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
, u32 mtu
)
118 static u32
*fake_cow_metrics(struct dst_entry
*dst
, unsigned long old
)
123 static struct neighbour
*fake_neigh_lookup(const struct dst_entry
*dst
, const void *daddr
)
128 static unsigned int fake_mtu(const struct dst_entry
*dst
)
130 return dst
->dev
->mtu
;
133 static struct dst_ops fake_dst_ops
= {
135 .protocol
= cpu_to_be16(ETH_P_IP
),
136 .update_pmtu
= fake_update_pmtu
,
137 .cow_metrics
= fake_cow_metrics
,
138 .neigh_lookup
= fake_neigh_lookup
,
143 * Initialize bogus route table used to keep netfilter happy.
144 * Currently, we fill in the PMTU entry because netfilter
145 * refragmentation needs it, and the rt_flags entry because
146 * ipt_REJECT needs it. Future netfilter modules might
147 * require us to fill additional fields.
149 static const u32 br_dst_default_metrics
[RTAX_MAX
] = {
150 [RTAX_MTU
- 1] = 1500,
153 void br_netfilter_rtable_init(struct net_bridge
*br
)
155 struct rtable
*rt
= &br
->fake_rtable
;
157 atomic_set(&rt
->dst
.__refcnt
, 1);
158 rt
->dst
.dev
= br
->dev
;
159 rt
->dst
.path
= &rt
->dst
;
160 dst_init_metrics(&rt
->dst
, br_dst_default_metrics
, true);
161 rt
->dst
.flags
= DST_NOXFRM
| DST_NOPEER
| DST_FAKE_RTABLE
;
162 rt
->dst
.ops
= &fake_dst_ops
;
165 static inline struct rtable
*bridge_parent_rtable(const struct net_device
*dev
)
167 struct net_bridge_port
*port
;
169 port
= br_port_get_rcu(dev
);
170 return port
? &port
->br
->fake_rtable
: NULL
;
173 static inline struct net_device
*bridge_parent(const struct net_device
*dev
)
175 struct net_bridge_port
*port
;
177 port
= br_port_get_rcu(dev
);
178 return port
? port
->br
->dev
: NULL
;
181 static inline struct nf_bridge_info
*nf_bridge_alloc(struct sk_buff
*skb
)
183 skb
->nf_bridge
= kzalloc(sizeof(struct nf_bridge_info
), GFP_ATOMIC
);
184 if (likely(skb
->nf_bridge
))
185 atomic_set(&(skb
->nf_bridge
->use
), 1);
187 return skb
->nf_bridge
;
190 static inline struct nf_bridge_info
*nf_bridge_unshare(struct sk_buff
*skb
)
192 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
194 if (atomic_read(&nf_bridge
->use
) > 1) {
195 struct nf_bridge_info
*tmp
= nf_bridge_alloc(skb
);
198 memcpy(tmp
, nf_bridge
, sizeof(struct nf_bridge_info
));
199 atomic_set(&tmp
->use
, 1);
201 nf_bridge_put(nf_bridge
);
207 static inline void nf_bridge_push_encap_header(struct sk_buff
*skb
)
209 unsigned int len
= nf_bridge_encap_header_len(skb
);
212 skb
->network_header
-= len
;
215 static inline void nf_bridge_pull_encap_header(struct sk_buff
*skb
)
217 unsigned int len
= nf_bridge_encap_header_len(skb
);
220 skb
->network_header
+= len
;
223 static inline void nf_bridge_pull_encap_header_rcsum(struct sk_buff
*skb
)
225 unsigned int len
= nf_bridge_encap_header_len(skb
);
227 skb_pull_rcsum(skb
, len
);
228 skb
->network_header
+= len
;
231 static inline void nf_bridge_save_header(struct sk_buff
*skb
)
233 int header_size
= ETH_HLEN
+ nf_bridge_encap_header_len(skb
);
235 skb_copy_from_linear_data_offset(skb
, -header_size
,
236 skb
->nf_bridge
->data
, header_size
);
239 static inline void nf_bridge_update_protocol(struct sk_buff
*skb
)
241 if (skb
->nf_bridge
->mask
& BRNF_8021Q
)
242 skb
->protocol
= htons(ETH_P_8021Q
);
243 else if (skb
->nf_bridge
->mask
& BRNF_PPPoE
)
244 skb
->protocol
= htons(ETH_P_PPP_SES
);
247 /* When handing a packet over to the IP layer
248 * check whether we have a skb that is in the
252 static int br_parse_ip_options(struct sk_buff
*skb
)
254 struct ip_options
*opt
;
255 const struct iphdr
*iph
;
