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Commit | Line | Data |
---|---|---|
afd46503 JP |
1 | #define pr_fmt(fmt) "IPsec: " fmt |
2 | ||
dff3bb06 | 3 | #include <crypto/hash.h> |
07d4ee58 | 4 | #include <linux/err.h> |
1da177e4 | 5 | #include <linux/module.h> |
5a0e3ad6 | 6 | #include <linux/slab.h> |
1da177e4 LT |
7 | #include <net/ip.h> |
8 | #include <net/xfrm.h> | |
9 | #include <net/ah.h> | |
10 | #include <linux/crypto.h> | |
11 | #include <linux/pfkeyv2.h> | |
dff3bb06 | 12 | #include <linux/scatterlist.h> |
1da177e4 | 13 | #include <net/icmp.h> |
14c85021 | 14 | #include <net/protocol.h> |
1da177e4 | 15 | |
dff3bb06 SK |
16 | struct 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 | ||
23 | static 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 | ||
42 | static inline u8 *ah_tmp_auth(void *tmp, unsigned int offset) | |
43 | { | |
44 | return tmp + offset; | |
45 | } | |
46 | ||
47 | static 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 | ||
53 | static 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 | ||
66 | static 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 | } | |
1da177e4 LT |
73 | |
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 | ||
b71d1d42 | 78 | static int ip_clear_mutable_options(const struct iphdr *iph, __be32 *daddr) |
1da177e4 | 79 | { |
5e73ea1a | 80 | unsigned char *optptr = (unsigned char *)(iph+1); |
1da177e4 LT |
81 | 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. */ | |
11a03f78 | 99 | case IPOPT_CIPSO: |
1da177e4 LT |
100 | 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: | |
96fe1c02 | 110 | memset(optptr, 0, optlen); |
1da177e4 LT |
111 | } |
112 | l -= optlen; | |
113 | optptr += optlen; | |
114 | } | |
115 | return 0; | |
116 | } | |
117 | ||
dff3bb06 SK |
118 | static 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 | ||
dff3bb06 SK |
141 | kfree(AH_SKB_CB(skb)->tmp); |
142 | xfrm_output_resume(skb, err); | |
143 | } | |
144 | ||
1da177e4 LT |
145 | static int ah_output(struct xfrm_state *x, struct sk_buff *skb) |
146 | { | |
147 | int err; | |
dff3bb06 SK |
148 | 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; | |
1da177e4 LT |
155 | struct iphdr *iph, *top_iph; |
156 | struct ip_auth_hdr *ah; | |
157 | struct ah_data *ahp; | |
d4d573d0 FD |
158 | int seqhi_len = 0; |
159 | __be32 *seqhi; | |
160 | int sglists = 0; | |
161 | struct scatterlist *seqhisg; | |
dff3bb06 SK |
162 | |
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; | |
1da177e4 | 169 | |
7b277b1a | 170 | skb_push(skb, -skb_network_offset(skb)); |
dff3bb06 SK |
171 | ah = ip_auth_hdr(skb); |
172 | ihl = ip_hdrlen(skb); | |
173 | ||
d4d573d0 FD |
174 | if (x->props.flags & XFRM_STATE_ESN) { |
175 | sglists = 1; | |
176 | seqhi_len = sizeof(*seqhi); | |
177 | } | |
dff3bb06 | 178 | err = -ENOMEM; |
d4d573d0 | 179 | iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + seqhi_len); |
dff3bb06 SK |
180 | if (!iph) |
181 | goto out; | |
d4d573d0 FD |
182 | seqhi = (__be32 *)((char *)iph + ihl); |
183 | icv = ah_tmp_icv(ahash, seqhi, seqhi_len); | |
dff3bb06 SK |
184 | req = ah_tmp_req(ahash, icv); |
185 | sg = ah_req_sg(ahash, req); | |
d4d573d0 | 186 | seqhisg = sg + nfrags; |
dff3bb06 SK |
187 | |
188 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
189 | ||
eddc9ec5 | 190 | top_iph = ip_hdr(skb); |
1da177e4 LT |
191 | |
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) | |
dff3bb06 | 201 | goto out_free; |
1da177e4 LT |
202 | } |
203 | ||
37fedd3a HX |
204 | ah->nexthdr = *skb_mac_header(skb); |
205 | *skb_mac_header(skb) = IPPROTO_AH; | |
1da177e4 LT |
206 | |
207 | top_iph->tos = 0; | |
208 | top_iph->tot_len = htons(skb->len); | |
209 | top_iph->frag_off = 0; | |
