158 lines
3.2 KiB
C
158 lines
3.2 KiB
C
/*
|
|
* Forwarding decision
|
|
* Linux ethernet bridge
|
|
*
|
|
* Authors:
|
|
* Lennert Buytenhek <buytenh@gnu.org>
|
|
*
|
|
* $Id: br_forward.c,v 1.4 2001/08/14 22:05:57 davem Exp $
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/netfilter_bridge.h>
|
|
#include "br_private.h"
|
|
|
|
static inline int should_deliver(const struct net_bridge_port *p,
|
|
const struct sk_buff *skb)
|
|
{
|
|
if (skb->dev == p->dev ||
|
|
p->state != BR_STATE_FORWARDING)
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int br_dev_queue_push_xmit(struct sk_buff *skb)
|
|
{
|
|
/* drop mtu oversized packets except tso */
|
|
if (skb->len > skb->dev->mtu && !skb_shinfo(skb)->tso_size)
|
|
kfree_skb(skb);
|
|
else {
|
|
#ifdef CONFIG_BRIDGE_NETFILTER
|
|
/* ip_refrag calls ip_fragment, doesn't copy the MAC header. */
|
|
nf_bridge_maybe_copy_header(skb);
|
|
#endif
|
|
skb_push(skb, ETH_HLEN);
|
|
|
|
dev_queue_xmit(skb);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int br_forward_finish(struct sk_buff *skb)
|
|
{
|
|
NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
|
|
br_dev_queue_push_xmit);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
|
|
{
|
|
skb->dev = to->dev;
|
|
NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
|
|
br_forward_finish);
|
|
}
|
|
|
|
static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
|
|
{
|
|
struct net_device *indev;
|
|
|
|
indev = skb->dev;
|
|
skb->dev = to->dev;
|
|
skb->ip_summed = CHECKSUM_NONE;
|
|
|
|
NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
|
|
br_forward_finish);
|
|
}
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
|
|
{
|
|
if (should_deliver(to, skb)) {
|
|
__br_deliver(to, skb);
|
|
return;
|
|
}
|
|
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
|
|
{
|
|
if (should_deliver(to, skb)) {
|
|
__br_forward(to, skb);
|
|
return;
|
|
}
|
|
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
/* called under bridge lock */
|
|
static void br_flood(struct net_bridge *br, struct sk_buff *skb, int clone,
|
|
void (*__packet_hook)(const struct net_bridge_port *p,
|
|
struct sk_buff *skb))
|
|
{
|
|
struct net_bridge_port *p;
|
|
struct net_bridge_port *prev;
|
|
|
|
if (clone) {
|
|
struct sk_buff *skb2;
|
|
|
|
if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
|
|
br->statistics.tx_dropped++;
|
|
return;
|
|
}
|
|
|
|
skb = skb2;
|
|
}
|
|
|
|
prev = NULL;
|
|
|
|
list_for_each_entry_rcu(p, &br->port_list, list) {
|
|
if (should_deliver(p, skb)) {
|
|
if (prev != NULL) {
|
|
struct sk_buff *skb2;
|
|
|
|
if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
|
|
br->statistics.tx_dropped++;
|
|
kfree_skb(skb);
|
|
return;
|
|
}
|
|
|
|
__packet_hook(prev, skb2);
|
|
}
|
|
|
|
prev = p;
|
|
}
|
|
}
|
|
|
|
if (prev != NULL) {
|
|
__packet_hook(prev, skb);
|
|
return;
|
|
}
|
|
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
|
|
/* called with rcu_read_lock */
|
|
void br_flood_deliver(struct net_bridge *br, struct sk_buff *skb, int clone)
|
|
{
|
|
br_flood(br, skb, clone, __br_deliver);
|
|
}
|
|
|
|
/* called under bridge lock */
|
|
void br_flood_forward(struct net_bridge *br, struct sk_buff *skb, int clone)
|
|
{
|
|
br_flood(br, skb, clone, __br_forward);
|
|
}
|