256 struct net_device
*dev
= skb
->dev
;
260 opt
= &(IPCB(skb
)->opt
);
262 /* Basic sanity checks */
263 if (iph
->ihl
< 5 || iph
->version
!= 4)
266 if (!pskb_may_pull(skb
, iph
->ihl
*4))
270 if (unlikely(ip_fast_csum((u8
*)iph
, iph
->ihl
)))
273 len
= ntohs(iph
->tot_len
);
274 if (skb
->len
< len
) {
275 IP_INC_STATS_BH(dev_net(dev
), IPSTATS_MIB_INTRUNCATEDPKTS
);
277 } else if (len
< (iph
->ihl
*4))
280 if (pskb_trim_rcsum(skb
, len
)) {
281 IP_INC_STATS_BH(dev_net(dev
), IPSTATS_MIB_INDISCARDS
);
285 memset(IPCB(skb
), 0, sizeof(struct inet_skb_parm
));
289 opt
->optlen
= iph
->ihl
*4 - sizeof(struct iphdr
);
290 if (ip_options_compile(dev_net(dev
), opt
, skb
))
293 /* Check correct handling of SRR option */
294 if (unlikely(opt
->srr
)) {
295 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
296 if (in_dev
&& !IN_DEV_SOURCE_ROUTE(in_dev
))
299 if (ip_options_rcv_srr(skb
))
306 IP_INC_STATS_BH(dev_net(dev
), IPSTATS_MIB_INHDRERRORS
);
311 /* Fill in the header for fragmented IP packets handled by
312 * the IPv4 connection tracking code.
314 int nf_bridge_copy_header(struct sk_buff
*skb
)
317 unsigned int header_size
;
319 nf_bridge_update_protocol(skb
);
320 header_size
= ETH_HLEN
+ nf_bridge_encap_header_len(skb
);
321 err
= skb_cow_head(skb
, header_size
);
325 skb_copy_to_linear_data_offset(skb
, -header_size
,
326 skb
->nf_bridge
->data
, header_size
);
327 __skb_push(skb
, nf_bridge_encap_header_len(skb
));
331 /* PF_BRIDGE/PRE_ROUTING *********************************************/
332 /* Undo the changes made for ip6tables PREROUTING and continue the
333 * bridge PRE_ROUTING hook. */
334 static int br_nf_pre_routing_finish_ipv6(struct sk_buff
*skb
)
336 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
339 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
340 skb
->pkt_type
= PACKET_OTHERHOST
;
341 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
343 nf_bridge
->mask
^= BRNF_NF_BRIDGE_PREROUTING
;
345 rt
= bridge_parent_rtable(nf_bridge
->physindev
);
350 skb_dst_set_noref(skb
, &rt
->dst
);
352 skb
->dev
= nf_bridge
->physindev
;
353 nf_bridge_update_protocol(skb
);
354 nf_bridge_push_encap_header(skb
);
355 NF_HOOK_THRESH(NFPROTO_BRIDGE
, NF_BR_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
356 br_handle_frame_finish
, 1);
361 /* Obtain the correct destination MAC address, while preserving the original
362 * source MAC address. If we already know this address, we just copy it. If we
363 * don't, we use the neighbour framework to find out. In both cases, we make
364 * sure that br_handle_frame_finish() is called afterwards.
366 static int br_nf_pre_routing_finish_bridge(struct sk_buff
*skb
)
368 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
369 struct neighbour
*neigh
;
370 struct dst_entry
*dst
;
372 skb
->dev
= bridge_parent(skb
->dev
);
376 neigh
= dst_get_neighbour_noref(dst
);
377 if (neigh
->hh
.hh_len
) {
378 neigh_hh_bridge(&neigh
->hh
, skb
);
379 skb
->dev
= nf_bridge
->physindev
;
380 return br_handle_frame_finish(skb
);
382 /* the neighbour function below overwrites the complete
383 * MAC header, so we save the Ethernet source address and
384 * protocol number. */
385 skb_copy_from_linear_data_offset(skb
, -(ETH_HLEN
-ETH_ALEN
), skb
->nf_bridge
->data
, ETH_HLEN
-ETH_ALEN
);
386 /* tell br_dev_xmit to continue with forwarding */
387 nf_bridge
->mask
|= BRNF_BRIDGED_DNAT
;
388 return neigh
->output(neigh
, skb
);
395 /* This requires some explaining. If DNAT has taken place,
396 * we will need to fix up the destination Ethernet address.
