2 * xfrm_output.c - Common IPsec encapsulation code.
4 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
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.
12 #include <linux/errno.h>
13 #include <linux/module.h>
14 #include <linux/netdevice.h>
15 #include <linux/netfilter.h>
16 #include <linux/skbuff.h>
17 #include <linux/spinlock.h>
21 static int xfrm_output2(struct sk_buff *skb);
23 static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb)
25 struct dst_entry *dst = skb->dst;
26 int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
30 return pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);
32 /* Check tail too... */
36 static int xfrm_output_one(struct sk_buff *skb, int err)
38 struct dst_entry *dst = skb->dst;
39 struct xfrm_state *x = dst->xfrm;
45 err = xfrm_state_check_space(x, skb);
49 err = x->outer_mode->output(x, skb);
53 spin_lock_bh(&x->lock);
54 err = xfrm_state_check_expire(x);
58 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
59 XFRM_SKB_CB(skb)->seq = ++x->replay.oseq;
60 if (unlikely(x->replay.oseq == 0))
61 xfrm_audit_state_replay_overflow(x, skb);
62 if (xfrm_aevent_is_on())
63 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
66 x->curlft.bytes += skb->len;
69 spin_unlock_bh(&x->lock);
71 err = x->type->output(x, skb);
75 XFRM_INC_STATS(LINUX_MIB_XFRMOUTSTATEPROTOERROR);
79 if (!(skb->dst = dst_pop(dst))) {
80 XFRM_INC_STATS(LINUX_MIB_XFRMOUTERROR);
86 } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
93 spin_unlock_bh(&x->lock);
99 int xfrm_output_resume(struct sk_buff *skb, int err)
101 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
102 struct xfrm_state *x;
106 err = skb->dst->ops->local_out(skb);
107 if (unlikely(err != 1))
112 return dst_output(skb);
114 err = nf_hook(x->inner_mode->afinfo->family,
115 NF_INET_POST_ROUTING, skb,
116 NULL, skb->dst->dev, xfrm_output2);
117 if (unlikely(err != 1))
121 if (err == -EINPROGRESS)
127 EXPORT_SYMBOL_GPL(xfrm_output_resume);
129 static int xfrm_output2(struct sk_buff *skb)
131 return xfrm_output_resume(skb, 1);
134 static int xfrm_output_gso(struct sk_buff *skb)
136 struct sk_buff *segs;
138 segs = skb_gso_segment(skb, 0);
140 if (unlikely(IS_ERR(segs)))
141 return PTR_ERR(segs);
144 struct sk_buff *nskb = segs->next;
148 err = xfrm_output2(segs);
151 while ((segs = nskb)) {
165 int xfrm_output(struct sk_buff *skb)
170 return xfrm_output_gso(skb);
172 if (skb->ip_summed == CHECKSUM_PARTIAL) {
173 err = skb_checksum_help(skb);
175 XFRM_INC_STATS(LINUX_MIB_XFRMOUTERROR);
181 return xfrm_output2(skb);
183 EXPORT_SYMBOL_GPL(xfrm_output);