blob: d95631d0924899f17549e69801567bed076491b9 [file] [log] [blame]
Joe Perchesafd465032012-03-12 07:03:32 +00001#define pr_fmt(fmt) "IPsec: " fmt
2
Herbert Xu38320c72008-01-28 19:35:05 -08003#include <crypto/aead.h>
4#include <crypto/authenc.h>
Herbert Xu6b7326c2006-07-30 15:41:01 +10005#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07006#include <linux/module.h>
7#include <net/ip.h>
8#include <net/xfrm.h>
9#include <net/esp.h>
Adrian Bunk72998d82007-10-26 22:53:58 -070010#include <linux/scatterlist.h>
Herbert Xua02a6422005-10-10 21:11:08 -070011#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/pfkeyv2.h>
Herbert Xu38320c72008-01-28 19:35:05 -080013#include <linux/rtnetlink.h>
14#include <linux/slab.h>
Herbert Xub7c65382007-10-09 13:33:35 -070015#include <linux/spinlock.h>
Thomas Graf2017a722007-12-10 16:53:05 -080016#include <linux/in6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <net/icmp.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020018#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <net/udp.h>
20
Herbert Xu38320c72008-01-28 19:35:05 -080021struct esp_skb_cb {
22 struct xfrm_skb_cb xfrm;
23 void *tmp;
24};
25
Herbert Xu962fcef2016-06-18 13:03:36 +080026struct esp_output_extra {
27 __be32 seqhi;
28 u32 esphoff;
29};
30
Herbert Xu38320c72008-01-28 19:35:05 -080031#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
32
Martin Willid979e202010-12-08 04:37:50 +000033static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
34
Herbert Xu38320c72008-01-28 19:35:05 -080035/*
36 * Allocate an AEAD request structure with extra space for SG and IV.
37 *
38 * For alignment considerations the IV is placed at the front, followed
39 * by the request and finally the SG list.
40 *
41 * TODO: Use spare space in skb for this where possible.
42 */
Herbert Xu962fcef2016-06-18 13:03:36 +080043static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
Herbert Xu38320c72008-01-28 19:35:05 -080044{
45 unsigned int len;
46
Herbert Xu962fcef2016-06-18 13:03:36 +080047 len = extralen;
Steffen Klassert0dc49e92011-03-08 00:07:14 +000048
49 len += crypto_aead_ivsize(aead);
50
Herbert Xu38320c72008-01-28 19:35:05 -080051 if (len) {
52 len += crypto_aead_alignmask(aead) &
53 ~(crypto_tfm_ctx_alignment() - 1);
54 len = ALIGN(len, crypto_tfm_ctx_alignment());
55 }
56
Herbert Xu7021b2e2015-05-27 16:03:46 +080057 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
Herbert Xu38320c72008-01-28 19:35:05 -080058 len = ALIGN(len, __alignof__(struct scatterlist));
59
60 len += sizeof(struct scatterlist) * nfrags;
61
62 return kmalloc(len, GFP_ATOMIC);
63}
64
Herbert Xu962fcef2016-06-18 13:03:36 +080065static inline void *esp_tmp_extra(void *tmp)
Steffen Klassert0dc49e92011-03-08 00:07:14 +000066{
Herbert Xu962fcef2016-06-18 13:03:36 +080067 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
Steffen Klassert0dc49e92011-03-08 00:07:14 +000068}
Herbert Xu962fcef2016-06-18 13:03:36 +080069
70static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
Herbert Xu38320c72008-01-28 19:35:05 -080071{
72 return crypto_aead_ivsize(aead) ?