398 * There are two cases to consider:
399 * 1. The packet was DNAT'ed to a device in the same bridge
400 * port group as it was received on. We can still bridge
402 * 2. The packet was DNAT'ed to a different device, either
403 * a non-bridged device or another bridge port group.
404 * The packet will need to be routed.
406 * The correct way of distinguishing between these two cases is to
407 * call ip_route_input() and to look at skb->dst->dev, which is
408 * changed to the destination device if ip_route_input() succeeds.
410 * Let's first consider the case that ip_route_input() succeeds:
412 * If the output device equals the logical bridge device the packet
413 * came in on, we can consider this bridging. The corresponding MAC
414 * address will be obtained in br_nf_pre_routing_finish_bridge.
415 * Otherwise, the packet is considered to be routed and we just
416 * change the destination MAC address so that the packet will
417 * later be passed up to the IP stack to be routed. For a redirected
418 * packet, ip_route_input() will give back the localhost as output device,
419 * which differs from the bridge device.
421 * Let's now consider the case that ip_route_input() fails:
423 * This can be because the destination address is martian, in which case
424 * the packet will be dropped.
425 * If IP forwarding is disabled, ip_route_input() will fail, while
426 * ip_route_output_key() can return success. The source
427 * address for ip_route_output_key() is set to zero, so ip_route_output_key()
428 * thinks we're handling a locally generated packet and won't care
429 * if IP forwarding is enabled. If the output device equals the logical bridge
430 * device, we proceed as if ip_route_input() succeeded. If it differs from the
431 * logical bridge port or if ip_route_output_key() fails we drop the packet.
433 static int br_nf_pre_routing_finish(struct sk_buff
*skb
)
435 struct net_device
*dev
= skb
->dev
;
436 struct iphdr
*iph
= ip_hdr(skb
);
437 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
441 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
442 skb
->pkt_type
= PACKET_OTHERHOST
;
443 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
445 nf_bridge
->mask
^= BRNF_NF_BRIDGE_PREROUTING
;
446 if (dnat_took_place(skb
)) {
447 if ((err
= ip_route_input(skb
, iph
->daddr
, iph
->saddr
, iph
->tos
, dev
))) {
448 struct in_device
*in_dev
= __in_dev_get_rcu(dev
);
450 /* If err equals -EHOSTUNREACH the error is due to a
451 * martian destination or due to the fact that
452 * forwarding is disabled. For most martian packets,
453 * ip_route_output_key() will fail. It won't fail for 2 types of
454 * martian destinations: loopback destinations and destination
455 * 0.0.0.0. In both cases the packet will be dropped because the
456 * destination is the loopback device and not the bridge. */
457 if (err
!= -EHOSTUNREACH
|| !in_dev
|| IN_DEV_FORWARD(in_dev
))
460 rt
= ip_route_output(dev_net(dev
), iph
->daddr
, 0,
461 RT_TOS(iph
->tos
), 0);
463 /* - Bridged-and-DNAT'ed traffic doesn't
464 * require ip_forwarding. */
465 if (rt
->dst
.dev
== dev
) {
466 skb_dst_set(skb
, &rt
->dst
);
475 if (skb_dst(skb
)->dev
== dev
) {
477 skb
->dev
= nf_bridge
->physindev
;
478 nf_bridge_update_protocol(skb
);
