[CONNECTOR]: Replace delayed work with usual work queue.
[linux-2.6/verdex.git] / net / bridge / br_netfilter.c
blobea3337ad0edcf3b7b19132fc5770ce5e4c90eeb4
1 /*
2 * Handle firewalling
3 * Linux ethernet bridge
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 * Bart De Schuymer (maintainer) <bdschuym@pandora.be>
9 * Changes:
10 * Apr 29 2003: physdev module support (bdschuym)
11 * Jun 19 2003: let arptables see bridged ARP traffic (bdschuym)
12 * Oct 06 2003: filter encapsulated IP/ARP VLAN traffic on untagged bridge
13 * (bdschuym)
14 * Sep 01 2004: add IPv6 filtering (bdschuym)
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License
18 * as published by the Free Software Foundation; either version
19 * 2 of the License, or (at your option) any later version.
21 * Lennert dedicates this file to Kerstin Wurdinger.
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/ip.h>
27 #include <linux/netdevice.h>
28 #include <linux/skbuff.h>
29 #include <linux/if_arp.h>
30 #include <linux/if_ether.h>
31 #include <linux/if_vlan.h>
32 #include <linux/netfilter_bridge.h>
33 #include <linux/netfilter_ipv4.h>
34 #include <linux/netfilter_ipv6.h>
35 #include <linux/netfilter_arp.h>
36 #include <linux/in_route.h>
37 #include <linux/inetdevice.h>
39 #include <net/ip.h>
40 #include <net/ipv6.h>
41 #include <net/route.h>
43 #include <asm/uaccess.h>
44 #include "br_private.h"
45 #ifdef CONFIG_SYSCTL
46 #include <linux/sysctl.h>
47 #endif
49 #define skb_origaddr(skb) (((struct bridge_skb_cb *) \
50 (skb->nf_bridge->data))->daddr.ipv4)
51 #define store_orig_dstaddr(skb) (skb_origaddr(skb) = (skb)->nh.iph->daddr)
52 #define dnat_took_place(skb) (skb_origaddr(skb) != (skb)->nh.iph->daddr)
54 #ifdef CONFIG_SYSCTL
55 static struct ctl_table_header *brnf_sysctl_header;
56 static int brnf_call_iptables __read_mostly = 1;
57 static int brnf_call_ip6tables __read_mostly = 1;
58 static int brnf_call_arptables __read_mostly = 1;
59 static int brnf_filter_vlan_tagged __read_mostly = 1;
60 #else
61 #define brnf_filter_vlan_tagged 1
62 #endif
64 static __be16 inline vlan_proto(const struct sk_buff *skb)
66 return vlan_eth_hdr(skb)->h_vlan_encapsulated_proto;
69 #define IS_VLAN_IP(skb) \
70 (skb->protocol == htons(ETH_P_8021Q) && \
71 vlan_proto(skb) == htons(ETH_P_IP) && \
72 brnf_filter_vlan_tagged)
74 #define IS_VLAN_IPV6(skb) \
75 (skb->protocol == htons(ETH_P_8021Q) && \
76 vlan_proto(skb) == htons(ETH_P_IPV6) &&\
77 brnf_filter_vlan_tagged)
79 #define IS_VLAN_ARP(skb) \
80 (skb->protocol == htons(ETH_P_8021Q) && \
81 vlan_proto(skb) == htons(ETH_P_ARP) && \
82 brnf_filter_vlan_tagged)
84 /* We need these fake structures to make netfilter happy --
85 * lots of places assume that skb->dst != NULL, which isn't
86 * all that unreasonable.