Herbert Xu962fcef2016-06-18 13:03:36 +080073 PTR_ALIGN((u8 *)tmp + extralen,
74 crypto_aead_alignmask(aead) + 1) : tmp + extralen;
Herbert Xu38320c72008-01-28 19:35:05 -080075}
76
Herbert Xu38320c72008-01-28 19:35:05 -080077static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
78{
79 struct aead_request *req;
80
81 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
82 crypto_tfm_ctx_alignment());
83 aead_request_set_tfm(req, aead);
84 return req;
85}
86
87static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
88 struct aead_request *req)
89{
90 return (void *)ALIGN((unsigned long)(req + 1) +
91 crypto_aead_reqsize(aead),
92 __alignof__(struct scatterlist));
93}
94
Herbert Xu38320c72008-01-28 19:35:05 -080095static void esp_output_done(struct crypto_async_request *base, int err)
96{
97 struct sk_buff *skb = base->data;
98
99 kfree(ESP_SKB_CB(skb)->tmp);
100 xfrm_output_resume(skb, err);
101}
102
Herbert Xu7021b2e2015-05-27 16:03:46 +0800103/* Move ESP header back into place. */
104static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
105{
106 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
107 void *tmp = ESP_SKB_CB(skb)->tmp;
Herbert Xu962fcef2016-06-18 13:03:36 +0800108 __be32 *seqhi = esp_tmp_extra(tmp);
Herbert Xu7021b2e2015-05-27 16:03:46 +0800109
110 esph->seq_no = esph->spi;
111 esph->spi = *seqhi;
112}
113
114static void esp_output_restore_header(struct sk_buff *skb)
115{
Herbert Xu962fcef2016-06-18 13:03:36 +0800116 void *tmp = ESP_SKB_CB(skb)->tmp;
117 struct esp_output_extra *extra = esp_tmp_extra(tmp);
118
119 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
120 sizeof(__be32));
Herbert Xu7021b2e2015-05-27 16:03:46 +0800121}
122
123static void esp_output_done_esn(struct crypto_async_request *base, int err)
124{
125 struct sk_buff *skb = base->data;
126
127 esp_output_restore_header(skb);
128 esp_output_done(base, err);
129}
130
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
132{
133 int err;
Herbert Xu962fcef2016-06-18 13:03:36 +0800134 struct esp_output_extra *extra;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 struct ip_esp_hdr *esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800136 struct crypto_aead *aead;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800137 struct aead_request *req;
Herbert Xu38320c72008-01-28 19:35:05 -0800138 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800140 void *tmp;
141 u8 *iv;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700142 u8 *tail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 int blksize;
144 int clen;
145 int alen;
Martin Willid979e202010-12-08 04:37:50 +0000146 int plen;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800147 int ivlen;
Martin Willid979e202010-12-08 04:37:50 +0000148 int tfclen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000150 int assoclen;
Herbert Xu962fcef2016-06-18 13:03:36 +0800151 int extralen;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800152 __be64 seqno;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Herbert Xu7b277b12007-10-10 15:44:06 -0700154 /* skb is pure payload to encrypt */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
Mathias Krause1c5ad132013-10-18 12:09:05 +0200156 aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800157 alen = crypto_aead_authsize(aead);
Herbert Xu7021b2e2015-05-27 16:03:46 +0800158 ivlen = crypto_aead_ivsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
Martin Willid979e202010-12-08 04:37:50 +0000160 tfclen = 0;
161 if (x->tfcpad) {
162 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
163 u32 padto;
164
165 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
166 if (skb->len < padto)
167 tfclen = padto - skb->len;
168 }
Herbert Xu38320c72008-01-28 19:35:05 -0800169 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willid979e202010-12-08 04:37:50 +0000170 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Martin Willid979e202010-12-08 04:37:50 +0000171 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800172
