net/bridge/br_input.c

   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 1.1.1.1 2005/04/11 02:51:12 jack 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/if_bridge.h>
  20 #include <linux/netfilter_bridge.h>
  21 #include "br_private.h"
  22
  23 unsigned char bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
  24 extern long Packets; //jack20040813+
  25
  26 static int br_pass_frame_up_finish(struct sk_buff *skb)
  27 {
  28 #ifdef CONFIG_NETFILTER_DEBUG
  29         skb->nf_debug = 0;
  30 #endif
  31         netif_rx(skb);
  32
  33         return 0;
  34 }
  35
  36 static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
  37 {
  38         struct net_device *indev;
  39
  40         br->statistics.rx_packets++;
  41         Packets++;      //jack20040813+
  42         br->statistics.rx_bytes += skb->len;
  43
  44         indev = skb->dev;
  45         skb->dev = &br->dev;
  46         skb->pkt_type = PACKET_HOST;
  47         skb_push(skb, ETH_HLEN);
  48         skb->protocol = eth_type_trans(skb, &br->dev);
  49
  50         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
  51                         br_pass_frame_up_finish);
  52 }
  53
  54 static int br_handle_frame_finish(struct sk_buff *skb)
  55 {
  56         struct net_bridge *br;
  57         unsigned char *dest;
  58         struct net_bridge_fdb_entry *dst;
  59         struct net_bridge_port *p;
  60         int passedup;
  61
  62         dest = skb->mac.ethernet->h_dest;
  63
  64         p = skb->dev->br_port;
  65         if (p == NULL)
  66                 goto err_nolock;
  67
  68         br = p->br;
  69         read_lock(&br->lock);
  70         if (skb->dev->br_port == NULL)
  71                 goto err;
  72
  73         passedup = 0;
  74         if (br->dev.flags & IFF_PROMISC) {
  75                 struct sk_buff *skb2;
  76
  77                 skb2 = skb_clone(skb, GFP_ATOMIC);
  78                 if (skb2 != NULL) {
  79                         passedup = 1;
  80                         br_pass_frame_up(br, skb2);
  81                 }
  82         }
  83
  84         if (dest[0] & 1) {
  85                 br_flood_forward(br, skb, !passedup);
  86                 if (!passedup)
  87                         br_pass_frame_up(br, skb);
  88                 goto out;
  89         }
  90
  91         dst = br_fdb_get(br, dest);
  92         if (dst != NULL && dst->is_local) {
  93                 if (!passedup)
  94                         br_pass_frame_up(br, skb);
  95                 else
  96                         kfree_skb(skb);
  97                 br_fdb_put(dst);
  98                 goto out;
  99         }
 100
 101         if (dst != NULL) {
 102                 br_forward(dst->dst, skb);
 103                 br_fdb_put(dst);
 104                 goto out;
 105         }
 106
 107         br_flood_forward(br, skb, 0);
 108
 109 out:
 110         read_unlock(&br->lock);
 111         return 0;
 112
 113 err:
 114         read_unlock(&br->lock);
 115 err_nolock:
 116         kfree_skb(skb);
 117         return 0;
 118 }
 119
 120 int br_handle_frame(struct sk_buff *skb)
 121 {
 122         struct net_bridge *br;
 123         unsigned char *dest;
 124         struct net_bridge_port *p;
 125
 126         dest = skb->mac.ethernet->h_dest;
 127
 128         p = skb->dev->br_port;
 129         if (p == NULL)
 130                 goto err_nolock;
 131
 132         br = p->br;
 133         read_lock(&br->lock);
 134         if (skb->dev->br_port == NULL)
 135                 goto err;
 136
 137         if (!(br->dev.flags & IFF_UP) ||
 138             p->state == BR_STATE_DISABLED)
 139                 goto err;
 140
 141         if (skb->mac.ethernet->h_source[0] & 1)
 142                 goto err;
 143
 144         if (p->state == BR_STATE_LEARNING ||
 145             p->state == BR_STATE_FORWARDING)
 146                 br_fdb_insert(br, p, skb->mac.ethernet->h_source, 0);
 147
 148         if (br->stp_enabled &&
 149             !memcmp(dest, bridge_ula, 5) &&
 150             !(dest[5] & 0xF0))
 151                 goto handle_special_frame;
 152
 153         if (p->state == BR_STATE_FORWARDING) {
 154                 if (br_should_route_hook && br_should_route_hook(&skb)) {
 155                         read_unlock(&br->lock);
 156                         return -1;
 157                 }
 158
 159                 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
 160                         br_handle_frame_finish);
 161                 read_unlock(&br->lock);
 162                 return 0;
 163         }
 164
 165 err:
 166         read_unlock(&br->lock);
 167 err_nolock:
 168         kfree_skb(skb);
 169         return 0;
 170
 171 handle_special_frame:
 172         if (!dest[5]) {
 173                 br_stp_handle_bpdu(skb);
 174                 read_unlock(&br->lock);
 175                 return 0;
 176         }
 177
 178         read_unlock(&br->lock);
 179         kfree_skb(skb);
 180         return 0;
 181 }