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 void fake_update_pmtu(struct dst_entry
*dst
, struct sock
*sk
,
115 struct sk_buff
*skb
, u32 mtu
)
119 static void fake_redirect(struct dst_entry
*dst
, struct sock
*sk
,
124 static u32
*fake_cow_metrics(struct dst_entry
*dst
, unsigned long old
)
129 static struct neighbour
*fake_neigh_lookup(const struct dst_entry
*dst
,
136 static unsigned int fake_mtu(const struct dst_entry
*dst
)
138 return dst
->dev
->mtu
;
141 static struct dst_ops fake_dst_ops
= {
143 .protocol
= cpu_to_be16(ETH_P_IP
),
144 .update_pmtu
= fake_update_pmtu
,
145 .redirect
= fake_redirect
,
146 .cow_metrics
= fake_cow_metrics
,
147 .neigh_lookup
= fake_neigh_lookup
,
152 * Initialize bogus route table used to keep netfilter happy.
153 * Currently, we fill in the PMTU entry because netfilter
154 * refragmentation needs it, and the rt_flags entry because
155 * ipt_REJECT needs it. Future netfilter modules might
156 * require us to fill additional fields.
158 static const u32 br_dst_default_metrics
[RTAX_MAX
] = {
159 [RTAX_MTU
- 1] = 1500,
162 void br_netfilter_rtable_init(struct net_bridge
*br
)
164 struct rtable
*rt
= &br
->fake_rtable
;
166 atomic_set(&rt
->dst
.__refcnt
, 1);
167 rt
->dst
.dev
= br
->dev
;
168 rt
->dst
.path
= &rt
->dst
;
169 dst_init_metrics(&rt
->dst
, br_dst_default_metrics
, true);
170 rt
->dst
.flags
= DST_NOXFRM
| DST_NOPEER
| DST_FAKE_RTABLE
;
171 rt
->dst
.ops
= &fake_dst_ops
;
174 static inline struct rtable
*bridge_parent_rtable(const struct net_device
*dev
)
176 struct net_bridge_port
*port
;
178 port
= br_port_get_rcu(dev
);
179 return port
? &port
->br
->fake_rtable
: NULL
;
182 static inline struct net_device
*bridge_parent(const struct net_device
*dev
)
184 struct net_bridge_port
*port
;
186 port
= br_port_get_rcu(dev
);
187 return port
? port
->br
->dev
: NULL
;
190 static inline struct nf_bridge_info
*nf_bridge_alloc(struct sk_buff
*skb
)
192 skb
->nf_bridge
= kzalloc(sizeof(struct nf_bridge_info
), GFP_ATOMIC
);
193 if (likely(skb
->nf_bridge
))
194 atomic_set(&(skb
->nf_bridge
->use
), 1);
196 return skb
->nf_bridge
;
199 static inline struct nf_bridge_info
*nf_bridge_unshare(struct sk_buff
*skb
)
201 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
203 if (atomic_read(&nf_bridge
->use
) > 1) {
204 struct nf_bridge_info
*tmp
= nf_bridge_alloc(skb
);
207 memcpy(tmp
, nf_bridge
, sizeof(struct nf_bridge_info
));
208 atomic_set(&tmp
->use
, 1);
210 nf_bridge_put(nf_bridge
);
216 static inline void nf_bridge_push_encap_header(struct sk_buff
*skb
)
218 unsigned int len
= nf_bridge_encap_header_len(skb
);
221 skb
->network_header
-= len
;
224 static inline void nf_bridge_pull_encap_header(struct sk_buff
*skb
)
226 unsigned int len
= nf_bridge_encap_header_len(skb
);
229 skb
->network_header
+= len
;
232 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff
*skb
)
234 unsigned int len
= nf_bridge_encap_header_len(skb
);
236 skb_pull_rcsum(skb
, len
);
237 skb
->network_header
+= len
;
240 static inline void nf_bridge_save_header(struct sk_buff
*skb
)
242 int header_size
= ETH_HLEN
+ nf_bridge_encap_header_len(skb
);
244 skb_copy_from_linear_data_offset(skb
, -header_size
