#endif /* CONFIG_ATM_BR2684_IPFILTER */
++#endif				/* CONFIG_ATM_BR2684_IPFILTER */
+ #ifndef FASTER_VERSION
+ 	unsigned copies_needed, copies_failed;
+-#endif /* FASTER_VERSION */
++#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 list_head brvccs;	/* one device <=> one vcc (before xmas) */
+ 	struct net_device_stats stats;
+ 	int mac_was_set;
+ };
+@@ -173,24 +197,84 @@
+ 		}
+ 		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 */
++
++	/* This skb_push is a problem: routed packets need less headroom than
++	 * bridged packets.
++	 */
++
++/*	skb_push(skb, minheadroom); */
++	if (brvcc->encaps == e_llc) {
++		int offset = 0;
++		int actual_headroom;
++
++		actual_headroom =
++		    BR2684_LLC_LEN +
++		    BR2684_SNAP_LEN +
++		    ((brvcc->payload == p_bridged) ?
++		     (BR2684_PID_LEN + BR2684_PAD_LEN) :
++		     BR2684_ETHERTYPE_LEN);
++
++		skb_push(skb, actual_headroom);
++		memcpy(skb->data, llc_common, BR2684_LLC_LEN);
++		offset += BR2684_LLC_LEN;
++
++		if (brvcc->payload == p_bridged) {
++			memcpy(skb->data + offset, snap_bridged,
++			       BR2684_SNAP_LEN);
++			offset += BR2684_SNAP_LEN;
++			/* pid_ipv4 is poorly named.  should probably be
++			 * pid_ethernet
++			 */
++			memcpy(skb->data + offset, pid_ipv4,
++			       BR2684_PID_LEN);
++			offset += BR2684_PID_LEN;
++			memcpy(skb->data + offset, pad_bridged,
++			       BR2684_PAD_LEN);
++			offset += BR2684_PAD_LEN;
++		} else if (brvcc->payload == p_routed) {
++			unsigned short prot =
++			    __constant_ntohs(skb->protocol);
++			memcpy(skb->data + offset, snap_routed,
++			       BR2684_SNAP_LEN);
++			offset += BR2684_SNAP_LEN;
++
++			switch (prot) {
++			case ETH_P_IP:
++				memcpy(skb->data + offset,
++				       ethertype_ipv4,
++				       BR2684_ETHERTYPE_LEN);
++				break;
++			case ETH_P_IPV6:
++				memcpy(skb->data + offset,
++				       ethertype_ipv6,
++				       BR2684_ETHERTYPE_LEN);
++				break;
++			default:
++				dev_kfree_skb(skb);
++				return 0;
++			}
++			offset += BR2684_ETHERTYPE_LEN;
++
++		}
++	} else {
++		skb_push(skb, 2);
++		if (brvcc->payload == p_bridged)
++			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);
++	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.
+-		*/
++		   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++;
+@@ -428,18 +512,39 @@
+ 	atm_return(atmvcc, skb->truesize);
+ 	DPRINTK("skb from brdev %p\n", brdev);
+ 	if (brvcc->encaps == e_llc) {
++		/* accept packets that have "ipv[46]" in the snap header */
++		/* 8 - 2 == sizeof(llc_oui_ipv6) - BR2684_ETHERTYPE_LEN */
++		if (memcmp(skb->data, llc_oui_ipv6, 8 - 2) == 0) {
++			plen = sizeof(llc_oui_ipv6);
++
++			if (memcmp(skb->data + 6, ethertype_ipv6, 2) == 0)
++				skb->protocol =
++				    __constant_htons(ETH_P_IPV6);
++			else if (memcmp(skb->data + 6, ethertype_ipv4, 2)
++				 == 0)
++				skb->protocol = __constant_htons(ETH_P_IP);
++			else {
++				brdev->stats.rx_errors++;
++				dev_kfree_skb(skb);
++				return;
++			}
++			skb_pull(skb, plen);
++			skb->nh.raw = skb->data;
++			skb->pkt_type = PACKET_HOST;
++		}
++
+ 		/* 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)) {
++		else if (memcmp(skb->data, llc_oui_pid_pad, 7) == 0) {
++			skb_pull(skb, plen - ETH_HLEN);
++			skb->protocol =
++			    eth_type_trans(skb, &brdev->net_dev);
++		} else {
+ 			brdev->stats.rx_errors++;
+ 			dev_kfree_skb(skb);
+ 			return;
+ 		}
+-
+-		/* Strip FCS if present */
+-		if (skb->len > 7 && skb->data[7] == 0x01)
+-			__skb_trim(skb, skb->len - 4);
+ 	} else {
+ 		plen = PADLEN + ETH_HLEN;	/* pad, dstmac,srcmac, ethtype */
+ 		/* first 2 chars should be 0 */
+@@ -448,13 +553,14 @@
+ 			dev_kfree_skb(skb);
+ 			return;
+ 		}
++		skb_pull(skb, plen - ETH_HLEN);
++		skb->protocol = eth_type_trans(skb, &brdev->net_dev);
+ 	}
