Commit | Line | Data |
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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> | |
bc3b2d7f | 19 | #include <linux/export.h> |
a37b85c9 | 20 | #include <linux/rculist.h> |
1da177e4 LT |
21 | #include "br_private.h" |
22 | ||
a386f990 ED |
23 | /* Hook for brouter */ |
24 | br_should_route_hook_t __rcu *br_should_route_hook __read_mostly; | |
25 | EXPORT_SYMBOL(br_should_route_hook); | |
26 | ||
68b7c895 | 27 | static int br_pass_frame_up(struct sk_buff *skb) |
1da177e4 | 28 | { |
68b7c895 | 29 | struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; |
14bb4789 | 30 | struct net_bridge *br = netdev_priv(brdev); |
8f84985f | 31 | struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); |
fc92f745 | 32 | struct net_port_vlans *pv; |
1da177e4 | 33 | |
406818ff | 34 | u64_stats_update_begin(&brstats->syncp); |
14bb4789 | 35 | brstats->rx_packets++; |
36 | brstats->rx_bytes += skb->len; | |
406818ff | 37 | u64_stats_update_end(&brstats->syncp); |
1da177e4 | 38 | |
85f46c6b VY |
39 | /* Bridge is just like any other port. Make sure the |
40 | * packet is allowed except in promisc modue when someone | |
41 | * may be running packet capture. | |
42 | */ | |
fc92f745 | 43 | pv = br_get_vlan_info(br); |
85f46c6b | 44 | if (!(brdev->flags & IFF_PROMISC) && |
fc92f745 | 45 | !br_allowed_egress(br, pv, skb)) { |
85f46c6b VY |
46 | kfree_skb(skb); |
47 | return NET_RX_DROP; | |
48 | } | |
49 | ||
1da177e4 | 50 | indev = skb->dev; |
a339f1c8 | 51 | skb->dev = brdev; |
fc92f745 VY |
52 | skb = br_handle_vlan(br, pv, skb); |
53 | if (!skb) | |
54 | return NET_RX_DROP; | |
1da177e4 | 55 | |
713aefa3 | 56 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL, |
68b7c895 | 57 | netif_receive_skb); |
1da177e4 LT |
58 | } |
59 | ||
eeaf61d8 | 60 | /* note: already called with rcu_read_lock */ |
1da177e4 LT |
61 | int br_handle_frame_finish(struct sk_buff *skb) |
62 | { | |
63 | const unsigned char *dest = eth_hdr(skb)->h_dest; | |
f350a0a8 | 64 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
b3f1be4b | 65 | struct net_bridge *br; |
1da177e4 | 66 | struct net_bridge_fdb_entry *dst; |
c4fcb78c | 67 | struct net_bridge_mdb_entry *mdst; |
e081e1e3 | 68 | struct sk_buff *skb2; |
867a5943 | 69 | bool unicast = true; |
78851988 | 70 | u16 vid = 0; |
1da177e4 | 71 | |
b3f1be4b SH |
72 | if (!p || p->state == BR_STATE_DISABLED) |
73 | goto drop; | |
74 | ||
78851988 | 75 | if (!br_allowed_ingress(p->br, nbp_get_vlan_info(p), skb, &vid)) |
eb707618 | 76 | goto out; |
a37b85c9 | 77 | |
85967bb4 | 78 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b | 79 | br = p->br; |
9ba18891 | 80 | if (p->flags & BR_LEARNING) |
a5642ab4 | 81 | br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, false); |
85967bb4 | 82 | |
44661462 | 83 | if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) && |
06499098 | 84 | br_multicast_rcv(br, p, skb, vid)) |
c4fcb78c HX |
85 | goto drop; |
86 | ||
b3f1be4b SH |
87 | if (p->state == BR_STATE_LEARNING) |
88 | goto drop; | |
0e5eabac | 89 | |
68b7c895 HX |
90 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
91 | ||
e081e1e3 HX |
92 | /* The packet skb2 goes to the local host (NULL to skip). */ |
93 | skb2 = NULL; | |
1da177e4 | 94 | |
e081e1e3 HX |
95 | if (br->dev->flags & IFF_PROMISC) |
96 | skb2 = skb; | |
97 | ||
98 | dst = NULL; | |
1da177e4 | 99 | |
867a5943 | 100 | if (is_broadcast_ether_addr(dest)) { |
44661462 | 101 | skb2 = skb; |
867a5943 VY |
102 | unicast = false; |
103 | } else if (is_multicast_ether_addr(dest)) { | |
fbca58a2 | 104 | mdst = br_mdb_get(br, skb, vid); |
b00589af | 105 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
cc0fdd80 | 106 | br_multicast_querier_exists(br, eth_hdr(skb))) { |
8a870178 | 107 | if ((mdst && mdst->mglist) || |
c4fcb78c HX |
108 | br_multicast_is_router(br)) |
109 | skb2 = skb; | |
110 | br_multicast_forward(mdst, skb, skb2); | |
111 | skb = NULL; | |
112 | if (!skb2) | |
113 | goto out; | |
114 | } else | |
115 | skb2 = skb; | |
116 | ||
867a5943 | 117 | unicast = false; |
a339f1c8 | 118 | br->dev->stats.multicast++; |
2ba071ec VY |
119 | } else if ((dst = __br_fdb_get(br, dest, vid)) && |
120 | dst->is_local) { | |
e081e1e3 HX |
121 | skb2 = skb; |
122 | /* Do not forward the packet since it's local. */ | |
123 | skb = NULL; | |
1da177e4 LT |
124 | } |
125 | ||
e081e1e3 | 126 | if (skb) { |
7cd8861a | 127 | if (dst) { |
128 | dst->used = jiffies; | |
