blob: 717902669d2f2ef34714c215c4695ffe59ddd283 [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;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000158
159 ahp = x->data;
160 ahash = ahp->ahash;
161
162 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
163 goto out;
164 nfrags = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
Herbert Xu7b277b12007-10-10 15:44:06 -0700166 skb_push(skb, -skb_network_offset(skb));
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000167 ah = ip_auth_hdr(skb);
168 ihl = ip_hdrlen(skb);
169
170 err = -ENOMEM;
171 iph = ah_alloc_tmp(ahash, nfrags, ihl);
172 if (!iph)
173 goto out;
174
175 icv = ah_tmp_icv(ahash, iph, ihl);
176 req = ah_tmp_req(ahash, icv);
177 sg = ah_req_sg(ahash, req);
178
179 memset(ah->auth_data, 0, ahp->icv_trunc_len);
180
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700181 top_iph = ip_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 iph->tos = top_iph->tos;
184 iph->ttl = top_iph->ttl;
185 iph->frag_off = top_iph->frag_off;
186
187 if (top_iph->ihl != 5) {
188 iph->daddr = top_iph->daddr;
189 memcpy(iph+1, top_iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
190 err = ip_clear_mutable_options(top_iph, &top_iph->daddr);
191 if (err)
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000192 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 }
194
Herbert Xu37fedd32007-10-10 15:44:44 -0700195 ah->nexthdr = *skb_mac_header(skb);
196 *skb_mac_header(skb) = IPPROTO_AH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
198 top_iph->tos = 0;
199 top_iph->tot_len = htons(skb->len);
200 top_iph->frag_off = 0;
201 top_iph->ttl = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 top_iph->check = 0;
203
Nicolas Dichtelfa9921e2011-02-02 06:29:02 +0000204 if (x->props.flags & XFRM_STATE_ALIGN4)
205 ah->hdrlen = (XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
206 else
207 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
209 ah->reserved = 0;
210 ah->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000211 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Herbert Xub7c65382007-10-09 13:33:35 -0700212
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000213 sg_init_table(sg, nfrags);
214 skb_to_sgvec(skb, sg, 0, skb->len);
Herbert Xub7c65382007-10-09 13:33:35 -0700215
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000216 ahash_request_set_crypt(req, sg, icv, skb->len);
217 ahash_request_set_callback(req, 0, ah_output_done, skb);
218
219 AH_SKB_CB(skb)->tmp = iph;
220
221 err = crypto_ahash_digest(req);
222 if (err) {
223 if (err == -EINPROGRESS)
224 goto out;
225
226 if (err == -EBUSY)
227 err = NET_XMIT_DROP;
228 goto out_free;
229 }
230
231 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
233 top_iph->tos = iph->tos;
234 top_iph->ttl = iph->ttl;
235 top_iph->frag_off = iph->frag_off;
236 if (top_iph->ihl != 5) {
237 top_iph->daddr = iph->daddr;
238 memcpy(top_iph+1, iph+1, top_iph->ihl*4 - sizeof(struct iphdr));
239 }
240
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000241out_free:
242 kfree(iph);
243out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 return err;
245}
246
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000247static void ah_input_done(struct crypto_async_request *base, int err)
248{
249 u8 *auth_data;
250 u8 *icv;
251 struct iphdr *work_iph;
252 struct sk_buff *skb = base->data;
253 struct xfrm_state *x = xfrm_input_state(skb);
254 struct ah_data *ahp = x->data;
255 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
256 int ihl = ip_hdrlen(skb);
257 int ah_hlen = (ah->hdrlen + 2) << 2;
258
259 work_iph = AH_SKB_CB(skb)->tmp;
260 auth_data = ah_tmp_auth(work_iph, ihl);
261 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
262
263 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
264 if (err)
265 goto out;
266
Nick Bowlerb7ea81a2011-11-08 12:12:45 +0000267 err = ah->nexthdr;
268
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000269 skb->network_header += ah_hlen;
270 memcpy(skb_network_header(skb), work_iph, ihl);
271 __skb_pull(skb, ah_hlen + ihl);
Li RongQing7143dfa2012-12-28 16:07:16 +0800272
273 if (x->props.mode == XFRM_MODE_TUNNEL)
274 skb_reset_transport_header(skb);
275 else
276 skb_set_transport_header(skb, -ihl);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000277out:
278 kfree(AH_SKB_CB(skb)->tmp);
279 xfrm_input_resume(skb, err);
280}
281
Herbert Xue6956332006-04-01 00:52:46 -0800282static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283{
284 int ah_hlen;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700285 int ihl;
Herbert Xu631a66982007-10-10 15:46:21 -0700286 int nexthdr;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000287 int nfrags;
288 u8 *auth_data;
289 u8 *icv;
290 struct sk_buff *trailer;
291 struct crypto_ahash *ahash;
292 struct ahash_request *req;
293 struct scatterlist *sg;
294 struct iphdr *iph, *work_iph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 struct ip_auth_hdr *ah;
296 struct ah_data *ahp;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000297 int err = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298
Herbert Xu87bdc482007-10-10 15:45:25 -0700299 if (!pskb_may_pull(skb, sizeof(*ah)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 goto out;