,
245 skb
->nf_bridge
->data
, header_size
);
248 static inline void nf_bridge_update_protocol(struct sk_buff
*skb
)
250 if (skb
->nf_bridge
->mask
& BRNF_8021Q
)
251 skb
->protocol
= htons(ETH_P_8021Q
);
252 else if (skb
->nf_bridge
->mask
& BRNF_PPPoE
)
253 skb
->protocol
= htons(ETH_P_PPP_SES
);
256 /* When handing a packet over to the IP layer
257 * check whether we have a skb that is in the
261 static int br_parse_ip_options(struct sk_buff
*skb
)
263 struct ip_options
*opt
;
264 const struct iphdr
*iph
;
265 struct net_device
*dev
= skb
->dev
;
268 if (!pskb_may_pull(skb
, sizeof(struct iphdr
)))
272 opt
= &(IPCB(skb
)->opt
);
274 /* Basic sanity checks */
275 if (iph
->ihl
< 5 || iph
->version
!= 4)
278 if (!pskb_may_pull(skb
, iph
->ihl
*4))
282 if (unlikely(ip_fast_csum((u8
*)iph
, iph
->ihl
)))
285 len
= ntohs(iph
->tot_len
);
286 if (skb
->len
< len
) {
287 IP_INC_STATS_BH(dev_net(dev
), IPSTATS_MIB_INTRUNCATEDPKTS
);
289 } else if (len
< (iph
->ihl
*4))
292 if (pskb_trim_rcsum(skb
, len
)) {
293 IP_INC_STATS_BH(dev_net(dev
), IPSTATS_MIB_INDISCARDS
);
297 memset(IPCB(skb
), 0, sizeof(struct inet_skb_parm
));
301 opt
->optlen
= iph
->ihl
*4 - sizeof(struct iphdr
);
302 if (ip_options_compile(dev_net(dev
), opt
, skb
))
305 /* Check correct handling of SRR option */
306 if (unlikely(opt
->srr
)) {
307 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
308 if (in_dev
&& !IN_DEV_SOURCE_ROUTE(in_dev
))
311 if (ip_options_rcv_srr(skb
))
318 IP_INC_STATS_BH(dev_net(dev
), IPSTATS_MIB_INHDRERRORS
);
323 /* Fill in the header for fragmented IP packets handled by
324 * the IPv4 connection tracking code.
326 int nf_bridge_copy_header(struct sk_buff
*skb
)
329 unsigned int header_size
;
331 nf_bridge_update_protocol(skb
);
332 header_size
= ETH_HLEN
+ nf_bridge_encap_header_len(skb
);
333 err
= skb_cow_head(skb
, header_size
);
337 skb_copy_to_linear_data_offset(skb
, -header_size
,
338 skb
->nf_bridge
->data
, header_size
);
339 __skb_push(skb
, nf_bridge_encap_header_len(skb
));
343 /* PF_BRIDGE/PRE_ROUTING *********************************************/
344 /* Undo the changes made for ip6tables PREROUTING and continue the
345 * bridge PRE_ROUTING hook. */
346 static int br_nf_pre_routing_finish_ipv6(struct sk_buff
*skb
)
348 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
351 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
352 skb
->pkt_type
= PACKET_OTHERHOST
;
353 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
355 nf_bridge
->mask
^= BRNF_NF_BRIDGE_PREROUTING
;
357 rt
= bridge_parent_rtable(nf_bridge
->physindev
);
362 skb_dst_set_noref(skb
, &rt
->dst
);
364 skb
->dev
= nf_bridge
->physindev
;
365 nf_bridge_update_protocol(skb
);
366 nf_bridge_push_encap_header(skb
);
367 NF_HOOK_THRESH(NFPROTO_BRIDGE
, NF_BR_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
368 br_handle_frame_finish
, 1);
373 /* Obtain the correct destination MAC address, while preserving the original
374 * source MAC address. If we already know this address, we just copy it. If we
375 * don't, we use the neighbour framework to find out. In both cases, we make
376 * sure that br_handle_frame_finish() is called afterwards.
