3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
7 * Bart De Schuymer <bdschuym@pandora.be>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
14 * Lennert dedicates this file to Kerstin Wurdinger.
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/slab.h>
21 #include <linux/netdevice.h>
22 #include <linux/skbuff.h>
23 #include <linux/if_arp.h>
24 #include <linux/if_ether.h>
25 #include <linux/if_vlan.h>
26 #include <linux/if_pppox.h>
27 #include <linux/ppp_defs.h>
28 #include <linux/netfilter_bridge.h>
29 #include <linux/netfilter_ipv4.h>
30 #include <linux/netfilter_ipv6.h>
31 #include <linux/netfilter_arp.h>
32 #include <linux/in_route.h>
33 #include <linux/inetdevice.h>
37 #include <net/route.h>
39 #include <asm/uaccess.h>
40 #include "br_private.h"
42 #include <linux/sysctl.h>
45 #define skb_origaddr(skb) (((struct bridge_skb_cb *) \
46 (skb->nf_bridge->data))->daddr.ipv4)
47 #define store_orig_dstaddr(skb) (skb_origaddr(skb) = ip_hdr(skb)->daddr)
48 #define dnat_took_place(skb) (skb_origaddr(skb) != ip_hdr(skb)->daddr)
51 static struct ctl_table_header *brnf_sysctl_header;
52 static int brnf_call_iptables __read_mostly = 1;
53 static int brnf_call_ip6tables __read_mostly = 1;
54 static int brnf_call_arptables __read_mostly = 1;
55 static int brnf_filter_vlan_tagged __read_mostly = 0;
56 static int brnf_filter_pppoe_tagged __read_mostly = 0;
58 #define brnf_call_iptables 1
59 #define brnf_call_ip6tables 1
60 #define brnf_call_arptables 1
61 #define brnf_filter_vlan_tagged 0
62 #define brnf_filter_pppoe_tagged 0
65 static inline __be16 vlan_proto(const struct sk_buff *skb)
67 if (vlan_tx_tag_present(skb))
69 else if (skb->protocol == htons(ETH_P_8021Q))
70 return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
75 #define IS_VLAN_IP(skb) \
76 (vlan_proto(skb) == htons(ETH_P_IP) && \
77 brnf_filter_vlan_tagged)
79 #define IS_VLAN_IPV6(skb) \
80 (vlan_proto(skb) == htons(ETH_P_IPV6) && \
81 brnf_filter_vlan_tagged)
83 #define IS_VLAN_ARP(skb) \
84 (vlan_proto(skb) == htons(ETH_P_ARP) && \
85 brnf_filter_vlan_tagged)
87 static inline __be16 pppoe_proto(const struct sk_buff *skb)
89 return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
90 sizeof(struct pppoe_hdr)));
93 #define IS_PPPOE_IP(skb) \
94 (skb->protocol == htons(ETH_P_PPP_SES) && \
95 pppoe_proto(skb) == htons(PPP_IP) && \
96 brnf_filter_pppoe_tagged)
98 #define IS_PPPOE_IPV6(skb) \
99 (skb->protocol == htons(ETH_P_PPP_SES) && \
100 pppoe_proto(skb) == htons(PPP_IPV6) && \
101 brnf_filter_pppoe_tagged)
103 static void fake_update_pmtu(struct dst_entry *dst, u32 mtu)
107 static u32 *fake_cow_metrics(struct dst_entry *dst, unsigned long old)
112 static struct neighbour *fake_neigh_lookup(const struct dst_entry *dst, const void *daddr)
117 static unsigned int fake_mtu(const struct dst_entry *dst)
119 return dst->dev->mtu;
122 static struct dst_ops fake_dst_ops = {
124 .protocol = cpu_to_be16(ETH_P_IP),
125 .update_pmtu = fake_update_pmtu,
126 .cow_metrics = fake_cow_metrics,
127 .neigh_lookup = fake_neigh_lookup,
132 * Initialize bogus route table used to keep netfilter happy.
133 * Currently, we fill in the PMTU entry because netfilter
134 * refragmentation needs it, and the rt_flags entry because
135 * ipt_REJECT needs it. Future netfilter modules might
136 * require us to fill additional fields.
