]>
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 | 32 | { |
a13b2082 | 33 | br_drop_fake_rtable(skb); |
04eb4489 EB |
34 | return netif_receive_skb(skb); |
35 | } | |
36 | ||
68b7c895 | 37 | static int br_pass_frame_up(struct sk_buff *skb) |
1da177e4 | 38 | { |
68b7c895 | 39 | struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; |
14bb4789 | 40 | struct net_bridge *br = netdev_priv(brdev); |
2594e906 | 41 | struct net_bridge_vlan_group *vg; |
8f84985f | 42 | struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); |
1da177e4 | 43 | |
406818ff | 44 | u64_stats_update_begin(&brstats->syncp); |
14bb4789 | 45 | brstats->rx_packets++; |
46 | brstats->rx_bytes += skb->len; | |
406818ff | 47 | u64_stats_update_end(&brstats->syncp); |
1da177e4 | 48 | |
907b1e6e | 49 | vg = br_vlan_group_rcu(br); |
85f46c6b VY |
50 | /* Bridge is just like any other port. Make sure the |
51 | * packet is allowed except in promisc modue when someone | |
52 | * may be running packet capture. | |
53 | */ | |
54 | if (!(brdev->flags & IFF_PROMISC) && | |
2594e906 | 55 | !br_allowed_egress(vg, skb)) { |
85f46c6b VY |
56 | kfree_skb(skb); |
57 | return NET_RX_DROP; | |
58 | } | |
59 | ||
1da177e4 | 60 | indev = skb->dev; |
a339f1c8 | 61 | skb->dev = brdev; |
11538d03 | 62 | skb = br_handle_vlan(br, NULL, vg, skb); |
fc92f745 VY |
63 | if (!skb) |
64 | return NET_RX_DROP; | |
1080ab95 | 65 | /* update the multicast stats if the packet is IGMP/MLD */ |
a65056ec | 66 | br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb), |
1080ab95 | 67 | BR_MCAST_DIR_TX); |
1da177e4 | 68 | |
29a26a56 EB |
69 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, |
70 | dev_net(indev), NULL, skb, indev, NULL, | |
04eb4489 | 71 | br_netif_receive_skb); |
1da177e4 LT |
72 | } |
73 | ||
eeaf61d8 | 74 | /* note: already called with rcu_read_lock */ |
0c4b51f0 | 75 | int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 | 76 | { |
f350a0a8 | 77 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
8addd5e7 | 78 | enum br_pkt_type pkt_type = BR_PKT_UNICAST; |
46c0772d | 79 | struct net_bridge_fdb_entry *dst = NULL; |
c4fcb78c | 80 | struct net_bridge_mdb_entry *mdst; |
8addd5e7 | 81 | bool local_rcv, mcast_hit = false; |
31a4562d | 82 | const unsigned char *dest; |
46c0772d | 83 | struct net_bridge *br; |
78851988 | 84 | u16 vid = 0; |
1da177e4 | 85 | |
b3f1be4b SH |
86 | if (!p || p->state == BR_STATE_DISABLED) |
87 | goto drop; | |
88 | ||
907b1e6e | 89 | if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid)) |
eb707618 | 90 | goto out; |
a37b85c9 | 91 | |
6bc506b4 IS |
92 | nbp_switchdev_frame_mark(p, skb); |
93 | ||
85967bb4 | 94 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b | 95 | br = p->br; |
9ba18891 | 96 | if (p->flags & BR_LEARNING) |
a5642ab4 | 97 | br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); |
85967bb4 | 98 | |
8addd5e7 | 99 | local_rcv = !!(br->dev->flags & IFF_PROMISC); |
31a4562d | 100 | dest = eth_hdr(skb)->h_dest; |
8addd5e7 NA |
101 | if (is_multicast_ether_addr(dest)) { |
102 | /* by definition the broadcast is also a multicast address */ | |
103 | if (is_broadcast_ether_addr(dest)) { | |
104 | pkt_type = BR_PKT_BROADCAST; | |
105 | local_rcv = true; | |
106 | } else { | |
107 | pkt_type = BR_PKT_MULTICAST; | |
108 | if (br_multicast_rcv(br, p, skb, vid)) | |
109 | goto drop; | |
110 | } | |
111 | } | |
c4fcb78c | 112 | |
b3f1be4b SH |
113 | if (p->state == BR_STATE_LEARNING) |
114 | goto drop; | |
0e5eabac | 115 | |
68b7c895 | 116 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
7d850abd | 117 | BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED); |
68b7c895 | 118 | |
057658cb RP |
119 | if (IS_ENABLED(CONFIG_INET) && |
120 | (skb->protocol == htons(ETH_P_ARP) || | |
