Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Handle incoming frames |
| 3 | * Linux ethernet bridge |
| 4 | * |
| 5 | * Authors: |
| 6 | * Lennert Buytenhek <buytenh@gnu.org> |
| 7 | * |
| 8 | * $Id: br_input.c,v 1.10 2001/12/24 04:50:20 davem Exp $ |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
| 13 | * 2 of the License, or (at your option) any later version. |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/netdevice.h> |
| 18 | #include <linux/etherdevice.h> |
| 19 | #include <linux/netfilter_bridge.h> |
| 20 | #include "br_private.h" |
| 21 | |
Stephen Hemminger | fda93d9 | 2006-03-20 22:59:21 -0800 | [diff] [blame] | 22 | /* Bridge group multicast address 802.1d (pg 51). */ |
| 23 | const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb) |
| 26 | { |
| 27 | struct net_device *indev; |
| 28 | |
| 29 | br->statistics.rx_packets++; |
| 30 | br->statistics.rx_bytes += skb->len; |
| 31 | |
| 32 | indev = skb->dev; |
| 33 | skb->dev = br->dev; |
| 34 | |
| 35 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL, |
Stephen Hemminger | d5513a7 | 2006-03-20 22:57:18 -0800 | [diff] [blame] | 36 | netif_receive_skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | } |
| 38 | |
| 39 | /* note: already called with rcu_read_lock (preempt_disabled) */ |
| 40 | int br_handle_frame_finish(struct sk_buff *skb) |
| 41 | { |
| 42 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 43 | struct net_bridge_port *p = rcu_dereference(skb->dev->br_port); |
| 44 | struct net_bridge *br; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | struct net_bridge_fdb_entry *dst; |
| 46 | int passedup = 0; |
| 47 | |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 48 | if (!p || p->state == BR_STATE_DISABLED) |
| 49 | goto drop; |
Stephen Hemminger | 85967bb | 2005-05-29 14:15:55 -0700 | [diff] [blame] | 50 | |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 51 | /* insert into forwarding database after filtering to avoid spoofing */ |
| 52 | br = p->br; |
| 53 | br_fdb_update(br, p, eth_hdr(skb)->h_source); |
| 54 | |
| 55 | if (p->state == BR_STATE_LEARNING) |
| 56 | goto drop; |
Stephen Hemminger | 0e5eaba | 2005-12-21 19:00:18 -0800 | [diff] [blame] | 57 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | if (br->dev->flags & IFF_PROMISC) { |
| 59 | struct sk_buff *skb2; |
| 60 | |
| 61 | skb2 = skb_clone(skb, GFP_ATOMIC); |
| 62 | if (skb2 != NULL) { |
| 63 | passedup = 1; |
| 64 | br_pass_frame_up(br, skb2); |
| 65 | } |
| 66 | } |
| 67 | |
Kris Katterjohn | dbbc098 | 2006-01-06 13:05:58 -0800 | [diff] [blame] | 68 | if (is_multicast_ether_addr(dest)) { |
Stephen Hemminger | 1c29fc4 | 2006-05-05 17:07:13 -0700 | [diff] [blame] | 69 | br->statistics.multicast++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | br_flood_forward(br, skb, !passedup); |
| 71 | if (!passedup) |
| 72 | br_pass_frame_up(br, skb); |
| 73 | goto out; |
| 74 | } |
| 75 | |
| 76 | dst = __br_fdb_get(br, dest); |
| 77 | if (dst != NULL && dst->is_local) { |
| 78 | if (!passedup) |
| 79 | br_pass_frame_up(br, skb); |
| 80 | else |
| 81 | kfree_skb(skb); |
| 82 | goto out; |
| 83 | } |
| 84 | |
| 85 | if (dst != NULL) { |
| 86 | br_forward(dst->dst, skb); |
| 87 | goto out; |
| 88 | } |
| 89 | |
| 90 | br_flood_forward(br, skb, 0); |
| 91 | |
| 92 | out: |
| 93 | return 0; |
Stephen Hemminger | b3f1be4 | 2006-02-09 17:08:52 -0800 | [diff] [blame] | 94 | drop: |
| 95 | kfree_skb(skb); |
| 96 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | } |
| 98 | |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 99 | /* note: already called with rcu_read_lock (preempt_disabled) */ |
| 100 | static int br_handle_local_finish(struct sk_buff *skb) |
| 101 | { |
| 102 | struct net_bridge_port *p = rcu_dereference(skb->dev->br_port); |
| 103 | |
