184 lines
3.4 KiB
C
184 lines
3.4 KiB
C
/*
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* xfrm_output.c - Common IPsec encapsulation code.
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*
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* Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/errno.h>
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#include <linux/module.h>
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#include <linux/netdevice.h>
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#include <linux/netfilter.h>
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#include <linux/skbuff.h>
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#include <linux/spinlock.h>
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#include <net/dst.h>
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#include <net/xfrm.h>
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static int xfrm_output2(struct sk_buff *skb);
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static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct dst_entry *dst = skb->dst;
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int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
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- skb_headroom(skb);
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if (nhead > 0)
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return pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);
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/* Check tail too... */
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return 0;
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}
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static int xfrm_state_check(struct xfrm_state *x, struct sk_buff *skb)
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{
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int err = xfrm_state_check_expire(x);
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if (err < 0)
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goto err;
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err = xfrm_state_check_space(x, skb);
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err:
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return err;
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}
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static int xfrm_output_one(struct sk_buff *skb, int err)
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{
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struct dst_entry *dst = skb->dst;
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struct xfrm_state *x = dst->xfrm;
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if (err <= 0)
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goto resume;
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do {
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err = x->outer_mode->output(x, skb);
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if (err)
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goto error;
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spin_lock_bh(&x->lock);
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err = xfrm_state_check(x, skb);
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if (err)
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goto error;
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if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
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XFRM_SKB_CB(skb)->seq = ++x->replay.oseq;
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if (xfrm_aevent_is_on())
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xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
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}
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x->curlft.bytes += skb->len;
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x->curlft.packets++;
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spin_unlock_bh(&x->lock);
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err = x->type->output(x, skb);
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resume:
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if (err)
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goto error_nolock;
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if (!(skb->dst = dst_pop(dst))) {
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err = -EHOSTUNREACH;
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goto error_nolock;
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}
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dst = skb->dst;
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x = dst->xfrm;
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} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
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err = 0;
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out_exit:
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return err;
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error:
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spin_unlock_bh(&x->lock);
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error_nolock:
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kfree_skb(skb);
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goto out_exit;
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}
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int xfrm_output_resume(struct sk_buff *skb, int err)
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{
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while (likely((err = xfrm_output_one(skb, err)) == 0)) {
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struct xfrm_state *x;
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nf_reset(skb);
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err = skb->dst->ops->local_out(skb);
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if (unlikely(err != 1))
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goto out;
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x = skb->dst->xfrm;
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if (!x)
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return dst_output(skb);
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err = nf_hook(x->inner_mode->afinfo->family,
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NF_INET_POST_ROUTING, skb,
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NULL, skb->dst->dev, xfrm_output2);
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if (unlikely(err != 1))
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goto out;
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}
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if (err == -EINPROGRESS)
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err = 0;
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out:
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return err;
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}
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EXPORT_SYMBOL_GPL(xfrm_output_resume);
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static int xfrm_output2(struct sk_buff *skb)
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{
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return xfrm_output_resume(skb, 1);
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}
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static int xfrm_output_gso(struct sk_buff *skb)
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{
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struct sk_buff *segs;
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segs = skb_gso_segment(skb, 0);
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kfree_skb(skb);
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if (unlikely(IS_ERR(segs)))
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return PTR_ERR(segs);
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do {
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struct sk_buff *nskb = segs->next;
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int err;
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segs->next = NULL;
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err = xfrm_output2(segs);
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if (unlikely(err)) {
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while ((segs = nskb)) {
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nskb = segs->next;
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segs->next = NULL;
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kfree_skb(segs);
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}
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return err;
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}
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segs = nskb;
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} while (segs);
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return 0;
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}
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int xfrm_output(struct sk_buff *skb)
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{
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int err;
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if (skb_is_gso(skb))
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return xfrm_output_gso(skb);
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if (skb->ip_summed == CHECKSUM_PARTIAL) {
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err = skb_checksum_help(skb);
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if (err) {
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kfree_skb(skb);
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return err;
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}
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}
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return xfrm_output2(skb);
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}
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EXPORT_SYMBOL_GPL(xfrm_output);
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