Martin Willid979e202010-12-08 04:37:50 +0000173 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
174 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800176 nfrags = err;
177
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000178 assoclen = sizeof(*esph);
Herbert Xu962fcef2016-06-18 13:03:36 +0800179 extralen = 0;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000180
181 if (x->props.flags & XFRM_STATE_ESN) {
Herbert Xu962fcef2016-06-18 13:03:36 +0800182 extralen += sizeof(*extra);
183 assoclen += sizeof(__be32);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000184 }
185
Herbert Xu962fcef2016-06-18 13:03:36 +0800186 tmp = esp_alloc_tmp(aead, nfrags, extralen);
Wei Yongjun06848c12013-04-13 15:49:03 +0000187 if (!tmp) {
188 err = -ENOMEM;
Herbert Xu38320c72008-01-28 19:35:05 -0800189 goto error;
Wei Yongjun06848c12013-04-13 15:49:03 +0000190 }
Herbert Xu38320c72008-01-28 19:35:05 -0800191
Herbert Xu962fcef2016-06-18 13:03:36 +0800192 extra = esp_tmp_extra(tmp);
193 iv = esp_tmp_iv(aead, tmp, extralen);
Herbert Xu7021b2e2015-05-27 16:03:46 +0800194 req = esp_tmp_req(aead, iv);
195 sg = esp_req_sg(aead, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
197 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700198 tail = skb_tail_pointer(trailer);
Martin Willid979e202010-12-08 04:37:50 +0000199 if (tfclen) {
200 memset(tail, 0, tfclen);
201 tail += tfclen;
202 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 do {
204 int i;
Martin Willid979e202010-12-08 04:37:50 +0000205 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700206 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 } while (0);
Martin Willid979e202010-12-08 04:37:50 +0000208 tail[plen - 2] = plen - 2;
209 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800210 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
Herbert Xu7b277b12007-10-10 15:44:06 -0700212 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700213 esph = ip_esp_hdr(skb);
Herbert Xu37fedd32007-10-10 15:44:44 -0700214 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215
216 /* this is non-NULL only with UDP Encapsulation */
217 if (x->encap) {
218 struct xfrm_encap_tmpl *encap = x->encap;
219 struct udphdr *uh;
Al Virod5a0a1e2006-11-08 00:23:14 -0800220 __be32 *udpdata32;
Al Viro5e226e42008-03-17 22:50:23 -0700221 __be16 sport, dport;
Herbert Xu38320c72008-01-28 19:35:05 -0800222 int encap_type;
223
224 spin_lock_bh(&x->lock);
225 sport = encap->encap_sport;
226 dport = encap->encap_dport;
227 encap_type = encap->encap_type;
228 spin_unlock_bh(&x->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 uh = (struct udphdr *)esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800231 uh->source = sport;
232 uh->dest = dport;
233 uh->len = htons(skb->len - skb_transport_offset(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 uh->check = 0;
235
Herbert Xu38320c72008-01-28 19:35:05 -0800236 switch (encap_type) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 default:
238 case UDP_ENCAP_ESPINUDP:
239 esph = (struct ip_esp_hdr *)(uh + 1);
240 break;
241 case UDP_ENCAP_ESPINUDP_NON_IKE:
Al Virod5a0a1e2006-11-08 00:23:14 -0800242 udpdata32 = (__be32 *)(uh + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 udpdata32[0] = udpdata32[1] = 0;
244 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
245 break;
246 }
247
Herbert Xu37fedd32007-10-10 15:44:44 -0700248 *skb_mac_header(skb) = IPPROTO_UDP;
249 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
Steffen Klassert1ce36442011-03-08 00:06:31 +0000251 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Herbert Xu7021b2e2015-05-27 16:03:46 +0800253 aead_request_set_callback(req, 0, esp_output_done, skb);
254
255 /* For ESN we move the header forward by 4 bytes to
256 * accomodate the high bits. We will move it back after
257 * encryption.