| 104 | if (p && p->state != BR_STATE_DISABLED) |
| 105 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source); |
| 106 | |
| 107 | return 0; /* process further */ |
| 108 | } |
| 109 | |
| 110 | /* Does address match the link local multicast address. |
| 111 | * 01:80:c2:00:00:0X |
| 112 | */ |
Andrew Morton | b3e83d6 | 2006-03-20 23:00:56 -0800 | [diff] [blame] | 113 | static inline int is_link_local(const unsigned char *dest) |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 114 | { |
Al Viro | 582ee43 | 2007-07-26 17:33:39 +0100 | [diff] [blame] | 115 | __be16 *a = (__be16 *)dest; |
| 116 | static const __be16 *b = (const __be16 *)br_group_address; |
| 117 | static const __be16 m = __constant_cpu_to_be16(0xfff0); |
Stephen Hemminger | fd74e6c | 2007-03-12 16:25:32 -0700 | [diff] [blame] | 118 | |
| 119 | return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0; |
Stephen Hemminger | cf0f02d | 2006-03-20 22:59:06 -0800 | [diff] [blame] | 120 | } |
| 121 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | /* |
| 123 | * Called via br_handle_frame_hook. |
Stephen Hemminger | 6229e36 | 2007-03-21 13:38:47 -0700 | [diff] [blame] | 124 | * Return NULL if skb is handled |
YOSHIFUJI Hideaki | 9d6f229 | 2007-02-09 23:24:35 +0900 | [diff] [blame] | 125 | * note: already called with rcu_read_lock (preempt_disabled) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | */ |
Stephen Hemminger | 6229e36 | 2007-03-21 13:38:47 -0700 | [diff] [blame] | 127 | struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
| 130 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
Stephen Hemminger | 467aea0 | 2007-03-21 13:42:06 -0700 | [diff] [blame] | 132 | goto drop; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Stephen Hemminger | 2111f8b | 2007-04-25 22:05:55 -0700 | [diff] [blame] | 134 | if (unlikely(is_link_local(dest))) { |
| 135 | /* Pause frames shouldn't be passed up by driver anyway */ |
| 136 | if (skb->protocol == htons(ETH_P_PAUSE)) |
| 137 | goto drop; |
| 138 | |
Stephen Hemminger | c2886d6 | 2007-04-25 22:07:58 -0700 | [diff] [blame] | 139 | /* Process STP BPDU's through normal netif_receive_skb() path */ |
| 140 | if (p->br->stp_enabled != BR_NO_STP) { |
| 141 | if (NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, |
| 142 | NULL, br_handle_local_finish)) |
| 143 | return NULL; |
| 144 | else |
| 145 | return skb; |
| 146 | } |
Stephen Hemminger | 2111f8b | 2007-04-25 22:05:55 -0700 | [diff] [blame] | 147 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | |
Stephen Hemminger | 467aea0 | 2007-03-21 13:42:06 -0700 | [diff] [blame] | 149 | switch (p->state) { |
| 150 | case BR_STATE_FORWARDING: |
| 151 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | if (br_should_route_hook) { |
Stephen Hemminger | 6229e36 | 2007-03-21 13:38:47 -0700 | [diff] [blame] | 153 | if (br_should_route_hook(&skb)) |
| 154 | return skb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | dest = eth_hdr(skb)->h_dest; |
| 156 | } |
Stephen Hemminger | 467aea0 | 2007-03-21 13:42:06 -0700 | [diff] [blame] | 157 | /* fall through */ |
| 158 | case BR_STATE_LEARNING: |
Stephen Hemminger | 6ede246 | 2005-10-25 15:04:59 -0700 | [diff] [blame] | 159 | if (!compare_ether_addr(p->br->dev->dev_addr, dest)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | skb->pkt_type = PACKET_HOST; |
| 161 | |
| 162 | NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
| 163 | br_handle_frame_finish); |
Stephen Hemminger | 467aea0 | 2007-03-21 13:42:06 -0700 | [diff] [blame] | 164 | break; |
| 165 | default: |
| 166 | drop: |
| 167 | kfree_skb(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | } |
Stephen Hemminger | 6229e36 | 2007-03-21 13:38:47 -0700 | [diff] [blame] | 169 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | } |