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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Forwarding decision
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13
Herbert Xu025d89c2010-02-27 19:41:43 +000014#include <linux/err.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090015#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/kernel.h>
17#include <linux/netdevice.h>
WANG Congc06ee962010-05-06 00:48:24 -070018#include <linux/netpoll.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/skbuff.h>
Stephen Hemminger85ca7192006-04-26 02:39:19 -070020#include <linux/if_vlan.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/netfilter_bridge.h>
22#include "br_private.h"
23
David S. Miller87faf3c2010-03-16 14:37:47 -070024static int deliver_clone(const struct net_bridge_port *prev,
25 struct sk_buff *skb,
Michael Braun7f7708f2010-03-16 00:26:22 -070026 void (*__packet_hook)(const struct net_bridge_port *p,
27 struct sk_buff *skb));
28
tanxiaojun1a81a2e2013-12-16 21:32:46 +080029/* Don't forward packets to originating port or forwarding disabled */
YOSHIFUJI Hideaki9d6f2292007-02-09 23:24:35 +090030static inline int should_deliver(const struct net_bridge_port *p,
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 const struct sk_buff *skb)
32{
Nikolay Aleksandrov2594e902015-09-25 19:00:11 +020033 struct net_bridge_vlan_group *vg;
34
Nikolay Aleksandrov907b1e62015-10-12 21:47:02 +020035 vg = nbp_vlan_group_rcu(p);
tanxiaojuna97bfc12013-12-19 13:28:11 +080036 return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
Nikolay Aleksandrov2594e902015-09-25 19:00:11 +020037 br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING;
Linus Torvalds1da177e2005-04-16 15:20:36 -070038}
39
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -050040int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041{
Toshiaki Makitadf356d52015-07-28 19:05:37 +090042 if (!is_skb_forwardable(skb->dev, skb))
43 goto drop;
44
45 skb_push(skb, ETH_HLEN);
46 br_drop_fake_rtable(skb);
Toshiaki Makitadf356d52015-07-28 19:05:37 +090047
48 if (skb->ip_summed == CHECKSUM_PARTIAL &&
49 (skb->protocol == htons(ETH_P_8021Q) ||
50 skb->protocol == htons(ETH_P_8021AD))) {
51 int depth;
52
53 if (!__vlan_get_protocol(skb, skb->protocol, &depth))
54 goto drop;
55
56 skb_set_network_header(skb, depth);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 }
58
Toshiaki Makitadf356d52015-07-28 19:05:37 +090059 dev_queue_xmit(skb);
60
61 return 0;
62
63drop:
64 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 return 0;
66}
Pablo Neira Ayuso34666d42014-09-18 11:29:03 +020067EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -050069int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070070{
Eric W. Biederman29a26a52015-09-15 20:04:16 -050071 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING,
72 net, sk, skb, NULL, skb->dev,
Stephen Hemminger9ef513b2006-05-25 15:58:54 -070073 br_dev_queue_push_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Linus Torvalds1da177e2005-04-16 15:20:36 -070075}
Pablo Neira Ayuso34666d42014-09-18 11:29:03 +020076EXPORT_SYMBOL_GPL(br_forward_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
79{
Nikolay Aleksandrov2594e902015-09-25 19:00:11 +020080 struct net_bridge_vlan_group *vg;
81
Nikolay Aleksandrov907b1e62015-10-12 21:47:02 +020082 vg = nbp_vlan_group_rcu(to);
Nikolay Aleksandrov2594e902015-09-25 19:00:11 +020083 skb = br_handle_vlan(to->br, vg, skb);
Vlad Yasevich78851982013-02-13 12:00:14 +000084 if (!skb)
85 return;
86
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 skb->dev = to->dev;
Herbert Xu91d2c342010-06-10 16:12:50 +000088
Amerigo Wange15c3c222012-08-10 01:24:45 +000089 if (unlikely(netpoll_tx_running(to->br->dev))) {
Vlad Yasevichf6367b42014-03-27 17:32:30 -040090 if (!is_skb_forwardable(skb->dev, skb))
Herbert Xu91d2c342010-06-10 16:12:50 +000091 kfree_skb(skb);
92 else {
93 skb_push(skb, ETH_HLEN);
94 br_netpoll_send_skb(to, skb);
95 }
96 return;
97 }
98
Eric W. Biederman29a26a52015-09-15 20:04:16 -050099 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT,
100 dev_net(skb->dev), NULL, skb,NULL, skb->dev,
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100101 br_forward_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102}
103
104static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
105{
Nikolay Aleksandrov2594e902015-09-25 19:00:11 +0200106 struct net_bridge_vlan_group *vg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 struct net_device *indev;
108
Herbert Xu4906f992009-02-09 15:07:18 -0800109 if (skb_warn_if_lro(skb)) {
110 kfree_skb(skb);
111 return;
112 }
113
Nikolay Aleksandrov907b1e62015-10-12 21:47:02 +0200114 vg = nbp_vlan_group_rcu(to);
Nikolay Aleksandrov2594e902015-09-25 19:00:11 +0200115 skb = br_handle_vlan(to->br, vg, skb);
Vlad Yasevich78851982013-02-13 12:00:14 +0000116 if (!skb)
117 return;
118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 indev = skb->dev;
120 skb->dev = to->dev;
Herbert Xu35fc92a2007-03-26 23:22:20 -0700121 skb_forward_csum(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Eric W. Biederman29a26a52015-09-15 20:04:16 -0500123 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD,
124 dev_net(indev), NULL, skb, indev, skb->dev,
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100125 br_forward_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126}
127
128/* called with rcu_read_lock */
129void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
130{
stephen hemminger43598812011-12-08 07:17:49 +0000131 if (to && should_deliver(to, skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 __br_deliver(to, skb);
133 return;
134 }
135
136 kfree_skb(skb);
137}
Pablo Neira Ayuso523b9292014-10-25 18:40:26 +0200138EXPORT_SYMBOL_GPL(br_deliver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140/* called with rcu_read_lock */
Michael Braun7f7708f2010-03-16 00:26:22 -0700141void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
Roopa Prabhub7af1472015-10-27 07:52:56 -0700143 if (to && should_deliver(to, skb)) {
Michael Braun7f7708f2010-03-16 00:26:22 -0700144 if (skb0)
145 deliver_clone(to, skb, __br_forward);
146 else
147 __br_forward(to, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 return;
149 }
150
Michael Braun7f7708f2010-03-16 00:26:22 -0700151 if (!skb0)
152 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153}
154
David S. Miller87faf3c2010-03-16 14:37:47 -0700155static int deliver_clone(const struct net_bridge_port *prev,
156 struct sk_buff *skb,
Herbert Xu025d89c2010-02-27 19:41:43 +0000157 void (*__packet_hook)(const struct net_bridge_port *p,
158 struct sk_buff *skb))
159{
Herbert Xufed396a2010-06-15 21:43:07 -0700160 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
161
Herbert Xu025d89c2010-02-27 19:41:43 +0000162 skb = skb_clone(skb, GFP_ATOMIC);
163 if (!skb) {
Herbert Xu025d89c2010-02-27 19:41:43 +0000164 dev->stats.tx_dropped++;
165 return -ENOMEM;
166 }
167
168 __packet_hook(prev, skb);
169 return 0;
170}
171
172static struct net_bridge_port *maybe_deliver(
173 struct net_bridge_port *prev, struct net_bridge_port *p,
174 struct sk_buff *skb,
175 void (*__packet_hook)(const struct net_bridge_port *p,
176 struct sk_buff *skb))
177{
178 int err;
179
180 if (!should_deliver(p, skb))
181 return prev;
182
183 if (!prev)
184 goto out;
185
186 err = deliver_clone(prev, skb, __packet_hook);
187 if (err)
188 return ERR_PTR(err);
189
190out:
191 return p;
192}
193
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194/* called under bridge lock */
Herbert Xue081e1e2007-09-16 16:20:48 -0700195static void br_flood(struct net_bridge *br, struct sk_buff *skb,
Herbert Xub33084b2010-02-27 19:41:41 +0000196 struct sk_buff *skb0,
197 void (*__packet_hook)(const struct net_bridge_port *p,
Vlad Yasevich867a5942013-06-05 10:08:01 -0400198 struct sk_buff *skb),
199 bool unicast)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200{
201 struct net_bridge_port *p;
202 struct net_bridge_port *prev;
203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 prev = NULL;
205
206 list_for_each_entry_rcu(p, &br->port_list, list) {
Vlad Yasevich867a5942013-06-05 10:08:01 -0400207 /* Do not flood unicast traffic to ports that turn it off */
208 if (unicast && !(p->flags & BR_FLOOD))
209 continue;
Kyeyoon Park95850112014-10-23 14:49:17 -0700210
211 /* Do not flood to ports that enable proxy ARP */
212 if (p->flags & BR_PROXYARP)
213 continue;
Jouni Malinen842a9ae2015-03-04 12:54:21 +0200214 if ((p->flags & BR_PROXYARP_WIFI) &&
215 BR_INPUT_SKB_CB(skb)->proxyarp_replied)
216 continue;
Kyeyoon Park95850112014-10-23 14:49:17 -0700217
Herbert Xu025d89c2010-02-27 19:41:43 +0000218 prev = maybe_deliver(prev, p, skb, __packet_hook);
219 if (IS_ERR(prev))
220 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 }
222
Herbert Xub33084b2010-02-27 19:41:41 +0000223 if (!prev)
224 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
Herbert Xu025d89c2010-02-27 19:41:43 +0000226 if (skb0)
227 deliver_clone(prev, skb, __packet_hook);
228 else
229 __packet_hook(prev, skb);
Herbert Xub33084b2010-02-27 19:41:41 +0000230 return;
231
232out:
233 if (!skb0)
234 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235}
236
237
238/* called with rcu_read_lock */
Vlad Yasevich867a5942013-06-05 10:08:01 -0400239void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Vlad Yasevich867a5942013-06-05 10:08:01 -0400241 br_flood(br, skb, NULL, __br_deliver, unicast);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243
244/* called under bridge lock */
Herbert Xub33084b2010-02-27 19:41:41 +0000245void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
Vlad Yasevich867a5942013-06-05 10:08:01 -0400246 struct sk_buff *skb2, bool unicast)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247{
Vlad Yasevich867a5942013-06-05 10:08:01 -0400248 br_flood(br, skb, skb2, __br_forward, unicast);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249}
Herbert Xu5cb5e942010-02-27 19:41:46 +0000250
251#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
252/* called with rcu_read_lock */
253static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
254 struct sk_buff *skb, struct sk_buff *skb0,
255 void (*__packet_hook)(
256 const struct net_bridge_port *p,
257 struct sk_buff *skb))
258{
259 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
260 struct net_bridge *br = netdev_priv(dev);
stephen hemmingerafe01592010-04-27 15:01:07 +0000261 struct net_bridge_port *prev = NULL;
Herbert Xu5cb5e942010-02-27 19:41:46 +0000262 struct net_bridge_port_group *p;
263 struct hlist_node *rp;
264
Eric Dumazete8051682010-11-15 06:38:10 +0000265 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
stephen hemminger83f6a742010-04-27 15:01:06 +0000266 p = mdst ? rcu_dereference(mdst->ports) : NULL;
Herbert Xu5cb5e942010-02-27 19:41:46 +0000267 while (p || rp) {
stephen hemmingerafe01592010-04-27 15:01:07 +0000268 struct net_bridge_port *port, *lport, *rport;
269
Herbert Xu5cb5e942010-02-27 19:41:46 +0000270 lport = p ? p->port : NULL;
271 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
272 NULL;
273
274 port = (unsigned long)lport > (unsigned long)rport ?
275 lport : rport;
276
277 prev = maybe_deliver(prev, port, skb, __packet_hook);
278 if (IS_ERR(prev))
279 goto out;
280
281 if ((unsigned long)lport >= (unsigned long)port)
stephen hemminger83f6a742010-04-27 15:01:06 +0000282 p = rcu_dereference(p->next);
Herbert Xu5cb5e942010-02-27 19:41:46 +0000283 if ((unsigned long)rport >= (unsigned long)port)
Eric Dumazete8051682010-11-15 06:38:10 +0000284 rp = rcu_dereference(hlist_next_rcu(rp));
Herbert Xu5cb5e942010-02-27 19:41:46 +0000285 }
286
287 if (!prev)
288 goto out;
289
290 if (skb0)
291 deliver_clone(prev, skb, __packet_hook);
292 else
293 __packet_hook(prev, skb);
294 return;
295
296out:
297 if (!skb0)
298 kfree_skb(skb);
299}
300
301/* called with rcu_read_lock */
302void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
303 struct sk_buff *skb)
304{
305 br_multicast_flood(mdst, skb, NULL, __br_deliver);
306}
307
308/* called with rcu_read_lock */
309void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
310 struct sk_buff *skb, struct sk_buff *skb2)
311{
312 br_multicast_flood(mdst, skb, skb2, __br_forward);
313}
314#endif