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1da177e4 LT |
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 | { | |
2a7bc3c9 VD |
34 | /* drop mtu oversized packets except tso */ |
35 | if (skb->len > skb->dev->mtu && !skb_shinfo(skb)->tso_size) | |
1da177e4 LT |
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; | |
1da177e4 LT |
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 | } |