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; | |
1da177e4 | 63 | |
29a26a56 EB |
64 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, |
65 | dev_net(indev), NULL, skb, indev, NULL, | |
04eb4489 | 66 | br_netif_receive_skb); |
1da177e4 LT |
67 | } |
68 | ||
95850116 | 69 | static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br, |
842a9ae0 | 70 | u16 vid, struct net_bridge_port *p) |
95850116 KP |
71 | { |
72 | struct net_device *dev = br->dev; | |
73 | struct neighbour *n; | |
74 | struct arphdr *parp; | |
75 | u8 *arpptr, *sha; | |
76 | __be32 sip, tip; | |
77 | ||
842a9ae0 JM |
78 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = false; |
79 | ||
95850116 KP |
80 | if (dev->flags & IFF_NOARP) |
81 | return; | |
82 | ||
83 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) { | |
84 | dev->stats.tx_dropped++; | |
85 | return; | |
86 | } | |
87 | parp = arp_hdr(skb); | |
88 | ||
89 | if (parp->ar_pro != htons(ETH_P_IP) || | |
90 | parp->ar_op != htons(ARPOP_REQUEST) || | |
91 | parp->ar_hln != dev->addr_len || | |
92 | parp->ar_pln != 4) | |
93 | return; | |
94 | ||
95 | arpptr = (u8 *)parp + sizeof(struct arphdr); | |
96 | sha = arpptr; | |
97 | arpptr += dev->addr_len; /* sha */ | |
98 | memcpy(&sip, arpptr, sizeof(sip)); | |
99 | arpptr += sizeof(sip); | |
100 | arpptr += dev->addr_len; /* tha */ | |
101 | memcpy(&tip, arpptr, sizeof(tip)); | |
102 | ||
103 | if (ipv4_is_loopback(tip) || | |
104 | ipv4_is_multicast(tip)) | |
105 | return; | |
106 | ||
107 | n = neigh_lookup(&arp_tbl, &tip, dev); | |
108 | if (n) { | |
109 | struct net_bridge_fdb_entry *f; | |
110 | ||
111 | if (!(n->nud_state & NUD_VALID)) { | |
112 | neigh_release(n); | |
113 | return; | |
114 | } | |
115 | ||
116 | f = __br_fdb_get(br, n->ha, vid); | |
842a9ae0 JM |
117 | if (f && ((p->flags & BR_PROXYARP) || |
118 | (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) { | |
95850116 KP |
119 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip, |
120 | sha, n->ha, sha); | |
842a9ae0 JM |
121 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; |
122 | } | |
95850116 KP |
123 | |
124 | neigh_release(n); | |
125 | } | |
126 | } | |
127 | ||
eeaf61d8 | 128 | /* note: already called with rcu_read_lock */ |
0c4b51f0 | 129 | int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
130 | { |
131 | const unsigned char *dest = eth_hdr(skb)->h_dest; | |
f350a0a8 | 132 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
b3f1be4b | 133 | struct net_bridge *br; |
1da177e4 | 134 | struct net_bridge_fdb_entry *dst; |
c4fcb78c | 135 | struct net_bridge_mdb_entry *mdst; |
e081e1e3 | 136 | struct sk_buff *skb2; |
867a5943 | 137 | bool unicast = true; |
78851988 | 138 | u16 vid = 0; |
1da177e4 | 139 | |
b3f1be4b SH |
140 | if (!p || p->state == BR_STATE_DISABLED) |
141 | goto drop; | |
142 | ||
907b1e6e | 143 | if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid)) |
eb707618 | 144 | goto out; |
a37b85c9 | 145 | |
85967bb4 | 146 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b | 147 | br = p->br; |
9ba18891 | 148 | if (p->flags & BR_LEARNING) |
a5642ab4 | 149 | br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); |
85967bb4 | 150 | |
44661462 | 151 | if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) && |
06499098 | 152 | br_multicast_rcv(br, p, skb, vid)) |
c4fcb78c HX |
153 | goto drop; |
154 | ||
b3f1be4b SH |
155 | if (p->state == BR_STATE_LEARNING) |
156 | goto drop; | |
0e5eabac | 157 | |
68b7c895 HX |
158 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
159 | ||
e081e1e3 HX |
160 | /* The packet skb2 goes to the local host (NULL to skip). */ |
161 | skb2 = NULL; | |
1da177e4 | 162 | |
e081e1e3 HX |
163 | if (br->dev->flags & IFF_PROMISC) |
164 | skb2 = skb; | |
165 | ||
166 | dst = NULL; | |
1da177e4 | 167 | |
842a9ae0 JM |
168 | if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP)) |
169 | br_do_proxy_arp(skb, br, vid, p); | |
95850116 | 170 | |
842a9ae0 | 171 | if (is_broadcast_ether_addr(dest)) { |
44661462 | 172 | skb2 = skb; |
867a5943 VY |
173 | unicast = false; |
174 | } else if (is_multicast_ether_addr(dest)) { | |
fbca58a2 | 175 | mdst = br_mdb_get(br, skb, vid); |
b00589af | 176 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
cc0fdd80 | 177 | br_multicast_querier_exists(br, eth_hdr(skb))) { |
8a870178 | 178 | if ((mdst && mdst->mglist) || |
c4fcb78c HX |
179 | br_multicast_is_router(br)) |
180 | skb2 = skb; | |
181 | br_multicast_forward(mdst, skb, skb2); | |
182 | skb = NULL; | |
183 | if (!skb2) | |
184 | goto out; | |
185 | } else | |
186 | skb2 = skb; | |
187 | ||
867a5943 | 188 | unicast = false; |
a339f1c8 | 189 | br->dev->stats.multicast++; |
2ba071ec VY |
190 | } else if ((dst = __br_fdb_get(br, dest, vid)) && |
191 | dst->is_local) { | |
e081e1e3 HX |
