Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Forwarding decision | |
3 | * Linux ethernet bridge | |
4 | * | |
5 | * Authors: | |
6 | * Lennert Buytenhek <buytenh@gnu.org> | |
7 | * | |
1da177e4 LT |
8 | * 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 | ||
025d89c2 | 14 | #include <linux/err.h> |
5a0e3ad6 | 15 | #include <linux/slab.h> |
1da177e4 LT |
16 | #include <linux/kernel.h> |
17 | #include <linux/netdevice.h> | |
c06ee961 | 18 | #include <linux/netpoll.h> |
1da177e4 | 19 | #include <linux/skbuff.h> |
85ca719e | 20 | #include <linux/if_vlan.h> |
1da177e4 LT |
21 | #include <linux/netfilter_bridge.h> |
22 | #include "br_private.h" | |
23 | ||
87faf3cc DM |
24 | static int deliver_clone(const struct net_bridge_port *prev, |
25 | struct sk_buff *skb, | |
7f7708f0 MB |
26 | void (*__packet_hook)(const struct net_bridge_port *p, |
27 | struct sk_buff *skb)); | |
28 | ||
1a81a2e0 | 29 | /* Don't forward packets to originating port or forwarding disabled */ |
9d6f229f | 30 | static inline int should_deliver(const struct net_bridge_port *p, |
1da177e4 LT |
31 | const struct sk_buff *skb) |
32 | { | |
a97bfc1d | 33 | return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && |
85f46c6b | 34 | br_allowed_egress(p->br, nbp_get_vlan_info(p), skb) && |
a97bfc1d | 35 | p->state == BR_STATE_FORWARDING; |
1da177e4 LT |
36 | } |
37 | ||
7026b1dd | 38 | int br_dev_queue_push_xmit(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 39 | { |
df356d5e TM |
40 | if (!is_skb_forwardable(skb->dev, skb)) |
41 | goto drop; | |
42 | ||
43 | skb_push(skb, ETH_HLEN); | |
44 | br_drop_fake_rtable(skb); | |
45 | skb_sender_cpu_clear(skb); | |
46 | ||
47 | if (skb->ip_summed == CHECKSUM_PARTIAL && | |
48 | (skb->protocol == htons(ETH_P_8021Q) || | |
49 | skb->protocol == htons(ETH_P_8021AD))) { | |
50 | int depth; | |
51 | ||
52 | if (!__vlan_get_protocol(skb, skb->protocol, &depth)) | |
53 | goto drop; | |
54 | ||
55 | skb_set_network_header(skb, depth); | |
1da177e4 LT |
56 | } |
57 | ||
df356d5e TM |
58 | dev_queue_xmit(skb); |
59 | ||
60 | return 0; | |
61 | ||
62 | drop: | |
63 | kfree_skb(skb); | |
1da177e4 LT |
64 | return 0; |
65 | } | |
34666d46 | 66 | EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit); |
1da177e4 | 67 | |
7026b1dd | 68 | int br_forward_finish(struct sock *sk, struct sk_buff *skb) |
1da177e4 | 69 | { |
29a26a56 EB |
70 | struct net *net = dev_net(skb->dev); |
71 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, | |
72 | net, sk, skb, NULL, skb->dev, | |
9ef513be | 73 | br_dev_queue_push_xmit); |
1da177e4 | 74 | |
1da177e4 | 75 | } |
34666d46 | 76 | EXPORT_SYMBOL_GPL(br_forward_finish); |
1da177e4 LT |
77 | |
78 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
79 | { | |
78851988 VY |
80 | skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb); |
81 | if (!skb) | |
82 | return; | |
83 | ||
1da177e4 | 84 | skb->dev = to->dev; |
91d2c34a | 85 | |
e15c3c22 | 86 | if (unlikely(netpoll_tx_running(to->br->dev))) { |
f6367b46 | 87 | if (!is_skb_forwardable(skb->dev, skb)) |
91d2c34a HX |
88 | kfree_skb(skb); |
89 | else { | |
90 | skb_push(skb, ETH_HLEN); | |
91 | br_netpoll_send_skb(to, skb); | |
92 | } | |
93 | return; | |
94 | } | |
95 | ||
29a26a56 EB |
96 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, |
97 | dev_net(skb->dev), NULL, skb,NULL, skb->dev, | |
713aefa3 | 98 | br_forward_finish); |
1da177e4 LT |
99 | } |
100 | ||
