2 * Handle incoming frames
3 * Linux ethernet bridge
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
;
35 NF_HOOK(PF_BRIDGE
, NF_BR_LOCAL_IN
, skb
, indev
, NULL
,
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
;
48 if (!p
|| p
->state
== BR_STATE_DISABLED
)
51 /* insert into forwarding database after filtering to avoid spoofing */
53 br_fdb_update(br
, p
, eth_hdr(skb
)->h_source
);
55 if (p
->state
== BR_STATE_LEARNING
)
58 if (br
->dev
->flags
& IFF_PROMISC
) {
61 skb2
= skb_clone(skb
, GFP_ATOMIC
);
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
);
72 br_pass_frame_up(br
, skb
);
76 dst
= __br_fdb_get(br
, dest
);
77 if (dst
!= NULL
&& dst
->is_local
) {
79 br_pass_frame_up(br
, skb
);
86 br_forward(dst
->dst
, skb
);
90 br_flood_forward(br
, skb
, 0);
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.
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
))
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
))
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
))
150 case BR_STATE_FORWARDING
:
152 if (br_should_route_hook
) {
153 if (br_should_route_hook(&skb
))
155 dest
= eth_hdr(skb
)->h_dest
;
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
);