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>
38 #include <net/netfilter/br_netfilter.h>
40 #include <asm/uaccess.h>
41 #include "br_private.h"
43 #include <linux/sysctl.h>
46 #define skb_origaddr(skb) (((struct bridge_skb_cb *) \
47 (skb->nf_bridge->data))->daddr.ipv4)
48 #define store_orig_dstaddr(skb) (skb_origaddr(skb) = ip_hdr(skb)->daddr)
49 #define dnat_took_place(skb) (skb_origaddr(skb) != ip_hdr(skb)->daddr)
52 static struct ctl_table_header *brnf_sysctl_header;
53 static int brnf_call_iptables __read_mostly = 1;
54 static int brnf_call_ip6tables __read_mostly = 1;
55 static int brnf_call_arptables __read_mostly = 1;
56 static int brnf_filter_vlan_tagged __read_mostly = 0;
57 static int brnf_filter_pppoe_tagged __read_mostly = 0;
58 static int brnf_pass_vlan_indev __read_mostly = 0;
60 #define brnf_call_iptables 1
61 #define brnf_call_ip6tables 1
62 #define brnf_call_arptables 1
63 #define brnf_filter_vlan_tagged 0
64 #define brnf_filter_pppoe_tagged 0
65 #define brnf_pass_vlan_indev 0
69 (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IP))
71 #define IS_IPV6(skb) \
72 (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6))
75 (!skb_vlan_tag_present(skb) && skb->protocol == htons(ETH_P_ARP))
77 static inline __be16 vlan_proto(const struct sk_buff *skb)
79 if (skb_vlan_tag_present(skb))
81 else if (skb->protocol == htons(ETH_P_8021Q))
82 return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
87 #define IS_VLAN_IP(skb) \
88 (vlan_proto(skb) == htons(ETH_P_IP) && \
89 brnf_filter_vlan_tagged)
91 #define IS_VLAN_IPV6(skb) \
92 (vlan_proto(skb) == htons(ETH_P_IPV6) && \
93 brnf_filter_vlan_tagged)
95 #define IS_VLAN_ARP(skb) \
96 (vlan_proto(skb) == htons(ETH_P_ARP) && \
97 brnf_filter_vlan_tagged)
99 static inline __be16 pppoe_proto(const struct sk_buff *skb)
101 return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
102 sizeof(struct pppoe_hdr)));
105 #define IS_PPPOE_IP(skb) \
106 (skb->protocol == htons(ETH_P_PPP_SES) && \
107 pppoe_proto(skb) == htons(PPP_IP) && \
108 brnf_filter_pppoe_tagged)
110 #define IS_PPPOE_IPV6(skb) \
111 (skb->protocol == htons(ETH_P_PPP_SES) && \
112 pppoe_proto(skb) == htons(PPP_IPV6) && \
113 brnf_filter_pppoe_tagged)
115 static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
117 struct net_bridge_port *port;
119 port = br_port_get_rcu(dev);
120 return port ? &port->br->fake_rtable : NULL;
123 static inline struct net_device *bridge_parent(const struct net_device *dev)
125 struct net_bridge_port *port;
127 port = br_port_get_rcu(dev);
128 return port ? port->br->dev : NULL;
131 static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
133 skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
134 if (likely(skb->nf_bridge))
135 atomic_set(&(skb->nf_bridge->use), 1);
137 return skb->nf_bridge;
140 static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
142 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
144 if (atomic_read(&nf_bridge->use) > 1) {
145 struct nf_bridge_info *tmp = nf_bridge_alloc(skb);
148 memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info));
149 atomic_set(&tmp->use, 1);
151 nf_bridge_put(nf_bridge);
157 static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
159 unsigned int len = nf_bridge_encap_header_len(skb);
162 skb->network_header -= len;
165 static inline void nf_bridge_pull_encap_header(struct sk_buff *skb)
167 unsigned int len = nf_bridge_encap_header_len(skb);
170 skb->network_header += len;
173 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb)
175 unsigned int len = nf_bridge_encap_header_len(skb);
177 skb_pull_rcsum(skb, len);
178 skb->network_header += len;
181 static inline void nf_bridge_save_header(struct sk_buff *skb)
183 int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
185 skb_copy_from_linear_data_offset(skb, -header_size,
