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");