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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 | ||
23 | static inline int should_deliver(const struct net_bridge_port *p, | |
24 | const struct sk_buff *skb) | |
25 | { | |
26 | if (skb->dev == p->dev || | |
27 | p->state != BR_STATE_FORWARDING) | |
28 | return 0; | |
29 | ||
30 | return 1; | |
31 | } | |
32 | ||
85ca719e SH |
33 | static inline unsigned packet_length(const struct sk_buff *skb) |
34 | { | |
35 | return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
36 | } | |
37 | ||
1da177e4 LT |
38 | int br_dev_queue_push_xmit(struct sk_buff *skb) |
39 | { | |
2a7bc3c9 | 40 | /* drop mtu oversized packets except tso */ |
85ca719e | 41 | if (packet_length(skb) > skb->dev->mtu && !skb_shinfo(skb)->tso_size) |
1da177e4 LT |
42 | kfree_skb(skb); |
43 | else { | |
44 | #ifdef CONFIG_BRIDGE_NETFILTER | |
45 | /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */ | |
46 | nf_bridge_maybe_copy_header(skb); | |
47 | #endif | |
48 | skb_push(skb, ETH_HLEN); | |
49 | ||
50 | dev_queue_xmit(skb); | |
51 | } | |
52 | ||
53 | return 0; | |
54 | } | |
55 | ||
56 | int br_forward_finish(struct sk_buff *skb) | |
57 | { | |
58 | NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, | |
59 | br_dev_queue_push_xmit); | |
60 | ||
61 | return 0; | |
62 | } | |
63 | ||
64 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
65 | { | |
66 | skb->dev = to->dev; | |
1da177e4 LT |
67 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
68 | br_forward_finish); | |
69 | } | |
70 | ||
71 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
72 | { | |
73 | struct net_device *indev; | |
74 | ||
75 | indev = skb->dev; | |
76 | skb->dev = to->dev; | |
77 | skb->ip_summed = CHECKSUM_NONE; | |
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, int clone, | |
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 | if (clone) { | |
114 | struct sk_buff *skb2; | |
115 | ||
116 | if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) { | |
117 | br->statistics.tx_dropped++; | |
118 | return; | |
119 | } | |
120 | ||
121 | skb = skb2; | |
122 | } | |
123 | ||
124 | prev = NULL; | |
125 | ||
126 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
127 | if (should_deliver(p, skb)) { | |
128 | if (prev != NULL) { | |
129 | struct sk_buff *skb2; | |
130 | ||
131 | if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) { | |
132 | br->statistics.tx_dropped++; | |
133 | kfree_skb(skb); | |
134 | return; | |
135 | } | |
136 | ||
137 | __packet_hook(prev, skb2); | |
138 | } | |
139 | ||
140 | prev = p; | |
141 | } | |
142 | } | |
143 | ||
144 | if (prev != NULL) { | |
145 | __packet_hook(prev, skb); | |
146 | return; | |
147 | } | |
148 | ||
149 | kfree_skb(skb); | |
150 | } | |
151 | ||
152 | ||
153 | /* called with rcu_read_lock */ | |
154 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, int clone) | |
155 | { | |
156 | br_flood(br, skb, clone, __br_deliver); | |
157 | } | |
158 | ||
159 | /* called under bridge lock */ | |
160 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, int clone) | |
161 | { | |
162 | br_flood(br, skb, clone, __br_forward); | |
163 | } |