Commit | Line | Data |
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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> | |
85ca719e | 19 | #include <linux/if_vlan.h> |
1da177e4 LT |
20 | #include <linux/netfilter_bridge.h> |
21 | #include "br_private.h" | |
22 | ||
9ef513be | 23 | /* Don't forward packets to originating port or forwarding diasabled */ |
1da177e4 LT |
24 | static inline int should_deliver(const struct net_bridge_port *p, |
25 | const struct sk_buff *skb) | |
26 | { | |
9ef513be | 27 | return (skb->dev != p->dev && p->state == BR_STATE_FORWARDING); |
1da177e4 LT |
28 | } |
29 | ||
85ca719e SH |
30 | static inline unsigned packet_length(const struct sk_buff *skb) |
31 | { | |
32 | return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
33 | } | |
34 | ||
1da177e4 LT |
35 | int br_dev_queue_push_xmit(struct sk_buff *skb) |
36 | { | |
2a7bc3c9 | 37 | /* drop mtu oversized packets except tso */ |
85ca719e | 38 | if (packet_length(skb) > skb->dev->mtu && !skb_shinfo(skb)->tso_size) |
1da177e4 LT |
39 | kfree_skb(skb); |
40 | else { | |
41 | #ifdef CONFIG_BRIDGE_NETFILTER | |
42 | /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */ | |
43 | nf_bridge_maybe_copy_header(skb); | |
44 | #endif | |
45 | skb_push(skb, ETH_HLEN); | |
46 | ||
47 | dev_queue_xmit(skb); | |
48 | } | |
49 | ||
50 | return 0; | |
51 | } | |
52 | ||
53 | int br_forward_finish(struct sk_buff *skb) | |
54 | { | |
9ef513be SH |
55 | return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, |
56 | br_dev_queue_push_xmit); | |
1da177e4 | 57 | |
1da177e4 LT |
58 | } |
59 | ||
60 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
61 | { | |
62 | skb->dev = to->dev; | |
1da177e4 LT |
63 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
64 | br_forward_finish); | |
65 | } | |
66 | ||
67 | static 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 */ | |
80 | void 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 */ | |
91 | void 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 */ | |
102 | static 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 */ | |
150 | void 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 */ | |
156 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, int clone) | |
157 | { | |
158 | br_flood(br, skb, clone, __br_forward); | |
159 | } |