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> | |
95850116 KP |
19 | #include <linux/neighbour.h> |
20 | #include <net/arp.h> | |
bc3b2d7f | 21 | #include <linux/export.h> |
a37b85c9 | 22 | #include <linux/rculist.h> |
1da177e4 | 23 | #include "br_private.h" |
11538d03 | 24 | #include "br_private_tunnel.h" |
1da177e4 | 25 | |
a386f990 ED |
26 | /* Hook for brouter */ |
27 | br_should_route_hook_t __rcu *br_should_route_hook __read_mostly; | |
28 | EXPORT_SYMBOL(br_should_route_hook); | |
29 | ||
0c4b51f0 EB |
30 | static int |
31 | br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb) | |
04eb4489 EB |
32 | { |
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 | ||
95850116 | 73 | static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br, |
842a9ae0 | 74 | u16 vid, struct net_bridge_port *p) |
95850116 KP |
75 | { |
76 | struct net_device *dev = br->dev; | |
77 | struct neighbour *n; | |
78 | struct arphdr *parp; | |
79 | u8 *arpptr, *sha; | |
80 | __be32 sip, tip; | |
81 | ||
842a9ae0 JM |
82 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = false; |
83 | ||
85a3d4a9 NA |
84 | if ((dev->flags & IFF_NOARP) || |
85 | !pskb_may_pull(skb, arp_hdr_len(dev))) | |
95850116 KP |
86 | return; |
87 | ||
95850116 KP |
88 | parp = arp_hdr(skb); |
89 | ||
90 | if (parp->ar_pro != htons(ETH_P_IP) || | |
91 | parp->ar_op != htons(ARPOP_REQUEST) || | |
92 | parp->ar_hln != dev->addr_len || | |
93 | parp->ar_pln != 4) | |
94 | return; | |
95 | ||
96 | arpptr = (u8 *)parp + sizeof(struct arphdr); | |
97 | sha = arpptr; | |
98 | arpptr += dev->addr_len; /* sha */ | |
99 | memcpy(&sip, arpptr, sizeof(sip)); | |
100 | arpptr += sizeof(sip); | |
101 | arpptr += dev->addr_len; /* tha */ | |
102 | memcpy(&tip, arpptr, sizeof(tip)); | |
103 | ||
104 | if (ipv4_is_loopback(tip) || | |
105 | ipv4_is_multicast(tip)) | |
106 | return; | |
107 | ||
108 | n = neigh_lookup(&arp_tbl, &tip, dev); | |
109 | if (n) { | |
110 | struct net_bridge_fdb_entry *f; | |
111 | ||
112 | if (!(n->nud_state & NUD_VALID)) { | |
113 | neigh_release(n); | |
114 | return; | |
115 | } | |
116 | ||
117 | f = __br_fdb_get(br, n->ha, vid); | |
842a9ae0 JM |
118 | if (f && ((p->flags & BR_PROXYARP) || |
119 | (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) { | |
95850116 KP |
120 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip, |
121 | sha, n->ha, sha); | |
842a9ae0 JM |
122 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; |
123 | } | |
95850116 KP |
124 | |
125 | neigh_release(n); | |
126 | } | |
127 | } | |
128 | ||
eeaf61d8 | 129 | /* note: already called with rcu_read_lock */ |
0c4b51f0 | 130 | int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 131 | { |
f350a0a8 | 132 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
46c0772d | 133 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
8addd5e7 | 134 | enum br_pkt_type pkt_type = BR_PKT_UNICAST; |
46c0772d | 135 | struct net_bridge_fdb_entry *dst = NULL; |
c4fcb78c | 136 | struct net_bridge_mdb_entry *mdst; |
8addd5e7 | 137 | bool local_rcv, mcast_hit = false; |
46c0772d | 138 | struct net_bridge *br; |
78851988 | 139 | u16 vid = 0; |
1da177e4 | 140 | |
b3f1be4b SH |
141 | if (!p || p->state == BR_STATE_DISABLED) |
142 | goto drop; | |
143 | ||
907b1e6e | 144 | if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid)) |
eb707618 | 145 | goto out; |
a37b85c9 | 146 | |
6bc506b4 IS |
147 | nbp_switchdev_frame_mark(p, skb); |
148 | ||
85967bb4 | 149 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b | 150 | br = p->br; |
9ba18891 | 151 | if (p->flags & BR_LEARNING) |
a5642ab4 | 152 | br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); |
