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 */ |
9d6f229f | 24 | static inline int should_deliver(const struct net_bridge_port *p, |
1da177e4 LT |
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 | { | |
7967168c | 37 | /* drop mtu oversized packets except gso */ |
89114afd | 38 | if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) |
1da177e4 LT |
39 | kfree_skb(skb); |
40 | else { | |
1da177e4 | 41 | /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */ |
3a13813e SH |
42 | if (nf_bridge_maybe_copy_header(skb)) |
43 | kfree_skb(skb); | |
07317621 | 44 | else { |
3a13813e | 45 | skb_push(skb, ETH_HLEN); |
1da177e4 | 46 | |
3a13813e SH |
47 | dev_queue_xmit(skb); |
48 | } | |
1da177e4 LT |
49 | } |
50 | ||
51 | return 0; | |
52 | } | |
53 | ||
54 | int br_forward_finish(struct sk_buff *skb) | |
55 | { | |
9ef513be SH |
56 | return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, |
57 | br_dev_queue_push_xmit); | |
1da177e4 | 58 | |
1da177e4 LT |
59 | } |
60 | ||
61 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
62 | { | |
63 | skb->dev = to->dev; | |
1da177e4 LT |
64 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
65 | br_forward_finish); | |
66 | } | |
67 | ||
68 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
69 | { | |
70 | struct net_device *indev; | |
71 | ||
72 | indev = skb->dev; | |
73 | skb->dev = to->dev; | |
35fc92a9 | 74 | skb_forward_csum(skb); |
1da177e4 LT |
75 | |
76 | NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev, | |
77 | br_forward_finish); | |
78 | } | |
79 | ||
80 | /* called with rcu_read_lock */ | |
81 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
82 | { | |
83 | if (should_deliver(to, skb)) { | |
84 | __br_deliver(to, skb); | |
85 | return; | |
86 | } | |
87 | ||
88 | kfree_skb(skb); | |
89 | } | |
90 | ||
91 | /* called with rcu_read_lock */ | |
92 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
93 | { | |
94 | if (should_deliver(to, skb)) { | |
95 | __br_forward(to, skb); | |
96 | return; | |
97 | } | |
98 | ||
99 | kfree_skb(skb); | |
100 | } | |
101 | ||
102 | /* called under bridge lock */ | |
e081e1e3 | 103 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
9d6f229f | 104 | void (*__packet_hook)(const struct net_bridge_port *p, |
1da177e4 LT |
105 | struct sk_buff *skb)) |
106 | { | |
107 | struct net_bridge_port *p; | |
108 | struct net_bridge_port *prev; | |
109 | ||
1da177e4 LT |
110 | prev = NULL; |
111 | ||
112 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
113 | if (should_deliver(p, skb)) { | |
114 | if (prev != NULL) { | |
115 | struct sk_buff *skb2; | |
116 | ||
117 | if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) { | |
118 | br->statistics.tx_dropped++; | |
119 | kfree_skb(skb); | |
120 | return; | |
121 | } | |
122 | ||
123 | __packet_hook(prev, skb2); | |
124 | } | |
125 | ||
126 | prev = p; | |
127 | } | |
128 | } | |
129 | ||
130 | if (prev != NULL) { | |
131 | __packet_hook(prev, skb); | |
132 | return; | |
133 | } | |
134 | ||
135 | kfree_skb(skb); | |
136 | } | |
137 | ||
138 | ||
139 | /* called with rcu_read_lock */ | |
e081e1e3 | 140 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 141 | { |
e081e1e3 | 142 | br_flood(br, skb, __br_deliver); |
1da177e4 LT |
143 | } |
144 | ||
145 | /* called under bridge lock */ | |
e081e1e3 | 146 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 147 | { |
e081e1e3 | 148 | br_flood(br, skb, __br_forward); |
1da177e4 | 149 | } |