121 | skb->protocol == htons(ETH_P_RARP))) { | |
122 | br_do_proxy_suppress_arp(skb, br, vid, p); | |
ed842fae RP |
123 | } else if (IS_ENABLED(CONFIG_IPV6) && |
124 | skb->protocol == htons(ETH_P_IPV6) && | |
c69c2cd4 | 125 | br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) && |
ed842fae RP |
126 | pskb_may_pull(skb, sizeof(struct ipv6hdr) + |
127 | sizeof(struct nd_msg)) && | |
128 | ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) { | |
129 | struct nd_msg *msg, _msg; | |
130 | ||
131 | msg = br_is_nd_neigh_msg(skb, &_msg); | |
132 | if (msg) | |
133 | br_do_suppress_nd(skb, br, vid, p, msg); | |
057658cb | 134 | } |
95850116 | 135 | |
8addd5e7 NA |
136 | switch (pkt_type) { |
137 | case BR_PKT_MULTICAST: | |
fbca58a2 | 138 | mdst = br_mdb_get(br, skb, vid); |
b00589af | 139 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
cc0fdd80 | 140 | br_multicast_querier_exists(br, eth_hdr(skb))) { |
ff0fd34e | 141 | if ((mdst && mdst->host_joined) || |
e151aab9 | 142 | br_multicast_is_router(br)) { |
b35c5f63 | 143 | local_rcv = true; |
e151aab9 NA |
144 | br->dev->stats.multicast++; |
145 | } | |
146 | mcast_hit = true; | |
46c0772d | 147 | } else { |
b35c5f63 | 148 | local_rcv = true; |
e151aab9 | 149 | br->dev->stats.multicast++; |
46c0772d | 150 | } |
8addd5e7 NA |
151 | break; |
152 | case BR_PKT_UNICAST: | |
bfd0aeac | 153 | dst = br_fdb_find_rcu(br, dest, vid); |
8addd5e7 NA |
154 | default: |
155 | break; | |
1da177e4 LT |
156 | } |
157 | ||
e151aab9 | 158 | if (dst) { |
ca6d4480 | 159 | unsigned long now = jiffies; |
160 | ||
8addd5e7 NA |
161 | if (dst->is_local) |
162 | return br_pass_frame_up(skb); | |
163 | ||
ca6d4480 | 164 | if (now != dst->used) |
165 | dst->used = now; | |
37b090e6 | 166 | br_forward(dst->dst, skb, local_rcv, false); |
e151aab9 NA |
167 | } else { |
168 | if (!mcast_hit) | |
8addd5e7 | 169 | br_flood(br, skb, pkt_type, local_rcv, false); |
e151aab9 | 170 | else |
37b090e6 | 171 | br_multicast_flood(mdst, skb, local_rcv, false); |
e081e1e3 | 172 | } |
1da177e4 | 173 | |
b35c5f63 NA |
174 | if (local_rcv) |
175 | return br_pass_frame_up(skb); | |
87557c18 | 176 | |
1da177e4 LT |
177 | out: |
178 | return 0; | |
b3f1be4b SH |
179 | drop: |
180 | kfree_skb(skb); | |
181 | goto out; | |
1da177e4 | 182 | } |
34666d46 | 183 | EXPORT_SYMBOL_GPL(br_handle_frame_finish); |
1da177e4 | 184 | |
56fae404 | 185 | static void __br_handle_local_finish(struct sk_buff *skb) |
cf0f02d0 | 186 | { |
f350a0a8 | 187 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
2ba071ec | 188 | u16 vid = 0; |
cf0f02d0 | 189 | |
e0d7968a | 190 | /* check if vlan is allowed, to avoid spoofing */ |
70e4272b NA |
191 | if ((p->flags & BR_LEARNING) && |
192 | !br_opt_get(p->br, BROPT_NO_LL_LEARN) && | |
193 | br_should_learn(p, skb, &vid)) | |
a5642ab4 | 194 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); |
56fae404 IS |
195 | } |
196 | ||
197 | /* note: already called with rcu_read_lock */ | |
198 | static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb) | |
199 | { | |
56fae404 | 200 | __br_handle_local_finish(skb); |
8626c56c | 201 | |
3b2e2904 NA |
202 | /* return 1 to signal the okfn() was called so it's ok to use the skb */ |
203 | return 1; | |
cf0f02d0 SH |
204 | } |
205 | ||
1da177e4 | 206 | /* |
6229e362 | 207 | * Return NULL if skb is handled |
eeaf61d8 | 208 | * note: already called with rcu_read_lock |
1da177e4 | 209 | */ |
8a4eb573 | 210 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 211 | { |
ab95bfe0 | 212 | struct net_bridge_port *p; |
8a4eb573 | 213 | struct sk_buff *skb = *pskb; |
1da177e4 | 214 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 215 | br_should_route_hook_t *rhook; |
1da177e4 | 216 | |
c2368e79 | 217 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 218 | return RX_HANDLER_PASS; |
