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 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 while (likely((err
= xfrm_output_one(skb
, err
)) == 0)) {
137 err
= skb_dst(skb
)->ops
->local_out(skb
);
138 if (unlikely(err
!= 1))
141 if (!skb_dst(skb
)->xfrm
)
142 return dst_output(skb
);
144 err
= nf_hook(skb_dst(skb
)->ops
->family
,
145 NF_INET_POST_ROUTING
, skb
->sk
, skb
,
146 NULL
, skb_dst(skb
)->dev
, xfrm_output2
);
147 if (unlikely(err
!= 1))
151 if (err
== -EINPROGRESS
)
157 EXPORT_SYMBOL_GPL(xfrm_output_resume
);
159 static int xfrm_output2(struct sock
*sk
, struct sk_buff
*skb
)
161 return xfrm_output_resume(skb
, 1);
164 static int xfrm_output_gso(struct sock
*sk
, struct sk_buff
*skb
)
166 struct sk_buff
*segs
;
168 segs
= skb_gso_segment(skb
, 0);
171 return PTR_ERR(segs
);
176 struct sk_buff
*nskb
= segs
->next
;
180 err
= xfrm_output2(sk
, segs
);
183 kfree_skb_list(nskb
);
193 int xfrm_output(struct sock
*sk
, struct sk_buff
*skb
)
195 struct net
*net
= dev_net(skb_dst(skb
)->dev
);
199 return xfrm_output_gso(sk
, skb
);
201 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
202 err
= skb_checksum_help(skb
);
204 XFRM_INC_STATS(net
, LINUX_MIB_XFRMOUTERROR
);
210 return xfrm_output2(sk
, skb
);
212 EXPORT_SYMBOL_GPL(xfrm_output
);
214 int xfrm_inner_extract_output(struct xfrm_state
*x
, struct sk_buff
*skb
)
216 struct xfrm_mode
*inner_mode
;
217 if (x
->sel
.family
== AF_UNSPEC
)
218 inner_mode
= xfrm_ip2inner_mode(x
,
219 xfrm_af2proto(skb_dst(skb
)->ops
->family
));
221 inner_mode
= x
->inner_mode
;
223 if (inner_mode
== NULL
)
224 return -EAFNOSUPPORT
;
225 return inner_mode
->afinfo
->extract_output(x
, skb
);
227 EXPORT_SYMBOL_GPL(xfrm_inner_extract_output
);
229 void xfrm_local_error(struct sk_buff
*skb
, int mtu
)
232 struct xfrm_state_afinfo
*afinfo
;
234 if (skb
->protocol
== htons(ETH_P_IP
))
236 else if (skb
->protocol
== htons(ETH_P_IPV6
))
241 afinfo
= xfrm_state_get_afinfo(proto
);
245 afinfo
->local_error(skb
, mtu
);
246 xfrm_state_put_afinfo(afinfo
);
248 EXPORT_SYMBOL_GPL(xfrm_local_error
);