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 netif_receive_skb(skb); 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 53 /* insert into forwarding database after filtering to avoid spoofing */ 54 br_fdb_update(p->br, p, eth_hdr(skb)->h_source); 55 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; 109 110 if (p->state == BR_STATE_LEARNING) 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 } 130 131 if (!compare_ether_addr(p->br->dev->dev_addr, dest)) 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 } 143