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 dst_ops fake_dst_ops = {
114 .protocol = cpu_to_be16(ETH_P_IP),
115 .update_pmtu = fake_update_pmtu,
116 .cow_metrics = fake_cow_metrics,
120 * Initialize bogus route table used to keep netfilter happy.
121 * Currently, we fill in the PMTU entry because netfilter
122 * refragmentation needs it, and the rt_flags entry because
123 * ipt_REJECT needs it. Future netfilter modules might
124 * require us to fill additional fields.
126 static const u32 br_dst_default_metrics[RTAX_MAX] = {
127 [RTAX_MTU - 1] = 1500,
130 void br_netfilter_rtable_init(struct net_bridge *br)
132 struct rtable *rt = &br->fake_rtable;
134 atomic_set(&rt->dst.__refcnt, 1);
135 rt->dst.dev = br->dev;
136 rt->dst.path = &rt->dst;
137 dst_init_metrics(&rt->dst, br_dst_default_metrics, true);
138 rt->dst.flags = DST_NOXFRM;
139 rt->dst.ops = &fake_dst_ops;
142 static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
144 struct net_bridge_port *port;
146 port = br_port_get_rcu(dev);
147 return port ? &port->br->fake_rtable : NULL;
150 static inline struct net_device *bridge_parent(const struct net_device *dev)
152 struct net_bridge_port *port;
154 port = br_port_get_rcu(dev);
155 return port ? port->br->dev : NULL;
158 static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
160 skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
161 if (likely(skb->nf_bridge))
162 atomic_set(&(skb->nf_bridge->use), 1);
164 return skb->nf_bridge;
167 static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
169 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
171 if (atomic_read(&nf_bridge->use) > 1) {
172 struct nf_bridge_info *tmp = nf_bridge_alloc(skb);
175 memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info));
176 atomic_set(&tmp->use, 1);
178 nf_bridge_put(nf_bridge);
184 static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
186 unsigned int len = nf_bridge_encap_header_len(skb);
189 skb->network_header -= len;
192 static inline void nf_bridge_pull_encap_header(struct sk_buff *skb)
194 unsigned int len = nf_bridge_encap_header_len(skb);
197 skb->network_header += len;
200 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb)
202 unsigned int len = nf_bridge_encap_header_len(skb);
204 skb_pull_rcsum(skb, len);
205 skb->network_header += len;
208 static inline void nf_bridge_save_header(struct sk_buff *skb)
210 int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
212 skb_copy_from_linear_data_offset(skb, -header_size,
213 skb->nf_bridge->data, header_size);
216 static inline void nf_bridge_update_protocol(struct sk_buff *skb)
218 if (skb->nf_bridge->mask & BRNF_8021Q)
219 skb->protocol = htons(ETH_P_8021Q);
220 else if (skb->nf_bridge->mask & BRNF_PPPoE)
221 skb->protocol = htons(ETH_P_PPP_SES);
224 /* When handing a packet over to the IP layer
225 * check whether we have a skb that is in the
229 static int br_parse_ip_options(struct sk_buff *skb)
231 struct ip_options *opt;
232 const struct iphdr *iph;
233 struct net_device *dev = skb->dev;
237 opt = &(IPCB(skb)->opt);
239 /* Basic sanity checks */
240 if (iph->ihl < 5 || iph->version != 4)
243 if (!pskb_may_pull(skb, iph->ihl*4))
247 if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
250 len = ntohs(iph->tot_len);
251 if (skb->len < len) {
252 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS);
254 } else if (len < (iph->ihl*4))
257 if (pskb_trim_rcsum(skb, len)) {
258 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
262 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
266 opt->optlen = iph->ihl*4 - sizeof(struct iphdr);
267 if (ip_options_compile(dev_net(dev), opt, skb))
270 /* Check correct handling of SRR option */
271 if (unlikely(opt->srr)) {
272 struct in_device *in_dev = __in_dev_get_rcu(dev);
273 if (in_dev && !IN_DEV_SOURCE_ROUTE(in_dev))
276 if (ip_options_rcv_srr(skb))
283 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
288 /* Fill in the header for fragmented IP packets handled by
289 * the IPv4 connection tracking code.