210 | top_iph->ttl = 0; | |
1da177e4 LT |
211 | top_iph->check = 0; |
212 | ||
fa9921e4 ND |
213 | 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; | |
1da177e4 LT |
217 | |
218 | ah->reserved = 0; | |
219 | ah->spi = x->id.spi; | |
1ce3644a | 220 | ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); |
b7c6538c | 221 | |
d4d573d0 FD |
222 | sg_init_table(sg, nfrags + sglists); |
223 | skb_to_sgvec_nomark(skb, sg, 0, skb->len); | |
b7c6538c | 224 | |
d4d573d0 FD |
225 | 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); | |
dff3bb06 SK |
231 | 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); | |
1da177e4 LT |
246 | |
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 | ||
dff3bb06 SK |
255 | out_free: |
256 | kfree(iph); | |
257 | out: | |
1da177e4 LT |
258 | return err; |
259 | } | |
260 | ||
dff3bb06 SK |
261 | static 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 | ||
b7ea81a5 NB |
281 | err = ah->nexthdr; |
282 | ||
dff3bb06 SK |
283 | skb->network_header += ah_hlen; |
284 | memcpy(skb_network_header(skb), work_iph, ihl); | |
285 | __skb_pull(skb, ah_hlen + ihl); | |
7143dfac LR |
286 | |
287 | if (x->props.mode == XFRM_MODE_TUNNEL) | |
288 | skb_reset_transport_header(skb); | |
289 | else | |
290 | skb_set_transport_header(skb, -ihl); | |
dff3bb06 SK |
291 | out: |
292 | kfree(AH_SKB_CB(skb)->tmp); | |
293 | xfrm_input_resume(skb, err); | |
294 | } | |
295 | ||
e695633e | 296 | static int ah_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 LT |
297 | { |
298 | int ah_hlen; | |
31a4ab93 | 299 | int ihl; |
631a6698 | 300 | int nexthdr; |
dff3bb06 SK |
301 | 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; | |
1da177e4 LT |
309 | struct ip_auth_hdr *ah; |
310 | struct ah_data *ahp; | |
dff3bb06 | 311 | int err = -ENOMEM; |
d8b2a860 FD |
312 | int seqhi_len = 0; |
313 | __be32 *seqhi; | |
314 | int sglists = 0; | |
315 | struct scatterlist *seqhisg; | |
1da177e4 | 316 | |
87bdc48d | 317 | if (!pskb_may_pull(skb, sizeof(*ah))) |
1da177e4 LT |
318 | goto out; |
319 | ||
87bdc48d | 320 | ah = (struct ip_auth_hdr *)skb->data; |
1da177e4 | 321 | ahp = x->data; |
dff3bb06 SK |
322 | ahash = ahp->ahash; |
323 | ||
631a6698 | 324 | nexthdr = ah->nexthdr; |
1da177e4 | 325 | ah_hlen = (ah->hdrlen + 2) << 2; |
e905a9ed | 326 | |
fa9921e4 ND |
327 | 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 | } | |
1da177e4 LT |
336 | |
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. */ | |
14bbd6a5 | 342 | if (skb_unclone(skb, GFP_ATOMIC)) |
1da177e4 LT |
343 | goto out; |
344 | ||
345 | skb->ip_summed = CHECKSUM_NONE; | |
346 | ||
dff3bb06 SK |
347 | |
348 | if ((err = skb_cow_data(skb, 0, &trailer)) < 0) | |
349 | goto out; | |
350 | nfrags = err; | |
351 | ||
4b0ef1f2 DH |
352 | ah = (struct ip_auth_hdr *)skb->data; |
353 | iph = ip_hdr(skb); | |
354 | ihl = ip_hdrlen(skb); | |
355 | ||
d8b2a860 FD |
356 | 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); | |
94c10f0e DM |
363 | if (!work_iph) { |
364 | err = -ENOMEM; | |
dff3bb06 | 365 | goto out; |
94c10f0e | 366 | } |
dff3bb06 | 367 | |
d8b2a860 FD |
368 | seqhi = (__be32 *)((char *)work_iph + ihl); |
369 | auth_data = ah_tmp_auth(seqhi, seqhi_len); | |
dff3bb06 SK |
370 | icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len); |
371 | req = ah_tmp_req(ahash, icv); | |
372 | sg = ah_req_sg(ahash, req); | |
d8b2a860 | 373 | seqhisg = sg + nfrags; |
1da177e4 | 374 | |
dff3bb06 SK |
375 | memcpy(work_iph, iph, ihl); |
376 | memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); | |
377 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
1da177e4 LT |
378 | |
379 | iph->ttl = 0; | |
380 | iph->tos = 0; | |
381 | iph->frag_off = 0; | |
382 | iph->check = 0; | |
31a4ab93 | 383 | if (ihl > sizeof(*iph)) { |
d5a0a1e3 | 384 | __be32 dummy; |
dff3bb06 SK |
385 | err = ip_clear_mutable_options(iph, &dummy); |
386 | if (err) | |
387 | goto out_free; | |
1da177e4 | 388 | } |
0ebea8ef | 389 | |
dff3bb06 | 390 | skb_push(skb, ihl); |
e905a9ed | 391 | |
d8b2a860 FD |
392 | sg_init_table(sg, nfrags + sglists); |
393 | skb_to_sgvec_nomark(skb, sg, 0, skb->len); | |
dff3bb06 | 394 | |
d8b2a860 FD |
395 | if (x->props.flags & XFRM_STATE_ESN) { |
396 | /* Attach seqhi sg right after packet payload */ | |
397 | *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; | |
398 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
399 | } | |
400 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); | |
dff3bb06 SK |
401 | ahash_request_set_callback(req, 0, ah_input_done, skb); |
402 | ||
403 | AH_SKB_CB(skb)->tmp = work_iph; | |
404 | ||
405 | err = crypto_ahash_digest(req); | |
406 | if (err) { | |
407 | if (err == -EINPROGRESS) | |
408 | goto out; | |
409 | ||
dff3bb06 | 410 | goto out_free; |
1da177e4 | 411 | } |
0ebea8ef | 412 | |
dff3bb06 | 413 | err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; |
0ebea8ef | 414 | if (err) |
dff3bb06 | 415 | goto out_free; |
0ebea8ef | 416 | |
b0e380b1 | 417 | skb->network_header += ah_hlen; |
dff3bb06 | 418 | memcpy(skb_network_header(skb), work_iph, ihl); |
31a4ab93 | 419 | __skb_pull(skb, ah_hlen + ihl); |
7143dfac LR |
420 | if (x->props.mode == XFRM_MODE_TUNNEL) |
421 | skb_reset_transport_header(skb); | |
422 | else | |
423 | skb_set_transport_header(skb, -ihl); | |
1da177e4 | 424 | |
dff3bb06 | 425 | err = nexthdr; |
1da177e4 | 426 | |
dff3bb06 SK |
427 | out_free: |
428 | kfree (work_iph); | |
1da177e4 | 429 | out: |
07d4ee58 | 430 | return err; |
1da177e4 LT |
431 | } |
432 | ||
e5b56454 | 433 | static int ah4_err(struct sk_buff *skb, u32 info) |
1da177e4 | 434 | { |
4fb236ba | 435 | struct net *net = dev_net(skb->dev); |
b71d1d42 | 436 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
d9319100 | 437 | struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2)); |
1da177e4 LT |
438 | struct xfrm_state *x; |
439 | ||
55be7a9c DM |
440 | switch (icmp_hdr(skb)->type) { |
441 | case ICMP_DEST_UNREACH: | |
442 | if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) | |
e5b56454 | 443 | return 0; |
55be7a9c DM |
444 | case ICMP_REDIRECT: |
445 | break; | |
446 | default: | |
e5b56454 | 447 | return 0; |
55be7a9c | 448 | } |
1da177e4 | 449 | |
b71d1d42 ED |
450 | x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, |
451 | ah->spi, IPPROTO_AH, AF_INET); | |
1da177e4 | 452 | if (!x) |
e5b56454 | 453 | return 0; |
55be7a9c | 454 | |
387aa65a | 455 | if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) |
55be7a9c | 456 | ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_AH, 0); |
387aa65a | 457 | else |
55be7a9c | 458 | ipv4_redirect(skb, net, 0, 0, IPPROTO_AH, 0); |
1da177e4 | 459 | xfrm_state_put(x); |
e5b56454 SK |
460 | |
461 | return 0; | |
1da177e4 LT |
462 | } |
463 | ||
72cb6962 | 464 | static int ah_init_state(struct xfrm_state *x) |
1da177e4 LT |
465 | { |
466 | struct ah_data *ahp = NULL; | |
467 | struct xfrm_algo_desc *aalg_desc; | |
dff3bb06 | 468 | struct crypto_ahash *ahash; |
1da177e4 LT |
469 | |
470 | if (!x->aalg) | |
471 | goto error; | |
472 | ||
1da177e4 LT |
473 | if (x->encap) |
474 | goto error; | |
475 | ||
0da974f4 | 476 | ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); |
dff3bb06 | 477 | if (!ahp) |
1da177e4 LT |
478 | return -ENOMEM; |
479 | ||
dff3bb06 SK |
480 | ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); |
481 | if (IS_ERR(ahash)) | |
07d4ee58 HX |
482 | goto error; |
483 | ||
dff3bb06 SK |
484 | ahp->ahash = ahash; |
