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 | ||
907b1e6e | 35 | vg = nbp_vlan_group_rcu(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); | |
df356d5e TM |
47 | |
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); | |
1da177e4 LT |
57 | } |
58 | ||
df356d5e TM |
59 | dev_queue_xmit(skb); |
60 | ||
61 | return 0; | |
62 | ||
63 | drop: | |
64 | kfree_skb(skb); | |
1da177e4 LT |
65 | return 0; |
66 | } | |
34666d46 | 67 | EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit); |
1da177e4 | 68 | |
0c4b51f0 | 69 | int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 70 | { |
29a26a56 EB |
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 | { | |
2594e906 NA |
80 | struct net_bridge_vlan_group *vg; |
81 | ||
907b1e6e | 82 | vg = nbp_vlan_group_rcu(to); |
2594e906 | 83 | skb = br_handle_vlan(to->br, vg, skb); |
78851988 VY |
84 | if (!skb) |
85 | return; | |
86 | ||
1da177e4 | 87 | skb->dev = to->dev; |
91d2c34a | 88 | |
e15c3c22 | 89 | if (unlikely(netpoll_tx_running(to->br->dev))) { |
f6367b46 | 90 | if (!is_skb_forwardable(skb->dev, skb)) |
91d2c34a HX |
91 | kfree_skb(skb); |
92 | else { | |
93 | skb_push(skb, ETH_HLEN); | |
94 | br_netpoll_send_skb(to, skb); | |
95 | } | |
96 | return; | |
97 | } | |
98 | ||
29a26a56 EB |
99 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, |
100 | dev_net(skb->dev), NULL, skb,NULL, skb->dev, | |
713aefa3 | 101 | br_forward_finish); |
1da177e4 LT |
102 | } |
103 | ||
104 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
105 | { | |
2594e906 | 106 | struct net_bridge_vlan_group *vg; |
1da177e4 LT |
107 | struct net_device *indev; |
108 | ||
4906f998 HX |
109 | if (skb_warn_if_lro(skb)) { |
110 | kfree_skb(skb); | |
111 | return; | |
112 | } | |
113 | ||
907b1e6e | 114 | vg = nbp_vlan_group_rcu(to); |
2594e906 | 115 | skb = br_handle_vlan(to->br, vg, skb); |
78851988 VY |
116 | if (!skb) |
117 | return; | |
118 | ||
1da177e4 LT |
119 | indev = skb->dev; |
120 | skb->dev = to->dev; | |
35fc92a9 | 121 | skb_forward_csum(skb); |
1da177e4 | 122 | |
29a26a56 EB |
123 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, |
124 | dev_net(indev), NULL, skb, indev, skb->dev, | |
713aefa3 | 125 | br_forward_finish); |
1da177e4 LT |
126 | } |
127 | ||
128 | /* called with rcu_read_lock */ | |
129 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
130 | { | |
43598813 | 131 | if (to && should_deliver(to, skb)) { |
1da177e4 LT |
132 | __br_deliver(to, skb); |
133 | return; | |
134 | } | |
135 | ||
136 | kfree_skb(skb); | |
137 | } | |
523b929d | 138 | EXPORT_SYMBOL_GPL(br_deliver); |
1da177e4 LT |
139 | |
140 | /* called with rcu_read_lock */ | |
b35c5f63 NA |
141 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, |
142 | bool local_rcv) | |
1da177e4 | 143 | { |
b7af1472 | 144 | if (to && should_deliver(to, skb)) { |
b35c5f63 | 145 | if (local_rcv) |
7f7708f0 MB |
146 | deliver_clone(to, skb, __br_forward); |
147 | else | |
148 | __br_forward(to, skb); | |
1da177e4 LT |
149 | return; |
150 | } | |
151 | ||
b35c5f63 | 152 | if (!local_rcv) |
7f7708f0 | 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 | 197 | void (*__packet_hook)(const struct net_bridge_port *p, |
867a5943 | 198 | struct sk_buff *skb), |
b35c5f63 | 199 | bool local_rcv, bool unicast) |
1da177e4 | 200 | { |
1080ab95 | 201 | u8 igmp_type = br_multicast_igmp_type(skb); |
1da177e4 | 202 | struct net_bridge_port *prev; |
1080ab95 | 203 | struct net_bridge_port *p; |
1da177e4 | 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; | |
1080ab95 | 222 | if (prev == p) |
a65056ec | 223 | br_multicast_count(p->br, p, skb, igmp_type, |
