linux/net/xfrm/xfrm_output.c
Herbert Xu a2deb6d26f [IPSEC]: Move x->outer_mode->output out of locked section
RO mode is the only one that requires a locked output function.  So
it's easier to move the lock into that function rather than requiring
everyone else to run under the lock.

In particular, this allows us to move the size check into the output
function without causing a potential dead-lock should the ICMP error
somehow hit the same SA on transmission.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 14:53:44 -08:00

97 lines
2.0 KiB
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/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;
}
int xfrm_output(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;
error_nolock:
return err;
error:
spin_unlock_bh(&x->lock);
goto error_nolock;
}
EXPORT_SYMBOL_GPL(xfrm_output);