88 * Currently, we fill in the PMTU entry because netfilter
89 * refragmentation needs it, and the rt_flags entry because
90 * ipt_REJECT needs it. Future netfilter modules might
91 * require us to fill additional fields. */
92 static struct net_device __fake_net_device = {
93 .hard_header_len = ETH_HLEN
96 static struct rtable __fake_rtable = {
97 .u = {
98 .dst = {
99 .__refcnt = ATOMIC_INIT(1),
100 .dev = &__fake_net_device,
101 .path = &__fake_rtable.u.dst,
102 .metrics = {[RTAX_MTU - 1] = 1500},
103 .flags = DST_NOXFRM,
106 .rt_flags = 0,
109 static inline struct net_device *bridge_parent(const struct net_device *dev)
111 struct net_bridge_port *port = rcu_dereference(dev->br_port);
113 return port ? port->br->dev : NULL;
116 static inline struct nf_bridge_info *nf_bridge_alloc(struct sk_buff *skb)
118 skb->nf_bridge = kzalloc(sizeof(struct nf_bridge_info), GFP_ATOMIC);
119 if (likely(skb->nf_bridge))
120 atomic_set(&(skb->nf_bridge->use), 1);
122 return skb->nf_bridge;
125 static inline void nf_bridge_save_header(struct sk_buff *skb)
127 int header_size = ETH_HLEN;
129 if (skb->protocol == htons(ETH_P_8021Q))
130 header_size += VLAN_HLEN;
132 memcpy(skb->nf_bridge->data, skb->data - header_size, header_size);
136 * When forwarding bridge frames, we save a copy of the original
137 * header before processing.
139 int nf_bridge_copy_header(struct sk_buff *skb)
141 int err;
142 int header_size = ETH_HLEN;
144 if (skb->protocol == htons(ETH_P_8021Q))
145 header_size += VLAN_HLEN;
147 err = skb_cow(skb, header_size);
148 if (err)
149 return err;
151 memcpy(skb->data - header_size, skb->nf_bridge->data, header_size);
153 if (skb->protocol == htons(ETH_P_8021Q))
154 __skb_push(skb, VLAN_HLEN);
155 return 0;
158 /* PF_BRIDGE/PRE_ROUTING *********************************************/
159 /* Undo the changes made for ip6tables PREROUTING and continue the
160 * bridge PRE_ROUTING hook. */
161 static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb)
163 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
165 if (nf_bridge->mask & BRNF_PKT_TYPE) {
166 skb->pkt_type = PACKET_OTHERHOST;
167 nf_bridge->mask ^= BRNF_PKT_TYPE;
169 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
171 skb->dst = (struct dst_entry *)&__fake_rtable;
172 dst_hold(skb->dst);
174 skb->dev = nf_bridge->physindev;
175 if (skb->protocol == htons(ETH_P_8021Q)) {
176 skb_push(skb, VLAN_HLEN);
177 skb->nh.raw -= VLAN_HLEN;
179 NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
180 br_handle_frame_finish, 1);
182 return 0;
185 static void __br_dnat_complain(void)
187 static unsigned long last_complaint;
189 if (jiffies - last_complaint >= 5 * HZ) {
190 printk(KERN_WARNING "Performing cross-bridge DNAT requires IP "
191 "forwarding to be enabled\n");
192 last_complaint = jiffies;
196 /* This requires some explaining. If DNAT has taken place,
197 * we will need to fix up the destination Ethernet address,
198 * and this is a tricky process.
200 * There are two cases to consider:
201 * 1. The packet was DNAT'ed to a device in the same bridge
202 * port group as it was received on. We can still bridge
203 * the packet.
204 * 2. The packet was DNAT'ed to a different device, either
205 * a non-bridged device or another bridge port group.
206 * The packet will need to be routed.
208 * The correct way of distinguishing between these two cases is to
209 * call ip_route_input() and to look at skb->dst->dev, which is
210 * changed to the destination device if ip_route_input() succeeds.
212 * Let us first consider the case that ip_route_input() succeeds:
214 * If skb->dst->dev equals the logical bridge device the packet
215 * came in on, we can consider this bridging. We then call
216 * skb->dst->output() which will make the packet enter br_nf_local_out()
217 * not much later. In that function it is assured that the iptables
218 * FORWARD chain is traversed for the packet.
220 * Otherwise, the packet is considered to be routed and we just
221 * change the destination MAC address so that the packet will
222 * later be passed up to the IP stack to be routed. For a redirected
223 * packet, ip_route_input() will give back the localhost as output device,
224 * which differs from the bridge device.
226 * Let us now consider the case that ip_route_input() fails:
228 * This can be because the destination address is martian, in which case
229 * the packet will be dropped.
230 * After a "echo '0' > /proc/sys/net/ipv4/ip_forward" ip_route_input()
231 * will fail, while __ip_route_output_key() will return success. The source
232 * address for __ip_route_output_key() is set to zero, so __ip_route_output_key
233 * thinks we're handling a locally generated packet and won't care
234 * if IP forwarding is allowed. We send a warning message to the users's
235 * log telling her to put IP forwarding on.
237 * ip_route_input() will also fail if there is no route available.
238 * In that case we just drop the packet.
240 * --Lennert, 20020411
241 * --Bart, 20020416 (updated)
242 * --Bart, 20021007 (updated)
243 * --Bart, 20062711 (updated) */
244 static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb)
246 if (skb->pkt_type == PACKET_OTHERHOST) {
247 skb->pkt_type = PACKET_HOST;
248 skb->nf_bridge->mask |= BRNF_PKT_TYPE;
250 skb->nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
252 skb->dev = bridge_parent(skb->dev);
253 if (!skb->dev)
254 kfree_skb(skb);
255 else {
256 if (skb->protocol == htons(ETH_P_8021Q)) {
257 skb_pull(skb, VLAN_HLEN);
258 skb->nh.raw += VLAN_HLEN;
260 skb->dst->output(skb);
262 return 0;
265 static int br_nf_pre_routing_finish(struct sk_buff *skb)
267 struct net_device *dev = skb->dev;
268 struct iphdr *iph = skb->nh.iph;
269 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
270 int err;
272 if (nf_bridge->mask & BRNF_PKT_TYPE) {
273 skb->pkt_type = PACKET_OTHERHOST;
274 nf_bridge->mask ^= BRNF_PKT_TYPE;
276 nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
277 if (dnat_took_place(skb)) {
278 if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
279 struct rtable *rt;
280 struct flowi fl = {
281 .nl_u = {
282 .ip4_u = {
283 .daddr = iph->daddr,
284 .saddr = 0,
285 .tos = RT_TOS(iph->tos) },
287 .proto = 0,
289 struct in_device *in_dev = in_dev_get(dev);
291 /* If err equals -EHOSTUNREACH the error is due to a
292 * martian destination or due to the fact that
293 * forwarding is disabled. For most martian packets,
294 * ip_route_output_key() will fail. It won't fail for 2 types of
295 * martian destinations: loopback destinations and destination
296 * 0.0.0.0. In both cases the packet will be dropped because the
297 * destination is the loopback device and not the bridge. */
298 if (err != -EHOSTUNREACH || !in_dev || IN_DEV_FORWARD(in_dev))
299 goto free_skb;
301 if (!ip_route_output_key(&rt, &fl)) {
302 /* - Bridged-and-DNAT'ed traffic doesn't
303 * require ip_forwarding. */
304 if (((struct dst_entry *)rt)->dev == dev) {
305 skb->dst = (struct dst_entry *)rt;
306 goto bridged_dnat;
308 /* we are sure that forwarding is disabled, so printing
309 * this message is no problem. Note that the packet could
310 * still have a martian destination address, in which case
311 * the packet could be dropped even if forwarding were enabled */
312 __br_dnat_complain();
313 dst_release((struct dst_entry *)rt);
315 free_skb:
316 kfree_skb(skb);
317 return 0;
318 } else {
319 if (skb->dst->dev == dev) {
320 bridged_dnat:
321 /* Tell br_nf_local_out this is a
322 * bridged frame */
323 nf_bridge->mask |= BRNF_BRIDGED_DNAT;
324 skb->dev = nf_bridge->physindev;
325 if (skb->protocol ==
326 htons(ETH_P_8021Q)) {
327 skb_push(skb, VLAN_HLEN);
328 skb->nh.raw -= VLAN_HLEN;
330 NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING,
331 skb, skb->dev, NULL,
332 br_nf_pre_routing_finish_bridge,
334 return 0;
336 memcpy(eth_hdr(skb)->h_dest, dev->dev_addr, ETH_ALEN);
337 skb->pkt_type = PACKET_HOST;
339 } else {
340 skb->dst = (struct dst_entry *)&__fake_rtable;
341 dst_hold(skb->dst);
344 skb->dev = nf_bridge->physindev;
345 if (skb->protocol == htons(ETH_P_8021Q)) {
346 skb_push(skb, VLAN_HLEN);
347 skb->nh.raw -= VLAN_HLEN;
349 NF_HOOK_THRESH(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
350 br_handle_frame_finish, 1);
352 return 0;
355 /* Some common code for IPv4/IPv6 */
356 static struct net_device *setup_pre_routing(struct sk_buff *skb)
358 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
360 if (skb->pkt_type == PACKET_OTHERHOST) {
361 skb->pkt_type = PACKET_HOST;
362 nf_bridge->mask |= BRNF_PKT_TYPE;
365 nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
366 nf_bridge->physindev = skb->dev;
367 skb->dev = bridge_parent(skb->dev);
369 return skb->dev;
372 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
373 static int check_hbh_len(struct sk_buff *skb)
375 unsigned char *raw = (u8 *) (skb->nh.ipv6h + 1);
376 u32 pkt_len;
377 int off = raw - skb->nh.raw;
378 int len = (raw[1] + 1) << 3;
380 if ((raw + len) - skb->data > skb_headlen(skb))
381 goto bad;
383 off += 2;
384 len -= 2;
386 while (len > 0) {
387 int optlen = skb->nh.raw[off + 1] + 2;
389 switch (skb->nh.raw[off]) {
390 case IPV6_TLV_PAD0:
391 optlen = 1;
392 break;
394 case IPV6_TLV_PADN:
395 break;
397 case IPV6_TLV_JUMBO:
398 if (skb->nh.raw[off + 1] != 4 || (off & 3) != 2)
399 goto bad;
400 pkt_len = ntohl(*(__be32 *) (skb->nh.raw + off + 2));
401 if (pkt_len <= IPV6_MAXPLEN ||
402 skb->nh.ipv6h->payload_len)
403 goto bad;
404 if (pkt_len > skb->len - sizeof(struct ipv6hdr))
405 goto bad;
406 if (pskb_trim_rcsum(skb,
407 pkt_len + sizeof(struct ipv6hdr)))
408 goto bad;
409 break;
410 default:
411 if (optlen > len)
412 goto bad;
413 break;
415 off += optlen;
416 len -= optlen;
418 if (len == 0)
419 return 0;
420 bad:
421 return -1;
425 /* Replicate the checks that IPv6 does on packet reception and pass the packet
426 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
427 static unsigned int br_nf_pre_routing_ipv6(unsigned int hook,
428 struct sk_buff *skb,
429 const struct net_device *in,
430 const struct net_device *out,
431 int (*okfn)(struct sk_buff *))
433 struct ipv6hdr *hdr;
434 u32 pkt_len;
436 if (skb->len < sizeof(struct ipv6hdr))
437 goto inhdr_error;
439 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
440 goto inhdr_error;
442 hdr = skb->nh.ipv6h;
444 if (hdr->version != 6)
445 goto inhdr_error;
447 pkt_len = ntohs(hdr->payload_len);
449 if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
450 if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
451 goto inhdr_error;
452 if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
453 goto inhdr_error;
455 if (hdr->nexthdr == NEXTHDR_HOP && check_hbh_len(skb))
456 goto inhdr_error;
458 nf_bridge_put(skb->nf_bridge);
459 if (!nf_bridge_alloc(skb))
460 return NF_DROP;
461 if (!setup_pre_routing(skb))
462 return NF_DROP;
464 NF_HOOK(PF_INET6, NF_IP6_PRE_ROUTING, skb, skb->dev, NULL,
465 br_nf_pre_routing_finish_ipv6);
467 return NF_STOLEN;
469 inhdr_error:
470 return NF_DROP;
473 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
474 * Replicate the checks that IPv4 does on packet reception.
