3 * Linux ethernet bridge
6 * Lennert Buytenhek <buytenh@gnu.org>
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.
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <linux/kernel.h>
17 #include <linux/netdevice.h>
18 #include <linux/skbuff.h>
19 #include <linux/if_vlan.h>
20 #include <linux/netfilter_bridge.h>
21 #include "br_private.h"
23 static int deliver_clone(const struct net_bridge_port
*prev
,
25 void (*__packet_hook
)(const struct net_bridge_port
*p
,
26 struct sk_buff
*skb
));
28 /* Don't forward packets to originating port or forwarding diasabled */
29 static inline int should_deliver(const struct net_bridge_port
*p
,
30 const struct sk_buff
*skb
)
32 return (((p
->flags
& BR_HAIRPIN_MODE
) || skb
->dev
!= p
->dev
) &&
33 p
->state
== BR_STATE_FORWARDING
);
36 static inline unsigned packet_length(const struct sk_buff
*skb
)
38 return skb
->len
- (skb
->protocol
== htons(ETH_P_8021Q
) ? VLAN_HLEN
: 0);
41 int br_dev_queue_push_xmit(struct sk_buff
*skb
)
43 /* drop mtu oversized packets except gso */
44 if (packet_length(skb
) > skb
->dev
->mtu
&& !skb_is_gso(skb
))
47 /* ip_refrag calls ip_fragment, doesn't copy the MAC header. */
48 if (nf_bridge_maybe_copy_header(skb
))
51 skb_push(skb
, ETH_HLEN
);
60 int br_forward_finish(struct sk_buff
*skb
)
62 return NF_HOOK(PF_BRIDGE
, NF_BR_POST_ROUTING
, skb
, NULL
, skb
->dev
,
63 br_dev_queue_push_xmit
);
67 static void __br_deliver(const struct net_bridge_port
*to
, struct sk_buff
*skb
)
70 NF_HOOK(PF_BRIDGE
, NF_BR_LOCAL_OUT
, skb
, NULL
, skb
->dev
,
74 static void __br_forward(const struct net_bridge_port
*to
, struct sk_buff
*skb
)
76 struct net_device
*indev
;
78 if (skb_warn_if_lro(skb
)) {
85 skb_forward_csum(skb
);
87 NF_HOOK(PF_BRIDGE
, NF_BR_FORWARD
, skb
, indev
, skb
->dev
,
91 /* called with rcu_read_lock */
92 void br_deliver(const struct net_bridge_port
*to
, struct sk_buff
*skb
)
94 if (should_deliver(to
, skb
)) {
95 __br_deliver(to
, skb
);
102 /* called with rcu_read_lock */
103 void br_forward(const struct net_bridge_port
*to
, struct sk_buff
*skb
, struct sk_buff
*skb0
)
105 if (should_deliver(to
, skb
)) {
107 deliver_clone(to
, skb
, __br_forward
);
109 __br_forward(to
, skb
);
117 static int deliver_clone(const struct net_bridge_port
*prev
,
119 void (*__packet_hook
)(const struct net_bridge_port
*p
,
120 struct sk_buff
*skb
))
122 skb
= skb_clone(skb
, GFP_ATOMIC
);
124 struct net_device
*dev
= BR_INPUT_SKB_CB(skb
)->brdev
;
126 dev
->stats
.tx_dropped
++;
130 __packet_hook(prev
, skb
);
134 static struct net_bridge_port
*maybe_deliver(
135 struct net_bridge_port
*prev
, struct net_bridge_port
*p
,
137 void (*__packet_hook
)(const struct net_bridge_port
*p
,
138 struct sk_buff
*skb
))
142 if (!should_deliver(p
, skb
))
148 err
= deliver_clone(prev
, skb
, __packet_hook
);
156 /* called under bridge lock */
157 static void br_flood(struct net_bridge
*br
, struct sk_buff
*skb
,
158 struct sk_buff
*skb0
,
159 void (*__packet_hook
)(const struct net_bridge_port
*p
,
160 struct sk_buff
*skb
))
162 struct net_bridge_port
*p
;
163 struct net_bridge_port
*prev
;
167 list_for_each_entry_rcu(p
, &br
->port_list
, list
) {
168 prev
= maybe_deliver(prev
, p
, skb
, __packet_hook
);
177 deliver_clone(prev
, skb
, __packet_hook
);
179 __packet_hook(prev
, skb
);
188 /* called with rcu_read_lock */
189 void br_flood_deliver(struct net_bridge
*br
, struct sk_buff
*skb
)
191 br_flood(br
, skb
, NULL
, __br_deliver
);
194 /* called under bridge lock */
195 void br_flood_forward(struct net_bridge
*br
, struct sk_buff
*skb
,
196 struct sk_buff
*skb2
)
198 br_flood(br
, skb
, skb2
, __br_forward
);
201 #ifdef CONFIG_BRIDGE_IGMP_SNOOPING
202 /* called with rcu_read_lock */
203 static void br_multicast_flood(struct net_bridge_mdb_entry
*mdst
,
204 struct sk_buff
*skb
, struct sk_buff
*skb0
,
205 void (*__packet_hook
)(
206 const struct net_bridge_port
*p
,
207 struct sk_buff
*skb
))
209 struct net_device
*dev
= BR_INPUT_SKB_CB(skb
)->brdev
;
210 struct net_bridge
*br
= netdev_priv(dev
);
211 struct net_bridge_port
*port
;
212 struct net_bridge_port
*lport
, *rport
;
213 struct net_bridge_port
*prev
;
214 struct net_bridge_port_group
*p
;
215 struct hlist_node
*rp
;
219 rp
= br
->router_list
.first
;
220 p
= mdst
? mdst
->ports
: NULL
;
222 lport
= p
? p
->port
: NULL
;
223 rport
= rp
? hlist_entry(rp
, struct net_bridge_port
, rlist
) :
226 port
= (unsigned long)lport
> (unsigned long)rport
?
229 prev
= maybe_deliver(prev
, port
, skb
, __packet_hook
);
233 if ((unsigned long)lport
>= (unsigned long)port
)
235 if ((unsigned long)rport
>= (unsigned long)port
)
243 deliver_clone(prev
, skb
, __packet_hook
);
245 __packet_hook(prev
, skb
);
253 /* called with rcu_read_lock */
254 void br_multicast_deliver(struct net_bridge_mdb_entry
*mdst
,
257 br_multicast_flood(mdst
, skb
, NULL
, __br_deliver
);
260 /* called with rcu_read_lock */
261 void br_multicast_forward(struct net_bridge_mdb_entry
*mdst
,
262 struct sk_buff
*skb
, struct sk_buff
*skb2
)
264 br_multicast_flood(mdst
, skb
, skb2
, __br_forward
);