blob: ef9f2095f96e37dae664786b70638b46befd88da [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
22static 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
32int br_dev_queue_push_xmit(struct sk_buff *skb)
33{
34 if (skb->len > skb->dev->mtu)
35 kfree_skb(skb);
36 else {
37#ifdef CONFIG_BRIDGE_NETFILTER
38 /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */
39 nf_bridge_maybe_copy_header(skb);
40#endif
41 skb_push(skb, ETH_HLEN);
42
43 dev_queue_xmit(skb);
44 }
45
46 return 0;
47}
48
49int br_forward_finish(struct sk_buff *skb)
50{
51 NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
52 br_dev_queue_push_xmit);
53
54 return 0;
55}
56
57static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
58{
59 skb->dev = to->dev;
60#ifdef CONFIG_NETFILTER_DEBUG
61 skb->nf_debug = 0;
62#endif
63 NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
64 br_forward_finish);
65}
66
67static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
68{
69 struct net_device *indev;
70
71 indev = skb->dev;
72 skb->dev = to->dev;
73 skb->ip_summed = CHECKSUM_NONE;
74
75 NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
76 br_forward_finish);
77}
78
79/* called with rcu_read_lock */
80void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
81{
82 if (should_deliver(to, skb)) {
83 __br_deliver(to, skb);
84 return;
85 }
86
87 kfree_skb(skb);
88}
89
90/* called with rcu_read_lock */
91void br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
92{
93 if (should_deliver(to, skb)) {
94 __br_forward(to, skb);
95 return;
96 }
97
98 kfree_skb(skb);
99}
100
101/* called under bridge lock */
102static void br_flood(struct net_bridge *br, struct sk_buff *skb, int clone,
103 void (*__packet_hook)(const struct net_bridge_port *p,
104 struct sk_buff *skb))
105{
106 struct net_bridge_port *p;
107 struct net_bridge_port *prev;
108
109 if (clone) {
110 struct sk_buff *skb2;
111
112 if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
113 br->statistics.tx_dropped++;
114 return;
115 }
116
117 skb = skb2;
118 }
119
120 prev = NULL;
121
122 list_for_each_entry_rcu(p, &br->port_list, list) {
123 if (should_deliver(p, skb)) {
124 if (prev != NULL) {
125 struct sk_buff *skb2;
126
127 if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
128 br->statistics.tx_dropped++;
129 kfree_skb(skb);
130 return;
131 }
132
133 __packet_hook(prev, skb2);
134 }
135
136 prev = p;
137 }
138 }
139
140 if (prev != NULL) {
141 __packet_hook(prev, skb);
142 return;
143 }
144
145 kfree_skb(skb);
146}
147
148
149/* called with rcu_read_lock */
150void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, int clone)
151{
152 br_flood(br, skb, clone, __br_deliver);
153}
154
155/* called under bridge lock */
156void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, int clone)
157{
158 br_flood(br, skb, clone, __br_forward);
159}