138 static const u32 br_dst_default_metrics[RTAX_MAX] = {
139 [RTAX_MTU - 1] = 1500,
142 void br_netfilter_rtable_init(struct net_bridge *br)
144 struct rtable *rt = &br->fake_rtable;
146 atomic_set(&rt->dst.__refcnt, 1);
147 rt->dst.dev = br->dev;
148 rt->dst.path = &rt->dst;
149 dst_init_metrics(&rt->dst, br_dst_default_metrics, true);
150 rt->dst.flags = DST_NOXFRM | DST_NOPEER | DST_FAKE_RTABLE;
151 rt->dst.ops = &fake_dst_ops;
154 static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
156 struct net_bridge_port *port;
158 port = br_port_get_rcu(dev);
159 return port ? &port->br->fake_rtable : NULL;
162 static inline struct net_device *bridge_parent(const struct net_device *dev)
164 struct net_bridge_port *port;
166 port = br_port_get_rcu(dev);
167 return port ? port->br->dev : NULL;
170 static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
172 skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
173 if (likely(skb->nf_bridge))
174 atomic_set(&(skb->nf_bridge->use), 1);
176 return skb->nf_bridge;
179 static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
181 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
183 if (atomic_read(&nf_bridge->use) > 1) {
184 struct nf_bridge_info *tmp = nf_bridge_alloc(skb);
187 memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info));
188 atomic_set(&tmp->use, 1);
190 nf_bridge_put(nf_bridge);
196 static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
198 unsigned int len = nf_bridge_encap_header_len(skb);
201 skb->network_header -= len;
204 static inline void nf_bridge_pull_encap_header(struct sk_buff *skb)
206 unsigned int len = nf_bridge_encap_header_len(skb);
209 skb->network_header += len;
212 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb)
214 unsigned int len = nf_bridge_encap_header_len(skb);
216 skb_pull_rcsum(skb, len);
217 skb->network_header += len;
220 static inline void nf_bridge_save_header(struct sk_buff *skb)
222 int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
224 skb_copy_from_linear_data_offset(skb, -header_size,
225 skb->nf_bridge->data, header_size);
228 static inline void nf_bridge_update_protocol(struct sk_buff *skb)
230 if (skb->nf_bridge->mask & BRNF_8021Q)
231 skb->protocol = htons(ETH_P_8021Q);
232 else if (skb->nf_bridge->mask & BRNF_PPPoE)
233 skb->protocol = htons(ETH_P_PPP_SES);
236 /* When handing a packet over to the IP layer
237 * check whether we have a skb that is in the
241 static int br_parse_ip_options(struct sk_buff *skb)
243 struct ip_options *opt;
244 const struct iphdr *iph;
245 struct net_device *dev = skb->dev;
248 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
252 opt = &(IPCB(skb)->opt);
254 /* Basic sanity checks */
255 if (iph->ihl < 5 || iph->version != 4)
258 if (!pskb_may_pull(skb, iph->ihl*4))
262 if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
265 len = ntohs(iph->tot_len);
266 if (skb->len < len) {
267 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS);
269 } else if (len < (iph->ihl*4))
272 if (pskb_trim_rcsum(skb, len)) {
273 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
277 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
281 opt->optlen = iph->ihl*4 - sizeof(struct iphdr);
282 if (ip_options_compile(dev_net(dev), opt, skb))
285 /* Check correct handling of SRR option */
286 if (unlikely(opt->srr)) {
287 struct in_device *in_dev = __in_dev_get_rcu(dev);
288 if (in_dev && !IN_DEV_SOURCE_ROUTE(in_dev))
291 if (ip_options_rcv_srr(skb))
298 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
303 /* Fill in the header for fragmented IP packets handled by
304 * the IPv4 connection tracking code.
306 int nf_bridge_copy_header(struct sk_buff *skb)
309 unsigned int header_size;
311 nf_bridge_update_protocol(skb);
312 header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
313 err = skb_cow_head(skb, header_size);
317 skb_copy_to_linear_data_offset(skb, -header_size,
318 skb->nf_bridge->data, header_size);
319 __skb_push(skb, nf_bridge_encap_header_len(skb));
323 /* PF_BRIDGE/PRE_ROUTING *********************************************/
324 /* Undo the changes made for ip6tables PREROUTING and continue the
325 * bridge PRE_ROUTING hook. */
326 static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
328 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
331 if (nf_bridge->mask & BRNF_PKT_TYPE) {
332 skb->pkt_type = PACKET_OTHERHOST;
333 nf_bridge->mask ^= BRNF_PKT_TYPE;
335 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
337 rt = bridge_parent_rtable(nf_bridge->physindev);
342 skb_dst_set_noref(skb, &rt->dst);
344 skb->dev = nf_bridge->physindev;
345 nf_bridge_update_protocol(skb);
346 nf_bridge_push_encap_header(skb);
347 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
348 br_handle_frame_finish, 1);
353 /* Obtain the correct destination MAC address, while preserving the original
354 * source MAC address. If we already know this address, we just copy it. If we
355 * don't, we use the neighbour framework to find out. In both cases, we make
356 * sure that br_handle_frame_finish() is called afterwards.
