blob: a5b413416da33305bdf83ed2fd9e6104031e3687 [file] [log] [blame]
Herbert Xu38320c72008-01-28 19:35:05 -08001#include <crypto/aead.h>
2#include <crypto/authenc.h>
Herbert Xu6b7326c2006-07-30 15:41:01 +10003#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07004#include <linux/module.h>
5#include <net/ip.h>
6#include <net/xfrm.h>
7#include <net/esp.h>
Adrian Bunk72998d82007-10-26 22:53:58 -07008#include <linux/scatterlist.h>
Herbert Xua02a6422005-10-10 21:11:08 -07009#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/pfkeyv2.h>
Herbert Xu38320c72008-01-28 19:35:05 -080011#include <linux/rtnetlink.h>
12#include <linux/slab.h>
Herbert Xub7c65382007-10-09 13:33:35 -070013#include <linux/spinlock.h>
Thomas Graf2017a722007-12-10 16:53:05 -080014#include <linux/in6.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <net/icmp.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020016#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <net/udp.h>
18
Herbert Xu38320c72008-01-28 19:35:05 -080019struct esp_skb_cb {
20 struct xfrm_skb_cb xfrm;
21 void *tmp;
22};
23
24#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
25
Martin Willid979e202010-12-08 04:37:50 +000026static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
27
Herbert Xu38320c72008-01-28 19:35:05 -080028/*
29 * Allocate an AEAD request structure with extra space for SG and IV.
30 *
31 * For alignment considerations the IV is placed at the front, followed
32 * by the request and finally the SG list.
33 *
34 * TODO: Use spare space in skb for this where possible.
35 */
Steffen Klassert0dc49e92011-03-08 00:07:14 +000036static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqhilen)
Herbert Xu38320c72008-01-28 19:35:05 -080037{
38 unsigned int len;
39
Steffen Klassert0dc49e92011-03-08 00:07:14 +000040 len = seqhilen;
41
42 len += crypto_aead_ivsize(aead);
43
Herbert Xu38320c72008-01-28 19:35:05 -080044 if (len) {
45 len += crypto_aead_alignmask(aead) &
46 ~(crypto_tfm_ctx_alignment() - 1);
47 len = ALIGN(len, crypto_tfm_ctx_alignment());
48 }
49
50 len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
51 len = ALIGN(len, __alignof__(struct scatterlist));
52
53 len += sizeof(struct scatterlist) * nfrags;
54
55 return kmalloc(len, GFP_ATOMIC);
56}
57
Steffen Klassert0dc49e92011-03-08 00:07:14 +000058static inline __be32 *esp_tmp_seqhi(void *tmp)
59{
60 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
61}
62static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
Herbert Xu38320c72008-01-28 19:35:05 -080063{
64 return crypto_aead_ivsize(aead) ?
Steffen Klassert0dc49e92011-03-08 00:07:14 +000065 PTR_ALIGN((u8 *)tmp + seqhilen,
66 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
Herbert Xu38320c72008-01-28 19:35:05 -080067}
68
69static inline struct aead_givcrypt_request *esp_tmp_givreq(
70 struct crypto_aead *aead, u8 *iv)
71{
72 struct aead_givcrypt_request *req;
73
74 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
75 crypto_tfm_ctx_alignment());
76 aead_givcrypt_set_tfm(req, aead);
77 return req;
78}
79
80static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
81{
82 struct aead_request *req;
83
84 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
85 crypto_tfm_ctx_alignment());
86 aead_request_set_tfm(req, aead);
87 return req;
88}
89
90static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
91 struct aead_request *req)
92{
93 return (void *)ALIGN((unsigned long)(req + 1) +
94 crypto_aead_reqsize(aead),
95 __alignof__(struct scatterlist));
96}
97
98static inline struct scatterlist *esp_givreq_sg(
99 struct crypto_aead *aead, struct aead_givcrypt_request *req)
100{
101 return (void *)ALIGN((unsigned long)(req + 1) +
102 crypto_aead_reqsize(aead),
103 __alignof__(struct scatterlist));
104}
105
106static void esp_output_done(struct crypto_async_request *base, int err)
107{
108 struct sk_buff *skb = base->data;
109
110 kfree(ESP_SKB_CB(skb)->tmp);
111 xfrm_output_resume(skb, err);
112}
113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
115{
116 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 struct ip_esp_hdr *esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800118 struct crypto_aead *aead;
119 struct aead_givcrypt_request *req;
120 struct scatterlist *sg;
121 struct scatterlist *asg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 struct esp_data *esp;
123 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800124 void *tmp;