475 * Set skb->dev to the bridge device (i.e. parent of the
476 * receiving device) to make netfilter happy, the REDIRECT
477 * target in particular. Save the original destination IP
478 * address to be able to detect DNAT afterwards. */
479 static unsigned int br_nf_pre_routing(unsigned int hook, struct sk_buff **pskb,
480 const struct net_device *in,
481 const struct net_device *out,
482 int (*okfn)(struct sk_buff *))
484 struct iphdr *iph;
485 __u32 len;
486 struct sk_buff *skb = *pskb;
488 if (skb->protocol == htons(ETH_P_IPV6) || IS_VLAN_IPV6(skb)) {
489 #ifdef CONFIG_SYSCTL
490 if (!brnf_call_ip6tables)
491 return NF_ACCEPT;
492 #endif
493 if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL)
494 goto out;
496 if (skb->protocol == htons(ETH_P_8021Q)) {
497 skb_pull_rcsum(skb, VLAN_HLEN);
498 skb->nh.raw += VLAN_HLEN;
500 return br_nf_pre_routing_ipv6(hook, skb, in, out, okfn);
502 #ifdef CONFIG_SYSCTL
503 if (!brnf_call_iptables)
504 return NF_ACCEPT;
505 #endif
507 if (skb->protocol != htons(ETH_P_IP) && !IS_VLAN_IP(skb))
508 return NF_ACCEPT;
510 if ((skb = skb_share_check(*pskb, GFP_ATOMIC)) == NULL)
511 goto out;
513 if (skb->protocol == htons(ETH_P_8021Q)) {
514 skb_pull_rcsum(skb, VLAN_HLEN);
515 skb->nh.raw += VLAN_HLEN;
518 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
519 goto inhdr_error;
521 iph = skb->nh.iph;
522 if (iph->ihl < 5 || iph->version != 4)
523 goto inhdr_error;
525 if (!pskb_may_pull(skb, 4 * iph->ihl))
526 goto inhdr_error;
528 iph = skb->nh.iph;
529 if (ip_fast_csum((__u8 *) iph, iph->ihl) != 0)
530 goto inhdr_error;
532 len = ntohs(iph->tot_len);
533 if (skb->len < len || len < 4 * iph->ihl)
534 goto inhdr_error;
536 pskb_trim_rcsum(skb, len);
538 nf_bridge_put(skb->nf_bridge);
539 if (!nf_bridge_alloc(skb))
540 return NF_DROP;
541 if (!setup_pre_routing(skb))
542 return NF_DROP;
543 store_orig_dstaddr(skb);
545 NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, skb->dev, NULL,
546 br_nf_pre_routing_finish);
548 return NF_STOLEN;
550 inhdr_error:
551 // IP_INC_STATS_BH(IpInHdrErrors);
552 out:
553 return NF_DROP;
557 /* PF_BRIDGE/LOCAL_IN ************************************************/
558 /* The packet is locally destined, which requires a real
559 * dst_entry, so detach the fake one. On the way up, the
560 * packet would pass through PRE_ROUTING again (which already
561 * took place when the packet entered the bridge), but we
562 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
563 * prevent this from happening. */
564 static unsigned int br_nf_local_in(unsigned int hook, struct sk_buff **pskb,
565 const struct net_device *in,
566 const struct net_device *out,
567 int (*okfn)(struct sk_buff *))
569 struct sk_buff *skb = *pskb;
571 if (skb->dst == (struct dst_entry *)&__fake_rtable) {
572 dst_release(skb->dst);
573 skb->dst = NULL;
576 return NF_ACCEPT;
579 /* PF_BRIDGE/FORWARD *************************************************/
580 static int br_nf_forward_finish(struct sk_buff *skb)
582 struct nf_bridge_info *nf_bridge = skb->nf_bridge;
583 struct net_device *in;
585 if (skb->protocol != htons(ETH_P_ARP) && !IS_VLAN_ARP(skb)) {
586 in = nf_bridge->physindev;
587 if (nf_bridge->mask & BRNF_PKT_TYPE) {
588 skb->pkt_type = PACKET_OTHERHOST;
589 nf_bridge->mask ^= BRNF_PKT_TYPE;
591 } else {
592 in = *((struct net_device **)(skb->cb));
594 if (skb->protocol == htons(ETH_P_8021Q)) {