479 nf_bridge_push_encap_header(skb
);
480 NF_HOOK_THRESH(NFPROTO_BRIDGE
,
483 br_nf_pre_routing_finish_bridge
,
487 memcpy(eth_hdr(skb
)->h_dest
, dev
->dev_addr
, ETH_ALEN
);
488 skb
->pkt_type
= PACKET_HOST
;
491 rt
= bridge_parent_rtable(nf_bridge
->physindev
);
496 skb_dst_set_noref(skb
, &rt
->dst
);
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
, NF_BR_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
503 br_handle_frame_finish
, 1);
508 static struct net_device
*brnf_get_logical_dev(struct sk_buff
*skb
, const struct net_device
*dev
)
510 struct net_device
*vlan
, *br
;
512 br
= bridge_parent(dev
);
513 if (brnf_pass_vlan_indev
== 0 || !vlan_tx_tag_present(skb
))
516 vlan
= __vlan_find_dev_deep(br
, vlan_tx_tag_get(skb
) & VLAN_VID_MASK
);
518 return vlan
? vlan
: br
;
521 /* Some common code for IPv4/IPv6 */
522 static struct net_device
*setup_pre_routing(struct sk_buff
*skb
)
524 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
526 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
527 skb
->pkt_type
= PACKET_HOST
;
528 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
531 nf_bridge
->mask
|= BRNF_NF_BRIDGE_PREROUTING
;
532 nf_bridge
->physindev
= skb
->dev
;
533 skb
->dev
= brnf_get_logical_dev(skb
, skb
->dev
);
534 if (skb
->protocol
== htons(ETH_P_8021Q
))
535 nf_bridge
->mask
|= BRNF_8021Q
;
536 else if (skb
->protocol
== htons(ETH_P_PPP_SES
))
537 nf_bridge
->mask
|= BRNF_PPPoE
;
542 /* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */
543 static int check_hbh_len(struct sk_buff
*skb
)
545 unsigned char *raw
= (u8
*)(ipv6_hdr(skb
) + 1);
547 const unsigned char *nh
= skb_network_header(skb
);
549 int len
= (raw
[1] + 1) << 3;
551 if ((raw
+ len
) - skb
->data
> skb_headlen(skb
))
558 int optlen
= nh
[off
+ 1] + 2;
569 if (nh
[off
+ 1] != 4 || (off
& 3) != 2)
571 pkt_len
= ntohl(*(__be32
*) (nh
+ off
+ 2));
572 if (pkt_len
<= IPV6_MAXPLEN
||
573 ipv6_hdr(skb
)->payload_len
)
575 if (pkt_len
> skb
->len
- sizeof(struct ipv6hdr
))
577 if (pskb_trim_rcsum(skb
,
578 pkt_len
+ sizeof(struct ipv6hdr
)))
580 nh
= skb_network_header(skb
);
597 /* Replicate the checks that IPv6 does on packet reception and pass the packet
598 * to ip6tables, which doesn't support NAT, so things are fairly simple. */
599 static unsigned int br_nf_pre_routing_ipv6(unsigned int hook
,
601 const struct net_device
*in
,
602 const struct net_device
*out
,
603 int (*okfn
)(struct sk_buff
*))
605 const struct ipv6hdr
*hdr
;
608 if (skb
->len
< sizeof(struct ipv6hdr
))
611 if (!pskb_may_pull(skb
, sizeof(struct ipv6hdr
)))
616 if (hdr
->version
!= 6)
619 pkt_len
= ntohs(hdr
->payload_len
);
621 if (pkt_len
|| hdr
->nexthdr
!= NEXTHDR_HOP
) {
622 if (pkt_len
+ sizeof(struct ipv6hdr
) > skb
->len
)
624 if (pskb_trim_rcsum(skb
, pkt_len
+ sizeof(struct ipv6hdr
)))
627 if (hdr
->nexthdr
== NEXTHDR_HOP
&& check_hbh_len(skb
))
630 nf_bridge_put(skb
->nf_bridge
);
631 if (!nf_bridge_alloc(skb
))
633 if (!setup_pre_routing(skb
))
636 skb
->protocol
= htons(ETH_P_IPV6
);
637 NF_HOOK(NFPROTO_IPV6
, NF_INET_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
638 br_nf_pre_routing_finish_ipv6
);
643 /* Direct IPv6 traffic to br_nf_pre_routing_ipv6.
644 * Replicate the checks that IPv4 does on packet reception.
645 * Set skb->dev to the bridge device (i.e. parent of the
646 * receiving device) to make netfilter happy, the REDIRECT
647 * target in particular. Save the original destination IP
648 * address to be able to detect DNAT afterwards. */
649 static unsigned int br_nf_pre_routing(unsigned int hook
, struct sk_buff
*skb
,
650 const struct net_device
*in
,
651 const struct net_device
*out
,
652 int (*okfn
)(struct sk_buff
*))
654 struct net_bridge_port
*p
;
655 struct net_bridge
*br
;
656 __u32 len
= nf_bridge_encap_header_len(skb
);
658 if (unlikely(!pskb_may_pull(skb
, len
)))
661 p
= br_port_get_rcu(in
);
666 if (IS_IPV6(skb
) || IS_VLAN_IPV6(skb
) || IS_PPPOE_IPV6(skb
)) {
667 if (!brnf_call_ip6tables
&& !br
->nf_call_ip6tables
)
670 nf_bridge_pull_encap_header_rcsum(skb
);
671 return br_nf_pre_routing_ipv6(hook
, skb
, in
, out
, okfn
);
674 if (!brnf_call_iptables
&& !br
->nf_call_iptables
)
677 if (!IS_IP(skb
) && !IS_VLAN_IP(skb
) && !IS_PPPOE_IP(skb
))
680 nf_bridge_pull_encap_header_rcsum(skb
);
682 if (br_parse_ip_options(skb
))
685 nf_bridge_put(skb
->nf_bridge
);
686 if (!nf_bridge_alloc(skb
))
688 if (!setup_pre_routing(skb
))
690 store_orig_dstaddr(skb
);
691 skb
->protocol
= htons(ETH_P_IP
);
693 NF_HOOK(NFPROTO_IPV4
, NF_INET_PRE_ROUTING
, skb
, skb
->dev
, NULL
,
694 br_nf_pre_routing_finish
);
700 /* PF_BRIDGE/LOCAL_IN ************************************************/
701 /* The packet is locally destined, which requires a real
702 * dst_entry, so detach the fake one. On the way up, the
703 * packet would pass through PRE_ROUTING again (which already
704 * took place when the packet entered the bridge), but we
705 * register an IPv4 PRE_ROUTING 'sabotage' hook that will
706 * prevent this from happening. */
707 static unsigned int br_nf_local_in(unsigned int hook
, struct sk_buff
*skb
,
708 const struct net_device
*in
,
709 const struct net_device
*out
,
710 int (*okfn
)(struct sk_buff
*))
712 br_drop_fake_rtable(skb
);
716 /* PF_BRIDGE/FORWARD *************************************************/
717 static int br_nf_forward_finish(struct sk_buff
*skb
)
719 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
720 struct net_device
*in
;
722 if (!IS_ARP(skb
) && !IS_VLAN_ARP(skb
)) {
723 in
= nf_bridge
->physindev
;
724 if (nf_bridge
->mask
& BRNF_PKT_TYPE
) {
725 skb
->pkt_type
= PACKET_OTHERHOST
;
726 nf_bridge
->mask
^= BRNF_PKT_TYPE
;
728 nf_bridge_update_protocol(skb
);
730 in
= *((struct net_device
**)(skb
->cb
));
732 nf_bridge_push_encap_header(skb
);
734 NF_HOOK_THRESH(NFPROTO_BRIDGE
, NF_BR_FORWARD
, skb
, in
,
735 skb
->dev
, br_forward_finish
, 1);
740 /* This is the 'purely bridged' case. For IP, we pass the packet to
741 * netfilter with indev and outdev set to the bridge device,
742 * but we are still able to filter on the 'real' indev/outdev
743 * because of the physdev module. For ARP, indev and outdev are the
745 static unsigned int br_nf_forward_ip(unsigned int hook
, struct sk_buff
*skb
,
746 const struct net_device
*in
,
747 const struct net_device
*out
,
748 int (*okfn
)(struct sk_buff
*))
750 struct nf_bridge_info
*nf_bridge
;
751 struct net_device
*parent
;
757 /* Need exclusive nf_bridge_info since we might have multiple
758 * different physoutdevs. */
759 if (!nf_bridge_unshare(skb
))
762 parent
= bridge_parent(out
