[DCCP]: Fix leak in net/dccp/ipv4.c
[linux-2.6.git] / net / bridge / br_forward.c
1 /*
2  *      Forwarding decision
3  *      Linux ethernet bridge
4  *
5  *      Authors:
6  *      Lennert Buytenhek               <buytenh@gnu.org>
7  *
8  *      $Id: br_forward.c,v 1.4 2001/08/14 22:05:57 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/skbuff.h>
19 #include <linux/netfilter_bridge.h>
20 #include "br_private.h"
21
22 static inline int should_deliver(const struct net_bridge_port *p, 
23                                  const struct sk_buff *skb)
24 {
25         if (skb->dev == p->dev ||
26             p->state != BR_STATE_FORWARDING)
27                 return 0;
28
29         return 1;
30 }
31
32 int br_dev_queue_push_xmit(struct sk_buff *skb)
33 {
34         /* drop mtu oversized packets except tso */
35         if (skb->len > skb->dev->mtu && !skb_shinfo(skb)->tso_size)
36                 kfree_skb(skb);
37         else {
38 #ifdef CONFIG_BRIDGE_NETFILTER
39                 /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */
40                 nf_bridge_maybe_copy_header(skb);
41 #endif
42                 skb_push(skb, ETH_HLEN);
43
44                 dev_queue_xmit(skb);
45         }
46
47         return 0;
48 }
49
50 int br_forward_finish(struct sk_buff *skb)
51 {
52         NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
53                         br_dev_queue_push_xmit);
54
55         return 0;
56 }
57
58 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
59 {
60         skb->dev = to->dev;
61         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
62                         br_forward_finish);
63 }
64
65 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
66 {
67         struct net_device *indev;
68
69         indev = skb->dev;
70         skb->dev = to->dev;
71         skb->ip_summed = CHECKSUM_NONE;
72
73         NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
74                         br_forward_finish);
75 }
76
77 /* called with rcu_read_lock */
78 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
79 {
80         if (should_deliver(to, skb)) {
81                 __br_deliver(to, skb);
82                 return;
83         }
84
85         kfree_skb(skb);
86 }
87
88 /* called with rcu_read_lock */
89 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
90 {
91         if (should_deliver(to, skb)) {
92                 __br_forward(to, skb);
93                 return;
94         }
95
96         kfree_skb(skb);
97 }
98
99 /* called under bridge lock */
100 static void br_flood(struct net_bridge *br, struct sk_buff *skb, int clone,
101         void (*__packet_hook)(const struct net_bridge_port *p, 
102                               struct sk_buff *skb))
103 {
104         struct net_bridge_port *p;
105         struct net_bridge_port *prev;
106
107         if (clone) {
108                 struct sk_buff *skb2;
109
110                 if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
111                         br->statistics.tx_dropped++;
112                         return;
113                 }
114
115                 skb = skb2;
116         }
117
118         prev = NULL;
119
120         list_for_each_entry_rcu(p, &br->port_list, list) {
121                 if (should_deliver(p, skb)) {
122                         if (prev != NULL) {
123                                 struct sk_buff *skb2;
124
125                                 if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
126                                         br->statistics.tx_dropped++;
127                                         kfree_skb(skb);
128                                         return;
129                                 }
130
131                                 __packet_hook(prev, skb2);
132                         }
133
134                         prev = p;
135                 }
136         }
137
138         if (prev != NULL) {
139                 __packet_hook(prev, skb);
140                 return;
141         }
142
143         kfree_skb(skb);
144 }
145
146
147 /* called with rcu_read_lock */
148 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, int clone)
149 {
150         br_flood(br, skb, clone, __br_deliver);
151 }
152
153 /* called under bridge lock */
154 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, int clone)
155 {
156         br_flood(br, skb, clone, __br_forward);
157 }