595 skb_push(skb, VLAN_HLEN);
596 skb->nh.raw -= VLAN_HLEN;
598 NF_HOOK_THRESH(PF_BRIDGE, NF_BR_FORWARD, skb, in,
599 skb->dev, br_forward_finish, 1);
600 return 0;
603 /* This is the 'purely bridged' case. For IP, we pass the packet to
604 * netfilter with indev and outdev set to the bridge device,
605 * but we are still able to filter on the 'real' indev/outdev
606 * because of the physdev module. For ARP, indev and outdev are the
607 * bridge ports. */
608 static unsigned int br_nf_forward_ip(unsigned int hook, struct sk_buff **pskb,
609 const struct net_device *in,
610 const struct net_device *out,
611 int (*okfn)(struct sk_buff *))
613 struct sk_buff *skb = *pskb;
614 struct nf_bridge_info *nf_bridge;
615 struct net_device *parent;
616 int pf;
618 if (!skb->nf_bridge)
619 return NF_ACCEPT;
621 parent = bridge_parent(out);
622 if (!parent)
623 return NF_DROP;
625 if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb))
626 pf = PF_INET;
627 else
628 pf = PF_INET6;
630 if (skb->protocol == htons(ETH_P_8021Q)) {
631 skb_pull(*pskb, VLAN_HLEN);
632 (*pskb)->nh.raw += VLAN_HLEN;
635 nf_bridge = skb->nf_bridge;
636 if (skb->pkt_type == PACKET_OTHERHOST) {
637 skb->pkt_type = PACKET_HOST;
638 nf_bridge->mask |= BRNF_PKT_TYPE;
641 /* The physdev module checks on this */
642 nf_bridge->mask |= BRNF_BRIDGED;
643 nf_bridge->physoutdev = skb->dev;
645 NF_HOOK(pf, NF_IP_FORWARD, skb, bridge_parent(in), parent,
646 br_nf_forward_finish);
648 return NF_STOLEN;
651 static unsigned int br_nf_forward_arp(unsigned int hook, struct sk_buff **pskb,
652 const struct net_device *in,
653 const struct net_device *out,
654 int (*okfn)(struct sk_buff *))
656 struct sk_buff *skb = *pskb;
657 struct net_device **d = (struct net_device **)(skb->cb);
659 #ifdef CONFIG_SYSCTL
660 if (!brnf_call_arptables)
661 return NF_ACCEPT;
662 #endif
664 if (skb->protocol != htons(ETH_P_ARP)) {
665 if (!IS_VLAN_ARP(skb))
666 return NF_ACCEPT;
667 skb_pull(*pskb, VLAN_HLEN);
668 (*pskb)->nh.raw += VLAN_HLEN;
671 if (skb->nh.arph->ar_pln != 4) {
672 if (IS_VLAN_ARP(skb)) {
673 skb_push(*pskb, VLAN_HLEN);
674 (*pskb)->nh.raw -= VLAN_HLEN;
676 return NF_ACCEPT;
678 *d = (struct net_device *)in;
679 NF_HOOK(NF_ARP, NF_ARP_FORWARD, skb, (struct net_device *)in,
680 (struct net_device *)out, br_nf_forward_finish);
682 return NF_STOLEN;
685 /* PF_BRIDGE/LOCAL_OUT ***********************************************
687 * This function sees both locally originated IP packets and forwarded
688 * IP packets (in both cases the destination device is a bridge
689 * device). It also sees bridged-and-DNAT'ed packets.
691 * If (nf_bridge->mask & BRNF_BRIDGED_DNAT) then the packet is bridged
692 * and we fake the PF_BRIDGE/FORWARD hook. The function br_nf_forward()
693 * will then fake the PF_INET/FORWARD hook. br_nf_local_out() has priority
694 * NF_BR_PRI_FIRST, so no relevant PF_BRIDGE/INPUT functions have been nor
695 * will be executed.
697 static unsigned int br_nf_local_out(unsigned int hook, struct sk_buff **pskb,
698 const struct net_device *in,
699 const struct net_device *out,
700 int (*okfn)(struct sk_buff *))
702 struct net_device *realindev;
703 struct sk_buff *skb = *pskb;
704 struct nf_bridge_info *nf_bridge;
706 if (!skb->nf_bridge)
707 return NF_ACCEPT;
709 nf_bridge = skb->nf_bridge;
710 if (!(nf_bridge->mask & BRNF_BRIDGED_DNAT))
711 return NF_ACCEPT;
713 /* Bridged, take PF_BRIDGE/FORWARD.
714 * (see big note in front of br_nf_pre_routing_finish) */
715 nf_bridge->physoutdev = skb->dev;
716 realindev = nf_bridge->physindev;
718 if (nf_bridge->mask & BRNF_PKT_TYPE) {
719 skb->pkt_type = PACKET_OTHERHOST;
720 nf_bridge->mask ^= BRNF_PKT_TYPE;
722 if (skb->protocol == htons(ETH_P_8021Q)) {
723 skb_push(skb, VLAN_HLEN);
724 skb->nh.raw -= VLAN_HLEN;
727 NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, realindev, skb->dev,
728 br_forward_finish);
729 return NF_STOLEN;
732 static int br_nf_dev_queue_xmit(struct sk_buff *skb)
734 if (skb->protocol == htons(ETH_P_IP) &&
735 skb->len > skb->dev->mtu &&
736 !skb_is_gso(skb))
737 return ip_fragment(skb, br_dev_queue_push_xmit);
738 else
739 return br_dev_queue_push_xmit(skb);
742 /* PF_BRIDGE/POST_ROUTING ********************************************/
743 static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb,
744 const struct net_device *in,
745 const struct net_device *out,
746 int (*okfn)(struct sk_buff *))
748 struct sk_buff *skb = *pskb;
749 struct nf_bridge_info *nf_bridge = (*pskb)->nf_bridge;
750 struct net_device *realoutdev = bridge_parent(skb->dev);
751 int pf;
753 #ifdef CONFIG_NETFILTER_DEBUG
754 /* Be very paranoid. This probably won't happen anymore, but let's
755 * keep the check just to be sure... */
756 if (skb->mac.raw < skb->head || skb->mac.raw + ETH_HLEN > skb->data) {
757 printk(KERN_CRIT "br_netfilter: Argh!! br_nf_post_routing: "
758 "bad mac.raw pointer.\n");
759 goto print_error;
761 #endif
763 if (!nf_bridge)
764 return NF_ACCEPT;
766 if (!realoutdev)
767 return NF_DROP;
769 if (skb->protocol == htons(ETH_P_IP) || IS_VLAN_IP(skb))
770 pf = PF_INET;
771 else
772 pf = PF_INET6;
774 #ifdef CONFIG_NETFILTER_DEBUG
775 if (skb->dst == NULL) {
776 printk(KERN_INFO "br_netfilter post_routing: skb->dst == NULL\n");
777 goto print_error;
779 #endif
781 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
782 * about the value of skb->pkt_type. */
783 if (skb->pkt_type == PACKET_OTHERHOST) {
784 skb->pkt_type = PACKET_HOST;
785 nf_bridge->mask |= BRNF_PKT_TYPE;
788 if (skb->protocol == htons(ETH_P_8021Q)) {
789 skb_pull(skb, VLAN_HLEN);
790 skb->nh.raw += VLAN_HLEN;
793 nf_bridge_save_header(skb);
795 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
796 if (nf_bridge->netoutdev)
797 realoutdev = nf_bridge->netoutdev;
798 #endif
799 NF_HOOK(pf, NF_IP_POST_ROUTING, skb, NULL, realoutdev,
800 br_nf_dev_queue_xmit);
802 return NF_STOLEN;
804 #ifdef CONFIG_NETFILTER_DEBUG
805 print_error:
806 if (skb->dev != NULL) {
807 printk("[%s]", skb->dev->name);
808 if (realoutdev)
809 printk("[%s]", realoutdev->name);
811 printk(" head:%p, raw:%p, data:%p\n", skb->head, skb->mac.raw,
812 skb->data);
813 dump_stack();
814 return NF_ACCEPT;
815 #endif
818 /* IP/SABOTAGE *****************************************************/
819 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
820 * for the second time. */
821 static unsigned int ip_sabotage_in(unsigned int hook, struct sk_buff **pskb,
822 const struct net_device *in,
823 const struct net_device *out,
824 int (*okfn)(struct sk_buff *))
826 if ((*pskb)->nf_bridge &&
827 !((*pskb)->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
828 return NF_STOP;
831 return NF_ACCEPT;
834 /* For br_nf_local_out we need (prio = NF_BR_PRI_FIRST), to insure that innocent
835 * PF_BRIDGE/NF_BR_LOCAL_OUT functions don't get bridged traffic as input.
