blob: 89a47b35905dcc6e1c3bb94b0db7c6a32a61e8fc [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 esp_data *esp;
125 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800126 void *tmp;
127 u8 *iv;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700128 u8 *tail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 int blksize;
130 int clen;
131 int alen;
Martin Willid979e202010-12-08 04:37:50 +0000132 int plen;
133 int tfclen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000135 int assoclen;
136 int sglists;
137 int seqhilen;
138 __be32 *seqhi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
Herbert Xu7b277b12007-10-10 15:44:06 -0700140 /* skb is pure payload to encrypt */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142 err = -ENOMEM;
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800145 aead = esp->aead;
146 alen = crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Martin Willid979e202010-12-08 04:37:50 +0000148 tfclen = 0;
149 if (x->tfcpad) {
150 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
151 u32 padto;
152
153 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
154 if (skb->len < padto)
155 tfclen = padto - skb->len;
156 }
Herbert Xu38320c72008-01-28 19:35:05 -0800157 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willid979e202010-12-08 04:37:50 +0000158 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Herbert Xu38320c72008-01-28 19:35:05 -0800159 if (esp->padlen)
160 clen = ALIGN(clen, esp->padlen);
Martin Willid979e202010-12-08 04:37:50 +0000161 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800162
Martin Willid979e202010-12-08 04:37:50 +0000163 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
164 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800166 nfrags = err;
167
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000168 assoclen = sizeof(*esph);
169 sglists = 1;
170 seqhilen = 0;
171
172 if (x->props.flags & XFRM_STATE_ESN) {
173 sglists += 2;
174 seqhilen += sizeof(__be32);
175 assoclen += seqhilen;
176 }
177
178 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800179 if (!tmp)
180 goto error;
181
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000182 seqhi = esp_tmp_seqhi(tmp);
183 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800184 req = esp_tmp_givreq(aead, iv);
185 asg = esp_givreq_sg(aead, req);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000186 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700189 tail = skb_tail_pointer(trailer);
Martin Willid979e202010-12-08 04:37:50 +0000190 if (tfclen) {
191 memset(tail, 0, tfclen);
192 tail += tfclen;
193 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 do {
195 int i;
Martin Willid979e202010-12-08 04:37:50 +0000196 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700197 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 } while (0);
Martin Willid979e202010-12-08 04:37:50 +0000199 tail[plen - 2] = plen - 2;
200 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800201 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
Herbert Xu7b277b12007-10-10 15:44:06 -0700203 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700204 esph = ip_esp_hdr(skb);
Herbert Xu37fedd32007-10-10 15:44:44 -0700205 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
207 /* this is non-NULL only with UDP Encapsulation */
208 if (x->encap) {
209 struct xfrm_encap_tmpl *encap = x->encap;
210 struct udphdr *uh;
Al Virod5a0a1e2006-11-08 00:23:14 -0800211 __be32 *udpdata32;
Al Viro5e226e42008-03-17 22:50:23 -0700212 __be16 sport, dport;
Herbert Xu38320c72008-01-28 19:35:05 -0800213 int encap_type;
214
215 spin_lock_bh(&x->lock);
216 sport = encap->encap_sport;
217 dport = encap->encap_dport;
218 encap_type = encap->encap_type;
219 spin_unlock_bh(&x->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221 uh = (struct udphdr *)esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800222 uh->source = sport;
223 uh->dest = dport;
224 uh->len = htons(skb->len - skb_transport_offset(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 uh->check = 0;
226
Herbert Xu38320c72008-01-28 19:35:05 -0800227 switch (encap_type) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 default:
229 case UDP_ENCAP_ESPINUDP:
230 esph = (struct ip_esp_hdr *)(uh + 1);
231 break;
232 case UDP_ENCAP_ESPINUDP_NON_IKE:
Al Virod5a0a1e2006-11-08 00:23:14 -0800233 udpdata32 = (__be32 *)(uh + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 udpdata32[0] = udpdata32[1] = 0;
235 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
236 break;
237 }
238
Herbert Xu37fedd32007-10-10 15:44:44 -0700239 *skb_mac_header(skb) = IPPROTO_UDP;
240 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
242 esph->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000243 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
Herbert Xu38320c72008-01-28 19:35:05 -0800245 sg_init_table(sg, nfrags);
246 skb_to_sgvec(skb, sg,
247 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
248 clen + alen);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000249
250 if ((x->props.flags & XFRM_STATE_ESN)) {
251 sg_init_table(asg, 3);
252 sg_set_buf(asg, &esph->spi, sizeof(__be32));
253 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
254 sg_set_buf(asg + 1, seqhi, seqhilen);
255 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
256 } else
257 sg_init_one(asg, esph, sizeof(*esph));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
Herbert Xu38320c72008-01-28 19:35:05 -0800259 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
260 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000261 aead_givcrypt_set_assoc(req, asg, assoclen);
Herbert Xub318e0e2008-02-12 22:50:35 -0800262 aead_givcrypt_set_giv(req, esph->enc_data,
Steffen Klassert1ce36442011-03-08 00:06:31 +0000263 XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Herbert Xu38320c72008-01-28 19:35:05 -0800265 ESP_SKB_CB(skb)->tmp = tmp;
266 err = crypto_aead_givencrypt(req);
267 if (err == -EINPROGRESS)
268 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
Herbert Xu38320c72008-01-28 19:35:05 -0800270 if (err == -EBUSY)
271 err = NET_XMIT_DROP;
Herbert Xu6b7326c2006-07-30 15:41:01 +1000272
Herbert Xu38320c72008-01-28 19:35:05 -0800273 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700274
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275error:
276 return err;
277}
278
Herbert Xu38320c72008-01-28 19:35:05 -0800279static int esp_input_done2(struct sk_buff *skb, int err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280{
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000281 const struct iphdr *iph;
Herbert Xu38320c72008-01-28 19:35:05 -0800282 struct xfrm_state *x = xfrm_input_state(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800284 struct crypto_aead *aead = esp->aead;
285 int alen = crypto_aead_authsize(aead);
286 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
287 int elen = skb->len - hlen;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700288 int ihl;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800289 u8 nexthdr[2];
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800290 int padlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291
Herbert Xu38320c72008-01-28 19:35:05 -0800292 kfree(ESP_SKB_CB(skb)->tmp);
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800293
Herbert Xu6b7326c2006-07-30 15:41:01 +1000294 if (unlikely(err))
Herbert Xu668dc8a2007-12-16 15:55:02 -0800295 goto out;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800296
297 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
298 BUG();
299
Herbert Xu668dc8a2007-12-16 15:55:02 -0800300 err = -EINVAL;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800301 padlen = nexthdr[0];
Herbert Xu38320c72008-01-28 19:35:05 -0800302 if (padlen + 2 + alen >= elen)
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800303 goto out;
304
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900305 /* ... check padding bits here. Silly. :-) */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800306
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700307 iph = ip_hdr(skb);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700308 ihl = iph->ihl * 4;
309
Herbert Xu752c1f42006-02-27 13:00:40 -0800310 if (x->encap) {
311 struct xfrm_encap_tmpl *encap = x->encap;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700312 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
Herbert Xu752c1f42006-02-27 13:00:40 -0800313
314 /*
315 * 1) if the NAT-T peer's IP or port changed then
316 * advertize the change to the keying daemon.
317 * This is an inbound SA, so just compare
318 * SRC ports.
319 */
320 if (iph->saddr != x->props.saddr.a4 ||
321 uh->source != encap->encap_sport) {
322 xfrm_address_t ipaddr;
323
324 ipaddr.a4 = iph->saddr;
325 km_new_mapping(x, &ipaddr, uh->source);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900326
Herbert Xu752c1f42006-02-27 13:00:40 -0800327 /* XXX: perhaps add an extra
328 * policy check here, to see
329 * if we should allow or
330 * reject a packet from a
331 * different source
332 * address/port.
