[deliverable/linux.git] / net / xfrm / xfrm_output.c

/*
 * xfrm_output.c - Common IPsec encapsulation code.
 *
 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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/errno.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <net/dst.h>
#include <net/xfrm.h>

static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
		- skb_headroom(skb);

	if (nhead > 0)
		return pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);

	/* Check tail too... */
	return 0;
}

static int xfrm_state_check(struct xfrm_state *x, struct sk_buff *skb)
{
	int err = xfrm_state_check_expire(x);
	if (err < 0)
		goto err;
	err = xfrm_state_check_space(x, skb);
err:
	return err;
}

static int xfrm_output_one(struct sk_buff *skb)
{
	struct dst_entry *dst = skb->dst;
	struct xfrm_state *x = dst->xfrm;
	int err;

	if (skb->ip_summed == CHECKSUM_PARTIAL) {
		err = skb_checksum_help(skb);
		if (err)
			goto error_nolock;
	}

	do {
		err = x->outer_mode->output(x, skb);
		if (err)
			goto error;

		spin_lock_bh(&x->lock);
		err = xfrm_state_check(x, skb);
		if (err)
			goto error;

		if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
			XFRM_SKB_CB(skb)->seq = ++x->replay.oseq;
			if (xfrm_aevent_is_on())
				xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
		}

		x->curlft.bytes += skb->len;
		x->curlft.packets++;

		spin_unlock_bh(&x->lock);

		err = x->type->output(x, skb);
		if (err)
			goto error_nolock;

		if (!(skb->dst = dst_pop(dst))) {
			err = -EHOSTUNREACH;
			goto error_nolock;
		}
		dst = skb->dst;
		x = dst->xfrm;
	} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));

	err = 0;

out_exit:
	return err;
error:
	spin_unlock_bh(&x->lock);
error_nolock:
	kfree_skb(skb);
	goto out_exit;
}

static int xfrm_output2(struct sk_buff *skb)
{
	int err;

	while (likely((err = xfrm_output_one(skb)) == 0)) {
		struct xfrm_state *x;

		nf_reset(skb);

		err = skb->dst->ops->local_out(skb);
		if (unlikely(err != 1))
			break;

		x = skb->dst->xfrm;
		if (!x)
			return dst_output(skb);

		err = nf_hook(x->inner_mode->afinfo->family,
			      x->inner_mode->afinfo->nf_post_routing, skb,
			      NULL, skb->dst->dev, xfrm_output2);
		if (unlikely(err != 1))
			break;
	}

	return err;
}

int xfrm_output(struct sk_buff *skb)
{
	struct sk_buff *segs;

	if (!skb_is_gso(skb))
		return xfrm_output2(skb);

	segs = skb_gso_segment(skb, 0);
	kfree_skb(skb);
	if (unlikely(IS_ERR(segs)))
		return PTR_ERR(segs);

	do {
		struct sk_buff *nskb = segs->next;
		int err;

		segs->next = NULL;
		err = xfrm_output2(segs);

		if (unlikely(err)) {
			while ((segs = nskb)) {
				nskb = segs->next;
				segs->next = NULL;
				kfree_skb(segs);
			}
			return err;
		}

		segs = nskb;
	} while (segs);

	return 0;
}
EXPORT_SYMBOL_GPL(xfrm_output);
Commit	Line	Data
406ef77c HX	1	/*
	2	* xfrm_output.c - Common IPsec encapsulation code.
	3	*
	4	* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/errno.h>
	13	#include <linux/module.h>
	14	#include <linux/netdevice.h>
862b82c6	15	#include <linux/netfilter.h>
406ef77c HX	16	#include <linux/skbuff.h>
406ef77c HX	17	#include <linux/spinlock.h>
406ef77c HX	18	#include <net/dst.h>
	19	#include <net/xfrm.h>
	20
83815dea HX	21	static int xfrm_state_check_space(struct xfrm_state x, struct sk_buff skb)
83815dea HX	22	{
550ade84 HX	23	struct dst_entry *dst = skb->dst;
550ade84 HX	24	int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
83815dea HX	25	- skb_headroom(skb);
	26
	27	if (nhead > 0)
	28	return pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);
	29
	30	/* Check tail too... */
	31	return 0;
	32	}
	33
	34	static int xfrm_state_check(struct xfrm_state x, struct sk_buff skb)
	35	{
	36	int err = xfrm_state_check_expire(x);
	37	if (err < 0)
	38	goto err;
	39	err = xfrm_state_check_space(x, skb);
	40	err:
	41	return err;
	42	}
	43
862b82c6	44	static int xfrm_output_one(struct sk_buff *skb)
406ef77c HX	45	{
	46	struct dst_entry *dst = skb->dst;
	47	struct xfrm_state *x = dst->xfrm;
	48	int err;
	49
	50	if (skb->ip_summed == CHECKSUM_PARTIAL) {
	51	err = skb_checksum_help(skb);
	52	if (err)
	53	goto error_nolock;
	54	}
	55
	56	do {
a2deb6d2 HX	57	err = x->outer_mode->output(x, skb);
	58	if (err)
	59	goto error;
	60
406ef77c HX	61	spin_lock_bh(&x->lock);
	62	err = xfrm_state_check(x, skb);
	63	if (err)
	64	goto error;
	65
436a0a40 HX	66	if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
436a0a40 HX	67	XFRM_SKB_CB(skb)->seq = ++x->replay.oseq;
cdf7e668 HX	68	if (xfrm_aevent_is_on())
cdf7e668 HX	69	xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
436a0a40 HX	70	}
436a0a40 HX	71
406ef77c HX	72	x->curlft.bytes += skb->len;
	73	x->curlft.packets++;
	74
406ef77c HX	75	spin_unlock_bh(&x->lock);
406ef77c HX	76
b7c6538c HX	77	err = x->type->output(x, skb);
	78	if (err)
	79	goto error_nolock;
	80
406ef77c HX	81	if (!(skb->dst = dst_pop(dst))) {
	82	err = -EHOSTUNREACH;
	83	goto error_nolock;
	84	}
	85	dst = skb->dst;
	86	x = dst->xfrm;
13996378	87	} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
406ef77c HX	88
	89	err = 0;
	90
862b82c6	91	out_exit:
406ef77c HX	92	return err;
	93	error:
	94	spin_unlock_bh(&x->lock);
862b82c6 HX	95	error_nolock:
	96	kfree_skb(skb);
	97	goto out_exit;
	98	}
	99
	100	static int xfrm_output2(struct sk_buff *skb)
	101	{
	102	int err;
	103
	104	while (likely((err = xfrm_output_one(skb)) == 0)) {
	105	struct xfrm_state *x;
	106
	107	nf_reset(skb);
	108
	109	err = skb->dst->ops->local_out(skb);
	110	if (unlikely(err != 1))
	111	break;
	112
	113	x = skb->dst->xfrm;
	114	if (!x)
	115	return dst_output(skb);
	116
	117	err = nf_hook(x->inner_mode->afinfo->family,
	118	x->inner_mode->afinfo->nf_post_routing, skb,
	119	NULL, skb->dst->dev, xfrm_output2);
	120	if (unlikely(err != 1))
	121	break;
	122	}
	123
	124	return err;
	125	}
	126
	127	int xfrm_output(struct sk_buff *skb)
	128	{
	129	struct sk_buff *segs;
	130
	131	if (!skb_is_gso(skb))
	132	return xfrm_output2(skb);
	133
	134	segs = skb_gso_segment(skb, 0);
	135	kfree_skb(skb);
	136	if (unlikely(IS_ERR(segs)))
	137	return PTR_ERR(segs);
	138
	139	do {
	140	struct sk_buff *nskb = segs->next;
	141	int err;
	142
	143	segs->next = NULL;
	144	err = xfrm_output2(segs);
	145
	146	if (unlikely(err)) {
	147	while ((segs = nskb)) {
	148	nskb = segs->next;
	149	segs->next = NULL;
	150	kfree_skb(segs);
	151	}
	152	return err;
	153	}
	154
	155	segs = nskb;
	156	} while (segs);
	157
	158	return 0;
406ef77c HX	159	}
406ef77c HX	160	EXPORT_SYMBOL_GPL(xfrm_output);