258 */
259 if ((x->props.flags & XFRM_STATE_ESN)) {
Herbert Xu962fcef2016-06-18 13:03:36 +0800260 extra->esphoff = (unsigned char *)esph -
261 skb_transport_header(skb);
262 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
263 extra->seqhi = esph->spi;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800264 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
265 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
266 }
267
268 esph->spi = x->id.spi;
269
Herbert Xu38320c72008-01-28 19:35:05 -0800270 sg_init_table(sg, nfrags);
271 skb_to_sgvec(skb, sg,
Herbert Xu7021b2e2015-05-27 16:03:46 +0800272 (unsigned char *)esph - skb->data,
273 assoclen + ivlen + clen + alen);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000274
Herbert Xu7021b2e2015-05-27 16:03:46 +0800275 aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
276 aead_request_set_ad(req, assoclen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
Herbert Xu7021b2e2015-05-27 16:03:46 +0800278 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
279 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
280
281 memset(iv, 0, ivlen);
282 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
283 min(ivlen, 8));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
Herbert Xu38320c72008-01-28 19:35:05 -0800285 ESP_SKB_CB(skb)->tmp = tmp;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800286 err = crypto_aead_encrypt(req);
287
288 switch (err) {
289 case -EINPROGRESS:
Herbert Xu38320c72008-01-28 19:35:05 -0800290 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
Herbert Xu7021b2e2015-05-27 16:03:46 +0800292 case -EBUSY:
Herbert Xu38320c72008-01-28 19:35:05 -0800293 err = NET_XMIT_DROP;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800294 break;
295
296 case 0:
297 if ((x->props.flags & XFRM_STATE_ESN))
298 esp_output_restore_header(skb);
299 }
Herbert Xu6b7326c2006-07-30 15:41:01 +1000300
Herbert Xu38320c72008-01-28 19:35:05 -0800301 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700302
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303error:
304 return err;
305}
306
Herbert Xu38320c72008-01-28 19:35:05 -0800307static int esp_input_done2(struct sk_buff *skb, int err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308{
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000309 const struct iphdr *iph;
Herbert Xu38320c72008-01-28 19:35:05 -0800310 struct xfrm_state *x = xfrm_input_state(skb);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200311 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800312 int alen = crypto_aead_authsize(aead);
313 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
314 int elen = skb->len - hlen;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700315 int ihl;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800316 u8 nexthdr[2];
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800317 int padlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
Herbert Xu38320c72008-01-28 19:35:05 -0800319 kfree(ESP_SKB_CB(skb)->tmp);
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800320
Herbert Xu6b7326c2006-07-30 15:41:01 +1000321 if (unlikely(err))
Herbert Xu668dc8a2007-12-16 15:55:02 -0800322 goto out;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800323
324 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
325 BUG();
326
Herbert Xu668dc8a2007-12-16 15:55:02 -0800327 err = -EINVAL;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800328 padlen = nexthdr[0];
Herbert Xu38320c72008-01-28 19:35:05 -0800329 if (padlen + 2 + alen >= elen)
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800330 goto out;
331
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900332 /* ... check padding bits here. Silly. :-) */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800333
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700334 iph = ip_hdr(skb);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700335 ihl = iph->ihl * 4;
336
Herbert Xu752c1f42006-02-27 13:00:40 -0800337 if (x->encap) {
338 struct xfrm_encap_tmpl *encap = x->encap;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700339 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
Herbert Xu752c1f42006-02-27 13:00:40 -0800340
341 /*
342 * 1) if the NAT-T peer's IP or port changed then
343 * advertize the change to the keying daemon.
344 * This is an inbound SA, so just compare
345 * SRC ports.
346 */
347 if (iph->saddr != x->props.saddr.a4 ||
348 uh->source != encap->encap_sport) {
349 xfrm_address_t ipaddr;
350
351 ipaddr.a4 = iph->saddr;
352 km_new_mapping(x, &ipaddr, uh->source);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900353
Herbert Xu752c1f42006-02-27 13:00:40 -0800354 /* XXX: perhaps add an extra
355 * policy check here, to see
356 * if we should allow or
357 * reject a packet from a
358 * different source
359 * address/port.