378 static int br_nf_pre_routing_finish_bridge(struct sk_buff
*skb
)
380 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
381 struct neighbour
*neigh
;
382 struct dst_entry
*dst
;
384 skb
->dev
= bridge_parent(skb
->dev
);
388 neigh
= dst_neigh_lookup_skb(dst
, skb
);
392 if (neigh
->hh
.hh_len
) {
393 neigh_hh_bridge(&neigh
->hh
, skb
);
394 skb
->dev
= nf_bridge
->physindev
;
395 ret
= br_handle_frame_finish(skb
);
397 /* the neighbour function below overwrites the complete
398 * MAC header, so we save the Ethernet source address and
401 skb_copy_from_linear_data_offset(skb
,
402 -(ETH_HLEN
-ETH_ALEN
),
403 skb
->nf_bridge
->data
,
405 /* tell br_dev_xmit to continue with forwarding */
406 nf_bridge
->mask
|= BRNF_BRIDGED_DNAT
;
407 ret
= neigh
->output(neigh
, skb
);
409 neigh_release(neigh
);
417 /* This requires some explaining. If DNAT has taken place,
418 * we will need to fix up the destination Ethernet address.
420 * There are two cases to consider:
421 * 1. The packet was DNAT'ed to a device in the same bridge
422 * port group as it was received on. We can still bridge
424 * 2. The packet was DNAT'ed to a different device, either
425 * a non-bridged device or another bridge port group.
426 * The packet will need to be routed.
428 * The correct way of distinguishing between these two cases is to
429 * call ip_route_input() and to look at skb->dst->dev, which is
430 * changed to the destination device if ip_route_input() succeeds.
432 * Let's first consider the case that ip_route_input() succeeds:
434 * If the output device equals the logical bridge device the packet
435 * came in on, we can consider this bridging. The corresponding MAC
436 * address will be obtained in br_nf_pre_routing_finish_bridge.
437 * Otherwise, the packet is considered to be routed and we just
438 * change the destination MAC address so that the packet will
439 * later be passed up to the IP stack to be routed. For a redirected
440 * packet, ip_route_input() will give back the localhost as output device,
441 * which differs from the bridge device.
443 * Let's now consider the case that ip_route_input() fails:
445 * This can be because the destination address is martian, in which case
446 * the packet will be dropped.
447 * If IP forwarding is disabled, ip_route_input() will fail, while
448 * ip_route_output_key() can return success. The source
449 * address for ip_route_output_key() is set to zero, so ip_route_output_key()
450 * thinks we're handling a locally generated packet and won't care
451 * if IP forwarding is enabled. If the output device equals the logical bridge
452 * device, we proceed as if ip_route_input() succeeded. If it differs from the
453 * logical bridge port or if ip_route_output_key() fails we drop the packet.
455 static int br_nf_pre_routing_finish(struct sk_buff
*skb
)
457 struct net_device
*dev
= skb
->dev
;
458 struct iphdr
*iph
= ip_hdr(skb
);
459 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
463 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
464 skb
->pkt_type
= PACKET_OTHERHOST
;
465 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
467 nf_bridge
->mask
^= BRNF_NF_BRIDGE_PREROUTING
;
468 if (dnat_took_place(skb
)) {
469 if ((err
= ip_route_input(skb
, iph
->daddr
, iph
->saddr
, iph
->tos
, dev
))) {
470 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
472 /* If err equals -EHOSTUNREACH the error is due to a
473 * martian destination or due to the fact that
474 * forwarding is disabled. For most martian packets,
475 * ip_route_output_key() will fail. It won't fail for 2 types of
476 * martian destinations: loopback destinations and destination
477 * 0.0.0.0. In both cases the packet will be dropped because the
478 * destination is the loopback device and not the bridge. */
479 if (err
!= -EHOSTUNREACH