186 skb->nf_bridge->data, header_size);
189 /* When handing a packet over to the IP layer
190 * check whether we have a skb that is in the
194 static int br_parse_ip_options(struct sk_buff *skb)
196 const struct iphdr *iph;
197 struct net_device *dev = skb->dev;
200 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
205 /* Basic sanity checks */
206 if (iph->ihl < 5 || iph->version != 4)
209 if (!pskb_may_pull(skb, iph->ihl*4))
213 if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
216 len = ntohs(iph->tot_len);
217 if (skb->len < len) {
218 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS);
220 } else if (len < (iph->ihl*4))
223 if (pskb_trim_rcsum(skb, len)) {
224 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
228 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
229 /* We should really parse IP options here but until
230 * somebody who actually uses IP options complains to
231 * us we'll just silently ignore the options because
237 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
242 /* PF_BRIDGE/PRE_ROUTING *********************************************/
243 /* Undo the changes made for ip6tables PREROUTING and continue the
244 * bridge PRE_ROUTING hook. */
245 static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
247 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
250 if (nf_bridge->mask & BRNF_PKT_TYPE) {
251 skb->pkt_type = PACKET_OTHERHOST;
252 nf_bridge->mask ^= BRNF_PKT_TYPE;
254 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
256 rt = bridge_parent_rtable(nf_bridge->physindev);
261 skb_dst_set_noref(skb, &rt->dst);
263 skb->dev = nf_bridge->physindev;
264 nf_bridge_update_protocol(skb);
265 nf_bridge_push_encap_header(skb);
266 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
267 br_handle_frame_finish, 1);
272 /* Obtain the correct destination MAC address, while preserving the original
273 * source MAC address. If we already know this address, we just copy it. If we
274 * don't, we use the neighbour framework to find out. In both cases, we make
275 * sure that br_handle_frame_finish() is called afterwards.
277 static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
279 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
280 struct neighbour *neigh;
281 struct dst_entry *dst;
283 skb->dev = bridge_parent(skb->dev);
287 neigh = dst_neigh_lookup_skb(dst, skb);
291 if (neigh->hh.hh_len) {
292 neigh_hh_bridge(&neigh->hh, skb);
293 skb->dev = nf_bridge->physindev;
294 ret = br_handle_frame_finish(skb);
296 /* the neighbour function below overwrites the complete
297 * MAC header, so we save the Ethernet source address and
300 skb_copy_from_linear_data_offset(skb,
301 -(ETH_HLEN-ETH_ALEN),
302 skb->nf_bridge->data,
304 /* tell br_dev_xmit to continue with forwarding */
305 nf_bridge->mask |= BRNF_BRIDGED_DNAT;
306 /* FIXME Need to refragment */
307 ret = neigh->output(neigh, skb);
309 neigh_release(neigh);
317 /* This requires some explaining. If DNAT has taken place,
318 * we will need to fix up the destination Ethernet address.
320 * There are two cases to consider:
321 * 1. The packet was DNAT'ed to a device in the same bridge
322 * port group as it was received on. We can still bridge
324 * 2. The packet was DNAT'ed to a different device, either
325 * a non-bridged device or another bridge port group.
326 * The packet will need to be routed.
328 * The correct way of distinguishing between these two cases is to
329 * call ip_route_input() and to look at skb->dst->dev, which is
330 * changed to the destination device if ip_route_input() succeeds.
332 * Let's first consider the case that ip_route_input() succeeds:
334 * If the output device equals the logical bridge device the packet
335 * came in on, we can consider this bridging. The corresponding MAC
336 * address will be obtained in br_nf_pre_routing_finish_bridge.