358 static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
360 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
361 struct neighbour *neigh;
362 struct dst_entry *dst;
364 skb->dev = bridge_parent(skb->dev);
368 neigh = dst_get_neighbour(dst);
369 if (neigh->hh.hh_len) {
370 neigh_hh_bridge(&neigh->hh, skb);
371 skb->dev = nf_bridge->physindev;
372 return br_handle_frame_finish(skb);
374 /* the neighbour function below overwrites the complete
375 * MAC header, so we save the Ethernet source address and
376 * protocol number. */
377 skb_copy_from_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN), skb->nf_bridge->data, ETH_HLEN-ETH_ALEN);
378 /* tell br_dev_xmit to continue with forwarding */
379 nf_bridge->mask |= BRNF_BRIDGED_DNAT;
380 return neigh->output(neigh, skb);
387 /* This requires some explaining. If DNAT has taken place,
388 * we will need to fix up the destination Ethernet address.
390 * There are two cases to consider:
391 * 1. The packet was DNAT'ed to a device in the same bridge
392 * port group as it was received on. We can still bridge
394 * 2. The packet was DNAT'ed to a different device, either
395 * a non-bridged device or another bridge port group.
396 * The packet will need to be routed.
398 * The correct way of distinguishing between these two cases is to
399 * call ip_route_input() and to look at skb->dst->dev, which is
400 * changed to the destination device if ip_route_input() succeeds.
402 * Let's first consider the case that ip_route_input() succeeds:
404 * If the output device equals the logical bridge device the packet
405 * came in on, we can consider this bridging. The corresponding MAC
406 * address will be obtained in br_nf_pre_routing_finish_bridge.
407 * Otherwise, the packet is considered to be routed and we just
408 * change the destination MAC address so that the packet will
409 * later be passed up to the IP stack to be routed. For a redirected
410 * packet, ip_route_input() will give back the localhost as output device,
411 * which differs from the bridge device.
413 * Let's now consider the case that ip_route_input() fails:
415 * This can be because the destination address is martian, in which case
416 * the packet will be dropped.
417 * If IP forwarding is disabled, ip_route_input() will fail, while
418 * ip_route_output_key() can return success. The source
419 * address for ip_route_output_key() is set to zero, so ip_route_output_key()
420 * thinks we're handling a locally generated packet and won't care
421 * if IP forwarding is enabled. If the output device equals the logical bridge
422 * device, we proceed as if ip_route_input() succeeded. If it differs from the
423 * logical bridge port or if ip_route_output_key() fails we drop the packet.
425 static int br_nf_pre_routing_finish(struct sk_buff *skb)
427 struct net_device *dev = skb->dev;
428 struct iphdr *iph = ip_hdr(skb);
429 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
433 if (nf_bridge->mask & BRNF_PKT_TYPE) {
434 skb->pkt_type = PACKET_OTHERHOST;
435 nf_bridge->mask ^= BRNF_PKT_TYPE;
437 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
438 if (dnat_took_place(skb)) {
439 if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
440 struct in_device *in_dev = __in_dev_get_rcu(dev);
442 /* If err equals -EHOSTUNREACH the error is due to a
443 * martian destination or due to the fact that
444 * forwarding is disabled. For most martian packets,
445 * ip_route_output_key() will fail. It won't fail for 2 types of
446 * martian destinations: loopback destinations and destination
447 * 0.0.0.0. In both cases the packet will be dropped because the
448 * destination is the loopback device and not the bridge. */
449 if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
452 rt = ip_route_output(dev_net(dev), iph->daddr, 0,
453 RT_TOS(iph->tos), 0);
455 /* - Bridged-and-DNAT'ed traffic doesn't
456 * require ip_forwarding. */
457 if (rt->dst.dev == dev) {
458 skb_dst_set(skb, &rt->dst);
467 if (skb_dst(skb)->dev == dev) {
469 skb->dev = nf_bridge->physindev;
470 nf_bridge_update_protocol(skb);
471 nf_bridge_push_encap_header(skb);
