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/slab.h>
18 #include <linux/spinlock.h>
22 static int xfrm_output2(struct sk_buff *skb);
24 static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb)
26 struct dst_entry *dst = skb_dst(skb);
27 int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
29 int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
38 return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
41 static int xfrm_output_one(struct sk_buff *skb, int err)
43 struct dst_entry *dst = skb_dst(skb);
44 struct xfrm_state *x = dst->xfrm;
45 struct net *net = xs_net(x);
51 err = xfrm_state_check_space(x, skb);
53 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
57 err = x->outer_mode->output(x, skb);
59 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
63 spin_lock_bh(&x->lock);
64 err = xfrm_state_check_expire(x);
66 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
70 err = x->repl->overflow(x, skb);
72 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
76 x->curlft.bytes += skb->len;
79 spin_unlock_bh(&x->lock);
81 err = x->type->output(x, skb);
82 if (err == -EINPROGRESS)
87 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
91 dst = skb_dst_pop(skb);
93 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
97 skb_dst_set(skb, dst_clone(dst));
99 } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
106 spin_unlock_bh(&x->lock);
112 int xfrm_output_resume(struct sk_buff *skb, int err)
114 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
117 err = skb_dst(skb)->ops->local_out(skb);
118 if (unlikely(err != 1))
121 if (!skb_dst(skb)->xfrm)
122 return dst_output(skb);
124 err = nf_hook(skb_dst(skb)->ops->family,
125 NF_INET_POST_ROUTING, skb,
126 NULL, skb_dst(skb)->dev, xfrm_output2);
127 if (unlikely(err != 1))
131 if (err == -EINPROGRESS)
137 EXPORT_SYMBOL_GPL(xfrm_output_resume);
139 static int xfrm_output2(struct sk_buff *skb)
141 return xfrm_output_resume(skb, 1);
144 static int xfrm_output_gso(struct sk_buff *skb)
146 struct sk_buff *segs;
148 segs = skb_gso_segment(skb, 0);
151 return PTR_ERR(segs);
154 struct sk_buff *nskb = segs->next;
158 err = xfrm_output2(segs);
161 while ((segs = nskb)) {
175 int xfrm_output(struct sk_buff *skb)
177 struct net *net = dev_net(skb_dst(skb)->dev);
181 return xfrm_output_gso(skb);
183 if (skb->ip_summed == CHECKSUM_PARTIAL) {
184 err = skb_checksum_help(skb);
186 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
192 return xfrm_output2(skb);
195 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
197 struct xfrm_mode *inner_mode;
198 if (x->sel.family == AF_UNSPEC)
199 inner_mode = xfrm_ip2inner_mode(x,
200 xfrm_af2proto(skb_dst(skb)->ops->family));
202 inner_mode = x->inner_mode;
204 if (inner_mode == NULL)
205 return -EAFNOSUPPORT;
206 return inner_mode->afinfo->extract_output(x, skb);
209 EXPORT_SYMBOL_GPL(xfrm_output);
210 EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);