blob: a2afa89513a06d43ecdac6033dfcf89c16ea8ffc [file] [log] [blame]
Joe Perchesafd465032012-03-12 07:03:32 +00001#define pr_fmt(fmt) "IPsec: " fmt
2
Steffen Klassertdff3bb02009-10-07 22:48:17 +00003#include <crypto/hash.h>
Herbert Xu07d4ee52006-08-20 14:24:50 +10004#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09006#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <net/ip.h>
8#include <net/xfrm.h>
9#include <net/ah.h>
10#include <linux/crypto.h>
11#include <linux/pfkeyv2.h>
Steffen Klassertdff3bb02009-10-07 22:48:17 +000012#include <linux/scatterlist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <net/icmp.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020014#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
Steffen Klassertdff3bb02009-10-07 22:48:17 +000016struct ah_skb_cb {
17 struct xfrm_skb_cb xfrm;
18 void *tmp;
19};
20
21#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
22
23static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
24 unsigned int size)
25{
26 unsigned int len;
27
28 len = size + crypto_ahash_digestsize(ahash) +
29 (crypto_ahash_alignmask(ahash) &
30 ~(crypto_tfm_ctx_alignment() - 1));
31
32 len = ALIGN(len, crypto_tfm_ctx_alignment());
33
34 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
35 len = ALIGN(len, __alignof__(struct scatterlist));
36
37 len += sizeof(struct scatterlist) * nfrags;
38
39 return kmalloc(len, GFP_ATOMIC);
40}
41
42static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset)
43{
44 return tmp + offset;
45}
46
47static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
48 unsigned int offset)
49{
50 return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
51}
52
53static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
54 u8 *icv)
55{
56 struct ahash_request *req;
57
58 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
59 crypto_tfm_ctx_alignment());
60
61 ahash_request_set_tfm(req, ahash);
62
63 return req;
64}
65
66static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
67 struct ahash_request *req)
68{
69 return (void *)ALIGN((unsigned long)(req + 1) +
70 crypto_ahash_reqsize(ahash),
71 __alignof__(struct scatterlist));
72}
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74/* Clear mutable options and find final destination to substitute
75 * into IP header for icv calculation. Options are already checked
76 * for validity, so paranoia is not required. */
77
Eric Dumazetb71d1d42011-04-22 04:53:02 +000078static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079{
Daniel Baluta5e73ea12012-04-15 01:34:41 +000080 unsigned char *optptr = (unsigned char *)(iph+1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 int l = iph->ihl*4 - sizeof(struct iphdr);
82 int optlen;
83
84 while (l > 0) {
85 switch (*optptr) {
86 case IPOPT_END:
87 return 0;
88 case IPOPT_NOOP:
89 l--;
90 optptr++;
91 continue;
92 }
93 optlen = optptr[1];
94 if (optlen<2 || optlen>l)
95 return -EINVAL;
96 switch (*optptr) {
97 case IPOPT_SEC:
98 case 0x85: /* Some "Extended Security" crap. */
Paul Moore11a03f72006-08-03 16:46:20 -070099 case IPOPT_CIPSO:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 case IPOPT_RA:
101 case 0x80|21: /* RFC1770 */
102 break;
103 case IPOPT_LSRR:
104 case IPOPT_SSRR:
105 if (optlen < 6)
106 return -EINVAL;
107 memcpy(daddr, optptr+optlen-4, 4);
108 /* Fall through */
109 default:
Nick Bowler96fe1c02007-08-22 12:33:51 -0700110 memset(optptr, 0, optlen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 }
112 l -= optlen;
113 optptr += optlen;
114 }
115 return 0;
116}
117
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000118static void ah_output_done(struct crypto_async_request *base, int err)
119{
120 u8 *icv;
121 struct iphdr *iph;
122 struct sk_buff *skb = base->data;
123 struct xfrm_state *x = skb_dst(skb)->xfrm;
124 struct ah_data *ahp = x->data;
125 struct iphdr *top_iph = ip_hdr(skb);
126 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
127 int ihl = ip_hdrlen(skb);
128
129 iph = AH_SKB_CB(skb)->tmp;
130 icv = ah_tmp_icv(ahp->ahash, iph, ihl);
131 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
132
133 top_iph->tos = iph->tos;
134 top_iph->ttl = iph->ttl;
135 top_iph->frag_off = iph->frag_off;
136 if (top_iph->ihl != 5) {
137 top_iph->daddr = iph->daddr;
138 memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
139 }
140
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000141 kfree(AH_SKB_CB(skb)->tmp);
142 xfrm_output_resume(skb, err);
143}
144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
146{
147 int err;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000148 int nfrags;