|| !in_dev
|| IN_DEV_FORWARD(in_dev
))
482 rt
= ip_route_output(dev_net(dev
), iph
->daddr
, 0,
483 RT_TOS(iph
->tos
), 0);
485 /* - Bridged-and-DNAT'ed traffic doesn't
486 * require ip_forwarding. */
487 if (rt
->dst
.dev
== dev
) {
488 skb_dst_set(skb
, &rt
->dst
);
497 if (skb_dst(skb
)->dev
== dev
) {
499 skb
->dev
= nf_bridge
->physindev
;
500 nf_bridge_update_protocol(skb
);
501 nf_bridge_push_encap_header(skb
);
502 NF_HOOK_THRESH(NFPROTO_BRIDGE
,
505 br_nf_pre_routing_finish_bridge
,
509 memcpy(eth_hdr(skb
)->h_dest
, dev
->dev_addr
, ETH_ALEN
);
510 skb
->pkt_type
= PACKET_HOST
;
513 rt
= bridge_parent_rtable(nf_bridge
->physindev
);
518 skb_dst_set_noref(skb
, &rt
->dst
);
521 skb
->dev
= nf_bridge
->physindev
;
522 nf_bridge_update_protocol(skb
);
523 nf_bridge_push_encap_header(skb
);
524 NF_HOOK_THRESH(NFPROTO_BRIDGE
, NF_BR_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
525 br_handle_frame_finish
, 1);
530 static struct net_device
*brnf_get_logical_dev(struct sk_buff
*skb
, const struct net_device
*dev
)
532 struct net_device
*vlan
, *br
;
534 br
= bridge_parent(dev
);
535 if (brnf_pass_vlan_indev
== 0 || !vlan_tx_tag_present(skb
))
538 vlan
= __vlan_find_dev_deep(br
, skb
->vlan_proto
,
539 vlan_tx_tag_get(skb
) & VLAN_VID_MASK
);
541 return vlan
? vlan
: br
;
544 /* Some common code for IPv4/IPv6 */
545 static struct net_device
*setup_pre_routing(struct sk_buff
*skb
)
547 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
549 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
550 skb
->pkt_type
= PACKET_HOST
;
551 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
554 nf_bridge
->mask
|= BRNF_NF_BRIDGE_PREROUTING
;
555 nf_bridge
->physindev
= skb
->dev
;
556 skb
->dev
= brnf_get_logical_dev(skb
, skb
->dev
);
557 if (skb
->protocol
== htons(ETH_P_8021Q
))
558 nf_bridge
->mask
|= BRNF_8021Q
;
559 else if (skb
->protocol
== htons(ETH_P_PPP_SES
))
560 nf_bridge
->mask
|= BRNF_PPPoE
;
562 /* Must drop socket now because of tproxy. */
567 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
568 static int check_hbh_len(struct sk_buff
*skb
)
570 unsigned char *raw
= (u8
*)(ipv6_hdr(skb
) + 1);
572 const unsigned char *nh
= skb_network_header(skb
);
574 int len
= (raw
[1] + 1) << 3;
576 if ((raw
+ len
) - skb
->data
> skb_headlen(skb
))
583 int optlen
= nh
[off
+ 1] + 2;
594 if (nh
[off
+ 1] != 4 || (off
& 3) != 2)
596 pkt_len
= ntohl(*(__be32
*) (nh
+ off
+ 2));
597 if (pkt_len
<= IPV6_MAXPLEN
||
598 ipv6_hdr(skb
)->payload_len
)
600 if (pkt_len
> skb
->len
- sizeof(struct ipv6hdr
))
602 if (pskb_trim_rcsum(skb
,
603 pkt_len
+ sizeof(struct ipv6hdr
)))
605 nh
= skb_network_header(skb
);
622 /* Replicate the checks that IPv6 does on packet reception and pass the packet
623 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
624 static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops
*ops
,
626 const struct net_device
*in
,
627 const struct net_device
*out
,
628 int (*okfn
)(struct sk_buff
*))
630 const struct ipv6hdr
*hdr
;
633 if (skb
->len
< sizeof(struct ipv6hdr
))
636 if (!pskb_may_pull(skb
, sizeof(struct ipv6hdr
)))
641 if (hdr
->version
!= 6)
644 pkt_len
= ntohs(hdr
->payload_len
);
646 if (pkt_len
|| hdr
->nexthdr
!= NEXTHDR_HOP
) {
647 if (pkt_len
+ sizeof(struct ipv6hdr
) > skb
->len
)
649 if (pskb_trim_rcsum(skb
, pkt_len
+ sizeof(struct ipv6hdr
)))
652 if (hdr
->nexthdr
== NEXTHDR_HOP
&& check_hbh_len(skb
))
655 nf_bridge_put(skb
->nf_bridge
);
656 if (!nf_bridge_alloc(skb
))
658 if (!setup_pre_routing(skb
))
661 skb
->protocol
= htons(ETH_P_IPV6
);
662 NF_HOOK(NFPROTO_IPV6
, NF_INET_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
663 br_nf_pre_routing_finish_ipv6
);
668 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
669 * Replicate the checks that IPv4 does on packet reception.
