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 { 26 #ifdef CONFIG_NETFILTER_DEBUG 27 skb->nf_debug = 0; 28 #endif 29 netif_receive_skb(skb); 30 31 return 0; 32 } 33 34 static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb) 35 { 36 struct net_device *indev; 37 38 br->statistics.rx_packets++; 39 br->statistics.rx_bytes += skb->len; 40 41 indev = skb->dev; 42 skb->dev = br->dev; 43 44 NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL, 45 br_pass_frame_up_finish); 46 } 47 48 /* note: already called with rcu_read_lock (preempt_disabled) */ 49 int br_handle_frame_finish(struct sk_buff *skb) 50 { 51 const unsigned char *dest = eth_hdr(skb)->h_dest; 52 struct net_bridge_port *p = skb->dev->br_port; 53 struct net_bridge *br = p->br; 54 struct net_bridge_fdb_entry *dst; 55 int passedup = 0; 56 57 /* insert into forwarding database after filtering to avoid spoofing */ 58 br_fdb_update(p->br, p, eth_hdr(skb)->h_source); 59 60 if (br->dev->flags & IFF_PROMISC) { 61 struct sk_buff *skb2; 62 63 skb2 = skb_clone(skb, GFP_ATOMIC); 64 if (skb2 != NULL) { 65 passedup = 1; 66 br_pass_frame_up(br, skb2); 67 } 68 } 69 70 if (dest[0] & 1) { 71 br_flood_forward(br, skb, !passedup); 72 if (!passedup) 73 br_pass_frame_up(br, skb); 74 goto out; 75 } 76 77 dst = __br_fdb_get(br, dest); 78 if (dst != NULL && dst->is_local) { 79 if (!passedup) 80 br_pass_frame_up(br, skb); 81 else 82 kfree_skb(skb); 83 goto out; 84 } 85 86 if (dst != NULL) { 87 br_forward(dst->dst, skb); 88 goto out; 89 } 90 91 br_flood_forward(br, skb, 0); 92 93 out: 94 return 0; 95 } 96 97 /* 98 * Called via br_handle_frame_hook. 99 * Return 0 if *pskb should be processed furthur 100 * 1 if *pskb is handled 101 * note: already called with rcu_read_lock (preempt_disabled) 102 */ 103 int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb) 104 { 105 struct sk_buff *skb = *pskb; 106 const unsigned char *dest = eth_hdr(skb)->h_dest; 107 108 if (p->state == BR_STATE_DISABLED) 109 goto err; 110 111 if (!is_valid_ether_addr(eth_hdr(skb)->h_source)) 112 goto err; 113 114 if (p->state == BR_STATE_LEARNING) 115 br_fdb_update(p->br, p, eth_hdr(skb)->h_source); 116 117 if (p->br->stp_enabled && 118 !memcmp(dest, bridge_ula, 5) && 119 !(dest[5] & 0xF0)) { 120 if (!dest[5]) { 121 NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, 122 NULL, br_stp_handle_bpdu); 123 return 1; 124 } 125 } 126 127 else if (p->state == BR_STATE_FORWARDING) { 128 if (br_should_route_hook) { 129 if (br_should_route_hook(pskb)) 130 return 0; 131 skb = *pskb; 132 dest = eth_hdr(skb)->h_dest; 133 } 134 135 if (!memcmp(p->br->dev->dev_addr, dest, ETH_ALEN)) 136 skb->pkt_type = PACKET_HOST; 137 138 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL, 139 br_handle_frame_finish); 140 return 1; 141 } 142 143 err: 144 kfree_skb(skb); 145 return 1; 146 } 147