360 */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800361 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900362
Herbert Xu752c1f42006-02-27 13:00:40 -0800363 /*
364 * 2) ignore UDP/TCP checksums in case
365 * of NAT-T in Transport Mode, or
366 * perform other post-processing fixes
367 * as per draft-ietf-ipsec-udp-encaps-06,
368 * section 3.1.2
369 */
Herbert Xu8bd17072007-10-10 15:41:41 -0700370 if (x->props.mode == XFRM_MODE_TRANSPORT)
Herbert Xu752c1f42006-02-27 13:00:40 -0800371 skb->ip_summed = CHECKSUM_UNNECESSARY;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800372 }
373
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800374 pskb_trim(skb, skb->len - alen - padlen - 2);
Herbert Xu38320c72008-01-28 19:35:05 -0800375 __skb_pull(skb, hlen);
Li RongQing7143dfa2012-12-28 16:07:16 +0800376 if (x->props.mode == XFRM_MODE_TUNNEL)
377 skb_reset_transport_header(skb);
378 else
379 skb_set_transport_header(skb, -ihl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
Herbert Xu38320c72008-01-28 19:35:05 -0800381 err = nexthdr[1];
382
383 /* RFC4303: Drop dummy packets without any error */
384 if (err == IPPROTO_NONE)
385 err = -EINVAL;
386
387out:
388 return err;
389}
390
391static void esp_input_done(struct crypto_async_request *base, int err)
392{
393 struct sk_buff *skb = base->data;
394
395 xfrm_input_resume(skb, esp_input_done2(skb, err));
396}
397
Herbert Xu7021b2e2015-05-27 16:03:46 +0800398static void esp_input_restore_header(struct sk_buff *skb)
399{
400 esp_restore_header(skb, 0);
401 __skb_pull(skb, 4);
402}
403
404static void esp_input_done_esn(struct crypto_async_request *base, int err)
405{
406 struct sk_buff *skb = base->data;
407
408 esp_input_restore_header(skb);
409 esp_input_done(base, err);
410}
411
Herbert Xu38320c72008-01-28 19:35:05 -0800412/*
413 * Note: detecting truncated vs. non-truncated authentication data is very
414 * expensive, so we only support truncated data, which is the recommended
415 * and common case.
416 */
417static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
418{
419 struct ip_esp_hdr *esph;
Mathias Krause1c5ad132013-10-18 12:09:05 +0200420 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800421 struct aead_request *req;
422 struct sk_buff *trailer;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800423 int ivlen = crypto_aead_ivsize(aead);
424 int elen = skb->len - sizeof(*esph) - ivlen;
Herbert Xu38320c72008-01-28 19:35:05 -0800425 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000426 int assoclen;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000427 int seqhilen;
428 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800429 void *tmp;
430 u8 *iv;
431 struct scatterlist *sg;
Herbert Xu38320c72008-01-28 19:35:05 -0800432 int err = -EINVAL;
433
Herbert Xu7021b2e2015-05-27 16:03:46 +0800434 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen))
Herbert Xu38320c72008-01-28 19:35:05 -0800435 goto out;
436
437 if (elen <= 0)
438 goto out;
439
Fabian Frederick05006e82014-11-04 22:54:36 +0100440 err = skb_cow_data(skb, 0, &trailer);
441 if (err < 0)
Herbert Xu38320c72008-01-28 19:35:05 -0800442 goto out;
Fabian Frederick05006e82014-11-04 22:54:36 +0100443
Herbert Xu38320c72008-01-28 19:35:05 -0800444 nfrags = err;
445
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000446 assoclen = sizeof(*esph);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000447 seqhilen = 0;
448
449 if (x->props.flags & XFRM_STATE_ESN) {
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000450 seqhilen += sizeof(__be32);
451 assoclen += seqhilen;
452 }
453
Herbert Xu38320c72008-01-28 19:35:05 -0800454 err = -ENOMEM;
Herbert Xu7021b2e2015-05-27 16:03:46 +0800455 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800456 if (!tmp)
457 goto out;
458
459 ESP_SKB_CB(skb)->tmp = tmp;
Herbert Xu962fcef2016-06-18 13:03:36 +0800460 seqhi = esp_tmp_extra(tmp);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000461 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800462 req = esp_tmp_req(aead, iv);
Herbert Xu7021b2e2015-05-27 16:03:46 +0800463 sg = esp_req_sg(aead, req);
Herbert Xu38320c72008-01-28 19:35:05 -0800464
465 skb->ip_summed = CHECKSUM_NONE;
466
467 esph = (struct ip_esp_hdr *)skb->data;
468
Herbert Xu7021b2e2015-05-27 16:03:46 +0800469 aead_request_set_callback(req, 0, esp_input_done, skb);
470
471 /* For ESN we move the header forward by 4 bytes to
472 * accomodate the high bits. We will move it back after
473 * decryption.