670 * Set skb->dev to the bridge device (i.e. parent of the
671 * receiving device) to make netfilter happy, the REDIRECT
672 * target in particular. Save the original destination IP
673 * address to be able to detect DNAT afterwards. */
674 static unsigned int br_nf_pre_routing(const struct nf_hook_ops
*ops
,
676 const struct net_device
*in
,
677 const struct net_device
*out
,
678 int (*okfn
)(struct sk_buff
*))
680 struct net_bridge_port
*p
;
681 struct net_bridge
*br
;
682 __u32 len
= nf_bridge_encap_header_len(skb
);
684 if (unlikely(!pskb_may_pull(skb
, len
)))
687 p
= br_port_get_rcu(in
);
692 if (IS_IPV6(skb
) || IS_VLAN_IPV6(skb
) || IS_PPPOE_IPV6(skb
)) {
693 if (!brnf_call_ip6tables
&& !br
->nf_call_ip6tables
)
696 nf_bridge_pull_encap_header_rcsum(skb
);
697 return br_nf_pre_routing_ipv6(ops
, skb
, in
, out
, okfn
);
700 if (!brnf_call_iptables
&& !br
->nf_call_iptables
)
703 if (!IS_IP(skb
) && !IS_VLAN_IP(skb
) && !IS_PPPOE_IP(skb
))
706 nf_bridge_pull_encap_header_rcsum(skb
);
708 if (br_parse_ip_options(skb
))
711 nf_bridge_put(skb
->nf_bridge
);
712 if (!nf_bridge_alloc(skb
))
714 if (!setup_pre_routing(skb
))
716 store_orig_dstaddr(skb
);
717 skb
->protocol
= htons(ETH_P_IP
);
719 NF_HOOK(NFPROTO_IPV4
, NF_INET_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
720 br_nf_pre_routing_finish
);
726 /* PF_BRIDGE/LOCAL_IN ************************************************/
727 /* The packet is locally destined, which requires a real
728 * dst_entry, so detach the fake one. On the way up, the
729 * packet would pass through PRE_ROUTING again (which already
730 * took place when the packet entered the bridge), but we
731 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
732 * prevent this from happening. */
733 static unsigned int br_nf_local_in(const struct nf_hook_ops
*ops
,
735 const struct net_device
*in
,
736 const struct net_device
*out
,
737 int (*okfn
)(struct sk_buff
*))
739 br_drop_fake_rtable(skb
);
743 /* PF_BRIDGE/FORWARD *************************************************/
744 static int br_nf_forward_finish(struct sk_buff
*skb
)
746 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
747 struct net_device
*in
;
749 if (!IS_ARP(skb
) && !IS_VLAN_ARP(skb
)) {
750 in
= nf_bridge
->physindev
;
751 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
752 skb
->pkt_type
= PACKET_OTHERHOST
;
753 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
755 nf_bridge_update_protocol(skb
);
757 in
= *((struct net_device
**)(skb
->cb
));
759 nf_bridge_push_encap_header(skb
);
761 NF_HOOK_THRESH(NFPROTO_BRIDGE
, NF_BR_FORWARD
, skb
, in
,
762 skb
->dev
, br_forward_finish
, 1);
767 /* This is the 'purely bridged' case. For IP, we pass the packet to
768 * netfilter with indev and outdev set to the bridge device,
769 * but we are still able to filter on the 'real' indev/outdev
770 * because of the physdev module. For ARP, indev and outdev are the
772 static unsigned int br_nf_forward_ip(const struct nf_hook_ops
*ops
,
774 const struct net_device
*in
,
775 const struct net_device
*out
,
776 int (*okfn
)(struct sk_buff
*))
778 struct nf_bridge_info
*nf_bridge
;
779 struct net_device
*parent
;
785 /* Need exclusive nf_bridge_info since we might have multiple
786 * different physoutdevs. */
787 if (!nf_bridge_unshare(skb
))
790 parent
= bridge_parent(out
);
794 if (IS_IP(skb
) || IS_VLAN_IP(skb
) || IS_PPPOE_IP(skb