333 */
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800334 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900335
Herbert Xu752c1f42006-02-27 13:00:40 -0800336 /*
337 * 2) ignore UDP/TCP checksums in case
338 * of NAT-T in Transport Mode, or
339 * perform other post-processing fixes
340 * as per draft-ietf-ipsec-udp-encaps-06,
341 * section 3.1.2
342 */
Herbert Xu8bd17072007-10-10 15:41:41 -0700343 if (x->props.mode == XFRM_MODE_TRANSPORT)
Herbert Xu752c1f42006-02-27 13:00:40 -0800344 skb->ip_summed = CHECKSUM_UNNECESSARY;
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800345 }
346
Herbert Xu4bf05ec2006-02-27 13:00:01 -0800347 pskb_trim(skb, skb->len - alen - padlen - 2);
Herbert Xu38320c72008-01-28 19:35:05 -0800348 __skb_pull(skb, hlen);
Arnaldo Carvalho de Melo967b05f2007-03-13 13:51:52 -0300349 skb_set_transport_header(skb, -ihl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
Herbert Xu38320c72008-01-28 19:35:05 -0800351 err = nexthdr[1];
352
353 /* RFC4303: Drop dummy packets without any error */
354 if (err == IPPROTO_NONE)
355 err = -EINVAL;
356
357out:
358 return err;
359}
360
361static void esp_input_done(struct crypto_async_request *base, int err)
362{
363 struct sk_buff *skb = base->data;
364
365 xfrm_input_resume(skb, esp_input_done2(skb, err));
366}
367
368/*
369 * Note: detecting truncated vs. non-truncated authentication data is very
370 * expensive, so we only support truncated data, which is the recommended
371 * and common case.
372 */
373static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
374{
375 struct ip_esp_hdr *esph;
376 struct esp_data *esp = x->data;
377 struct crypto_aead *aead = esp->aead;
378 struct aead_request *req;
379 struct sk_buff *trailer;
380 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
381 int nfrags;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000382 int assoclen;
383 int sglists;
384 int seqhilen;
385 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800386 void *tmp;
387 u8 *iv;
388 struct scatterlist *sg;
389 struct scatterlist *asg;
390 int err = -EINVAL;
391
Thomas Graf920fc942008-03-27 16:08:03 -0700392 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
Herbert Xu38320c72008-01-28 19:35:05 -0800393 goto out;
394
395 if (elen <= 0)
396 goto out;
397
398 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
399 goto out;
400 nfrags = err;
401
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000402 assoclen = sizeof(*esph);
403 sglists = 1;
404 seqhilen = 0;
405
406 if (x->props.flags & XFRM_STATE_ESN) {
407 sglists += 2;
408 seqhilen += sizeof(__be32);
409 assoclen += seqhilen;
410 }
411
Herbert Xu38320c72008-01-28 19:35:05 -0800412 err = -ENOMEM;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000413 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800414 if (!tmp)
415 goto out;
416
417 ESP_SKB_CB(skb)->tmp = tmp;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000418 seqhi = esp_tmp_seqhi(tmp);
419 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800420 req = esp_tmp_req(aead, iv);
421 asg = esp_req_sg(aead, req);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000422 sg = asg + sglists;
Herbert Xu38320c72008-01-28 19:35:05 -0800423
424 skb->ip_summed = CHECKSUM_NONE;
425
426 esph = (struct ip_esp_hdr *)skb->data;
427
428 /* Get ivec. This can be wrong, check against another impls. */
429 iv = esph->enc_data;
430
431 sg_init_table(sg, nfrags);
432 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000433
434 if ((x->props.flags & XFRM_STATE_ESN)) {
435 sg_init_table(asg, 3);
436 sg_set_buf(asg, &esph->spi, sizeof(__be32));
437 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
438 sg_set_buf(asg + 1, seqhi, seqhilen);
439 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
440 } else
441 sg_init_one(asg, esph, sizeof(*esph));
Herbert Xu38320c72008-01-28 19:35:05 -0800442
443 aead_request_set_callback(req, 0, esp_input_done, skb);
444 aead_request_set_crypt(req, sg, sg, elen, iv);
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000445 aead_request_set_assoc(req, asg, assoclen);
Herbert Xu38320c72008-01-28 19:35:05 -0800446
447 err = crypto_aead_decrypt(req);
448 if (err == -EINPROGRESS)
449 goto out;
450
451 err = esp_input_done2(skb, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
453out:
Herbert Xu668dc8a2007-12-16 15:55:02 -0800454 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455}
456
Patrick McHardyc5c25232007-04-09 11:47:18 -0700457static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458{
459 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800460 u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
461 u32 align = max_t(u32, blksize, esp->padlen);
Patrick McHardyc5c25232007-04-09 11:47:18 -0700462 u32 rem;
463
Herbert Xu38320c72008-01-28 19:35:05 -0800464 mtu -= x->props.header_len + crypto_aead_authsize(esp->aead);