474 */
475 if ((x->props.flags & XFRM_STATE_ESN)) {
476 esph = (void *)skb_push(skb, 4);
477 *seqhi = esph->spi;
478 esph->spi = esph->seq_no;
479 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.input.hi);
480 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
481 }
Herbert Xu38320c72008-01-28 19:35:05 -0800482
483 sg_init_table(sg, nfrags);
Herbert Xu7021b2e2015-05-27 16:03:46 +0800484 skb_to_sgvec(skb, sg, 0, skb->len);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000485
Herbert Xu7021b2e2015-05-27 16:03:46 +0800486 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
487 aead_request_set_ad(req, assoclen);
Herbert Xu38320c72008-01-28 19:35:05 -0800488
489 err = crypto_aead_decrypt(req);
490 if (err == -EINPROGRESS)
491 goto out;
492
Herbert Xu7021b2e2015-05-27 16:03:46 +0800493 if ((x->props.flags & XFRM_STATE_ESN))
494 esp_input_restore_header(skb);
495
Herbert Xu38320c72008-01-28 19:35:05 -0800496 err = esp_input_done2(skb, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497
498out:
Herbert Xu668dc8a2007-12-16 15:55:02 -0800499 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500}
501
Patrick McHardyc5c25232007-04-09 11:47:18 -0700502static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200504 struct crypto_aead *aead = x->data;
505 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000506 unsigned int net_adj;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507
Diego Beltrami0a694522006-10-03 23:47:05 -0700508 switch (x->props.mode) {
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000509 case XFRM_MODE_TRANSPORT:
510 case XFRM_MODE_BEET:
511 net_adj = sizeof(struct iphdr);
512 break;
Diego Beltrami0a694522006-10-03 23:47:05 -0700513 case XFRM_MODE_TUNNEL:
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000514 net_adj = 0;
Diego Beltrami0a694522006-10-03 23:47:05 -0700515 break;
516 default:
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000517 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 }
Diego Beltrami0a694522006-10-03 23:47:05 -0700519
Mathias Krause1c5ad132013-10-18 12:09:05 +0200520 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
Mathias Krause123b0d12013-10-18 12:09:04 +0200521 net_adj) & ~(blksize - 1)) + net_adj - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522}
523
Steffen Klassert827789c2014-02-21 08:41:08 +0100524static int esp4_err(struct sk_buff *skb, u32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800526 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000527 const struct iphdr *iph = (const struct iphdr *)skb->data;
Jianjun Kongd93191002008-11-03 00:23:42 -0800528 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 struct xfrm_state *x;
530
David S. Miller55be7a92012-07-11 21:27:49 -0700531 switch (icmp_hdr(skb)->type) {
532 case ICMP_DEST_UNREACH:
533 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
Steffen Klassert827789c2014-02-21 08:41:08 +0100534 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -0700535 case ICMP_REDIRECT:
536 break;
537 default:
Steffen Klassert827789c2014-02-21 08:41:08 +0100538 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -0700539 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000541 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
542 esph->spi, IPPROTO_ESP, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 if (!x)
Steffen Klassert827789c2014-02-21 08:41:08 +0100544 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -0700545
Timo Teräs387aa652013-05-27 20:46:31 +0000546 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
David S. Miller55be7a92012-07-11 21:27:49 -0700547 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
Timo Teräs387aa652013-05-27 20:46:31 +0000548 else
David S. Miller55be7a92012-07-11 21:27:49 -0700549 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 xfrm_state_put(x);
Steffen Klassert827789c2014-02-21 08:41:08 +0100551
552 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553}
554
555static void esp_destroy(struct xfrm_state *x)
556{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200557 struct crypto_aead *aead = x->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558
Mathias Krause1c5ad132013-10-18 12:09:05 +0200559 if (!aead)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 return;
561
Mathias Krause1c5ad132013-10-18 12:09:05 +0200562 crypto_free_aead(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563}
564