))
796 else if (IS_IPV6(skb
) || IS_VLAN_IPV6(skb
) || IS_PPPOE_IPV6(skb
))
801 nf_bridge_pull_encap_header(skb
);
803 nf_bridge
= skb
->nf_bridge
;
804 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
805 skb
->pkt_type
= PACKET_HOST
;
806 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
809 if (pf
== NFPROTO_IPV4
&& br_parse_ip_options(skb
))
812 /* The physdev module checks on this */
813 nf_bridge
->mask
|= BRNF_BRIDGED
;
814 nf_bridge
->physoutdev
= skb
->dev
;
815 if (pf
== NFPROTO_IPV4
)
816 skb
->protocol
= htons(ETH_P_IP
);
818 skb
->protocol
= htons(ETH_P_IPV6
);
820 NF_HOOK(pf
, NF_INET_FORWARD
, skb
, brnf_get_logical_dev(skb
, in
), parent
,
821 br_nf_forward_finish
);
826 static unsigned int br_nf_forward_arp(const struct nf_hook_ops
*ops
,
828 const struct net_device
*in
,
829 const struct net_device
*out
,
830 int (*okfn
)(struct sk_buff
*))
832 struct net_bridge_port
*p
;
833 struct net_bridge
*br
;
834 struct net_device
**d
= (struct net_device
**)(skb
->cb
);
836 p
= br_port_get_rcu(out
);
841 if (!brnf_call_arptables
&& !br
->nf_call_arptables
)
845 if (!IS_VLAN_ARP(skb
))
847 nf_bridge_pull_encap_header(skb
);
850 if (arp_hdr(skb
)->ar_pln
!= 4) {
851 if (IS_VLAN_ARP(skb
))
852 nf_bridge_push_encap_header(skb
);
855 *d
= (struct net_device
*)in
;
856 NF_HOOK(NFPROTO_ARP
, NF_ARP_FORWARD
, skb
, (struct net_device
*)in
,
857 (struct net_device
*)out
, br_nf_forward_finish
);
862 #if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV4)
863 static int br_nf_dev_queue_xmit(struct sk_buff
*skb
)
867 if (skb
->nfct
!= NULL
&& skb
->protocol
== htons(ETH_P_IP
) &&
868 skb
->len
+ nf_bridge_mtu_reduction(skb
) > skb
->dev
->mtu
&&
870 if (br_parse_ip_options(skb
))
871 /* Drop invalid packet */
873 ret
= ip_fragment(skb
, br_dev_queue_push_xmit
);
875 ret
= br_dev_queue_push_xmit(skb
);
880 static int br_nf_dev_queue_xmit(struct sk_buff
*skb
)
882 return br_dev_queue_push_xmit(skb
);
886 /* PF_BRIDGE/POST_ROUTING ********************************************/
887 static unsigned int br_nf_post_routing(const struct nf_hook_ops
*ops
,
889 const struct net_device
*in
,
890 const struct net_device
*out
,
891 int (*okfn
)(struct sk_buff
*))
893 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
894 struct net_device
*realoutdev
= bridge_parent(skb
->dev
);
897 if (!nf_bridge
|| !(nf_bridge
->mask
& BRNF_BRIDGED
))
903 if (IS_IP(skb
) || IS_VLAN_IP(skb
) || IS_PPPOE_IP(skb
))
905 else if (IS_IPV6(skb
) || IS_VLAN_IPV6(skb
) || IS_PPPOE_IPV6(skb
))
910 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
911 * about the value of skb->pkt_type. */
912 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
913 skb
->pkt_type
= PACKET_HOST
;
914 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
917 nf_bridge_pull_encap_header(skb
);
918 nf_bridge_save_header(skb
);
919 if (pf
== NFPROTO_IPV4
)
920 skb
->protocol
= htons(ETH_P_IP
);
922 skb
->protocol
= htons(ETH_P_IPV6
);
924 NF_HOOK(pf
, NF_INET_POST_ROUTING
, skb
, NULL
, realoutdev
,
925 br_nf_dev_queue_xmit
);
930 /* IP/SABOTAGE *****************************************************/
931 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
932 * for the second time. */
933 static unsigned int ip_sabotage_in(const struct nf_hook_ops
*ops
,
935 const struct net_device
*in
,
936 const struct net_device
*out
,
937 int (*okfn
)(struct sk_buff