Patrick McHardyc5c25232007-04-09 11:47:18 -0700465 rem = mtu & (align - 1);
466 mtu &= ~(align - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
Diego Beltrami0a694522006-10-03 23:47:05 -0700468 switch (x->props.mode) {
469 case XFRM_MODE_TUNNEL:
Diego Beltrami0a694522006-10-03 23:47:05 -0700470 break;
471 default:
472 case XFRM_MODE_TRANSPORT:
473 /* The worst case */
Patrick McHardyc5c25232007-04-09 11:47:18 -0700474 mtu -= blksize - 4;
475 mtu += min_t(u32, blksize - 4, rem);
Diego Beltrami0a694522006-10-03 23:47:05 -0700476 break;
477 case XFRM_MODE_BEET:
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900478 /* The worst case. */
Patrick McHardyc5c25232007-04-09 11:47:18 -0700479 mtu += min_t(u32, IPV4_BEET_PHMAXLEN, rem);
Diego Beltrami0a694522006-10-03 23:47:05 -0700480 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 }
Diego Beltrami0a694522006-10-03 23:47:05 -0700482
Patrick McHardyc5c25232007-04-09 11:47:18 -0700483 return mtu - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484}
485
486static void esp4_err(struct sk_buff *skb, u32 info)
487{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800488 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000489 const struct iphdr *iph = (const struct iphdr *)skb->data;
Jianjun Kongd93191002008-11-03 00:23:42 -0800490 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 struct xfrm_state *x;
492
Arnaldo Carvalho de Melo88c76642007-03-13 14:43:18 -0300493 if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
494 icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 return;
496
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000497 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
498 esph->spi, IPPROTO_ESP, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 if (!x)
500 return;
Patrick McHardy64ce2072005-08-09 20:50:53 -0700501 NETDEBUG(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%08x\n",
502 ntohl(esph->spi), ntohl(iph->daddr));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 xfrm_state_put(x);
504}
505
506static void esp_destroy(struct xfrm_state *x)
507{
508 struct esp_data *esp = x->data;
509
510 if (!esp)
511 return;
512
Herbert Xu38320c72008-01-28 19:35:05 -0800513 crypto_free_aead(esp->aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 kfree(esp);
515}
516
Herbert Xu1a6509d2008-01-28 19:37:29 -0800517static int esp_init_aead(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800519 struct esp_data *esp = x->data;
520 struct crypto_aead *aead;
521 int err;
522
523 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
524 err = PTR_ERR(aead);
525 if (IS_ERR(aead))
526 goto error;
527
528 esp->aead = aead;
529
530 err = crypto_aead_setkey(aead, x->aead->alg_key,
531 (x->aead->alg_key_len + 7) / 8);
532 if (err)
533 goto error;
534
535 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
536 if (err)
537 goto error;
538
539error:
540 return err;
541}
542
543static int esp_init_authenc(struct xfrm_state *x)
544{
545 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800546 struct crypto_aead *aead;
547 struct crypto_authenc_key_param *param;
548 struct rtattr *rta;
549 char *key;
550 char *p;
551 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800552 unsigned int keylen;
553 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
Herbert Xu1a6509d2008-01-28 19:37:29 -0800555 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 if (x->ealg == NULL)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800557 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800558
Herbert Xu1a6509d2008-01-28 19:37:29 -0800559 err = -ENAMETOOLONG;
Steffen Klassert0dc49e92011-03-08 00:07:14 +0000560
561 if ((x->props.flags & XFRM_STATE_ESN)) {
562 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
563 "authencesn(%s,%s)",
564 x->aalg ? x->aalg->alg_name : "digest_null",
565 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
566 goto error;
567 } else {
568 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
569 "authenc(%s,%s)",
570 x->aalg ? x->aalg->alg_name : "digest_null",
571 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
572 goto error;
573 }
Herbert Xu38320c72008-01-28 19:35:05 -0800574
575 aead = crypto_alloc_aead(authenc_name, 0, 0);
576 err = PTR_ERR(aead);
577 if (IS_ERR(aead))
578 goto error;
579
580 esp->aead = aead;
581
582 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
583 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
584 err = -ENOMEM;
585 key = kmalloc(keylen, GFP_KERNEL);
586 if (!key)
587 goto error;
588
589 p = key;
590 rta = (void *)p;
591 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
592 rta->rta_len = RTA_LENGTH(sizeof(*param));
593 param = RTA_DATA(rta);
594 p += RTA_SPACE(sizeof(*param));
595
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 if (x->aalg) {
597 struct xfrm_algo_desc *aalg_desc;
598
Herbert Xu38320c72008-01-28 19:35:05 -0800599 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