7f7708f0 | 129 | br_forward(dst->dst, skb, skb2); |
7cd8861a | 130 | } else |
867a5943 | 131 | br_flood_forward(br, skb, skb2, unicast); |
e081e1e3 | 132 | } |
1da177e4 | 133 | |
87557c18 | 134 | if (skb2) |
68b7c895 | 135 | return br_pass_frame_up(skb2); |
87557c18 | 136 | |
1da177e4 LT |
137 | out: |
138 | return 0; | |
b3f1be4b SH |
139 | drop: |
140 | kfree_skb(skb); | |
141 | goto out; | |
1da177e4 LT |
142 | } |
143 | ||
eeaf61d8 | 144 | /* note: already called with rcu_read_lock */ |
cf0f02d0 SH |
145 | static int br_handle_local_finish(struct sk_buff *skb) |
146 | { | |
f350a0a8 | 147 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
2ba071ec | 148 | u16 vid = 0; |
cf0f02d0 | 149 | |
e0d7968a TM |
150 | /* check if vlan is allowed, to avoid spoofing */ |
151 | if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) | |
a5642ab4 | 152 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); |
cf0f02d0 SH |
153 | return 0; /* process further */ |
154 | } | |
155 | ||
1da177e4 | 156 | /* |
6229e362 | 157 | * Return NULL if skb is handled |
eeaf61d8 | 158 | * note: already called with rcu_read_lock |
1da177e4 | 159 | */ |
8a4eb573 | 160 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 161 | { |
ab95bfe0 | 162 | struct net_bridge_port *p; |
8a4eb573 | 163 | struct sk_buff *skb = *pskb; |
1da177e4 | 164 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 165 | br_should_route_hook_t *rhook; |
1da177e4 | 166 | |
c2368e79 | 167 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 168 | return RX_HANDLER_PASS; |
ab95bfe0 | 169 | |
1da177e4 | 170 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 171 | goto drop; |
1da177e4 | 172 | |
7b995651 HX |
173 | skb = skb_share_check(skb, GFP_ATOMIC); |
174 | if (!skb) | |
8a4eb573 | 175 | return RX_HANDLER_CONSUMED; |
7b995651 | 176 | |
f350a0a8 | 177 | p = br_port_get_rcu(skb->dev); |
ab95bfe0 | 178 | |
46acc460 | 179 | if (unlikely(is_link_local_ether_addr(dest))) { |
f2808d22 TM |
180 | u16 fwd_mask = p->br->group_fwd_mask_required; |
181 | ||
515853cc | 182 | /* |
183 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
184 | * | |
185 | * Assignment Value | |
186 | * Bridge Group Address 01-80-C2-00-00-00 | |
187 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
188 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
189 | * 802.1X PAE address 01-80-C2-00-00-03 | |
190 | * | |
191 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
192 | * | |
193 | * Others reserved for future standardization | |
194 | */ | |
195 | switch (dest[5]) { | |
196 | case 0x00: /* Bridge Group Address */ | |
197 | /* If STP is turned off, | |
198 | then must forward to keep loop detection */ | |
f2808d22 TM |
199 | if (p->br->stp_enabled == BR_NO_STP || |
200 | fwd_mask & (1u << dest[5])) | |
515853cc | 201 | goto forward; |
202 | break; | |
203 | ||
204 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
205 | goto drop; |
206 | ||
515853cc | 207 | default: |
208 | /* Allow selective forwarding for most other protocols */ | |
f2808d22 TM |
209 | fwd_mask |= p->br->group_fwd_mask; |
210 | if (fwd_mask & (1u << dest[5])) | |
515853cc | 211 | goto forward; |
212 | } | |
a598f6ae | 213 | |
515853cc | 214 | /* Deliver packet to local host only */ |
713aefa3 | 215 | if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, |
8a4eb573 JP |
216 | NULL, br_handle_local_finish)) { |
217 | return RX_HANDLER_CONSUMED; /* consumed by filter */ | |
218 | } else { | |
219 | *pskb = skb; | |
220 | return RX_HANDLER_PASS; /* continue processing */ | |
221 | } | |
2111f8b9 | 222 | } |
1da177e4 | 223 | |
a598f6ae | 224 | forward: |
467aea0d SH |
225 | switch (p->state) { |
226 | case BR_STATE_FORWARDING: | |
82de382c | 227 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 228 | if (rhook) { |
8a4eb573 JP |
229 | if ((*rhook)(skb)) { |
230 | *pskb = skb; | |
231 | return RX_HANDLER_PASS; | |
232 | } | |
1da177e4 LT |
233 | dest = eth_hdr(skb)->h_dest; |
234 | } | |
467aea0d SH |
235 | /* fall through */ |
236 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 237 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
238 | skb->pkt_type = PACKET_HOST; |
239 | ||
713aefa3 | 240 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 | 241 | br_handle_frame_finish); |
467aea0d SH |
242 | break; |
243 | default: | |
244 | drop: | |
245 | kfree_skb(skb); | |
1da177e4 | 246 | } |
8a4eb573 | 247 | return RX_HANDLER_CONSUMED; |
1da177e4 | 248 | } |