ab95bfe0 | 219 | |
1da177e4 | 220 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 221 | goto drop; |
1da177e4 | 222 | |
7b995651 HX |
223 | skb = skb_share_check(skb, GFP_ATOMIC); |
224 | if (!skb) | |
8a4eb573 | 225 | return RX_HANDLER_CONSUMED; |
7b995651 | 226 | |
f350a0a8 | 227 | p = br_port_get_rcu(skb->dev); |
11538d03 RP |
228 | if (p->flags & BR_VLAN_TUNNEL) { |
229 | if (br_handle_ingress_vlan_tunnel(skb, p, | |
230 | nbp_vlan_group_rcu(p))) | |
231 | goto drop; | |
232 | } | |
ab95bfe0 | 233 | |
46acc460 | 234 | if (unlikely(is_link_local_ether_addr(dest))) { |
f2808d22 TM |
235 | u16 fwd_mask = p->br->group_fwd_mask_required; |
236 | ||
515853cc | 237 | /* |
238 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
239 | * | |
240 | * Assignment Value | |
241 | * Bridge Group Address 01-80-C2-00-00-00 | |
242 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
243 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
244 | * 802.1X PAE address 01-80-C2-00-00-03 | |
245 | * | |
246 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
247 | * | |
248 | * Others reserved for future standardization | |
249 | */ | |
5af48b59 | 250 | fwd_mask |= p->group_fwd_mask; |
515853cc | 251 | switch (dest[5]) { |
252 | case 0x00: /* Bridge Group Address */ | |
253 | /* If STP is turned off, | |
254 | then must forward to keep loop detection */ | |
f2808d22 TM |
255 | if (p->br->stp_enabled == BR_NO_STP || |
256 | fwd_mask & (1u << dest[5])) | |
515853cc | 257 | goto forward; |
56fae404 IS |
258 | *pskb = skb; |
259 | __br_handle_local_finish(skb); | |
260 | return RX_HANDLER_PASS; | |
515853cc | 261 | |
262 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
263 | goto drop; |
264 | ||
baedbe55 IS |
265 | case 0x0E: /* 802.1AB LLDP */ |
266 | fwd_mask |= p->br->group_fwd_mask; | |
267 | if (fwd_mask & (1u << dest[5])) | |
268 | goto forward; | |
269 | *pskb = skb; | |
270 | __br_handle_local_finish(skb); | |
271 | return RX_HANDLER_PASS; | |
272 | ||
515853cc | 273 | default: |
274 | /* Allow selective forwarding for most other protocols */ | |
f2808d22 TM |
275 | fwd_mask |= p->br->group_fwd_mask; |
276 | if (fwd_mask & (1u << dest[5])) | |
515853cc | 277 | goto forward; |
278 | } | |
a598f6ae | 279 | |
3b2e2904 NA |
280 | /* The else clause should be hit when nf_hook(): |
281 | * - returns < 0 (drop/error) | |
282 | * - returns = 0 (stolen/nf_queue) | |
283 | * Thus return 1 from the okfn() to signal the skb is ok to pass | |
284 | */ | |
285 | if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, | |
286 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
287 | br_handle_local_finish) == 1) { | |
288 | return RX_HANDLER_PASS; | |
289 | } else { | |
290 | return RX_HANDLER_CONSUMED; | |
291 | } | |
2111f8b9 | 292 | } |
1da177e4 | 293 | |
a598f6ae | 294 | forward: |
467aea0d SH |
295 | switch (p->state) { |
296 | case BR_STATE_FORWARDING: | |
82de382c | 297 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 298 | if (rhook) { |
8a4eb573 JP |
299 | if ((*rhook)(skb)) { |
300 | *pskb = skb; | |
301 | return RX_HANDLER_PASS; | |
302 | } | |
1da177e4 LT |
303 | dest = eth_hdr(skb)->h_dest; |
304 | } | |
467aea0d SH |
305 | /* fall through */ |
306 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 307 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
308 | skb->pkt_type = PACKET_HOST; |
309 | ||
29a26a56 EB |
310 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, |
311 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
1da177e4 | 312 | br_handle_frame_finish); |
467aea0d SH |
313 | break; |
314 | default: | |
315 | drop: | |
316 | kfree_skb(skb); | |
1da177e4 | 317 | } |
8a4eb573 | 318 | return RX_HANDLER_CONSUMED; |
1da177e4 | 319 | } |