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[mirror_ubuntu-bionic-kernel.git] / net / bridge / br_input.c
CommitLineData
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 */
27br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
28EXPORT_SYMBOL(br_should_route_hook);
29
0c4b51f0
EB
30static int
31br_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 37static 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 75int 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
HX
116 BR_INPUT_SKB_CB(skb)->brdev = br->dev;
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) &&
124 br->neigh_suppress_enabled &&
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
176out:
177 return 0;
b3f1be4b
SH
178drop:
179 kfree_skb(skb);
180 goto out;
1da177e4 181}
34666d46 182EXPORT_SYMBOL_GPL(br_handle_frame_finish);
1da177e4 183
56fae404 184static 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
TM
189 /* check if vlan is allowed, to avoid spoofing */
190 if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid))
a5642ab4 191 br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false);
56fae404
IS
192}
193
194/* note: already called with rcu_read_lock */
195static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
196{
197 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
198
199 __br_handle_local_finish(skb);
8626c56c
FW
200
201 BR_INPUT_SKB_CB(skb)->brdev = p->br->dev;
202 br_pass_frame_up(skb);
203 return 0;
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 210rx_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
515853cc 280 /* Deliver packet to local host only */
8626c56c
FW
281 NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev),
282 NULL, skb, skb->dev, NULL, br_handle_local_finish);
283 return RX_HANDLER_CONSUMED;
2111f8b9 284 }
1da177e4 285
a598f6ae 286forward:
467aea0d
SH
287 switch (p->state) {
288 case BR_STATE_FORWARDING:
82de382c 289 rhook = rcu_dereference(br_should_route_hook);
a386f990 290 if (rhook) {
8a4eb573
JP
291 if ((*rhook)(skb)) {
292 *pskb = skb;
293 return RX_HANDLER_PASS;
294 }
1da177e4
LT
295 dest = eth_hdr(skb)->h_dest;
296 }
467aea0d
SH
297 /* fall through */
298 case BR_STATE_LEARNING:
9a7b6ef9 299 if (ether_addr_equal(p->br->dev->dev_addr, dest))
1da177e4
LT
300 skb->pkt_type = PACKET_HOST;
301
29a26a56
EB
302 NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING,
303 dev_net(skb->dev), NULL, skb, skb->dev, NULL,
1da177e4 304 br_handle_frame_finish);
467aea0d
SH
305 break;
306 default:
307drop:
308 kfree_skb(skb);
1da177e4 309 }
8a4eb573 310 return RX_HANDLER_CONSUMED;
1da177e4 311}