blob: d864a6d9e517b572279a9ae0d44bc3245c486c9e [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
Lorenzo Colittibf25c792017-08-11 02:11:33 +090069 if (x->props.output_mark)
70 skb->mark = x->props.output_mark;
71
Herbert Xua2deb6d22007-11-13 21:39:38 -080072 err = x->outer_mode->output(x, skb);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080073 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080074 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEMODEERROR);
Herbert Xu910ef702007-12-18 22:14:25 -080075 goto error_nolock;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080076 }
Herbert Xua2deb6d22007-11-13 21:39:38 -080077
Herbert Xu406ef772007-10-08 17:16:30 -070078 spin_lock_bh(&x->lock);
Li RongQingbb65a9c2012-12-28 16:06:28 +080079
80 if (unlikely(x->km.state != XFRM_STATE_VALID)) {
81 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEINVALID);
Timo Teräs497574c2013-05-22 01:40:47 +000082 err = -EINVAL;
Li RongQingfa8599d2013-02-01 13:17:16 +080083 goto error;
Li RongQingbb65a9c2012-12-28 16:06:28 +080084 }
85
Herbert Xu910ef702007-12-18 22:14:25 -080086 err = xfrm_state_check_expire(x);
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080087 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -080088 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEEXPIRED);
Herbert Xu406ef772007-10-08 17:16:30 -070089 goto error;
Masahide NAKAMURAb15c4bc2007-12-24 16:00:09 -080090 }
Herbert Xu406ef772007-10-08 17:16:30 -070091
Steffen Klassert9fdc4882011-03-08 00:08:32 +000092 err = x->repl->overflow(x, skb);
93 if (err) {
94 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATESEQERROR);
95 goto error;
Herbert Xu436a0a42007-10-08 17:25:53 -070096 }
97
Herbert Xu406ef772007-10-08 17:16:30 -070098 x->curlft.bytes += skb->len;
99 x->curlft.packets++;
100
Herbert Xu406ef772007-10-08 17:16:30 -0700101 spin_unlock_bh(&x->lock);
102
Steffen Klassert3bc07322011-03-15 21:08:28 +0000103 skb_dst_force(skb);
104
Steffen Klassert215276c2016-02-22 10:56:45 +0100105 /* Inner headers are invalid now. */
106 skb->encapsulation = 0;
107
Herbert Xub7c65382007-10-09 13:33:35 -0700108 err = x->type->output(x, skb);
Herbert Xufcb8c152007-12-30 21:09:38 -0800109 if (err == -EINPROGRESS)
Jean Sacrenebd46872013-06-01 16:23:15 +0000110 goto out;
Herbert Xuc6581a42007-11-13 21:43:43 -0800111
112resume:
Masahide NAKAMURA0aa64772007-12-20 20:43:36 -0800113 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -0800114 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEPROTOERROR);
Herbert Xub7c65382007-10-09 13:33:35 -0700115 goto error_nolock;
Masahide NAKAMURA0aa64772007-12-20 20:43:36 -0800116 }
Herbert Xub7c65382007-10-09 13:33:35 -0700117
Steffen Klassert8764ab22010-06-04 01:57:38 +0000118 dst = skb_dst_pop(skb);
Eric Dumazetadf30902009-06-02 05:19:30 +0000119 if (!dst) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -0800120 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xu406ef772007-10-08 17:16:30 -0700121 err = -EHOSTUNREACH;
122 goto error_nolock;
123 }
Steffen Klasserte4334302011-03-15 21:09:32 +0000124 skb_dst_set(skb, dst);
