Revert "[PATCH] paravirt: Add startup infrastructure for paravirtualization"
[pv_ops_mirror.git] / net / bridge / br_input.c
blob420bbb9955e93fa2480393292e7b2705d1cc7a28
1 /*
2 * Handle incoming frames
3 * Linux ethernet bridge
5 * Authors:
6 * Lennert Buytenhek <buytenh@gnu.org>
8 * $Id: br_input.c,v 1.10 2001/12/24 04:50:20 davem Exp $
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.
16 #include <linux/kernel.h>
17 #include <linux/netdevice.h>
18 #include <linux/etherdevice.h>
19 #include <linux/netfilter_bridge.h>
20 #include "br_private.h"
22 /* Bridge group multicast address 802.1d (pg 51). */
23 const u8 br_group_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
25 static void br_pass_frame_up(struct net_bridge *br, struct sk_buff *skb)
27 struct net_device *indev;
29 br->statistics.rx_packets++;
30 br->statistics.rx_bytes += skb->len;
32 indev = skb->dev;
33 skb->dev = br->dev;
35 NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, indev, NULL,
36 netif_receive_skb);
39 /* note: already called with rcu_read_lock (preempt_disabled) */
40 int br_handle_frame_finish(struct sk_buff *skb)
42 const unsigned char *dest = eth_hdr(skb)->h_dest;
43 struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
44 struct net_bridge *br;
45 struct net_bridge_fdb_entry *dst;
46 int passedup = 0;
48 if (!p || p->state == BR_STATE_DISABLED)
49 goto drop;
51 /* insert into forwarding database after filtering to avoid spoofing */
52 br = p->br;
53 br_fdb_update(br, p, eth_hdr(skb)->h_source);
55 if (p->state == BR_STATE_LEARNING)
56 goto drop;
58 if (br->dev->flags & IFF_PROMISC) {
59 struct sk_buff *skb2;
61 skb2 = skb_clone(skb, GFP_ATOMIC);
62 if (skb2 != NULL) {
63 passedup = 1;
64 br_pass_frame_up(br, skb2);
68 if (is_multicast_ether_addr(dest)) {
69 br->statistics.multicast++;
70 br_flood_forward(br, skb, !passedup);
71 if (!passedup)
72 br_pass_frame_up(br, skb);
73 goto out;
76 dst = __br_fdb_get(br, dest);
77 if (dst != NULL && dst->is_local) {
78 if (!passedup)
79 br_pass_frame_up(br, skb);
80 else
81 kfree_skb(skb);
82 goto out;
85 if (dst != NULL) {
86 br_forward(dst->dst, skb);
87 goto out;
90 br_flood_forward(br, skb, 0);
92 out:
93 return 0;
94 drop:
95 kfree_skb(skb);
96 goto out;
99 /* note: already called with rcu_read_lock (preempt_disabled) */
100 static int br_handle_local_finish(struct sk_buff *skb)
102 struct net_bridge_port *p = rcu_dereference(skb->dev->br_port);
104 if (p && p->state != BR_STATE_DISABLED)
105 br_fdb_update(p->br, p, eth_hdr(skb)->h_source);
107 return 0; /* process further */
110 /* Does address match the link local multicast address.
111 * 01:80:c2:00:00:0X
113 static inline int is_link_local(const unsigned char *dest)
115 const u16 *a = (const u16 *) dest;
116 static const u16 *const b = (const u16 *const ) br_group_address;
117 static const u16 m = __constant_cpu_to_be16(0xfff0);
119 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
123 * Called via br_handle_frame_hook.
124 * Return NULL if skb is handled
125 * note: already called with rcu_read_lock (preempt_disabled)
127 struct sk_buff *br_handle_frame(struct net_bridge_port *p, struct sk_buff *skb)
129 const unsigned char *dest = eth_hdr(skb)->h_dest;
131 if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
132 goto drop;
134 if (unlikely(is_link_local(dest))) {
135 /* Pause frames shouldn't be passed up by driver anyway */
136 if (skb->protocol == htons(ETH_P_PAUSE))
137 goto drop;
139 /* Process STP BPDU's through normal netif_receive_skb() path */
140 if (p->br->stp_enabled != BR_NO_STP) {
141 if (NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_IN, skb, skb->dev,
142 NULL, br_handle_local_finish))
143 return NULL;
144 else
145 return skb;
149 switch (p->state) {
150 case BR_STATE_FORWARDING:
152 if (br_should_route_hook) {
153 if (br_should_route_hook(&skb))
154 return skb;
155 dest = eth_hdr(skb)->h_dest;
157 /* fall through */
158 case BR_STATE_LEARNING:
159 if (!compare_ether_addr(p->br->dev->dev_addr, dest))
160 skb->pkt_type = PACKET_HOST;
162 NF_HOOK(PF_BRIDGE, NF_BR_PRE_ROUTING, skb, skb->dev, NULL,
163 br_handle_frame_finish);
164 break;
165 default:
166 drop:
167 kfree_skb(skb);
169 return NULL;