125 u8 *iv;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700126 u8 *tail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 int blksize;
128 int clen;
129 int alen;
Martin Willid979e202010-12-08 04:37:50 +0000130 int plen;
131 int tfclen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000133 int assoclen;
134 int sglists;
135 int seqhilen;
136 __be32 *seqhi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137
Herbert Xu7b277b12007-10-10 15:44:06 -0700138 /* skb is pure payload to encrypt */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140 err = -ENOMEM;
141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800143 aead = esp->aead;
144 alen = crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145
Martin Willid979e202010-12-08 04:37:50 +0000146 tfclen = 0;
147 if (x->tfcpad) {
148 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
149 u32 padto;
150
151 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
152 if (skb->len < padto)
153 tfclen = padto - skb->len;
154 }
Herbert Xu38320c72008-01-28 19:35:05 -0800155 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willid979e202010-12-08 04:37:50 +0000156 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Herbert Xu38320c72008-01-28 19:35:05 -0800157 if (esp->padlen)
158 clen = ALIGN(clen, esp->padlen);
Martin Willid979e202010-12-08 04:37:50 +0000159 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800160
Martin Willid979e202010-12-08 04:37:50 +0000161 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
162 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800164 nfrags = err;
165
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000166 assoclen = sizeof(*esph);
167 sglists = 1;
168 seqhilen = 0;
169
170 if (x->props.flags & XFRM_STATE_ESN) {
171 sglists += 2;
172 seqhilen += sizeof(__be32);
173 assoclen += seqhilen;
174 }
175
176 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800177 if (!tmp)
178 goto error;
179
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000180 seqhi = esp_tmp_seqhi(tmp);
181 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800182 req = esp_tmp_givreq(aead, iv);
183 asg = esp_givreq_sg(aead, req);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000184 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185
186 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700187 tail = skb_tail_pointer(trailer);
Martin Willid979e202010-12-08 04:37:50 +0000188 if (tfclen) {
189 memset(tail, 0, tfclen);
190 tail += tfclen;
191 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 do {
193 int i;
Martin Willid979e202010-12-08 04:37:50 +0000194 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700195 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 } while (0);
Martin Willid979e202010-12-08 04:37:50 +0000197 tail[plen - 2] = plen - 2;
198 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800199 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
Herbert Xu7b277b12007-10-10 15:44:06 -0700201 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700202 esph = ip_esp_hdr(skb);
Herbert Xu37fedd32007-10-10 15:44:44 -0700203 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204
205 /* this is non-NULL only with UDP Encapsulation */
206 if (x->encap) {
207 struct xfrm_encap_tmpl *encap = x->encap;
208 struct udphdr *uh;
Al Virod5a0a1e2006-11-08 00:23:14 -0800209 __be32 *udpdata32;
Al Viro5e226e42008-03-17 22:50:23 -0700210 __be16 sport, dport;
Herbert Xu38320c72008-01-28 19:35:05 -0800211 int encap_type;
212
213 spin_lock_bh(&x->lock);
214 sport = encap->encap_sport;
215 dport = encap->encap_dport;
216 encap_type = encap->encap_type;
217 spin_unlock_bh(&x->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
219 uh = (struct udphdr *)esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800220 uh->source = sport;
221 uh->dest = dport;
222 uh->len = htons(skb->len - skb_transport_offset(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 uh->check = 0;
224
Herbert Xu38320c72008-01-28 19:35:05 -0800225 switch (encap_type) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 default:
227 case UDP_ENCAP_ESPINUDP:
228 esph = (struct ip_esp_hdr *)(uh + 1);
229 break;
230 case UDP_ENCAP_ESPINUDP_NON_IKE:
Al Virod5a0a1e2006-11-08 00:23:14 -0800231 udpdata32 = (__be32 *)(uh + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 udpdata32[0] = udpdata32[1] = 0;
233 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
234 break;
235 }
236
Herbert Xu37fedd32007-10-10 15:44:44 -0700237 *skb_mac_header(skb) = IPPROTO_UDP;