149 int ihl;
150 u8 *icv;
151 struct sk_buff *trailer;
152 struct crypto_ahash *ahash;
153 struct ahash_request *req;
154 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 struct iphdr *iph, *top_iph;
156 struct ip_auth_hdr *ah;
157 struct ah_data *ahp;
Fan Dud4d573d2014-01-18 09:54:24 +0800158 int seqhi_len = 0;
159 __be32 *seqhi;
160 int sglists = 0;
161 struct scatterlist *seqhisg;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000162
163 ahp = x->data;
164 ahash = ahp->ahash;
165
166 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
167 goto out;
168 nfrags = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169
Herbert Xu7b277b12007-10-10 15:44:06 -0700170 skb_push(skb, -skb_network_offset(skb));
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000171 ah = ip_auth_hdr(skb);
172 ihl = ip_hdrlen(skb);
173
Fan Dud4d573d2014-01-18 09:54:24 +0800174 if (x->props.flags & XFRM_STATE_ESN) {
175 sglists = 1;
176 seqhi_len = sizeof(*seqhi);
177 }
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000178 err = -ENOMEM;
Fan Dud4d573d2014-01-18 09:54:24 +0800179 iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + seqhi_len);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000180 if (!iph)
181 goto out;
Fan Dud4d573d2014-01-18 09:54:24 +0800182 seqhi = (__be32 *)((char *)iph + ihl);
183 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000184 req = ah_tmp_req(ahash, icv);
185 sg = ah_req_sg(ahash, req);
Fan Dud4d573d2014-01-18 09:54:24 +0800186 seqhisg = sg + nfrags;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000187
188 memset(ah->auth_data, 0, ahp->icv_trunc_len);
189
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700190 top_iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
192 iph->tos = top_iph->tos;
193 iph->ttl = top_iph->ttl;
194 iph->frag_off = top_iph->frag_off;
195
196 if (top_iph->ihl != 5) {
197 iph->daddr = top_iph->daddr;
198 memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
199 err = ip_clear_mutable_options(top_iph, &top_iph->daddr);
200 if (err)
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000201 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
203
Herbert Xu37fedd32007-10-10 15:44:44 -0700204 ah->nexthdr = *skb_mac_header(skb);
205 *skb_mac_header(skb) = IPPROTO_AH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
207 top_iph->tos = 0;
208 top_iph->tot_len = htons(skb->len);
209 top_iph->frag_off = 0;
210 top_iph->ttl = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 top_iph->check = 0;
212
Nicolas Dichtelfa9921e2011-02-02 06:29:02 +0000213 if (x->props.flags & XFRM_STATE_ALIGN4)
214 ah->hdrlen = (XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
215 else
216 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
218 ah->reserved = 0;
219 ah->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000220 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Herbert Xub7c65382007-10-09 13:33:35 -0700221
Fan Dud4d573d2014-01-18 09:54:24 +0800222 sg_init_table(sg, nfrags + sglists);
223 skb_to_sgvec_nomark(skb, sg, 0, skb->len);
Herbert Xub7c65382007-10-09 13:33:35 -0700224
Fan Dud4d573d2014-01-18 09:54:24 +0800225 if (x->props.flags & XFRM_STATE_ESN) {
226 /* Attach seqhi sg right after packet payload */
227 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
228 sg_set_buf(seqhisg, seqhi, seqhi_len);
229 }
230 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000231 ahash_request_set_callback(req, 0, ah_output_done, skb);
232
233 AH_SKB_CB(skb)->tmp = iph;
234
235 err = crypto_ahash_digest(req);
236 if (err) {
237 if (err == -EINPROGRESS)
238 goto out;
239
240 if (err == -EBUSY)
241 err = NET_XMIT_DROP;
242 goto out_free;
243 }
244
245 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 top_iph->tos = iph->tos;
248 top_iph->ttl = iph->ttl;
249 top_iph->frag_off = iph->frag_off;
250 if (top_iph->ihl != 5) {
251 top_iph->daddr = iph->daddr;
252 memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
253 }
254
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000255out_free:
256 kfree(iph);
257out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 return err;
259}
260
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000261static void ah_input_done(struct crypto_async_request *base, int err)
262{
263 u8 *auth_data;
264 u8 *icv;
265 struct iphdr *work_iph;
266 struct sk_buff *skb = base->data;
267 struct xfrm_state *x = xfrm_input_state(skb);
268 struct ah_data *ahp = x->data;
269 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
270 int ihl = ip_hdrlen(skb);
271 int ah_hlen = (ah->hdrlen + 2) << 2;
272
