3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
7 * Bart De Schuymer (maintainer) <bdschuym@pandora.be>
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
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>
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>
41 #include <net/route.h>
43 #include <asm/uaccess.h>
44 #include "br_private.h"
46 #include <linux/sysctl.h>
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) = ip_hdr(skb)->daddr)
52 #define dnat_took_place(skb) (skb_origaddr(skb) != ip_hdr(skb)->daddr)
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;
61 #define brnf_filter_vlan_tagged 1
64 static inline __be16
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
= {
99 .__refcnt
= ATOMIC_INIT(1),
100 .dev
= &__fake_net_device
,
101 .path
= &__fake_rtable
.u
.dst
,
102 .metrics
= {[RTAX_MTU
- 1] = 1500},
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 skb_copy_from_linear_data_offset(skb
, -header_size
,
133 skb
->nf_bridge
->data
, header_size
);
137 * When forwarding bridge frames, we save a copy of the original
138 * header before processing.
140 int nf_bridge_copy_header(struct sk_buff
*skb
)
143 int header_size
= ETH_HLEN
;
145 if (skb
->protocol
== htons(ETH_P_8021Q
))
146 header_size
+= VLAN_HLEN
;
148 err
= skb_cow(skb
, header_size
);
152 skb_copy_to_linear_data_offset(skb
, -header_size
,
153 skb
->nf_bridge
->data
, header_size
);
155 if (skb
->protocol
== htons(ETH_P_8021Q
))
156 __skb_push(skb
, VLAN_HLEN
);
160 /* PF_BRIDGE/PRE_ROUTING *********************************************/
161 /* Undo the changes made for ip6tables PREROUTING and continue the
162 * bridge PRE_ROUTING hook. */
163 static int br_nf_pre_routing_finish_ipv6(struct sk_buff
*skb
)
165 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
167 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
168 skb
->pkt_type
= PACKET_OTHERHOST
;
169 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
171 nf_bridge
->mask
^= BRNF_NF_BRIDGE_PREROUTING
;
173 skb
->dst
= (struct dst_entry
*)&__fake_rtable
;
176 skb
->dev
= nf_bridge
->physindev
;
177 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
178 skb_push(skb
, VLAN_HLEN
);
179 skb
->network_header
-= VLAN_HLEN
;
181 NF_HOOK_THRESH(PF_BRIDGE
, NF_BR_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
182 br_handle_frame_finish
, 1);
187 static void __br_dnat_complain(void)
189 static unsigned long last_complaint
;
191 if (jiffies
- last_complaint
>= 5 * HZ
) {
192 printk(KERN_WARNING
"Performing cross-bridge DNAT requires IP "
193 "forwarding to be enabled\n");
194 last_complaint
= jiffies
;
198 /* This requires some explaining. If DNAT has taken place,
199 * we will need to fix up the destination Ethernet address,
200 * and this is a tricky process.
202 * There are two cases to consider:
203 * 1. The packet was DNAT'ed to a device in the same bridge
204 * port group as it was received on. We can still bridge
206 * 2. The packet was DNAT'ed to a different device, either
207 * a non-bridged device or another bridge port group.
208 * The packet will need to be routed.
210 * The correct way of distinguishing between these two cases is to
211 * call ip_route_input() and to look at skb->dst->dev, which is
212 * changed to the destination device if ip_route_input() succeeds.
214 * Let us first consider the case that ip_route_input() succeeds:
216 * If skb->dst->dev equals the logical bridge device the packet
217 * came in on, we can consider this bridging. We then call
218 * skb->dst->output() which will make the packet enter br_nf_local_out()
219 * not much later. In that function it is assured that the iptables
220 * FORWARD chain is traversed for the packet.
222 * Otherwise, the packet is considered to be routed and we just
223 * change the destination MAC address so that the packet will
224 * later be passed up to the IP stack to be routed. For a redirected
225 * packet, ip_route_input() will give back the localhost as output device,
226 * which differs from the bridge device.