238 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240 esph->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000241 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
Herbert Xu38320c72008-01-28 19:35:05 -0800243 sg_init_table(sg, nfrags);
244 skb_to_sgvec(skb, sg,
245 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
246 clen + alen);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000247
248 if ((x->props.flags & XFRM_STATE_ESN)) {
249 sg_init_table(asg, 3);
250 sg_set_buf(asg, &esph->spi, sizeof(__be32));
251 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
252 sg_set_buf(asg + 1, seqhi, seqhilen);
253 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
254 } else
255 sg_init_one(asg, esph, sizeof(*esph));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
Herbert Xu38320c72008-01-28 19:35:05 -0800257 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
258 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000259 aead_givcrypt_set_assoc(req, asg, assoclen);
Herbert Xub318e0e2008-02-12 22:50:35 -0800260 aead_givcrypt_set_giv(req, esph->enc_data,
Steffen Klassert1ce36442011-03-08 00:06:31 +0000261 XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
Herbert Xu38320c72008-01-28 19:35:05 -0800263 ESP_SKB_CB(skb)->tmp = tmp;
264 err = crypto_aead_givencrypt(req);
265 if (err == -EINPROGRESS)
266 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
Herbert Xu38320c72008-01-28 19:35:05 -0800268 if (err == -EBUSY)
269 err = NET_XMIT_DROP;
Herbert Xu6b7326c2006-07-30 15:41:01 +1000270
Herbert Xu38320c72008-01-28 19:35:05 -0800271 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700272
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273error:
274 return err;
275}
276
Herbert Xu38320c72008-01-28 19:35:05 -0800277static int esp_input_done2(struct sk_buff *skb, int err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278{
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000279 const struct iphdr *iph;
Herbert Xu38320c72008-01-28 19:35:05 -0800280 struct xfrm_state *x = xfrm_input_state(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800282 struct crypto_aead *aead = esp->aead;
283 int alen = crypto_aead_authsize(aead);
284 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
285 int elen = skb->len - hlen;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700286 int ihl;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800287 u8 nexthdr[2];
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800288 int padlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
Herbert Xu38320c72008-01-28 19:35:05 -0800290 kfree(ESP_SKB_CB(skb)->tmp);
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800291
Herbert Xu6b7326c2006-07-30 15:41:01 +1000292 if (unlikely(err))
Herbert Xu668dc8a2007-12-16 15:55:02 -0800293 goto out;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800294
295 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
296 BUG();
297
Herbert Xu668dc8a2007-12-16 15:55:02 -0800298 err = -EINVAL;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800299 padlen = nexthdr[0];
Herbert Xu38320c72008-01-28 19:35:05 -0800300 if (padlen + 2 + alen >= elen)
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800301 goto out;
302
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900303 /* ... check padding bits here. Silly. :-) */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800304
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700305 iph = ip_hdr(skb);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700306 ihl = iph->ihl * 4;
307
Herbert Xu752c1f42006-02-27 13:00:40 -0800308 if (x->encap) {
309 struct xfrm_encap_tmpl *encap = x->encap;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700310 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
Herbert Xu752c1f42006-02-27 13:00:40 -0800311
312 /*
313 * 1) if the NAT-T peer's IP or port changed then
314 * advertize the change to the keying daemon.
315 * This is an inbound SA, so just compare
316 * SRC ports.
317 */
318 if (iph->saddr != x->props.saddr.a4 ||
319 uh->source != encap->encap_sport) {
320 xfrm_address_t ipaddr;
321
322 ipaddr.a4 = iph->saddr;
323 km_new_mapping(x, &ipaddr, uh->source);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900324
Herbert Xu752c1f42006-02-27 13:00:40 -0800325 /* XXX: perhaps add an extra
326 * policy check here, to see
327 * if we should allow or
328 * reject a packet from a
329 * different source
330 * address/port.