85967bb4 | 153 | |
8addd5e7 NA |
154 | local_rcv = !!(br->dev->flags & IFF_PROMISC); |
155 | if (is_multicast_ether_addr(dest)) { | |
156 | /* by definition the broadcast is also a multicast address */ | |
157 | if (is_broadcast_ether_addr(dest)) { | |
158 | pkt_type = BR_PKT_BROADCAST; | |
159 | local_rcv = true; | |
160 | } else { | |
161 | pkt_type = BR_PKT_MULTICAST; | |
162 | if (br_multicast_rcv(br, p, skb, vid)) | |
163 | goto drop; | |
164 | } | |
165 | } | |
c4fcb78c | 166 | |
b3f1be4b SH |
167 | if (p->state == BR_STATE_LEARNING) |
168 | goto drop; | |
0e5eabac | 169 | |
68b7c895 HX |
170 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
171 | ||
842a9ae0 JM |
172 | if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP)) |
173 | br_do_proxy_arp(skb, br, vid, p); | |
95850116 | 174 | |
8addd5e7 NA |
175 | switch (pkt_type) { |
176 | case BR_PKT_MULTICAST: | |
fbca58a2 | 177 | mdst = br_mdb_get(br, skb, vid); |
b00589af | 178 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
cc0fdd80 | 179 | br_multicast_querier_exists(br, eth_hdr(skb))) { |
8a870178 | 180 | if ((mdst && mdst->mglist) || |
e151aab9 | 181 | br_multicast_is_router(br)) { |
b35c5f63 | 182 | local_rcv = true; |
e151aab9 NA |
183 | br->dev->stats.multicast++; |
184 | } | |
185 | mcast_hit = true; | |
46c0772d | 186 | } else { |
b35c5f63 | 187 | local_rcv = true; |
e151aab9 | 188 | br->dev->stats.multicast++; |
46c0772d | 189 | } |
8addd5e7 NA |
190 | break; |
191 | case BR_PKT_UNICAST: | |
192 | dst = __br_fdb_get(br, dest, vid); | |
193 | default: | |
194 | break; | |
1da177e4 LT |
195 | } |
196 | ||
e151aab9 | 197 | if (dst) { |
ca6d4480 | 198 | unsigned long now = jiffies; |
199 | ||
8addd5e7 NA |
200 | if (dst->is_local) |
201 | return br_pass_frame_up(skb); | |
202 | ||
ca6d4480 | 203 | if (now != dst->used) |
204 | dst->used = now; | |
37b090e6 | 205 | br_forward(dst->dst, skb, local_rcv, false); |
e151aab9 NA |
206 | } else { |
207 | if (!mcast_hit) | |
8addd5e7 | 208 | br_flood(br, skb, pkt_type, local_rcv, false); |
e151aab9 | 209 | else |
37b090e6 | 210 | br_multicast_flood(mdst, skb, local_rcv, false); |
e081e1e3 | 211 | } |
1da177e4 | 212 | |
b35c5f63 NA |
213 | if (local_rcv) |
214 | return br_pass_frame_up(skb); | |
87557c18 | 215 | |
1da177e4 LT |
216 | out: |
217 | return 0; | |
b3f1be4b SH |
218 | drop: |
219 | kfree_skb(skb); | |
220 | goto out; | |
1da177e4 | 221 | } |
34666d46 | 222 | EXPORT_SYMBOL_GPL(br_handle_frame_finish); |
1da177e4 | 223 | |
56fae404 | 224 | static void __br_handle_local_finish(struct sk_buff *skb) |
cf0f02d0 | 225 | { |
f350a0a8 | 226 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
2ba071ec | 227 | u16 vid = 0; |
cf0f02d0 | 228 | |
e0d7968a TM |
229 | /* check if vlan is allowed, to avoid spoofing */ |
230 | if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) | |
a5642ab4 | 231 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); |
56fae404 IS |
232 | } |
233 | ||
234 | /* note: already called with rcu_read_lock */ | |
235 | static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb) | |
236 | { | |
237 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); | |
238 | ||
239 | __br_handle_local_finish(skb); | |
8626c56c FW |
240 | |
241 | BR_INPUT_SKB_CB(skb)->brdev = p->br->dev; | |
242 | br_pass_frame_up(skb); | |
243 | return 0; | |
cf0f02d0 SH |
244 | } |
245 | ||
1da177e4 | 246 | /* |
6229e362 | 247 | * Return NULL if skb is handled |
eeaf61d8 | 248 | * note: already called with rcu_read_lock |
1da177e4 | 249 | */ |
8a4eb573 | 250 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 251 | { |
ab95bfe0 | 252 | struct net_bridge_port *p; |
8a4eb573 | 253 | struct sk_buff *skb = *pskb; |
1da177e4 | 254 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 255 | br_should_route_hook_t *rhook; |
1da177e4 | 256 | |
c2368e79 | 257 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 258 | return RX_HANDLER_PASS; |
ab95bfe0 | 259 | |
1da177e4 | 260 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 261 | goto drop; |
1da177e4 | 262 | |
7b995651 HX |
263 | skb = skb_share_check(skb, GFP_ATOMIC); |
264 | if (!skb) | |
8a4eb573 | 265 | return RX_HANDLER_CONSUMED; |
7b995651 | 266 | |
f350a0a8 | 267 | p = br_port_get_rcu(skb->dev); |
11538d03 RP |
268 | if (p->flags & BR_VLAN_TUNNEL) { |
269 | if (br_handle_ingress_vlan_tunnel(skb, p, | |
270 | nbp_vlan_group_rcu(p))) | |
271 | goto drop; | |
272 | } | |
ab95bfe0 | 273 | |
46acc460 | 274 | if (unlikely(is_link_local_ether_addr(dest))) { |
f2808d22 TM |
275 | u16 fwd_mask = p->br->group_fwd_mask_required; |
276 | ||
515853cc | 277 | /* |
278 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
279 | * | |
280 | * Assignment Value | |
281 | * Bridge Group Address 01-80-C2-00-00-00 | |
282 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
283 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
284 | * 802.1X PAE address 01-80-C2-00-00-03 | |
285 | * | |
286 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
287 | * | |
288 | * Others reserved for future standardization | |
289 | */ | |
290 | switch (dest[5]) { | |
291 | case 0x00: /* Bridge Group Address */ | |
292 | /* If STP is turned off, | |
293 | then must forward to keep loop detection */ | |
f2808d22 TM |
294 | if (p->br->stp_enabled == BR_NO_STP || |
295 | fwd_mask & (1u << dest[5])) | |
515853cc | 296 | goto forward; |
56fae404 IS |
297 | *pskb = skb; |
298 | __br_handle_local_finish(skb); | |
299 | return RX_HANDLER_PASS; | |
515853cc | 300 | |
301 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
302 | goto drop; |
303 | ||
baedbe55 IS |
304 | case 0x0E: /* 802.1AB LLDP */ |
305 | fwd_mask |= p->br->group_fwd_mask; | |
306 | if (fwd_mask & (1u << dest[5])) | |
307 | goto forward; | |
308 | *pskb = skb; | |
309 | __br_handle_local_finish(skb); | |
310 | return RX_HANDLER_PASS; | |
311 | ||
515853cc | 312 | default: |
313 | /* Allow selective forwarding for most other protocols */ | |
f2808d22 TM |
314 | fwd_mask |= p->br->group_fwd_mask; |
315 | if (fwd_mask & (1u << dest[5])) | |
515853cc | 316 | goto forward; |
317 | } | |
a598f6ae | 318 | |
515853cc | 319 | /* Deliver packet to local host only */ |
8626c56c FW |
320 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev), |
321 | NULL, skb, skb->dev, NULL, br_handle_local_finish); | |
322 | return RX_HANDLER_CONSUMED; | |
2111f8b9 | 323 | } |
1da177e4 | 324 | |
a598f6ae | 325 | forward: |
467aea0d SH |
326 | switch (p->state) { |
327 | case BR_STATE_FORWARDING: | |
82de382c | 328 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 329 | if (rhook) { |
8a4eb573 JP |
330 | if ((*rhook)(skb)) { |
331 | *pskb = skb; | |
332 | return RX_HANDLER_PASS; | |
333 | } | |
1da177e4 LT |
334 | dest = eth_hdr(skb)->h_dest; |
335 | } | |
467aea0d SH |
336 | /* fall through */ |
337 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 338 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
339 | skb->pkt_type = PACKET_HOST; |
340 | ||
29a26a56 EB |
341 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, |
342 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
1da177e4 | 343 | br_handle_frame_finish); |
467aea0d SH |
344 | break; |
345 | default: | |
346 | drop: | |
347 | kfree_skb(skb); | |
1da177e4 | 348 | } |
8a4eb573 | 349 | return RX_HANDLER_CONSUMED; |
1da177e4 | 350 | } |