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