301
Herbert Xu87bdc482007-10-10 15:45:25 -0700302 ah = (struct ip_auth_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 ahp = x->data;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000304 ahash = ahp->ahash;
305
Herbert Xu631a66982007-10-10 15:46:21 -0700306 nexthdr = ah->nexthdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 ah_hlen = (ah->hdrlen + 2) << 2;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900308
Nicolas Dichtelfa9921e2011-02-02 06:29:02 +0000309 if (x->props.flags & XFRM_STATE_ALIGN4) {
310 if (ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_full_len) &&
311 ah_hlen != XFRM_ALIGN4(sizeof(*ah) + ahp->icv_trunc_len))
312 goto out;
313 } else {
314 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
315 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
316 goto out;
317 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
319 if (!pskb_may_pull(skb, ah_hlen))
320 goto out;
321
322 /* We are going to _remove_ AH header to keep sockets happy,
323 * so... Later this can change. */
Pravin B Shelar14bbd6a2013-02-14 09:44:49 +0000324 if (skb_unclone(skb, GFP_ATOMIC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 goto out;
326
327 skb->ip_summed = CHECKSUM_NONE;
328
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000330 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
331 goto out;
332 nfrags = err;
333
Dang Hongwu4b0ef1f22011-01-11 07:13:33 +0000334 ah = (struct ip_auth_hdr *)skb->data;
335 iph = ip_hdr(skb);
336 ihl = ip_hdrlen(skb);
337
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000338 work_iph = ah_alloc_tmp(ahash, nfrags, ihl + ahp->icv_trunc_len);
339 if (!work_iph)
340 goto out;
341
342 auth_data = ah_tmp_auth(work_iph, ihl);
343 icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);
344 req = ah_tmp_req(ahash, icv);
345 sg = ah_req_sg(ahash, req);
346
347 memcpy(work_iph, iph, ihl);
348 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
349 memset(ah->auth_data, 0, ahp->icv_trunc_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351 iph->ttl = 0;
352 iph->tos = 0;
353 iph->frag_off = 0;
354 iph->check = 0;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700355 if (ihl > sizeof(*iph)) {
Al Virod5a0a1e2006-11-08 00:23:14 -0800356 __be32 dummy;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000357 err = ip_clear_mutable_options(iph, &dummy);
Herbert Xu07d4ee52006-08-20 14:24:50 +1000358 if (err)
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000359 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 }
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800361
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000362 skb_push(skb, ihl);
363
364 sg_init_table(sg, nfrags);
365 skb_to_sgvec(skb, sg, 0, skb->len);
366
367 ahash_request_set_crypt(req, sg, icv, skb->len);
368 ahash_request_set_callback(req, 0, ah_input_done, skb);
369
370 AH_SKB_CB(skb)->tmp = work_iph;
371
372 err = crypto_ahash_digest(req);
373 if (err) {
374 if (err == -EINPROGRESS)
375 goto out;
376
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000377 goto out_free;
378 }
379
380 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800381 if (err)
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000382 goto out_free;
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800383
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700384 skb->network_header += ah_hlen;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000385 memcpy(skb_network_header(skb), work_iph, ihl);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700386 __skb_pull(skb, ah_hlen + ihl);
Li RongQing7143dfa2012-12-28 16:07:16 +0800387 if (x->props.mode == XFRM_MODE_TUNNEL)
388 skb_reset_transport_header(skb);
389 else
390 skb_set_transport_header(skb, -ihl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000392 err = nexthdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000394out_free:
395 kfree (work_iph);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396out:
Herbert Xu07d4ee52006-08-20 14:24:50 +1000397 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398}
399
400static void ah4_err(struct sk_buff *skb, u32 info)
401{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800402 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000403 const struct iphdr *iph = (const struct iphdr *)skb->data;
Jianjun Kongd93191002008-11-03 00:23:42 -0800404 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 struct xfrm_state *x;
406
David S. Miller55be7a92012-07-11 21:27:49 -0700407 switch (icmp_hdr(skb)->type) {
408 case ICMP_DEST_UNREACH:
409 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
410 return;
411 case ICMP_REDIRECT:
412 break;
413 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 return;
David S. Miller55be7a92012-07-11 21:27:49 -0700415 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000417 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
418 ah->spi, IPPROTO_AH, AF_INET);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 if (!x)
420 return;
David S. Miller55be7a92012-07-11 21:27:49 -0700421
Timo Teräs387aa652013-05-27 20:46:31 +0000422 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
David S. Miller55be7a92012-07-11 21:27:49 -0700423 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0);