192 | skb2 = skb; |
193 | /* Do not forward the packet since it's local. */ | |
194 | skb = NULL; | |
1da177e4 LT |
195 | } |
196 | ||
e081e1e3 | 197 | if (skb) { |
7cd8861a | 198 | if (dst) { |
199 | dst->used = jiffies; | |
7f7708f0 | 200 | br_forward(dst->dst, skb, skb2); |
7cd8861a | 201 | } else |
867a5943 | 202 | br_flood_forward(br, skb, skb2, unicast); |
e081e1e3 | 203 | } |
1da177e4 | 204 | |
87557c18 | 205 | if (skb2) |
68b7c895 | 206 | return br_pass_frame_up(skb2); |
87557c18 | 207 | |
1da177e4 LT |
208 | out: |
209 | return 0; | |
b3f1be4b SH |
210 | drop: |
211 | kfree_skb(skb); | |
212 | goto out; | |
1da177e4 | 213 | } |
34666d46 | 214 | EXPORT_SYMBOL_GPL(br_handle_frame_finish); |
1da177e4 | 215 | |
eeaf61d8 | 216 | /* note: already called with rcu_read_lock */ |
0c4b51f0 | 217 | static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb) |
cf0f02d0 | 218 | { |
f350a0a8 | 219 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
2ba071ec | 220 | u16 vid = 0; |
cf0f02d0 | 221 | |
e0d7968a TM |
222 | /* check if vlan is allowed, to avoid spoofing */ |
223 | if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) | |
a5642ab4 | 224 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); |
8626c56c FW |
225 | |
226 | BR_INPUT_SKB_CB(skb)->brdev = p->br->dev; | |
227 | br_pass_frame_up(skb); | |
228 | return 0; | |
cf0f02d0 SH |
229 | } |
230 | ||
1da177e4 | 231 | /* |
6229e362 | 232 | * Return NULL if skb is handled |
eeaf61d8 | 233 | * note: already called with rcu_read_lock |
1da177e4 | 234 | */ |
8a4eb573 | 235 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 236 | { |
ab95bfe0 | 237 | struct net_bridge_port *p; |
8a4eb573 | 238 | struct sk_buff *skb = *pskb; |
1da177e4 | 239 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 240 | br_should_route_hook_t *rhook; |
1da177e4 | 241 | |
c2368e79 | 242 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 243 | return RX_HANDLER_PASS; |
ab95bfe0 | 244 | |
1da177e4 | 245 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 246 | goto drop; |
1da177e4 | 247 | |
7b995651 HX |
248 | skb = skb_share_check(skb, GFP_ATOMIC); |
249 | if (!skb) | |
8a4eb573 | 250 | return RX_HANDLER_CONSUMED; |
7b995651 | 251 | |
f350a0a8 | 252 | p = br_port_get_rcu(skb->dev); |
ab95bfe0 | 253 | |
46acc460 | 254 | if (unlikely(is_link_local_ether_addr(dest))) { |
f2808d22 TM |
255 | u16 fwd_mask = p->br->group_fwd_mask_required; |
256 | ||
515853cc | 257 | /* |
258 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
259 | * | |
260 | * Assignment Value | |
261 | * Bridge Group Address 01-80-C2-00-00-00 | |
262 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
263 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
264 | * 802.1X PAE address 01-80-C2-00-00-03 | |
265 | * | |
266 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
267 | * | |
268 | * Others reserved for future standardization | |
269 | */ | |
270 | switch (dest[5]) { | |
271 | case 0x00: /* Bridge Group Address */ | |
272 | /* If STP is turned off, | |
273 | then must forward to keep loop detection */ | |
f2808d22 TM |
274 | if (p->br->stp_enabled == BR_NO_STP || |
275 | fwd_mask & (1u << dest[5])) | |
515853cc | 276 | goto forward; |
277 | break; | |
278 | ||
279 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
280 | goto drop; |
281 | ||
515853cc | 282 | default: |
283 | /* Allow selective forwarding for most other protocols */ | |
f2808d22 TM |
284 | fwd_mask |= p->br->group_fwd_mask; |
285 | if (fwd_mask & (1u << dest[5])) | |
515853cc | 286 | goto forward; |
287 | } | |
a598f6ae | 288 | |
515853cc | 289 | /* Deliver packet to local host only */ |
8626c56c FW |
290 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev), |
291 | NULL, skb, skb->dev, NULL, br_handle_local_finish); | |
292 | return RX_HANDLER_CONSUMED; | |
2111f8b9 | 293 | } |
1da177e4 | 294 | |
a598f6ae | 295 | forward: |
467aea0d SH |
296 | switch (p->state) { |
297 | case BR_STATE_FORWARDING: | |
82de382c | 298 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 299 | if (rhook) { |
8a4eb573 JP |
300 | if ((*rhook)(skb)) { |
301 | *pskb = skb; | |
302 | return RX_HANDLER_PASS; | |
303 | } | |
1da177e4 LT |
304 | dest = eth_hdr(skb)->h_dest; |
305 | } | |
467aea0d SH |
306 | /* fall through */ |
307 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 308 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
309 | skb->pkt_type = PACKET_HOST; |
310 | ||
29a26a56 EB |
311 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, |
312 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
1da177e4 | 313 | br_handle_frame_finish); |
467aea0d SH |
314 | break; |
315 | default: | |
316 | drop: | |
317 | kfree_skb(skb); | |
1da177e4 | 318 | } |
8a4eb573 | 319 | return RX_HANDLER_CONSUMED; |
1da177e4 | 320 | } |