blob: 7785b28061acfecd59e4ece70815edb3dcc58977 [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
26#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
27
Martin Willid979e202010-12-08 04:37:50 +000028static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
29
Herbert Xu38320c72008-01-28 19:35:05 -080030/*
31 * Allocate an AEAD request structure with extra space for SG and IV.
32 *
33 * For alignment considerations the IV is placed at the front, followed
34 * by the request and finally the SG list.
35 *
36 * TODO: Use spare space in skb for this where possible.
37 */
Steffen Klassert0dc49e92011-03-08 00:07:14 +000038static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqhilen)
Herbert Xu38320c72008-01-28 19:35:05 -080039{
40 unsigned int len;
41
Steffen Klassert0dc49e92011-03-08 00:07:14 +000042 len = seqhilen;
43
44 len += crypto_aead_ivsize(aead);
45
Herbert Xu38320c72008-01-28 19:35:05 -080046 if (len) {
47 len += crypto_aead_alignmask(aead) &
48 ~(crypto_tfm_ctx_alignment() - 1);
49 len = ALIGN(len, crypto_tfm_ctx_alignment());
50 }
51
52 len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
53 len = ALIGN(len, __alignof__(struct scatterlist));
54
55 len += sizeof(struct scatterlist) * nfrags;
56
57 return kmalloc(len, GFP_ATOMIC);
58}
59
Steffen Klassert0dc49e92011-03-08 00:07:14 +000060static inline __be32 *esp_tmp_seqhi(void *tmp)
61{
62 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
63}
64static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
Herbert Xu38320c72008-01-28 19:35:05 -080065{
66 return crypto_aead_ivsize(aead) ?
Steffen Klassert0dc49e92011-03-08 00:07:14 +000067 PTR_ALIGN((u8 *)tmp + seqhilen,
68 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
Herbert Xu38320c72008-01-28 19:35:05 -080069}
70
71static inline struct aead_givcrypt_request *esp_tmp_givreq(
72 struct crypto_aead *aead, u8 *iv)
73{
74 struct aead_givcrypt_request *req;
75
76 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
77 crypto_tfm_ctx_alignment());
78 aead_givcrypt_set_tfm(req, aead);
79 return req;
80}
81
82static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
83{
84 struct aead_request *req;
85
86 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
87 crypto_tfm_ctx_alignment());
88 aead_request_set_tfm(req, aead);
89 return req;
90}
91
92static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
93 struct aead_request *req)
94{
95 return (void *)ALIGN((unsigned long)(req + 1) +
96 crypto_aead_reqsize(aead),
97 __alignof__(struct scatterlist));
98}
99
100static inline struct scatterlist *esp_givreq_sg(
101 struct crypto_aead *aead, struct aead_givcrypt_request *req)
102{
103 return (void *)ALIGN((unsigned long)(req + 1) +
104 crypto_aead_reqsize(aead),
105 __alignof__(struct scatterlist));
106}
107
108static void esp_output_done(struct crypto_async_request *base, int err)
109{
110 struct sk_buff *skb = base->data;
111
112 kfree(ESP_SKB_CB(skb)->tmp);
113 xfrm_output_resume(skb, err);
114}
115
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
117{
118 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 struct ip_esp_hdr *esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800120 struct crypto_aead *aead;
121 struct aead_givcrypt_request *req;
122 struct scatterlist *sg;
123 struct scatterlist *asg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800125 void *tmp;
126 u8 *iv;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700127 u8 *tail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 int blksize;
129 int clen;
130 int alen;
Martin Willid979e202010-12-08 04:37:50 +0000131 int plen;
132 int tfclen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000134 int assoclen;
135 int sglists;
136 int seqhilen;
137 __be32 *seqhi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
Herbert Xu7b277b12007-10-10 15:44:06 -0700139 /* skb is pure payload to encrypt */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140
Mathias Krause1c5ad132013-10-18 12:09:05 +0200141 aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800142 alen = crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
Martin Willid979e202010-12-08 04:37:50 +0000144 tfclen = 0;
145 if (x->tfcpad) {
146 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
147 u32 padto;
148
149 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
150 if (skb->len < padto)
151 tfclen = padto - skb->len;
152 }
Herbert Xu38320c72008-01-28 19:35:05 -0800153 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willid979e202010-12-08 04:37:50 +0000154 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Martin Willid979e202010-12-08 04:37:50 +0000155 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800156