337 * Otherwise, the packet is considered to be routed and we just
338 * change the destination MAC address so that the packet will
339 * later be passed up to the IP stack to be routed. For a redirected
340 * packet, ip_route_input() will give back the localhost as output device,
341 * which differs from the bridge device.
343 * Let's now consider the case that ip_route_input() fails:
345 * This can be because the destination address is martian, in which case
346 * the packet will be dropped.
347 * If IP forwarding is disabled, ip_route_input() will fail, while
348 * ip_route_output_key() can return success. The source
349 * address for ip_route_output_key() is set to zero, so ip_route_output_key()
350 * thinks we're handling a locally generated packet and won't care
351 * if IP forwarding is enabled. If the output device equals the logical bridge
352 * device, we proceed as if ip_route_input() succeeded. If it differs from the
353 * logical bridge port or if ip_route_output_key() fails we drop the packet.
355 static int br_nf_pre_routing_finish(struct sk_buff *skb)
357 struct net_device *dev = skb->dev;
358 struct iphdr *iph = ip_hdr(skb);
359 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
364 frag_max_size = IPCB(skb)->frag_max_size;
365 BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size;
367 if (nf_bridge->mask & BRNF_PKT_TYPE) {
368 skb->pkt_type = PACKET_OTHERHOST;
369 nf_bridge->mask ^= BRNF_PKT_TYPE;
371 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
372 if (dnat_took_place(skb)) {
373 if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
374 struct in_device *in_dev = __in_dev_get_rcu(dev);
376 /* If err equals -EHOSTUNREACH the error is due to a
377 * martian destination or due to the fact that
378 * forwarding is disabled. For most martian packets,
379 * ip_route_output_key() will fail. It won't fail for 2 types of
380 * martian destinations: loopback destinations and destination
381 * 0.0.0.0. In both cases the packet will be dropped because the
382 * destination is the loopback device and not the bridge. */
383 if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
386 rt = ip_route_output(dev_net(dev), iph->daddr, 0,
387 RT_TOS(iph->tos), 0);
389 /* - Bridged-and-DNAT'ed traffic doesn't
390 * require ip_forwarding. */
391 if (rt->dst.dev == dev) {
392 skb_dst_set(skb, &rt->dst);
401 if (skb_dst(skb)->dev == dev) {
403 skb->dev = nf_bridge->physindev;
404 nf_bridge_update_protocol(skb);
405 nf_bridge_push_encap_header(skb);
406 NF_HOOK_THRESH(NFPROTO_BRIDGE,
409 br_nf_pre_routing_finish_bridge,
413 ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
414 skb->pkt_type = PACKET_HOST;
417 rt = bridge_parent_rtable(nf_bridge->physindev);
422 skb_dst_set_noref(skb, &rt->dst);
425 skb->dev = nf_bridge->physindev;
426 nf_bridge_update_protocol(skb);
427 nf_bridge_push_encap_header(skb);
428 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
429 br_handle_frame_finish, 1);
434 static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev)
436 struct net_device *vlan, *br;
438 br = bridge_parent(dev);
439 if (brnf_pass_vlan_indev == 0 || !skb_vlan_tag_present(skb))
442 vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto,
443 skb_vlan_tag_get(skb) & VLAN_VID_MASK);
445 return vlan ? vlan : br;
448 /* Some common code for IPv4/IPv6 */
449 static struct net_device *setup_pre_routing(struct sk_buff *skb)
451 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
453 if (skb->pkt_type == PACKET_OTHERHOST) {
454 skb->pkt_type = PACKET_HOST;
455 nf_bridge->mask |= BRNF_PKT_TYPE;
458 nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
459 nf_bridge->physindev = skb->dev;
460 skb->dev = brnf_get_logical_dev(skb, skb->dev);
461 if (skb->protocol == htons(ETH_P_8021Q))
462 nf_bridge->mask |= BRNF_8021Q;
463 else if (skb->protocol == htons(ETH_P_PPP_SES))
464 nf_bridge->mask |= BRNF_PPPoE;
466 /* Must drop socket now because of tproxy. */