291 int nf_bridge_copy_header(struct sk_buff *skb)
294 unsigned int header_size;
296 nf_bridge_update_protocol(skb);
297 header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
298 err = skb_cow_head(skb, header_size);
302 skb_copy_to_linear_data_offset(skb, -header_size,
303 skb->nf_bridge->data, header_size);
304 __skb_push(skb, nf_bridge_encap_header_len(skb));
308 /* PF_BRIDGE/PRE_ROUTING *********************************************/
309 /* Undo the changes made for ip6tables PREROUTING and continue the
310 * bridge PRE_ROUTING hook. */
311 static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
313 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
316 if (nf_bridge->mask & BRNF_PKT_TYPE) {
317 skb->pkt_type = PACKET_OTHERHOST;
318 nf_bridge->mask ^= BRNF_PKT_TYPE;
320 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
322 rt = bridge_parent_rtable(nf_bridge->physindev);
327 skb_dst_set_noref(skb, &rt->dst);
329 skb->dev = nf_bridge->physindev;
330 nf_bridge_update_protocol(skb);
331 nf_bridge_push_encap_header(skb);
332 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
333 br_handle_frame_finish, 1);
338 /* Obtain the correct destination MAC address, while preserving the original
339 * source MAC address. If we already know this address, we just copy it. If we
340 * don't, we use the neighbour framework to find out. In both cases, we make
341 * sure that br_handle_frame_finish() is called afterwards.
343 static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
345 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
346 struct neighbour *neigh;
347 struct dst_entry *dst;
349 skb->dev = bridge_parent(skb->dev);
353 neigh = dst->neighbour;
354 if (neigh->hh.hh_len) {
355 neigh_hh_bridge(&neigh->hh, skb);
356 skb->dev = nf_bridge->physindev;
357 return br_handle_frame_finish(skb);
358 } else if (dst->neighbour) {
359 /* the neighbour function below overwrites the complete
360 * MAC header, so we save the Ethernet source address and
361 * protocol number. */
362 skb_copy_from_linear_data_offset(skb, -(ETH_HLEN-ETH_ALEN), skb->nf_bridge->data, ETH_HLEN-ETH_ALEN);
363 /* tell br_dev_xmit to continue with forwarding */
364 nf_bridge->mask |= BRNF_BRIDGED_DNAT;
365 return dst->neighbour->output(skb);
372 /* This requires some explaining. If DNAT has taken place,
373 * we will need to fix up the destination Ethernet address.
375 * There are two cases to consider:
376 * 1. The packet was DNAT'ed to a device in the same bridge
377 * port group as it was received on. We can still bridge
379 * 2. The packet was DNAT'ed to a different device, either
380 * a non-bridged device or another bridge port group.
381 * The packet will need to be routed.
383 * The correct way of distinguishing between these two cases is to
384 * call ip_route_input() and to look at skb->dst->dev, which is
385 * changed to the destination device if ip_route_input() succeeds.
387 * Let's first consider the case that ip_route_input() succeeds:
389 * If the output device equals the logical bridge device the packet
390 * came in on, we can consider this bridging. The corresponding MAC
391 * address will be obtained in br_nf_pre_routing_finish_bridge.
392 * Otherwise, the packet is considered to be routed and we just
393 * change the destination MAC address so that the packet will
394 * later be passed up to the IP stack to be routed. For a redirected
395 * packet, ip_route_input() will give back the localhost as output device,
396 * which differs from the bridge device.
398 * Let's now consider the case that ip_route_input() fails:
400 * This can be because the destination address is martian, in which case
401 * the packet will be dropped.