Martin Willid979e202010-12-08 04:37:50 +0000157 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
158 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800160 nfrags = err;
161
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000162 assoclen = sizeof(*esph);
163 sglists = 1;
164 seqhilen = 0;
165
166 if (x->props.flags & XFRM_STATE_ESN) {
167 sglists += 2;
168 seqhilen += sizeof(__be32);
169 assoclen += seqhilen;
170 }
171
172 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Wei Yongjun06848c12013-04-13 15:49:03 +0000173 if (!tmp) {
174 err = -ENOMEM;
Herbert Xu38320c72008-01-28 19:35:05 -0800175 goto error;
Wei Yongjun06848c12013-04-13 15:49:03 +0000176 }
Herbert Xu38320c72008-01-28 19:35:05 -0800177
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000178 seqhi = esp_tmp_seqhi(tmp);
179 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800180 req = esp_tmp_givreq(aead, iv);
181 asg = esp_givreq_sg(aead, req);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000182 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
184 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700185 tail = skb_tail_pointer(trailer);
Martin Willid979e202010-12-08 04:37:50 +0000186 if (tfclen) {
187 memset(tail, 0, tfclen);
188 tail += tfclen;
189 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 do {
191 int i;
Martin Willid979e202010-12-08 04:37:50 +0000192 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700193 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 } while (0);
Martin Willid979e202010-12-08 04:37:50 +0000195 tail[plen - 2] = plen - 2;
196 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800197 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
Herbert Xu7b277b12007-10-10 15:44:06 -0700199 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700200 esph = ip_esp_hdr(skb);
Herbert Xu37fedd32007-10-10 15:44:44 -0700201 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203 /* this is non-NULL only with UDP Encapsulation */
204 if (x->encap) {
205 struct xfrm_encap_tmpl *encap = x->encap;
206 struct udphdr *uh;
Al Virod5a0a1e2006-11-08 00:23:14 -0800207 __be32 *udpdata32;
Al Viro5e226e42008-03-17 22:50:23 -0700208 __be16 sport, dport;
Herbert Xu38320c72008-01-28 19:35:05 -0800209 int encap_type;
210
211 spin_lock_bh(&x->lock);
212 sport = encap->encap_sport;
213 dport = encap->encap_dport;
214 encap_type = encap->encap_type;
215 spin_unlock_bh(&x->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216
217 uh = (struct udphdr *)esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800218 uh->source = sport;
219 uh->dest = dport;
220 uh->len = htons(skb->len - skb_transport_offset(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 uh->check = 0;
222
Herbert Xu38320c72008-01-28 19:35:05 -0800223 switch (encap_type) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 default:
225 case UDP_ENCAP_ESPINUDP:
226 esph = (struct ip_esp_hdr *)(uh + 1);
227 break;
228 case UDP_ENCAP_ESPINUDP_NON_IKE:
Al Virod5a0a1e2006-11-08 00:23:14 -0800229 udpdata32 = (__be32 *)(uh + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 udpdata32[0] = udpdata32[1] = 0;
231 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
232 break;
233 }
234
Herbert Xu37fedd32007-10-10 15:44:44 -0700235 *skb_mac_header(skb) = IPPROTO_UDP;
236 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 esph->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000239 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
Herbert Xu38320c72008-01-28 19:35:05 -0800241 sg_init_table(sg, nfrags);
242 skb_to_sgvec(skb, sg,
243 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
244 clen + alen);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000245
246 if ((x->props.flags & XFRM_STATE_ESN)) {
247 sg_init_table(asg, 3);
248 sg_set_buf(asg, &esph->spi, sizeof(__be32));
249 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
250 sg_set_buf(asg + 1, seqhi, seqhilen);
251 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
252 } else
253 sg_init_one(asg, esph, sizeof(*esph));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
Herbert Xu38320c72008-01-28 19:35:05 -0800255 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
256 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000257 aead_givcrypt_set_assoc(req, asg, assoclen);
Herbert Xub318e0e2008-02-12 22:50:35 -0800258 aead_givcrypt_set_giv(req, esph->enc_data,
Steffen Klassert1ce36442011-03-08 00:06:31 +0000259 XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Herbert Xu38320c72008-01-28 19:35:05 -0800261 ESP_SKB_CB(skb)->tmp = tmp;
262 err = crypto_aead_givencrypt(req);
263 if (err == -EINPROGRESS)