471 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
472 static int check_hbh_len(struct sk_buff *skb)
474 unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
476 const unsigned char *nh = skb_network_header(skb);
478 int len = (raw[1] + 1) << 3;
480 if ((raw + len) - skb->data > skb_headlen(skb))
487 int optlen = nh[off + 1] + 2;
498 if (nh[off + 1] != 4 || (off & 3) != 2)
500 pkt_len = ntohl(*(__be32 *) (nh + off + 2));
501 if (pkt_len <= IPV6_MAXPLEN ||
502 ipv6_hdr(skb)->payload_len)
504 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
506 if (pskb_trim_rcsum(skb,
507 pkt_len + sizeof(struct ipv6hdr)))
509 nh = skb_network_header(skb);
526 /* Replicate the checks that IPv6 does on packet reception and pass the packet
527 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
528 static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
530 const struct net_device *in,
531 const struct net_device *out,
532 int (*okfn)(struct sk_buff *))
534 const struct ipv6hdr *hdr;
537 if (skb->len < sizeof(struct ipv6hdr))
540 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
545 if (hdr->version != 6)
548 pkt_len = ntohs(hdr->payload_len);
550 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
551 if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
553 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
556 if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb))
559 nf_bridge_put(skb->nf_bridge);
560 if (!nf_bridge_alloc(skb))
562 if (!setup_pre_routing(skb))
565 skb->protocol = htons(ETH_P_IPV6);
566 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
567 br_nf_pre_routing_finish_ipv6);
572 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
573 * Replicate the checks that IPv4 does on packet reception.
574 * Set skb->dev to the bridge device (i.e. parent of the
575 * receiving device) to make netfilter happy, the REDIRECT
576 * target in particular. Save the original destination IP
577 * address to be able to detect DNAT afterwards. */
578 static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
580 const struct net_device *in,
581 const struct net_device *out,
582 int (*okfn)(struct sk_buff *))
584 struct net_bridge_port *p;
585 struct net_bridge *br;
586 __u32 len = nf_bridge_encap_header_len(skb);
588 if (unlikely(!pskb_may_pull(skb, len)))
591 p = br_port_get_rcu(in);
596 if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) {
597 if (!brnf_call_ip6tables && !br->nf_call_ip6tables)
600 nf_bridge_pull_encap_header_rcsum(skb);
601 return br_nf_pre_routing_ipv6(ops, skb, in, out, okfn);
604 if (!brnf_call_iptables && !br->nf_call_iptables)
607 if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb))
610 nf_bridge_pull_encap_header_rcsum(skb);
612 if (br_parse_ip_options(skb))
615 nf_bridge_put(skb->nf_bridge);
616 if (!nf_bridge_alloc(skb))
618 if (!setup_pre_routing(skb))
620 store_orig_dstaddr(skb);
621 skb->protocol = htons(ETH_P_IP);
623 NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
624 br_nf_pre_routing_finish);
630 /* PF_BRIDGE/LOCAL_IN ************************************************/
631 /* The packet is locally destined, which requires a real
632 * dst_entry, so detach the fake one. On the way up, the
633 * packet would pass through PRE_ROUTING again (which already
634 * took place when the packet entered the bridge), but we
635 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
636 * prevent this from happening. */
637 static unsigned int br_nf_local_in(const struct nf_hook_ops *ops,
639 const struct net_device *in,
640 const struct net_device *out,
641 int (*okfn)(struct sk_buff *))
643 br_drop_fake_rtable(skb);
647 /* PF_BRIDGE/FORWARD *************************************************/
648 static int br_nf_forward_finish(struct sk_buff *skb)
650 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
651 struct net_device *in;
653 if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) {
654 in = nf_bridge->physindev;
655 if (nf_bridge->mask & BRNF_PKT_TYPE) {
656 skb->pkt_type = PACKET_OTHERHOST;
657 nf_bridge->mask ^= BRNF_PKT_TYPE;
659 nf_bridge_update_protocol(skb);
661 in = *((struct net_device **)(skb->cb));
663 nf_bridge_push_encap_header(skb);
665 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in,
666 skb->dev, br_forward_finish, 1);
671 /* This is the 'purely bridged' case. For IP, we pass the packet to
672 * netfilter with indev and outdev set to the bridge device,
673 * but we are still able to filter on the 'real' indev/outdev
674 * because of the physdev module. For ARP, indev and outdev are the
676 static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
678 const struct net_device *in,
679 const struct net_device *out,
680 int (*okfn)(struct sk_buff *))
682 struct nf_bridge_info *nf_bridge;
683 struct net_device *parent;
689 /* Need exclusive nf_bridge_info since we might have multiple
690 * different physoutdevs. */
691 if (!nf_bridge_unshare(skb))
694 parent = bridge_parent(out);
698 if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
700 else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
705 nf_bridge_pull_encap_header(skb);
707 nf_bridge = skb->nf_bridge;
708 if (skb->pkt_type == PACKET_OTHERHOST) {
709 skb->pkt_type = PACKET_HOST;
710 nf_bridge->mask |= BRNF_PKT_TYPE;
713 if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb))
716 /* The physdev module checks on this */
717 nf_bridge->mask |= BRNF_BRIDGED;
718 nf_bridge->physoutdev = skb->dev;
719 if (pf == NFPROTO_IPV4)
720 skb->protocol = htons(ETH_P_IP);
722 skb->protocol = htons(ETH_P_IPV6);
724 NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent,
725 br_nf_forward_finish);
730 static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops,
732 const struct net_device *in,
733 const struct net_device *out,
734 int (*okfn)(struct sk_buff *))
736 struct net_bridge_port *p;
737 struct net_bridge *br;
738 struct net_device **d = (struct net_device **)(skb->cb);
740 p = br_port_get_rcu(out);
745 if (!brnf_call_arptables && !br->nf_call_arptables)
749 if (!IS_VLAN_ARP(skb))
751 nf_bridge_pull_encap_header(skb);
754 if (arp_hdr(skb)->ar_pln != 4) {
755 if (IS_VLAN_ARP(skb))
756 nf_bridge_push_encap_header(skb);
759 *d = (struct net_device *)in;
760 NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in,
761 (struct net_device *)out, br_nf_forward_finish);
766 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
767 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
772 /* This is wrong! We should preserve the original fragment
773 * boundaries by preserving frag_list rather than refragmenting.
775 if (skb->protocol == htons(ETH_P_IP) &&
776 skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu &&
778 frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
779 if (br_parse_ip_options(skb))
780 /* Drop invalid packet */
782 IPCB(skb)->frag_max_size = frag_max_size;
783 ret = ip_fragment(skb, br_dev_queue_push_xmit);
785 ret = br_dev_queue_push_xmit(skb);
790 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
792 return br_dev_queue_push_xmit(skb);
796 /* PF_BRIDGE/POST_ROUTING ********************************************/
797 static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
799 const struct net_device *in,
800 const struct net_device *out,
801 int (*okfn)(struct sk_buff *))
803 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
804 struct net_device *realoutdev = bridge_parent(skb->dev);
807 if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED))
813 if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
815 else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
820 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
821 * about the value of skb->pkt_type. */
822 if (skb->pkt_type == PACKET_OTHERHOST) {
823 skb->pkt_type = PACKET_HOST;
824 nf_bridge->mask |= BRNF_PKT_TYPE;
827 nf_bridge_pull_encap_header(skb);