Herbert Xu1a6509d2008-01-28 19:37:29 -0800565static int esp_init_aead(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566{
Herbert Xu7021b2e2015-05-27 16:03:46 +0800567 char aead_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu1a6509d2008-01-28 19:37:29 -0800568 struct crypto_aead *aead;
569 int err;
570
Herbert Xu7021b2e2015-05-27 16:03:46 +0800571 err = -ENAMETOOLONG;
572 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
573 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
574 goto error;
575
576 aead = crypto_alloc_aead(aead_name, 0, 0);
Herbert Xu1a6509d2008-01-28 19:37:29 -0800577 err = PTR_ERR(aead);
578 if (IS_ERR(aead))
579 goto error;
580
Mathias Krause1c5ad132013-10-18 12:09:05 +0200581 x->data = aead;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800582
583 err = crypto_aead_setkey(aead, x->aead->alg_key,
584 (x->aead->alg_key_len + 7) / 8);
585 if (err)
586 goto error;
587
588 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
589 if (err)
590 goto error;
591
592error:
593 return err;
594}
595
596static int esp_init_authenc(struct xfrm_state *x)
597{
Herbert Xu38320c72008-01-28 19:35:05 -0800598 struct crypto_aead *aead;
599 struct crypto_authenc_key_param *param;
600 struct rtattr *rta;
601 char *key;
602 char *p;
603 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800604 unsigned int keylen;
605 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
Herbert Xu1a6509d2008-01-28 19:37:29 -0800607 err = -EINVAL;
Ian Morris51456b22015-04-03 09:17:26 +0100608 if (!x->ealg)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800609 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800610
Herbert Xu1a6509d2008-01-28 19:37:29 -0800611 err = -ENAMETOOLONG;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000612
613 if ((x->props.flags & XFRM_STATE_ESN)) {
614 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
Herbert Xu7021b2e2015-05-27 16:03:46 +0800615 "%s%sauthencesn(%s,%s)%s",
616 x->geniv ?: "", x->geniv ? "(" : "",
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000617 x->aalg ? x->aalg->alg_name : "digest_null",
Herbert Xu7021b2e2015-05-27 16:03:46 +0800618 x->ealg->alg_name,
619 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000620 goto error;
621 } else {
622 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
Herbert Xu7021b2e2015-05-27 16:03:46 +0800623 "%s%sauthenc(%s,%s)%s",
624 x->geniv ?: "", x->geniv ? "(" : "",
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000625 x->aalg ? x->aalg->alg_name : "digest_null",
Herbert Xu7021b2e2015-05-27 16:03:46 +0800626 x->ealg->alg_name,
627 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000628 goto error;
629 }
Herbert Xu38320c72008-01-28 19:35:05 -0800630
631 aead = crypto_alloc_aead(authenc_name, 0, 0);
632 err = PTR_ERR(aead);
633 if (IS_ERR(aead))
634 goto error;
635
Mathias Krause1c5ad132013-10-18 12:09:05 +0200636 x->data = aead;
Herbert Xu38320c72008-01-28 19:35:05 -0800637
638 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
639 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
640 err = -ENOMEM;
641 key = kmalloc(keylen, GFP_KERNEL);
642 if (!key)
643 goto error;
644
645 p = key;
646 rta = (void *)p;
647 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
648 rta->rta_len = RTA_LENGTH(sizeof(*param));
649 param = RTA_DATA(rta);
650 p += RTA_SPACE(sizeof(*param));
651
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 if (x->aalg) {
653 struct xfrm_algo_desc *aalg_desc;
654
Herbert Xu38320c72008-01-28 19:35:05 -0800655 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
656 p += (x->aalg->alg_key_len + 7) / 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
658 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
659 BUG_ON(!aalg_desc);
660
Herbert Xu38320c72008-01-28 19:35:05 -0800661 err = -EINVAL;
Joe Perches45083492014-11-05 15:36:08 -0800662 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800663 crypto_aead_authsize(aead)) {
Joe Perches45083492014-11-05 15:36:08 -0800664 pr_info("ESP: %s digestsize %u != %hu\n",
665 x->aalg->alg_name,
666 crypto_aead_authsize(aead),
667 aalg_desc->uinfo.auth.icv_fullbits / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800668 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 }
670
Herbert Xu38320c72008-01-28 19:35:05 -0800671 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000672 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800673 if (err)
