Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Handle incoming frames | |
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 | ||
5a0e3ad6 | 14 | #include <linux/slab.h> |
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/netdevice.h> | |
17 | #include <linux/etherdevice.h> | |
18 | #include <linux/netfilter_bridge.h> | |
dc2f4189 | 19 | #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE |
971502d7 | 20 | #include <net/netfilter/nf_queue.h> |
dc2f4189 | 21 | #endif |
95850116 KP |
22 | #include <linux/neighbour.h> |
23 | #include <net/arp.h> | |
bc3b2d7f | 24 | #include <linux/export.h> |
a37b85c9 | 25 | #include <linux/rculist.h> |
1da177e4 | 26 | #include "br_private.h" |
11538d03 | 27 | #include "br_private_tunnel.h" |
1da177e4 | 28 | |
0c4b51f0 EB |
29 | static int |
30 | br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb) | |
04eb4489 | 31 | { |
a13b2082 | 32 | br_drop_fake_rtable(skb); |
04eb4489 EB |
33 | return netif_receive_skb(skb); |
34 | } | |
35 | ||
68b7c895 | 36 | static int br_pass_frame_up(struct sk_buff *skb) |
1da177e4 | 37 | { |
68b7c895 | 38 | struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; |
14bb4789 | 39 | struct net_bridge *br = netdev_priv(brdev); |
2594e906 | 40 | struct net_bridge_vlan_group *vg; |
8f84985f | 41 | struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); |
1da177e4 | 42 | |
406818ff | 43 | u64_stats_update_begin(&brstats->syncp); |
14bb4789 | 44 | brstats->rx_packets++; |
45 | brstats->rx_bytes += skb->len; | |
406818ff | 46 | u64_stats_update_end(&brstats->syncp); |
1da177e4 | 47 | |
907b1e6e | 48 | vg = br_vlan_group_rcu(br); |
85f46c6b VY |
49 | /* Bridge is just like any other port. Make sure the |
50 | * packet is allowed except in promisc modue when someone | |
51 | * may be running packet capture. | |
52 | */ | |
53 | if (!(brdev->flags & IFF_PROMISC) && | |
2594e906 | 54 | !br_allowed_egress(vg, skb)) { |
85f46c6b VY |
55 | kfree_skb(skb); |
56 | return NET_RX_DROP; | |
57 | } | |
58 | ||
1da177e4 | 59 | indev = skb->dev; |
a339f1c8 | 60 | skb->dev = brdev; |
11538d03 | 61 | skb = br_handle_vlan(br, NULL, vg, skb); |
fc92f745 VY |
62 | if (!skb) |
63 | return NET_RX_DROP; | |
1080ab95 | 64 | /* update the multicast stats if the packet is IGMP/MLD */ |
a65056ec | 65 | br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb), |
1080ab95 | 66 | BR_MCAST_DIR_TX); |
1da177e4 | 67 | |
29a26a56 EB |
68 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, |
69 | dev_net(indev), NULL, skb, indev, NULL, | |
04eb4489 | 70 | br_netif_receive_skb); |
1da177e4 LT |
71 | } |
72 | ||
eeaf61d8 | 73 | /* note: already called with rcu_read_lock */ |
0c4b51f0 | 74 | int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 75 | { |
f350a0a8 | 76 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
8addd5e7 | 77 | enum br_pkt_type pkt_type = BR_PKT_UNICAST; |
46c0772d | 78 | struct net_bridge_fdb_entry *dst = NULL; |
c4fcb78c | 79 | struct net_bridge_mdb_entry *mdst; |
8addd5e7 | 80 | bool local_rcv, mcast_hit = false; |
31a4562d | 81 | const unsigned char *dest; |
46c0772d | 82 | struct net_bridge *br; |
78851988 | 83 | u16 vid = 0; |
1da177e4 | 84 | |
b3f1be4b SH |
85 | if (!p || p->state == BR_STATE_DISABLED) |
86 | goto drop; | |
87 | ||
907b1e6e | 88 | if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid)) |
eb707618 | 89 | goto out; |
