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 | ||
04eb4489 EB |
29 | static int br_netif_receive_skb(struct sock *sk, struct sk_buff *skb) |
30 | { | |
31 | return netif_receive_skb(skb); | |
32 | } | |
33 | ||
68b7c895 | 34 | static int br_pass_frame_up(struct sk_buff *skb) |
1da177e4 | 35 | { |
68b7c895 | 36 | struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; |
14bb4789 | 37 | struct net_bridge *br = netdev_priv(brdev); |
8f84985f | 38 | struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); |
fc92f745 | 39 | struct net_port_vlans *pv; |
1da177e4 | 40 | |
406818ff | 41 | u64_stats_update_begin(&brstats->syncp); |
14bb4789 | 42 | brstats->rx_packets++; |
43 | brstats->rx_bytes += skb->len; | |
406818ff | 44 | u64_stats_update_end(&brstats->syncp); |
1da177e4 | 45 | |
85f46c6b VY |
46 | /* Bridge is just like any other port. Make sure the |
47 | * packet is allowed except in promisc modue when someone | |
48 | * may be running packet capture. | |
49 | */ | |
fc92f745 | 50 | pv = br_get_vlan_info(br); |
85f46c6b | 51 | if (!(brdev->flags & IFF_PROMISC) && |
fc92f745 | 52 | !br_allowed_egress(br, pv, skb)) { |
85f46c6b VY |
53 | kfree_skb(skb); |
54 | return NET_RX_DROP; | |
55 | } | |
56 | ||
1da177e4 | 57 | indev = skb->dev; |
a339f1c8 | 58 | skb->dev = brdev; |
fc92f745 VY |
59 | skb = br_handle_vlan(br, pv, skb); |
60 | if (!skb) | |
61 | return NET_RX_DROP; | |
1da177e4 | 62 | |
29a26a56 EB |
63 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, |
64 | dev_net(indev), NULL, skb, indev, NULL, | |
04eb4489 | 65 | br_netif_receive_skb); |
1da177e4 LT |
66 | } |
67 | ||
95850116 | 68 | static void br_do_proxy_arp(struct sk_buff *skb, struct net_bridge *br, |
842a9ae0 | 69 | u16 vid, struct net_bridge_port *p) |
95850116 KP |
70 | { |
71 | struct net_device *dev = br->dev; | |
72 | struct neighbour *n; | |
73 | struct arphdr *parp; | |
74 | u8 *arpptr, *sha; | |
75 | __be32 sip, tip; | |
76 | ||
842a9ae0 JM |
77 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = false; |
78 | ||
95850116 KP |
79 | if (dev->flags & IFF_NOARP) |
80 | return; | |
81 | ||
82 | if (!pskb_may_pull(skb, arp_hdr_len(dev))) { | |
83 | dev->stats.tx_dropped++; | |
84 | return; | |
85 | } | |
86 | parp = arp_hdr(skb); | |
87 | ||
88 | if (parp->ar_pro != htons(ETH_P_IP) || | |
89 | parp->ar_op != htons(ARPOP_REQUEST) || | |
90 | parp->ar_hln != dev->addr_len || | |
91 | parp->ar_pln != 4) | |
92 | return; | |
93 | ||
94 | arpptr = (u8 *)parp + sizeof(struct arphdr); | |
95 | sha = arpptr; | |
96 | arpptr += dev->addr_len; /* sha */ | |
97 | memcpy(&sip, arpptr, sizeof(sip)); | |
98 | arpptr += sizeof(sip); | |
99 | arpptr += dev->addr_len; /* tha */ | |
100 | memcpy(&tip, arpptr, sizeof(tip)); | |
101 | ||
102 | if (ipv4_is_loopback(tip) || | |
103 | ipv4_is_multicast(tip)) | |
104 | return; | |
105 | ||
106 | n = neigh_lookup(&arp_tbl, &tip, dev); | |
107 | if (n) { | |
108 | struct net_bridge_fdb_entry *f; | |
109 | ||
110 | if (!(n->nud_state & NUD_VALID)) { | |
111 | neigh_release(n); | |
112 | return; | |
113 | } | |
114 | ||
115 | f = __br_fdb_get(br, n->ha, vid); | |
842a9ae0 JM |
116 | if (f && ((p->flags & BR_PROXYARP) || |
117 | (f->dst && (f->dst->flags & BR_PROXYARP_WIFI)))) { | |
95850116 KP |
118 | arp_send(ARPOP_REPLY, ETH_P_ARP, sip, skb->dev, tip, |
119 | sha, n->ha, sha); | |
842a9ae0 JM |
120 | BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; |
121 | } | |
95850116 KP |
122 | |
123 | neigh_release(n); | |
124 | } | |
125 | } | |
126 | ||
eeaf61d8 | 127 | /* note: already called with rcu_read_lock */ |
7026b1dd | 128 | int br_handle_frame_finish(struct sock *sk, struct sk_buff *skb) |
1da177e4 LT |