402 * If IP forwarding is disabled, ip_route_input() will fail, while
403 * ip_route_output_key() can return success. The source
404 * address for ip_route_output_key() is set to zero, so ip_route_output_key()
405 * thinks we're handling a locally generated packet and won't care
406 * if IP forwarding is enabled. If the output device equals the logical bridge
407 * device, we proceed as if ip_route_input() succeeded. If it differs from the
408 * logical bridge port or if ip_route_output_key() fails we drop the packet.
410 static int br_nf_pre_routing_finish(struct sk_buff *skb)
412 struct net_device *dev = skb->dev;
413 struct iphdr *iph = ip_hdr(skb);
414 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
418 if (nf_bridge->mask & BRNF_PKT_TYPE) {
419 skb->pkt_type = PACKET_OTHERHOST;
420 nf_bridge->mask ^= BRNF_PKT_TYPE;
422 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
423 if (dnat_took_place(skb)) {
424 if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
425 struct in_device *in_dev = __in_dev_get_rcu(dev);
427 /* If err equals -EHOSTUNREACH the error is due to a
428 * martian destination or due to the fact that
429 * forwarding is disabled. For most martian packets,
430 * ip_route_output_key() will fail. It won't fail for 2 types of
431 * martian destinations: loopback destinations and destination
432 * 0.0.0.0. In both cases the packet will be dropped because the
433 * destination is the loopback device and not the bridge. */
434 if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
437 rt = ip_route_output(dev_net(dev), iph->daddr, 0,
438 RT_TOS(iph->tos), 0);
440 /* - Bridged-and-DNAT'ed traffic doesn't
441 * require ip_forwarding. */
442 if (rt->dst.dev == dev) {
443 skb_dst_set(skb, &rt->dst);
452 if (skb_dst(skb)->dev == dev) {
454 skb->dev = nf_bridge->physindev;
455 nf_bridge_update_protocol(skb);
456 nf_bridge_push_encap_header(skb);
457 NF_HOOK_THRESH(NFPROTO_BRIDGE,
460 br_nf_pre_routing_finish_bridge,
464 memcpy(eth_hdr(skb)->h_dest, dev->dev_addr, ETH_ALEN);
465 skb->pkt_type = PACKET_HOST;
468 rt = bridge_parent_rtable(nf_bridge->physindev);
473 skb_dst_set_noref(skb, &rt->dst);
476 skb->dev = nf_bridge->physindev;
477 nf_bridge_update_protocol(skb);
478 nf_bridge_push_encap_header(skb);
479 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
480 br_handle_frame_finish, 1);
485 /* Some common code for IPv4/IPv6 */
486 static struct net_device *setup_pre_routing(struct sk_buff *skb)
488 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
490 if (skb->pkt_type == PACKET_OTHERHOST) {
491 skb->pkt_type = PACKET_HOST;
492 nf_bridge->mask |= BRNF_PKT_TYPE;
495 nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
496 nf_bridge->physindev = skb->dev;
497 skb->dev = bridge_parent(skb->dev);
498 if (skb->protocol == htons(ETH_P_8021Q))
499 nf_bridge->mask |= BRNF_8021Q;
500 else if (skb->protocol == htons(ETH_P_PPP_SES))
501 nf_bridge->mask |= BRNF_PPPoE;
506 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
507 static int check_hbh_len(struct sk_buff *skb)
509 unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
511 const unsigned char *nh = skb_network_header(skb);
513 int len = (raw[1] + 1) << 3;
515 if ((raw + len) - skb->data > skb_headlen(skb))
522 int optlen = nh[off + 1] + 2;
533 if (nh[off + 1] != 4 || (off & 3) != 2)
535 pkt_len = ntohl(*(__be32 *) (nh + off + 2));
536 if (pkt_len <= IPV6_MAXPLEN ||
537 ipv6_hdr(skb)->payload_len)
539 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
541 if (pskb_trim_rcsum(skb,
542 pkt_len + sizeof(struct ipv6hdr)))
544 nh = skb_network_header(skb);
561 /* Replicate the checks that IPv6 does on packet reception and pass the packet
562 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
563 static unsigned int br_nf_pre_routing_ipv6(unsigned int hook,
565 const struct net_device *in,
566 const struct net_device *out,
567 int (*okfn)(struct sk_buff *))
569 const struct ipv6hdr *hdr;
572 if (skb->len < sizeof(struct ipv6hdr))
575 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
580 if (hdr->version != 6)
583 pkt_len = ntohs(hdr->payload_len);
585 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
586 if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
588 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
591 if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb))
594 nf_bridge_put(skb->nf_bridge);
595 if (!nf_bridge_alloc(skb))
597 if (!setup_pre_routing(skb))
600 skb->protocol = htons(ETH_P_IPV6);
601 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
602 br_nf_pre_routing_finish_ipv6);
607 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
608 * Replicate the checks that IPv4 does on packet reception.