472 NF_HOOK_THRESH(NFPROTO_BRIDGE,
475 br_nf_pre_routing_finish_bridge,
479 memcpy(eth_hdr(skb)->h_dest, dev->dev_addr, ETH_ALEN);
480 skb->pkt_type = PACKET_HOST;
483 rt = bridge_parent_rtable(nf_bridge->physindev);
488 skb_dst_set_noref(skb, &rt->dst);
491 skb->dev = nf_bridge->physindev;
492 nf_bridge_update_protocol(skb);
493 nf_bridge_push_encap_header(skb);
494 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
495 br_handle_frame_finish, 1);
500 /* Some common code for IPv4/IPv6 */
501 static struct net_device *setup_pre_routing(struct sk_buff *skb)
503 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
505 if (skb->pkt_type == PACKET_OTHERHOST) {
506 skb->pkt_type = PACKET_HOST;
507 nf_bridge->mask |= BRNF_PKT_TYPE;
510 nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
511 nf_bridge->physindev = skb->dev;
512 skb->dev = bridge_parent(skb->dev);
513 if (skb->protocol == htons(ETH_P_8021Q))
514 nf_bridge->mask |= BRNF_8021Q;
515 else if (skb->protocol == htons(ETH_P_PPP_SES))
516 nf_bridge->mask |= BRNF_PPPoE;
521 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
522 static int check_hbh_len(struct sk_buff *skb)
524 unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
526 const unsigned char *nh = skb_network_header(skb);
528 int len = (raw[1] + 1) << 3;
530 if ((raw + len) - skb->data > skb_headlen(skb))
537 int optlen = nh[off + 1] + 2;
548 if (nh[off + 1] != 4 || (off & 3) != 2)
550 pkt_len = ntohl(*(__be32 *) (nh + off + 2));
551 if (pkt_len <= IPV6_MAXPLEN ||
552 ipv6_hdr(skb)->payload_len)
554 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
556 if (pskb_trim_rcsum(skb,
557 pkt_len + sizeof(struct ipv6hdr)))
559 nh = skb_network_header(skb);
576 /* Replicate the checks that IPv6 does on packet reception and pass the packet
577 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
578 static unsigned int br_nf_pre_routing_ipv6(unsigned int hook,
580 const struct net_device *in,
581 const struct net_device *out,
582 int (*okfn)(struct sk_buff *))
584 const struct ipv6hdr *hdr;
587 if (skb->len < sizeof(struct ipv6hdr))
590 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
595 if (hdr->version != 6)
598 pkt_len = ntohs(hdr->payload_len);
600 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
601 if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
603 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
606 if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb))
609 nf_bridge_put(skb->nf_bridge);
610 if (!nf_bridge_alloc(skb))
612 if (!setup_pre_routing(skb))
615 skb->protocol = htons(ETH_P_IPV6);
616 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
617 br_nf_pre_routing_finish_ipv6);
622 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
623 * Replicate the checks that IPv4 does on packet reception.
624 * Set skb->dev to the bridge device (i.e. parent of the
625 * receiving device) to make netfilter happy, the REDIRECT
626 * target in particular. Save the original destination IP
627 * address to be able to detect DNAT afterwards. */
628 static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff *skb,
629 const struct net_device *in,
630 const struct net_device *out,
631 int (*okfn)(struct sk_buff *))
633 struct net_bridge_port *p;
634 struct net_bridge *br;
635 __u32 len = nf_bridge_encap_header_len(skb);
637 if (unlikely(!pskb_may_pull(skb, len)))
640 p = br_port_get_rcu(in);
645 if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) ||
646 IS_PPPOE_IPV6(skb)) {
647 if (!brnf_call_ip6tables && !br->nf_call_ip6tables)
650 nf_bridge_pull_encap_header_rcsum(skb);
651 return br_nf_pre_routing_ipv6(hook, skb, in, out, okfn);
654 if (!brnf_call_iptables && !br->nf_call_iptables)
657 if (skb->protocol != htons(ETH_P_IP) && !IS_VLAN_IP(skb) &&
661 nf_bridge_pull_encap_header_rcsum(skb);
663 if (br_parse_ip_options(skb))
666 nf_bridge_put(skb->nf_bridge);
667 if (!nf_bridge_alloc(skb))
669 if (!setup_pre_routing(skb))
671 store_orig_dstaddr(skb);
672 skb->protocol = htons(ETH_P_IP);
674 NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
675 br_nf_pre_routing_finish);
