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> |
1da177e4 LT |
20 | #include "br_private.h" |
21 | ||
a386f990 ED |
22 | /* Hook for brouter */ |
23 | br_should_route_hook_t __rcu *br_should_route_hook __read_mostly; | |
24 | EXPORT_SYMBOL(br_should_route_hook); | |
25 | ||
68b7c895 | 26 | static int br_pass_frame_up(struct sk_buff *skb) |
1da177e4 | 27 | { |
68b7c895 | 28 | struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev; |
14bb4789 | 29 | struct net_bridge *br = netdev_priv(brdev); |
30 | struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats); | |
1da177e4 | 31 | |
406818ff | 32 | u64_stats_update_begin(&brstats->syncp); |
14bb4789 | 33 | brstats->rx_packets++; |
34 | brstats->rx_bytes += skb->len; | |
406818ff | 35 | u64_stats_update_end(&brstats->syncp); |
1da177e4 LT |
36 | |
37 | indev = skb->dev; | |
a339f1c8 | 38 | skb->dev = brdev; |
1da177e4 | 39 | |
713aefa3 | 40 | return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL, |
68b7c895 | 41 | netif_receive_skb); |
1da177e4 LT |
42 | } |
43 | ||
eeaf61d8 | 44 | /* note: already called with rcu_read_lock */ |
1da177e4 LT |
45 | int br_handle_frame_finish(struct sk_buff *skb) |
46 | { | |
47 | const unsigned char *dest = eth_hdr(skb)->h_dest; | |
f350a0a8 | 48 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
b3f1be4b | 49 | struct net_bridge *br; |
1da177e4 | 50 | struct net_bridge_fdb_entry *dst; |
c4fcb78c | 51 | struct net_bridge_mdb_entry *mdst; |
e081e1e3 | 52 | struct sk_buff *skb2; |
1da177e4 | 53 | |
b3f1be4b SH |
54 | if (!p || p->state == BR_STATE_DISABLED) |
55 | goto drop; | |
56 | ||
85967bb4 | 57 | /* insert into forwarding database after filtering to avoid spoofing */ |
b3f1be4b SH |
58 | br = p->br; |
59 | br_fdb_update(br, p, eth_hdr(skb)->h_source); | |
85967bb4 | 60 | |
44661462 | 61 | if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) && |
c4fcb78c HX |
62 | br_multicast_rcv(br, p, skb)) |
63 | goto drop; | |
64 | ||
b3f1be4b SH |
65 | if (p->state == BR_STATE_LEARNING) |
66 | goto drop; | |
0e5eabac | 67 | |
68b7c895 HX |
68 | BR_INPUT_SKB_CB(skb)->brdev = br->dev; |
69 | ||
e081e1e3 HX |
70 | /* The packet skb2 goes to the local host (NULL to skip). */ |
71 | skb2 = NULL; | |
1da177e4 | 72 | |
e081e1e3 HX |
73 | if (br->dev->flags & IFF_PROMISC) |
74 | skb2 = skb; | |
75 | ||
76 | dst = NULL; | |
1da177e4 | 77 | |
44661462 HX |
78 | if (is_broadcast_ether_addr(dest)) |
79 | skb2 = skb; | |
80 | else if (is_multicast_ether_addr(dest)) { | |
c4fcb78c | 81 | mdst = br_mdb_get(br, skb); |
32dec5dd | 82 | if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) { |
8a870178 | 83 | if ((mdst && mdst->mglist) || |
c4fcb78c HX |
84 | br_multicast_is_router(br)) |
85 | skb2 = skb; | |
86 | br_multicast_forward(mdst, skb, skb2); | |
87 | skb = NULL; | |
88 | if (!skb2) | |
89 | goto out; | |
90 | } else | |
91 | skb2 = skb; | |
92 | ||
a339f1c8 | 93 | br->dev->stats.multicast++; |
e081e1e3 HX |
94 | } else if ((dst = __br_fdb_get(br, dest)) && dst->is_local) { |
95 | skb2 = skb; | |
96 | /* Do not forward the packet since it's local. */ | |
97 | skb = NULL; | |
1da177e4 LT |
98 | } |
99 | ||
e081e1e3 | 100 | if (skb) { |
7cd8861a | 101 | if (dst) { |
102 | dst->used = jiffies; | |
7f7708f0 | 103 | br_forward(dst->dst, skb, skb2); |
7cd8861a | 104 | } else |
b33084be | 105 | br_flood_forward(br, skb, skb2); |
e081e1e3 | 106 | } |
1da177e4 | 107 | |
87557c18 | 108 | if (skb2) |
68b7c895 | 109 | return br_pass_frame_up(skb2); |
87557c18 | 110 | |
1da177e4 LT |
111 | out: |
112 | return 0; | |
b3f1be4b SH |
113 | drop: |
114 | kfree_skb(skb); | |
115 | goto out; | |
1da177e4 LT |
116 | } |
117 | ||