609 * Set skb->dev to the bridge device (i.e. parent of the
610 * receiving device) to make netfilter happy, the REDIRECT
611 * target in particular. Save the original destination IP
612 * address to be able to detect DNAT afterwards. */
613 static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff *skb,
614 const struct net_device *in,
615 const struct net_device *out,
616 int (*okfn)(struct sk_buff *))
618 struct net_bridge_port *p;
619 struct net_bridge *br;
620 __u32 len = nf_bridge_encap_header_len(skb);
622 if (unlikely(!pskb_may_pull(skb, len)))
625 p = br_port_get_rcu(in);
630 if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) ||
631 IS_PPPOE_IPV6(skb)) {
632 if (!brnf_call_ip6tables && !br->nf_call_ip6tables)
635 nf_bridge_pull_encap_header_rcsum(skb);
636 return br_nf_pre_routing_ipv6(hook, skb, in, out, okfn);
639 if (!brnf_call_iptables && !br->nf_call_iptables)
642 if (skb->protocol != htons(ETH_P_IP) && !IS_VLAN_IP(skb) &&
646 nf_bridge_pull_encap_header_rcsum(skb);
648 if (br_parse_ip_options(skb))
651 nf_bridge_put(skb->nf_bridge);
652 if (!nf_bridge_alloc(skb))
654 if (!setup_pre_routing(skb))
656 store_orig_dstaddr(skb);
657 skb->protocol = htons(ETH_P_IP);
659 NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
660 br_nf_pre_routing_finish);
666 /* PF_BRIDGE/LOCAL_IN ************************************************/
667 /* The packet is locally destined, which requires a real
668 * dst_entry, so detach the fake one. On the way up, the
669 * packet would pass through PRE_ROUTING again (which already
670 * took place when the packet entered the bridge), but we
671 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
672 * prevent this from happening. */
673 static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff *skb,
674 const struct net_device *in,
675 const struct net_device *out,
676 int (*okfn)(struct sk_buff *))
678 struct rtable *rt = skb_rtable(skb);
680 if (rt && rt == bridge_parent_rtable(in))
686 /* PF_BRIDGE/FORWARD *************************************************/
687 static int br_nf_forward_finish(struct sk_buff *skb)
689 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
690 struct net_device *in;
692 if (skb->protocol != htons(ETH_P_ARP) && !IS_VLAN_ARP(skb)) {
693 in = nf_bridge->physindev;
694 if (nf_bridge->mask & BRNF_PKT_TYPE) {
695 skb->pkt_type = PACKET_OTHERHOST;
696 nf_bridge->mask ^= BRNF_PKT_TYPE;
698 nf_bridge_update_protocol(skb);
700 in = *((struct net_device **)(skb->cb));
702 nf_bridge_push_encap_header(skb);
704 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in,
705 skb->dev, br_forward_finish, 1);
709 /* This is the 'purely bridged' case. For IP, we pass the packet to
710 * netfilter with indev and outdev set to the bridge device,
711 * but we are still able to filter on the 'real' indev/outdev
712 * because of the physdev module. For ARP, indev and outdev are the
714 static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff *skb,
715 const struct net_device *in,
716 const struct net_device *out,
717 int (*okfn)(struct sk_buff *))
719 struct nf_bridge_info *nf_bridge;
720 struct net_device *parent;
726 /* Need exclusive nf_bridge_info since we might have multiple