1080ab95 | 224 | BR_MCAST_DIR_TX); |
1da177e4 LT |
225 | } |
226 | ||
b33084be HX |
227 | if (!prev) |
228 | goto out; | |
229 | ||
b35c5f63 | 230 | if (local_rcv) |
025d89c2 HX |
231 | deliver_clone(prev, skb, __packet_hook); |
232 | else | |
233 | __packet_hook(prev, skb); | |
b33084be | 234 | return; |
1da177e4 | 235 | |
b33084be | 236 | out: |
b35c5f63 | 237 | if (!local_rcv) |
b33084be | 238 | kfree_skb(skb); |
1da177e4 LT |
239 | } |
240 | ||
241 | ||
242 | /* called with rcu_read_lock */ | |
867a5943 | 243 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, bool unicast) |
1da177e4 | 244 | { |
b35c5f63 | 245 | br_flood(br, skb, __br_deliver, false, unicast); |
1da177e4 LT |
246 | } |
247 | ||
248 | /* called under bridge lock */ | |
b33084be | 249 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, |
b35c5f63 | 250 | bool local_rcv, bool unicast) |
1da177e4 | 251 | { |
b35c5f63 | 252 | br_flood(br, skb, __br_forward, local_rcv, unicast); |
1da177e4 | 253 | } |
5cb5e947 HX |
254 | |
255 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING | |
256 | /* called with rcu_read_lock */ | |
257 | static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, | |
b35c5f63 | 258 | struct sk_buff *skb, |
5cb5e947 HX |
259 | void (*__packet_hook)( |
260 | const struct net_bridge_port *p, | |
b35c5f63 NA |
261 | struct sk_buff *skb), |
262 | bool local_rcv) | |
5cb5e947 HX |
263 | { |
264 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
1080ab95 | 265 | u8 igmp_type = br_multicast_igmp_type(skb); |
5cb5e947 | 266 | struct net_bridge *br = netdev_priv(dev); |
afe0159d | 267 | struct net_bridge_port *prev = NULL; |
5cb5e947 HX |
268 | struct net_bridge_port_group *p; |
269 | struct hlist_node *rp; | |
270 | ||
e8051688 | 271 | rp = rcu_dereference(hlist_first_rcu(&br->router_list)); |
83f6a740 | 272 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 | 273 | while (p || rp) { |
afe0159d | 274 | struct net_bridge_port *port, *lport, *rport; |
275 | ||
5cb5e947 HX |
276 | lport = p ? p->port : NULL; |
277 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
278 | NULL; | |
279 | ||
280 | port = (unsigned long)lport > (unsigned long)rport ? | |
281 | lport : rport; | |
282 | ||
283 | prev = maybe_deliver(prev, port, skb, __packet_hook); | |
284 | if (IS_ERR(prev)) | |
285 | goto out; | |
1080ab95 | 286 | if (prev == port) |
a65056ec | 287 | br_multicast_count(port->br, port, skb, igmp_type, |
1080ab95 | 288 | BR_MCAST_DIR_TX); |
5cb5e947 HX |
289 | |
290 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 291 | p = rcu_dereference(p->next); |
5cb5e947 | 292 | if ((unsigned long)rport >= (unsigned long)port) |
e8051688 | 293 | rp = rcu_dereference(hlist_next_rcu(rp)); |
5cb5e947 HX |
294 | } |
295 | ||
296 | if (!prev) | |
297 | goto out; | |
298 | ||
b35c5f63 | 299 | if (local_rcv) |
5cb5e947 HX |
300 | deliver_clone(prev, skb, __packet_hook); |
301 | else | |
302 | __packet_hook(prev, skb); | |
303 | return; | |
304 | ||
305 | out: | |
b35c5f63 | 306 | if (!local_rcv) |
5cb5e947 HX |
307 | kfree_skb(skb); |
308 | } | |
309 | ||
310 | /* called with rcu_read_lock */ | |
311 | void br_multicast_deliver(struct net_bridge_mdb_entry *mdst, | |
312 | struct sk_buff *skb) | |
313 | { | |
b35c5f63 | 314 | br_multicast_flood(mdst, skb, __br_deliver, false); |
5cb5e947 HX |
315 | } |
316 | ||
317 | /* called with rcu_read_lock */ | |
318 | void br_multicast_forward(struct net_bridge_mdb_entry *mdst, | |
b35c5f63 | 319 | struct sk_buff *skb, bool local_rcv) |
5cb5e947 | 320 | { |
b35c5f63 | 321 | br_multicast_flood(mdst, skb, __br_forward, local_rcv); |
5cb5e947 HX |
322 | } |
323 | #endif |