Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Forwarding decision | |
3 | * Linux ethernet bridge | |
4 | * | |
5 | * Authors: | |
6 | * Lennert Buytenhek <buytenh@gnu.org> | |
7 | * | |
1da177e4 LT |
8 | * This program is free software; you can redistribute it and/or |
9 | * modify it under the terms of the GNU General Public License | |
10 | * as published by the Free Software Foundation; either version | |
11 | * 2 of the License, or (at your option) any later version. | |
12 | */ | |
13 | ||
14 | #include <linux/kernel.h> | |
15 | #include <linux/netdevice.h> | |
16 | #include <linux/skbuff.h> | |
85ca719e | 17 | #include <linux/if_vlan.h> |
1da177e4 LT |
18 | #include <linux/netfilter_bridge.h> |
19 | #include "br_private.h" | |
20 | ||
9ef513be | 21 | /* Don't forward packets to originating port or forwarding diasabled */ |
9d6f229f | 22 | static inline int should_deliver(const struct net_bridge_port *p, |
1da177e4 LT |
23 | const struct sk_buff *skb) |
24 | { | |
9ef513be | 25 | return (skb->dev != p->dev && p->state == BR_STATE_FORWARDING); |
1da177e4 LT |
26 | } |
27 | ||
85ca719e SH |
28 | static inline unsigned packet_length(const struct sk_buff *skb) |
29 | { | |
30 | return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0); | |
31 | } | |
32 | ||
1da177e4 LT |
33 | int br_dev_queue_push_xmit(struct sk_buff *skb) |
34 | { | |
7967168c | 35 | /* drop mtu oversized packets except gso */ |
89114afd | 36 | if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) |
1da177e4 LT |
37 | kfree_skb(skb); |
38 | else { | |
1da177e4 | 39 | /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */ |
3a13813e SH |
40 | if (nf_bridge_maybe_copy_header(skb)) |
41 | kfree_skb(skb); | |
07317621 | 42 | else { |
3a13813e | 43 | skb_push(skb, ETH_HLEN); |
1da177e4 | 44 | |
3a13813e SH |
45 | dev_queue_xmit(skb); |
46 | } | |
1da177e4 LT |
47 | } |
48 | ||
49 | return 0; | |
50 | } | |
51 | ||
52 | int br_forward_finish(struct sk_buff *skb) | |
53 | { | |
9ef513be SH |
54 | return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev, |
55 | br_dev_queue_push_xmit); | |
1da177e4 | 56 | |
1da177e4 LT |
57 | } |
58 | ||
59 | static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
60 | { | |
61 | skb->dev = to->dev; | |
1da177e4 LT |
62 | NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev, |
63 | br_forward_finish); | |
64 | } | |
65 | ||
66 | static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
67 | { | |
68 | struct net_device *indev; | |
69 | ||
70 | indev = skb->dev; | |
71 | skb->dev = to->dev; | |
35fc92a9 | 72 | skb_forward_csum(skb); |
1da177e4 LT |
73 | |
74 | NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev, | |
75 | br_forward_finish); | |
76 | } | |
77 | ||
78 | /* called with rcu_read_lock */ | |
79 | void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) | |
80 | { | |
81 | if (should_deliver(to, skb)) { | |
82 | __br_deliver(to, skb); | |
83 | return; | |
84 | } | |
85 | ||
86 | kfree_skb(skb); | |
87 | } | |
88 | ||
89 | /* called with rcu_read_lock */ | |
90 | void br_forward(const struct net_bridge_port *to, struct sk_buff *skb) | |
91 | { | |
92 | if (should_deliver(to, skb)) { | |
93 | __br_forward(to, skb); | |
94 | return; | |
95 | } | |
96 | ||
97 | kfree_skb(skb); | |
98 | } | |
99 | ||
100 | /* called under bridge lock */ | |
e081e1e3 | 101 | static void br_flood(struct net_bridge *br, struct sk_buff *skb, |
9d6f229f | 102 | void (*__packet_hook)(const struct net_bridge_port *p, |
1da177e4 LT |
103 | struct sk_buff *skb)) |
104 | { | |
105 | struct net_bridge_port *p; | |
106 | struct net_bridge_port *prev; | |
107 | ||
1da177e4 LT |
108 | prev = NULL; |
109 | ||
110 | list_for_each_entry_rcu(p, &br->port_list, list) { | |
111 | if (should_deliver(p, skb)) { | |
112 | if (prev != NULL) { | |
113 | struct sk_buff *skb2; | |
114 | ||
115 | if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) { | |
a339f1c8 | 116 | br->dev->stats.tx_dropped++; |
1da177e4 LT |
117 | kfree_skb(skb); |
118 | return; | |
119 | } | |
120 | ||
121 | __packet_hook(prev, skb2); | |
122 | } | |
123 | ||
124 | prev = p; | |
125 | } | |
126 | } | |
127 | ||
128 | if (prev != NULL) { | |
129 | __packet_hook(prev, skb); | |
130 | return; | |
131 | } | |
132 | ||
133 | kfree_skb(skb); | |
134 | } | |
135 | ||
136 | ||
137 | /* called with rcu_read_lock */ | |
e081e1e3 | 138 | void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 139 | { |
e081e1e3 | 140 | br_flood(br, skb, __br_deliver); |
1da177e4 LT |
141 | } |
142 | ||
143 | /* called under bridge lock */ | |
e081e1e3 | 144 | void br_flood_forward(struct net_bridge *br, struct sk_buff *skb) |
1da177e4 | 145 | { |
e081e1e3 | 146 | br_flood(br, skb, __br_forward); |
1da177e4 | 147 | } |