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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Handle incoming frames
3 * Linux ethernet bridge
4 *
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * 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
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/netdevice.h>
17#include <linux/etherdevice.h>
18#include <linux/netfilter_bridge.h>
19#include "br_private.h"
20
Stephen Hemmingerfda93d92006-03-20 22:59:21 -080021/* Bridge group multicast address 802.1d (pg 51). */
22const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
Eric Dumazeta386f992010-11-15 06:38:11 +000024/* Hook for brouter */
25br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
26EXPORT_SYMBOL(br_should_route_hook);
27
Herbert Xu68b7c892010-02-27 19:41:40 +000028static int br_pass_frame_up(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029{
Herbert Xu68b7c892010-02-27 19:41:40 +000030 struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
stephen hemminger14bb4782010-03-02 13:32:09 +000031 struct net_bridge *br = netdev_priv(brdev);
32 struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Eric Dumazet406818f2010-06-23 13:00:48 -070034 u64_stats_update_begin(&brstats->syncp);
stephen hemminger14bb4782010-03-02 13:32:09 +000035 brstats->rx_packets++;
36 brstats->rx_bytes += skb->len;
Eric Dumazet406818f2010-06-23 13:00:48 -070037 u64_stats_update_end(&brstats->syncp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39 indev = skb->dev;
Pavel Emelyanova339f1c2008-05-21 14:13:47 -070040 skb->dev = brdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
Jan Engelhardt713aefa2010-03-23 04:07:21 +010042 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
Herbert Xu68b7c892010-02-27 19:41:40 +000043 netif_receive_skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044}
45
stephen hemmingereeaf61d2010-07-27 08:26:30 +000046/* note: already called with rcu_read_lock */
Linus Torvalds1da177e2005-04-16 15:20:36 -070047int br_handle_frame_finish(struct sk_buff *skb)
48{
49 const unsigned char *dest = eth_hdr(skb)->h_dest;
Jiri Pirkof350a0a2010-06-15 06:50:45 +000050 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080051 struct net_bridge *br;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 struct net_bridge_fdb_entry *dst;
Herbert Xuc4fcb782010-02-27 19:41:48 +000053 struct net_bridge_mdb_entry *mdst;
Herbert Xue081e1e2007-09-16 16:20:48 -070054 struct sk_buff *skb2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080056 if (!p || p->state == BR_STATE_DISABLED)
57 goto drop;
Stephen Hemminger85967bb2005-05-29 14:15:55 -070058
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080059 /* insert into forwarding database after filtering to avoid spoofing */
60 br = p->br;
61 br_fdb_update(br, p, eth_hdr(skb)->h_source);
62
Herbert Xuc4fcb782010-02-27 19:41:48 +000063 if (is_multicast_ether_addr(dest) &&
64 br_multicast_rcv(br, p, skb))
65 goto drop;
66
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080067 if (p->state == BR_STATE_LEARNING)
68 goto drop;
Stephen Hemminger0e5eaba2005-12-21 19:00:18 -080069
Herbert Xu68b7c892010-02-27 19:41:40 +000070 BR_INPUT_SKB_CB(skb)->brdev = br->dev;
71
Herbert Xue081e1e2007-09-16 16:20:48 -070072 /* The packet skb2 goes to the local host (NULL to skip). */
73 skb2 = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Herbert Xue081e1e2007-09-16 16:20:48 -070075 if (br->dev->flags & IFF_PROMISC)
76 skb2 = skb;
77
78 dst = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Kris Katterjohndbbc0982006-01-06 13:05:58 -080080 if (is_multicast_ether_addr(dest)) {
Herbert Xuc4fcb782010-02-27 19:41:48 +000081 mdst = br_mdb_get(br, skb);
YOSHIFUJI Hideaki / 吉藤英明32dec5d2010-03-15 21:51:18 +000082 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) {
Herbert Xuc4fcb782010-02-27 19:41:48 +000083 if ((mdst && !hlist_unhashed(&mdst->mglist)) ||
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
Pavel Emelyanova339f1c2008-05-21 14:13:47 -070093 br->dev->stats.multicast++;
Herbert Xue081e1e2007-09-16 16:20:48 -070094 } 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 }
99
Herbert Xue081e1e2007-09-16 16:20:48 -0700100 if (skb) {
101 if (dst)
Michael Braun7f7708f2010-03-16 00:26:22 -0700102 br_forward(dst->dst, skb, skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 else
Herbert Xub33084b2010-02-27 19:41:41 +0000104 br_flood_forward(br, skb, skb2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 }
106
Herbert Xu87557c12010-02-27 19:41:39 +0000107 if (skb2)
Herbert Xu68b7c892010-02-27 19:41:40 +0000108 return br_pass_frame_up(skb2);
Herbert Xu87557c12010-02-27 19:41:39 +0000109
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110out:
111 return 0;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800112drop:
113 kfree_skb(skb);
114 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115}
116
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000117/* note: already called with rcu_read_lock */
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800118static int br_handle_local_finish(struct sk_buff *skb)
119{
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000120 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800121
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000122 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800123 return 0; /* process further */
124}
125
126/* Does address match the link local multicast address.
