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 | |
| 22 | const unsigned char bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }; |
| 23 | |
| 24 | static int br_pass_frame_up_finish(struct sk_buff *skb) |
| 25 | { |
Stephen Hemminger | 7ce54e3 | 2005-05-29 14:16:48 -0700 | [diff] [blame] | 26 | netif_receive_skb(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 27 | return 0; |
| 28 | } |
| 29 | |
| 30 | static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb) |
| 31 | { |
| 32 | struct net_device *indev; |
| 33 | |
| 34 | br->statistics.rx_packets++; |
| 35 | br->statistics.rx_bytes += skb->len; |
| 36 | |
| 37 | indev = skb->dev; |
| 38 | skb->dev = br->dev; |
| 39 | |
| 40 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL, |
| 41 | br_pass_frame_up_finish); |
| 42 | } |
| 43 | |
| 44 | /* note: already called with rcu_read_lock (preempt_disabled) */ |
| 45 | int br_handle_frame_finish(struct sk_buff *skb) |
| 46 | { |
| 47 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
| 48 | struct net_bridge_port *p = skb->dev->br_port; |
| 49 | struct net_bridge *br = p->br; |
| 50 | struct net_bridge_fdb_entry *dst; |
| 51 | int passedup = 0; |
| 52 | |
Stephen Hemminger | 85967bb | 2005-05-29 14:15:55 -0700 | [diff] [blame] | 53 | /* insert into forwarding database after filtering to avoid spoofing */ |
| 54 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source); |
| 55 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | if (br->dev->flags & IFF_PROMISC) { |
| 57 | struct sk_buff *skb2; |
| 58 | |
| 59 | skb2 = skb_clone(skb, GFP_ATOMIC); |
| 60 | if (skb2 != NULL) { |
| 61 | passedup = 1; |
| 62 | br_pass_frame_up(br, skb2); |
| 63 | } |
| 64 | } |
| 65 | |
| 66 | if (dest[0] & 1) { |
| 67 | br_flood_forward(br, skb, !passedup); |
| 68 | if (!passedup) |
| 69 | br_pass_frame_up(br, skb); |
| 70 | goto out; |
| 71 | } |
| 72 | |
| 73 | dst = __br_fdb_get(br, dest); |
| 74 | if (dst != NULL && dst->is_local) { |
| 75 | if (!passedup) |
| 76 | br_pass_frame_up(br, skb); |
| 77 | else |
| 78 | kfree_skb(skb); |
| 79 | goto out; |
| 80 | } |
| 81 | |
| 82 | if (dst != NULL) { |
| 83 | br_forward(dst->dst, skb); |
| 84 | goto out; |
| 85 | } |
| 86 | |
| 87 | br_flood_forward(br, skb, 0); |
| 88 | |
| 89 | out: |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * Called via br_handle_frame_hook. |
| 95 | * Return 0 if *pskb should be processed furthur |
| 96 | * 1 if *pskb is handled |
| 97 | * note: already called with rcu_read_lock (preempt_disabled) |
| 98 | */ |
| 99 | int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb) |
| 100 | { |
| 101 | struct sk_buff *skb = *pskb; |
| 102 | const unsigned char *dest = eth_hdr(skb)->h_dest; |
| 103 | |
| 104 | if (p->state == BR_STATE_DISABLED) |
| 105 | goto err; |
| 106 | |
| 107 | if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) |
| 108 | goto err; |
| 109 | |
Stephen Hemminger | 85967bb | 2005-05-29 14:15:55 -0700 | [diff] [blame] | 110 | if (p->state == BR_STATE_LEARNING) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | br_fdb_update(p->br, p, eth_hdr(skb)->h_source); |
| 112 | |
| 113 | if (p->br->stp_enabled && |
| 114 | !memcmp(dest, bridge_ula, 5) && |
| 115 | !(dest[5] & 0xF0)) { |
| 116 | if (!dest[5]) { |
| 117 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, |
| 118 | NULL, br_stp_handle_bpdu); |
| 119 | return 1; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | else if (p->state == BR_STATE_FORWARDING) { |
| 124 | if (br_should_route_hook) { |
| 125 | if (br_should_route_hook(pskb)) |
| 126 | return 0; |
| 127 | skb = *pskb; |
| 128 | dest = eth_hdr(skb)->h_dest; |
| 129 | } |
| 130 | |
Stephen Hemminger | 6ede246 | 2005-10-25 15:04:59 -0700 | [diff] [blame] | 131 | if (!compare_ether_addr(p->br->dev->dev_addr, dest)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | skb->pkt_type = PACKET_HOST; |
| 133 | |
| 134 | NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, |
| 135 | br_handle_frame_finish); |
| 136 | return 1; |
| 137 | } |
| 138 | |
| 139 | err: |
| 140 | kfree_skb(skb); |
| 141 | return 1; |
| 142 | } |