[linux.git] / net / bridge / br_forward.c

/*
 *	Forwarding decision
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<[email protected]>
 *
 *	$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/if_vlan.h>
#include <linux/netfilter_bridge.h>
#include "br_private.h"

/* Don't forward packets to originating port or forwarding diasabled */
static inline int should_deliver(const struct net_bridge_port *p, 
				 const struct sk_buff *skb)
{
	return (skb->dev != p->dev && p->state == BR_STATE_FORWARDING);
}

static inline unsigned packet_length(const struct sk_buff *skb)
{
	return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
}

int br_dev_queue_push_xmit(struct sk_buff *skb)
{
	/* drop mtu oversized packets except gso */
	if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
		kfree_skb(skb);
	else {
		/* ip_refrag calls ip_fragment, doesn't copy the MAC header. */
		if (nf_bridge_maybe_copy_header(skb))
			kfree_skb(skb);
		else {
			skb_push(skb, ETH_HLEN);

			dev_queue_xmit(skb);
		}
	}

	return 0;
}

int br_forward_finish(struct sk_buff *skb)
{
	return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
		       br_dev_queue_push_xmit);

}

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);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Forwarding decision
	3	* Linux ethernet bridge
	4	*
	5	* Authors:
	6	* Lennert Buytenhek <[email protected]>
	7	*
	8	* $Id: br_forward.c,v 1.4 2001/08/14 22:05:57 davem Exp $
	9	*
	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.
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/netdevice.h>
	18	#include <linux/skbuff.h>
85ca719e	19	#include <linux/if_vlan.h>
1da177e4 LT	20	#include <linux/netfilter_bridge.h>
	21	#include "br_private.h"
	22
9ef513be	23	/* Don't forward packets to originating port or forwarding diasabled */
1da177e4 LT	24	static inline int should_deliver(const struct net_bridge_port *p,
	25	const struct sk_buff *skb)
	26	{
9ef513be	27	return (skb->dev != p->dev && p->state == BR_STATE_FORWARDING);
1da177e4 LT	28	}
1da177e4 LT	29
85ca719e SH	30	static inline unsigned packet_length(const struct sk_buff *skb)
	31	{
	32	return skb->len - (skb->protocol == htons(ETH_P_8021Q) ? VLAN_HLEN : 0);
	33	}
	34
1da177e4 LT	35	int br_dev_queue_push_xmit(struct sk_buff *skb)
1da177e4 LT	36	{
7967168c	37	/* drop mtu oversized packets except gso */
89114afd	38	if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb))
1da177e4 LT	39	kfree_skb(skb);
1da177e4 LT	40	else {
1da177e4	41	/* ip_refrag calls ip_fragment, doesn't copy the MAC header. */
3a13813e SH	42	if (nf_bridge_maybe_copy_header(skb))
3a13813e SH	43	kfree_skb(skb);
07317621	44	else {
3a13813e	45	skb_push(skb, ETH_HLEN);
1da177e4	46
3a13813e SH	47	dev_queue_xmit(skb);
3a13813e SH	48	}
1da177e4 LT	49	}
	50
	51	return 0;
	52	}
	53
	54	int br_forward_finish(struct sk_buff *skb)
	55	{
9ef513be SH	56	return NF_HOOK(PF_BRIDGE, NF_BR_POST_ROUTING, skb, NULL, skb->dev,
9ef513be SH	57	br_dev_queue_push_xmit);
1da177e4	58
1da177e4 LT	59	}
	60
	61	static void __br_deliver(const struct net_bridge_port to, struct sk_buff skb)
	62	{
	63	skb->dev = to->dev;
1da177e4 LT	64	NF_HOOK(PF_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,
	65	br_forward_finish);
	66	}
	67
	68	static void __br_forward(const struct net_bridge_port to, struct sk_buff skb)
	69	{
	70	struct net_device *indev;
	71
	72	indev = skb->dev;
	73	skb->dev = to->dev;
	74	skb->ip_summed = CHECKSUM_NONE;
	75
	76	NF_HOOK(PF_BRIDGE, NF_BR_FORWARD, skb, indev, skb->dev,
	77	br_forward_finish);
	78	}
	79
	80	/* called with rcu_read_lock */
	81	void br_deliver(const struct net_bridge_port to, struct sk_buff skb)
	82	{
	83	if (should_deliver(to, skb)) {
	84	__br_deliver(to, skb);
	85	return;
	86	}
	87
	88	kfree_skb(skb);
	89	}
	90
	91	/* called with rcu_read_lock */
	92	void br_forward(const struct net_bridge_port to, struct sk_buff skb)
	93	{
	94	if (should_deliver(to, skb)) {
	95	__br_forward(to, skb);
	96	return;
	97	}
	98
	99	kfree_skb(skb);
	100	}
	101
	102	/* called under bridge lock */
	103	static void br_flood(struct net_bridge br, struct sk_buff skb, int clone,
	104	void (__packet_hook)(const struct net_bridge_port p,
	105	struct sk_buff *skb))
	106	{
	107	struct net_bridge_port *p;
	108	struct net_bridge_port *prev;
	109
	110	if (clone) {
	111	struct sk_buff *skb2;
	112
	113	if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
	114	br->statistics.tx_dropped++;
	115	return;
	116	}
	117
	118	skb = skb2;
	119	}
	120
	121	prev = NULL;
	122
	123	list_for_each_entry_rcu(p, &br->port_list, list) {
	124	if (should_deliver(p, skb)) {
	125	if (prev != NULL) {
	126	struct sk_buff *skb2;
	127
128	if ((skb2 = skb_clone(skb, GFP_ATOMIC)) == NULL) {
129	br->statistics.tx_dropped++;
130	kfree_skb(skb);
131	return;
132	}
133
134	__packet_hook(prev, skb2);
135	}
136
137	prev = p;
138	}
139	}
140
141	if (prev != NULL) {
142	__packet_hook(prev, skb);
143	return;
144	}
145
146	kfree_skb(skb);
147	}
148
149
150	/* called with rcu_read_lock */
151	void br_flood_deliver(struct net_bridge br, struct sk_buff skb, int clone)
152	{
153	br_flood(br, skb, clone, __br_deliver);
154	}
155
156	/* called under bridge lock */
157	void br_flood_forward(struct net_bridge br, struct sk_buff skb, int clone)
158	{
159	br_flood(br, skb, clone, __br_forward);
160	}