828 nf_bridge_save_header(skb);
829 if (pf == NFPROTO_IPV4)
830 skb->protocol = htons(ETH_P_IP);
832 skb->protocol = htons(ETH_P_IPV6);
834 NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev,
835 br_nf_dev_queue_xmit);
840 /* IP/SABOTAGE *****************************************************/
841 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
842 * for the second time. */
843 static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops,
845 const struct net_device *in,
846 const struct net_device *out,
847 int (*okfn)(struct sk_buff *))
849 if (skb->nf_bridge &&
850 !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
857 void br_netfilter_enable(void)
860 EXPORT_SYMBOL_GPL(br_netfilter_enable);
862 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
863 * br_dev_queue_push_xmit is called afterwards */
864 static struct nf_hook_ops br_nf_ops[] __read_mostly = {
866 .hook = br_nf_pre_routing,
867 .owner = THIS_MODULE,
868 .pf = NFPROTO_BRIDGE,
869 .hooknum = NF_BR_PRE_ROUTING,
870 .priority = NF_BR_PRI_BRNF,
873 .hook = br_nf_local_in,
874 .owner = THIS_MODULE,
875 .pf = NFPROTO_BRIDGE,
876 .hooknum = NF_BR_LOCAL_IN,
877 .priority = NF_BR_PRI_BRNF,
880 .hook = br_nf_forward_ip,
881 .owner = THIS_MODULE,
882 .pf = NFPROTO_BRIDGE,
883 .hooknum = NF_BR_FORWARD,
884 .priority = NF_BR_PRI_BRNF - 1,
887 .hook = br_nf_forward_arp,
888 .owner = THIS_MODULE,
889 .pf = NFPROTO_BRIDGE,
890 .hooknum = NF_BR_FORWARD,
891 .priority = NF_BR_PRI_BRNF,
894 .hook = br_nf_post_routing,
895 .owner = THIS_MODULE,
896 .pf = NFPROTO_BRIDGE,
897 .hooknum = NF_BR_POST_ROUTING,
898 .priority = NF_BR_PRI_LAST,
901 .hook = ip_sabotage_in,
902 .owner = THIS_MODULE,
904 .hooknum = NF_INET_PRE_ROUTING,
905 .priority = NF_IP_PRI_FIRST,
908 .hook = ip_sabotage_in,
909 .owner = THIS_MODULE,
911 .hooknum = NF_INET_PRE_ROUTING,
912 .priority = NF_IP6_PRI_FIRST,
918 int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
919 void __user *buffer, size_t *lenp, loff_t *ppos)
923 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
925 if (write && *(int *)(ctl->data))
926 *(int *)(ctl->data) = 1;
930 static struct ctl_table brnf_table[] = {
932 .procname = "bridge-nf-call-arptables",
933 .data = &brnf_call_arptables,
934 .maxlen = sizeof(int),
936 .proc_handler = brnf_sysctl_call_tables,
939 .procname = "bridge-nf-call-iptables",
940 .data = &brnf_call_iptables,
941 .maxlen = sizeof(int),
943 .proc_handler = brnf_sysctl_call_tables,
946 .procname = "bridge-nf-call-ip6tables",
947 .data = &brnf_call_ip6tables,
948 .maxlen = sizeof(int),
950 .proc_handler = brnf_sysctl_call_tables,
953 .procname = "bridge-nf-filter-vlan-tagged",
954 .data = &brnf_filter_vlan_tagged,
955 .maxlen = sizeof(int),
957 .proc_handler = brnf_sysctl_call_tables,
960 .procname = "bridge-nf-filter-pppoe-tagged",
961 .data = &brnf_filter_pppoe_tagged,
962 .maxlen = sizeof(int),
964 .proc_handler = brnf_sysctl_call_tables,
967 .procname = "bridge-nf-pass-vlan-input-dev",
968 .data = &brnf_pass_vlan_indev,
969 .maxlen = sizeof(int),
971 .proc_handler = brnf_sysctl_call_tables,
977 static int __init br_netfilter_init(void)
981 ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
986 brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table);
987 if (brnf_sysctl_header == NULL) {
989 "br_netfilter: can't register to sysctl.\n");
990 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
994 printk(KERN_NOTICE "Bridge firewalling registered\n");
998 static void __exit br_netfilter_fini(void)
1000 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1001 #ifdef CONFIG_SYSCTL
1002 unregister_net_sysctl_table(brnf_sysctl_header);
1006 module_init(br_netfilter_init);
1007 module_exit(br_netfilter_fini);
1009 MODULE_LICENSE("GPL");
1010 MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>");
1011 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
1012 MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge");