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Herbert Xu406ef772007-10-08 17:16:30 -07001/*
2 * xfrm_output.c - Common IPsec encapsulation code.
3 *
4 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
5 *
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.
10 */
11
12#include <linux/errno.h>
13#include <linux/module.h>
14#include <linux/netdevice.h>
Herbert Xu862b82c2007-11-13 21:43:11 -080015#include <linux/netfilter.h>
Herbert Xu406ef772007-10-08 17:16:30 -070016#include <linux/skbuff.h>
17#include <linux/spinlock.h>
Herbert Xu406ef772007-10-08 17:16:30 -070018#include <net/dst.h>
19#include <net/xfrm.h>
20
Herbert Xuc6581a42007-11-13 21:43:43 -080021static int xfrm_output2(struct sk_buff *skb);
22
Herbert Xu83815de2007-10-08 17:25:08 -070023static int xfrm_state_check_space(struct xfrm_state *x, struct sk_buff *skb)
24{
Eric Dumazetadf30902009-06-02 05:19:30 +000025 struct dst_entry *dst = skb_dst(skb);
Herbert Xu550ade82007-11-13 21:33:01 -080026 int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
Herbert Xu83815de2007-10-08 17:25:08 -070027 - skb_headroom(skb);
Johannes Bergf5184d22008-05-12 20:48:31 -070028 int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
Herbert Xu83815de2007-10-08 17:25:08 -070029
Herbert Xud01dbeb2008-09-30 02:03:19 -070030 if (nhead <= 0) {
31 if (ntail <= 0)
32 return 0;
33 nhead = 0;
34 } else if (ntail < 0)
35 ntail = 0;
Herbert Xu83815de2007-10-08 17:25:08 -070036
Herbert Xud01dbeb2008-09-30 02:03:19 -070037 return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
Herbert Xu83815de2007-10-08 17:25:08 -070038}
39
Herbert Xuc6581a42007-11-13 21:43:43 -080040static int xfrm_output_one(struct sk_buff *skb, int err)
Herbert Xu406ef772007-10-08 17:16:30 -070041{
Eric Dumazetadf30902009-06-02 05:19:30 +000042 struct dst_entry *dst = skb_dst(skb);
Herbert Xu406ef772007-10-08 17:16:30 -070043 struct xfrm_state *x = dst->xfrm;
Alexey Dobriyana6483b72008-11-25 17:38:20 -080044 struct net *net = xs_net(x);
Herbert Xu406ef772007-10-08 17:16:30 -070045
Herbert Xuc6581a42007-11-13 21:43:43 -080046 if (err <= 0)
47 goto resume;
Herbert Xu406ef772007-10-08 17:16:30 -070048
49 do {
Herbert Xu910ef702007-12-18 22:14:25 -080050 err = xfrm_state_check_space(x, skb);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080051 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080052 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xu910ef702007-12-18 22:14:25 -080053 goto error_nolock;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080054 }
Herbert Xu910ef702007-12-18 22:14:25 -080055
Herbert Xua2deb6d2007-11-13 21:39:38 -080056 err = x->outer_mode->output(x, skb);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080057 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080058 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
Herbert Xu910ef702007-12-18 22:14:25 -080059 goto error_nolock;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080060 }
Herbert Xua2deb6d2007-11-13 21:39:38 -080061
Herbert Xu406ef772007-10-08 17:16:30 -070062 spin_lock_bh(&x->lock);
Herbert Xu910ef702007-12-18 22:14:25 -080063 err = xfrm_state_check_expire(x);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080064 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080065 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
