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) && |
6bc506b4 IS |
32 | br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING && |
33 | nbp_switchdev_allowed_egress(p, skb); | |
1da177e4 LT |
34 | } |
35 | ||
0c4b51f0 | 36 | int br_dev_queue_push_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 37 | { |
df356d5e TM |
38 | if (!is_skb_forwardable(skb->dev, skb)) |
39 | goto drop; | |
40 | ||
41 | skb_push(skb, ETH_HLEN); | |
42 | br_drop_fake_rtable(skb); | |
df356d5e TM |
43 | |
44 | if (skb->ip_summed == CHECKSUM_PARTIAL && | |
45 | (skb->protocol == htons(ETH_P_8021Q) || | |
46 | skb->protocol == htons(ETH_P_8021AD))) { | |
47 | int depth; | |
48 | ||
49 | if (!__vlan_get_protocol(skb, skb->protocol, &depth)) | |
50 | goto drop; | |
51 | ||
52 | skb_set_network_header(skb, depth); | |
1da177e4 LT |
53 | } |
54 | ||
df356d5e TM |
55 | dev_queue_xmit(skb); |
56 | ||
57 | return 0; | |
58 | ||
59 | drop: | |
60 | kfree_skb(skb); | |
1da177e4 LT |
61 | return 0; |
62 | } | |
34666d46 | 63 | EXPORT_SYMBOL_GPL(br_dev_queue_push_xmit); |
1da177e4 | 64 | |
0c4b51f0 | 65 | int br_forward_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 66 | { |
29a26a56 EB |
67 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_POST_ROUTING, |
68 | net, sk, skb, NULL, skb->dev, | |
9ef513be | 69 | br_dev_queue_push_xmit); |
1da177e4 | 70 | |
1da177e4 | 71 | } |
34666d46 | 72 | EXPORT_SYMBOL_GPL(br_forward_finish); |
1da177e4 | 73 | |
37b090e6 NA |
74 | static void __br_forward(const struct net_bridge_port *to, |
75 | struct sk_buff *skb, bool local_orig) | |
1da177e4 | 76 | { |
2594e906 | 77 | struct net_bridge_vlan_group *vg; |
37b090e6 NA |
78 | struct net_device *indev; |
79 | struct net *net; | |
80 | int br_hook; | |
2594e906 | 81 | |
907b1e6e | 82 | vg = nbp_vlan_group_rcu(to); |
11538d03 | 83 | skb = br_handle_vlan(to->br, to, vg, skb); |
78851988 VY |
84 | if (!skb) |
85 | return; | |
86 | ||
37b090e6 | 87 | indev = skb->dev; |
1da177e4 | 88 | skb->dev = to->dev; |
37b090e6 NA |
89 | if (!local_orig) { |
90 | if (skb_warn_if_lro(skb)) { | |
91d2c34a | 91 | kfree_skb(skb); |
37b090e6 | 92 | return; |
91d2c34a | 93 | } |
37b090e6 NA |
94 | br_hook = NF_BR_FORWARD; |
95 | skb_forward_csum(skb); | |
96 | net = dev_net(indev); | |
97 | } else { | |
98 | if (unlikely(netpoll_tx_running(to->br->dev))) { | |
99 | if (!is_skb_forwardable(skb->dev, skb)) { | |
100 | kfree_skb(skb); | |
101 | } else { | |
102 | skb_push(skb, ETH_HLEN); | |
103 | br_netpoll_send_skb(to, skb); | |
104 | } | |
105 | return; | |
106 | } | |
107 | br_hook = NF_BR_LOCAL_OUT; | |
108 | net = dev_net(skb->dev); | |
109 | indev = NULL; | |
91d2c34a HX |
110 | } |
111 | ||
37b090e6 NA |
112 | NF_HOOK(NFPROTO_BRIDGE, br_hook, |
113 | net, NULL, skb, indev, skb->dev, | |
713aefa3 | 114 | br_forward_finish); |
1da177e4 LT |
115 | } |
116 | ||
37b090e6 NA |
117 | static int deliver_clone(const struct net_bridge_port *prev, |
118 | struct sk_buff *skb, bool local_orig) | |
1da177e4 | 119 | { |
37b090e6 | 120 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; |
1da177e4 | 121 | |
37b090e6 NA |
122 | skb = skb_clone(skb, GFP_ATOMIC); |
123 | if (!skb) { | |
124 | dev->stats.tx_dropped++; | |
125 | return -ENOMEM; | |
1da177e4 LT |
126 | } |
127 | ||
37b090e6 NA |
128 | __br_forward(prev, skb, local_orig); |
129 | return 0; | |
1da177e4 LT |
130 | } |
131 | ||
37b090e6 NA |
132 | /** |
133 | * br_forward - forward a packet to a specific port | |
134 | * @to: destination port | |
135 | * @skb: packet being forwarded | |
136 | * @local_rcv: packet will be received locally after forwarding | |
137 | * @local_orig: packet is locally originated | |
138 | * | |
139 | * Should be called with rcu_read_lock. | |
140 | */ | |
141 | void br_forward(const struct net_bridge_port *to, | |
142 | struct sk_buff *skb, bool local_rcv, bool local_orig) | |
1da177e4 | 143 | { |
b7af1472 | 144 | if (to && should_deliver(to, skb)) { |
b35c5f63 | 145 | if (local_rcv) |
37b090e6 | 146 | deliver_clone(to, skb, local_orig); |
7f7708f0 | 147 | else |
37b090e6 | 148 | __br_forward(to, skb, local_orig); |
1da177e4 LT |
149 | return; |
150 | } | |
151 | ||
b35c5f63 | 152 | if (!local_rcv) |
7f7708f0 | 153 | kfree_skb(skb); |
1da177e4 | 154 | } |
37b090e6 | 155 | EXPORT_SYMBOL_GPL(br_forward); |
025d89c2 HX |
156 | |
157 | static struct net_bridge_port *maybe_deliver( | |
158 | struct net_bridge_port *prev, struct net_bridge_port *p, | |
37b090e6 | 159 | struct sk_buff *skb, bool local_orig) |
025d89c2 HX |
160 | { |
161 | int err; | |
162 | ||
163 | if (!should_deliver(p, skb)) | |
164 | return prev; | |
165 | ||
166 | if (!prev) | |
167 | goto out; | |
168 | ||
37b090e6 | 169 | err = deliver_clone(prev, skb, local_orig); |
025d89c2 HX |
170 | if (err) |
171 | return ERR_PTR(err); | |
172 | ||
173 | out: | |
174 | return p; | |
175 | } | |
176 | ||
37b090e6 NA |
177 | /* called under rcu_read_lock */ |
178 | void br_flood(struct net_bridge *br, struct sk_buff *skb, | |
8addd5e7 | 179 | enum br_pkt_type pkt_type, bool local_rcv, bool local_orig) |
1da177e4 | 180 | { |
1080ab95 | 181 | u8 igmp_type = br_multicast_igmp_type(skb); |
37b090e6 | 182 | struct net_bridge_port *prev = NULL; |
1080ab95 | 183 | struct net_bridge_port *p; |
1da177e4 | 184 | |
1da177e4 | 185 | list_for_each_entry_rcu(p, &br->port_list, list) { |
99f906e9 MM |
186 | /* Do not flood unicast traffic to ports that turn it off, nor |
187 | * other traffic if flood off, except for traffic we originate | |
188 | */ | |
189 | switch (pkt_type) { | |
190 | case BR_PKT_UNICAST: | |
191 | if (!(p->flags & BR_FLOOD)) | |
192 | continue; | |
193 | break; | |
194 | case BR_PKT_MULTICAST: | |
195 | if (!(p->flags & BR_MCAST_FLOOD) && skb->dev != br->dev) | |
196 | continue; | |
197 | break; | |
198 | case BR_PKT_BROADCAST: | |
199 | if (!(p->flags & BR_BCAST_FLOOD) && skb->dev != br->dev) | |
200 | continue; | |
201 | break; | |
202 | } | |
95850116 KP |
203 | |
204 | /* Do not flood to ports that enable proxy ARP */ | |
205 | if (p->flags & BR_PROXYARP) | |
206 | continue; | |
842a9ae0 JM |
207 | if ((p->flags & BR_PROXYARP_WIFI) && |
208 | BR_INPUT_SKB_CB(skb)->proxyarp_replied) | |
209 | continue; | |
95850116 | 210 | |
37b090e6 | 211 | prev = maybe_deliver(prev, p, skb, local_orig); |
025d89c2 HX |
212 | if (IS_ERR(prev)) |
213 | goto out; | |
1080ab95 | 214 | if (prev == p) |
a65056ec | 215 | br_multicast_count(p->br, p, skb, igmp_type, |
1080ab95 | 216 | BR_MCAST_DIR_TX); |
1da177e4 LT |
217 | } |
218 | ||
b33084be HX |
219 | if (!prev) |
220 | goto out; | |
221 | ||
b35c5f63 | 222 | if (local_rcv) |
37b090e6 | 223 | deliver_clone(prev, skb, local_orig); |
025d89c2 | 224 | else |
37b090e6 | 225 | __br_forward(prev, skb, local_orig); |
