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 | ||
9ef513be | 29 | /* Don't forward packets to originating port or forwarding diasabled */ |
9d6f229f | 30 | static inline int should_deliver(const struct net_bridge_port *p, |
1da177e4 LT |
31 | const struct sk_buff *skb) |
32 | { | |
3982d3d2 FA |
33 | return (((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && |
34 | p->state == BR_STATE_FORWARDING); | |
1da177e4 LT |
35 | } |
36 | ||
85ca719e SH |
37 | static inline unsigned packet_length(const struct sk_buff *skb) |
38 | { | |
39 | return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
40 | } | |
41 | ||
1da177e4 LT |
42 | int br_dev_queue_push_xmit(struct sk_buff *skb) |
43 | { | |
7967168c | 44 | /* drop mtu oversized packets except gso */ |
89114afd | 45 | if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) |
1da177e4 LT |
46 | kfree_skb(skb); |
47 | else { | |
e26c28e8 | 48 | /* ip_fragment doesn't copy the MAC header */ |
3a13813e SH |
49 | if (nf_bridge_maybe_copy_header(skb)) |
50 | kfree_skb(skb); | |
07317621 | 51 | else { |
3a13813e | 52 | skb_push(skb, ETH_HLEN); |
91d2c34a | 53 | dev_queue_xmit(skb); |
3a13813e | 54 | } |
1da177e4 LT |
55 | } |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | int br_forward_finish(struct sk_buff *skb) | |
61 | { | |
713aefa3 | 62 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, |
9ef513be | 63 | br_dev_queue_push_xmit); |
1da177e4 | 64 | |
1da177e4 LT |
65 | } |
66 | ||
67 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
68 | { | |
69 | skb->dev = to->dev; | |
91d2c34a HX |
70 | |
71 | if (unlikely(netpoll_tx_running(to->dev))) { | |
72 | if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) | |
73 | kfree_skb(skb); | |
74 | else { | |
75 | skb_push(skb, ETH_HLEN); | |
76 | br_netpoll_send_skb(to, skb); | |
77 | } | |
78 | return; | |
79 | } | |
80 | ||
713aefa3 JE |
81 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
82 | br_forward_finish); | |
1da177e4 LT |
83 | } |
84 | ||
85 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
86 | { | |
87 | struct net_device *indev; | |
88 | ||
4906f998 HX |
89 | if (skb_warn_if_lro(skb)) { |
90 | kfree_skb(skb); | |
91 | return; | |
92 | } | |
93 | ||
1da177e4 LT |
94 | indev = skb->dev; |
95 | skb->dev = to->dev; | |
35fc92a9 | 96 | skb_forward_csum(skb); |
1da177e4 | 97 | |
713aefa3 JE |
98 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev, |
99 | br_forward_finish); | |
1da177e4 LT |
100 | } |
101 | ||
102 | /* called with rcu_read_lock */ | |
103 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
104 | { | |
105 | if (should_deliver(to, skb)) { | |
106 | __br_deliver(to, skb); | |
107 | return; | |
108 | } | |
109 | ||
110 | kfree_skb(skb); | |
111 | } | |
112 | ||
113 | /* called with rcu_read_lock */ | |
7f7708f0 | 114 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0) |
1da177e4 | 115 | { |
4906f998 | 116 | if (should_deliver(to, skb)) { |
7f7708f0 MB |
117 | if (skb0) |
118 | deliver_clone(to, skb, __br_forward); | |
119 | else | |
120 | __br_forward(to, skb); | |
1da177e4 LT |
121 | return; |
122 | } | |
123 | ||
7f7708f0 MB |
124 | if (!skb0) |
125 | kfree_skb(skb); | |
1da177e4 LT |
126 | } |
127 | ||
87faf3cc DM |
128 | static int deliver_clone(const struct net_bridge_port *prev, |
129 | struct sk_buff *skb, | |
025d89c2 HX |
130 | void (*__packet_hook)(const struct net_bridge_port *p, |
131 | struct sk_buff *skb)) | |
132 | { | |
fed396a5 HX |
133 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
134 | ||
025d89c2 HX |
135 | skb = skb_clone(skb, GFP_ATOMIC); |
136 | if (!skb) { | |
025d89c2 HX |
137 | dev->stats.tx_dropped++; |
138 | return -ENOMEM; | |
139 | } | |
140 | ||
141 | __packet_hook(prev, skb); | |
142 | return 0; | |
143 | } | |
144 | ||
145 | static struct net_bridge_port *maybe_deliver( | |
146 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
147 | struct sk_buff *skb, | |
148 | void (*__packet_hook)(const struct net_bridge_port *p, | |
149 | struct sk_buff *skb)) | |
150 | { | |
151 | int err; | |
152 | ||
153 | if (!should_deliver(p, skb)) | |
154 | return prev; | |
155 | ||
156 | if (!prev) | |
157 | goto out; | |
158 | ||
159 | err = deliver_clone(prev, skb, __packet_hook); | |
160 | if (err) | |
161 | return ERR_PTR(err); | |
162 | ||
163 | out: | |
164 | return p; | |
165 | } | |
166 | ||
1da177e4 | 167 | /* called under bridge lock */ |
e081e1e3 | 168 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
b33084be HX |
169 | struct sk_buff *skb0, |
170 | void (*__packet_hook)(const struct net_bridge_port *p, | |
171 | struct sk_buff *skb)) | |
1da177e4 LT |
172 | { |
173 | struct net_bridge_port *p; | |
174 | struct net_bridge_port *prev; | |
175 | ||
1da177e4 LT |
176 | prev = NULL; |
177 | ||
178 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
025d89c2 HX |
179 | prev = maybe_deliver(prev, p, skb, __packet_hook); |
180 | if (IS_ERR(prev)) | |
181 | goto out; | |
1da177e4 LT |
182 | } |
183 | ||
b33084be HX |
184 | if (!prev) |
185 | goto out; | |
186 | ||
025d89c2 HX |
187 | if (skb0) |
188 | deliver_clone(prev, skb, __packet_hook); | |
189 | else | |
190 | __packet_hook(prev, skb); | |
b33084be | 191 | return; |
1da177e4 | 192 | |
b33084be HX |
193 | out: |
194 | if (!skb0) | |
195 | kfree_skb(skb); | |
1da177e4 LT |
196 | } |
197 | ||
198 | ||
199 | /* called with rcu_read_lock */ | |
e081e1e3 | 200 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 201 | { |
b33084be | 202 | br_flood(br, skb, NULL, __br_deliver); |
1da177e4 LT |
203 | } |
204 | ||
205 | /* called under bridge lock */ | |
b33084be HX |
206 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, |
207 | struct sk_buff *skb2) | |
1da177e4 | 208 | { |
b33084be | 209 | br_flood(br, skb, skb2, __br_forward); |
1da177e4 | 210 | } |
5cb5e947 HX |
211 | |
212 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING | |
213 | /* called with rcu_read_lock */ | |
214 | static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, | |
215 | struct sk_buff *skb, struct sk_buff *skb0, | |
216 | void (*__packet_hook)( | |
217 | const struct net_bridge_port *p, | |
218 | struct sk_buff *skb)) | |
219 | { | |
220 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
221 | struct net_bridge *br = netdev_priv(dev); | |
afe0159d | 222 | struct net_bridge_port *prev = NULL; |
5cb5e947 HX |
223 | struct net_bridge_port_group *p; |
224 | struct hlist_node *rp; | |
225 | ||
168d40ee | 226 | rp = rcu_dereference(br->router_list.first); |
83f6a740 | 227 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 | 228 | while (p || rp) { |
afe0159d | 229 | struct net_bridge_port *port, *lport, *rport; |
230 | ||
5cb5e947 HX |
231 | lport = p ? p->port : NULL; |
232 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
233 | NULL; | |
234 | ||
235 | port = (unsigned long)lport > (unsigned long)rport ? | |
236 | lport : rport; | |
237 | ||
238 | prev = maybe_deliver(prev, port, skb, __packet_hook); | |
239 | if (IS_ERR(prev)) | |
240 | goto out; | |
241 | ||
242 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 243 | p = rcu_dereference(p->next); |
5cb5e947 | 244 | if ((unsigned long)rport >= (unsigned long)port) |
168d40ee | 245 | rp = rcu_dereference(rp->next); |
5cb5e947 HX |
246 | } |
247 | ||
248 | if (!prev) | |
249 | goto out; | |
250 | ||
251 | if (skb0) | |
252 | deliver_clone(prev, skb, __packet_hook); | |
253 | else | |
254 | __packet_hook(prev, skb); | |
255 | return; | |
256 | ||
257 | out: | |
258 | if (!skb0) | |
259 | kfree_skb(skb); | |
260 | } | |
261 | ||
262 | /* called with rcu_read_lock */ | |
263 | void br_multicast_deliver(struct net_bridge_mdb_entry *mdst, | |
264 | struct sk_buff *skb) | |
265 | { | |
266 | br_multicast_flood(mdst, skb, NULL, __br_deliver); | |
267 | } | |
268 | ||
269 | /* called with rcu_read_lock */ | |
270 | void br_multicast_forward(struct net_bridge_mdb_entry *mdst, | |
271 | struct sk_buff *skb, struct sk_buff *skb2) | |
272 | { | |
273 | br_multicast_flood(mdst, skb, skb2, __br_forward); | |
274 | } | |
275 | #endif |