273 work_iph = AH_SKB_CB(skb)->tmp;
274 auth_data = ah_tmp_auth(work_iph, ihl);
275 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
276
277 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
278 if (err)
279 goto out;
280
Nick Bowlerb7ea81a2011-11-08 12:12:45 +0000281 err = ah->nexthdr;
282
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000283 skb->network_header += ah_hlen;
284 memcpy(skb_network_header(skb), work_iph, ihl);
285 __skb_pull(skb, ah_hlen + ihl);
Li RongQing7143dfa2012-12-28 16:07:16 +0800286
287 if (x->props.mode == XFRM_MODE_TUNNEL)
288 skb_reset_transport_header(skb);
289 else
290 skb_set_transport_header(skb, -ihl);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000291out:
292 kfree(AH_SKB_CB(skb)->tmp);
293 xfrm_input_resume(skb, err);
294}
295
Herbert Xue6956332006-04-01 00:52:46 -0800296static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297{
298 int ah_hlen;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700299 int ihl;
Herbert Xu631a66982007-10-10 15:46:21 -0700300 int nexthdr;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000301 int nfrags;
302 u8 *auth_data;
303 u8 *icv;
304 struct sk_buff *trailer;
305 struct crypto_ahash *ahash;
306 struct ahash_request *req;
307 struct scatterlist *sg;
308 struct iphdr *iph, *work_iph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 struct ip_auth_hdr *ah;
310 struct ah_data *ahp;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000311 int err = -ENOMEM;
Fan Dud8b2a862014-01-18 09:54:25 +0800312 int seqhi_len = 0;
313 __be32 *seqhi;
314 int sglists = 0;
315 struct scatterlist *seqhisg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316
Herbert Xu87bdc482007-10-10 15:45:25 -0700317 if (!pskb_may_pull(skb, sizeof(*ah)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 goto out;
319
Herbert Xu87bdc482007-10-10 15:45:25 -0700320 ah = (struct ip_auth_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 ahp = x->data;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000322 ahash = ahp->ahash;
323
Herbert Xu631a66982007-10-10 15:46:21 -0700324 nexthdr = ah->nexthdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 ah_hlen = (ah->hdrlen + 2) << 2;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900326
Nicolas Dichtelfa9921e2011-02-02 06:29:02 +0000327 if (x->props.flags & XFRM_STATE_ALIGN4) {
328 if (ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_full_len) &&
329 ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len))
330 goto out;
331 } else {
332 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
333 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
334 goto out;
335 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
337 if (!pskb_may_pull(skb, ah_hlen))
338 goto out;
339
340 /* We are going to _remove_ AH header to keep sockets happy,
341 * so... Later this can change. */
Pravin B Shelar14bbd6a2013-02-14 09:44:49 +0000342 if (skb_unclone(skb, GFP_ATOMIC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 goto out;
344
345 skb->ip_summed = CHECKSUM_NONE;
346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000348 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
349 goto out;
350 nfrags = err;
351
Dang Hongwu4b0ef1f22011-01-11 07:13:33 +0000352 ah = (struct ip_auth_hdr *)skb->data;
353 iph = ip_hdr(skb);
354 ihl = ip_hdrlen(skb);
355
Fan Dud8b2a862014-01-18 09:54:25 +0800356 if (x->props.flags & XFRM_STATE_ESN) {
357 sglists = 1;
358 seqhi_len = sizeof(*seqhi);
359 }
360
361 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl +
362 ahp->icv_trunc_len + seqhi_len);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000363 if (!work_iph)
364 goto out;
365
Fan Dud8b2a862014-01-18 09:54:25 +0800366 seqhi = (__be32 *)((char *)work_iph + ihl);
367 auth_data = ah_tmp_auth(seqhi, seqhi_len);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000368 icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);
369 req = ah_tmp_req(ahash, icv);
370 sg = ah_req_sg(ahash, req);
Fan Dud8b2a862014-01-18 09:54:25 +0800371 seqhisg = sg + nfrags;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000372
373 memcpy(work_iph, iph, ihl);
374 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
375 memset(ah->auth_data, 0, ahp->icv_trunc_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
377 iph->ttl = 0;
378 iph->tos = 0;
379 iph->frag_off = 0;
380 iph->check = 0;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700381 if (ihl > sizeof(*iph)) {
Al Virod5a0a1e2006-11-08 00:23:14 -0800382 __be32 dummy;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000383 err = ip_clear_mutable_options(iph, &dummy);
Herbert Xu07d4ee52006-08-20 14:24:50 +1000384 if (err)
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000385 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 }
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800387
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000388 skb_push(skb, ihl);
389
Fan Dud8b2a862014-01-18 09:54:25 +0800390 sg_init_table(sg, nfrags + sglists);
391 skb_to_sgvec_nomark(skb, sg, 0, skb->len);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000392
Fan Dud8b2a862014-01-18 09:54:25 +0800393 if (x->props.flags & XFRM_STATE_ESN) {
394 /* Attach seqhi sg right after packet payload */
395 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
396 sg_set_buf(seqhisg, seqhi, seqhi_len);
397 }
398 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000399 ahash_request_set_callback(req, 0, ah_input_done, skb);
400
401 AH_SKB_CB(skb)->tmp = work_iph;
402
403 err = crypto_ahash_digest(req);
404 if (err) {
405 if (err == -EINPROGRESS)
406 goto out;
407
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000408 goto out_free;
409 }
410
411 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800412 if (err)
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000413 goto out_free;
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800414
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700415 skb->network_header += ah_hlen;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000416 memcpy(skb_network_header(skb), work_iph, ihl);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700417 __skb_pull(skb, ah_hlen + ihl);
Li RongQing7143dfa2012-12-28 16:07:16 +0800418 if (x->props.mode == XFRM_MODE_TUNNEL)
419 skb_reset_transport_header(skb);
420 else
421 skb_set_transport_header(skb, -ihl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000423 err = nexthdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000425out_free:
426 kfree (work_iph);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427out:
Herbert Xu07d4ee52006-08-20 14:24:50 +1000428 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429}
430
Steffen Klasserte5b56452014-02-21 08:41:09 +0100431static int ah4_err(struct sk_buff *skb, u32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800433 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000434 const struct iphdr *iph = (const struct iphdr *)skb->data;
Jianjun Kongd93191002008-11-03 00:23:42 -0800435 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 struct xfrm_state *x;
437
David S. Miller55be7a92012-07-11 21:27:49 -0700438 switch (icmp_hdr(skb)->type) {
439 case ICMP_DEST_UNREACH:
440 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
Steffen Klasserte5b56452014-02-21 08:41:09 +0100441 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -0700442 case ICMP_REDIRECT:
443 break;
444 default:
Steffen Klasserte5b56452014-02-21 08:41:09 +0100445 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -0700446 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000448 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
449 ah->spi, IPPROTO_AH, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 if (!x)
Steffen Klasserte5b56452014-02-21 08:41:09 +0100451 return 0;
David S. Miller55be7a92012-07-11 21:27:49 -0700452
Timo Teräs387aa652013-05-27 20:46:31 +0000453 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
David S. Miller55be7a92012-07-11 21:27:49 -0700454 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
Timo Teräs387aa652013-05-27 20:46:31 +0000455 else
David S. Miller55be7a92012-07-11 21:27:49 -0700456 ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 xfrm_state_put(x);
Steffen Klasserte5b56452014-02-21 08:41:09 +0100458
459 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460}
461
Herbert Xu72cb6962005-06-20 13:18:08 -0700462static int ah_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463{
464 struct ah_data *ahp = NULL;
465 struct xfrm_algo_desc *aalg_desc;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000466 struct crypto_ahash *ahash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
468 if (!x->aalg)
469 goto error;
470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 if (x->encap)
472 goto error;
473
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700474 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000475 if (!ahp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 return -ENOMEM;
477
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000478 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
479 if (IS_ERR(ahash))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 goto error;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000481