Herbert Xu406ef772007-10-08 17:16:30 -0700125 x = dst->xfrm;
Herbert Xu13996372007-10-17 21:35:51 -0700126 } while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));
Herbert Xu406ef772007-10-08 17:16:30 -0700127
Jean Sacrenebd46872013-06-01 16:23:15 +0000128 return 0;
Herbert Xu406ef772007-10-08 17:16:30 -0700129
Herbert Xu406ef772007-10-08 17:16:30 -0700130error:
131 spin_unlock_bh(&x->lock);
Herbert Xu862b82c2007-11-13 21:43:11 -0800132error_nolock:
133 kfree_skb(skb);
Jean Sacrenebd46872013-06-01 16:23:15 +0000134out:
135 return err;
Herbert Xu862b82c2007-11-13 21:43:11 -0800136}
137
Herbert Xuc6581a42007-11-13 21:43:43 -0800138int xfrm_output_resume(struct sk_buff *skb, int err)
Herbert Xu862b82c2007-11-13 21:43:11 -0800139{
Eric W. Biederman29a26a52015-09-15 20:04:16 -0500140 struct net *net = xs_net(skb_dst(skb)->xfrm);
Eric W. Biedermanbe10de02015-09-17 17:21:31 -0500141
Herbert Xuc6581a42007-11-13 21:43:43 -0800142 while (likely((err = xfrm_output_one(skb, err)) == 0)) {
Herbert Xu862b82c2007-11-13 21:43:11 -0800143 nf_reset(skb);
144
Eric W. Biedermancf91a992015-10-07 16:48:45 -0500145 err = skb_dst(skb)->ops->local_out(net, skb->sk, skb);
Herbert Xu862b82c2007-11-13 21:43:11 -0800146 if (unlikely(err != 1))
Herbert Xuc6581a42007-11-13 21:43:43 -0800147 goto out;
Herbert Xu862b82c2007-11-13 21:43:11 -0800148
Eric Dumazetadf30902009-06-02 05:19:30 +0000149 if (!skb_dst(skb)->xfrm)
Eric W. Biederman13206b62015-10-07 16:48:35 -0500150 return dst_output(net, skb->sk, skb);
Herbert Xu862b82c2007-11-13 21:43:11 -0800151
Eric Dumazetadf30902009-06-02 05:19:30 +0000152 err = nf_hook(skb_dst(skb)->ops->family,
Eric W. Biederman29a26a52015-09-15 20:04:16 -0500153 NF_INET_POST_ROUTING, net, skb->sk, skb,
Eric Dumazetadf30902009-06-02 05:19:30 +0000154 NULL, skb_dst(skb)->dev, xfrm_output2);
Herbert Xu862b82c2007-11-13 21:43:11 -0800155 if (unlikely(err != 1))
Herbert Xuc6581a42007-11-13 21:43:43 -0800156 goto out;
Herbert Xu862b82c2007-11-13 21:43:11 -0800157 }
158
Herbert Xuc6581a42007-11-13 21:43:43 -0800159 if (err == -EINPROGRESS)
160 err = 0;
161
162out:
Herbert Xu862b82c2007-11-13 21:43:11 -0800163 return err;
164}
Herbert Xuc6581a42007-11-13 21:43:43 -0800165EXPORT_SYMBOL_GPL(xfrm_output_resume);
Herbert Xu862b82c2007-11-13 21:43:11 -0800166
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500167static int xfrm_output2(struct net *net, struct sock *sk, struct sk_buff *skb)
Herbert Xuc6581a42007-11-13 21:43:43 -0800168{
169 return xfrm_output_resume(skb, 1);
170}
171
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500172static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb)
Herbert Xu862b82c2007-11-13 21:43:11 -0800173{
174 struct sk_buff *segs;
175
Konstantin Khlebnikov9207f9d2016-01-08 15:21:46 +0300176 BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
177 BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET);
Herbert Xu862b82c2007-11-13 21:43:11 -0800178 segs = skb_gso_segment(skb, 0);
179 kfree_skb(skb);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700180 if (IS_ERR(segs))
Herbert Xu862b82c2007-11-13 21:43:11 -0800181 return PTR_ERR(segs);