+ 	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? */
+@@ -465,30 +571,29 @@
+ 	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 */
++#endif				/* CONFIG_BR2684_FAST_TRANS */
+ #else
+-	skb_pull(skb, plen - ETH_HLEN);
+-	skb->protocol = eth_type_trans(skb, &brdev->net_dev);
+-#endif /* FASTER_VERSION */
++	/* 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 */
++#endif				/* CONFIG_ATM_BR2684_IPFILTER */
+ 	skb->dev = &brdev->net_dev;
+-	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
++	/* 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 */
++	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;
+-	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
+ 	netif_rx(skb);
+ }
+ 
+@@ -525,10 +630,10 @@
+ 		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) {
++	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;
+ 	}
+@@ -554,18 +659,21 @@
+ 	brvcc->atmvcc = atmvcc;
+ 	atmvcc->user_back = brvcc;
+ 	brvcc->encaps = (enum br2684_encaps) be.encaps;
++	brvcc->payload = (enum br2684_payload) be.payload;
+ 	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))) {
++#ifdef notdef
+ 		BRPRIV(skb->dev)->stats.rx_bytes -= skb->len;
+ 		BRPRIV(skb->dev)->stats.rx_packets--;
++#endif
+ 		br2684_push(atmvcc, skb);
+ 	}
+ 	return 0;
+-    error:
++      error:
+ 	write_unlock_irq(&devs_lock);
+ 	MOD_DEC_USE_COUNT;
+ 	return err;
+@@ -608,12 +717,25 @@
+ 
+ 	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';
++		       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);
++	if (ni.payload == p_routed) {
++		brdev->net_dev.hard_header_len = 0;
++		brdev->net_dev.addr_len = 0;
++		brdev->net_dev.mtu = 1500;
++
++		/* Type PPP seems most suitable */
++		brdev->net_dev.type = ARPHRD_PPP;
++		brdev->net_dev.flags =
++		    IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
++		brdev->net_dev.tx_queue_len = 100;
++	} else {
++		ether_setup(&brdev->net_dev);
++	}
+ 	brdev->mac_was_set = 0;
+ #ifdef FASTER_VERSION
+ 	my_eth_header = brdev->net_dev.hard_header;
+@@ -677,12 +799,11 @@
+ 		err = br2684_setfilt(atmvcc, arg);
+ 		MOD_DEC_USE_COUNT;
+ 		return err;
+-#endif /* CONFIG_ATM_BR2684_IPFILTER */
++#endif				/* CONFIG_ATM_BR2684_IPFILTER */
+ 	}
+ 	return -ENOIOCTLCMD;
+ }
+ 
+-#ifdef CONFIG_PROC_FS
+ /* Never put more than 256 bytes in at once */
+ static int br2684_proc_engine(loff_t pos, char *buf)
+ {
+@@ -692,52 +813,62 @@
+ 	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");
++			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"
++				return sprintf(buf,
++					       "  vcc %d.%d.%d: encaps=%s"
++					       ", payload=%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"
++					       ", failed copies %u/%u"
++#endif				/* FASTER_VERSION */
++					       "\n",
++					       brvcc->atmvcc->dev->number,
++					       brvcc->atmvcc->vpi,
++					       brvcc->atmvcc->vci,
++					       (brvcc->encaps ==
++						e_llc) ? "LLC" : "VC",
++					       (brvcc->payload ==
++						p_bridged) ? "bridged" :
++					       "routed"
+ #ifndef FASTER_VERSION
+-				    , brvcc->copies_failed
+-				    , brvcc->copies_needed
+-#endif /* 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));
++				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 */
++#endif				/* CONFIG_ATM_BR2684_IPFILTER */
+ 		}
+ 	}
+ 	return 0;
+ }
+ 
+ static ssize_t br2684_proc_read(struct file *file, char *buf, size_t count,
+-	loff_t *pos)
++				loff_t * pos)
+ {
+ 	unsigned long page;
+ 	int len = 0, x, left;
+-	loff_t n = *pos;
+-
+ 	page = get_free_page(GFP_KERNEL);
+ 	if (!page)
+ 		return -ENOMEM;
+@@ -746,7 +877,7 @@
+ 		left = count;
+ 	read_lock(&devs_lock);
+ 	for (;;) {
+-		x = br2684_proc_engine(n, &((char *) page)[len]);
++		x = br2684_proc_engine(*pos, &((char *) page)[len]);
+ 		if (x == 0)
+ 			break;
+ 		if (x > left)
+@@ -761,12 +892,11 @@
+ 		}
+ 		len += x;
+ 		left -= x;
+-		n++;
++		(*pos)++;
+ 		if (left < 256)
+ 			break;
+ 	}
+ 	read_unlock(&devs_lock);
+-	*pos = n;
+ 	if (len > 0 && copy_to_user(buf, (char *) page, len))
+ 		len = -EFAULT;
+ 	free_page(page);
+@@ -774,34 +904,32 @@
+ }
+ 
+ static struct file_operations br2684_proc_operations = {
+-	read: br2684_proc_read,
++      read:br2684_proc_read,
+ };
+ 
+ extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
+-#endif /* CONFIG_PROC_FS */
++
++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)
+ {
+-#ifdef CONFIG_PROC_FS
+ 	struct proc_dir_entry *p;
+ 	if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
+ 		return -ENOMEM;
+ 	p->proc_fops = &br2684_proc_operations;
+-#endif /* CONFIG_PROC_FS */
+-	br2684_ioctl_set(br2684_ioctl);
++	br2684_ioctl_hook = br2684_ioctl;
+ 	return 0;
+ }
+ 
+ static void __exit UNUSED br2684_exit(void)
+ {
+ 	struct br2684_dev *brdev;
+-	br2684_ioctl_set(NULL);
+-#ifdef CONFIG_PROC_FS
++	br2684_ioctl_hook = NULL;
+ 	remove_proc_entry("br2684", atm_proc_root);
+-#endif /* CONFIG_PROC_FS */
+ 	while (!list_empty(&br2684_devs)) {
+ 		brdev = list_entry_brdev(br2684_devs.next);
+ 		unregister_netdev(&brdev->net_dev);
+diff -Nur linux.old/net/atm/common.c linux.new/net/atm/common.c
+--- linux.old/net/atm/common.c	2004-02-18 14:36:32.000000000 +0100
++++ linux.new/net/atm/common.c	2005-11-13 00:46:11.000000000 +0100
+@@ -158,6 +158,7 @@
+ }
+ #ifdef CONFIG_ATM_BR2684_MODULE
+ EXPORT_SYMBOL(br2684_ioctl_set);
++EXPORT_SYMBOL(br2684_ioctl_hook);
+ #endif
+ #endif
+
+diff -Nur linux.old/include/linux/atmbr2684.h linux.new/include/linux/atmbr2684.h
+--- linux.old/include/linux/atmbr2684.h	2005-11-13 00:28:19.000000000 +0100
++++ linux.new/include/linux/atmbr2684.h	2005-11-13 00:06:42.000000000 +0100
+@@ -3,6 +3,7 @@
+ 
+ #include <linux/atm.h>
+ #include <linux/if.h>		/* For IFNAMSIZ */
++#include <linux/if_ether.h>	/* ETH_P_* */
+ 
+ /*
+  * Type of media we're bridging (ethernet, token ring, etc)  Currently only
+@@ -36,15 +37,24 @@
+ #define BR2684_ENCAPS_AUTODETECT (2)	/* Unsuported */
+ 
+ /*
++ * Is this VC bridged or routed?
++ */
++
++#define	BR2684_PAYLOAD_ROUTED	(0)
++#define	BR2684_PAYLOAD_BRIDGED	(1)
++
++
++/*
+  * 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;
++	atm_backend_t backend_num;	/* ATM_BACKEND_BR2684 */
++	int media;		/* BR2684_MEDIA_* */
++	char ifname[IFNAMSIZ];
++	int mtu;
++	int payload;		/* bridged or routed */
+ };
+ 
+ /*
+@@ -68,16 +78,17 @@
+  * is per-backend specific
+  */
+ struct atm_backend_br2684 {
+-	atm_backend_t	backend_num;	/* 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 */
++	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 payload;		/* BR2684_PAYLOAD_* */
++	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 */
+ };
+ 
+ /*
+@@ -95,7 +106,12 @@
+ 	struct br2684_filter filter;
+ };
+ 
++enum br2684_payload {
++	p_routed = BR2684_PAYLOAD_ROUTED,
++	p_bridged = BR2684_PAYLOAD_BRIDGED,
++};
++
+ #define BR2684_SETFILT	_IOW( 'a', ATMIOC_BACKEND + 0, \
+ 				struct br2684_filter_set)
+ 
+-#endif /* _LINUX_ATMBR2684_H */
++#endif				/* _LINUX_ATMBR2684_H */
diff --git a/target/linux/image/ar7/Makefile b/target/linux/image/ar7/Makefile
index f5ad6cc660..0b73787854 100644
--- a/target/linux/image/ar7/Makefile
+++ b/target/linux/image/ar7/Makefile
@@ -27,6 +27,15 @@ $(PKG_BUILD_DIR)/ld.script: src/ld.script.in
 	sed -e 's/@@OUTPUT_FORMAT@@/$(OUTPUT_FORMAT)/' \
 	    -e 's/@@LOADADDR@@/$(LOADADDR)/' <$< >$@
 
+$(PKG_BUILD_DIR)/cksum.o: $(PKG_BUILD_DIR)/cksum.c
+	$(HOSTCC) -o $@ $<
+
+$(PKG_BUILD_DIR)/ckmain.o: $(PKG_BUILD_DIR)/ckmain.c
+	$(HOSTCC) -o $@ $<
+
+$(PKG_BUILD_DIR)/tichksum: $(PKG_BUILD_DIR)/ckmain.o $(PKG_BUILD_DIR)/cksum.o
+	$(HOSTCC) -o $@ $<
+
 $(PKG_BUILD_DIR)/LzmaDecode.o: src/LzmaDecode.c
 	$(TARGET_CC) $(CFLAGS) -c -o $@ $<