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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>
Paul Gortmakerbc3b2d72011-07-15 11:47:34 -040019#include <linux/export.h>
Vlad Yasevicha37b85c2013-02-13 12:00:10 +000020#include <linux/rculist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include "br_private.h"
22
Eric Dumazeta386f992010-11-15 06:38:11 +000023/* Hook for brouter */
24br_should_route_hook_t __rcu *br_should_route_hook __read_mostly;
25EXPORT_SYMBOL(br_should_route_hook);
26
Herbert Xu68b7c892010-02-27 19:41:40 +000027static int br_pass_frame_up(struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -070028{
Herbert Xu68b7c892010-02-27 19:41:40 +000029 struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
stephen hemminger14bb4782010-03-02 13:32:09 +000030 struct net_bridge *br = netdev_priv(brdev);
Li RongQing8f849852014-01-04 13:57:59 +080031 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Eric Dumazet406818f2010-06-23 13:00:48 -070033 u64_stats_update_begin(&brstats->syncp);
stephen hemminger14bb4782010-03-02 13:32:09 +000034 brstats->rx_packets++;
35 brstats->rx_bytes += skb->len;
Eric Dumazet406818f2010-06-23 13:00:48 -070036 u64_stats_update_end(&brstats->syncp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Vlad Yasevich85f46c62013-02-13 12:00:11 +000038 /* Bridge is just like any other port. Make sure the
39 * packet is allowed except in promisc modue when someone
40 * may be running packet capture.
41 */
42 if (!(brdev->flags & IFF_PROMISC) &&
43 !br_allowed_egress(br, br_get_vlan_info(br), skb)) {
44 kfree_skb(skb);
45 return NET_RX_DROP;
46 }
47
Vlad Yasevich78851982013-02-13 12:00:14 +000048 skb = br_handle_vlan(br, br_get_vlan_info(br), skb);
49 if (!skb)
50 return NET_RX_DROP;
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 indev = skb->dev;
Pavel Emelyanova339f1c2008-05-21 14:13:47 -070053 skb->dev = brdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
Jan Engelhardt713aefa2010-03-23 04:07:21 +010055 return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
Herbert Xu68b7c892010-02-27 19:41:40 +000056 netif_receive_skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
stephen hemmingereeaf61d2010-07-27 08:26:30 +000059/* note: already called with rcu_read_lock */
Linus Torvalds1da177e2005-04-16 15:20:36 -070060int br_handle_frame_finish(struct sk_buff *skb)
61{
62 const unsigned char *dest = eth_hdr(skb)->h_dest;
Jiri Pirkof350a0a82010-06-15 06:50:45 +000063 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080064 struct net_bridge *br;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 struct net_bridge_fdb_entry *dst;
Herbert Xuc4fcb782010-02-27 19:41:48 +000066 struct net_bridge_mdb_entry *mdst;
Herbert Xue081e1e2007-09-16 16:20:48 -070067 struct sk_buff *skb2;
Vlad Yasevich867a5942013-06-05 10:08:01 -040068 bool unicast = true;
Vlad Yasevich78851982013-02-13 12:00:14 +000069 u16 vid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080071 if (!p || p->state == BR_STATE_DISABLED)
72 goto drop;
Stephen Hemminger85967bb2005-05-29 14:15:55 -070073
Vlad Yasevich78851982013-02-13 12:00:14 +000074 if (!br_allowed_ingress(p->br, nbp_get_vlan_info(p), skb, &vid))
Vlad Yasevicha37b85c2013-02-13 12:00:10 +000075 goto drop;
76
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080077 /* insert into forwarding database after filtering to avoid spoofing */
78 br = p->br;
Vlad Yasevich9ba18892013-06-05 10:08:00 -040079 if (p->flags & BR_LEARNING)
80 br_fdb_update(br, p, eth_hdr(skb)->h_source, vid);
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080081
Herbert Xu44661462011-07-05 13:58:33 +000082 if (!is_broadcast_ether_addr(dest) && is_multicast_ether_addr(dest) &&
Vlad Yasevich06499092013-10-28 15:45:07 -040083 br_multicast_rcv(br, p, skb, vid))
Herbert Xuc4fcb782010-02-27 19:41:48 +000084 goto drop;
85