727 * different physoutdevs. */
728 if (!nf_bridge_unshare(skb))
731 parent = bridge_parent(out);
735 if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) ||
738 else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) ||
744 nf_bridge_pull_encap_header(skb);
746 nf_bridge = skb->nf_bridge;
747 if (skb->pkt_type == PACKET_OTHERHOST) {
748 skb->pkt_type = PACKET_HOST;
749 nf_bridge->mask |= BRNF_PKT_TYPE;
752 if (pf == PF_INET && br_parse_ip_options(skb))
755 /* The physdev module checks on this */
756 nf_bridge->mask |= BRNF_BRIDGED;
757 nf_bridge->physoutdev = skb->dev;
759 skb->protocol = htons(ETH_P_IP);
761 skb->protocol = htons(ETH_P_IPV6);
763 NF_HOOK(pf, NF_INET_FORWARD, skb, bridge_parent(in), parent,
764 br_nf_forward_finish);
769 static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff *skb,
770 const struct net_device *in,
771 const struct net_device *out,
772 int (*okfn)(struct sk_buff *))
774 struct net_bridge_port *p;
775 struct net_bridge *br;
776 struct net_device **d = (struct net_device **)(skb->cb);
778 p = br_port_get_rcu(out);
783 if (!brnf_call_arptables && !br->nf_call_arptables)
786 if (skb->protocol != htons(ETH_P_ARP)) {
787 if (!IS_VLAN_ARP(skb))
789 nf_bridge_pull_encap_header(skb);
792 if (arp_hdr(skb)->ar_pln != 4) {
793 if (IS_VLAN_ARP(skb))
794 nf_bridge_push_encap_header(skb);
797 *d = (struct net_device *)in;
798 NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in,
799 (struct net_device *)out, br_nf_forward_finish);
804 #if defined(CONFIG_NF_CONNTRACK_IPV4) || defined(CONFIG_NF_CONNTRACK_IPV4_MODULE)
805 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
809 if (skb->nfct != NULL && skb->protocol == htons(ETH_P_IP) &&
810 skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu &&
812 if (br_parse_ip_options(skb))
813 /* Drop invalid packet */
815 ret = ip_fragment(skb, br_dev_queue_push_xmit);
817 ret = br_dev_queue_push_xmit(skb);
822 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
824 return br_dev_queue_push_xmit(skb);
828 /* PF_BRIDGE/POST_ROUTING ********************************************/
829 static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff *skb,
830 const struct net_device *in,
831 const struct net_device *out,
832 int (*okfn)(struct sk_buff *))
834 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
835 struct net_device *realoutdev = bridge_parent(skb->dev);
838 if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED))
844 if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb) ||
847 else if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb) ||
853 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
854 * about the value of skb->pkt_type. */
855 if (skb->pkt_type == PACKET_OTHERHOST) {
856 skb->pkt_type = PACKET_HOST;
857 nf_bridge->mask |= BRNF_PKT_TYPE;
860 nf_bridge_pull_encap_header(skb);
861 nf_bridge_save_header(skb);
863 skb->protocol = htons(ETH_P_IP);
865 skb->protocol = htons(ETH_P_IPV6);
867 NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev,
868 br_nf_dev_queue_xmit);
873 /* IP/SABOTAGE *****************************************************/
874 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