129 | { |
130 | const unsigned char *dest = eth_hdr(skb)->h_dest; | |
f350a0a8 | 131 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
b3f1be4b | 132 | struct net_bridge *br; |
1da177e4 | 133 | struct net_bridge_fdb_entry *dst; |
c4fcb78c | 134 | struct net_bridge_mdb_entry *mdst; |
e081e1e3 | 135 | struct sk_buff *skb2; |
867a5943 | 136 | bool unicast = true; |
78851988 | 137 | u16 vid = 0; |
1da177e4 | 138 | |
b3f1be4b SH |
139 | if (!p || p->state == BR_STATE_DISABLED) |
140 | goto drop; | |
141 | ||
78851988 | 142 | if (!br_allowed_ingress(p->br, nbp_get_vlan_info(p), skb, &vid)) |
eb707618 | 143 | goto out; |
a37b85c9 | 144 | |
85967bb4 | 145 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b | 146 | br = p->br; |
9ba18891 | 147 | if (p->flags & BR_LEARNING) |
a5642ab4 | 148 | br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); |
85967bb4 | 149 | |
44661462 | 150 | if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) && |
06499098 | 151 | br_multicast_rcv(br, p, skb, vid)) |
c4fcb78c HX |
152 | goto drop; |
153 | ||
b3f1be4b SH |
154 | if (p->state == BR_STATE_LEARNING) |
155 | goto drop; | |
0e5eabac | 156 | |
68b7c895 HX |
157 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
158 | ||
e081e1e3 HX |
159 | /* The packet skb2 goes to the local host (NULL to skip). */ |
160 | skb2 = NULL; | |
1da177e4 | 161 | |
e081e1e3 HX |
162 | if (br->dev->flags & IFF_PROMISC) |
163 | skb2 = skb; | |
164 | ||
165 | dst = NULL; | |
1da177e4 | 166 | |
842a9ae0 JM |
167 | if (IS_ENABLED(CONFIG_INET) && skb->protocol == htons(ETH_P_ARP)) |
168 | br_do_proxy_arp(skb, br, vid, p); | |
95850116 | 169 | |
842a9ae0 | 170 | if (is_broadcast_ether_addr(dest)) { |
44661462 | 171 | skb2 = skb; |
867a5943 VY |
172 | unicast = false; |
173 | } else if (is_multicast_ether_addr(dest)) { | |
fbca58a2 | 174 | mdst = br_mdb_get(br, skb, vid); |
b00589af | 175 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
cc0fdd80 | 176 | br_multicast_querier_exists(br, eth_hdr(skb))) { |
8a870178 | 177 | if ((mdst && mdst->mglist) || |
c4fcb78c HX |
178 | br_multicast_is_router(br)) |
179 | skb2 = skb; | |
180 | br_multicast_forward(mdst, skb, skb2); | |
181 | skb = NULL; | |
182 | if (!skb2) | |
183 | goto out; | |
184 | } else | |
185 | skb2 = skb; | |
186 | ||
867a5943 | 187 | unicast = false; |
a339f1c8 | 188 | br->dev->stats.multicast++; |
2ba071ec VY |
189 | } else if ((dst = __br_fdb_get(br, dest, vid)) && |
190 | dst->is_local) { | |
e081e1e3 HX |
191 | skb2 = skb; |
192 | /* Do not forward the packet since it's local. */ | |
193 | skb = NULL; | |
1da177e4 LT |
194 | } |
195 | ||
e081e1e3 | 196 | if (skb) { |
7cd8861a | 197 | if (dst) { |
198 | dst->used = jiffies; | |
7f7708f0 | 199 | br_forward(dst->dst, skb, skb2); |
7cd8861a | 200 | } else |
867a5943 | 201 | br_flood_forward(br, skb, skb2, unicast); |
e081e1e3 | 202 | } |
1da177e4 | 203 | |
87557c18 | 204 | if (skb2) |
68b7c895 | 205 | return br_pass_frame_up(skb2); |
87557c18 | 206 | |
1da177e4 LT |
207 | out: |
208 | return 0; | |
b3f1be4b SH |
209 | drop: |
210 | kfree_skb(skb); | |
211 | goto out; | |
1da177e4 | 212 | } |
34666d46 | 213 | EXPORT_SYMBOL_GPL(br_handle_frame_finish); |
1da177e4 | 214 | |
eeaf61d8 | 215 | /* note: already called with rcu_read_lock */ |
7026b1dd | 216 | static int br_handle_local_finish(struct sock *sk, struct sk_buff *skb) |
cf0f02d0 | 217 | { |
f350a0a8 | 218 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
2ba071ec | 219 | u16 vid = 0; |
cf0f02d0 | 220 | |
e0d7968a TM |
221 | /* check if vlan is allowed, to avoid spoofing */ |
222 | if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) | |
a5642ab4 | 223 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); |
