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 | ||
1a81a2e0 | 24 | /* Don't forward packets to originating port or forwarding disabled */ |
9d6f229f | 25 | static inline int should_deliver(const struct net_bridge_port *p, |
1da177e4 LT |
26 | const struct sk_buff *skb) |
27 | { | |
2594e906 NA |
28 | struct net_bridge_vlan_group *vg; |
29 | ||
907b1e6e | 30 | vg = nbp_vlan_group_rcu(p); |
a97bfc1d | 31 | return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) && |
2594e906 | 32 | br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING; |
1da177e4 LT |
33 | } |
34 | ||
0c4b51f0 | 35 | int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 36 | { |
df356d5e TM |
37 | if (!is_skb_forwardable(skb->dev, skb)) |
38 | goto drop; | |
39 | ||
40 | skb_push(skb, ETH_HLEN); | |
41 | br_drop_fake_rtable(skb); | |
df356d5e TM |
42 | |
43 | if (skb->ip_summed == CHECKSUM_PARTIAL && | |
44 | (skb->protocol == htons(ETH_P_8021Q) || | |
45 | skb->protocol == htons(ETH_P_8021AD))) { | |
46 | int depth; | |
47 | ||
48 | if (!__vlan_get_protocol(skb, skb->protocol, &depth)) | |
49 | goto drop; | |
50 | ||
51 | skb_set_network_header(skb, depth); | |
1da177e4 LT |
52 | } |
53 | ||
df356d5e TM |
54 | dev_queue_xmit(skb); |
55 | ||
56 | return 0; | |
57 | ||
58 | drop: | |
59 | kfree_skb(skb); | |
1da177e4 LT |
60 | return 0; |
61 | } | |
34666d46 | 62 | EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit); |
1da177e4 | 63 | |
0c4b51f0 | 64 | int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 65 | { |
29a26a56 EB |
66 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, |
67 | net, sk, skb, NULL, skb->dev, | |
9ef513be | 68 | br_dev_queue_push_xmit); |
1da177e4 | 69 | |
1da177e4 | 70 | } |
34666d46 | 71 | EXPORT_SYMBOL_GPL(br_forward_finish); |
1da177e4 | 72 | |
37b090e6 NA |
73 | static void __br_forward(const struct net_bridge_port *to, |
74 | struct sk_buff *skb, bool local_orig) | |
1da177e4 | 75 | { |
2594e906 | 76 | struct net_bridge_vlan_group *vg; |
37b090e6 NA |
77 | struct net_device *indev; |
78 | struct net *net; | |
79 | int br_hook; | |
2594e906 | 80 | |
907b1e6e | 81 | vg = nbp_vlan_group_rcu(to); |
2594e906 | 82 | skb = br_handle_vlan(to->br, vg, skb); |
78851988 VY |
83 | if (!skb) |
84 | return; | |
85 | ||
37b090e6 | 86 | indev = skb->dev; |
1da177e4 | 87 | skb->dev = to->dev; |
37b090e6 NA |
88 | if (!local_orig) { |
89 | if (skb_warn_if_lro(skb)) { | |
91d2c34a | 90 | kfree_skb(skb); |
37b090e6 | 91 | return; |
91d2c34a | 92 | } |
37b090e6 NA |
93 | br_hook = NF_BR_FORWARD; |
94 | skb_forward_csum(skb); | |
95 | net = dev_net(indev); | |
96 | } else { | |
97 | if (unlikely(netpoll_tx_running(to->br->dev))) { | |
98 | if (!is_skb_forwardable(skb->dev, skb)) { | |
99 | kfree_skb(skb); | |
100 | } else { | |
101 | skb_push(skb, ETH_HLEN); | |
102 | br_netpoll_send_skb(to, skb); | |
103 | } | |
104 | return; | |
105 | } | |
106 | br_hook = NF_BR_LOCAL_OUT; | |
107 | net = dev_net(skb->dev); | |
108 | indev = NULL; | |
91d2c34a HX |
109 | } |
110 | ||
37b090e6 NA |
111 | NF_HOOK(NFPROTO_BRIDGE, br_hook, |
112 | net, NULL, skb, indev, skb->dev, | |
713aefa3 | 113 | br_forward_finish); |
1da177e4 LT |
114 | } |
115 | ||
37b090e6 NA |
116 | static int deliver_clone(const struct net_bridge_port *prev, |
117 | struct sk_buff *skb, bool local_orig) | |
1da177e4 | 118 | { |
37b090e6 | 119 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
1da177e4 | 120 | |
37b090e6 NA |
121 | skb = skb_clone(skb, GFP_ATOMIC); |
122 | if (!skb) { | |
123 | dev->stats.tx_dropped++; | |
124 | return -ENOMEM; | |
1da177e4 LT |
125 | } |
126 | ||
37b090e6 NA |
127 | __br_forward(prev, skb, local_orig); |
128 | return 0; | |
1da177e4 LT |
129 | } |
130 | ||
37b090e6 NA |
131 | /** |
132 | * br_forward - forward a packet to a specific port | |
133 | * @to: destination port | |
134 | * @skb: packet being forwarded | |
135 | * @local_rcv: packet will be received locally after forwarding | |
136 | * @local_orig: packet is locally originated | |
137 | * | |
138 | * Should be called with rcu_read_lock. | |
139 | */ | |
140 | void br_forward(const struct net_bridge_port *to, | |
141 | struct sk_buff *skb, bool local_rcv, bool local_orig) | |
1da177e4 | 142 | { |
b7af1472 | 143 | if (to && should_deliver(to, skb)) { |
b35c5f63 | 144 | if (local_rcv) |
37b090e6 | 145 | deliver_clone(to, skb, local_orig); |
7f7708f0 | 146 | else |
37b090e6 | 147 | __br_forward(to, skb, local_orig); |
1da177e4 LT |
148 | return; |
149 | } | |
150 | ||
b35c5f63 | 151 | if (!local_rcv) |
7f7708f0 | 152 | kfree_skb(skb); |
1da177e4 | 153 | } |
37b090e6 | 154 | EXPORT_SYMBOL_GPL(br_forward); |
025d89c2 HX |
155 | |
156 | static struct net_bridge_port *maybe_deliver( | |
157 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
37b090e6 | 158 | struct sk_buff *skb, bool local_orig) |
025d89c2 HX |
159 | { |
160 | int err; | |
161 | ||
162 | if (!should_deliver(p, skb)) | |
163 | return prev; | |
164 | ||
165 | if (!prev) | |
166 | goto out; | |
167 | ||
37b090e6 | 168 | err = deliver_clone(prev, skb, local_orig); |
025d89c2 HX |
169 | if (err) |
170 | return ERR_PTR(err); | |
171 | ||
172 | out: | |
173 | return p; | |
174 | } | |
175 | ||
37b090e6 NA |
176 | /* called under rcu_read_lock */ |
177 | void br_flood(struct net_bridge *br, struct sk_buff *skb, | |
178 | bool unicast, bool local_rcv, bool local_orig) | |
1da177e4 | 179 | { |
1080ab95 | 180 | u8 igmp_type = br_multicast_igmp_type(skb); |
37b090e6 | 181 | struct net_bridge_port *prev = NULL; |
1080ab95 | 182 | struct net_bridge_port *p; |
1da177e4 | 183 | |
1da177e4 | 184 | list_for_each_entry_rcu(p, &br->port_list, list) { |
867a5943 VY |
185 | /* Do not flood unicast traffic to ports that turn it off */ |
186 | if (unicast && !(p->flags & BR_FLOOD)) | |
187 | continue; | |
95850116 KP |
188 | |
189 | /* Do not flood to ports that enable proxy ARP */ | |