875 * for the second time. */
876 static unsigned int ip_sabotage_in(unsigned int hook, struct sk_buff *skb,
877 const struct net_device *in,
878 const struct net_device *out,
879 int (*okfn)(struct sk_buff *))
881 if (skb->nf_bridge &&
882 !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
889 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
890 * br_dev_queue_push_xmit is called afterwards */
891 static struct nf_hook_ops br_nf_ops[] __read_mostly = {
893 .hook = br_nf_pre_routing,
894 .owner = THIS_MODULE,
896 .hooknum = NF_BR_PRE_ROUTING,
897 .priority = NF_BR_PRI_BRNF,
900 .hook = br_nf_local_in,
901 .owner = THIS_MODULE,
903 .hooknum = NF_BR_LOCAL_IN,
904 .priority = NF_BR_PRI_BRNF,
907 .hook = br_nf_forward_ip,
908 .owner = THIS_MODULE,
910 .hooknum = NF_BR_FORWARD,
911 .priority = NF_BR_PRI_BRNF - 1,
914 .hook = br_nf_forward_arp,
915 .owner = THIS_MODULE,
917 .hooknum = NF_BR_FORWARD,
918 .priority = NF_BR_PRI_BRNF,
921 .hook = br_nf_post_routing,
922 .owner = THIS_MODULE,
924 .hooknum = NF_BR_POST_ROUTING,
925 .priority = NF_BR_PRI_LAST,
928 .hook = ip_sabotage_in,
929 .owner = THIS_MODULE,
931 .hooknum = NF_INET_PRE_ROUTING,
932 .priority = NF_IP_PRI_FIRST,
935 .hook = ip_sabotage_in,
936 .owner = THIS_MODULE,
938 .hooknum = NF_INET_PRE_ROUTING,
939 .priority = NF_IP6_PRI_FIRST,
945 int brnf_sysctl_call_tables(ctl_table * ctl, int write,
946 void __user * buffer, size_t * lenp, loff_t * ppos)
950 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
952 if (write && *(int *)(ctl->data))
953 *(int *)(ctl->data) = 1;
957 static ctl_table brnf_table[] = {
959 .procname = "bridge-nf-call-arptables",
960 .data = &brnf_call_arptables,
961 .maxlen = sizeof(int),
963 .proc_handler = brnf_sysctl_call_tables,
966 .procname = "bridge-nf-call-iptables",
967 .data = &brnf_call_iptables,
968 .maxlen = sizeof(int),
970 .proc_handler = brnf_sysctl_call_tables,
973 .procname = "bridge-nf-call-ip6tables",
974 .data = &brnf_call_ip6tables,
975 .maxlen = sizeof(int),
977 .proc_handler = brnf_sysctl_call_tables,
980 .procname = "bridge-nf-filter-vlan-tagged",
981 .data = &brnf_filter_vlan_tagged,
982 .maxlen = sizeof(int),
984 .proc_handler = brnf_sysctl_call_tables,
987 .procname = "bridge-nf-filter-pppoe-tagged",
988 .data = &brnf_filter_pppoe_tagged,
989 .maxlen = sizeof(int),
991 .proc_handler = brnf_sysctl_call_tables,
996 static struct ctl_path brnf_path[] = {
997 { .procname = "net", },
998 { .procname = "bridge", },
1003 int __init br_netfilter_init(void)
1007 ret = dst_entries_init(&fake_dst_ops);
1011 ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1013 dst_entries_destroy(&fake_dst_ops);
1016 #ifdef CONFIG_SYSCTL
1017 brnf_sysctl_header = register_sysctl_paths(brnf_path, brnf_table);
1018 if (brnf_sysctl_header == NULL) {
1020 "br_netfilter: can't register to sysctl.\n");
1021 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1022 dst_entries_destroy(&fake_dst_ops);
1026 printk(KERN_NOTICE "Bridge firewalling registered\n");
1030 void br_netfilter_fini(void)
1032 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1033 #ifdef CONFIG_SYSCTL
1034 unregister_sysctl_table(brnf_sysctl_header);
1036 dst_entries_destroy(&fake_dst_ops);