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000482 ahp->ahash = ahash;
483 if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
484 (x->aalg->alg_key_len + 7) / 8))
Herbert Xu07d4ee52006-08-20 14:24:50 +1000485 goto error;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900486
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 /*
488 * Lookup the algorithm description maintained by xfrm_algo,
489 * verify crypto transform properties, and store information
490 * we need for AH processing. This lookup cannot fail here
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000491 * after a successful crypto_alloc_ahash().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 */
493 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
494 BUG_ON(!aalg_desc);
495
496 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000497 crypto_ahash_digestsize(ahash)) {
Joe Perchesafd465032012-03-12 07:03:32 +0000498 pr_info("%s: %s digestsize %u != %hu\n",
499 __func__, x->aalg->alg_name,
500 crypto_ahash_digestsize(ahash),
501 aalg_desc->uinfo.auth.icv_fullbits / 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 goto error;
503 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900504
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
Martin Willi8f8a0882009-11-25 00:29:53 +0000506 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900507
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900509
Nicolas Dichtelfa9921e2011-02-02 06:29:02 +0000510 if (x->props.flags & XFRM_STATE_ALIGN4)
511 x->props.header_len = XFRM_ALIGN4(sizeof(struct ip_auth_hdr) +
512 ahp->icv_trunc_len);
513 else
514 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
515 ahp->icv_trunc_len);
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700516 if (x->props.mode == XFRM_MODE_TUNNEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 x->props.header_len += sizeof(struct iphdr);
518 x->data = ahp;
519
520 return 0;
521
522error:
523 if (ahp) {
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000524 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 kfree(ahp);
526 }
527 return -EINVAL;
528}
529
530static void ah_destroy(struct xfrm_state *x)
531{
532 struct ah_data *ahp = x->data;
533
534 if (!ahp)
535 return;
536
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000537 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 kfree(ahp);
539}
540
Steffen Klasserte5b56452014-02-21 08:41:09 +0100541static int ah4_rcv_cb(struct sk_buff *skb, int err)
542{
543 return 0;
544}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800546static const struct xfrm_type ah_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547{
548 .description = "AH4",
549 .owner = THIS_MODULE,
550 .proto = IPPROTO_AH,
Herbert Xu436a0a42007-10-08 17:25:53 -0700551 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 .init_state = ah_init_state,
553 .destructor = ah_destroy,
554 .input = ah_input,
555 .output = ah_output
556};
557
Steffen Klasserte5b56452014-02-21 08:41:09 +0100558static struct xfrm4_protocol ah4_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 .handler = xfrm4_rcv,
Steffen Klasserte5b56452014-02-21 08:41:09 +0100560 .input_handler = xfrm_input,
561 .cb_handler = ah4_rcv_cb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 .err_handler = ah4_err,
Steffen Klasserte5b56452014-02-21 08:41:09 +0100563 .priority = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564};
565
566static int __init ah4_init(void)
567{
568 if (xfrm_register_type(&ah_type, AF_INET) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000569 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 return -EAGAIN;
571 }
Steffen Klasserte5b56452014-02-21 08:41:09 +0100572 if (xfrm4_protocol_register(&ah4_protocol, IPPROTO_AH) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000573 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 xfrm_unregister_type(&ah_type, AF_INET);
575 return -EAGAIN;
576 }
577 return 0;
578}
579
580static void __exit ah4_fini(void)
581{
Steffen Klasserte5b56452014-02-21 08:41:09 +0100582 if (xfrm4_protocol_deregister(&ah4_protocol, IPPROTO_AH) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000583 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 if (xfrm_unregister_type(&ah_type, AF_INET) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000585 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586}
587
588module_init(ah4_init);
589module_exit(ah4_fini);
590MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700591MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH);