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> | |
18 | #include <linux/skbuff.h> | |
85ca719e | 19 | #include <linux/if_vlan.h> |
1da177e4 LT |
20 | #include <linux/netfilter_bridge.h> |
21 | #include "br_private.h" | |
22 | ||
87faf3cc DM |
23 | static int deliver_clone(const struct net_bridge_port *prev, |
24 | struct sk_buff *skb, | |
7f7708f0 MB |
25 | void (*__packet_hook)(const struct net_bridge_port *p, |
26 | struct sk_buff *skb)); | |
27 | ||
9ef513be | 28 | /* Don't forward packets to originating port or forwarding diasabled */ |
9d6f229f | 29 | static inline int should_deliver(const struct net_bridge_port *p, |
1da177e4 LT |
30 | const struct sk_buff *skb) |
31 | { | |
3982d3d2 FA |
32 | return (((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && |
33 | p->state == BR_STATE_FORWARDING); | |
1da177e4 LT |
34 | } |
35 | ||
85ca719e SH |
36 | static inline unsigned packet_length(const struct sk_buff *skb) |
37 | { | |
38 | return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
39 | } | |
40 | ||
1da177e4 LT |
41 | int br_dev_queue_push_xmit(struct sk_buff *skb) |
42 | { | |
7967168c | 43 | /* drop mtu oversized packets except gso */ |
89114afd | 44 | if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) |
1da177e4 LT |
45 | kfree_skb(skb); |
46 | else { | |
1da177e4 | 47 | /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */ |
3a13813e SH |
48 | if (nf_bridge_maybe_copy_header(skb)) |
49 | kfree_skb(skb); | |
07317621 | 50 | else { |
3a13813e | 51 | skb_push(skb, ETH_HLEN); |
1da177e4 | 52 | |
3a13813e SH |
53 | dev_queue_xmit(skb); |
54 | } | |
1da177e4 LT |
55 | } |
56 | ||
57 | return 0; | |
58 | } | |
59 | ||
60 | int br_forward_finish(struct sk_buff *skb) | |
61 | { | |
9ef513be SH |
62 | return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, |
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; | |
1da177e4 LT |
70 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
71 | br_forward_finish); | |
72 | } | |
73 | ||
74 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
75 | { | |
76 | struct net_device *indev; | |
77 | ||
4906f998 HX |
78 | if (skb_warn_if_lro(skb)) { |
79 | kfree_skb(skb); | |
80 | return; | |
81 | } | |
82 | ||
1da177e4 LT |
83 | indev = skb->dev; |
84 | skb->dev = to->dev; | |
35fc92a9 | 85 | skb_forward_csum(skb); |
1da177e4 LT |
86 | |
87 | NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev, | |
88 | br_forward_finish); | |
89 | } | |
90 | ||
91 | /* called with rcu_read_lock */ | |
92 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
93 | { | |
94 | if (should_deliver(to, skb)) { | |
95 | __br_deliver(to, skb); | |
96 | return; | |
97 | } | |
98 | ||
99 | kfree_skb(skb); | |
100 | } | |
101 | ||
102 | /* called with rcu_read_lock */ | |
7f7708f0 | 103 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb, struct sk_buff *skb0) |
1da177e4 | 104 | { |
4906f998 | 105 | if (should_deliver(to, skb)) { |
7f7708f0 MB |
106 | if (skb0) |
107 | deliver_clone(to, skb, __br_forward); | |
108 | else | |
109 | __br_forward(to, skb); | |
1da177e4 LT |
110 | return; |
111 | } | |
112 | ||
7f7708f0 MB |
113 | if (!skb0) |
114 | kfree_skb(skb); | |
1da177e4 LT |
115 | } |
116 | ||
87faf3cc DM |
117 | static int deliver_clone(const struct net_bridge_port *prev, |
118 | struct sk_buff *skb, | |
025d89c2 HX |
119 | void (*__packet_hook)(const struct net_bridge_port *p, |
120 | struct sk_buff *skb)) | |
121 | { | |
122 | skb = skb_clone(skb, GFP_ATOMIC); | |
123 | if (!skb) { | |
124 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
125 | ||
126 | dev->stats.tx_dropped++; | |
127 | return -ENOMEM; | |
128 | } | |
129 | ||
130 | __packet_hook(prev, skb); | |
131 | return 0; | |
132 | } | |
133 | ||
134 | static struct net_bridge_port *maybe_deliver( | |
135 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
136 | struct sk_buff *skb, | |
137 | void (*__packet_hook)(const struct net_bridge_port *p, | |
138 | struct sk_buff *skb)) | |
139 | { | |
140 | int err; | |
141 | ||
142 | if (!should_deliver(p, skb)) | |
143 | return prev; | |
144 | ||
145 | if (!prev) | |
146 | goto out; | |
147 | ||
148 | err = deliver_clone(prev, skb, __packet_hook); | |
149 | if (err) | |
150 | return ERR_PTR(err); | |
151 | ||
152 | out: | |
153 | return p; | |
154 | } | |
155 | ||
1da177e4 | 156 | /* called under bridge lock */ |
e081e1e3 | 157 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
b33084be HX |
158 | struct sk_buff *skb0, |
159 | void (*__packet_hook)(const struct net_bridge_port *p, | |
160 | struct sk_buff *skb)) | |
1da177e4 LT |
161 | { |
162 | struct net_bridge_port *p; | |
163 | struct net_bridge_port *prev; | |
164 | ||
1da177e4 LT |
165 | prev = NULL; |
166 | ||
167 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
025d89c2 HX |
168 | prev = maybe_deliver(prev, p, skb, __packet_hook); |
169 | if (IS_ERR(prev)) | |
170 | goto out; | |
1da177e4 LT |
171 | } |
172 | ||
b33084be HX |
173 | if (!prev) |
174 | goto out; | |
175 | ||
025d89c2 HX |
176 | if (skb0) |
177 | deliver_clone(prev, skb, __packet_hook); | |
178 | else | |
179 | __packet_hook(prev, skb); | |
b33084be | 180 | return; |
1da177e4 | 181 | |
b33084be HX |
182 | out: |
183 | if (!skb0) | |
184 | kfree_skb(skb); | |
1da177e4 LT |
185 | } |
186 | ||
187 | ||
188 | /* called with rcu_read_lock */ | |
e081e1e3 | 189 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 190 | { |
b33084be | 191 | br_flood(br, skb, NULL, __br_deliver); |
1da177e4 LT |
192 | } |
193 | ||
194 | /* called under bridge lock */ | |
b33084be HX |
195 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, |
196 | struct sk_buff *skb2) | |
1da177e4 | 197 | { |
b33084be | 198 | br_flood(br, skb, skb2, __br_forward); |
1da177e4 | 199 | } |
5cb5e947 HX |
200 | |
201 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING | |
202 | /* called with rcu_read_lock */ | |
203 | static void br_multicast_flood(struct net_bridge_mdb_entry *mdst, | |
204 | struct sk_buff *skb, struct sk_buff *skb0, | |
205 | void (*__packet_hook)( | |
206 | const struct net_bridge_port *p, | |
207 | struct sk_buff *skb)) | |
208 | { | |
209 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
210 | struct net_bridge *br = netdev_priv(dev); | |
211 | struct net_bridge_port *port; | |
212 | struct net_bridge_port *lport, *rport; | |
213 | struct net_bridge_port *prev; | |
214 | struct net_bridge_port_group *p; | |
215 | struct hlist_node *rp; | |
216 | ||
217 | prev = NULL; | |
218 | ||
168d40ee | 219 | rp = rcu_dereference(br->router_list.first); |
83f6a740 | 220 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 HX |
221 | while (p || rp) { |
222 | lport = p ? p->port : NULL; | |
223 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
224 | NULL; | |
225 | ||
226 | port = (unsigned long)lport > (unsigned long)rport ? | |
227 | lport : rport; | |
228 | ||
229 | prev = maybe_deliver(prev, port, skb, __packet_hook); | |
230 | if (IS_ERR(prev)) | |
231 | goto out; | |
232 | ||
233 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 234 | p = rcu_dereference(p->next); |
5cb5e947 | 235 | if ((unsigned long)rport >= (unsigned long)port) |
168d40ee | 236 | rp = rcu_dereference(rp->next); |
5cb5e947 HX |
237 | } |
238 | ||
239 | if (!prev) | |
240 | goto out; | |
241 | ||
242 | if (skb0) | |
243 | deliver_clone(prev, skb, __packet_hook); | |
244 | else | |
245 | __packet_hook(prev, skb); | |
246 | return; | |
247 | ||
248 | out: | |
249 | if (!skb0) | |
250 | kfree_skb(skb); | |
251 | } | |
252 | ||
253 | /* called with rcu_read_lock */ | |
254 | void br_multicast_deliver(struct net_bridge_mdb_entry *mdst, | |
255 | struct sk_buff *skb) | |
256 | { | |
257 | br_multicast_flood(mdst, skb, NULL, __br_deliver); | |
258 | } | |
259 | ||
260 | /* called with rcu_read_lock */ | |
261 | void br_multicast_forward(struct net_bridge_mdb_entry *mdst, | |
262 | struct sk_buff *skb, struct sk_buff *skb2) | |
263 | { | |
264 | br_multicast_flood(mdst, skb, skb2, __br_forward); | |
265 | } | |
266 | #endif |