[BRIDGE]: use kcalloc
[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 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 = rcu_dereference(skb->dev->br_port);
49         struct net_bridge *br;
50         struct net_bridge_fdb_entry *dst;
51         int passedup = 0;
52
53         if (!p || p->state == BR_STATE_DISABLED)
54                 goto drop;
55
56         /* insert into forwarding database after filtering to avoid spoofing */
57         br = p->br;
58         br_fdb_update(br, p, eth_hdr(skb)->h_source);
59
60         if (p->state == BR_STATE_LEARNING)
61                 goto drop;
62
63         if (br->dev->flags & IFF_PROMISC) {
64                 struct sk_buff *skb2;
65
66                 skb2 = skb_clone(skb, GFP_ATOMIC);
67                 if (skb2 != NULL) {
68                         passedup = 1;
69                         br_pass_frame_up(br, skb2);
70                 }
71         }
72
73         if (is_multicast_ether_addr(dest)) {
74                 br_flood_forward(br, skb, !passedup);
75                 if (!passedup)
76                         br_pass_frame_up(br, skb);
77                 goto out;
78         }
79
80         dst = __br_fdb_get(br, dest);
81         if (dst != NULL && dst->is_local) {
82                 if (!passedup)
83                         br_pass_frame_up(br, skb);
84                 else
85                         kfree_skb(skb);
86                 goto out;
87         }
88
89         if (dst != NULL) {
90                 br_forward(dst->dst, skb);
91                 goto out;
92         }
93
94         br_flood_forward(br, skb, 0);
95
96 out:
97         return 0;
98 drop:
99         kfree_skb(skb);
100         goto out;
101 }
102
103 /*
104  * Called via br_handle_frame_hook.
105  * Return 0 if *pskb should be processed furthur
106  *        1 if *pskb is handled
107  * note: already called with rcu_read_lock (preempt_disabled) 
108  */
109 int br_handle_frame(struct net_bridge_port *p, struct sk_buff **pskb)
110 {
111         struct sk_buff *skb = *pskb;
112         const unsigned char *dest = eth_hdr(skb)->h_dest;
113
114         if (p->state == BR_STATE_DISABLED)
115                 goto err;
116
117         if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
118                 goto err;
119
120         if (p->br->stp_enabled &&
121             !memcmp(dest, bridge_ula, 5) &&
122             !(dest[5] & 0xF0)) {
123                 if (!dest[5]) {
124                         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev, 
125                                 NULL, br_stp_handle_bpdu);
126                         return 1;
127                 }
128                 goto err;
129         }
130
131         if (p->state == BR_STATE_FORWARDING || p->state == BR_STATE_LEARNING) {
132                 if (br_should_route_hook) {
133                         if (br_should_route_hook(pskb)) 
134                                 return 0;
135                         skb = *pskb;
136                         dest = eth_hdr(skb)->h_dest;
137                 }
138
139                 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
140                         skb->pkt_type = PACKET_HOST;
141
142                 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
143                         br_handle_frame_finish);
144                 return 1;
145         }
146
147 err:
148         kfree_skb(skb);
149         return 1;
150 }