);
766 if (IS_IP(skb
) || IS_VLAN_IP(skb
) || IS_PPPOE_IP(skb
))
768 else if (IS_IPV6(skb
) || IS_VLAN_IPV6(skb
) || IS_PPPOE_IPV6(skb
))
773 nf_bridge_pull_encap_header(skb
);
775 nf_bridge
= skb
->nf_bridge
;
776 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
777 skb
->pkt_type
= PACKET_HOST
;
778 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
781 if (pf
== PF_INET
&& br_parse_ip_options(skb
))
784 /* The physdev module checks on this */
785 nf_bridge
->mask
|= BRNF_BRIDGED
;
786 nf_bridge
->physoutdev
= skb
->dev
;
788 skb
->protocol
= htons(ETH_P_IP
);
790 skb
->protocol
= htons(ETH_P_IPV6
);
792 NF_HOOK(pf
, NF_INET_FORWARD
, skb
, brnf_get_logical_dev(skb
, in
), parent
,
793 br_nf_forward_finish
);
798 static unsigned int br_nf_forward_arp(unsigned int hook
, struct sk_buff
*skb
,
799 const struct net_device
*in
,
800 const struct net_device
*out
,
801 int (*okfn
)(struct sk_buff
*))
803 struct net_bridge_port
*p
;
804 struct net_bridge
*br
;
805 struct net_device
**d
= (struct net_device
**)(skb
->cb
);
807 p
= br_port_get_rcu(out
);
812 if (!brnf_call_arptables
&& !br
->nf_call_arptables
)
816 if (!IS_VLAN_ARP(skb
))
818 nf_bridge_pull_encap_header(skb
);
821 if (arp_hdr(skb
)->ar_pln
!= 4) {
822 if (IS_VLAN_ARP(skb
))
823 nf_bridge_push_encap_header(skb
);
826 *d
= (struct net_device
*)in
;
827 NF_HOOK(NFPROTO_ARP
, NF_ARP_FORWARD
, skb
, (struct net_device
*)in
,
828 (struct net_device
*)out
, br_nf_forward_finish
);
833 #if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV4)
834 static int br_nf_dev_queue_xmit(struct sk_buff
*skb
)
838 if (skb
->nfct
!= NULL
&& skb
->protocol
== htons(ETH_P_IP
) &&
839 skb
->len
+ nf_bridge_mtu_reduction(skb
) > skb
->dev
->mtu
&&
841 if (br_parse_ip_options(skb
))
842 /* Drop invalid packet */
844 ret
= ip_fragment(skb
, br_dev_queue_push_xmit
);
846 ret
= br_dev_queue_push_xmit(skb
);
851 static int br_nf_dev_queue_xmit(struct sk_buff
*skb
)
853 return br_dev_queue_push_xmit(skb
);
857 /* PF_BRIDGE/POST_ROUTING ********************************************/
858 static unsigned int br_nf_post_routing(unsigned int hook
, struct sk_buff
*skb
,
859 const struct net_device
*in
,
860 const struct net_device
*out
,
861 int (*okfn
)(struct sk_buff
*))
863 struct nf_bridge_info
*nf_bridge
= skb
->nf_bridge
;
864 struct net_device
*realoutdev
= bridge_parent(skb
->dev
);
867 if (!nf_bridge
|| !(nf_bridge
->mask
& BRNF_BRIDGED
))
873 if (IS_IP(skb
) || IS_VLAN_IP(skb
) || IS_PPPOE_IP(skb
))
875 else if (IS_IPV6(skb
) || IS_VLAN_IPV6(skb
) || IS_PPPOE_IPV6(skb
))
880 /* We assume any code from br_dev_queue_push_xmit onwards doesn't care
881 * about the value of skb->pkt_type. */
882 if (skb
->pkt_type
== PACKET_OTHERHOST
) {
883 skb
->pkt_type
= PACKET_HOST
;
884 nf_bridge
->mask
|= BRNF_PKT_TYPE
;
887 nf_bridge_pull_encap_header(skb
);
888 nf_bridge_save_header(skb
);
890 skb
->protocol
= htons(ETH_P_IP
);
892 skb
->protocol
= htons(ETH_P_IPV6
);
894 NF_HOOK(pf
, NF_INET_POST_ROUTING
, skb
, NULL
, realoutdev
,
895 br_nf_dev_queue_xmit
);
900 /* IP/SABOTAGE *****************************************************/
901 /* Don't hand locally destined packets to PF_INET(6)/PRE_ROUTING
902 * for the second time. */
903 static unsigned int ip_sabotage_in(unsigned int hook
, struct sk_buff
*skb