b33084be | 226 | return; |
1da177e4 | 227 | |
b33084be | 228 | out: |
b35c5f63 | 229 | if (!local_rcv) |
b33084be | 230 | kfree_skb(skb); |
1da177e4 LT |
231 | } |
232 | ||
5cb5e947 | 233 | #ifdef CONFIG_BRIDGE_IGMP_SNOOPING |
5b9d6b15 AB |
234 | static void maybe_deliver_addr(struct net_bridge_port *p, struct sk_buff *skb, |
235 | const unsigned char *addr, bool local_orig) | |
236 | { | |
237 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
238 | const unsigned char *src = eth_hdr(skb)->h_source; | |
239 | ||
240 | if (!should_deliver(p, skb)) | |
241 | return; | |
242 | ||
243 | /* Even with hairpin, no soliloquies - prevent breaking IPv6 DAD */ | |
244 | if (skb->dev == p->dev && ether_addr_equal(src, addr)) | |
245 | return; | |
246 | ||
247 | skb = skb_copy(skb, GFP_ATOMIC); | |
248 | if (!skb) { | |
249 | dev->stats.tx_dropped++; | |
250 | return; | |
251 | } | |
252 | ||
253 | if (!is_broadcast_ether_addr(addr)) | |
254 | memcpy(eth_hdr(skb)->h_dest, addr, ETH_ALEN); | |
255 | ||
256 | __br_forward(p, skb, local_orig); | |
257 | } | |
258 | ||
5cb5e947 | 259 | /* called with rcu_read_lock */ |
37b090e6 NA |
260 | void br_multicast_flood(struct net_bridge_mdb_entry *mdst, |
261 | struct sk_buff *skb, | |
262 | bool local_rcv, bool local_orig) | |
5cb5e947 HX |
263 | { |
264 | struct net_device *dev = BR_INPUT_SKB_CB(skb)->brdev; | |
1080ab95 | 265 | u8 igmp_type = br_multicast_igmp_type(skb); |
5cb5e947 | 266 | struct net_bridge *br = netdev_priv(dev); |
afe0159d | 267 | struct net_bridge_port *prev = NULL; |
5cb5e947 HX |
268 | struct net_bridge_port_group *p; |
269 | struct hlist_node *rp; | |
270 | ||
e8051688 | 271 | rp = rcu_dereference(hlist_first_rcu(&br->router_list)); |
83f6a740 | 272 | p = mdst ? rcu_dereference(mdst->ports) : NULL; |
5cb5e947 | 273 | while (p || rp) { |
afe0159d | 274 | struct net_bridge_port *port, *lport, *rport; |
275 | ||
5cb5e947 HX |
276 | lport = p ? p->port : NULL; |
277 | rport = rp ? hlist_entry(rp, struct net_bridge_port, rlist) : | |
278 | NULL; | |
279 | ||
6db6f0ea FF |
280 | if ((unsigned long)lport > (unsigned long)rport) { |
281 | port = lport; | |
282 | ||
283 | if (port->flags & BR_MULTICAST_TO_UNICAST) { | |
284 | maybe_deliver_addr(lport, skb, p->eth_addr, | |
285 | local_orig); | |
286 | goto delivered; | |
287 | } | |
288 | } else { | |
289 | port = rport; | |
290 | } | |
5cb5e947 | 291 | |
37b090e6 | 292 | prev = maybe_deliver(prev, port, skb, local_orig); |
6db6f0ea | 293 | delivered: |
5cb5e947 HX |
294 | if (IS_ERR(prev)) |
295 | goto out; | |
1080ab95 | 296 | if (prev == port) |
a65056ec | 297 | br_multicast_count(port->br, port, skb, igmp_type, |
1080ab95 | 298 | BR_MCAST_DIR_TX); |
5cb5e947 HX |
299 | |
300 | if ((unsigned long)lport >= (unsigned long)port) | |
83f6a740 | 301 | p = rcu_dereference(p->next); |
5cb5e947 | 302 | if ((unsigned long)rport >= (unsigned long)port) |
e8051688 | 303 | rp = rcu_dereference(hlist_next_rcu(rp)); |
5cb5e947 HX |
304 | } |
305 | ||
306 | if (!prev) | |
307 | goto out; | |
308 | ||
b35c5f63 | 309 | if (local_rcv) |
37b090e6 | 310 | deliver_clone(prev, skb, local_orig); |
5cb5e947 | 311 | else |
37b090e6 | 312 | __br_forward(prev, skb, local_orig); |
5cb5e947 HX |
313 | return; |
314 | ||
315 | out: | |
b35c5f63 | 316 | if (!local_rcv) |
5cb5e947 HX |
317 | kfree_skb(skb); |
318 | } | |
5cb5e947 | 319 | #endif |