264 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
Herbert Xu38320c72008-01-28 19:35:05 -0800266 if (err == -EBUSY)
267 err = NET_XMIT_DROP;
Herbert Xu6b7326c2006-07-30 15:41:01 +1000268
Herbert Xu38320c72008-01-28 19:35:05 -0800269 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700270
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271error:
272 return err;
273}
274
Herbert Xu38320c72008-01-28 19:35:05 -0800275static int esp_input_done2(struct sk_buff *skb, int err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000277 const struct iphdr *iph;
Herbert Xu38320c72008-01-28 19:35:05 -0800278 struct xfrm_state *x = xfrm_input_state(skb);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200279 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800280 int alen = crypto_aead_authsize(aead);
281 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
282 int elen = skb->len - hlen;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700283 int ihl;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800284 u8 nexthdr[2];
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800285 int padlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
Herbert Xu38320c72008-01-28 19:35:05 -0800287 kfree(ESP_SKB_CB(skb)->tmp);
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800288
Herbert Xu6b7326c2006-07-30 15:41:01 +1000289 if (unlikely(err))
Herbert Xu668dc8a2007-12-16 15:55:02 -0800290 goto out;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800291
292 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
293 BUG();
294
Herbert Xu668dc8a2007-12-16 15:55:02 -0800295 err = -EINVAL;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800296 padlen = nexthdr[0];
Herbert Xu38320c72008-01-28 19:35:05 -0800297 if (padlen + 2 + alen >= elen)
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800298 goto out;
299
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900300 /* ... check padding bits here. Silly. :-) */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800301
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700302 iph = ip_hdr(skb);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700303 ihl = iph->ihl * 4;
304
Herbert Xu752c1f42006-02-27 13:00:40 -0800305 if (x->encap) {
306 struct xfrm_encap_tmpl *encap = x->encap;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700307 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
Herbert Xu752c1f42006-02-27 13:00:40 -0800308
309 /*
310 * 1) if the NAT-T peer's IP or port changed then
311 * advertize the change to the keying daemon.
312 * This is an inbound SA, so just compare
313 * SRC ports.
314 */
315 if (iph->saddr != x->props.saddr.a4 ||
316 uh->source != encap->encap_sport) {
317 xfrm_address_t ipaddr;
318
319 ipaddr.a4 = iph->saddr;
320 km_new_mapping(x, &ipaddr, uh->source);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900321
Herbert Xu752c1f42006-02-27 13:00:40 -0800322 /* XXX: perhaps add an extra
323 * policy check here, to see
324 * if we should allow or
325 * reject a packet from a
326 * different source
327 * address/port.
328 */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800329 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900330
Herbert Xu752c1f42006-02-27 13:00:40 -0800331 /*
332 * 2) ignore UDP/TCP checksums in case
333 * of NAT-T in Transport Mode, or
334 * perform other post-processing fixes
335 * as per draft-ietf-ipsec-udp-encaps-06,
336 * section 3.1.2
337 */
Herbert Xu8bd17072007-10-10 15:41:41 -0700338 if (x->props.mode == XFRM_MODE_TRANSPORT)
Herbert Xu752c1f42006-02-27 13:00:40 -0800339 skb->ip_summed = CHECKSUM_UNNECESSARY;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800340 }
341
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800342 pskb_trim(skb, skb->len - alen - padlen - 2);
Herbert Xu38320c72008-01-28 19:35:05 -0800343 __skb_pull(skb, hlen);
Li RongQing7143dfa2012-12-28 16:07:16 +0800344 if (x->props.mode == XFRM_MODE_TUNNEL)
345 skb_reset_transport_header(skb);
346 else
347 skb_set_transport_header(skb, -ihl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
Herbert Xu38320c72008-01-28 19:35:05 -0800349 err = nexthdr[1];
350
351 /* RFC4303: Drop dummy packets without any error */
352 if (err == IPPROTO_NONE)
353 err = -EINVAL;
354
355out:
356 return err;
357}
358
359static void esp_input_done(struct crypto_async_request *base, int err)
360{
361 struct sk_buff *skb = base->data;
362
363 xfrm_input_resume(skb, esp_input_done2(skb, err));
364}
365
366/*
367 * Note: detecting truncated vs. non-truncated authentication data is very
368 * expensive, so we only support truncated data, which is the recommended
369 * and common case.