,
904 const struct net_device
*in
,
905 const struct net_device
*out
,
906 int (*okfn
)(struct sk_buff
*))
908 if (skb
->nf_bridge
&&
909 !(skb
->nf_bridge
->mask
& BRNF_NF_BRIDGE_PREROUTING
)) {
916 /* For br_nf_post_routing, we need (prio = NF_BR_PRI_LAST), because
917 * br_dev_queue_push_xmit is called afterwards */
918 static struct nf_hook_ops br_nf_ops
[] __read_mostly
= {
920 .hook
= br_nf_pre_routing
,
921 .owner
= THIS_MODULE
,
923 .hooknum
= NF_BR_PRE_ROUTING
,
924 .priority
= NF_BR_PRI_BRNF
,
927 .hook
= br_nf_local_in
,
928 .owner
= THIS_MODULE
,
930 .hooknum
= NF_BR_LOCAL_IN
,
931 .priority
= NF_BR_PRI_BRNF
,
934 .hook
= br_nf_forward_ip
,
935 .owner
= THIS_MODULE
,
937 .hooknum
= NF_BR_FORWARD
,
938 .priority
= NF_BR_PRI_BRNF
- 1,
941 .hook
= br_nf_forward_arp
,
942 .owner
= THIS_MODULE
,
944 .hooknum
= NF_BR_FORWARD
,
945 .priority
= NF_BR_PRI_BRNF
,
948 .hook
= br_nf_post_routing
,
949 .owner
= THIS_MODULE
,
951 .hooknum
= NF_BR_POST_ROUTING
,
952 .priority
= NF_BR_PRI_LAST
,
955 .hook
= ip_sabotage_in
,
956 .owner
= THIS_MODULE
,
958 .hooknum
= NF_INET_PRE_ROUTING
,
959 .priority
= NF_IP_PRI_FIRST
,
962 .hook
= ip_sabotage_in
,
963 .owner
= THIS_MODULE
,
965 .hooknum
= NF_INET_PRE_ROUTING
,
966 .priority
= NF_IP6_PRI_FIRST
,
972 int brnf_sysctl_call_tables(ctl_table
* ctl
, int write
,
973 void __user
* buffer
, size_t * lenp
, loff_t
* ppos
)
977 ret
= proc_dointvec(ctl
, write
, buffer
, lenp
, ppos
);
979 if (write
&& *(int *)(ctl
->data
))
980 *(int *)(ctl
->data
) = 1;
984 static ctl_table brnf_table
[] = {
986 .procname
= "bridge-nf-call-arptables",
987 .data
= &brnf_call_arptables
,
988 .maxlen
= sizeof(int),
990 .proc_handler
= brnf_sysctl_call_tables
,
993 .procname
= "bridge-nf-call-iptables",
994 .data
= &brnf_call_iptables
,
995 .maxlen
= sizeof(int),
997 .proc_handler
= brnf_sysctl_call_tables
,
1000 .procname
= "bridge-nf-call-ip6tables",
1001 .data
= &brnf_call_ip6tables
,
1002 .maxlen
= sizeof(int),
1004 .proc_handler
= brnf_sysctl_call_tables
,
1007 .procname
= "bridge-nf-filter-vlan-tagged",
1008 .data
= &brnf_filter_vlan_tagged
,
1009 .maxlen
= sizeof(int),
1011 .proc_handler
= brnf_sysctl_call_tables
,
1014 .procname
= "bridge-nf-filter-pppoe-tagged",
1015 .data
= &brnf_filter_pppoe_tagged
,
1016 .maxlen
= sizeof(int),
1018 .proc_handler
= brnf_sysctl_call_tables
,
1021 .procname
= "bridge-nf-pass-vlan-input-dev",
1022 .data
= &brnf_pass_vlan_indev
,
1023 .maxlen
= sizeof(int),
1025 .proc_handler
= brnf_sysctl_call_tables
,
1031 int __init
br_netfilter_init(void)
1035 ret
= dst_entries_init(&fake_dst_ops
);
1039 ret
= nf_register_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
1041 dst_entries_destroy(&fake_dst_ops
);
1044 #ifdef CONFIG_SYSCTL
1045 brnf_sysctl_header
= register_net_sysctl(&init_net
, "net/bridge", brnf_table
);
1046 if (brnf_sysctl_header
== NULL
) {
1048 "br_netfilter: can't register to sysctl.\n");
1049 nf_unregister_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
1050 dst_entries_destroy(&fake_dst_ops
);
1054 printk(KERN_NOTICE
"Bridge firewalling registered\n");
1058 void br_netfilter_fini(void)
1060 nf_unregister_hooks(br_nf_ops
, ARRAY_SIZE(br_nf_ops
));
1061 #ifdef CONFIG_SYSCTL
1062 unregister_net_sysctl_table(brnf_sysctl_header
);
1064 dst_entries_destroy(&fake_dst_ops
);