Florian Westphal330966e2014-10-20 13:49:17 +0200182 if (segs == NULL)
183 return -EINVAL;
Herbert Xu862b82c2007-11-13 21:43:11 -0800184
185 do {
186 struct sk_buff *nskb = segs->next;
187 int err;
188
189 segs->next = NULL;
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500190 err = xfrm_output2(net, sk, segs);
Herbert Xu862b82c2007-11-13 21:43:11 -0800191
192 if (unlikely(err)) {
Florian Westphal46cfd722014-09-10 01:08:46 +0200193 kfree_skb_list(nskb);
Herbert Xu862b82c2007-11-13 21:43:11 -0800194 return err;
195 }
196
197 segs = nskb;
198 } while (segs);
199
200 return 0;
Herbert Xu406ef772007-10-08 17:16:30 -0700201}
Herbert Xuc6581a42007-11-13 21:43:43 -0800202
David Miller7026b1d2015-04-05 22:19:04 -0400203int xfrm_output(struct sock *sk, struct sk_buff *skb)
Herbert Xuc6581a42007-11-13 21:43:43 -0800204{
Eric Dumazetadf30902009-06-02 05:19:30 +0000205 struct net *net = dev_net(skb_dst(skb)->dev);
Herbert Xuc6581a42007-11-13 21:43:43 -0800206 int err;
207
208 if (skb_is_gso(skb))
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500209 return xfrm_output_gso(net, sk, skb);
Herbert Xuc6581a42007-11-13 21:43:43 -0800210
211 if (skb->ip_summed == CHECKSUM_PARTIAL) {
212 err = skb_checksum_help(skb);
213 if (err) {
Alexey Dobriyan59c99402008-11-25 17:59:52 -0800214 XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
Herbert Xuc6581a42007-11-13 21:43:43 -0800215 kfree_skb(skb);
216 return err;
217 }
218 }
219
Eric W. Biederman0c4b51f2015-09-15 20:04:18 -0500220 return xfrm_output2(net, sk, skb);
Herbert Xuc6581a42007-11-13 21:43:43 -0800221}
Fabian Frederickfc680862014-05-12 19:54:34 +0200222EXPORT_SYMBOL_GPL(xfrm_output);
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700223
224int xfrm_inner_extract_output(struct xfrm_state *x, struct sk_buff *skb)
225{
226 struct xfrm_mode *inner_mode;
227 if (x->sel.family == AF_UNSPEC)
228 inner_mode = xfrm_ip2inner_mode(x,
Eric Dumazetadf30902009-06-02 05:19:30 +0000229 xfrm_af2proto(skb_dst(skb)->ops->family));
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700230 else
231 inner_mode = x->inner_mode;
232
233 if (inner_mode == NULL)
234 return -EAFNOSUPPORT;
235 return inner_mode->afinfo->extract_output(x, skb);
236}
Fabian Frederickfc680862014-05-12 19:54:34 +0200237EXPORT_SYMBOL_GPL(xfrm_inner_extract_output);
Kazunori MIYAZAWAdf9dcb42008-03-24 14:51:51 -0700238
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200239void xfrm_local_error(struct sk_buff *skb, int mtu)
240{
Hannes Frederic Sowa844d4872013-08-18 13:47:01 +0200241 unsigned int proto;
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200242 struct xfrm_state_afinfo *afinfo;
243
Hannes Frederic Sowa844d4872013-08-18 13:47:01 +0200244 if (skb->protocol == htons(ETH_P_IP))
245 proto = AF_INET;
246 else if (skb->protocol == htons(ETH_P_IPV6))
247 proto = AF_INET6;
248 else
249 return;
250
251 afinfo = xfrm_state_get_afinfo(proto);
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200252 if (!afinfo)
253 return;
254
255 afinfo->local_error(skb, mtu);
256 xfrm_state_put_afinfo(afinfo);
257}
Hannes Frederic Sowa628e3412013-08-14 13:05:23 +0200258EXPORT_SYMBOL_GPL(xfrm_local_error);