370 */
371static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
372{
373 struct ip_esp_hdr *esph;
Mathias Krause1c5ad132013-10-18 12:09:05 +0200374 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800375 struct aead_request *req;
376 struct sk_buff *trailer;
377 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
378 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000379 int assoclen;
380 int sglists;
381 int seqhilen;
382 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800383 void *tmp;
384 u8 *iv;
385 struct scatterlist *sg;
386 struct scatterlist *asg;
387 int err = -EINVAL;
388
Thomas Graf920fc942008-03-27 16:08:03 -0700389 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
Herbert Xu38320c72008-01-28 19:35:05 -0800390 goto out;
391
392 if (elen <= 0)
393 goto out;
394
395 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
396 goto out;
397 nfrags = err;
398
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000399 assoclen = sizeof(*esph);
400 sglists = 1;
401 seqhilen = 0;
402
403 if (x->props.flags & XFRM_STATE_ESN) {
404 sglists += 2;
405 seqhilen += sizeof(__be32);
406 assoclen += seqhilen;
407 }
408
Herbert Xu38320c72008-01-28 19:35:05 -0800409 err = -ENOMEM;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000410 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800411 if (!tmp)
412 goto out;
413
414 ESP_SKB_CB(skb)->tmp = tmp;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000415 seqhi = esp_tmp_seqhi(tmp);
416 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800417 req = esp_tmp_req(aead, iv);
418 asg = esp_req_sg(aead, req);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000419 sg = asg + sglists;
Herbert Xu38320c72008-01-28 19:35:05 -0800420
421 skb->ip_summed = CHECKSUM_NONE;
422
423 esph = (struct ip_esp_hdr *)skb->data;
424
425 /* Get ivec. This can be wrong, check against another impls. */
426 iv = esph->enc_data;
427
428 sg_init_table(sg, nfrags);
429 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000430
431 if ((x->props.flags & XFRM_STATE_ESN)) {
432 sg_init_table(asg, 3);
433 sg_set_buf(asg, &esph->spi, sizeof(__be32));
434 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
435 sg_set_buf(asg + 1, seqhi, seqhilen);
436 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
437 } else
438 sg_init_one(asg, esph, sizeof(*esph));
Herbert Xu38320c72008-01-28 19:35:05 -0800439
440 aead_request_set_callback(req, 0, esp_input_done, skb);
441 aead_request_set_crypt(req, sg, sg, elen, iv);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000442 aead_request_set_assoc(req, asg, assoclen);
Herbert Xu38320c72008-01-28 19:35:05 -0800443
444 err = crypto_aead_decrypt(req);
445 if (err == -EINPROGRESS)
446 goto out;
447
448 err = esp_input_done2(skb, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
450out:
Herbert Xu668dc8a2007-12-16 15:55:02 -0800451 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452}
453
Patrick McHardyc5c25232007-04-09 11:47:18 -0700454static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200456 struct crypto_aead *aead = x->data;
457 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000458 unsigned int net_adj;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
Diego Beltrami0a694522006-10-03 23:47:05 -0700460 switch (x->props.mode) {
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000461 case XFRM_MODE_TRANSPORT:
462 case XFRM_MODE_BEET:
463 net_adj = sizeof(struct iphdr);
464 break;
Diego Beltrami0a694522006-10-03 23:47:05 -0700465 case XFRM_MODE_TUNNEL:
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000466 net_adj = 0;
Diego Beltrami0a694522006-10-03 23:47:05 -0700467 break;
468 default:
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000469 BUG();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 }
Diego Beltrami0a694522006-10-03 23:47:05 -0700471
Mathias Krause1c5ad132013-10-18 12:09:05 +0200472 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
Mathias Krause123b0d12013-10-18 12:09:04 +0200473 net_adj) & ~(blksize - 1)) + net_adj - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474}
475
476static void esp4_err(struct sk_buff *skb, u32 info)
477{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800478 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000479 const struct iphdr *iph = (const struct iphdr *)skb->data;
Jianjun Kongd93191002008-11-03 00:23:42 -0800480 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 struct xfrm_state *x;
482
David S. Miller55be7a92012-07-11 21:27:49 -0700483 switch (icmp_hdr(skb)->type) {