228 * Let us now consider the case that ip_route_input() fails:
230 * This can be because the destination address is martian, in which case
231 * the packet will be dropped.
232 * After a "echo '0' > /proc/sys/net/ipv4/ip_forward" ip_route_input()
233 * will fail, while __ip_route_output_key() will return success. The source
234 * address for __ip_route_output_key() is set to zero, so __ip_route_output_key
235 * thinks we're handling a locally generated packet and won't care
236 * if IP forwarding is allowed. We send a warning message to the users's
237 * log telling her to put IP forwarding on.
239 * ip_route_input() will also fail if there is no route available.
240 * In that case we just drop the packet.
242 * --Lennert, 20020411
243 * --Bart, 20020416 (updated)
244 * --Bart, 20021007 (updated)
245 * --Bart, 20062711 (updated) */
246 static int br_nf_pre_routing_finish_bridge(struct sk_buff
*skb
)
248 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
249 skb
->pkt_type
= PACKET_HOST
;
250 skb
->nf_bridge
->mask
|= BRNF_PKT_TYPE
;
252 skb
->nf_bridge
->mask
^= BRNF_NF_BRIDGE_PREROUTING
;
254 skb
->dev
= bridge_parent(skb
->dev
);
258 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
259 skb_pull(skb
, VLAN_HLEN
);
260 skb
->network_header
+= VLAN_HLEN
;
262 skb
->dst
->output(skb
);
267 static int br_nf_pre_routing_finish(struct sk_buff
*skb
)
269 struct net_device
*dev
= skb
->dev
;
270 struct iphdr
*iph
= ip_hdr(skb
);
271 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
274 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
275 skb
->pkt_type
= PACKET_OTHERHOST
;
276 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
278 nf_bridge
->mask
^= BRNF_NF_BRIDGE_PREROUTING
;
279 if (dnat_took_place(skb
)) {
280 if ((err
= ip_route_input(skb
, iph
->daddr
, iph
->saddr
, iph
->tos
, dev
))) {
287 .tos
= RT_TOS(iph
->tos
) },
291 struct in_device
*in_dev
= in_dev_get(dev
);
293 /* If err equals -EHOSTUNREACH the error is due to a
294 * martian destination or due to the fact that
295 * forwarding is disabled. For most martian packets,
296 * ip_route_output_key() will fail. It won't fail for 2 types of
297 * martian destinations: loopback destinations and destination
298 * 0.0.0.0. In both cases the packet will be dropped because the
299 * destination is the loopback device and not the bridge. */
300 if (err
!= -EHOSTUNREACH
|| !in_dev
|| IN_DEV_FORWARD(in_dev
))
303 if (!ip_route_output_key(&rt
, &fl
)) {
304 /* - Bridged-and-DNAT'ed traffic doesn't
305 * require ip_forwarding. */
306 if (((struct dst_entry
*)rt
)->dev
== dev
) {
307 skb
->dst
= (struct dst_entry
*)rt
;
310 /* we are sure that forwarding is disabled, so printing
311 * this message is no problem. Note that the packet could
312 * still have a martian destination address, in which case
313 * the packet could be dropped even if forwarding were enabled */
314 __br_dnat_complain();
315 dst_release((struct dst_entry
*)rt
);
321 if (skb
