[DCCP]: Fix leak in net/dccp/ipv4.c
[linux-2.6.git] / 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 1.10 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 /* Bridge group multicast address 802.1d (pg 51). */
23 const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
24
25 static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
26 {
27         struct net_device *indev;
28
29         br->statistics.rx_packets++;
30         br->statistics.rx_bytes += skb->len;
31
32         indev = skb->dev;
33         skb->dev = br->dev;
34
35         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
36                 netif_receive_skb);
37 }
38
39 /* note: already called with rcu_read_lock (preempt_disabled) */
40 int br_handle_frame_finish(struct sk_buff *skb)
41 {
42         const unsigned char *dest = eth_hdr(skb)->h_dest;
43         struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
44         struct net_bridge *br;
45         struct net_bridge_fdb_entry *dst;
46         int passedup = 0;
47
48         if (!p || p->state == BR_STATE_DISABLED)
49                 goto drop;
50
51         /* insert into forwarding database after filtering to avoid spoofing */
52         br = p->br;
53         br_fdb_update(br, p, eth_hdr(skb)->h_source);
54
55         if (p->state == BR_STATE_LEARNING)
56                 goto drop;
57
58         if (br->dev->flags & IFF_PROMISC) {
59                 struct sk_buff *skb2;
60
61                 skb2 = skb_clone(skb, GFP_ATOMIC);
62                 if (skb2 != NULL) {
63                         passedup = 1;
64                         br_pass_frame_up(br, skb2);
65                 }
66         }
67
68         if (is_multicast_ether_addr(dest)) {
69                 br_flood_forward(br, skb, !passedup);
70                 if (!passedup)
71                         br_pass_frame_up(br, skb);
72                 goto out;
73         }
74
75         dst = __br_fdb_get(br, dest);
76         if (dst != NULL && dst->is_local) {
77                 if (!passedup)
78                         br_pass_frame_up(br, skb);
79                 else
80                         kfree_skb(skb);
81                 goto out;
82         }
83
84         if (dst != NULL) {
85                 br_forward(dst->dst, skb);
86                 goto out;
87         }
88
89         br_flood_forward(br, skb, 0);
90
91 out:
92         return 0;
93 drop:
94         kfree_skb(skb);
95         goto out;
96 }
97
98 /* note: already called with rcu_read_lock (preempt_disabled) */
99 static int br_handle_local_finish(struct sk_buff *skb)
100 {
101         struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
102
103         if (p && p->state != BR_STATE_DISABLED)
104                 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
105
106         return 0;        /* process further */
107 }
108
109 /* Does address match the link local multicast address.
110  * 01:80:c2:00:00:0X
111  */
112 static inline int is_link_local(const unsigned char *dest)
113 {
114         return memcmp(dest, br_group_address, 5) == 0 && (dest[5] & 0xf0) == 0;
115 }
116
117 /*
118  * Called via br_handle_frame_hook.
119  * Return 0 if *pskb should be processed furthur
120  *        1 if *pskb is handled
121  * note: already called with rcu_read_lock (preempt_disabled) 
122  */
123 int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
124 {
125         struct sk_buff *skb = *pskb;
126         const unsigned char *dest = eth_hdr(skb)->h_dest;
127
128         if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
129                 goto err;
130
131         if (unlikely(is_link_local(dest))) {
132                 skb->pkt_type = PACKET_HOST;
133                 return NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
134                                NULL, br_handle_local_finish) != 0;
135         }
136
137         if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
138                 if (br_should_route_hook) {
139                         if (br_should_route_hook(pskb)) 
140                                 return 0;
141                         skb = *pskb;
142                         dest = eth_hdr(skb)->h_dest;
143                 }
144
145                 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
146                         skb->pkt_type = PACKET_HOST;
147
148                 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
149                         br_handle_frame_finish);
150                 return 1;
151         }
152
153 err:
154         kfree_skb(skb);
155         return 1;
156 }