cf0f02d0 SH |
224 | return 0; /* process further */ |
225 | } | |
226 | ||
1da177e4 | 227 | /* |
6229e362 | 228 | * Return NULL if skb is handled |
eeaf61d8 | 229 | * note: already called with rcu_read_lock |
1da177e4 | 230 | */ |
8a4eb573 | 231 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 232 | { |
ab95bfe0 | 233 | struct net_bridge_port *p; |
8a4eb573 | 234 | struct sk_buff *skb = *pskb; |
1da177e4 | 235 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 236 | br_should_route_hook_t *rhook; |
1da177e4 | 237 | |
c2368e79 | 238 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 239 | return RX_HANDLER_PASS; |
ab95bfe0 | 240 | |
1da177e4 | 241 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 242 | goto drop; |
1da177e4 | 243 | |
7b995651 HX |
244 | skb = skb_share_check(skb, GFP_ATOMIC); |
245 | if (!skb) | |
8a4eb573 | 246 | return RX_HANDLER_CONSUMED; |
7b995651 | 247 | |
f350a0a8 | 248 | p = br_port_get_rcu(skb->dev); |
ab95bfe0 | 249 | |
46acc460 | 250 | if (unlikely(is_link_local_ether_addr(dest))) { |
f2808d22 TM |
251 | u16 fwd_mask = p->br->group_fwd_mask_required; |
252 | ||
515853cc | 253 | /* |
254 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
255 | * | |
256 | * Assignment Value | |
257 | * Bridge Group Address 01-80-C2-00-00-00 | |
258 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
259 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
260 | * 802.1X PAE address 01-80-C2-00-00-03 | |
261 | * | |
262 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
263 | * | |
264 | * Others reserved for future standardization | |
265 | */ | |
266 | switch (dest[5]) { | |
267 | case 0x00: /* Bridge Group Address */ | |
268 | /* If STP is turned off, | |
269 | then must forward to keep loop detection */ | |
f2808d22 TM |
270 | if (p->br->stp_enabled == BR_NO_STP || |
271 | fwd_mask & (1u << dest[5])) | |
515853cc | 272 | goto forward; |
273 | break; | |
274 | ||
275 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
276 | goto drop; |
277 | ||
515853cc | 278 | default: |
279 | /* Allow selective forwarding for most other protocols */ | |
f2808d22 TM |
280 | fwd_mask |= p->br->group_fwd_mask; |
281 | if (fwd_mask & (1u << dest[5])) | |
515853cc | 282 | goto forward; |
283 | } | |
a598f6ae | 284 | |
515853cc | 285 | /* Deliver packet to local host only */ |
29a26a56 EB |
286 | if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, |
287 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
288 | br_handle_local_finish)) { | |
8a4eb573 JP |
289 | return RX_HANDLER_CONSUMED; /* consumed by filter */ |
290 | } else { | |
291 | *pskb = skb; | |
292 | return RX_HANDLER_PASS; /* continue processing */ | |
293 | } | |
2111f8b9 | 294 | } |
1da177e4 | 295 | |
a598f6ae | 296 | forward: |
467aea0d SH |
297 | switch (p->state) { |
298 | case BR_STATE_FORWARDING: | |
82de382c | 299 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 300 | if (rhook) { |
8a4eb573 JP |
301 | if ((*rhook)(skb)) { |
302 | *pskb = skb; | |
303 | return RX_HANDLER_PASS; | |
304 | } | |
1da177e4 LT |
305 | dest = eth_hdr(skb)->h_dest; |
306 | } | |
467aea0d SH |
307 | /* fall through */ |
308 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 309 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
310 | skb->pkt_type = PACKET_HOST; |
311 | ||
29a26a56 EB |
312 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, |
313 | dev_net(skb->dev), NULL, skb, skb->dev, NULL, | |
1da177e4 | 314 | br_handle_frame_finish); |
467aea0d SH |
315 | break; |
316 | default: | |
317 | drop: | |
318 | kfree_skb(skb); | |
1da177e4 | 319 | } |
8a4eb573 | 320 | return RX_HANDLER_CONSUMED; |
1da177e4 | 321 | } |