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 | ||
95c96174 | 37 | static inline unsigned int packet_length(const struct sk_buff *skb) |
85ca719e SH |
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 | { | |
f88de8de CG |
44 | /* ip_fragment doesn't copy the MAC header */ |
45 | if (nf_bridge_maybe_copy_header(skb) || | |
46 | (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))) { | |
1da177e4 | 47 | kfree_skb(skb); |
f88de8de CG |
48 | } else { |
49 | skb_push(skb, ETH_HLEN); | |
a881e963 | 50 | br_drop_fake_rtable(skb); |
f88de8de | 51 | dev_queue_xmit(skb); |
1da177e4 LT |
52 | } |
53 | ||
54 | return 0; | |
55 | } | |
56 | ||
57 | int br_forward_finish(struct sk_buff *skb) | |
58 | { | |
713aefa3 | 59 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, |
9ef513be | 60 | br_dev_queue_push_xmit); |
1da177e4 | 61 | |
1da177e4 LT |
62 | } |
63 | ||
64 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
65 | { | |
66 | skb->dev = to->dev; | |
91d2c34a | 67 | |
e15c3c22 | 68 | if (unlikely(netpoll_tx_running(to->br->dev))) { |
91d2c34a HX |
69 | if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) |
70 | kfree_skb(skb); | |
71 | else { | |
72 | skb_push(skb, ETH_HLEN); | |
73 | br_netpoll_send_skb(to, skb); | |
74 | } | |
75 | return; | |
76 | } | |
77 | ||
713aefa3 JE |
78 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
79 | br_forward_finish); | |
1da177e4 LT |
80 | } |
81 | ||
82 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
83 | { | |
84 | struct net_device *indev; | |
85 | ||
4906f998 HX |
86 | if (skb_warn_if_lro(skb)) { |
87 | kfree_skb(skb); | |
88 | return; | |
89 | } | |
90 | ||
1da177e4 LT |
91 | indev = skb->dev; |
92 | skb->dev = to->dev; | |
35fc92a9 | 93 | skb_forward_csum(skb); |
1da177e4 | 94 | |
713aefa3 JE |
95 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev, |
96 | br_forward_finish); | |
1da177e4 LT |
97 | } |
98 | ||
99 | /* called with rcu_read_lock */ | |
100 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
101 | { | |
43598813 | 102 | if (to && should_deliver(to, skb)) { |
1da177e4 LT |
103 | __br_deliver(to, skb); |
104 | return; | |
105 | } | |
106 | ||
107 | kfree_skb(skb); | |
108 | } | |
109 | ||
110 | /* called with rcu_read_lock */ | |
7f7708f0 | 111 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0) |
1da177e4 | 112 | { |
4906f998 | 113 | if (should_deliver(to, skb)) { |
7f7708f0 MB |
114 | if (skb0) |
115 | deliver_clone(to, skb, __br_forward); | |
116 | else | |
117 | __br_forward(to, skb); | |
1da177e4 LT |
118 | return; |
119 | } | |
120 | ||
7f7708f0 MB |
121 | if (!skb0) |
122 | kfree_skb(skb); | |
1da177e4 LT |
123 | } |
124 | ||
87faf3cc DM |
125 | static int deliver_clone(const struct net_bridge_port *prev, |
126 | struct sk_buff *skb, | |
025d89c2 HX |
127 | void (*__packet_hook)(const struct net_bridge_port *p, |
128 | struct sk_buff *skb)) | |
129 | { | |
fed396a5 HX |
130 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
131 | ||
025d89c2 HX |
132 | skb = skb_clone(skb, GFP_ATOMIC); |
133 | if (!skb) { | |
025d89c2 HX |
134 | dev->stats.tx_dropped++; |
135 | return -ENOMEM; | |
136 | } | |
137 | ||
138 | __packet_hook(prev, skb); | |
139 | return 0; | |
140 | } | |
141 | ||
142 | static struct net_bridge_port *maybe_deliver( | |
143 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
144 | struct sk_buff *skb, | |
145 | void (*__packet_hook)(const struct net_bridge_port *p, | |
146 | struct sk_buff *skb)) | |
147 | { | |
148 | int err; | |
149 | ||
150 | if (!should_deliver(p, skb)) | |
151 | return prev; | |
152 | ||
153 | if (!prev) | |
154 | goto out; | |
155 | ||
156 | err = deliver_clone(prev, skb, __packet_hook); | |
157 | if (err) | |
158 | return ERR_PTR(err); | |
159 | ||
160 | out: | |
161 | return p; | |
162 | } | |
163 | ||
1da177e4 | 164 | /* called under bridge lock */ |
e081e1e3 | 165 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
b33084be HX |
166 | struct sk_buff *skb0, |
167 | void (*__packet_hook)(const struct net_bridge_port *p, | |
168 | struct sk_buff *skb)) | |
1da177e4 LT |
169 | { |
170 | struct net_bridge_port *p; | |
171 | struct net_bridge_port *prev; | |
172 | ||
1da177e4 LT |
173 | prev = NULL; |
174 | ||
175 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
025d89c2 HX |
176 | prev = maybe_deliver(prev, p, skb, __packet_hook); |
177 | if (IS_ERR(prev)) | |
178 | goto out; | |
1da177e4 LT |
179 | } |
180 | ||
b33084be HX |
181 | if (!prev) |
182 | goto out; | |
183 | ||
025d89c2 HX |
184 | if (skb0) |
185 | deliver_clone(prev, skb, __packet_hook); | |
186 | else | |
187 | __packet_hook(prev, skb); | |
b33084be | 188 | return; |
1da177e4 | 189 | |
b33084be HX |
190 | out: |
191 | if (!skb0) | |
192 | kfree_skb(skb); | |
1da177e4 LT |
193 | } |
194 | ||
195 | ||
196 | /* called with rcu_read_lock */ | |
e081e1e3 | 197 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 198 | { |
b33084be | 199 | br_flood(br, skb, NULL, __br_deliver); |
1da177e4 LT |
200 | } |
201 | ||
202 | /* called under bridge lock */ | |
b33084be HX |
203 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, |
204 | struct sk_buff *skb2) | |
1da177e4 | 205 | { |
b33084be | 206 | br_flood(br, skb, skb2, __br_forward); |
1da177e4 | 207 | } |
5cb5e947 HX |
208 | |
209 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING | |
210 | /* called with rcu_read_lock */ | |
211 | static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, | |
212 | struct sk_buff *skb, struct sk_buff *skb0, | |
213 | void (*__packet_hook)( | |
214 | const struct net_bridge_port *p, | |
215 | struct sk_buff *skb)) | |
216 | { | |
217 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
218 | struct net_bridge *br = netdev_priv(dev); | |
afe0159d | 219 | struct net_bridge_port *prev = NULL; |
5cb5e947 HX |
220 | struct net_bridge_port_group *p; |
221 | struct hlist_node *rp; | |
222 | ||
e8051688 | 223 | rp = rcu_dereference(hlist_first_rcu(&br->router_list)); |
83f6a740 | 224 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 | 225 | while (p || rp) { |
afe0159d | 226 | struct net_bridge_port *port, *lport, *rport; |
227 | ||
5cb5e947 HX |
228 | lport = p ? p->port : NULL; |
229 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
230 | NULL; | |
231 | ||
232 | port = (unsigned long)lport > (unsigned long)rport ? | |
233 | lport : rport; | |
234 | ||
235 | prev = maybe_deliver(prev, port, skb, __packet_hook); | |
236 | if (IS_ERR(prev)) | |
237 | goto out; | |
238 | ||
239 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 240 | p = rcu_dereference(p->next); |
5cb5e947 | 241 | if ((unsigned long)rport >= (unsigned long)port) |
e8051688 | 242 | rp = rcu_dereference(hlist_next_rcu(rp)); |
5cb5e947 HX |
243 | } |
244 | ||
245 | if (!prev) | |
246 | goto out; | |
247 | ||
248 | if (skb0) | |
249 | deliver_clone(prev, skb, __packet_hook); | |
250 | else | |
251 | __packet_hook(prev, skb); | |
252 | return; | |
253 | ||
254 | out: | |
255 | if (!skb0) | |
256 | kfree_skb(skb); | |
257 | } | |
258 | ||
259 | /* called with rcu_read_lock */ | |
260 | void br_multicast_deliver(struct net_bridge_mdb_entry *mdst, | |
261 | struct sk_buff *skb) | |
262 | { | |
263 | br_multicast_flood(mdst, skb, NULL, __br_deliver); | |
264 | } | |
265 | ||
266 | /* called with rcu_read_lock */ | |
267 | void br_multicast_forward(struct net_bridge_mdb_entry *mdst, | |
268 | struct sk_buff *skb, struct sk_buff *skb2) | |
269 | { | |
270 | br_multicast_flood(mdst, skb, skb2, __br_forward); | |
271 | } | |
272 | #endif |