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;
57 static int brnf_pass_vlan_indev __read_mostly = 0;
59 #define brnf_call_iptables 1
60 #define brnf_call_ip6tables 1
61 #define brnf_call_arptables 1
62 #define brnf_filter_vlan_tagged 0
63 #define brnf_filter_pppoe_tagged 0
64 #define brnf_pass_vlan_indev 0
68 (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IP))
70 #define IS_IPV6(skb) \
71 (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_IPV6))
74 (!vlan_tx_tag_present(skb) && skb->protocol == htons(ETH_P_ARP))
76 static inline __be16 vlan_proto(const struct sk_buff *skb)
78 if (vlan_tx_tag_present(skb))
80 else if (skb->protocol == htons(ETH_P_8021Q))
81 return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
86 #define IS_VLAN_IP(skb) \
87 (vlan_proto(skb) == htons(ETH_P_IP) && \
88 brnf_filter_vlan_tagged)
90 #define IS_VLAN_IPV6(skb) \
91 (vlan_proto(skb) == htons(ETH_P_IPV6) && \
92 brnf_filter_vlan_tagged)
94 #define IS_VLAN_ARP(skb) \
95 (vlan_proto(skb) == htons(ETH_P_ARP) && \
96 brnf_filter_vlan_tagged)
98 static inline __be16 pppoe_proto(const struct sk_buff *skb)
100 return *((__be16 *)(skb_mac_header(skb) + ETH_HLEN +
101 sizeof(struct pppoe_hdr)));
104 #define IS_PPPOE_IP(skb) \
105 (skb->protocol == htons(ETH_P_PPP_SES) && \
106 pppoe_proto(skb) == htons(PPP_IP) && \
107 brnf_filter_pppoe_tagged)
109 #define IS_PPPOE_IPV6(skb) \
110 (skb->protocol == htons(ETH_P_PPP_SES) && \
111 pppoe_proto(skb) == htons(PPP_IPV6) && \
112 brnf_filter_pppoe_tagged)
114 static inline struct rtable *bridge_parent_rtable(const struct net_device *dev)
116 struct net_bridge_port *port;
118 port = br_port_get_rcu(dev);
119 return port ? &port->br->fake_rtable : NULL;
122 static inline struct net_device *bridge_parent(const struct net_device *dev)
124 struct net_bridge_port *port;
126 port = br_port_get_rcu(dev);
127 return port ? port->br->dev : NULL;
130 static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
132 skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
133 if (likely(skb->nf_bridge))
134 atomic_set(&(skb->nf_bridge->use), 1);
136 return skb->nf_bridge;
139 static inline struct nf_bridge_info *nf_bridge_unshare(struct sk_buff *skb)
141 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
143 if (atomic_read(&nf_bridge->use) > 1) {
144 struct nf_bridge_info *tmp = nf_bridge_alloc(skb);
147 memcpy(tmp, nf_bridge, sizeof(struct nf_bridge_info));
148 atomic_set(&tmp->use, 1);
150 nf_bridge_put(nf_bridge);
156 static inline void nf_bridge_push_encap_header(struct sk_buff *skb)
158 unsigned int len = nf_bridge_encap_header_len(skb);
161 skb->network_header -= len;
164 static inline void nf_bridge_pull_encap_header(struct sk_buff *skb)
166 unsigned int len = nf_bridge_encap_header_len(skb);
169 skb->network_header += len;
172 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff *skb)
174 unsigned int len = nf_bridge_encap_header_len(skb);
176 skb_pull_rcsum(skb, len);
177 skb->network_header += len;
180 static inline void nf_bridge_save_header(struct sk_buff *skb)
182 int header_size = ETH_HLEN + nf_bridge_encap_header_len(skb);
184 skb_copy_from_linear_data_offset(skb, -header_size,
185 skb->nf_bridge->data, header_size);
188 /* When handing a packet over to the IP layer
189 * check whether we have a skb that is in the
193 static int br_parse_ip_options(struct sk_buff *skb)
195 struct ip_options *opt;
196 const struct iphdr *iph;
197 struct net_device *dev = skb->dev;
200 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
204 opt = &(IPCB(skb)->opt);
206 /* Basic sanity checks */
207 if (iph->ihl < 5 || iph->version != 4)
210 if (!pskb_may_pull(skb, iph->ihl*4))
214 if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
217 len = ntohs(iph->tot_len);
218 if (skb->len < len) {
219 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INTRUNCATEDPKTS);
221 } else if (len < (iph->ihl*4))
224 if (pskb_trim_rcsum(skb, len)) {
225 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INDISCARDS);
229 memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
233 opt->optlen = iph->ihl*4 - sizeof(struct iphdr);
234 if (ip_options_compile(dev_net(dev), opt, skb))