485 | if (crypto_ahash_setkey(ahash, x->aalg->alg_key, | |
486 | (x->aalg->alg_key_len + 7) / 8)) | |
1da177e4 | 487 | goto error; |
e905a9ed | 488 | |
1da177e4 LT |
489 | /* |
490 | * Lookup the algorithm description maintained by xfrm_algo, | |
491 | * verify crypto transform properties, and store information | |
492 | * we need for AH processing. This lookup cannot fail here | |
dff3bb06 | 493 | * after a successful crypto_alloc_ahash(). |
1da177e4 LT |
494 | */ |
495 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
496 | BUG_ON(!aalg_desc); | |
497 | ||
498 | if (aalg_desc->uinfo.auth.icv_fullbits/8 != | |
dff3bb06 | 499 | crypto_ahash_digestsize(ahash)) { |
afd46503 JP |
500 | pr_info("%s: %s digestsize %u != %hu\n", |
501 | __func__, x->aalg->alg_name, | |
502 | crypto_ahash_digestsize(ahash), | |
503 | aalg_desc->uinfo.auth.icv_fullbits / 8); | |
1da177e4 LT |
504 | goto error; |
505 | } | |
e905a9ed | 506 | |
1da177e4 | 507 | ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; |
8f8a088c | 508 | ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; |
e905a9ed | 509 | |
fa9921e4 ND |
510 | 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); | |
7e49e6de | 516 | if (x->props.mode == XFRM_MODE_TUNNEL) |
1da177e4 LT |
517 | x->props.header_len += sizeof(struct iphdr); |
518 | x->data = ahp; | |
519 | ||
520 | return 0; | |
521 | ||
522 | error: | |
523 | if (ahp) { | |
dff3bb06 | 524 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
525 | kfree(ahp); |
526 | } | |
527 | return -EINVAL; | |
528 | } | |
529 | ||
530 | static void ah_destroy(struct xfrm_state *x) | |
531 | { | |
532 | struct ah_data *ahp = x->data; | |
533 | ||
534 | if (!ahp) | |
535 | return; | |
536 | ||
dff3bb06 | 537 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
538 | kfree(ahp); |
539 | } | |
540 | ||
e5b56454 SK |
541 | static int ah4_rcv_cb(struct sk_buff *skb, int err) |
542 | { | |
543 | return 0; | |
544 | } | |
1da177e4 | 545 | |
533cb5b0 | 546 | static const struct xfrm_type ah_type = |
1da177e4 LT |
547 | { |
548 | .description = "AH4", | |
549 | .owner = THIS_MODULE, | |
550 | .proto = IPPROTO_AH, | |
436a0a40 | 551 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
552 | .init_state = ah_init_state, |
553 | .destructor = ah_destroy, | |
554 | .input = ah_input, | |
555 | .output = ah_output | |
556 | }; | |
557 | ||
e5b56454 | 558 | static struct xfrm4_protocol ah4_protocol = { |
1da177e4 | 559 | .handler = xfrm4_rcv, |
e5b56454 SK |
560 | .input_handler = xfrm_input, |
561 | .cb_handler = ah4_rcv_cb, | |
1da177e4 | 562 | .err_handler = ah4_err, |
e5b56454 | 563 | .priority = 0, |
1da177e4 LT |
564 | }; |
565 | ||
566 | static int __init ah4_init(void) | |
567 | { | |
568 | if (xfrm_register_type(&ah_type, AF_INET) < 0) { | |
058bd4d2 | 569 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
570 | return -EAGAIN; |
571 | } | |
e5b56454 | 572 | if (xfrm4_protocol_register(&ah4_protocol, IPPROTO_AH) < 0) { |
058bd4d2 | 573 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
574 | xfrm_unregister_type(&ah_type, AF_INET); |
575 | return -EAGAIN; | |
576 | } | |
577 | return 0; | |
578 | } | |
579 | ||
580 | static void __exit ah4_fini(void) | |
581 | { | |
e5b56454 | 582 | if (xfrm4_protocol_deregister(&ah4_protocol, IPPROTO_AH) < 0) |
058bd4d2 | 583 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 | 584 | if (xfrm_unregister_type(&ah_type, AF_INET) < 0) |
058bd4d2 | 585 | pr_info("%s: can't remove xfrm type\n", __func__); |
1da177e4 LT |
586 | } |
587 | ||
588 | module_init(ah4_init); | |
589 | module_exit(ah4_fini); | |
590 | MODULE_LICENSE("GPL"); | |
d3d6dd3a | 591 | MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_AH); |