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -080086 if (p->state == BR_STATE_LEARNING)
87 goto drop;
Stephen Hemminger0e5eaba2005-12-21 19:00:18 -080088
Herbert Xu68b7c892010-02-27 19:41:40 +000089 BR_INPUT_SKB_CB(skb)->brdev = br->dev;
90
Herbert Xue081e1e2007-09-16 16:20:48 -070091 /* The packet skb2 goes to the local host (NULL to skip). */
92 skb2 = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
Herbert Xue081e1e2007-09-16 16:20:48 -070094 if (br->dev->flags & IFF_PROMISC)
95 skb2 = skb;
96
97 dst = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Vlad Yasevich867a5942013-06-05 10:08:01 -040099 if (is_broadcast_ether_addr(dest)) {
Herbert Xu44661462011-07-05 13:58:33 +0000100 skb2 = skb;
Vlad Yasevich867a5942013-06-05 10:08:01 -0400101 unicast = false;
102 } else if (is_multicast_ether_addr(dest)) {
Cong Wangfbca58a2013-03-07 03:05:33 +0000103 mdst = br_mdb_get(br, skb, vid);
Linus Lüssingb00589a2013-08-01 01:06:20 +0200104 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
Linus Lüssingcc0fdd82013-08-30 17:28:17 +0200105 br_multicast_querier_exists(br, eth_hdr(skb))) {
Herbert Xu8a870172011-02-12 01:05:42 -0800106 if ((mdst && mdst->mglist) ||
Herbert Xuc4fcb782010-02-27 19:41:48 +0000107 br_multicast_is_router(br))
108 skb2 = skb;
109 br_multicast_forward(mdst, skb, skb2);
110 skb = NULL;
111 if (!skb2)
112 goto out;
113 } else
114 skb2 = skb;
115
Vlad Yasevich867a5942013-06-05 10:08:01 -0400116 unicast = false;
Pavel Emelyanova339f1c2008-05-21 14:13:47 -0700117 br->dev->stats.multicast++;
Vlad Yasevich2ba071e2013-02-13 12:00:16 +0000118 } else if ((dst = __br_fdb_get(br, dest, vid)) &&
119 dst->is_local) {
Herbert Xue081e1e2007-09-16 16:20:48 -0700120 skb2 = skb;
121 /* Do not forward the packet since it's local. */
122 skb = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 }
124
Herbert Xue081e1e2007-09-16 16:20:48 -0700125 if (skb) {
stephen hemminger7cd88612011-04-04 14:03:28 +0000126 if (dst) {
127 dst->used = jiffies;
Michael Braun7f7708f2010-03-16 00:26:22 -0700128 br_forward(dst->dst, skb, skb2);
stephen hemminger7cd88612011-04-04 14:03:28 +0000129 } else
Vlad Yasevich867a5942013-06-05 10:08:01 -0400130 br_flood_forward(br, skb, skb2, unicast);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 }
132
Herbert Xu87557c12010-02-27 19:41:39 +0000133 if (skb2)
Herbert Xu68b7c892010-02-27 19:41:40 +0000134 return br_pass_frame_up(skb2);
Herbert Xu87557c12010-02-27 19:41:39 +0000135
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136out:
137 return 0;
Stephen Hemmingerb3f1be42006-02-09 17:08:52 -0800138drop:
139 kfree_skb(skb);
140 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141}
142
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000143/* note: already called with rcu_read_lock */
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800144static int br_handle_local_finish(struct sk_buff *skb)
145{
Jiri Pirkof350a0a82010-06-15 06:50:45 +0000146 struct net_bridge_port *p = br_port_get_rcu(skb->dev);
Vlad Yasevich2ba071e2013-02-13 12:00:16 +0000147 u16 vid = 0;
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800148
Vlad Yasevich2ba071e2013-02-13 12:00:16 +0000149 br_vlan_get_tag(skb, &vid);
Vlad Yasevich9ba18892013-06-05 10:08:00 -0400150 if (p->flags & BR_LEARNING)
151 br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid);
Stephen Hemmingercf0f02d2006-03-20 22:59:06 -0800152 return 0; /* process further */
153}
154
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155/*
Stephen Hemminger6229e362007-03-21 13:38:47 -0700156 * Return NULL if skb is handled
stephen hemmingereeaf61d2010-07-27 08:26:30 +0000157 * note: already called with rcu_read_lock
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 */
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000159rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160{
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000161 struct net_bridge_port *p;