237 /* Check correct handling of SRR option */
238 if (unlikely(opt->srr)) {
239 struct in_device *in_dev = __in_dev_get_rcu(dev);
240 if (in_dev && !IN_DEV_SOURCE_ROUTE(in_dev))
243 if (ip_options_rcv_srr(skb))
250 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_INHDRERRORS);
255 /* PF_BRIDGE/PRE_ROUTING *********************************************/
256 /* Undo the changes made for ip6tables PREROUTING and continue the
257 * bridge PRE_ROUTING hook. */
258 static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
260 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
263 if (nf_bridge->mask & BRNF_PKT_TYPE) {
264 skb->pkt_type = PACKET_OTHERHOST;
265 nf_bridge->mask ^= BRNF_PKT_TYPE;
267 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
269 rt = bridge_parent_rtable(nf_bridge->physindev);
274 skb_dst_set_noref(skb, &rt->dst);
276 skb->dev = nf_bridge->physindev;
277 nf_bridge_update_protocol(skb);
278 nf_bridge_push_encap_header(skb);
279 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
280 br_handle_frame_finish, 1);
285 /* Obtain the correct destination MAC address, while preserving the original
286 * source MAC address. If we already know this address, we just copy it. If we
287 * don't, we use the neighbour framework to find out. In both cases, we make
288 * sure that br_handle_frame_finish() is called afterwards.
290 static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
292 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
293 struct neighbour *neigh;
294 struct dst_entry *dst;
296 skb->dev = bridge_parent(skb->dev);
300 neigh = dst_neigh_lookup_skb(dst, skb);
304 if (neigh->hh.hh_len) {
305 neigh_hh_bridge(&neigh->hh, skb);
306 skb->dev = nf_bridge->physindev;
307 ret = br_handle_frame_finish(skb);
309 /* the neighbour function below overwrites the complete
310 * MAC header, so we save the Ethernet source address and
313 skb_copy_from_linear_data_offset(skb,
314 -(ETH_HLEN-ETH_ALEN),
315 skb->nf_bridge->data,
317 /* tell br_dev_xmit to continue with forwarding */
318 nf_bridge->mask |= BRNF_BRIDGED_DNAT;
319 /* FIXME Need to refragment */
320 ret = neigh->output(neigh, skb);
322 neigh_release(neigh);
330 /* This requires some explaining. If DNAT has taken place,
331 * we will need to fix up the destination Ethernet address.
333 * There are two cases to consider:
334 * 1. The packet was DNAT'ed to a device in the same bridge
335 * port group as it was received on. We can still bridge
337 * 2. The packet was DNAT'ed to a different device, either
338 * a non-bridged device or another bridge port group.
339 * The packet will need to be routed.
341 * The correct way of distinguishing between these two cases is to
342 * call ip_route_input() and to look at skb->dst->dev, which is
343 * changed to the destination device if ip_route_input() succeeds.
345 * Let's first consider the case that ip_route_input() succeeds:
347 * If the output device equals the logical bridge device the packet
348 * came in on, we can consider this bridging. The corresponding MAC
349 * address will be obtained in br_nf_pre_routing_finish_bridge.
350 * Otherwise, the packet is considered to be routed and we just
351 * change the destination MAC address so that the packet will
352 * later be passed up to the IP stack to be routed. For a redirected
353 * packet, ip_route_input() will give back the localhost as output device,
354 * which differs from the bridge device.
356 * Let's now consider the case that ip_route_input() fails:
358 * This can be because the destination address is martian, in which case
359 * the packet will be dropped.
360 * If IP forwarding is disabled, ip_route_input() will fail, while
361 * ip_route_output_key() can return success. The source
362 * address for ip_route_output_key() is set to zero, so ip_route_output_key()
363 * thinks we're handling a locally generated packet and won't care
364 * if IP forwarding is enabled. If the output device equals the logical bridge
365 * device, we proceed as if ip_route_input() succeeded. If it differs from the
366 * logical bridge port or if ip_route_output_key() fails we drop the packet.