a37b85c9 | 90 | |
6bc506b4 IS |
91 | nbp_switchdev_frame_mark(p, skb); |
92 | ||
85967bb4 | 93 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b | 94 | br = p->br; |
9ba18891 | 95 | if (p->flags & BR_LEARNING) |
a5642ab4 | 96 | br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); |
85967bb4 | 97 | |
8addd5e7 | 98 | local_rcv = !!(br->dev->flags & IFF_PROMISC); |
31a4562d | 99 | dest = eth_hdr(skb)->h_dest; |
8addd5e7 NA |
100 | if (is_multicast_ether_addr(dest)) { |
101 | /* by definition the broadcast is also a multicast address */ | |
102 | if (is_broadcast_ether_addr(dest)) { | |
103 | pkt_type = BR_PKT_BROADCAST; | |
104 | local_rcv = true; | |
105 | } else { | |
106 | pkt_type = BR_PKT_MULTICAST; | |
107 | if (br_multicast_rcv(br, p, skb, vid)) | |
108 | goto drop; | |
109 | } | |
110 | } | |
c4fcb78c | 111 | |
b3f1be4b SH |
112 | if (p->state == BR_STATE_LEARNING) |
113 | goto drop; | |
0e5eabac | 114 | |
68b7c895 | 115 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
7d850abd | 116 | BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED); |
68b7c895 | 117 | |
057658cb RP |
118 | if (IS_ENABLED(CONFIG_INET) && |
119 | (skb->protocol == htons(ETH_P_ARP) || | |
120 | skb->protocol == htons(ETH_P_RARP))) { | |
121 | br_do_proxy_suppress_arp(skb, br, vid, p); | |
ed842fae RP |
122 | } else if (IS_ENABLED(CONFIG_IPV6) && |
123 | skb->protocol == htons(ETH_P_IPV6) && | |
c69c2cd4 | 124 | br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) && |
ed842fae RP |
125 | pskb_may_pull(skb, sizeof(struct ipv6hdr) + |
126 | sizeof(struct nd_msg)) && | |
127 | ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) { | |
128 | struct nd_msg *msg, _msg; | |
129 | ||
130 | msg = br_is_nd_neigh_msg(skb, &_msg); | |
131 | if (msg) | |
132 | br_do_suppress_nd(skb, br, vid, p, msg); | |
057658cb | 133 | } |
95850116 | 134 | |
8addd5e7 NA |
135 | switch (pkt_type) { |
136 | case BR_PKT_MULTICAST: | |
fbca58a2 | 137 | mdst = br_mdb_get(br, skb, vid); |
b00589af | 138 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
cc0fdd80 | 139 | br_multicast_querier_exists(br, eth_hdr(skb))) { |
ff0fd34e | 140 | if ((mdst && mdst->host_joined) || |
e151aab9 | 141 | br_multicast_is_router(br)) { |
b35c5f63 | 142 | local_rcv = true; |
e151aab9 NA |
143 | br->dev->stats.multicast++; |
144 | } | |
145 | mcast_hit = true; | |
46c0772d | 146 | } else { |
b35c5f63 | 147 | local_rcv = true; |
e151aab9 | 148 | br->dev->stats.multicast++; |
46c0772d | 149 | } |
8addd5e7 NA |
150 | break; |
151 | case BR_PKT_UNICAST: | |
bfd0aeac | 152 | dst = br_fdb_find_rcu(br, dest, vid); |
8addd5e7 NA |
153 | default: |
154 | break; | |
1da177e4 LT |
155 | } |
156 | ||
e151aab9 | 157 | if (dst) { |
ca6d4480 | 158 | unsigned long now = jiffies; |
159 | ||
8addd5e7 NA |
160 | if (dst->is_local) |
161 | return br_pass_frame_up(skb); | |
162 | ||
ca6d4480 | 163 | if (now != dst->used) |
164 | dst->used = now; | |
37b090e6 | 165 | br_forward(dst->dst, skb, local_rcv, false); |
e151aab9 NA |
166 | } else { |
167 | if (!mcast_hit) | |
8addd5e7 | 168 | br_flood(br, skb, pkt_type, local_rcv, false); |
e151aab9 | 169 | else |
37b090e6 | 170 | br_multicast_flood(mdst, skb, local_rcv, false); |
e081e1e3 | 171 | } |
1da177e4 | 172 | |
b35c5f63 NA |
173 | if (local_rcv) |
174 | return br_pass_frame_up(skb); | |
87557c18 | 175 | |
1da177e4 LT |