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000162 struct sk_buff *skb = *pskb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 const unsigned char *dest = eth_hdr(skb)->h_dest;
Eric Dumazeta386f992010-11-15 06:38:11 +0000164 br_should_route_hook_t *rhook;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Simon Hormanc2368e72010-08-22 17:35:32 +0000166 if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000167 return RX_HANDLER_PASS;
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000168
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
Stephen Hemminger467aea02007-03-21 13:42:06 -0700170 goto drop;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
Herbert Xu7b995652007-10-14 00:39:01 -0700172 skb = skb_share_check(skb, GFP_ATOMIC);
173 if (!skb)
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000174 return RX_HANDLER_CONSUMED;
Herbert Xu7b995652007-10-14 00:39:01 -0700175
Jiri Pirkof350a0a82010-06-15 06:50:45 +0000176 p = br_port_get_rcu(skb->dev);
Jiri Pirkoab95bfe2010-06-01 21:52:08 +0000177
Ben Hutchings46acc462012-11-01 09:11:11 +0000178 if (unlikely(is_link_local_ether_addr(dest))) {
stephen hemminger515853c2011-10-03 18:14:46 +0000179 /*
180 * See IEEE 802.1D Table 7-10 Reserved addresses
181 *
182 * Assignment Value
183 * Bridge Group Address 01-80-C2-00-00-00
184 * (MAC Control) 802.3 01-80-C2-00-00-01
185 * (Link Aggregation) 802.3 01-80-C2-00-00-02
186 * 802.1X PAE address 01-80-C2-00-00-03
187 *
188 * 802.1AB LLDP 01-80-C2-00-00-0E
189 *
190 * Others reserved for future standardization
191 */
192 switch (dest[5]) {
193 case 0x00: /* Bridge Group Address */
194 /* If STP is turned off,
195 then must forward to keep loop detection */
196 if (p->br->stp_enabled == BR_NO_STP)
197 goto forward;
198 break;
199
200 case 0x01: /* IEEE MAC (Pause) */
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700201 goto drop;
202
stephen hemminger515853c2011-10-03 18:14:46 +0000203 default:
204 /* Allow selective forwarding for most other protocols */
205 if (p->br->group_fwd_mask & (1u << dest[5]))
206 goto forward;
207 }
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000208
stephen hemminger515853c2011-10-03 18:14:46 +0000209 /* Deliver packet to local host only */
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100210 if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000211 NULL, br_handle_local_finish)) {
212 return RX_HANDLER_CONSUMED; /* consumed by filter */
213 } else {
214 *pskb = skb;
215 return RX_HANDLER_PASS; /* continue processing */
216 }
Stephen Hemminger2111f8b2007-04-25 22:05:55 -0700217 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
Stephen Hemmingera598f6a2009-05-15 06:10:13 +0000219forward:
Stephen Hemminger467aea02007-03-21 13:42:06 -0700220 switch (p->state) {
221 case BR_STATE_FORWARDING:
Pavel Emelyanov82de3822007-11-29 23:58:58 +1100222 rhook = rcu_dereference(br_should_route_hook);
Eric Dumazeta386f992010-11-15 06:38:11 +0000223 if (rhook) {
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000224 if ((*rhook)(skb)) {
225 *pskb = skb;
226 return RX_HANDLER_PASS;
227 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 dest = eth_hdr(skb)->h_dest;
229 }
Stephen Hemminger467aea02007-03-21 13:42:06 -0700230 /* fall through */
231 case BR_STATE_LEARNING:
Joe Perches9a7b6ef92012-05-08 18:56:49 +0000232 if (ether_addr_equal(p->br->dev->dev_addr, dest))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 skb->pkt_type = PACKET_HOST;
234
Jan Engelhardt713aefa2010-03-23 04:07:21 +0100235 NF_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 br_handle_frame_finish);
Stephen Hemminger467aea02007-03-21 13:42:06 -0700237 break;
238 default:
239drop:
240 kfree_skb(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 }
Jiri Pirko8a4eb572011-03-12 03:14:39 +0000242 return RX_HANDLER_CONSUMED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243}