484 case ICMP_DEST_UNREACH:
485 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
486 return;
487 case ICMP_REDIRECT:
488 break;
489 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 return;
David S. Miller55be7a92012-07-11 21:27:49 -0700491 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000493 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
494 esph->spi, IPPROTO_ESP, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 if (!x)
496 return;
David S. Miller55be7a92012-07-11 21:27:49 -0700497
Timo Teräs387aa652013-05-27 20:46:31 +0000498 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
David S. Miller55be7a92012-07-11 21:27:49 -0700499 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
Timo Teräs387aa652013-05-27 20:46:31 +0000500 else
David S. Miller55be7a92012-07-11 21:27:49 -0700501 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 xfrm_state_put(x);
503}
504
505static void esp_destroy(struct xfrm_state *x)
506{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200507 struct crypto_aead *aead = x->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
Mathias Krause1c5ad132013-10-18 12:09:05 +0200509 if (!aead)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 return;
511
Mathias Krause1c5ad132013-10-18 12:09:05 +0200512 crypto_free_aead(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513}
514
Herbert Xu1a6509d2008-01-28 19:37:29 -0800515static int esp_init_aead(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800517 struct crypto_aead *aead;
518 int err;
519
520 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
521 err = PTR_ERR(aead);
522 if (IS_ERR(aead))
523 goto error;
524
Mathias Krause1c5ad132013-10-18 12:09:05 +0200525 x->data = aead;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800526
527 err = crypto_aead_setkey(aead, x->aead->alg_key,
528 (x->aead->alg_key_len + 7) / 8);
529 if (err)
530 goto error;
531
532 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
533 if (err)
534 goto error;
535
536error:
537 return err;
538}
539
540static int esp_init_authenc(struct xfrm_state *x)
541{
Herbert Xu38320c72008-01-28 19:35:05 -0800542 struct crypto_aead *aead;
543 struct crypto_authenc_key_param *param;
544 struct rtattr *rta;
545 char *key;
546 char *p;
547 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800548 unsigned int keylen;
549 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550
Herbert Xu1a6509d2008-01-28 19:37:29 -0800551 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 if (x->ealg == NULL)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800553 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800554
Herbert Xu1a6509d2008-01-28 19:37:29 -0800555 err = -ENAMETOOLONG;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000556
557 if ((x->props.flags & XFRM_STATE_ESN)) {
558 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
559 "authencesn(%s,%s)",
560 x->aalg ? x->aalg->alg_name : "digest_null",
561 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
562 goto error;
563 } else {
564 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
565 "authenc(%s,%s)",
566 x->aalg ? x->aalg->alg_name : "digest_null",
567 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
568 goto error;
569 }
Herbert Xu38320c72008-01-28 19:35:05 -0800570
571 aead = crypto_alloc_aead(authenc_name, 0, 0);
572 err = PTR_ERR(aead);
573 if (IS_ERR(aead))
574 goto error;
575
Mathias Krause1c5ad132013-10-18 12:09:05 +0200576 x->data = aead;
Herbert Xu38320c72008-01-28 19:35:05 -0800577
578 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
579 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
580 err = -ENOMEM;
581 key = kmalloc(keylen, GFP_KERNEL);
582 if (!key)
583 goto error;
584
585 p = key;
586 rta = (void *)p;
587 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
588 rta->rta_len = RTA_LENGTH(sizeof(*param));
589 param = RTA_DATA(rta);
590 p += RTA_SPACE(sizeof(*param));
591
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 if (x->aalg) {
593 struct xfrm_algo_desc *aalg_desc;
594
Herbert Xu38320c72008-01-28 19:35:05 -0800595 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
596 p += (x->aalg->alg_key_len + 7) / 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
598 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
599 BUG_ON(!aalg_desc);
600
Herbert Xu38320c72008-01-28 19:35:05 -0800601 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800603 crypto_aead_authsize(aead)) {
Patrick McHardy64ce2072005-08-09 20:50:53 -0700604 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
605 x->aalg->alg_name,
Herbert Xu38320c72008-01-28 19:35:05 -0800606 crypto_aead_authsize(aead),
Patrick McHardy64ce2072005-08-09 20:50:53 -0700607 aalg_desc->uinfo.auth.icv_fullbits/8);
Herbert Xu38320c72008-01-28 19:35:05 -0800608 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 }
610
Herbert Xu38320c72008-01-28 19:35:05 -0800611 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000612 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800613 if (err)
614 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 }
Herbert Xu4b7137f2007-10-08 17:13:44 -0700616
Herbert Xu38320c72008-01-28 19:35:05 -0800617 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
618 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
619
620 err = crypto_aead_setkey(aead, key, keylen);
621
622free_key:
623 kfree(key);
624
Herbert Xu1a6509d2008-01-28 19:37:29 -0800625error:
626 return err;
627}
628
629static int esp_init_state(struct xfrm_state *x)
630{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800631 struct crypto_aead *aead;
632 u32 align;
633 int err;
634
Mathias Krause1c5ad132013-10-18 12:09:05 +0200635 x->data = NULL;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800636
637 if (x->aead)
638 err = esp_init_aead(x);
639 else
640 err = esp_init_authenc(x);
641
Herbert Xu38320c72008-01-28 19:35:05 -0800642 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800644
Mathias Krause1c5ad132013-10-18 12:09:05 +0200645 aead = x->data;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800646
Herbert Xu38320c72008-01-28 19:35:05 -0800647 x->props.header_len = sizeof(struct ip_esp_hdr) +
648 crypto_aead_ivsize(aead);
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700649 if (x->props.mode == XFRM_MODE_TUNNEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 x->props.header_len += sizeof(struct iphdr);
Joakim Koskelaeb49e632008-08-06 02:39:30 -0700651 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
Patrick McHardyac758e32007-04-09 11:47:58 -0700652 x->props.header_len += IPV4_BEET_PHMAXLEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 if (x->encap) {
654 struct xfrm_encap_tmpl *encap = x->encap;
655
656 switch (encap->encap_type) {
657 default:
658 goto error;
659 case UDP_ENCAP_ESPINUDP:
660 x->props.header_len += sizeof(struct udphdr);
661 break;
662 case UDP_ENCAP_ESPINUDP_NON_IKE:
663 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
664 break;
665 }
666 }
Herbert Xu38320c72008-01-28 19:35:05 -0800667
668 align = ALIGN(crypto_aead_blocksize(aead), 4);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200669 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
671error:
Herbert Xu38320c72008-01-28 19:35:05 -0800672 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673}
674
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800675static const struct xfrm_type esp_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676{
677 .description = "ESP4",
678 .owner = THIS_MODULE,
679 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700680 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 .init_state = esp_init_state,
682 .destructor = esp_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700683 .get_mtu = esp4_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 .input = esp_input,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 .output = esp_output
686};
687
Alexey Dobriyan32613092009-09-14 12:21:47 +0000688static const struct net_protocol esp4_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 .handler = xfrm4_rcv,
690 .err_handler = esp4_err,
691 .no_policy = 1,
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800692 .netns_ok = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693};
694
695static int __init esp4_init(void)
696{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000698 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 return -EAGAIN;
700 }
701 if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000702 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 xfrm_unregister_type(&esp_type, AF_INET);
704 return -EAGAIN;
705 }
706 return 0;
707}
708
709static void __exit esp4_fini(void)
710{
711 if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000712 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000714 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715}
716
717module_init(esp4_init);
718module_exit(esp4_fini);
719MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700720MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);