101 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
102 | { | |
103 | struct net_device *indev; | |
104 | ||
4906f998 HX |
105 | if (skb_warn_if_lro(skb)) { |
106 | kfree_skb(skb); | |
107 | return; | |
108 | } | |
109 | ||
78851988 VY |
110 | skb = br_handle_vlan(to->br, nbp_get_vlan_info(to), skb); |
111 | if (!skb) | |
112 | return; | |
113 | ||
1da177e4 LT |
114 | indev = skb->dev; |
115 | skb->dev = to->dev; | |
35fc92a9 | 116 | skb_forward_csum(skb); |
1da177e4 | 117 | |
29a26a56 EB |
118 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, |
119 | dev_net(indev), NULL, skb, indev, skb->dev, | |
713aefa3 | 120 | br_forward_finish); |
1da177e4 LT |
121 | } |
122 | ||
123 | /* called with rcu_read_lock */ | |
124 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
125 | { | |
43598813 | 126 | if (to && should_deliver(to, skb)) { |
1da177e4 LT |
127 | __br_deliver(to, skb); |
128 | return; | |
129 | } | |
130 | ||
131 | kfree_skb(skb); | |
132 | } | |
523b929d | 133 | EXPORT_SYMBOL_GPL(br_deliver); |
1da177e4 LT |
134 | |
135 | /* called with rcu_read_lock */ | |
7f7708f0 | 136 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0) |
1da177e4 | 137 | { |
4906f998 | 138 | if (should_deliver(to, skb)) { |
7f7708f0 MB |
139 | if (skb0) |
140 | deliver_clone(to, skb, __br_forward); | |
141 | else | |
142 | __br_forward(to, skb); | |
1da177e4 LT |
143 | return; |
144 | } | |
145 | ||
7f7708f0 MB |
146 | if (!skb0) |
147 | kfree_skb(skb); | |
1da177e4 LT |
148 | } |
149 | ||
87faf3cc DM |
150 | static int deliver_clone(const struct net_bridge_port *prev, |
151 | struct sk_buff *skb, | |
025d89c2 HX |
152 | void (*__packet_hook)(const struct net_bridge_port *p, |
153 | struct sk_buff *skb)) | |
154 | { | |
fed396a5 HX |
155 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
156 | ||
025d89c2 HX |
157 | skb = skb_clone(skb, GFP_ATOMIC); |
158 | if (!skb) { | |
025d89c2 HX |
159 | dev->stats.tx_dropped++; |
160 | return -ENOMEM; | |
161 | } | |
162 | ||
163 | __packet_hook(prev, skb); | |
164 | return 0; | |
165 | } | |
166 | ||
167 | static struct net_bridge_port *maybe_deliver( | |
168 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
169 | struct sk_buff *skb, | |
170 | void (*__packet_hook)(const struct net_bridge_port *p, | |
171 | struct sk_buff *skb)) | |
172 | { | |
173 | int err; | |
174 | ||
175 | if (!should_deliver(p, skb)) | |
176 | return prev; | |
177 | ||
178 | if (!prev) | |
179 | goto out; | |
180 | ||
181 | err = deliver_clone(prev, skb, __packet_hook); | |
182 | if (err) | |
183 | return ERR_PTR(err); | |
184 | ||
185 | out: | |
186 | return p; | |
187 | } | |
188 | ||
1da177e4 | 189 | /* called under bridge lock */ |
e081e1e3 | 190 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
b33084be HX |
191 | struct sk_buff *skb0, |
192 | void (*__packet_hook)(const struct net_bridge_port *p, | |
867a5943 VY |
193 | struct sk_buff *skb), |
194 | bool unicast) | |
1da177e4 LT |
195 | { |
196 | struct net_bridge_port *p; | |
197 | struct net_bridge_port *prev; | |
198 | ||
1da177e4 LT |
199 | prev = NULL; |
200 | ||
201 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
867a5943 VY |
202 | /* Do not flood unicast traffic to ports that turn it off */ |
203 | if (unicast && !(p->flags & BR_FLOOD)) | |
204 | continue; | |
95850116 KP |
205 | |
206 | /* Do not flood to ports that enable proxy ARP */ | |
207 | if (p->flags & BR_PROXYARP) | |
208 | continue; | |
842a9ae0 JM |
209 | if ((p->flags & BR_PROXYARP_WIFI) && |
210 | BR_INPUT_SKB_CB(skb)->proxyarp_replied) | |
211 | continue; | |
95850116 | 212 | |
025d89c2 HX |
213 | prev = maybe_deliver(prev, p, skb, __packet_hook); |
214 | if (IS_ERR(prev)) | |
215 | goto out; | |
1da177e4 LT |
216 | } |
217 | ||
b33084be HX |
218 | if (!prev) |
219 | goto out; | |
220 | ||
025d89c2 HX |
221 | if (skb0) |
222 | deliver_clone(prev, skb, __packet_hook); | |
223 | else | |
224 | __packet_hook(prev, skb); | |
b33084be | 225 | return; |
1da177e4 | 226 | |
b33084be HX |
227 | out: |
228 | if (!skb0) | |
229 | kfree_skb(skb); | |
1da177e4 LT |
230 | } |
231 | ||
232 | ||
233 | /* called with rcu_read_lock */ | |
867a5943 | 234 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast) |
1da177e4 | 235 | { |
867a5943 | 236 | br_flood(br, skb, NULL, __br_deliver, unicast); |
1da177e4 LT |
237 | } |
238 | ||
239 | /* called under bridge lock */ | |
b33084be | 240 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, |
867a5943 | 241 | struct sk_buff *skb2, bool unicast) |
1da177e4 | 242 | { |
867a5943 | 243 | br_flood(br, skb, skb2, __br_forward, unicast); |
1da177e4 | 244 | } |
5cb5e947 HX |
245 | |
246 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING | |
247 | /* called with rcu_read_lock */ | |
248 | static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, | |
249 | struct sk_buff *skb, struct sk_buff *skb0, | |
250 | void (*__packet_hook)( | |
251 | const struct net_bridge_port *p, | |
252 | struct sk_buff *skb)) | |
253 | { | |
254 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
255 | struct net_bridge *br = netdev_priv(dev); | |
afe0159d | 256 | struct net_bridge_port *prev = NULL; |
5cb5e947 HX |
257 | struct net_bridge_port_group *p; |
258 | struct hlist_node *rp; | |
259 | ||
e8051688 | 260 | rp = rcu_dereference(hlist_first_rcu(&br->router_list)); |
83f6a740 | 261 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 | 262 | while (p || rp) { |
afe0159d | 263 | struct net_bridge_port *port, *lport, *rport; |
264 | ||
5cb5e947 HX |
265 | lport = p ? p->port : NULL; |
266 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
267 | NULL; | |
268 | ||
269 | port = (unsigned long)lport > (unsigned long)rport ? | |
270 | lport : rport; | |
271 | ||
272 | prev = maybe_deliver(prev, port, skb, __packet_hook); | |
273 | if (IS_ERR(prev)) | |
274 | goto out; | |
275 | ||
276 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 277 | p = rcu_dereference(p->next); |
5cb5e947 | 278 | if ((unsigned long)rport >= (unsigned long)port) |
e8051688 | 279 | rp = rcu_dereference(hlist_next_rcu(rp)); |
5cb5e947 HX |
280 | } |
281 | ||
282 | if (!prev) | |
283 | goto out; | |
284 | ||
285 | if (skb0) | |
286 | deliver_clone(prev, skb, __packet_hook); | |
287 | else | |
288 | __packet_hook(prev, skb); | |
289 | return; | |
290 | ||
291 | out: | |
292 | if (!skb0) | |
293 | kfree_skb(skb); | |
294 | } | |
295 | ||
296 | /* called with rcu_read_lock */ | |
297 | void br_multicast_deliver(struct net_bridge_mdb_entry *mdst, | |
298 | struct sk_buff *skb) | |
299 | { | |
300 | br_multicast_flood(mdst, skb, NULL, __br_deliver); | |
301 | } | |
302 | ||
303 | /* called with rcu_read_lock */ | |
304 | void br_multicast_forward(struct net_bridge_mdb_entry *mdst, | |
305 | struct sk_buff *skb, struct sk_buff *skb2) | |
306 | { | |
307 | br_multicast_flood(mdst, skb, skb2, __br_forward); | |
308 | } | |
309 | #endif |