674 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 }
Herbert Xu4b7137f2007-10-08 17:13:44 -0700676
Herbert Xu38320c72008-01-28 19:35:05 -0800677 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
678 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
679
680 err = crypto_aead_setkey(aead, key, keylen);
681
682free_key:
683 kfree(key);
684
Herbert Xu1a6509d2008-01-28 19:37:29 -0800685error:
686 return err;
687}
688
689static int esp_init_state(struct xfrm_state *x)
690{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800691 struct crypto_aead *aead;
692 u32 align;
693 int err;
694
Mathias Krause1c5ad132013-10-18 12:09:05 +0200695 x->data = NULL;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800696
697 if (x->aead)
698 err = esp_init_aead(x);
699 else
700 err = esp_init_authenc(x);
701
Herbert Xu38320c72008-01-28 19:35:05 -0800702 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800704
Mathias Krause1c5ad132013-10-18 12:09:05 +0200705 aead = x->data;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800706
Herbert Xu38320c72008-01-28 19:35:05 -0800707 x->props.header_len = sizeof(struct ip_esp_hdr) +
708 crypto_aead_ivsize(aead);
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700709 if (x->props.mode == XFRM_MODE_TUNNEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 x->props.header_len += sizeof(struct iphdr);
Joakim Koskelaeb49e632008-08-06 02:39:30 -0700711 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
Patrick McHardyac758e32007-04-09 11:47:58 -0700712 x->props.header_len += IPV4_BEET_PHMAXLEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (x->encap) {
714 struct xfrm_encap_tmpl *encap = x->encap;
715
716 switch (encap->encap_type) {
717 default:
718 goto error;
719 case UDP_ENCAP_ESPINUDP:
720 x->props.header_len += sizeof(struct udphdr);
721 break;
722 case UDP_ENCAP_ESPINUDP_NON_IKE:
723 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
724 break;
725 }
726 }
Herbert Xu38320c72008-01-28 19:35:05 -0800727
728 align = ALIGN(crypto_aead_blocksize(aead), 4);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200729 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730
731error:
Herbert Xu38320c72008-01-28 19:35:05 -0800732 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733}
734
Steffen Klassert827789c2014-02-21 08:41:08 +0100735static int esp4_rcv_cb(struct sk_buff *skb, int err)
736{
737 return 0;
738}
739
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800740static const struct xfrm_type esp_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741{
742 .description = "ESP4",
743 .owner = THIS_MODULE,
744 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700745 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 .init_state = esp_init_state,
747 .destructor = esp_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700748 .get_mtu = esp4_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 .input = esp_input,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 .output = esp_output
751};
752
Steffen Klassert827789c2014-02-21 08:41:08 +0100753static struct xfrm4_protocol esp4_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 .handler = xfrm4_rcv,
Steffen Klassert827789c2014-02-21 08:41:08 +0100755 .input_handler = xfrm_input,
756 .cb_handler = esp4_rcv_cb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 .err_handler = esp4_err,
Steffen Klassert827789c2014-02-21 08:41:08 +0100758 .priority = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759};
760
761static int __init esp4_init(void)
762{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000764 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 return -EAGAIN;
766 }
Steffen Klassert827789c2014-02-21 08:41:08 +0100767 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000768 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 xfrm_unregister_type(&esp_type, AF_INET);
770 return -EAGAIN;
771 }
772 return 0;
773}
774
775static void __exit esp4_fini(void)
776{
Steffen Klassert827789c2014-02-21 08:41:08 +0100777 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000778 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000780 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781}
782
783module_init(esp4_init);
784module_exit(esp4_fini);
785MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700786MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);