681 /* PF_BRIDGE/LOCAL_IN ************************************************/
682 /* The packet is locally destined, which requires a real
683 * dst_entry, so detach the fake one. On the way up, the
684 * packet would pass through PRE_ROUTING again (which already
685 * took place when the packet entered the bridge), but we
686 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
687 * prevent this from happening. */
688 static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff *skb,
689 const struct net_device *in,
690 const struct net_device *out,
691 int (*okfn)(struct sk_buff *))
693 br_drop_fake_rtable(skb);
697 /* PF_BRIDGE/FORWARD *************************************************/
698 static int br_nf_forward_finish(struct sk_buff *skb)
700 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
701 struct net_device *in;
703 if (skb->protocol != htons(ETH_P_ARP) && !IS_VLAN_ARP(skb)) {
704 in = nf_bridge->physindev;
705 if (nf_bridge->mask & BRNF_PKT_TYPE) {
706 skb->pkt_type = PACKET_OTHERHOST;
707 nf_bridge->mask ^= BRNF_PKT_TYPE;
709 nf_bridge_update_protocol(skb);
711 in = *((struct net_device **)(skb->cb));
713 nf_bridge_push_encap_header(skb);
715 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in,
716 skb->dev, br_forward_finish, 1);
720 /* This is the 'purely bridged' case. For IP, we pass the packet to
721 * netfilter with indev and outdev set to the bridge device,
722 * but we are still able to filter on the 'real' indev/outdev
723 * because of the physdev module. For ARP, indev and outdev are the
725 static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb,
726 const struct net_device *in,
727 const struct net_device *out,
728 int (*okfn)(struct sk_buff *))
730 struct nf_bridge_info *nf_bridge;
731 struct net_device *parent;
737 /* Need exclusive nf_bridge_info since we might have multiple
738 * different physoutdevs. */
739 if (!nf_bridge_unshare(skb))
742 parent = bridge_parent(out);
746 if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) ||
749 else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) ||
755 nf_bridge_pull_encap_header(skb);
757 nf_bridge = skb->nf_bridge;
758 if (skb->pkt_type == PACKET_OTHERHOST) {
759 skb->pkt_type = PACKET_HOST;
760 nf_bridge->mask |= BRNF_PKT_TYPE;
763 if (pf == PF_INET && br_parse_ip_options(skb))
766 /* The physdev module checks on this */
767 nf_bridge->mask |= BRNF_BRIDGED;
768 nf_bridge->physoutdev = skb->dev;
770 skb->protocol = htons(ETH_P_IP);
772 skb->protocol = htons(ETH_P_IPV6);
774 NF_HOOK(pf, NF_INET_FORWARD, skb, bridge_parent(in), parent,
775 br_nf_forward_finish);
780 static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff *skb,
781 const struct net_device *in,
782 const struct net_device *out,
783 int (*okfn)(struct sk_buff *))
785 struct net_bridge_port *p;
786 struct net_bridge *br;
787 struct net_device **d = (struct net_device **)(skb->cb);
789 p = br_port_get_rcu(out);
794 if (!brnf_call_arptables && !br->nf_call_arptables)
797 if (skb->protocol != htons(ETH_P_ARP)) {
798 if (!IS_VLAN_ARP(skb))
800 nf_bridge_pull_encap_header(skb);
803 if (arp_hdr(skb)->ar_pln != 4) {
804 if (IS_VLAN_ARP(skb))
805 nf_bridge_push_encap_header(skb);
808 *d = (struct net_device *)in;
809 NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in,
810 (struct net_device *)out, br_nf_forward_finish);
815 #if defined(CONFIG_NF_CONNTRACK_IPV4) || defined(CONFIG_NF_CONNTRACK_IPV4_MODULE)
816 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
820 if (skb->nfct != NULL && skb->protocol == htons(ETH_P_IP) &&
821 skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu &&
823 if (br_parse_ip_options(skb))
824 /* Drop invalid packet */
826 ret = ip_fragment(skb, br_dev_queue_push_xmit);
828 ret = br_dev_queue_push_xmit(skb);
833 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
835 return br_dev_queue_push_xmit(skb);
839 /* PF_BRIDGE/POST_ROUTING ********************************************/
840 static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff *skb,
841 const struct net_device *in,
842 const struct net_device *out,
843 int (*okfn)(struct sk_buff *))
