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 net *net, struct sock *sk, struct sk_buff *skb);
24 static int xfrm_skb_check_space(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 /* Children define the path of the packet through the
42 * Linux networking. Thus, destinations are stackable.
45 static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
47 struct dst_entry *child = dst_clone(skb_dst(skb)->child);
53 static int xfrm_output_one(struct sk_buff *skb, int err)
55 struct dst_entry *dst = skb_dst(skb);
56 struct xfrm_state *x = dst->xfrm;
57 struct net *net = xs_net(x);
63 err = xfrm_skb_check_space(skb);
65 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
69 err = x->outer_mode->output(x, skb);
71 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
75 spin_lock_bh(&x->lock);
77 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
78 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
83 err = xfrm_state_check_expire(x);
85 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
89 err = x->repl->overflow(x, skb);
91 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
95 x->curlft.bytes += skb->len;
98 spin_unlock_bh(&x->lock);
102 err = x->type->output(x, skb);
103 if (err == -EINPROGRESS)
108 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
112 dst = skb_dst_pop(skb);
114 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
118 skb_dst_set(skb, dst);
120 } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
125 spin_unlock_bh(&x->lock);
132 int xfrm_output_resume(struct sk_buff *skb, int err)
134 struct net *net = xs_net(skb_dst(skb)->xfrm);
136 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
139 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
140 if (unlikely(err != 1))
143 if (!skb_dst(skb)->xfrm)
144 return dst_output(net, skb->sk, skb);
146 err = nf_hook(skb_dst(skb)->ops->family,
147 NF_INET_POST_ROUTING, net, skb->sk, skb,
148 NULL, skb_dst(skb)->dev, xfrm_output2);
149 if (unlikely(err != 1))
153 if (err == -EINPROGRESS)
159 EXPORT_SYMBOL_GPL(xfrm_output_resume);
161 static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
163 return xfrm_output_resume(skb, 1);
166 static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
168 struct sk_buff *segs;
170 segs = skb_gso_segment(skb, 0);
173 return PTR_ERR(segs);
178 struct sk_buff *nskb = segs->next;
182 err = xfrm_output2(net, sk, segs);
185 kfree_skb_list(nskb);
195 int xfrm_output(struct sock *sk, struct sk_buff *skb)
197 struct net *net = dev_net(skb_dst(skb)->dev);
201 return xfrm_output_gso(net, sk, skb);
203 if (skb->ip_summed == CHECKSUM_PARTIAL) {
204 err = skb_checksum_help(skb);
206 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
212 return xfrm_output2(net, sk, skb);
214 EXPORT_SYMBOL_GPL(xfrm_output);
216 int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
218 struct xfrm_mode *inner_mode;
219 if (x->sel.family == AF_UNSPEC)
220 inner_mode = xfrm_ip2inner_mode(x,
221 xfrm_af2proto(skb_dst(skb)->ops->family));
223 inner_mode = x->inner_mode;
225 if (inner_mode == NULL)
226 return -EAFNOSUPPORT;
227 return inner_mode->afinfo->extract_output(x, skb);
229 EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
231 void xfrm_local_error(struct sk_buff *skb, int mtu)
234 struct xfrm_state_afinfo *afinfo;
236 if (skb->protocol == htons(ETH_P_IP))
238 else if (skb->protocol == htons(ETH_P_IPV6))
243 afinfo = xfrm_state_get_afinfo(proto);
247 afinfo->local_error(skb, mtu);
248 xfrm_state_put_afinfo(afinfo);
250 EXPORT_SYMBOL_GPL(xfrm_local_error);