->dst
->dev
== dev
) {
323 /* Tell br_nf_local_out this is a
325 nf_bridge
->mask
|= BRNF_BRIDGED_DNAT
;
326 skb
->dev
= nf_bridge
->physindev
;
328 htons(ETH_P_8021Q
)) {
329 skb_push(skb
, VLAN_HLEN
);
330 skb
->network_header
-= VLAN_HLEN
;
332 NF_HOOK_THRESH(PF_BRIDGE
, NF_BR_PRE_ROUTING
,
334 br_nf_pre_routing_finish_bridge
,
338 memcpy(eth_hdr(skb
)->h_dest
, dev
->dev_addr
, ETH_ALEN
);
339 skb
->pkt_type
= PACKET_HOST
;
342 skb
->dst
= (struct dst_entry
*)&__fake_rtable
;
346 skb
->dev
= nf_bridge
->physindev
;
347 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
348 skb_push(skb
, VLAN_HLEN
);
349 skb
->network_header
-= VLAN_HLEN
;
351 NF_HOOK_THRESH(PF_BRIDGE
, NF_BR_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
352 br_handle_frame_finish
, 1);
357 /* Some common code for IPv4/IPv6 */
358 static struct net_device
*setup_pre_routing(struct sk_buff
*skb
)
360 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
362 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
363 skb
->pkt_type
= PACKET_HOST
;
364 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
367 nf_bridge
->mask
|= BRNF_NF_BRIDGE_PREROUTING
;
368 nf_bridge
->physindev
= skb
->dev
;
369 skb
->dev
= bridge_parent(skb
->dev
);
374 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
375 static int check_hbh_len(struct sk_buff
*skb
)
377 unsigned char *raw
= (u8
*)(ipv6_hdr(skb
) + 1);
379 const unsigned char *nh
= skb_network_header(skb
);
381 int len
= (raw
[1] + 1) << 3;
383 if ((raw
+ len
) - skb
->data
> skb_headlen(skb
))
390 int optlen
= nh
[off
+ 1] + 2;
401 if (nh
[off
+ 1] != 4 || (off
& 3) != 2)
403 pkt_len
= ntohl(*(__be32
*) (nh
+ off
+ 2));
404 if (pkt_len
<= IPV6_MAXPLEN
||
405 ipv6_hdr(skb
)->payload_len
)
407 if (pkt_len
> skb
->len
- sizeof(struct ipv6hdr
))
409 if (pskb_trim_rcsum(skb
,
410 pkt_len
+ sizeof(struct ipv6hdr
)))
412 nh
= skb_network_header(skb
);
429 /* Replicate the checks that IPv6 does on packet reception and pass the packet
430 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
431 static unsigned int br_nf_pre_routing_ipv6(unsigned int hook
,
433 const struct net_device
*in
,
434 const struct net_device
*out
,
435 int (*okfn
)(struct sk_buff
*))
440 if (skb
->len
< sizeof(struct ipv6hdr
))
443 if (!pskb_may_pull(skb
, sizeof(struct ipv6hdr
)))
448 if (hdr
->version
!= 6)
451 pkt_len
= ntohs(hdr
->payload_len
);
453 if (pkt_len
|| hdr
->nexthdr
!= NEXTHDR_HOP
) {
454 if (pkt_len
+ sizeof(struct ipv6hdr
) > skb
->len
)
456 if (pskb_trim_rcsum(skb
, pkt_len
+ sizeof(struct ipv6hdr
)))
459 if (hdr
->nexthdr
== NEXTHDR_HOP
&& check_hbh_len(skb
))
462 nf_bridge_put(skb
->nf_bridge
);
463 if (!nf_bridge_alloc(skb
))
465 if (!setup_pre_routing(skb
))
468 NF_HOOK(PF_INET6
, NF_IP6_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
469 br_nf_pre_routing_finish_ipv6
);
477 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
478 * Replicate the checks that IPv4 does on packet reception.
479 * Set skb->dev to the bridge device (i.e. parent of the
480 * receiving device) to make netfilter happy, the REDIRECT
481 * target in particular. Save the original destination IP
482 * address to be able to detect DNAT afterwards. */
483 static unsigned int br_nf_pre_routing(unsigned int hook
, struct sk_buff
**pskb
,
484 const struct net_device
*in
,
485 const struct net_device
*out
,
486 int (*okfn
)(struct sk_buff
*))
490 struct sk_buff
*skb
= *pskb
;
492 if (skb
->protocol
== htons(ETH_P_IPV6
) || IS_VLAN_IPV6(skb
)) {
494 if (!brnf_call_ip6tables
)
497 if ((skb
= skb_share_check(*pskb
, GFP_ATOMIC
)) == NULL
)
500 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
501 skb_pull_rcsum(skb
, VLAN_HLEN
);
502 skb
->network_header
+= VLAN_HLEN
;
504 return br_nf_pre_routing_ipv6(hook
, skb
, in
, out
, okfn
);
507 if (!brnf_call_iptables
)
511 if (skb
->protocol
!= htons(ETH_P_IP
) && !IS_VLAN_IP(skb
))
514 if ((skb
= skb_share_check(*pskb
, GFP_ATOMIC
)) == NULL
)
517 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
518 skb_pull_rcsum(skb
, VLAN_HLEN
);
519 skb
->network_header
+= VLAN_HLEN
;
522 if (!pskb_may_pull(skb
, sizeof(struct iphdr
)))
526 if (iph
->ihl
< 5 || iph
->version
!= 4)
529 if (!pskb_may_pull(skb
, 4 * iph
->ihl
))
533 if (ip_fast_csum((__u8
*) iph
, iph
->ihl
) != 0)
536 len
= ntohs(iph
->tot_len
);
537 if (skb
->len
< len
|| len
< 4 * iph
->ihl
)
540 pskb_trim_rcsum(skb
, len
);
542 nf_bridge_put(skb
->nf_bridge
);
543 if (!nf_bridge_alloc(skb
))
545 if (!setup_pre_routing(skb
))
547 store_orig_dstaddr(skb
);
549 NF_HOOK(PF_INET
, NF_IP_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
550 br_nf_pre_routing_finish
);
555 // IP_INC_STATS_BH(IpInHdrErrors);
561 /* PF_BRIDGE/LOCAL_IN ************************************************/
562 /* The packet is locally destined, which requires a real
563 * dst_entry, so detach the fake one. On the way up, the
564 * packet would pass through PRE_ROUTING again (which already
565 * took place when the packet entered the bridge), but we
566 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
567 * prevent this from happening. */
568 static unsigned int br_nf_local_in(unsigned int hook
, struct sk_buff
**pskb
,
569 const struct net_device
*in
,
570 const struct net_device
*out
,
571 int (*okfn
)(struct sk_buff
*))
573 struct sk_buff
*skb
= *pskb
;
575 if (skb
->dst
== (struct dst_entry
*)&__fake_rtable
) {
576 dst_release(skb
->dst
);
583 /* PF_BRIDGE/FORWARD *************************************************/
584 static int br_nf_forward_finish(struct sk_buff
*skb
)
586 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
587 struct net_device
*in
;
589 if (skb
->protocol
!= htons(ETH_P_ARP
) && !IS_VLAN_ARP(skb
)) {
590 in
= nf_bridge
->physindev
;
591 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
592 skb
->pkt_type
= PACKET_OTHERHOST
;
593 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
596 in
= *((struct net_device
**)(skb
->cb
));
598 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
599 skb_push(skb
, VLAN_HLEN
);
600 skb
->network_header
-= VLAN_HLEN
;
602 NF_HOOK_THRESH(PF_BRIDGE
, NF_BR_FORWARD
, skb
, in
,
603 skb
->dev
, br_forward_finish
, 1);
607 /* This is the 'purely bridged' case. For IP, we pass the packet to
608 * netfilter with indev and outdev set to the bridge device,
609 * but we are still able to filter on the 'real' indev/outdev
610 * because of the physdev module. For ARP, indev and outdev are the
612 static unsigned int br_nf_forward_ip(unsigned int hook
, struct sk_buff
**pskb
,
613 const struct net_device
*in
,
614 const struct net_device
*out
,
615 int (*okfn
)(struct sk_buff
*))
617 struct sk_buff
*skb
= *pskb
;
618 struct nf_bridge_info
*nf_bridge
;
619 struct net_device
*parent
;
625 parent
= bridge_parent(out
);
629 if (skb
->protocol
== htons(ETH_P_IP
) || IS_VLAN_IP(skb
))
634 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
635 skb_pull(*pskb
, VLAN_HLEN
);
636 (*pskb
)->network_header
+= VLAN_HLEN
;
639 nf_bridge
= skb
->nf_bridge
;
640 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
641 skb
->pkt_type
= PACKET_HOST
;
642 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
645 /* The physdev module checks on this */
646 nf_bridge
->mask
|= BRNF_BRIDGED
;
647 nf_bridge
->physoutdev
= skb
->dev
;
649 NF_HOOK(pf
, NF_IP_FORWARD
, skb
, bridge_parent(in
), parent
,
650 br_nf_forward_finish
);
655 static unsigned int br_nf_forward_arp(unsigned int hook
, struct sk_buff
**pskb
,
656 const struct net_device
*in
,
657 const struct net_device
*out
,
658 int (*okfn
)(struct sk_buff
*))
660 struct sk_buff
*skb
= *pskb
;
661 struct net_device
**d
= (struct net_device
**)(skb
->cb
);
664 if (!brnf_call_arptables
)
668 if (skb
->protocol
!= htons(ETH_P_ARP
)) {
669 if (!IS_VLAN_ARP(skb
))
671 skb_pull(*pskb
, VLAN_HLEN
);
672 (*pskb
)->network_header
+= VLAN_HLEN
;
675 if (arp_hdr(skb
)->ar_pln
!= 4) {
676 if (IS_VLAN_ARP(skb
)) {
677 skb_push(*pskb
, VLAN_HLEN
);
678 (*pskb
)->network_header
-= VLAN_HLEN
;
682 *d
= (struct net_device
*)in
;
683 NF_HOOK(NF_ARP
, NF_ARP_FORWARD
, skb
, (struct net_device
*)in
,
684 (struct net_device
*)out
, br_nf_forward_finish
);
689 /* PF_BRIDGE/LOCAL_OUT ***********************************************
691 * This function sees both locally originated IP packets and forwarded
692 * IP packets (in both cases the destination device is a bridge
693 * device). It also sees bridged-and-DNAT'ed packets.
695 * If (nf_bridge->mask & BRNF_BRIDGED_DNAT) then the packet is bridged
696 * and we fake the PF_BRIDGE/FORWARD hook. The function br_nf_forward()
697 * will then fake the PF_INET/FORWARD hook. br_nf_local_out() has priority
698 * NF_BR_PRI_FIRST, so no relevant PF_BRIDGE/INPUT functions have been nor
701 static unsigned int br_nf_local_out(unsigned int hook
, struct sk_buff
**pskb
,
702 const struct net_device
*in
,
703 const struct net_device
*out
,
704 int (*okfn
)(struct sk_buff
*))
706 struct net_device
*realindev
;
707 struct sk_buff
*skb
= *pskb
;
708 struct nf_bridge_info
*nf_bridge
;
713 nf_bridge
= skb
->nf_bridge
;
714 if (!(nf_bridge
->mask
& BRNF_BRIDGED_DNAT
))
717 /* Bridged, take PF_BRIDGE/FORWARD.
718 * (see big note in front of br_nf_pre_routing_finish) */
719 nf_bridge
->physoutdev
= skb
->dev
;
720 realindev
= nf_bridge
->physindev
;
722 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
723 skb
->pkt_type
= PACKET_OTHERHOST
;
724 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
726 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
727 skb_push(skb
, VLAN_HLEN
);
728 skb
->network_header
-= VLAN_HLEN
;
731 NF_HOOK(PF_BRIDGE
, NF_BR_FORWARD
, skb
, realindev
, skb
->dev
,
736 static int br_nf_dev_queue_xmit(struct sk_buff
*skb
)
738 if (skb
->protocol
== htons(ETH_P_IP
) &&
739 skb
->len
> skb
->dev
->mtu
&&
741 return ip_fragment(skb
, br_dev_queue_push_xmit
);
743 return br_dev_queue_push_xmit(skb
);
746 /* PF_BRIDGE/POST_ROUTING ********************************************/
747 static unsigned int br_nf_post_routing(unsigned int hook
, struct sk_buff
**pskb
,
748 const struct net_device
*in
,
749 const struct net_device
*out
,
750 int (*okfn
)(struct sk_buff
*))
752 struct sk_buff
*skb
= *pskb
;
753 struct nf_bridge_info
*nf_bridge
= (*pskb
)->nf_bridge
;
754 struct net_device
*realoutdev
= bridge_parent(skb
->dev
);
757 #ifdef CONFIG_NETFILTER_DEBUG
758 /* Be very paranoid. This probably won't happen anymore, but let's
759 * keep the check just to be sure... */
760 if (skb_mac_header(skb
) < skb
->head
||
761 skb_mac_header(skb
) + ETH_HLEN
> skb
->data
) {
762 printk(KERN_CRIT
"br_netfilter: Argh!! br_nf_post_routing: "
763 "bad mac.raw pointer.\n");
774 if (skb
->protocol
== htons(ETH_P_IP
) || IS_VLAN_IP(skb
))
779 #ifdef CONFIG_NETFILTER_DEBUG
780 if (skb
->dst
== NULL
) {
781 printk(KERN_INFO
"br_netfilter post_routing: skb->dst == NULL\n");
786 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
787 * about the value of skb->pkt_type. */
788 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
789 skb
->pkt_type
= PACKET_HOST
;
790 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
793 if (skb
->protocol
== htons(ETH_P_8021Q
)) {
794 skb_pull(skb
, VLAN_HLEN
);
795 skb
->network_header
+= VLAN_HLEN
;
798 nf_bridge_save_header(skb
);
800 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
801 if (nf_bridge
->netoutdev
)
802 realoutdev
= nf_bridge
->netoutdev
;
804 NF_HOOK(pf
, NF_IP_POST_ROUTING
, skb
, NULL
, realoutdev
,
805 br_nf_dev_queue_xmit
);
809 #ifdef CONFIG_NETFILTER_DEBUG
811 if (skb
->dev
!= NULL
) {
812 printk("[%s]", skb
->dev
->name
);
814 printk("[%s]", realoutdev
->name
);
816 printk(" head:%p, raw:%p, data:%p\n", skb
->head
, skb_mac_header(skb
),
823 /* IP/SABOTAGE *****************************************************/
824 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
825 * for the second time. */
826 static unsigned int ip_sabotage_in(unsigned int hook
, struct sk_buff
**pskb
,
827 const struct net_device
*in
,
828 const struct net_device
*out
,
829 int (*okfn
)(struct sk_buff
*))
831 if ((*pskb
)->nf_bridge
&&
832 !((*pskb
)->nf_bridge
->mask
& BRNF_NF_BRIDGE_PREROUTING
)) {
839 /* For br_nf_local_out we need (prio = NF_BR_PRI_FIRST), to insure that innocent
840 * PF_BRIDGE/NF_BR_LOCAL_OUT functions don't get bridged traffic as input.
841 * For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
842 * ip_refrag() can return NF_STOLEN. */
843 static struct nf_hook_ops br_nf_ops
[] = {
844 { .hook
= br_nf_pre_routing
,
845 .owner
= THIS_MODULE
,
847 .hooknum
= NF_BR_PRE_ROUTING
,
848 .priority
= NF_BR_PRI_BRNF
, },
849 { .hook
= br_nf_local_in
,
850 .owner
= THIS_MODULE
,
852 .hooknum
= NF_BR_LOCAL_IN
,
853 .priority
= NF_BR_PRI_BRNF
, },
854 { .hook
= br_nf_forward_ip
,
855 .owner
= THIS_MODULE
,
857 .hooknum
= NF_BR_FORWARD
,
858 .priority
= NF_BR_PRI_BRNF
- 1, },
859 { .hook
= br_nf_forward_arp
,
860 .owner
= THIS_MODULE
,
862 .hooknum
= NF_BR_FORWARD
,
863 .priority
= NF_BR_PRI_BRNF
, },
864 { .hook
= br_nf_local_out
,
865 .owner
= THIS_MODULE
,
867 .hooknum
= NF_BR_LOCAL_OUT
,
868 .priority
= NF_BR_PRI_FIRST
, },
869 { .hook
= br_nf_post_routing
,
870 .owner
= THIS_MODULE
,
872 .hooknum
= NF_BR_POST_ROUTING
,
873 .priority
= NF_BR_PRI_LAST
, },
874 { .hook
= ip_sabotage_in
,
875 .owner
= THIS_MODULE
,
877 .hooknum
= NF_IP_PRE_ROUTING
,
878 .priority
= NF_IP_PRI_FIRST
, },
879 { .hook
= ip_sabotage_in
,
880 .owner
= THIS_MODULE
,
882 .hooknum
= NF_IP6_PRE_ROUTING
,
883 .priority
= NF_IP6_PRI_FIRST
, },
888 int brnf_sysctl_call_tables(ctl_table
* ctl
, int write
, struct file
*filp
,
889 void __user
* buffer
, size_t * lenp
, loff_t
* ppos
)
893 ret
= proc_dointvec(ctl
, write
, filp
, buffer
, lenp
, ppos
);
895 if (write
&& *(int *)(ctl
->data
))
896 *(int *)(ctl
->data
) = 1;
900 static ctl_table brnf_table
[] = {
902 .ctl_name
= NET_BRIDGE_NF_CALL_ARPTABLES
,
903 .procname
= "bridge-nf-call-arptables",
904 .data
= &brnf_call_arptables
,
905 .maxlen
= sizeof(int),
907 .proc_handler
= &brnf_sysctl_call_tables
,
910 .ctl_name
= NET_BRIDGE_NF_CALL_IPTABLES
,
911 .procname
= "bridge-nf-call-iptables",
912 .data
= &brnf_call_iptables
,
913 .maxlen
= sizeof(int),
915 .proc_handler
= &brnf_sysctl_call_tables
,
918 .ctl_name
= NET_BRIDGE_NF_CALL_IP6TABLES
,
919 .procname
= "bridge-nf-call-ip6tables",
920 .data
= &brnf_call_ip6tables
,
921 .maxlen
= sizeof(int),
923 .proc_handler
= &brnf_sysctl_call_tables
,
926 .ctl_name
= NET_BRIDGE_NF_FILTER_VLAN_TAGGED
,
927 .procname
= "bridge-nf-filter-vlan-tagged",
928 .data
= &brnf_filter_vlan_tagged
,
929 .maxlen
= sizeof(int),
931 .proc_handler
= &brnf_sysctl_call_tables
,
936 static ctl_table brnf_bridge_table
[] = {
938 .ctl_name
= NET_BRIDGE
,
939 .procname
= "bridge",
946 static ctl_table brnf_net_table
[] = {
951 .child
= brnf_bridge_table
,
957 int __init
br_netfilter_init(void)
961 ret
= nf_register_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
965 brnf_sysctl_header
= register_sysctl_table(brnf_net_table
);
966 if (brnf_sysctl_header
== NULL
) {
968 "br_netfilter: can't register to sysctl.\n");
969 nf_unregister_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
973 printk(KERN_NOTICE
"Bridge firewalling registered\n");
977 void br_netfilter_fini(void)
979 nf_unregister_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
981 unregister_sysctl_table(brnf_sysctl_header
);