Timo Teräs387aa652013-05-27 20:46:31 +0000424 else
David S. Miller55be7a92012-07-11 21:27:49 -0700425 ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 xfrm_state_put(x);
427}
428
Herbert Xu72cb6962005-06-20 13:18:08 -0700429static int ah_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430{
431 struct ah_data *ahp = NULL;
432 struct xfrm_algo_desc *aalg_desc;
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000433 struct crypto_ahash *ahash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
435 if (!x->aalg)
436 goto error;
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 if (x->encap)
439 goto error;
440
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700441 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000442 if (!ahp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 return -ENOMEM;
444
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000445 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
446 if (IS_ERR(ahash))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 goto error;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000448
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000449 ahp->ahash = ahash;
450 if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
451 (x->aalg->alg_key_len + 7) / 8))
Herbert Xu07d4ee52006-08-20 14:24:50 +1000452 goto error;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 /*
455 * Lookup the algorithm description maintained by xfrm_algo,
456 * verify crypto transform properties, and store information
457 * we need for AH processing. This lookup cannot fail here
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000458 * after a successful crypto_alloc_ahash().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 */
460 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
461 BUG_ON(!aalg_desc);
462
463 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000464 crypto_ahash_digestsize(ahash)) {
Joe Perchesafd465032012-03-12 07:03:32 +0000465 pr_info("%s: %s digestsize %u != %hu\n",
466 __func__, x->aalg->alg_name,
467 crypto_ahash_digestsize(ahash),
468 aalg_desc->uinfo.auth.icv_fullbits / 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 goto error;
470 }
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900471
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
Martin Willi8f8a0882009-11-25 00:29:53 +0000473 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900474
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +0900476
Nicolas Dichtelfa9921e2011-02-02 06:29:02 +0000477 if (x->props.flags & XFRM_STATE_ALIGN4)
478 x->props.header_len = XFRM_ALIGN4(sizeof(struct ip_auth_hdr) +
479 ahp->icv_trunc_len);
480 else
481 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
482 ahp->icv_trunc_len);
Masahide NAKAMURA7e49e6d2006-09-22 15:05:15 -0700483 if (x->props.mode == XFRM_MODE_TUNNEL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 x->props.header_len += sizeof(struct iphdr);
485 x->data = ahp;
486
487 return 0;
488
489error:
490 if (ahp) {
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000491 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 kfree(ahp);
493 }
494 return -EINVAL;
495}
496
497static void ah_destroy(struct xfrm_state *x)
498{
499 struct ah_data *ahp = x->data;
500
501 if (!ahp)
502 return;
503
Steffen Klassertdff3bb02009-10-07 22:48:17 +0000504 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 kfree(ahp);
506}
507
508
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800509static const struct xfrm_type ah_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510{
511 .description = "AH4",
512 .owner = THIS_MODULE,
513 .proto = IPPROTO_AH,
Herbert Xu436a0a42007-10-08 17:25:53 -0700514 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 .init_state = ah_init_state,
516 .destructor = ah_destroy,
517 .input = ah_input,
518 .output = ah_output
519};
520
Alexey Dobriyan32613092009-09-14 12:21:47 +0000521static const struct net_protocol ah4_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 .handler = xfrm4_rcv,
523 .err_handler = ah4_err,
524 .no_policy = 1,
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800525 .netns_ok = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526};
527
528static int __init ah4_init(void)
529{
530 if (xfrm_register_type(&ah_type, AF_INET) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000531 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 return -EAGAIN;
533 }
534 if (inet_add_protocol(&ah4_protocol, IPPROTO_AH) < 0) {
Joe Perches058bd4d2012-03-11 18:36:11 +0000535 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 xfrm_unregister_type(&ah_type, AF_INET);
537 return -EAGAIN;
538 }
539 return 0;
540}
541
542static void __exit ah4_fini(void)
543{
544 if (inet_del_protocol(&ah4_protocol, IPPROTO_AH) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000545 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 if (xfrm_unregister_type(&ah_type, AF_INET) < 0)
Joe Perches058bd4d2012-03-11 18:36:11 +0000547 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548}
549
550module_init(ah4_init);
551module_exit(ah4_fini);
552MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700553MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH);