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Commit | Line | Data |
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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> |
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/netdevice.h> | |
17 | #include <linux/skbuff.h> | |
85ca719e | 18 | #include <linux/if_vlan.h> |
1da177e4 LT |
19 | #include <linux/netfilter_bridge.h> |
20 | #include "br_private.h" | |
21 | ||
7f7708f0 MB |
22 | static int deliver_clone(struct net_bridge_port *prev, struct sk_buff *skb, |
23 | void (*__packet_hook)(const struct net_bridge_port *p, | |
24 | struct sk_buff *skb)); | |
25 | ||
9ef513be | 26 | /* Don't forward packets to originating port or forwarding diasabled */ |
9d6f229f | 27 | static inline int should_deliver(const struct net_bridge_port *p, |
1da177e4 LT |
28 | const struct sk_buff *skb) |
29 | { | |
3982d3d2 FA |
30 | return (((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && |
31 | p->state == BR_STATE_FORWARDING); | |
1da177e4 LT |
32 | } |
33 | ||
85ca719e SH |
34 | static inline unsigned packet_length(const struct sk_buff *skb) |
35 | { | |
36 | return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
37 | } | |
38 | ||
1da177e4 LT |
39 | int br_dev_queue_push_xmit(struct sk_buff *skb) |
40 | { | |
7967168c | 41 | /* drop mtu oversized packets except gso */ |
89114afd | 42 | if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) |
1da177e4 LT |
43 | kfree_skb(skb); |
44 | else { | |
1da177e4 | 45 | /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */ |
3a13813e SH |
46 | if (nf_bridge_maybe_copy_header(skb)) |
47 | kfree_skb(skb); | |
07317621 | 48 | else { |
3a13813e | 49 | skb_push(skb, ETH_HLEN); |
1da177e4 | 50 | |
3a13813e SH |
51 | dev_queue_xmit(skb); |
52 | } | |
1da177e4 LT |
53 | } |
54 | ||
55 | return 0; | |
56 | } | |
57 | ||
58 | int br_forward_finish(struct sk_buff *skb) | |
59 | { | |
9ef513be SH |
60 | return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, |
61 | br_dev_queue_push_xmit); | |
1da177e4 | 62 | |
1da177e4 LT |
63 | } |
64 | ||
65 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
66 | { | |
67 | skb->dev = to->dev; | |
1da177e4 LT |
68 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
69 | br_forward_finish); | |
70 | } | |
71 | ||
72 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
73 | { | |
74 | struct net_device *indev; | |
75 | ||
4906f998 HX |
76 | if (skb_warn_if_lro(skb)) { |
77 | kfree_skb(skb); | |
78 | return; | |
79 | } | |
80 | ||
1da177e4 LT |
81 | indev = skb->dev; |
82 | skb->dev = to->dev; | |
35fc92a9 | 83 | skb_forward_csum(skb); |
1da177e4 LT |
84 | |
85 | NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev, | |
86 | br_forward_finish); | |
87 | } | |
88 | ||
89 | /* called with rcu_read_lock */ | |
90 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
91 | { | |
92 | if (should_deliver(to, skb)) { | |
93 | __br_deliver(to, skb); | |
94 | return; | |
95 | } | |
96 | ||
97 | kfree_skb(skb); | |
98 | } | |
99 | ||
100 | /* called with rcu_read_lock */ | |
7f7708f0 | 101 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0) |
1da177e4 | 102 | { |
4906f998 | 103 | if (should_deliver(to, skb)) { |
7f7708f0 MB |
104 | if (skb0) |
105 | deliver_clone(to, skb, __br_forward); | |
106 | else | |
107 | __br_forward(to, skb); | |
1da177e4 LT |
108 | return; |
109 | } | |
110 | ||
7f7708f0 MB |
111 | if (!skb0) |
112 | kfree_skb(skb); | |
1da177e4 LT |
113 | } |
114 | ||
025d89c2 HX |
115 | static int deliver_clone(struct net_bridge_port *prev, struct sk_buff *skb, |
116 | void (*__packet_hook)(const struct net_bridge_port *p, | |
117 | struct sk_buff *skb)) | |
118 | { | |
119 | skb = skb_clone(skb, GFP_ATOMIC); | |
120 | if (!skb) { | |
121 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
122 | ||
123 | dev->stats.tx_dropped++; | |
124 | return -ENOMEM; | |
125 | } | |
126 | ||
127 | __packet_hook(prev, skb); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static struct net_bridge_port *maybe_deliver( | |
132 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
133 | struct sk_buff *skb, | |
134 | void (*__packet_hook)(const struct net_bridge_port *p, | |
135 | struct sk_buff *skb)) | |
136 | { | |
137 | int err; | |
138 | ||
139 | if (!should_deliver(p, skb)) | |
140 | return prev; | |
141 | ||
142 | if (!prev) | |
143 | goto out; | |
144 | ||
145 | err = deliver_clone(prev, skb, __packet_hook); | |
146 | if (err) | |
147 | return ERR_PTR(err); | |
148 | ||
149 | out: | |
150 | return p; | |
151 | } | |
152 | ||
1da177e4 | 153 | /* called under bridge lock */ |
e081e1e3 | 154 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
b33084be HX |
155 | struct sk_buff *skb0, |
156 | void (*__packet_hook)(const struct net_bridge_port *p, | |
157 | struct sk_buff *skb)) | |
1da177e4 LT |
158 | { |
159 | struct net_bridge_port *p; | |
160 | struct net_bridge_port *prev; | |
161 | ||
1da177e4 LT |
162 | prev = NULL; |
163 | ||
164 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
025d89c2 HX |
165 | prev = maybe_deliver(prev, p, skb, __packet_hook); |
166 | if (IS_ERR(prev)) | |
167 | goto out; | |
1da177e4 LT |
168 | } |
169 | ||
b33084be HX |
170 | if (!prev) |
171 | goto out; | |
172 | ||
025d89c2 HX |
173 | if (skb0) |
174 | deliver_clone(prev, skb, __packet_hook); | |
175 | else | |
176 | __packet_hook(prev, skb); | |
b33084be | 177 | return; |
1da177e4 | 178 | |
b33084be HX |
179 | out: |
180 | if (!skb0) | |
181 | kfree_skb(skb); | |
1da177e4 LT |
182 | } |
183 | ||
184 | ||
185 | /* called with rcu_read_lock */ | |
e081e1e3 | 186 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 187 | { |
b33084be | 188 | br_flood(br, skb, NULL, __br_deliver); |
1da177e4 LT |
189 | } |
190 | ||
191 | /* called under bridge lock */ | |
b33084be HX |
192 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, |
193 | struct sk_buff *skb2) | |
1da177e4 | 194 | { |
b33084be | 195 | br_flood(br, skb, skb2, __br_forward); |
1da177e4 | 196 | } |
5cb5e947 HX |
197 | |
198 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING | |
199 | /* called with rcu_read_lock */ | |
200 | static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, | |
201 | struct sk_buff *skb, struct sk_buff *skb0, | |
202 | void (*__packet_hook)( | |
203 | const struct net_bridge_port *p, | |
204 | struct sk_buff *skb)) | |
205 | { | |
206 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
207 | struct net_bridge *br = netdev_priv(dev); | |
208 | struct net_bridge_port *port; | |
209 | struct net_bridge_port *lport, *rport; | |
210 | struct net_bridge_port *prev; | |
211 | struct net_bridge_port_group *p; | |
212 | struct hlist_node *rp; | |
213 | ||
214 | prev = NULL; | |
215 | ||
216 | rp = br->router_list.first; | |
217 | p = mdst ? mdst->ports : NULL; | |
218 | while (p || rp) { | |
219 | lport = p ? p->port : NULL; | |
220 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
221 | NULL; | |
222 | ||
223 | port = (unsigned long)lport > (unsigned long)rport ? | |
224 | lport : rport; | |
225 | ||
226 | prev = maybe_deliver(prev, port, skb, __packet_hook); | |
227 | if (IS_ERR(prev)) | |
228 | goto out; | |
229 | ||
230 | if ((unsigned long)lport >= (unsigned long)port) | |
231 | p = p->next; | |
232 | if ((unsigned long)rport >= (unsigned long)port) | |
233 | rp = rp->next; | |
234 | } | |
235 | ||
236 | if (!prev) | |
237 | goto out; | |
238 | ||
239 | if (skb0) | |
240 | deliver_clone(prev, skb, __packet_hook); | |
241 | else | |
242 | __packet_hook(prev, skb); | |
243 | return; | |
244 | ||
245 | out: | |
246 | if (!skb0) | |
247 | kfree_skb(skb); | |
248 | } | |
249 | ||
250 | /* called with rcu_read_lock */ | |
251 | void br_multicast_deliver(struct net_bridge_mdb_entry *mdst, | |
252 | struct sk_buff *skb) | |
253 | { | |
254 | br_multicast_flood(mdst, skb, NULL, __br_deliver); | |
255 | } | |
256 | ||
257 | /* called with rcu_read_lock */ | |
258 | void br_multicast_forward(struct net_bridge_mdb_entry *mdst, | |
259 | struct sk_buff *skb, struct sk_buff *skb2) | |
260 | { | |
261 | br_multicast_flood(mdst, skb, skb2, __br_forward); | |
262 | } | |
263 | #endif |