190 | if (p->flags & BR_PROXYARP) | |
191 | continue; | |
842a9ae0 JM |
192 | if ((p->flags & BR_PROXYARP_WIFI) && |
193 | BR_INPUT_SKB_CB(skb)->proxyarp_replied) | |
194 | continue; | |
95850116 | 195 | |
37b090e6 | 196 | prev = maybe_deliver(prev, p, skb, local_orig); |
025d89c2 HX |
197 | if (IS_ERR(prev)) |
198 | goto out; | |
1080ab95 | 199 | if (prev == p) |
a65056ec | 200 | br_multicast_count(p->br, p, skb, igmp_type, |
1080ab95 | 201 | BR_MCAST_DIR_TX); |
1da177e4 LT |
202 | } |
203 | ||
b33084be HX |
204 | if (!prev) |
205 | goto out; | |
206 | ||
b35c5f63 | 207 | if (local_rcv) |
37b090e6 | 208 | deliver_clone(prev, skb, local_orig); |
025d89c2 | 209 | else |
37b090e6 | 210 | __br_forward(prev, skb, local_orig); |
b33084be | 211 | return; |
1da177e4 | 212 | |
b33084be | 213 | out: |
b35c5f63 | 214 | if (!local_rcv) |
b33084be | 215 | kfree_skb(skb); |
1da177e4 LT |
216 | } |
217 | ||
5cb5e947 HX |
218 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING |
219 | /* called with rcu_read_lock */ | |
37b090e6 NA |
220 | void br_multicast_flood(struct net_bridge_mdb_entry *mdst, |
221 | struct sk_buff *skb, | |
222 | bool local_rcv, bool local_orig) | |
5cb5e947 HX |
223 | { |
224 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
1080ab95 | 225 | u8 igmp_type = br_multicast_igmp_type(skb); |
5cb5e947 | 226 | struct net_bridge *br = netdev_priv(dev); |
afe0159d | 227 | struct net_bridge_port *prev = NULL; |
5cb5e947 HX |
228 | struct net_bridge_port_group *p; |
229 | struct hlist_node *rp; | |
230 | ||
e8051688 | 231 | rp = rcu_dereference(hlist_first_rcu(&br->router_list)); |
83f6a740 | 232 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 | 233 | while (p || rp) { |
afe0159d | 234 | struct net_bridge_port *port, *lport, *rport; |
235 | ||
5cb5e947 HX |
236 | lport = p ? p->port : NULL; |
237 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
238 | NULL; | |
239 | ||
240 | port = (unsigned long)lport > (unsigned long)rport ? | |
241 | lport : rport; | |
242 | ||
37b090e6 | 243 | prev = maybe_deliver(prev, port, skb, local_orig); |
5cb5e947 HX |
244 | if (IS_ERR(prev)) |
245 | goto out; | |
1080ab95 | 246 | if (prev == port) |
a65056ec | 247 | br_multicast_count(port->br, port, skb, igmp_type, |
1080ab95 | 248 | BR_MCAST_DIR_TX); |
5cb5e947 HX |
249 | |
250 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 251 | p = rcu_dereference(p->next); |
5cb5e947 | 252 | if ((unsigned long)rport >= (unsigned long)port) |
e8051688 | 253 | rp = rcu_dereference(hlist_next_rcu(rp)); |
5cb5e947 HX |
254 | } |
255 | ||
256 | if (!prev) | |
257 | goto out; | |
258 | ||
b35c5f63 | 259 | if (local_rcv) |
37b090e6 | 260 | deliver_clone(prev, skb, local_orig); |
5cb5e947 | 261 | else |
37b090e6 | 262 | __br_forward(prev, skb, local_orig); |
5cb5e947 HX |
263 | return; |
264 | ||
265 | out: | |
b35c5f63 | 266 | if (!local_rcv) |
5cb5e947 HX |
267 | kfree_skb(skb); |
268 | } | |
5cb5e947 | 269 | #endif |