2 * Handle incoming frames
3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * $Id: br_input.c,v 1.10 2001/12/24 04:50:20 davem Exp $
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.
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"
22 const unsigned char bridge_ula[6] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
24 static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
26 struct net_device *indev;
28 br->statistics.rx_packets++;
29 br->statistics.rx_bytes += skb->len;
34 NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
38 /* note: already called with rcu_read_lock (preempt_disabled) */
39 int br_handle_frame_finish(struct sk_buff *skb)
41 const unsigned char *dest = eth_hdr(skb)->h_dest;
42 struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
43 struct net_bridge *br;
44 struct net_bridge_fdb_entry *dst;
47 if (!p || p->state == BR_STATE_DISABLED)
50 /* insert into forwarding database after filtering to avoid spoofing */
52 br_fdb_update(br, p, eth_hdr(skb)->h_source);
54 if (p->state == BR_STATE_LEARNING)
57 if (br->dev->flags & IFF_PROMISC) {
60 skb2 = skb_clone(skb, GFP_ATOMIC);
63 br_pass_frame_up(br, skb2);
67 if (is_multicast_ether_addr(dest)) {
68 br_flood_forward(br, skb, !passedup);
70 br_pass_frame_up(br, skb);
74 dst = __br_fdb_get(br, dest);
75 if (dst != NULL && dst->is_local) {
77 br_pass_frame_up(br, skb);
84 br_forward(dst->dst, skb);
88 br_flood_forward(br, skb, 0);
97 /* note: already called with rcu_read_lock (preempt_disabled) */
98 static int br_handle_local_finish(struct sk_buff *skb)
100 struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
102 if (p && p->state != BR_STATE_DISABLED)
103 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
105 return 0; /* process further */
108 /* Does address match the link local multicast address.
111 static inline int is_link_local(const unsigned char *dest)
113 return memcmp(dest, bridge_ula, 5) == 0 && (dest[5] & 0xf0) == 0;
117 * Called via br_handle_frame_hook.
118 * Return 0 if *pskb should be processed furthur
119 * 1 if *pskb is handled
120 * note: already called with rcu_read_lock (preempt_disabled)
122 int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
124 struct sk_buff *skb = *pskb;
125 const unsigned char *dest = eth_hdr(skb)->h_dest;
127 if (p->state == BR_STATE_DISABLED)
130 if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
133 if (unlikely(is_link_local(dest))) {
134 skb->pkt_type = PACKET_HOST;
135 return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
136 NULL, br_handle_local_finish) != 0;
139 if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
140 if (br_should_route_hook) {
141 if (br_should_route_hook(pskb))
144 dest = eth_hdr(skb)->h_dest;
147 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
148 skb->pkt_type = PACKET_HOST;
150 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
151 br_handle_frame_finish);