Herbert Xu406ef772007-10-08 17:16:30 -070066 goto error;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080067 }
Herbert Xu406ef772007-10-08 17:16:30 -070068
Herbert Xu436a0a42007-10-08 17:25:53 -070069 if (x->type->flags & XFRM_TYPE_REPLAY_PROT) {
Herbert Xub318e0e2008-02-12 22:50:35 -080070 XFRM_SKB_CB(skb)->seq.output = ++x->replay.oseq;
Paul Mooree1af9f22007-12-21 14:59:08 -080071 if (unlikely(x->replay.oseq == 0)) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080072 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
Paul Mooree1af9f22007-12-21 14:59:08 -080073 x->replay.oseq--;
Paul Mooreafeb14b2007-12-21 14:58:11 -080074 xfrm_audit_state_replay_overflow(x, skb);
Herbert Xudbb1db82008-01-01 23:52:59 -080075 err = -EOVERFLOW;
Paul Mooree1af9f22007-12-21 14:59:08 -080076 goto error;
77 }
Alexey Dobriyana6483b72008-11-25 17:38:20 -080078 if (xfrm_aevent_is_on(net))
Herbert Xucdf7e662007-10-08 17:26:34 -070079 xfrm_replay_notify(x, XFRM_REPLAY_UPDATE);
Herbert Xu436a0a42007-10-08 17:25:53 -070080 }
81
Herbert Xu406ef772007-10-08 17:16:30 -070082 x->curlft.bytes += skb->len;
83 x->curlft.packets++;
84
Herbert Xu406ef772007-10-08 17:16:30 -070085 spin_unlock_bh(&x->lock);
86
Herbert Xub7c65382007-10-09 13:33:35 -070087 err = x->type->output(x, skb);
Herbert Xufcb8c152007-12-30 21:09:38 -080088 if (err == -EINPROGRESS)
89 goto out_exit;
Herbert Xuc6581a42007-11-13 21:43:43 -080090
91resume:
Masahide NAKAMURA0aa64772007-12-20 20:43:36 -080092 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080093 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
Herbert Xub7c65382007-10-09 13:33:35 -070094 goto error_nolock;
Masahide NAKAMURA0aa64772007-12-20 20:43:36 -080095 }
Herbert Xub7c65382007-10-09 13:33:35 -070096
Eric Dumazetadf30902009-06-02 05:19:30 +000097 dst = dst_pop(dst);
98 if (!dst) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080099 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xu406ef772007-10-08 17:16:30 -0700100 err = -EHOSTUNREACH;
101 goto error_nolock;
102 }
Eric Dumazetadf30902009-06-02 05:19:30 +0000103 skb_dst_set(skb, dst);
Herbert Xu406ef772007-10-08 17:16:30 -0700104 x = dst->xfrm;
Herbert Xu13996372007-10-17 21:35:51 -0700105 } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
Herbert Xu406ef772007-10-08 17:16:30 -0700106
107 err = 0;
108
Herbert Xu862b82c2007-11-13 21:43:11 -0800109out_exit:
Herbert Xu406ef772007-10-08 17:16:30 -0700110 return err;
111error:
112 spin_unlock_bh(&x->lock);
Herbert Xu862b82c2007-11-13 21:43:11 -0800113error_nolock:
114 kfree_skb(skb);
115 goto out_exit;
116}
117
Herbert Xuc6581a42007-11-13 21:43:43 -0800118int xfrm_output_resume(struct sk_buff *skb, int err)
Herbert Xu862b82c2007-11-13 21:43:11 -0800119{
Herbert Xuc6581a42007-11-13 21:43:43 -0800120 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
Herbert Xu862b82c2007-11-13 21:43:11 -0800121 nf_reset(skb);
122
Eric Dumazetadf30902009-06-02 05:19:30 +0000123 err = skb_dst(skb)->ops->local_out(skb);
Herbert Xu862b82c2007-11-13 21:43:11 -0800124 if (unlikely(err != 1))
Herbert Xuc6581a42007-11-13 21:43:43 -0800125 goto out;
Herbert Xu862b82c2007-11-13 21:43:11 -0800126
Eric Dumazetadf30902009-06-02 05:19:30 +0000127 if (!skb_dst(skb)->xfrm)
Herbert Xu862b82c2007-11-13 21:43:11 -0800128 return dst_output(skb);
129
Eric Dumazetadf30902009-06-02 05:19:30 +0000130 err = nf_hook(skb_dst(skb)->ops->family,
David S. Miller294b4ba2007-11-14 01:57:47 -0800131 NF_INET_POST_ROUTING, skb,
Eric Dumazetadf30902009-06-02 05:19:30 +0000132 NULL, skb_dst(skb)->dev, xfrm_output2);
Herbert Xu862b82c2007-11-13 21:43:11 -0800133 if (unlikely(err != 1))
Herbert Xuc6581a42007-11-13 21:43:43 -0800134 goto out;
Herbert Xu862b82c2007-11-13 21:43:11 -0800135 }
136
Herbert Xuc6581a42007-11-13 21:43:43 -0800137 if (err == -EINPROGRESS)
138 err = 0;
139
140out:
Herbert Xu862b82c2007-11-13 21:43:11 -0800141 return err;
142}
Herbert Xuc6581a42007-11-13 21:43:43 -0800143EXPORT_SYMBOL_GPL(xfrm_output_resume);
Herbert Xu862b82c2007-11-13 21:43:11 -0800144
Herbert Xuc6581a42007-11-13 21:43:43 -0800145static int xfrm_output2(struct sk_buff *skb)
146{
147 return xfrm_output_resume(skb, 1);
148}
149
150static int xfrm_output_gso(struct sk_buff *skb)
Herbert Xu862b82c2007-11-13 21:43:11 -0800151{
152 struct sk_buff *segs;
153
Herbert Xu862b82c2007-11-13 21:43:11 -0800154 segs = skb_gso_segment(skb, 0);
155 kfree_skb(skb);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700156 if (IS_ERR(segs))
Herbert Xu862b82c2007-11-13 21:43:11 -0800157 return PTR_ERR(segs);
158
159 do {
160 struct sk_buff *nskb = segs->next;
161 int err;
162
163 segs->next = NULL;
164 err = xfrm_output2(segs);
165
166 if (unlikely(err)) {
167 while ((segs = nskb)) {
168 nskb = segs->next;
169 segs->next = NULL;
170 kfree_skb(segs);
171 }
172 return err;
173 }
174
175 segs = nskb;
176 } while (segs);
177
178 return 0;
Herbert Xu406ef772007-10-08 17:16:30 -0700179}
Herbert Xuc6581a42007-11-13 21:43:43 -0800180
181int xfrm_output(struct sk_buff *skb)
182{
Eric Dumazetadf30902009-06-02 05:19:30 +0000183 struct net *net = dev_net(skb_dst(skb)->dev);
Herbert Xuc6581a42007-11-13 21:43:43 -0800184 int err;
185
186 if (skb_is_gso(skb))
187 return xfrm_output_gso(skb);
188
189 if (skb->ip_summed == CHECKSUM_PARTIAL) {
190 err = skb_checksum_help(skb);
191 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -0800192 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xuc6581a42007-11-13 21:43:43 -0800193 kfree_skb(skb);
194 return err;
195 }
196 }
197
198 return xfrm_output2(skb);
199}
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700200
201int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
202{
203 struct xfrm_mode *inner_mode;
204 if (x->sel.family == AF_UNSPEC)
205 inner_mode = xfrm_ip2inner_mode(x,
Eric Dumazetadf30902009-06-02 05:19:30 +0000206 xfrm_af2proto(skb_dst(skb)->ops->family));
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700207 else
208 inner_mode = x->inner_mode;
209
210 if (inner_mode == NULL)
211 return -EAFNOSUPPORT;
212 return inner_mode->afinfo->extract_output(x, skb);
213}
214
Herbert Xu406ef772007-10-08 17:16:30 -0700215EXPORT_SYMBOL_GPL(xfrm_output);
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700216EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);