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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{
tanxiaojuna97bfc12013-12-19 13:28:11 +080033 return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
Vlad Yasevich85f46c62013-02-13 12:00:11 +000034 br_allowed_egress(p->br, nbp_get_vlan_info(p), skb) &&
tanxiaojuna97bfc12013-12-19 13:28:11 +080035 p->state == BR_STATE_FORWARDING;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036}
37
38int br_dev_queue_push_xmit(struct sk_buff *skb)
39{
Changli Gaof88de8d2010-12-25 03:41:30 +000040 /* ip_fragment doesn't copy the MAC header */
41 if (nf_bridge_maybe_copy_header(skb) ||
Vlad Yasevichf6367b42014-03-27 17:32:30 -040042 !is_skb_forwardable(skb->dev, skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 kfree_skb(skb);
Changli Gaof88de8d2010-12-25 03:41:30 +000044 } else {
45 skb_push(skb, ETH_HLEN);
Peter Huang (Peng)a881e962012-04-19 20:12:51 +000046 br_drop_fake_rtable(skb);
Changli Gaof88de8d2010-12-25 03:41:30 +000047 dev_queue_xmit(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 }
49
50 return 0;
51}
Pablo Neira Ayuso34666d42014-09-18 11:29:03 +020052EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54int br_forward_finish(struct sk_buff *skb)
55{
Jan Engelhardt713aefa2010-03-23 04:07:21 +010056 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
Stephen Hemminger9ef513b2006-05-25 15:58:54 -070057 br_dev_queue_push_xmit);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Linus Torvalds1da177e2005-04-16 15:20:36 -070059}
Pablo Neira Ayuso34666d42014-09-18 11:29:03 +020060EXPORT_SYMBOL_GPL(br_forward_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
63{
Vlad Yasevich78851982013-02-13 12:00:14 +000064 skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
65 if (!skb)
66 return;
67
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 skb->dev = to->dev;
Herbert Xu91d2c342010-06-10 16:12:50 +000069
Amerigo Wange15c3c222012-08-10 01:24:45 +000070 if (unlikely(netpoll_tx_running(to->br->dev))) {
Vlad Yasevichf6367b42014-03-27 17:32:30 -040071 if (!is_skb_forwardable(skb->dev, skb))
Herbert Xu91d2c342010-06-10 16:12:50 +000072 kfree_skb(skb);
73 else {
74 skb_push(skb, ETH_HLEN);
75 br_netpoll_send_skb(to, skb);
76 }
77 return;
78 }
79
Jan Engelhardt713aefa2010-03-23 04:07:21 +010080 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
81 br_forward_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082}
83
84static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
85{
86 struct net_device *indev;
87
Herbert Xu4906f992009-02-09 15:07:18 -080088 if (skb_warn_if_lro(skb)) {
89 kfree_skb(skb);
90 return;
91 }
92
Vlad Yasevich78851982013-02-13 12:00:14 +000093 skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb);
94 if (!skb)
95 return;
96
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 indev = skb->dev;
98 skb->dev = to->dev;
Herbert Xu35fc92a2007-03-26 23:22:20 -070099 skb_forward_csum(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100101 NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
102 br_forward_finish);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103}
104
105/* called with rcu_read_lock */
106void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
107{
stephen hemminger43598812011-12-08 07:17:49 +0000108 if (to && should_deliver(to, skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 __br_deliver(to, skb);
110 return;
111 }
112
113 kfree_skb(skb);
114}
Pablo Neira Ayuso523b9292014-10-25 18:40:26 +0200115EXPORT_SYMBOL_GPL(br_deliver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
117/* called with rcu_read_lock */
Michael Braun7f7708f2010-03-16 00:26:22 -0700118void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
Herbert Xu4906f992009-02-09 15:07:18 -0800120 if (should_deliver(to, skb)) {
Michael Braun7f7708f2010-03-16 00:26:22 -0700121 if (skb0)
122 deliver_clone(to, skb, __br_forward);
123 else
124 __br_forward(to, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 return;
126 }
127
Michael Braun7f7708f2010-03-16 00:26:22 -0700128 if (!skb0)
129 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130}
131
David S. Miller87faf3c2010-03-16 14:37:47 -0700132static int deliver_clone(const struct net_bridge_port *prev,
133 struct sk_buff *skb,
Herbert Xu025d89c2010-02-27 19:41:43 +0000134 void (*__packet_hook)(const struct net_bridge_port *p,
135 struct sk_buff *skb))
136{
Herbert Xufed396a2010-06-15 21:43:07 -0700137 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
138
Herbert Xu025d89c2010-02-27 19:41:43 +0000139 skb = skb_clone(skb, GFP_ATOMIC);
140 if (!skb) {
Herbert Xu025d89c2010-02-27 19:41:43 +0000141 dev->stats.tx_dropped++;
142 return -ENOMEM;
143 }
144
145 __packet_hook(prev, skb);
146 return 0;
147}
148
149static struct net_bridge_port *maybe_deliver(
150 struct net_bridge_port *prev, struct net_bridge_port *p,
151 struct sk_buff *skb,
152 void (*__packet_hook)(const struct net_bridge_port *p,
153 struct sk_buff *skb))
154{
155 int err;
156
157 if (!should_deliver(p, skb))
158 return prev;
159
160 if (!prev)
161 goto out;
162
163 err = deliver_clone(prev, skb, __packet_hook);
164 if (err)
165 return ERR_PTR(err);
166
167out:
168 return p;
169}
170
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171/* called under bridge lock */
Herbert Xue081e1e2007-09-16 16:20:48 -0700172static void br_flood(struct net_bridge *br, struct sk_buff *skb,
Herbert Xub33084b2010-02-27 19:41:41 +0000173 struct sk_buff *skb0,
174 void (*__packet_hook)(const struct net_bridge_port *p,
Vlad Yasevich867a5942013-06-05 10:08:01 -0400175 struct sk_buff *skb),
176 bool unicast)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177{
178 struct net_bridge_port *p;
179 struct net_bridge_port *prev;
180
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 prev = NULL;
182
183 list_for_each_entry_rcu(p, &br->port_list, list) {
Vlad Yasevich867a5942013-06-05 10:08:01 -0400184 /* Do not flood unicast traffic to ports that turn it off */
185 if (unicast && !(p->flags & BR_FLOOD))
186 continue;
Herbert Xu025d89c2010-02-27 19:41:43 +0000187 prev = maybe_deliver(prev, p, skb, __packet_hook);
188 if (IS_ERR(prev))
189 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 }
191
Herbert Xub33084b2010-02-27 19:41:41 +0000192 if (!prev)
193 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Herbert Xu025d89c2010-02-27 19:41:43 +0000195 if (skb0)
196 deliver_clone(prev, skb, __packet_hook);
197 else
198 __packet_hook(prev, skb);
Herbert Xub33084b2010-02-27 19:41:41 +0000199 return;
200
201out:
202 if (!skb0)
203 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204}
205
206
207/* called with rcu_read_lock */
Vlad Yasevich867a5942013-06-05 10:08:01 -0400208void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209{
Vlad Yasevich867a5942013-06-05 10:08:01 -0400210 br_flood(br, skb, NULL, __br_deliver, unicast);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211}
212
213/* called under bridge lock */
Herbert Xub33084b2010-02-27 19:41:41 +0000214void br_flood_forward(struct net_bridge *br, struct sk_buff *skb,
Vlad Yasevich867a5942013-06-05 10:08:01 -0400215 struct sk_buff *skb2, bool unicast)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216{
Vlad Yasevich867a5942013-06-05 10:08:01 -0400217 br_flood(br, skb, skb2, __br_forward, unicast);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218}
Herbert Xu5cb5e942010-02-27 19:41:46 +0000219
220#ifdef CONFIG_BRIDGE_IGMP_SNOOPING
221/* called with rcu_read_lock */
222static void br_multicast_flood(struct net_bridge_mdb_entry *mdst,
223 struct sk_buff *skb, struct sk_buff *skb0,
224 void (*__packet_hook)(
225 const struct net_bridge_port *p,
226 struct sk_buff *skb))
227{
228 struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev;
229 struct net_bridge *br = netdev_priv(dev);
stephen hemmingerafe01592010-04-27 15:01:07 +0000230 struct net_bridge_port *prev = NULL;
Herbert Xu5cb5e942010-02-27 19:41:46 +0000231 struct net_bridge_port_group *p;
232 struct hlist_node *rp;
233
Eric Dumazete8051682010-11-15 06:38:10 +0000234 rp = rcu_dereference(hlist_first_rcu(&br->router_list));
stephen hemminger83f6a742010-04-27 15:01:06 +0000235 p = mdst ? rcu_dereference(mdst->ports) : NULL;
Herbert Xu5cb5e942010-02-27 19:41:46 +0000236 while (p || rp) {
stephen hemmingerafe01592010-04-27 15:01:07 +0000237 struct net_bridge_port *port, *lport, *rport;
238
Herbert Xu5cb5e942010-02-27 19:41:46 +0000239 lport = p ? p->port : NULL;
240 rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) :
241 NULL;
242
243 port = (unsigned long)lport > (unsigned long)rport ?
244 lport : rport;
245
246 prev = maybe_deliver(prev, port, skb, __packet_hook);
247 if (IS_ERR(prev))
248 goto out;
249
250 if ((unsigned long)lport >= (unsigned long)port)
stephen hemminger83f6a742010-04-27 15:01:06 +0000251 p = rcu_dereference(p->next);
Herbert Xu5cb5e942010-02-27 19:41:46 +0000252 if ((unsigned long)rport >= (unsigned long)port)
Eric Dumazete8051682010-11-15 06:38:10 +0000253 rp = rcu_dereference(hlist_next_rcu(rp));
Herbert Xu5cb5e942010-02-27 19:41:46 +0000254 }
255
256 if (!prev)
257 goto out;
258
259 if (skb0)
260 deliver_clone(prev, skb, __packet_hook);
261 else
262 __packet_hook(prev, skb);
263 return;
264
265out:
266 if (!skb0)
267 kfree_skb(skb);
268}
269
270/* called with rcu_read_lock */
271void br_multicast_deliver(struct net_bridge_mdb_entry *mdst,
272 struct sk_buff *skb)
273{
274 br_multicast_flood(mdst, skb, NULL, __br_deliver);
275}
276
277/* called with rcu_read_lock */
278void br_multicast_forward(struct net_bridge_mdb_entry *mdst,
279 struct sk_buff *skb, struct sk_buff *skb2)
280{
281 br_multicast_flood(mdst, skb, skb2, __br_forward);
282}
283#endif