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 | { | |
2594e906 NA |
33 | struct net_bridge_vlan_group *vg; |
34 | ||
35 | vg = nbp_vlan_group(p); | |
a97bfc1d | 36 | return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && |
2594e906 | 37 | br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING; |
1da177e4 LT |
38 | } |
39 | ||
0c4b51f0 | 40 | int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 41 | { |
df356d5e TM |
42 | if (!is_skb_forwardable(skb->dev, skb)) |
43 | goto drop; | |
44 | ||
45 | skb_push(skb, ETH_HLEN); | |
46 | br_drop_fake_rtable(skb); | |
47 | skb_sender_cpu_clear(skb); | |
48 | ||
49 | if (skb->ip_summed == CHECKSUM_PARTIAL && | |
50 | (skb->protocol == htons(ETH_P_8021Q) || | |
51 | skb->protocol == htons(ETH_P_8021AD))) { | |
52 | int depth; | |
53 | ||
54 | if (!__vlan_get_protocol(skb, skb->protocol, &depth)) | |
55 | goto drop; | |
56 | ||
57 | skb_set_network_header(skb, depth); | |
1da177e4 LT |
58 | } |
59 | ||
df356d5e TM |
60 | dev_queue_xmit(skb); |
61 | ||
62 | return 0; | |
63 | ||
64 | drop: | |
65 | kfree_skb(skb); | |
1da177e4 LT |
66 | return 0; |
67 | } | |
34666d46 | 68 | EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit); |
1da177e4 | 69 | |
0c4b51f0 | 70 | int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 71 | { |
29a26a56 EB |
72 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, |
73 | net, sk, skb, NULL, skb->dev, | |
9ef513be | 74 | br_dev_queue_push_xmit); |
1da177e4 | 75 | |
1da177e4 | 76 | } |
34666d46 | 77 | EXPORT_SYMBOL_GPL(br_forward_finish); |
1da177e4 LT |
78 | |
79 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
80 | { | |
2594e906 NA |
81 | struct net_bridge_vlan_group *vg; |
82 | ||
83 | vg = nbp_vlan_group(to); | |
84 | skb = br_handle_vlan(to->br, vg, skb); | |
78851988 VY |
85 | if (!skb) |
86 | return; | |
87 | ||
1da177e4 | 88 | skb->dev = to->dev; |
91d2c34a | 89 | |
e15c3c22 | 90 | if (unlikely(netpoll_tx_running(to->br->dev))) { |
f6367b46 | 91 | if (!is_skb_forwardable(skb->dev, skb)) |
91d2c34a HX |
92 | kfree_skb(skb); |
93 | else { | |
94 | skb_push(skb, ETH_HLEN); | |
95 | br_netpoll_send_skb(to, skb); | |
96 | } | |
97 | return; | |
98 | } | |
99 | ||
29a26a56 EB |
100 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, |
101 | dev_net(skb->dev), NULL, skb,NULL, skb->dev, | |
713aefa3 | 102 | br_forward_finish); |
1da177e4 LT |
103 | } |
104 | ||
105 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
106 | { | |
2594e906 | 107 | struct net_bridge_vlan_group *vg; |
1da177e4 LT |
108 | struct net_device *indev; |
109 | ||
4906f998 HX |
110 | if (skb_warn_if_lro(skb)) { |
111 | kfree_skb(skb); | |
112 | return; | |
113 | } | |
114 | ||
2594e906 NA |
115 | vg = nbp_vlan_group(to); |
116 | skb = br_handle_vlan(to->br, vg, skb); | |
78851988 VY |
117 | if (!skb) |
118 | return; | |
119 | ||
1da177e4 LT |
120 | indev = skb->dev; |
121 | skb->dev = to->dev; | |
35fc92a9 | 122 | skb_forward_csum(skb); |
1da177e4 | 123 | |
29a26a56 EB |
124 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, |
125 | dev_net(indev), NULL, skb, indev, skb->dev, | |