176 | out: |
177 | return 0; | |
b3f1be4b SH |
178 | drop: |
179 | kfree_skb(skb); | |
180 | goto out; | |
1da177e4 | 181 | } |
34666d46 | 182 | EXPORT_SYMBOL_GPL(br_handle_frame_finish); |
1da177e4 | 183 | |
56fae404 | 184 | static void __br_handle_local_finish(struct sk_buff *skb) |
cf0f02d0 | 185 | { |
f350a0a8 | 186 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
2ba071ec | 187 | u16 vid = 0; |
cf0f02d0 | 188 | |
e0d7968a | 189 | /* check if vlan is allowed, to avoid spoofing */ |
70e4272b NA |
190 | if ((p->flags & BR_LEARNING) && |
191 | !br_opt_get(p->br, BROPT_NO_LL_LEARN) && | |
192 | br_should_learn(p, skb, &vid)) | |
a5642ab4 | 193 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); |
56fae404 IS |
194 | } |
195 | ||
196 | /* note: already called with rcu_read_lock */ | |
197 | static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb) | |
198 | { | |
56fae404 | 199 | __br_handle_local_finish(skb); |
8626c56c | 200 | |
3b2e2904 NA |
201 | /* return 1 to signal the okfn() was called so it's ok to use the skb */ |
202 | return 1; | |
cf0f02d0 SH |
203 | } |
204 | ||
971502d7 FW |
205 | static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb) |
206 | { | |
207 | #ifdef CONFIG_NETFILTER_FAMILY_BRIDGE | |
208 | struct nf_hook_entries *e = NULL; | |
209 | struct nf_hook_state state; | |
210 | unsigned int verdict, i; | |
211 | struct net *net; | |
212 | int ret; | |
213 | ||
214 | net = dev_net(skb->dev); | |
215 | #ifdef HAVE_JUMP_LABEL | |
216 | if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING])) | |
217 | goto frame_finish; | |
218 | #endif | |
219 | ||
220 | e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]); | |
221 | if (!e) | |
222 | goto frame_finish; | |
223 | ||
224 | nf_hook_state_init(&state, NF_BR_PRE_ROUTING, | |
225 | NFPROTO_BRIDGE, skb->dev, NULL, NULL, | |
226 | net, br_handle_frame_finish); | |
227 | ||
228 | for (i = 0; i < e->num_hook_entries; i++) { | |
229 | verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state); | |
230 | switch (verdict & NF_VERDICT_MASK) { | |
231 | case NF_ACCEPT: | |
223fd0ad FW |
232 | if (BR_INPUT_SKB_CB(skb)->br_netfilter_broute) { |
233 | *pskb = skb; | |
234 | return RX_HANDLER_PASS; | |
235 | } | |
971502d7 FW |
236 | break; |
237 | case NF_DROP: | |
238 | kfree_skb(skb); | |
239 | return RX_HANDLER_CONSUMED; | |
240 | case NF_QUEUE: | |
241 | ret = nf_queue(skb, &state, e, i, verdict); | |
242 | if (ret == 1) | |
243 | continue; | |
244 | return RX_HANDLER_CONSUMED; | |
245 | default: /* STOLEN */ | |
246 | return RX_HANDLER_CONSUMED; | |
247 | } | |
248 | } | |
249 | frame_finish: | |
250 | net = dev_net(skb->dev); | |
251 | br_handle_frame_finish(net, NULL, skb); | |
252 | #else | |
253 | br_handle_frame_finish(dev_net(skb->dev), NULL, skb); | |
254 | #endif | |
255 | return RX_HANDLER_CONSUMED; | |
256 | } | |
257 | ||
1da177e4 | 258 | /* |
6229e362 | 259 | * Return NULL if skb is handled |
eeaf61d8 | 260 | * note: already called with rcu_read_lock |
1da177e4 | 261 | */ |
8a4eb573 | 262 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 263 | { |
ab95bfe0 | 264 | struct net_bridge_port *p; |
8a4eb573 | 265 | struct sk_buff *skb = *pskb; |
1da177e4 LT |
266 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
267 | ||
c2368e79 | 268 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 269 | return RX_HANDLER_PASS; |
ab95bfe0 | 270 | |
1da177e4 | 271 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 272 | goto drop; |
1da177e4 | 273 | |
7b995651 HX |
274 | skb = skb_share_check(skb, GFP_ATOMIC); |
275 | if (!skb) | |
8a4eb573 | 276 | return RX_HANDLER_CONSUMED; |
7b995651 | 277 | |
f12064d1 FW |
278 | memset(skb->cb, 0, sizeof(struct br_input_skb_cb)); |
279 | ||
f350a0a8 | 280 | p = br_port_get_rcu(skb->dev); |
11538d03 RP |
281 | if (p->flags & BR_VLAN_TUNNEL) { |
282 | if (br_handle_ingress_vlan_tunnel(skb, p, | |
283 | nbp_vlan_group_rcu(p))) | |
284 | goto drop; | |
285 | } | |
ab95bfe0 | 286 | |
46acc460 | 287 | if (unlikely(is_link_local_ether_addr(dest))) { |
f2808d22 TM |
288 | u16 fwd_mask = p->br->group_fwd_mask_required; |
289 | ||
515853cc | 290 | /* |
291 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
292 | * | |
293 | * Assignment Value | |
294 | * Bridge Group Address 01-80-C2-00-00-00 | |
295 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
296 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
297 | * 802.1X PAE address 01-80-C2-00-00-03 | |
298 | * | |
299 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
300 | * | |
301 | * Others reserved for future standardization | |
302 | */ | |
5af48b59 | 303 | fwd_mask |= p->group_fwd_mask; |
515853cc | 304 | switch (dest[5]) { |
305 | case 0x00: /* Bridge Group Address */ | |
306 | /* If STP is turned off, | |
307 | then must forward to keep loop detection */ | |
f2808d22 TM |
308 | if (p->br->stp_enabled == BR_NO_STP || |
309 | fwd_mask & (1u << dest[5])) | |
515853cc | 310 | goto forward; |
56fae404 IS |
311 | *pskb = skb; |
312 | __br_handle_local_finish(skb); | |
313 | return RX_HANDLER_PASS; | |
515853cc | 314 | |
315 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
316 | goto drop; |
317 | ||
baedbe55 IS |
318 | case 0x0E: /* 802.1AB LLDP */ |
319 | fwd_mask |= p->br->group_fwd_mask; | |
320 | if (fwd_mask & (1u << dest[5])) | |
321 | goto forward; | |
322 | *pskb = skb; | |
323 | __br_handle_local_finish(skb); | |
324 | return RX_HANDLER_PASS; | |
325 | ||
515853cc | 326 | default: |
327 | /* Allow selective forwarding for most other protocols */ | |
f2808d22 TM |
328 | fwd_mask |= p->br->group_fwd_mask; |
329 | if (fwd_mask & (1u << dest[5])) | |
515853cc | 330 | goto forward; |
331 | } | |
a598f6ae | 332 | |
3b2e2904 NA |
333 | /* The else clause should be hit when nf_hook(): |
334 | * - returns < 0 (drop/error) | |
335 | * - returns = 0 (stolen/nf_queue) | |
336 | * Thus return 1 from the okfn() to signal the skb is ok to pass | |
337 | */ | |
338 | if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, | |
339 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
340 | br_handle_local_finish) == 1) { | |
341 | return RX_HANDLER_PASS; | |
342 | } else { | |
343 | return RX_HANDLER_CONSUMED; | |
344 | } | |
2111f8b9 | 345 | } |
1da177e4 | 346 | |
a598f6ae | 347 | forward: |
467aea0d SH |
348 | switch (p->state) { |
349 | case BR_STATE_FORWARDING: | |
467aea0d | 350 | case BR_STATE_LEARNING: |
9a7b6ef9 | 351 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
352 | skb->pkt_type = PACKET_HOST; |
353 | ||
971502d7 | 354 | return nf_hook_bridge_pre(skb, pskb); |
467aea0d SH |
355 | default: |
356 | drop: | |
357 | kfree_skb(skb); | |
1da177e4 | 358 | } |
8a4eb573 | 359 | return RX_HANDLER_CONSUMED; |
1da177e4 | 360 | } |