*))
939 if (skb
->nf_bridge
&&
940 !(skb
->nf_bridge
->mask
& BRNF_NF_BRIDGE_PREROUTING
)) {
947 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
948 * br_dev_queue_push_xmit is called afterwards */
949 static struct nf_hook_ops br_nf_ops
[] __read_mostly
= {
951 .hook
= br_nf_pre_routing
,
952 .owner
= THIS_MODULE
,
953 .pf
= NFPROTO_BRIDGE
,
954 .hooknum
= NF_BR_PRE_ROUTING
,
955 .priority
= NF_BR_PRI_BRNF
,
958 .hook
= br_nf_local_in
,
959 .owner
= THIS_MODULE
,
960 .pf
= NFPROTO_BRIDGE
,
961 .hooknum
= NF_BR_LOCAL_IN
,
962 .priority
= NF_BR_PRI_BRNF
,
965 .hook
= br_nf_forward_ip
,
966 .owner
= THIS_MODULE
,
967 .pf
= NFPROTO_BRIDGE
,
968 .hooknum
= NF_BR_FORWARD
,
969 .priority
= NF_BR_PRI_BRNF
- 1,
972 .hook
= br_nf_forward_arp
,
973 .owner
= THIS_MODULE
,
974 .pf
= NFPROTO_BRIDGE
,
975 .hooknum
= NF_BR_FORWARD
,
976 .priority
= NF_BR_PRI_BRNF
,
979 .hook
= br_nf_post_routing
,
980 .owner
= THIS_MODULE
,
981 .pf
= NFPROTO_BRIDGE
,
982 .hooknum
= NF_BR_POST_ROUTING
,
983 .priority
= NF_BR_PRI_LAST
,
986 .hook
= ip_sabotage_in
,
987 .owner
= THIS_MODULE
,
989 .hooknum
= NF_INET_PRE_ROUTING
,
990 .priority
= NF_IP_PRI_FIRST
,
993 .hook
= ip_sabotage_in
,
994 .owner
= THIS_MODULE
,
996 .hooknum
= NF_INET_PRE_ROUTING
,
997 .priority
= NF_IP6_PRI_FIRST
,
1001 #ifdef CONFIG_SYSCTL
1003 int brnf_sysctl_call_tables(struct ctl_table
*ctl
, int write
,
1004 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1008 ret
= proc_dointvec(ctl
, write
, buffer
, lenp
, ppos
);
1010 if (write
&& *(int *)(ctl
->data
))
1011 *(int *)(ctl
->data
) = 1;
1015 static struct ctl_table brnf_table
[] = {
1017 .procname
= "bridge-nf-call-arptables",
1018 .data
= &brnf_call_arptables
,
1019 .maxlen
= sizeof(int),
1021 .proc_handler
= brnf_sysctl_call_tables
,
1024 .procname
= "bridge-nf-call-iptables",
1025 .data
= &brnf_call_iptables
,
1026 .maxlen
= sizeof(int),
1028 .proc_handler
= brnf_sysctl_call_tables
,
1031 .procname
= "bridge-nf-call-ip6tables",
1032 .data
= &brnf_call_ip6tables
,
1033 .maxlen
= sizeof(int),
1035 .proc_handler
= brnf_sysctl_call_tables
,
1038 .procname
= "bridge-nf-filter-vlan-tagged",
1039 .data
= &brnf_filter_vlan_tagged
,
1040 .maxlen
= sizeof(int),
1042 .proc_handler
= brnf_sysctl_call_tables
,
1045 .procname
= "bridge-nf-filter-pppoe-tagged",
1046 .data
= &brnf_filter_pppoe_tagged
,
1047 .maxlen
= sizeof(int),
1049 .proc_handler
= brnf_sysctl_call_tables
,
1052 .procname
= "bridge-nf-pass-vlan-input-dev",
1053 .data
= &brnf_pass_vlan_indev
,
1054 .maxlen
= sizeof(int),
1056 .proc_handler
= brnf_sysctl_call_tables
,
1062 int __init
br_netfilter_init(void)
1066 ret
= dst_entries_init(&fake_dst_ops
);
1070 ret
= nf_register_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
1072 dst_entries_destroy(&fake_dst_ops
);
1075 #ifdef CONFIG_SYSCTL
1076 brnf_sysctl_header
= register_net_sysctl(&init_net
, "net/bridge", brnf_table
);
1077 if (brnf_sysctl_header
== NULL
) {
1079 "br_netfilter: can't register to sysctl.\n");
1080 nf_unregister_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
1081 dst_entries_destroy(&fake_dst_ops
);
1085 printk(KERN_NOTICE
"Bridge firewalling registered\n");
1089 void br_netfilter_fini(void)
1091 nf_unregister_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
1092 #ifdef CONFIG_SYSCTL
1093 unregister_net_sysctl_table(brnf_sysctl_header
);
1095 dst_entries_destroy(&fake_dst_ops
);