331 */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800332 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900333
Herbert Xu752c1f42006-02-27 13:00:40 -0800334 /*
335 * 2) ignore UDP/TCP checksums in case
336 * of NAT-T in Transport Mode, or
337 * perform other post-processing fixes
338 * as per draft-ietf-ipsec-udp-encaps-06,
339 * section 3.1.2
340 */
Herbert Xu8bd17072007-10-10 15:41:41 -0700341 if (x->props.mode == XFRM_MODE_TRANSPORT)
Herbert Xu752c1f42006-02-27 13:00:40 -0800342 skb->ip_summed = CHECKSUM_UNNECESSARY;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800343 }
344
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800345 pskb_trim(skb, skb->len - alen - padlen - 2);
Herbert Xu38320c72008-01-28 19:35:05 -0800346 __skb_pull(skb, hlen);
Arnaldo Carvalho de Melo967b05f2007-03-13 13:51:52 -0300347 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;
374 struct esp_data *esp = x->data;
375 struct crypto_aead *aead = esp->aead;
376 struct aead_request *req;
377 struct sk_buff *trailer;
378 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
379 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000380 int assoclen;
381 int sglists;
382 int seqhilen;
383 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800384 void *tmp;
385 u8 *iv;
386 struct scatterlist *sg;
387 struct scatterlist *asg;
388 int err = -EINVAL;
389
Thomas Graf920fc942008-03-27 16:08:03 -0700390 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
Herbert Xu38320c72008-01-28 19:35:05 -0800391 goto out;
392
393 if (elen <= 0)
394 goto out;
395
396 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
397 goto out;
398 nfrags = err;
399
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000400 assoclen = sizeof(*esph);
401 sglists = 1;
402 seqhilen = 0;
403
404 if (x->props.flags & XFRM_STATE_ESN) {
405 sglists += 2;
406 seqhilen += sizeof(__be32);
407 assoclen += seqhilen;
408 }
409
Herbert Xu38320c72008-01-28 19:35:05 -0800410 err = -ENOMEM;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000411 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800412 if (!tmp)
413 goto out;
414
415 ESP_SKB_CB(skb)->tmp = tmp;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000416 seqhi = esp_tmp_seqhi(tmp);
417 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800418 req = esp_tmp_req(aead, iv);
419 asg = esp_req_sg(aead, req);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000420 sg = asg + sglists;
Herbert Xu38320c72008-01-28 19:35:05 -0800421
422 skb->ip_summed = CHECKSUM_NONE;
423
424 esph = (struct ip_esp_hdr *)skb->data;
425
426 /* Get ivec. This can be wrong, check against another impls. */
427 iv = esph->enc_data;
428
429 sg_init_table(sg, nfrags);
430 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000431
432 if ((x->props.flags & XFRM_STATE_ESN)) {
433 sg_init_table(asg, 3);
434 sg_set_buf(asg, &esph->spi, sizeof(__be32));
435 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
436 sg_set_buf(asg + 1, seqhi, seqhilen);
437 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
438 } else
439 sg_init_one(asg, esph, sizeof(*esph));
Herbert Xu38320c72008-01-28 19:35:05 -0800440
441 aead_request_set_callback(req, 0, esp_input_done, skb);
442 aead_request_set_crypt(req, sg, sg, elen, iv);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000443 aead_request_set_assoc(req, asg, assoclen);
Herbert Xu38320c72008-01-28 19:35:05 -0800444
445 err = crypto_aead_decrypt(req);
446 if (err == -EINPROGRESS)
447 goto out;
448
449 err = esp_input_done2(skb, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450
451out:
Herbert Xu668dc8a2007-12-16 15:55:02 -0800452 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453}
454
Patrick McHardyc5c25232007-04-09 11:47:18 -0700455static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456{
457 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800458 u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
459 u32 align = max_t(u32, blksize, esp->padlen);
Patrick McHardyc5c25232007-04-09 11:47:18 -0700460 u32 rem;
461
Herbert Xu38320c72008-01-28 19:35:05 -0800462 mtu -= x->props.header_len + crypto_aead_authsize(esp->aead);
Patrick McHardyc5c25232007-04-09 11:47:18 -0700463 rem = mtu & (align - 1);
464 mtu &= ~(align - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
Diego Beltrami0a694522006-10-03 23:47:05 -0700466 switch (x->props.mode) {
467 case XFRM_MODE_TUNNEL:
Diego Beltrami0a694522006-10-03 23:47:05 -0700468 break;
469 default:
470 case XFRM_MODE_TRANSPORT:
471 /* The worst case */
Patrick McHardyc5c25232007-04-09 11:47:18 -0700472 mtu -= blksize - 4;
473 mtu += min_t(u32, blksize - 4, rem);
