blob: cc3676eb6239707909e41c34841abbd4ea8958dd [file] [log] [blame]
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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090017#include <linux/slab.h>
Herbert Xu406ef772007-10-08 17:16:30 -070018#include <linux/spinlock.h>
Herbert Xu406ef772007-10-08 17:16:30 -070019#include <net/dst.h>
20#include <net/xfrm.h>
21
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -050022static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb);
Herbert Xuc6581a42007-11-13 21:43:43 -080023
Steffen Klassert26b20722012-03-21 23:32:39 +000024static int xfrm_skb_check_space(struct sk_buff *skb)
Herbert Xu83815de2007-10-08 17:25:08 -070025{
Eric Dumazetadf30902009-06-02 05:19:30 +000026 struct dst_entry *dst = skb_dst(skb);
Herbert Xu550ade82007-11-13 21:33:01 -080027 int nhead = dst->header_len + LL_RESERVED_SPACE(dst->dev)
Herbert Xu83815de2007-10-08 17:25:08 -070028 - skb_headroom(skb);
Johannes Bergf5184d22008-05-12 20:48:31 -070029 int ntail = dst->dev->needed_tailroom - skb_tailroom(skb);
Herbert Xu83815de2007-10-08 17:25:08 -070030
Herbert Xud01dbeb2008-09-30 02:03:19 -070031 if (nhead <= 0) {
32 if (ntail <= 0)
33 return 0;
34 nhead = 0;
35 } else if (ntail < 0)
36 ntail = 0;
Herbert Xu83815de2007-10-08 17:25:08 -070037
Herbert Xud01dbeb2008-09-30 02:03:19 -070038 return pskb_expand_head(skb, nhead, ntail, GFP_ATOMIC);
Herbert Xu83815de2007-10-08 17:25:08 -070039}
40
Ying Xue9449c3c2015-05-12 18:29:44 +080041/* Children define the path of the packet through the
42 * Linux networking. Thus, destinations are stackable.
43 */
44
45static struct dst_entry *skb_dst_pop(struct sk_buff *skb)
46{
47 struct dst_entry *child = dst_clone(skb_dst(skb)->child);
48
49 skb_dst_drop(skb);
50 return child;
51}
52
Herbert Xuc6581a42007-11-13 21:43:43 -080053static int xfrm_output_one(struct sk_buff *skb, int err)
Herbert Xu406ef772007-10-08 17:16:30 -070054{
Eric Dumazetadf30902009-06-02 05:19:30 +000055 struct dst_entry *dst = skb_dst(skb);
Herbert Xu406ef772007-10-08 17:16:30 -070056 struct xfrm_state *x = dst->xfrm;
Alexey Dobriyana6483b72008-11-25 17:38:20 -080057 struct net *net = xs_net(x);
Herbert Xu406ef772007-10-08 17:16:30 -070058
Herbert Xuc6581a42007-11-13 21:43:43 -080059 if (err <= 0)
60 goto resume;
Herbert Xu406ef772007-10-08 17:16:30 -070061
62 do {
Steffen Klassert26b20722012-03-21 23:32:39 +000063 err = xfrm_skb_check_space(skb);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080064 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080065 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xu910ef702007-12-18 22:14:25 -080066 goto error_nolock;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080067 }
Herbert Xu910ef702007-12-18 22:14:25 -080068
Herbert Xua2deb6d22007-11-13 21:39:38 -080069 err = x->outer_mode->output(x, skb);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080070 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080071 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
Herbert Xu910ef702007-12-18 22:14:25 -080072 goto error_nolock;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080073 }
Herbert Xua2deb6d22007-11-13 21:39:38 -080074
Herbert Xu406ef772007-10-08 17:16:30 -070075 spin_lock_bh(&x->lock);
Li RongQingbb65a9c2012-12-28 16:06:28 +080076
77 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
78 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
Timo Teräs497574c2013-05-22 01:40:47 +000079 err = -EINVAL;
Li RongQingfa8599d2013-02-01 13:17:16 +080080 goto error;
Li RongQingbb65a9c2012-12-28 16:06:28 +080081 }
82
Herbert Xu910ef702007-12-18 22:14:25 -080083 err = xfrm_state_check_expire(x);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080084 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080085 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