713aefa3 | 126 | br_forward_finish); |
1da177e4 LT |
127 | } |
128 | ||
129 | /* called with rcu_read_lock */ | |
130 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
131 | { | |
43598813 | 132 | if (to && should_deliver(to, skb)) { |
1da177e4 LT |
133 | __br_deliver(to, skb); |
134 | return; | |
135 | } | |
136 | ||
137 | kfree_skb(skb); | |
138 | } | |
523b929d | 139 | EXPORT_SYMBOL_GPL(br_deliver); |
1da177e4 LT |
140 | |
141 | /* called with rcu_read_lock */ | |
7f7708f0 | 142 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0) |
1da177e4 | 143 | { |
4906f998 | 144 | if (should_deliver(to, skb)) { |
7f7708f0 MB |
145 | if (skb0) |
146 | deliver_clone(to, skb, __br_forward); | |
147 | else | |
148 | __br_forward(to, skb); | |
1da177e4 LT |
149 | return; |
150 | } | |
151 | ||
7f7708f0 MB |
152 | if (!skb0) |
153 | kfree_skb(skb); | |
1da177e4 LT |
154 | } |
155 | ||
87faf3cc DM |
156 | static int deliver_clone(const struct net_bridge_port *prev, |
157 | struct sk_buff *skb, | |
025d89c2 HX |
158 | void (*__packet_hook)(const struct net_bridge_port *p, |
159 | struct sk_buff *skb)) | |
160 | { | |
fed396a5 HX |
161 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
162 | ||
025d89c2 HX |
163 | skb = skb_clone(skb, GFP_ATOMIC); |
164 | if (!skb) { | |
025d89c2 HX |
165 | dev->stats.tx_dropped++; |
166 | return -ENOMEM; | |
167 | } | |
168 | ||
169 | __packet_hook(prev, skb); | |
170 | return 0; | |
171 | } | |
172 | ||
173 | static struct net_bridge_port *maybe_deliver( | |
174 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
175 | struct sk_buff *skb, | |
176 | void (*__packet_hook)(const struct net_bridge_port *p, | |
177 | struct sk_buff *skb)) | |
178 | { | |
179 | int err; | |
180 | ||
181 | if (!should_deliver(p, skb)) | |
182 | return prev; | |
183 | ||
184 | if (!prev) | |
185 | goto out; | |
186 | ||
187 | err = deliver_clone(prev, skb, __packet_hook); | |
188 | if (err) | |
189 | return ERR_PTR(err); | |
190 | ||
191 | out: | |
192 | return p; | |
193 | } | |
194 | ||
1da177e4 | 195 | /* called under bridge lock */ |
e081e1e3 | 196 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
b33084be HX |
197 | struct sk_buff *skb0, |
198 | void (*__packet_hook)(const struct net_bridge_port *p, | |
867a5943 VY |
199 | struct sk_buff *skb), |
200 | bool unicast) | |
1da177e4 LT |
201 | { |
202 | struct net_bridge_port *p; | |
203 | struct net_bridge_port *prev; | |
204 | ||
1da177e4 LT |
205 | prev = NULL; |
206 | ||
207 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
867a5943 VY |
208 | /* Do not flood unicast traffic to ports that turn it off */ |
209 | if (unicast && !(p->flags & BR_FLOOD)) | |
210 | continue; | |
95850116 KP |
211 | |
212 | /* Do not flood to ports that enable proxy ARP */ | |
213 | if (p->flags & BR_PROXYARP) | |
214 | continue; | |
842a9ae0 JM |
215 | if ((p->flags & BR_PROXYARP_WIFI) && |
216 | BR_INPUT_SKB_CB(skb)->proxyarp_replied) | |
217 | continue; | |
95850116 | 218 | |
025d89c2 HX |
219 | prev = maybe_deliver(prev, p, skb, __packet_hook); |
220 | if (IS_ERR(prev)) | |
221 | goto out; | |
1da177e4 LT |
222 | } |
223 | ||
b33084be HX |
224 | if (!prev) |
225 | goto out; | |
226 | ||
025d89c2 HX |
227 | if (skb0) |
228 | deliver_clone(prev, skb, __packet_hook); | |
229 | else | |
230 | __packet_hook(prev, skb); | |
b33084be | 231 | return; |
1da177e4 | 232 | |
b33084be HX |
233 | out: |
234 | if (!skb0) | |
235 | kfree_skb(skb); | |
1da177e4 LT |
236 | } |
237 | ||
238 | ||
239 | /* called with rcu_read_lock */ | |
867a5943 | 240 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast) |
1da177e4 | 241 | { |
867a5943 | 242 | br_flood(br, skb, NULL, __br_deliver, unicast); |
1da177e4 LT |
243 | } |
244 | ||
245 | /* called under bridge lock */ | |
b33084be | 246 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, |
867a5943 | 247 | struct sk_buff *skb2, bool unicast) |
1da177e4 | 248 | { |
867a5943 | 249 | br_flood(br, skb, skb2, __br_forward, unicast); |
1da177e4 | 250 | } |
5cb5e947 HX |
251 | |
252 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING | |
253 | /* called with rcu_read_lock */ | |
254 | static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, | |
255 | struct sk_buff *skb, struct sk_buff *skb0, | |
256 | void (*__packet_hook)( | |
257 | const struct net_bridge_port *p, | |
258 | struct sk_buff *skb)) | |
259 | { | |
260 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
261 | struct net_bridge *br = netdev_priv(dev); | |
afe0159d | 262 | struct net_bridge_port *prev = NULL; |
5cb5e947 HX |
263 | struct net_bridge_port_group *p; |
264 | struct hlist_node *rp; | |
265 | ||
e8051688 | 266 | rp = rcu_dereference(hlist_first_rcu(&br->router_list)); |
83f6a740 | 267 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 | 268 | while (p || rp) { |
afe0159d | 269 | struct net_bridge_port *port, *lport, *rport; |
270 | ||
5cb5e947 HX |
271 | lport = p ? p->port : NULL; |
272 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
273 | NULL; | |
274 | ||
275 | port = (unsigned long)lport > (unsigned long)rport ? | |
276 | lport : rport; | |
277 | ||
278 | prev = maybe_deliver(prev, port, skb, __packet_hook); | |
279 | if (IS_ERR(prev)) | |
280 | goto out; | |
281 | ||
282 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 283 | p = rcu_dereference(p->next); |
5cb5e947 | 284 | if ((unsigned long)rport >= (unsigned long)port) |
e8051688 | 285 | rp = rcu_dereference(hlist_next_rcu(rp)); |
5cb5e947 HX |
286 | } |
287 | ||
288 | if (!prev) | |
289 | goto out; | |
290 | ||
291 | if (skb0) | |
292 | deliver_clone(prev, skb, __packet_hook); | |
293 | else | |
294 | __packet_hook(prev, skb); | |
295 | return; | |
296 | ||
297 | out: | |
298 | if (!skb0) | |
299 | kfree_skb(skb); | |
300 | } | |
301 | ||
302 | /* called with rcu_read_lock */ | |
303 | void br_multicast_deliver(struct net_bridge_mdb_entry *mdst, | |
304 | struct sk_buff *skb) | |
305 | { | |
306 | br_multicast_flood(mdst, skb, NULL, __br_deliver); | |
307 | } | |
308 | ||
309 | /* called with rcu_read_lock */ | |
310 | void br_multicast_forward(struct net_bridge_mdb_entry *mdst, | |
311 | struct sk_buff *skb, struct sk_buff *skb2) | |
312 | { | |
313 | br_multicast_flood(mdst, skb, skb2, __br_forward); | |
314 | } | |
315 | #endif |