Diego Beltrami0a694522006-10-03 23:47:05 -0700474 break;
475 case XFRM_MODE_BEET:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900476 /* The worst case. */
Patrick McHardyc5c25232007-04-09 11:47:18 -0700477 mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem);
Diego Beltrami0a694522006-10-03 23:47:05 -0700478 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 }
Diego Beltrami0a694522006-10-03 23:47:05 -0700480
Patrick McHardyc5c25232007-04-09 11:47:18 -0700481 return mtu - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482}
483
484static void esp4_err(struct sk_buff *skb, u32 info)
485{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800486 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000487 const struct iphdr *iph = (const struct iphdr *)skb->data;
Jianjun Kongd9319102008-11-03 00:23:42 -0800488 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 struct xfrm_state *x;
490
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300491 if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
492 icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 return;
494
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000495 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
496 esph->spi, IPPROTO_ESP, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 if (!x)
498 return;
Patrick McHardy64ce2072005-08-09 20:50:53 -0700499 NETDEBUG(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
500 ntohl(esph->spi), ntohl(iph->daddr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 xfrm_state_put(x);
502}
503
504static void esp_destroy(struct xfrm_state *x)
505{
506 struct esp_data *esp = x->data;
507
508 if (!esp)
509 return;
510
Herbert Xu38320c72008-01-28 19:35:05 -0800511 crypto_free_aead(esp->aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 kfree(esp);
513}
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 esp_data *esp = x->data;
518 struct crypto_aead *aead;
519 int err;
520
521 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
522 err = PTR_ERR(aead);
523 if (IS_ERR(aead))
524 goto error;
525
526 esp->aead = aead;
527
528 err = crypto_aead_setkey(aead, x->aead->alg_key,
529 (x->aead->alg_key_len + 7) / 8);
530 if (err)
531 goto error;
532
533 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
534 if (err)
535 goto error;
536
537error:
538 return err;
539}
540
541static int esp_init_authenc(struct xfrm_state *x)
542{
543 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800544 struct crypto_aead *aead;
545 struct crypto_authenc_key_param *param;
546 struct rtattr *rta;
547 char *key;
548 char *p;
549 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800550 unsigned int keylen;
551 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552
Herbert Xu1a6509d2008-01-28 19:37:29 -0800553 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 if (x->ealg == NULL)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800555 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800556
Herbert Xu1a6509d2008-01-28 19:37:29 -0800557 err = -ENAMETOOLONG;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000558
559 if ((x->props.flags & XFRM_STATE_ESN)) {
560 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
561 "authencesn(%s,%s)",
562 x->aalg ? x->aalg->alg_name : "digest_null",
563 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
564 goto error;
565 } else {
566 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
567 "authenc(%s,%s)",
568 x->aalg ? x->aalg->alg_name : "digest_null",
569 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
570 goto error;
571 }
Herbert Xu38320c72008-01-28 19:35:05 -0800572
573 aead = crypto_alloc_aead(authenc_name, 0, 0);
574 err = PTR_ERR(aead);
575 if (IS_ERR(aead))
576 goto error;
577
578 esp->aead = aead;
579
580 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
581 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
582 err = -ENOMEM;
583 key = kmalloc(keylen, GFP_KERNEL);
584 if (!key)
585 goto error;
586
587 p = key;
588 rta = (void *)p;
589 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
590 rta->rta_len = RTA_LENGTH(sizeof(*param));
591 param = RTA_DATA(rta);
592 p += RTA_SPACE(sizeof(*param));
593
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 if (x->aalg) {
595 struct xfrm_algo_desc *aalg_desc;
596
Herbert Xu38320c72008-01-28 19:35:05 -0800597 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
598 p += (x->aalg->alg_key_len + 7) / 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599
600 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
601 BUG_ON(!aalg_desc);
602
Herbert Xu38320c72008-01-28 19:35:05 -0800603 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800605 crypto_aead_authsize(aead)) {
Patrick McHardy64ce2072005-08-09 20:50:53 -0700606 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
607 x->aalg->alg_name,
Herbert Xu38320c72008-01-28 19:35:05 -0800608 crypto_aead_authsize(aead),
Patrick McHardy64ce2072005-08-09 20:50:53 -0700609 aalg_desc->uinfo.auth.icv_fullbits/8);
Herbert Xu38320c72008-01-28 19:35:05 -0800610 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 }
612
Herbert Xu38320c72008-01-28 19:35:05 -0800613 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000614 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800615 if (err)
616 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 }
Herbert Xu4b7137f2007-10-08 17:13:44 -0700618
Herbert Xu38320c72008-01-28 19:35:05 -0800619 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
620 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
621
622 err = crypto_aead_setkey(aead, key, keylen);
623
624free_key:
625 kfree(key);
626
Herbert Xu1a6509d2008-01-28 19:37:29 -0800627error:
628 return err;
629}
630
631static int esp_init_state(struct xfrm_state *x)
632{
633 struct esp_data *esp;
634 struct crypto_aead *aead;
635 u32 align;
636 int err;
637
638 esp = kzalloc(sizeof(*esp), GFP_KERNEL);
639 if (esp == NULL)
640 return -ENOMEM;
641
642 x->data = esp;
643
644 if (x->aead)
645 err = esp_init_aead(x);
646 else
647 err = esp_init_authenc(x);
648
Herbert Xu38320c72008-01-28 19:35:05 -0800649 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800651
Herbert Xu1a6509d2008-01-28 19:37:29 -0800652 aead = esp->aead;
653
654 esp->padlen = 0;
655
Herbert Xu38320c72008-01-28 19:35:05 -0800656 x->props.header_len = sizeof(struct ip_esp_hdr) +
657 crypto_aead_ivsize(aead);
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700658 if (x->props.mode == XFRM_MODE_TUNNEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 x->props.header_len += sizeof(struct iphdr);
Joakim Koskelaeb49e632008-08-06 02:39:30 -0700660 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
Patrick McHardyac758e32007-04-09 11:47:58 -0700661 x->props.header_len += IPV4_BEET_PHMAXLEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 if (x->encap) {
663 struct xfrm_encap_tmpl *encap = x->encap;
664
665 switch (encap->encap_type) {
666 default:
667 goto error;
668 case UDP_ENCAP_ESPINUDP:
669 x->props.header_len += sizeof(struct udphdr);
670 break;
671 case UDP_ENCAP_ESPINUDP_NON_IKE:
672 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
673 break;
674 }
675 }
Herbert Xu38320c72008-01-28 19:35:05 -0800676
677 align = ALIGN(crypto_aead_blocksize(aead), 4);
678 if (esp->padlen)
679 align = max_t(u32, align, esp->padlen);
680 x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681
682error:
Herbert Xu38320c72008-01-28 19:35:05 -0800683 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684}
685
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800686static const struct xfrm_type esp_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687{
688 .description = "ESP4",
689 .owner = THIS_MODULE,
690 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700691 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 .init_state = esp_init_state,
693 .destructor = esp_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700694 .get_mtu = esp4_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 .input = esp_input,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 .output = esp_output
697};
698
Alexey Dobriyan32613092009-09-14 12:21:47 +0000699static const struct net_protocol esp4_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 .handler = xfrm4_rcv,
701 .err_handler = esp4_err,
702 .no_policy = 1,
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800703 .netns_ok = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704};
705
706static int __init esp4_init(void)
707{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
709 printk(KERN_INFO "ip esp init: can't add xfrm type\n");
710 return -EAGAIN;
711 }
712 if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
713 printk(KERN_INFO "ip esp init: can't add protocol\n");
714 xfrm_unregister_type(&esp_type, AF_INET);
715 return -EAGAIN;
716 }
717 return 0;
718}
719
720static void __exit esp4_fini(void)
721{
722 if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
723 printk(KERN_INFO "ip esp close: can't remove protocol\n");
724 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
725 printk(KERN_INFO "ip esp close: can't remove xfrm type\n");
726}
727
728module_init(esp4_init);
729module_exit(esp4_fini);
730MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700731MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);