368 static int br_nf_pre_routing_finish(struct sk_buff *skb)
370 struct net_device *dev = skb->dev;
371 struct iphdr *iph = ip_hdr(skb);
372 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
377 frag_max_size = IPCB(skb)->frag_max_size;
378 BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size;
380 if (nf_bridge->mask & BRNF_PKT_TYPE) {
381 skb->pkt_type = PACKET_OTHERHOST;
382 nf_bridge->mask ^= BRNF_PKT_TYPE;
384 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
385 if (dnat_took_place(skb)) {
386 if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
387 struct in_device *in_dev = __in_dev_get_rcu(dev);
389 /* If err equals -EHOSTUNREACH the error is due to a
390 * martian destination or due to the fact that
391 * forwarding is disabled. For most martian packets,
392 * ip_route_output_key() will fail. It won't fail for 2 types of
393 * martian destinations: loopback destinations and destination
394 * 0.0.0.0. In both cases the packet will be dropped because the
395 * destination is the loopback device and not the bridge. */
396 if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
399 rt = ip_route_output(dev_net(dev), iph->daddr, 0,
400 RT_TOS(iph->tos), 0);
402 /* - Bridged-and-DNAT'ed traffic doesn't
403 * require ip_forwarding. */
404 if (rt->dst.dev == dev) {
405 skb_dst_set(skb, &rt->dst);
414 if (skb_dst(skb)->dev == dev) {
416 skb->dev = nf_bridge->physindev;
417 nf_bridge_update_protocol(skb);
418 nf_bridge_push_encap_header(skb);
419 NF_HOOK_THRESH(NFPROTO_BRIDGE,
422 br_nf_pre_routing_finish_bridge,
426 ether_addr_copy(eth_hdr(skb)->h_dest, dev->dev_addr);
427 skb->pkt_type = PACKET_HOST;
430 rt = bridge_parent_rtable(nf_bridge->physindev);
435 skb_dst_set_noref(skb, &rt->dst);
438 skb->dev = nf_bridge->physindev;
439 nf_bridge_update_protocol(skb);
440 nf_bridge_push_encap_header(skb);
441 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
442 br_handle_frame_finish, 1);
447 static struct net_device *brnf_get_logical_dev(struct sk_buff *skb, const struct net_device *dev)
449 struct net_device *vlan, *br;
451 br = bridge_parent(dev);
452 if (brnf_pass_vlan_indev == 0 || !vlan_tx_tag_present(skb))
455 vlan = __vlan_find_dev_deep_rcu(br, skb->vlan_proto,
456 vlan_tx_tag_get(skb) & VLAN_VID_MASK);
458 return vlan ? vlan : br;
461 /* Some common code for IPv4/IPv6 */
462 static struct net_device *setup_pre_routing(struct sk_buff *skb)
464 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
466 if (skb->pkt_type == PACKET_OTHERHOST) {
467 skb->pkt_type = PACKET_HOST;
468 nf_bridge->mask |= BRNF_PKT_TYPE;
471 nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
472 nf_bridge->physindev = skb->dev;
473 skb->dev = brnf_get_logical_dev(skb, skb->dev);
474 if (skb->protocol == htons(ETH_P_8021Q))
475 nf_bridge->mask |= BRNF_8021Q;
476 else if (skb->protocol == htons(ETH_P_PPP_SES))
477 nf_bridge->mask |= BRNF_PPPoE;
479 /* Must drop socket now because of tproxy. */
484 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
485 static int check_hbh_len(struct sk_buff *skb)
487 unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1);
489 const unsigned char *nh = skb_network_header(skb);
491 int len = (raw[1] + 1) << 3;
493 if ((raw + len) - skb->data > skb_headlen(skb))
500 int optlen = nh[off + 1] + 2;
511 if (nh[off + 1] != 4 || (off & 3) != 2)
513 pkt_len = ntohl(*(__be32 *) (nh + off + 2));
514 if (pkt_len <= IPV6_MAXPLEN ||
515 ipv6_hdr(skb)->payload_len)
517 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
519 if (pskb_trim_rcsum(skb,
520 pkt_len + sizeof(struct ipv6hdr)))
522 nh = skb_network_header(skb);
539 /* Replicate the checks that IPv6 does on packet reception and pass the packet
540 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
541 static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops,
543 const struct net_device *in,
544 const struct net_device *out,
545 int (*okfn)(struct sk_buff *))
547 const struct ipv6hdr *hdr;
550 if (skb->len < sizeof(struct ipv6hdr))
553 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
558 if (hdr->version != 6)
561 pkt_len = ntohs(hdr->payload_len);
563 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
564 if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
566 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
569 if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb))
572 nf_bridge_put(skb->nf_bridge);
573 if (!nf_bridge_alloc(skb))
575 if (!setup_pre_routing(skb))
578 skb->protocol = htons(ETH_P_IPV6);
579 NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
580 br_nf_pre_routing_finish_ipv6);
585 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
586 * Replicate the checks that IPv4 does on packet reception.
587 * Set skb->dev to the bridge device (i.e. parent of the
588 * receiving device) to make netfilter happy, the REDIRECT
589 * target in particular. Save the original destination IP
590 * address to be able to detect DNAT afterwards. */
591 static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
593 const struct net_device *in,
594 const struct net_device *out,
595 int (*okfn)(struct sk_buff *))
597 struct net_bridge_port *p;
598 struct net_bridge *br;
599 __u32 len = nf_bridge_encap_header_len(skb);
601 if (unlikely(!pskb_may_pull(skb, len)))
604 p = br_port_get_rcu(in);
609 if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb)) {
610 if (!brnf_call_ip6tables && !br->nf_call_ip6tables)
613 nf_bridge_pull_encap_header_rcsum(skb);
614 return br_nf_pre_routing_ipv6(ops, skb, in, out, okfn);
617 if (!brnf_call_iptables && !br->nf_call_iptables)
620 if (!IS_IP(skb) && !IS_VLAN_IP(skb) && !IS_PPPOE_IP(skb))
623 nf_bridge_pull_encap_header_rcsum(skb);
625 if (br_parse_ip_options(skb))
628 nf_bridge_put(skb->nf_bridge);
629 if (!nf_bridge_alloc(skb))
631 if (!setup_pre_routing(skb))
633 store_orig_dstaddr(skb);
634 skb->protocol = htons(ETH_P_IP);
636 NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, skb->dev, NULL,
637 br_nf_pre_routing_finish);
643 /* PF_BRIDGE/LOCAL_IN ************************************************/
644 /* The packet is locally destined, which requires a real
645 * dst_entry, so detach the fake one. On the way up, the
646 * packet would pass through PRE_ROUTING again (which already
647 * took place when the packet entered the bridge), but we
648 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
649 * prevent this from happening. */
650 static unsigned int br_nf_local_in(const struct nf_hook_ops *ops,
652 const struct net_device *in,
653 const struct net_device *out,
654 int (*okfn)(struct sk_buff *))
656 br_drop_fake_rtable(skb);
660 /* PF_BRIDGE/FORWARD *************************************************/
661 static int br_nf_forward_finish(struct sk_buff *skb)
663 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
664 struct net_device *in;
666 if (!IS_ARP(skb) && !IS_VLAN_ARP(skb)) {
667 in = nf_bridge->physindev;
668 if (nf_bridge->mask & BRNF_PKT_TYPE) {
669 skb->pkt_type = PACKET_OTHERHOST;
670 nf_bridge->mask ^= BRNF_PKT_TYPE;
672 nf_bridge_update_protocol(skb);
674 in = *((struct net_device **)(skb->cb));
676 nf_bridge_push_encap_header(skb);
678 NF_HOOK_THRESH(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, in,
679 skb->dev, br_forward_finish, 1);
684 /* This is the 'purely bridged' case. For IP, we pass the packet to
685 * netfilter with indev and outdev set to the bridge device,
686 * but we are still able to filter on the 'real' indev/outdev
687 * because of the physdev module. For ARP, indev and outdev are the
689 static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
691 const struct net_device *in,
692 const struct net_device *out,
693 int (*okfn)(struct sk_buff *))
695 struct nf_bridge_info *nf_bridge;
696 struct net_device *parent;
702 /* Need exclusive nf_bridge_info since we might have multiple
703 * different physoutdevs. */
704 if (!nf_bridge_unshare(skb))
707 parent = bridge_parent(out);
711 if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
713 else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
718 nf_bridge_pull_encap_header(skb);
720 nf_bridge = skb->nf_bridge;
721 if (skb->pkt_type == PACKET_OTHERHOST) {
722 skb->pkt_type = PACKET_HOST;
723 nf_bridge->mask |= BRNF_PKT_TYPE;
726 if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb))
729 /* The physdev module checks on this */
730 nf_bridge->mask |= BRNF_BRIDGED;
731 nf_bridge->physoutdev = skb->dev;
732 if (pf == NFPROTO_IPV4)
733 skb->protocol = htons(ETH_P_IP);
735 skb->protocol = htons(ETH_P_IPV6);
737 NF_HOOK(pf, NF_INET_FORWARD, skb, brnf_get_logical_dev(skb, in), parent,
738 br_nf_forward_finish);
743 static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops,
745 const struct net_device *in,
746 const struct net_device *out,
747 int (*okfn)(struct sk_buff *))
749 struct net_bridge_port *p;
750 struct net_bridge *br;
751 struct net_device **d = (struct net_device **)(skb->cb);
753 p = br_port_get_rcu(out);
758 if (!brnf_call_arptables && !br->nf_call_arptables)
762 if (!IS_VLAN_ARP(skb))
764 nf_bridge_pull_encap_header(skb);
767 if (arp_hdr(skb)->ar_pln != 4) {
768 if (IS_VLAN_ARP(skb))
769 nf_bridge_push_encap_header(skb);
772 *d = (struct net_device *)in;
773 NF_HOOK(NFPROTO_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in,
774 (struct net_device *)out, br_nf_forward_finish);
779 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4)
780 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
785 /* This is wrong! We should preserve the original fragment
786 * boundaries by preserving frag_list rather than refragmenting.
788 if (skb->protocol == htons(ETH_P_IP) &&
789 skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu &&
791 frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
792 if (br_parse_ip_options(skb))
793 /* Drop invalid packet */
795 IPCB(skb)->frag_max_size = frag_max_size;
796 ret = ip_fragment(skb, br_dev_queue_push_xmit);
798 ret = br_dev_queue_push_xmit(skb);
803 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
805 return br_dev_queue_push_xmit(skb);
809 /* PF_BRIDGE/POST_ROUTING ********************************************/
810 static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops,
812 const struct net_device *in,
813 const struct net_device *out,
814 int (*okfn)(struct sk_buff *))
816 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
817 struct net_device *realoutdev = bridge_parent(skb->dev);
820 if (!nf_bridge || !(nf_bridge->mask & BRNF_BRIDGED))
826 if (IS_IP(skb) || IS_VLAN_IP(skb) || IS_PPPOE_IP(skb))
828 else if (IS_IPV6(skb) || IS_VLAN_IPV6(skb) || IS_PPPOE_IPV6(skb))
833 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
834 * about the value of skb->pkt_type. */
835 if (skb->pkt_type == PACKET_OTHERHOST) {
836 skb->pkt_type = PACKET_HOST;
837 nf_bridge->mask |= BRNF_PKT_TYPE;
840 nf_bridge_pull_encap_header(skb);
841 nf_bridge_save_header(skb);
842 if (pf == NFPROTO_IPV4)
843 skb->protocol = htons(ETH_P_IP);
845 skb->protocol = htons(ETH_P_IPV6);
847 NF_HOOK(pf, NF_INET_POST_ROUTING, skb, NULL, realoutdev,
848 br_nf_dev_queue_xmit);
853 /* IP/SABOTAGE *****************************************************/
854 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
855 * for the second time. */
856 static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops,
858 const struct net_device *in,
859 const struct net_device *out,
860 int (*okfn)(struct sk_buff *))
862 if (skb->nf_bridge &&
863 !(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
870 void br_netfilter_enable(void)
873 EXPORT_SYMBOL_GPL(br_netfilter_enable);
875 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
876 * br_dev_queue_push_xmit is called afterwards */
877 static struct nf_hook_ops br_nf_ops[] __read_mostly = {
879 .hook = br_nf_pre_routing,
880 .owner = THIS_MODULE,
881 .pf = NFPROTO_BRIDGE,
882 .hooknum = NF_BR_PRE_ROUTING,
883 .priority = NF_BR_PRI_BRNF,
886 .hook = br_nf_local_in,
887 .owner = THIS_MODULE,
888 .pf = NFPROTO_BRIDGE,
889 .hooknum = NF_BR_LOCAL_IN,
890 .priority = NF_BR_PRI_BRNF,
893 .hook = br_nf_forward_ip,
894 .owner = THIS_MODULE,
895 .pf = NFPROTO_BRIDGE,
896 .hooknum = NF_BR_FORWARD,
897 .priority = NF_BR_PRI_BRNF - 1,
900 .hook = br_nf_forward_arp,
901 .owner = THIS_MODULE,
902 .pf = NFPROTO_BRIDGE,
903 .hooknum = NF_BR_FORWARD,
904 .priority = NF_BR_PRI_BRNF,
907 .hook = br_nf_post_routing,
908 .owner = THIS_MODULE,
909 .pf = NFPROTO_BRIDGE,
910 .hooknum = NF_BR_POST_ROUTING,
911 .priority = NF_BR_PRI_LAST,
914 .hook = ip_sabotage_in,
915 .owner = THIS_MODULE,
917 .hooknum = NF_INET_PRE_ROUTING,
918 .priority = NF_IP_PRI_FIRST,
921 .hook = ip_sabotage_in,
922 .owner = THIS_MODULE,
924 .hooknum = NF_INET_PRE_ROUTING,
925 .priority = NF_IP6_PRI_FIRST,
931 int brnf_sysctl_call_tables(struct ctl_table *ctl, int write,
932 void __user *buffer, size_t *lenp, loff_t *ppos)
936 ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
938 if (write && *(int *)(ctl->data))
939 *(int *)(ctl->data) = 1;
943 static struct ctl_table brnf_table[] = {
945 .procname = "bridge-nf-call-arptables",
946 .data = &brnf_call_arptables,
947 .maxlen = sizeof(int),
949 .proc_handler = brnf_sysctl_call_tables,
952 .procname = "bridge-nf-call-iptables",
953 .data = &brnf_call_iptables,
954 .maxlen = sizeof(int),
956 .proc_handler = brnf_sysctl_call_tables,
959 .procname = "bridge-nf-call-ip6tables",
960 .data = &brnf_call_ip6tables,
961 .maxlen = sizeof(int),
963 .proc_handler = brnf_sysctl_call_tables,
966 .procname = "bridge-nf-filter-vlan-tagged",
967 .data = &brnf_filter_vlan_tagged,
968 .maxlen = sizeof(int),
970 .proc_handler = brnf_sysctl_call_tables,
973 .procname = "bridge-nf-filter-pppoe-tagged",
974 .data = &brnf_filter_pppoe_tagged,
975 .maxlen = sizeof(int),
977 .proc_handler = brnf_sysctl_call_tables,
980 .procname = "bridge-nf-pass-vlan-input-dev",
981 .data = &brnf_pass_vlan_indev,
982 .maxlen = sizeof(int),
984 .proc_handler = brnf_sysctl_call_tables,
990 static int __init br_netfilter_init(void)
994 ret = nf_register_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
999 brnf_sysctl_header = register_net_sysctl(&init_net, "net/bridge", brnf_table);
1000 if (brnf_sysctl_header == NULL) {
1002 "br_netfilter: can't register to sysctl.\n");
1007 printk(KERN_NOTICE "Bridge firewalling registered\n");
1010 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1014 static void __exit br_netfilter_fini(void)
1016 nf_unregister_hooks(br_nf_ops, ARRAY_SIZE(br_nf_ops));
1017 #ifdef CONFIG_SYSCTL
1018 unregister_net_sysctl_table(brnf_sysctl_header);
1022 module_init(br_netfilter_init);
1023 module_exit(br_netfilter_fini);
1025 MODULE_LICENSE("GPL");
1026 MODULE_AUTHOR("Lennert Buytenhek <buytenh@gnu.org>");
1027 MODULE_AUTHOR("Bart De Schuymer <bdschuym@pandora.be>");
1028 MODULE_DESCRIPTION("Linux ethernet netfilter firewall bridge");