127 * 01:80:c2:00:00:0X
128 */
Andrew Mortonb3e83d62006-03-20 23:00:56 -0800129static inline int is_link_local(const unsigned char *dest)
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800130{
Al Viro582ee432007-07-26 17:33:39 +0100131 __be16 *a = (__be16 *)dest;
132 static const __be16 *b = (const __be16 *)br_group_address;
YOSHIFUJI Hideaki91c5ec32007-12-12 03:51:03 +0900133 static const __be16 m = cpu_to_be16(0xfff0);
Stephen Hemmingerfd74e6c2007-03-12 16:25:32 -0700134
135 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800136}
137
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138/*
Stephen Hemminger6229e362007-03-21 13:38:47 -0700139 * Return NULL if skb is handled
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000140 * note: already called with rcu_read_lock
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 */
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000142struct sk_buff *br_handle_frame(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000144 struct net_bridge_port *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 const unsigned char *dest = eth_hdr(skb)->h_dest;
Eric Dumazeta386f992010-11-15 06:38:11 +0000146 br_should_route_hook_t *rhook;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Simon Hormanc2368e72010-08-22 17:35:32 +0000148 if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000149 return skb;
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
Stephen Hemminger467aea02007-03-21 13:42:06 -0700152 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Herbert Xu7b995652007-10-14 00:39:01 -0700154 skb = skb_share_check(skb, GFP_ATOMIC);
155 if (!skb)
156 return NULL;
157
Jiri Pirkof350a0a2010-06-15 06:50:45 +0000158 p = br_port_get_rcu(skb->dev);
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000159
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700160 if (unlikely(is_link_local(dest))) {
161 /* Pause frames shouldn't be passed up by driver anyway */
162 if (skb->protocol == htons(ETH_P_PAUSE))
163 goto drop;
164
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000165 /* If STP is turned off, then forward */
Benjamin Poirier1e253c32010-10-18 16:09:35 +0000166 if (p->br->stp_enabled == BR_NO_STP)
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000167 goto forward;
168
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100169 if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
Stephen Hemminger43aa1922008-06-17 16:09:45 -0700170 NULL, br_handle_local_finish))
171 return NULL; /* frame consumed by filter */
172 else
173 return skb; /* continue processing */
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700174 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000176forward:
Stephen Hemminger467aea02007-03-21 13:42:06 -0700177 switch (p->state) {
178 case BR_STATE_FORWARDING:
Pavel Emelyanov82de3822007-11-29 23:58:58 +1100179 rhook = rcu_dereference(br_should_route_hook);
Eric Dumazeta386f992010-11-15 06:38:11 +0000180 if (rhook) {
181 if ((*rhook)(skb))
Stephen Hemminger6229e362007-03-21 13:38:47 -0700182 return skb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 dest = eth_hdr(skb)->h_dest;
184 }
Stephen Hemminger467aea02007-03-21 13:42:06 -0700185 /* fall through */
186 case BR_STATE_LEARNING:
Stephen Hemminger6ede2462005-10-25 15:04:59 -0700187 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 skb->pkt_type = PACKET_HOST;
189
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100190 NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 br_handle_frame_finish);
Stephen Hemminger467aea02007-03-21 13:42:06 -0700192 break;
193 default:
194drop:
195 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 }
Stephen Hemminger6229e362007-03-21 13:38:47 -0700197 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198}