tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
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 /* 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
50int 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
58static 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
65static 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 */
78void 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 */
89void 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 */
100static 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 */
148void 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 */
154void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, int clone)
155{
156 br_flood(br, skb, clone, __br_forward);
157}