Herbert Xu406ef772007-10-08 17:16:30 -070086 goto error;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080087 }
Herbert Xu406ef772007-10-08 17:16:30 -070088
Steffen Klassert9fdc4882011-03-08 00:08:32 +000089 err = x->repl->overflow(x, skb);
90 if (err) {
91 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
92 goto error;
Herbert Xu436a0a42007-10-08 17:25:53 -070093 }
94
Herbert Xu406ef772007-10-08 17:16:30 -070095 x->curlft.bytes += skb->len;
96 x->curlft.packets++;
97
Herbert Xu406ef772007-10-08 17:16:30 -070098 spin_unlock_bh(&x->lock);
99
Steffen Klassert3bc07322011-03-15 21:08:28 +0000100 skb_dst_force(skb);
101
Herbert Xub7c65382007-10-09 13:33:35 -0700102 err = x->type->output(x, skb);
Herbert Xufcb8c152007-12-30 21:09:38 -0800103 if (err == -EINPROGRESS)
Jean Sacrenebd46872013-06-01 16:23:15 +0000104 goto out;
Herbert Xuc6581a42007-11-13 21:43:43 -0800105
106resume:
Masahide NAKAMURA0aa64772007-12-20 20:43:36 -0800107 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -0800108 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
Herbert Xub7c65382007-10-09 13:33:35 -0700109 goto error_nolock;
Masahide NAKAMURA0aa64772007-12-20 20:43:36 -0800110 }
Herbert Xub7c65382007-10-09 13:33:35 -0700111
Steffen Klassert8764ab22010-06-04 01:57:38 +0000112 dst = skb_dst_pop(skb);
Eric Dumazetadf30902009-06-02 05:19:30 +0000113 if (!dst) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -0800114 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xu406ef772007-10-08 17:16:30 -0700115 err = -EHOSTUNREACH;
116 goto error_nolock;
117 }
Steffen Klasserte4334302011-03-15 21:09:32 +0000118 skb_dst_set(skb, dst);
Herbert Xu406ef772007-10-08 17:16:30 -0700119 x = dst->xfrm;
Herbert Xu13996372007-10-17 21:35:51 -0700120 } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
Herbert Xu406ef772007-10-08 17:16:30 -0700121
Jean Sacrenebd46872013-06-01 16:23:15 +0000122 return 0;
Herbert Xu406ef772007-10-08 17:16:30 -0700123
Herbert Xu406ef772007-10-08 17:16:30 -0700124error:
125 spin_unlock_bh(&x->lock);
Herbert Xu862b82c2007-11-13 21:43:11 -0800126error_nolock:
127 kfree_skb(skb);
Jean Sacrenebd46872013-06-01 16:23:15 +0000128out:
129 return err;
Herbert Xu862b82c2007-11-13 21:43:11 -0800130}
131
Herbert Xuc6581a42007-11-13 21:43:43 -0800132int xfrm_output_resume(struct sk_buff *skb, int err)
Herbert Xu862b82c2007-11-13 21:43:11 -0800133{
Eric W. Biederman29a26a52015-09-15 20:04:16 -0500134 struct net *net = xs_net(skb_dst(skb)->xfrm);
Eric W. Biedermanbe10de02015-09-17 17:21:31 -0500135
Herbert Xuc6581a42007-11-13 21:43:43 -0800136 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
Herbert Xu862b82c2007-11-13 21:43:11 -0800137 nf_reset(skb);
138
Eric W. Biedermancf91a992015-10-07 16:48:45 -0500139 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
Herbert Xu862b82c2007-11-13 21:43:11 -0800140 if (unlikely(err != 1))
Herbert Xuc6581a42007-11-13 21:43:43 -0800141 goto out;
Herbert Xu862b82c2007-11-13 21:43:11 -0800142
Eric Dumazetadf30902009-06-02 05:19:30 +0000143 if (!skb_dst(skb)->xfrm)
Eric W. Biederman13206b62015-10-07 16:48:35 -0500144 return dst_output(net, skb->sk, skb);
Herbert Xu862b82c2007-11-13 21:43:11 -0800145
Eric Dumazetadf30902009-06-02 05:19:30 +0000146 err = nf_hook(skb_dst(skb)->ops->family,
Eric W. Biederman29a26a52015-09-15 20:04:16 -0500147 NF_INET_POST_ROUTING, net, skb->sk, skb,
Eric Dumazetadf30902009-06-02 05:19:30 +0000148 NULL, skb_dst(skb)->dev, xfrm_output2);
Herbert Xu862b82c2007-11-13 21:43:11 -0800149 if (unlikely(err != 1))
Herbert Xuc6581a42007-11-13 21:43:43 -0800150 goto out;
Herbert Xu862b82c2007-11-13 21:43:11 -0800151 }
152
Herbert Xuc6581a42007-11-13 21:43:43 -0800153 if (err == -EINPROGRESS)
154 err = 0;
155
156out:
Herbert Xu862b82c2007-11-13 21:43:11 -0800157 return err;
158}
Herbert Xuc6581a42007-11-13 21:43:43 -0800159EXPORT_SYMBOL_GPL(xfrm_output_resume);
Herbert Xu862b82c2007-11-13 21:43:11 -0800160
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500161static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
Herbert Xuc6581a42007-11-13 21:43:43 -0800162{
163 return xfrm_output_resume(skb, 1);
164}
165
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500166static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
Herbert Xu862b82c2007-11-13 21:43:11 -0800167{
168 struct sk_buff *segs;
169
Herbert Xu862b82c2007-11-13 21:43:11 -0800170 segs = skb_gso_segment(skb, 0);
171 kfree_skb(skb);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700172 if (IS_ERR(segs))
Herbert Xu862b82c2007-11-13 21:43:11 -0800173 return PTR_ERR(segs);
Florian Westphal330966e2014-10-20 13:49:17 +0200174 if (segs == NULL)
175 return -EINVAL;
Herbert Xu862b82c2007-11-13 21:43:11 -0800176
177 do {
178 struct sk_buff *nskb = segs->next;
179 int err;
180
181 segs->next = NULL;
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500182 err = xfrm_output2(net, sk, segs);
Herbert Xu862b82c2007-11-13 21:43:11 -0800183
184 if (unlikely(err)) {
Florian Westphal46cfd722014-09-10 01:08:46 +0200185 kfree_skb_list(nskb);
Herbert Xu862b82c2007-11-13 21:43:11 -0800186 return err;
187 }
188
189 segs = nskb;
190 } while (segs);
191
192 return 0;
Herbert Xu406ef772007-10-08 17:16:30 -0700193}
Herbert Xuc6581a42007-11-13 21:43:43 -0800194
David Miller7026b1d2015-04-05 22:19:04 -0400195int xfrm_output(struct sock *sk, struct sk_buff *skb)
Herbert Xuc6581a42007-11-13 21:43:43 -0800196{
Eric Dumazetadf30902009-06-02 05:19:30 +0000197 struct net *net = dev_net(skb_dst(skb)->dev);
Herbert Xuc6581a42007-11-13 21:43:43 -0800198 int err;
199
200 if (skb_is_gso(skb))
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500201 return xfrm_output_gso(net, sk, skb);
Herbert Xuc6581a42007-11-13 21:43:43 -0800202
203 if (skb->ip_summed == CHECKSUM_PARTIAL) {
204 err = skb_checksum_help(skb);
205 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -0800206 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xuc6581a42007-11-13 21:43:43 -0800207 kfree_skb(skb);
208 return err;
209 }
210 }
211
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500212 return xfrm_output2(net, sk, skb);
Herbert Xuc6581a42007-11-13 21:43:43 -0800213}
Fabian Frederickfc680862014-05-12 19:54:34 +0200214EXPORT_SYMBOL_GPL(xfrm_output);
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700215
216int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
217{
218 struct xfrm_mode *inner_mode;
219 if (x->sel.family == AF_UNSPEC)
220 inner_mode = xfrm_ip2inner_mode(x,
Eric Dumazetadf30902009-06-02 05:19:30 +0000221 xfrm_af2proto(skb_dst(skb)->ops->family));
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700222 else
223 inner_mode = x->inner_mode;
224
225 if (inner_mode == NULL)
226 return -EAFNOSUPPORT;
227 return inner_mode->afinfo->extract_output(x, skb);
228}
Fabian Frederickfc680862014-05-12 19:54:34 +0200229EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700230
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200231void xfrm_local_error(struct sk_buff *skb, int mtu)
232{
Hannes Frederic Sowa844d4872013-08-18 13:47:01 +0200233 unsigned int proto;
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200234 struct xfrm_state_afinfo *afinfo;
235
Hannes Frederic Sowa844d4872013-08-18 13:47:01 +0200236 if (skb->protocol == htons(ETH_P_IP))
237 proto = AF_INET;
238 else if (skb->protocol == htons(ETH_P_IPV6))
239 proto = AF_INET6;
240 else
241 return;
242
243 afinfo = xfrm_state_get_afinfo(proto);
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200244 if (!afinfo)
245 return;
246
247 afinfo->local_error(skb, mtu);
248 xfrm_state_put_afinfo(afinfo);
249}
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200250EXPORT_SYMBOL_GPL(xfrm_local_error);