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 LT |
23 | #include "br_private.h" |
24 | ||
a386f990 ED |
25 | /* Hook for brouter */ |
26 | br_should_route_hook_t __rcu *br_should_route_hook __read_mostly; | |
27 | EXPORT_SYMBOL(br_should_route_hook); | |
28 | ||
0c4b51f0 EB |
29 | static int |
30 | br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb) | |
04eb4489 EB |
31 | { |
32 | return netif_receive_skb(skb); | |
33 | } | |
34 | ||
68b7c895 | 35 | static int br_pass_frame_up(struct sk_buff *skb) |
1da177e4 | 36 | { |
68b7c895 | 37 | struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; |
14bb4789 | 38 | struct net_bridge *br = netdev_priv(brdev); |
2594e906 | 39 | struct net_bridge_vlan_group *vg; |
8f84985f | 40 | struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); |
1da177e4 | 41 | |
406818ff | 42 | u64_stats_update_begin(&brstats->syncp); |
14bb4789 | 43 | brstats->rx_packets++; |
44 | brstats->rx_bytes += skb->len; | |
406818ff | 45 | u64_stats_update_end(&brstats->syncp); |
1da177e4 | 46 | |
907b1e6e | 47 | vg = br_vlan_group_rcu(br); |
85f46c6b VY |
48 | /* Bridge is just like any other port. Make sure the |
49 | * packet is allowed except in promisc modue when someone | |
50 | * may be running packet capture. | |
51 | */ | |
52 | if (!(brdev->flags & IFF_PROMISC) && | |
2594e906 | 53 | !br_allowed_egress(vg, skb)) { |
85f46c6b VY |
54 | kfree_skb(skb); |
55 | return NET_RX_DROP; | |
56 | } | |
57 | ||
1da177e4 | 58 | indev = skb->dev; |
a339f1c8 | 59 | skb->dev = brdev; |
2594e906 | 60 | skb = br_handle_vlan(br, vg, skb); |
fc92f745 VY |
61 | if (!skb) |
62 | return NET_RX_DROP; | |
1080ab95 | 63 | /* update the multicast stats if the packet is IGMP/MLD */ |
a65056ec | 64 | br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb), |
1080ab95 | 65 | BR_MCAST_DIR_TX); |
1da177e4 | 66 | |
29a26a56 EB |
67 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, |
68 | dev_net(indev), NULL, skb, indev, NULL, | |
04eb4489 | 69 | br_netif_receive_skb); |
1da177e4 LT |
70 | } |
71 | ||
95850116 | 72 | static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br, |
842a9ae0 | 73 | u16 vid, struct net_bridge_port *p) |
95850116 KP |
74 | { |
75 | struct net_device *dev = br->dev; | |
76 | struct neighbour *n; | |
77 | struct arphdr *parp; | |
78 | u8 *arpptr, *sha; | |
79 | __be32 sip, tip; | |
80 | ||
842a9ae0 JM |
81 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = false; |
82 | ||
95850116 KP |
83 | if (dev->flags & IFF_NOARP) |
84 | return; | |
85 | ||
86 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) { | |
87 | dev->stats.tx_dropped++; | |
88 | return; | |
89 | } | |
90 | parp = arp_hdr(skb); | |
91 | ||
92 | if (parp->ar_pro != htons(ETH_P_IP) || | |
93 | parp->ar_op != htons(ARPOP_REQUEST) || | |
94 | parp->ar_hln != dev->addr_len || | |
95 | parp->ar_pln != 4) | |
96 | return; | |
97 | ||
98 | arpptr = (u8 *)parp + sizeof(struct arphdr); | |
99 | sha = arpptr; | |
100 | arpptr += dev->addr_len; /* sha */ | |
101 | memcpy(&sip, arpptr, sizeof(sip)); | |
102 | arpptr += sizeof(sip); | |
103 | arpptr += dev->addr_len; /* tha */ | |
104 | memcpy(&tip, arpptr, sizeof(tip)); | |
105 | ||
106 | if (ipv4_is_loopback(tip) || | |
107 | ipv4_is_multicast(tip)) | |
108 | return; | |
109 | ||
110 | n = neigh_lookup(&arp_tbl, &tip, dev); | |
111 | if (n) { | |
112 | struct net_bridge_fdb_entry *f; | |
113 | ||
114 | if (!(n->nud_state & NUD_VALID)) { | |
115 | neigh_release(n); | |
116 | return; | |
117 | } | |
118 | ||
119 | f = __br_fdb_get(br, n->ha, vid); | |
842a9ae0 JM |
120 | if (f && ((p->flags & BR_PROXYARP) || |
121 | (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) { | |
95850116 KP |
122 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip, |
123 | sha, n->ha, sha); | |
842a9ae0 JM |
124 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; |
125 | } | |
95850116 KP |
126 | |
127 | neigh_release(n); | |
128 | } | |
129 | } | |
130 | ||
eeaf61d8 | 131 | /* note: already called with rcu_read_lock */ |
0c4b51f0 | 132 | int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 133 | { |
b35c5f63 | 134 | bool local_rcv = false, mcast_hit = false, unicast = true; |
f350a0a8 | 135 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
46c0772d NA |
136 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
137 | struct net_bridge_fdb_entry *dst = NULL; | |
c4fcb78c | 138 | struct net_bridge_mdb_entry *mdst; |
46c0772d | 139 | struct net_bridge *br; |
78851988 | 140 | u16 vid = 0; |
1da177e4 | 141 | |
b3f1be4b SH |
142 | if (!p || p->state == BR_STATE_DISABLED) |
143 | goto drop; | |
144 | ||
907b1e6e | 145 | if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid)) |
eb707618 | 146 | goto out; |
a37b85c9 | 147 | |
85967bb4 | 148 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b | 149 | br = p->br; |
9ba18891 | 150 | if (p->flags & BR_LEARNING) |
a5642ab4 | 151 | br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); |
85967bb4 | 152 | |
44661462 | 153 | if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) && |
06499098 | 154 | br_multicast_rcv(br, p, skb, vid)) |
c4fcb78c HX |
155 | goto drop; |
156 | ||
b3f1be4b SH |
157 | if (p->state == BR_STATE_LEARNING) |
158 | goto drop; | |
0e5eabac | 159 | |
68b7c895 HX |
160 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
161 | ||
b35c5f63 | 162 | local_rcv = !!(br->dev->flags & IFF_PROMISC); |
e081e1e3 | 163 | |
842a9ae0 JM |
164 | if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP)) |
165 | br_do_proxy_arp(skb, br, vid, p); | |
95850116 | 166 | |
842a9ae0 | 167 | if (is_broadcast_ether_addr(dest)) { |
b35c5f63 | 168 | local_rcv = true; |
867a5943 VY |
169 | unicast = false; |
170 | } else if (is_multicast_ether_addr(dest)) { | |
fbca58a2 | 171 | mdst = br_mdb_get(br, skb, vid); |
b00589af | 172 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
cc0fdd80 | 173 | br_multicast_querier_exists(br, eth_hdr(skb))) { |
8a870178 | 174 | if ((mdst && mdst->mglist) || |
e151aab9 | 175 | br_multicast_is_router(br)) { |
b35c5f63 | 176 | local_rcv = true; |
e151aab9 NA |
177 | br->dev->stats.multicast++; |
178 | } | |
179 | mcast_hit = true; | |
46c0772d | 180 | } else { |
b35c5f63 | 181 | local_rcv = true; |
e151aab9 | 182 | br->dev->stats.multicast++; |
46c0772d | 183 | } |
867a5943 | 184 | unicast = false; |
46c0772d | 185 | } else if ((dst = __br_fdb_get(br, dest, vid)) && dst->is_local) { |
e081e1e3 | 186 | /* Do not forward the packet since it's local. */ |
e151aab9 | 187 | return br_pass_frame_up(skb); |
1da177e4 LT |
188 | } |
189 | ||
e151aab9 NA |
190 | if (dst) { |
191 | dst->used = jiffies; | |
37b090e6 | 192 | br_forward(dst->dst, skb, local_rcv, false); |
e151aab9 NA |
193 | } else { |
194 | if (!mcast_hit) | |
37b090e6 | 195 | br_flood(br, skb, unicast, local_rcv, false); |
e151aab9 | 196 | else |
37b090e6 | 197 | br_multicast_flood(mdst, skb, local_rcv, false); |
e081e1e3 | 198 | } |
1da177e4 | 199 | |
b35c5f63 NA |
200 | if (local_rcv) |
201 | return br_pass_frame_up(skb); | |
87557c18 | 202 | |
1da177e4 LT |
203 | out: |
204 | return 0; | |
b3f1be4b SH |
205 | drop: |
206 | kfree_skb(skb); | |
207 | goto out; | |
1da177e4 | 208 | } |
34666d46 | 209 | EXPORT_SYMBOL_GPL(br_handle_frame_finish); |
1da177e4 | 210 | |
56fae404 | 211 | static void __br_handle_local_finish(struct sk_buff *skb) |
cf0f02d0 | 212 | { |
f350a0a8 | 213 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
2ba071ec | 214 | u16 vid = 0; |
cf0f02d0 | 215 | |
e0d7968a TM |
216 | /* check if vlan is allowed, to avoid spoofing */ |
217 | if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) | |
a5642ab4 | 218 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); |
56fae404 IS |
219 | } |
220 | ||
221 | /* note: already called with rcu_read_lock */ | |
222 | static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb) | |
223 | { | |
224 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); | |
225 | ||
226 | __br_handle_local_finish(skb); | |
8626c56c FW |
227 | |
228 | BR_INPUT_SKB_CB(skb)->brdev = p->br->dev; | |
229 | br_pass_frame_up(skb); | |
230 | return 0; | |
cf0f02d0 SH |
231 | } |
232 | ||
1da177e4 | 233 | /* |
6229e362 | 234 | * Return NULL if skb is handled |
eeaf61d8 | 235 | * note: already called with rcu_read_lock |
1da177e4 | 236 | */ |
8a4eb573 | 237 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 238 | { |
ab95bfe0 | 239 | struct net_bridge_port *p; |
8a4eb573 | 240 | struct sk_buff *skb = *pskb; |
1da177e4 | 241 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 242 | br_should_route_hook_t *rhook; |
1da177e4 | 243 | |
c2368e79 | 244 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 245 | return RX_HANDLER_PASS; |
ab95bfe0 | 246 | |
1da177e4 | 247 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 248 | goto drop; |
1da177e4 | 249 | |
7b995651 HX |
250 | skb = skb_share_check(skb, GFP_ATOMIC); |
251 | if (!skb) | |
8a4eb573 | 252 | return RX_HANDLER_CONSUMED; |
7b995651 | 253 | |
f350a0a8 | 254 | p = br_port_get_rcu(skb->dev); |
ab95bfe0 | 255 | |
46acc460 | 256 | if (unlikely(is_link_local_ether_addr(dest))) { |
f2808d22 TM |
257 | u16 fwd_mask = p->br->group_fwd_mask_required; |
258 | ||
515853cc | 259 | /* |
260 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
261 | * | |
262 | * Assignment Value | |
263 | * Bridge Group Address 01-80-C2-00-00-00 | |
264 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
265 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
266 | * 802.1X PAE address 01-80-C2-00-00-03 | |
267 | * | |
268 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
269 | * | |
270 | * Others reserved for future standardization | |
271 | */ | |
272 | switch (dest[5]) { | |
273 | case 0x00: /* Bridge Group Address */ | |
274 | /* If STP is turned off, | |
275 | then must forward to keep loop detection */ | |
f2808d22 TM |
276 | if (p->br->stp_enabled == BR_NO_STP || |
277 | fwd_mask & (1u << dest[5])) | |
515853cc | 278 | goto forward; |
56fae404 IS |
279 | *pskb = skb; |
280 | __br_handle_local_finish(skb); | |
281 | return RX_HANDLER_PASS; | |
515853cc | 282 | |
283 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
284 | goto drop; |
285 | ||
baedbe55 IS |
286 | case 0x0E: /* 802.1AB LLDP */ |
287 | fwd_mask |= p->br->group_fwd_mask; | |
288 | if (fwd_mask & (1u << dest[5])) | |
289 | goto forward; | |
290 | *pskb = skb; | |
291 | __br_handle_local_finish(skb); | |
292 | return RX_HANDLER_PASS; | |
293 | ||
515853cc | 294 | default: |
295 | /* Allow selective forwarding for most other protocols */ | |
f2808d22 TM |
296 | fwd_mask |= p->br->group_fwd_mask; |
297 | if (fwd_mask & (1u << dest[5])) | |
515853cc | 298 | goto forward; |
299 | } | |
a598f6ae | 300 | |
515853cc | 301 | /* Deliver packet to local host only */ |
8626c56c FW |
302 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev), |
303 | NULL, skb, skb->dev, NULL, br_handle_local_finish); | |
304 | return RX_HANDLER_CONSUMED; | |
2111f8b9 | 305 | } |
1da177e4 | 306 | |
a598f6ae | 307 | forward: |
467aea0d SH |
308 | switch (p->state) { |
309 | case BR_STATE_FORWARDING: | |
82de382c | 310 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 311 | if (rhook) { |
8a4eb573 JP |
312 | if ((*rhook)(skb)) { |
313 | *pskb = skb; | |
314 | return RX_HANDLER_PASS; | |
315 | } | |
1da177e4 LT |
316 | dest = eth_hdr(skb)->h_dest; |
317 | } | |
467aea0d SH |
318 | /* fall through */ |
319 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 320 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
321 | skb->pkt_type = PACKET_HOST; |
322 | ||
29a26a56 EB |
323 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, |
324 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
1da177e4 | 325 | br_handle_frame_finish); |
467aea0d SH |
326 | break; |
327 | default: | |
328 | drop: | |
329 | kfree_skb(skb); | |
1da177e4 | 330 | } |
8a4eb573 | 331 | return RX_HANDLER_CONSUMED; |
1da177e4 | 332 | } |