845 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
846 struct net_device *realoutdev = bridge_parent(skb->dev);
849 if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED))
855 if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) ||
858 else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) ||
864 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
865 * about the value of skb->pkt_type. */
866 if (skb->pkt_type == PACKET_OTHERHOST) {
867 skb->pkt_type = PACKET_HOST;
868 nf_bridge->mask |= BRNF_PKT_TYPE;
871 nf_bridge_pull_encap_header(skb);
872 nf_bridge_save_header(skb);
874 skb->protocol = htons(ETH_P_IP);
876 skb->protocol = htons(ETH_P_IPV6);
878 NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev,
879 br_nf_dev_queue_xmit);
884 /* IP/SABOTAGE *****************************************************/
885 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
886 * for the second time. */
887 static unsigned int ip_sabotage_in(unsigned int hook, struct sk_buff *skb,
888 const struct net_device *in,
889 const struct net_device *out,
890 int (*okfn)(struct sk_buff *))
892 if (skb->nf_bridge &&
893 !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
900 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
901 * br_dev_queue_push_xmit is called afterwards */
902 static struct nf_hook_ops br_nf_ops[] __read_mostly = {
904 .hook = br_nf_pre_routing,
905 .owner = THIS_MODULE,
907 .hooknum = NF_BR_PRE_ROUTING,
908 .priority = NF_BR_PRI_BRNF,
911 .hook = br_nf_local_in,
912 .owner = THIS_MODULE,
914 .hooknum = NF_BR_LOCAL_IN,
915 .priority = NF_BR_PRI_BRNF,
918 .hook = br_nf_forward_ip,
919 .owner = THIS_MODULE,
921 .hooknum = NF_BR_FORWARD,
922 .priority = NF_BR_PRI_BRNF - 1,
925 .hook = br_nf_forward_arp,
926 .owner = THIS_MODULE,
928 .hooknum = NF_BR_FORWARD,
929 .priority = NF_BR_PRI_BRNF,
932 .hook = br_nf_post_routing,
933 .owner = THIS_MODULE,
935 .hooknum = NF_BR_POST_ROUTING,
936 .priority = NF_BR_PRI_LAST,
939 .hook = ip_sabotage_in,
940 .owner = THIS_MODULE,
942 .hooknum = NF_INET_PRE_ROUTING,
943 .priority = NF_IP_PRI_FIRST,
946 .hook = ip_sabotage_in,
947 .owner = THIS_MODULE,
949 .hooknum = NF_INET_PRE_ROUTING,
950 .priority = NF_IP6_PRI_FIRST,
956 int brnf_sysctl_call_tables(ctl_table * ctl, int write,
957 void __user * buffer, size_t * lenp, loff_t * ppos)
961 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
963 if (write && *(int *)(ctl->data))
964 *(int *)(ctl->data) = 1;
968 static ctl_table brnf_table[] = {
970 .procname = "bridge-nf-call-arptables",
971 .data = &brnf_call_arptables,
972 .maxlen = sizeof(int),
974 .proc_handler = brnf_sysctl_call_tables,
977 .procname = "bridge-nf-call-iptables",
978 .data = &brnf_call_iptables,
979 .maxlen = sizeof(int),
981 .proc_handler = brnf_sysctl_call_tables,
984 .procname = "bridge-nf-call-ip6tables",
985 .data = &brnf_call_ip6tables,
986 .maxlen = sizeof(int),
988 .proc_handler = brnf_sysctl_call_tables,
991 .procname = "bridge-nf-filter-vlan-tagged",
992 .data = &brnf_filter_vlan_tagged,
993 .maxlen = sizeof(int),
995 .proc_handler = brnf_sysctl_call_tables,
998 .procname = "bridge-nf-filter-pppoe-tagged",
999 .data = &brnf_filter_pppoe_tagged,
1000 .maxlen = sizeof(int),
1002 .proc_handler = brnf_sysctl_call_tables,
1007 static struct ctl_path brnf_path[] = {
1008 { .procname = "net", },
1009 { .procname = "bridge", },
1014 int __init br_netfilter_init(void)
1018 ret = dst_entries_init(&fake_dst_ops);
1022 ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1024 dst_entries_destroy(&fake_dst_ops);
1027 #ifdef CONFIG_SYSCTL
1028 brnf_sysctl_header = register_sysctl_paths(brnf_path, brnf_table);
1029 if (brnf_sysctl_header == NULL) {
1031 "br_netfilter: can't register to sysctl.\n");
1032 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1033 dst_entries_destroy(&fake_dst_ops);
1037 printk(KERN_NOTICE "Bridge firewalling registered\n");
1041 void br_netfilter_fini(void)
1043 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1044 #ifdef CONFIG_SYSCTL
1045 unregister_sysctl_table(brnf_sysctl_header);
1047 dst_entries_destroy(&fake_dst_ops);