600 p += (x->aalg->alg_key_len + 7) / 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601
602 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
603 BUG_ON(!aalg_desc);
604
Herbert Xu38320c72008-01-28 19:35:05 -0800605 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800607 crypto_aead_authsize(aead)) {
Patrick McHardy64ce2072005-08-09 20:50:53 -0700608 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
609 x->aalg->alg_name,
Herbert Xu38320c72008-01-28 19:35:05 -0800610 crypto_aead_authsize(aead),
Patrick McHardy64ce2072005-08-09 20:50:53 -0700611 aalg_desc->uinfo.auth.icv_fullbits/8);
Herbert Xu38320c72008-01-28 19:35:05 -0800612 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 }
614
Herbert Xu38320c72008-01-28 19:35:05 -0800615 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000616 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800617 if (err)
618 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 }
Herbert Xu4b7137f2007-10-08 17:13:44 -0700620
Herbert Xu38320c72008-01-28 19:35:05 -0800621 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
622 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
623
624 err = crypto_aead_setkey(aead, key, keylen);
625
626free_key:
627 kfree(key);
628
Herbert Xu1a6509d2008-01-28 19:37:29 -0800629error:
630 return err;
631}
632
633static int esp_init_state(struct xfrm_state *x)
634{
635 struct esp_data *esp;
636 struct crypto_aead *aead;
637 u32 align;
638 int err;
639
640 esp = kzalloc(sizeof(*esp), GFP_KERNEL);
641 if (esp == NULL)
642 return -ENOMEM;
643
644 x->data = esp;
645
646 if (x->aead)
647 err = esp_init_aead(x);
648 else
649 err = esp_init_authenc(x);
650
Herbert Xu38320c72008-01-28 19:35:05 -0800651 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800653
Herbert Xu1a6509d2008-01-28 19:37:29 -0800654 aead = esp->aead;
655
656 esp->padlen = 0;
657
Herbert Xu38320c72008-01-28 19:35:05 -0800658 x->props.header_len = sizeof(struct ip_esp_hdr) +
659 crypto_aead_ivsize(aead);
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700660 if (x->props.mode == XFRM_MODE_TUNNEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 x->props.header_len += sizeof(struct iphdr);
Joakim Koskelaeb49e632008-08-06 02:39:30 -0700662 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
Patrick McHardyac758e32007-04-09 11:47:58 -0700663 x->props.header_len += IPV4_BEET_PHMAXLEN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 if (x->encap) {
665 struct xfrm_encap_tmpl *encap = x->encap;
666
667 switch (encap->encap_type) {
668 default:
669 goto error;
670 case UDP_ENCAP_ESPINUDP:
671 x->props.header_len += sizeof(struct udphdr);
672 break;
673 case UDP_ENCAP_ESPINUDP_NON_IKE:
674 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
675 break;
676 }
677 }
Herbert Xu38320c72008-01-28 19:35:05 -0800678
679 align = ALIGN(crypto_aead_blocksize(aead), 4);
680 if (esp->padlen)
681 align = max_t(u32, align, esp->padlen);
682 x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683
684error:
Herbert Xu38320c72008-01-28 19:35:05 -0800685 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686}
687
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800688static const struct xfrm_type esp_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689{
690 .description = "ESP4",
691 .owner = THIS_MODULE,
692 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700693 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 .init_state = esp_init_state,
695 .destructor = esp_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700696 .get_mtu = esp4_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 .input = esp_input,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 .output = esp_output
699};
700
Alexey Dobriyan32613092009-09-14 12:21:47 +0000701static const struct net_protocol esp4_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 .handler = xfrm4_rcv,
703 .err_handler = esp4_err,
704 .no_policy = 1,
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800705 .netns_ok = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706};
707
708static int __init esp4_init(void)
709{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000711 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 return -EAGAIN;
713 }
714 if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000715 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 xfrm_unregister_type(&esp_type, AF_INET);
717 return -EAGAIN;
718 }
719 return 0;
720}
721
722static void __exit esp4_fini(void)
723{
724 if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000725 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000727 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728}
729
730module_init(esp4_init);
731module_exit(esp4_fini);
732MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700733MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);