eeaf61d8 | 118 | /* note: already called with rcu_read_lock */ |
cf0f02d0 SH |
119 | static int br_handle_local_finish(struct sk_buff *skb) |
120 | { | |
f350a0a8 | 121 | struct net_bridge_port *p = br_port_get_rcu(skb->dev); |
cf0f02d0 | 122 | |
f350a0a8 | 123 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source); |
cf0f02d0 SH |
124 | return 0; /* process further */ |
125 | } | |
126 | ||
1da177e4 | 127 | /* |
6229e362 | 128 | * Return NULL if skb is handled |
eeaf61d8 | 129 | * note: already called with rcu_read_lock |
1da177e4 | 130 | */ |
8a4eb573 | 131 | rx_handler_result_t br_handle_frame(struct sk_buff **pskb) |
1da177e4 | 132 | { |
ab95bfe0 | 133 | struct net_bridge_port *p; |
8a4eb573 | 134 | struct sk_buff *skb = *pskb; |
1da177e4 | 135 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
a386f990 | 136 | br_should_route_hook_t *rhook; |
1da177e4 | 137 | |
c2368e79 | 138 | if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) |
8a4eb573 | 139 | return RX_HANDLER_PASS; |
ab95bfe0 | 140 | |
1da177e4 | 141 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
467aea0d | 142 | goto drop; |
1da177e4 | 143 | |
7b995651 HX |
144 | skb = skb_share_check(skb, GFP_ATOMIC); |
145 | if (!skb) | |
8a4eb573 | 146 | return RX_HANDLER_CONSUMED; |
7b995651 | 147 | |
f350a0a8 | 148 | p = br_port_get_rcu(skb->dev); |
ab95bfe0 | 149 | |
46acc460 | 150 | if (unlikely(is_link_local_ether_addr(dest))) { |
515853cc | 151 | /* |
152 | * See IEEE 802.1D Table 7-10 Reserved addresses | |
153 | * | |
154 | * Assignment Value | |
155 | * Bridge Group Address 01-80-C2-00-00-00 | |
156 | * (MAC Control) 802.3 01-80-C2-00-00-01 | |
157 | * (Link Aggregation) 802.3 01-80-C2-00-00-02 | |
158 | * 802.1X PAE address 01-80-C2-00-00-03 | |
159 | * | |
160 | * 802.1AB LLDP 01-80-C2-00-00-0E | |
161 | * | |
162 | * Others reserved for future standardization | |
163 | */ | |
164 | switch (dest[5]) { | |
165 | case 0x00: /* Bridge Group Address */ | |
166 | /* If STP is turned off, | |
167 | then must forward to keep loop detection */ | |
168 | if (p->br->stp_enabled == BR_NO_STP) | |
169 | goto forward; | |
170 | break; | |
171 | ||
172 | case 0x01: /* IEEE MAC (Pause) */ | |
2111f8b9 SH |
173 | goto drop; |
174 | ||
515853cc | 175 | default: |
176 | /* Allow selective forwarding for most other protocols */ | |
177 | if (p->br->group_fwd_mask & (1u << dest[5])) | |
178 | goto forward; | |
179 | } | |
a598f6ae | 180 | |
515853cc | 181 | /* Deliver packet to local host only */ |
713aefa3 | 182 | if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, |
8a4eb573 JP |
183 | NULL, br_handle_local_finish)) { |
184 | return RX_HANDLER_CONSUMED; /* consumed by filter */ | |
185 | } else { | |
186 | *pskb = skb; | |
187 | return RX_HANDLER_PASS; /* continue processing */ | |
188 | } | |
2111f8b9 | 189 | } |
1da177e4 | 190 | |
a598f6ae | 191 | forward: |
467aea0d SH |
192 | switch (p->state) { |
193 | case BR_STATE_FORWARDING: | |
82de382c | 194 | rhook = rcu_dereference(br_should_route_hook); |
a386f990 | 195 | if (rhook) { |
8a4eb573 JP |
196 | if ((*rhook)(skb)) { |
197 | *pskb = skb; | |
198 | return RX_HANDLER_PASS; | |
199 | } | |
1da177e4 LT |
200 | dest = eth_hdr(skb)->h_dest; |
201 | } | |
467aea0d SH |
202 | /* fall through */ |
203 | case BR_STATE_LEARNING: | |
9a7b6ef9 | 204 | if (ether_addr_equal(p->br->dev->dev_addr, dest)) |
1da177e4 LT |
205 | skb->pkt_type = PACKET_HOST; |
206 | ||
713aefa3 | 207 | NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
1da177e4 | 208 | br_handle_frame_finish); |
467aea0d SH |
209 | break; |
210 | default: | |
211 | drop: | |
212 | kfree_skb(skb); | |
1da177e4 | 213 | } |
8a4eb573 | 214 | return RX_HANDLER_CONSUMED; |
1da177e4 | 215 | } |