net/bridge: use kobject_put to release kobject in br_add_if error path
[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  *      This program is free software; you can redistribute it and/or
9  *      modify it under the terms of the GNU General Public License
10  *      as published by the Free Software Foundation; either version
11  *      2 of the License, or (at your option) any later version.
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/netdevice.h>
16 #include <linux/skbuff.h>
17 #include <linux/if_vlan.h>
18 #include <linux/netfilter_bridge.h>
19 #include "br_private.h"
20
21 /* Don't forward packets to originating port or forwarding diasabled */
22 static inline int should_deliver(const struct net_bridge_port *p,
23                                  const struct sk_buff *skb)
24 {
25         return (skb->dev != p->dev && p->state == BR_STATE_FORWARDING);
26 }
27
28 static inline unsigned packet_length(const struct sk_buff *skb)
29 {
30         return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
31 }
32
33 int br_dev_queue_push_xmit(struct sk_buff *skb)
34 {
35         /* drop mtu oversized packets except gso */
36         if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
37                 kfree_skb(skb);
38         else {
39                 /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */
40                 if (nf_bridge_maybe_copy_header(skb))
41                         kfree_skb(skb);
42                 else {
43                         skb_push(skb, ETH_HLEN);
44
45                         dev_queue_xmit(skb);
46                 }
47         }
48
49         return 0;
50 }
51
52 int br_forward_finish(struct sk_buff *skb)
53 {
54         return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
55                        br_dev_queue_push_xmit);
56
57 }
58
59 static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
60 {
61         skb->dev = to->dev;
62         NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
63                         br_forward_finish);
64 }
65
66 static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
67 {
68         struct net_device *indev;
69
70         if (skb_warn_if_lro(skb)) {
71                 kfree_skb(skb);
72                 return;
73         }
74
75         indev = skb->dev;
76         skb->dev = to->dev;
77         skb_forward_csum(skb);
78
79         NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
80                         br_forward_finish);
81 }
82
83 /* called with rcu_read_lock */
84 void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
85 {
86         if (should_deliver(to, skb)) {
87                 __br_deliver(to, skb);
88                 return;
89         }
90
91         kfree_skb(skb);
92 }
93
94 /* called with rcu_read_lock */
95 void br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
96 {
97         if (should_deliver(to, skb)) {
98                 __br_forward(to, skb);
99                 return;
100         }
101
102         kfree_skb(skb);
103 }
104
105 /* called under bridge lock */
106 static void br_flood(struct net_bridge *br, struct sk_buff *skb,
107         void (*__packet_hook)(const struct net_bridge_port *p,
108                               struct sk_buff *skb))
109 {
110         struct net_bridge_port *p;
111         struct net_bridge_port *prev;
112
113         prev = NULL;
114
115         list_for_each_entry_rcu(p, &br->port_list, list) {
116                 if (should_deliver(p, skb)) {
117                         if (prev != NULL) {
118                                 struct sk_buff *skb2;
119
120                                 if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
121                                         br->dev->stats.tx_dropped++;
122                                         kfree_skb(skb);
123                                         return;
124                                 }
125
126                                 __packet_hook(prev, skb2);
127                         }
128
129                         prev = p;
130                 }
131         }
132
133         if (prev != NULL) {
134                 __packet_hook(prev, skb);
135                 return;
136         }
137
138         kfree_skb(skb);
139 }
140
141
142 /* called with rcu_read_lock */
143 void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb)
144 {
145         br_flood(br, skb, __br_deliver);
146 }
147
148 /* called under bridge lock */
149 void br_flood_forward(struct net_bridge *br, struct sk_buff *skb)
150 {
151         br_flood(br, skb, __br_forward);
152 }