836 * For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
837 * ip_refrag() can return NF_STOLEN. */
838 static struct nf_hook_ops br_nf_ops[] = {
839 { .hook = br_nf_pre_routing,
840 .owner = THIS_MODULE,
841 .pf = PF_BRIDGE,
842 .hooknum = NF_BR_PRE_ROUTING,
843 .priority = NF_BR_PRI_BRNF, },
844 { .hook = br_nf_local_in,
845 .owner = THIS_MODULE,
846 .pf = PF_BRIDGE,
847 .hooknum = NF_BR_LOCAL_IN,
848 .priority = NF_BR_PRI_BRNF, },
849 { .hook = br_nf_forward_ip,
850 .owner = THIS_MODULE,
851 .pf = PF_BRIDGE,
852 .hooknum = NF_BR_FORWARD,
853 .priority = NF_BR_PRI_BRNF - 1, },
854 { .hook = br_nf_forward_arp,
855 .owner = THIS_MODULE,
856 .pf = PF_BRIDGE,
857 .hooknum = NF_BR_FORWARD,
858 .priority = NF_BR_PRI_BRNF, },
859 { .hook = br_nf_local_out,
860 .owner = THIS_MODULE,
861 .pf = PF_BRIDGE,
862 .hooknum = NF_BR_LOCAL_OUT,
863 .priority = NF_BR_PRI_FIRST, },
864 { .hook = br_nf_post_routing,
865 .owner = THIS_MODULE,
866 .pf = PF_BRIDGE,
867 .hooknum = NF_BR_POST_ROUTING,
868 .priority = NF_BR_PRI_LAST, },
869 { .hook = ip_sabotage_in,
870 .owner = THIS_MODULE,
871 .pf = PF_INET,
872 .hooknum = NF_IP_PRE_ROUTING,
873 .priority = NF_IP_PRI_FIRST, },
874 { .hook = ip_sabotage_in,
875 .owner = THIS_MODULE,
876 .pf = PF_INET6,
877 .hooknum = NF_IP6_PRE_ROUTING,
878 .priority = NF_IP6_PRI_FIRST, },
881 #ifdef CONFIG_SYSCTL
882 static
883 int brnf_sysctl_call_tables(ctl_table * ctl, int write, struct file *filp,
884 void __user * buffer, size_t * lenp, loff_t * ppos)
886 int ret;
888 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos);
890 if (write && *(int *)(ctl->data))
891 *(int *)(ctl->data) = 1;
892 return ret;
895 static ctl_table brnf_table[] = {
897 .ctl_name = NET_BRIDGE_NF_CALL_ARPTABLES,
898 .procname = "bridge-nf-call-arptables",
899 .data = &brnf_call_arptables,
900 .maxlen = sizeof(int),
901 .mode = 0644,
902 .proc_handler = &brnf_sysctl_call_tables,
905 .ctl_name = NET_BRIDGE_NF_CALL_IPTABLES,
906 .procname = "bridge-nf-call-iptables",
907 .data = &brnf_call_iptables,
908 .maxlen = sizeof(int),
909 .mode = 0644,
910 .proc_handler = &brnf_sysctl_call_tables,
913 .ctl_name = NET_BRIDGE_NF_CALL_IP6TABLES,
914 .procname = "bridge-nf-call-ip6tables",
915 .data = &brnf_call_ip6tables,
916 .maxlen = sizeof(int),
917 .mode = 0644,
918 .proc_handler = &brnf_sysctl_call_tables,
921 .ctl_name = NET_BRIDGE_NF_FILTER_VLAN_TAGGED,
922 .procname = "bridge-nf-filter-vlan-tagged",
923 .data = &brnf_filter_vlan_tagged,
924 .maxlen = sizeof(int),
925 .mode = 0644,
926 .proc_handler = &brnf_sysctl_call_tables,
928 { .ctl_name = 0 }
931 static ctl_table brnf_bridge_table[] = {
933 .ctl_name = NET_BRIDGE,
934 .procname = "bridge",
935 .mode = 0555,
936 .child = brnf_table,
938 { .ctl_name = 0 }
941 static ctl_table brnf_net_table[] = {
943 .ctl_name = CTL_NET,
944 .procname = "net",
945 .mode = 0555,
946 .child = brnf_bridge_table,
948 { .ctl_name = 0 }
950 #endif
952 int br_netfilter_init(void)
954 int i;
956 for (i = 0; i < ARRAY_SIZE(br_nf_ops); i++) {
957 int ret;
959 if ((ret = nf_register_hook(&br_nf_ops[i])) >= 0)
960 continue;
962 while (i--)
963 nf_unregister_hook(&br_nf_ops[i]);
965 return ret;
968 #ifdef CONFIG_SYSCTL
969 brnf_sysctl_header = register_sysctl_table(brnf_net_table, 0);
970 if (brnf_sysctl_header == NULL) {
971 printk(KERN_WARNING
972 "br_netfilter: can't register to sysctl.\n");
973 for (i = 0; i < ARRAY_SIZE(br_nf_ops); i++)
974 nf_unregister_hook(&br_nf_ops[i]);
975 return -EFAULT;
977 #endif
979 printk(KERN_NOTICE "Bridge firewalling registered\n");
981 return 0;
984 void br_netfilter_fini(void)
986 int i;
988 for (i = ARRAY_SIZE(br_nf_ops) - 1; i >= 0; i--)
989 nf_unregister_hook(&br_nf_ops[i]);
990 #ifdef CONFIG_SYSCTL
991 unregister_sysctl_table(brnf_sysctl_header);
992 #endif