Commit | Line | Data |
---|---|---|
afd46503 JP |
1 | #define pr_fmt(fmt) "IPsec: " fmt |
2 | ||
38320c70 HX |
3 | #include <crypto/aead.h> |
4 | #include <crypto/authenc.h> | |
6b7326c8 | 5 | #include <linux/err.h> |
1da177e4 LT |
6 | #include <linux/module.h> |
7 | #include <net/ip.h> | |
8 | #include <net/xfrm.h> | |
9 | #include <net/esp.h> | |
72998d8c | 10 | #include <linux/scatterlist.h> |
a02a6422 | 11 | #include <linux/kernel.h> |
1da177e4 | 12 | #include <linux/pfkeyv2.h> |
38320c70 HX |
13 | #include <linux/rtnetlink.h> |
14 | #include <linux/slab.h> | |
b7c6538c | 15 | #include <linux/spinlock.h> |
2017a72c | 16 | #include <linux/in6.h> |
1da177e4 | 17 | #include <net/icmp.h> |
14c85021 | 18 | #include <net/protocol.h> |
1da177e4 LT |
19 | #include <net/udp.h> |
20 | ||
38320c70 HX |
21 | struct 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 | ||
d979e20f MW |
28 | static u32 esp4_get_mtu(struct xfrm_state *x, int mtu); |
29 | ||
38320c70 HX |
30 | /* |
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 | */ | |
0dc49e9b | 38 | static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqhilen) |
38320c70 HX |
39 | { |
40 | unsigned int len; | |
41 | ||
0dc49e9b SK |
42 | len = seqhilen; |
43 | ||
44 | len += crypto_aead_ivsize(aead); | |
45 | ||
38320c70 HX |
46 | if (len) { |
47 | len += crypto_aead_alignmask(aead) & | |
48 | ~(crypto_tfm_ctx_alignment() - 1); | |
49 | len = ALIGN(len, crypto_tfm_ctx_alignment()); | |
50 | } | |
51 | ||
7021b2e1 | 52 | len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); |
38320c70 HX |
53 | len = ALIGN(len, __alignof__(struct scatterlist)); |
54 | ||
55 | len += sizeof(struct scatterlist) * nfrags; | |
56 | ||
57 | return kmalloc(len, GFP_ATOMIC); | |
58 | } | |
59 | ||
0dc49e9b SK |
60 | static inline __be32 *esp_tmp_seqhi(void *tmp) |
61 | { | |
62 | return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32)); | |
63 | } | |
64 | static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen) | |
38320c70 HX |
65 | { |
66 | return crypto_aead_ivsize(aead) ? | |
0dc49e9b SK |
67 | PTR_ALIGN((u8 *)tmp + seqhilen, |
68 | crypto_aead_alignmask(aead) + 1) : tmp + seqhilen; | |
38320c70 HX |
69 | } |
70 | ||
38320c70 HX |
71 | static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) |
72 | { | |
73 | struct aead_request *req; | |
74 | ||
75 | req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), | |
76 | crypto_tfm_ctx_alignment()); | |
77 | aead_request_set_tfm(req, aead); | |
78 | return req; | |
79 | } | |
80 | ||
81 | static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, | |
82 | struct aead_request *req) | |
83 | { | |
84 | return (void *)ALIGN((unsigned long)(req + 1) + | |
85 | crypto_aead_reqsize(aead), | |
86 | __alignof__(struct scatterlist)); | |
87 | } | |
88 | ||
38320c70 HX |
89 | static void esp_output_done(struct crypto_async_request *base, int err) |
90 | { | |
91 | struct sk_buff *skb = base->data; | |
92 | ||
93 | kfree(ESP_SKB_CB(skb)->tmp); | |
94 | xfrm_output_resume(skb, err); | |
95 | } | |
96 | ||
7021b2e1 HX |
97 | /* Move ESP header back into place. */ |
98 | static void esp_restore_header(struct sk_buff *skb, unsigned int offset) | |
99 | { | |
100 | struct ip_esp_hdr *esph = (void *)(skb->data + offset); | |
101 | void *tmp = ESP_SKB_CB(skb)->tmp; | |
102 | __be32 *seqhi = esp_tmp_seqhi(tmp); | |
103 | ||
104 | esph->seq_no = esph->spi; | |
105 | esph->spi = *seqhi; | |
106 | } | |
107 | ||
108 | static void esp_output_restore_header(struct sk_buff *skb) | |
109 | { | |
110 | esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32)); | |
111 | } | |
112 | ||
113 | static void esp_output_done_esn(struct crypto_async_request *base, int err) | |
114 | { | |
115 | struct sk_buff *skb = base->data; | |
116 | ||
117 | esp_output_restore_header(skb); | |
118 | esp_output_done(base, err); | |
119 | } | |
120 | ||
1da177e4 LT |
121 | static int esp_output(struct xfrm_state *x, struct sk_buff *skb) |
122 | { | |
123 | int err; | |
1da177e4 | 124 | struct ip_esp_hdr *esph; |
38320c70 | 125 | struct crypto_aead *aead; |
7021b2e1 | 126 | struct aead_request *req; |
38320c70 | 127 | struct scatterlist *sg; |
1da177e4 | 128 | struct sk_buff *trailer; |
38320c70 HX |
129 | void *tmp; |
130 | u8 *iv; | |
27a884dc | 131 | u8 *tail; |
1da177e4 LT |
132 | int blksize; |
133 | int clen; | |
134 | int alen; | |
d979e20f | 135 | int plen; |
7021b2e1 | 136 | int ivlen; |
d979e20f | 137 | int tfclen; |
1da177e4 | 138 | int nfrags; |
0dc49e9b | 139 | int assoclen; |
0dc49e9b SK |
140 | int seqhilen; |
141 | __be32 *seqhi; | |
7021b2e1 | 142 | __be64 seqno; |
1da177e4 | 143 | |
7b277b1a | 144 | /* skb is pure payload to encrypt */ |
1da177e4 | 145 | |
1c5ad13f | 146 | aead = x->data; |
38320c70 | 147 | alen = crypto_aead_authsize(aead); |
7021b2e1 | 148 | ivlen = crypto_aead_ivsize(aead); |
38320c70 | 149 | |
d979e20f MW |
150 | tfclen = 0; |
151 | if (x->tfcpad) { | |
152 | struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); | |
153 | u32 padto; | |
154 | ||
155 | padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); | |
156 | if (skb->len < padto) | |
157 | tfclen = padto - skb->len; | |
158 | } | |
38320c70 | 159 | blksize = ALIGN(crypto_aead_blocksize(aead), 4); |
d979e20f | 160 | clen = ALIGN(skb->len + 2 + tfclen, blksize); |
d979e20f | 161 | plen = clen - skb->len - tfclen; |
38320c70 | 162 | |
d979e20f MW |
163 | err = skb_cow_data(skb, tfclen + plen + alen, &trailer); |
164 | if (err < 0) | |
38320c70 HX |
165 | goto error; |
166 | nfrags = err; | |
1da177e4 | 167 | |
0dc49e9b | 168 | assoclen = sizeof(*esph); |
0dc49e9b SK |
169 | seqhilen = 0; |
170 | ||
171 | if (x->props.flags & XFRM_STATE_ESN) { | |
0dc49e9b SK |
172 | seqhilen += sizeof(__be32); |
173 | assoclen += seqhilen; | |
174 | } | |
175 | ||
7021b2e1 | 176 | tmp = esp_alloc_tmp(aead, nfrags, seqhilen); |
06848c10 WY |
177 | if (!tmp) { |
178 | err = -ENOMEM; | |
1da177e4 | 179 | goto error; |
06848c10 | 180 | } |
1da177e4 | 181 | |
0dc49e9b SK |
182 | seqhi = esp_tmp_seqhi(tmp); |
183 | iv = esp_tmp_iv(aead, tmp, seqhilen); | |
7021b2e1 HX |
184 | req = esp_tmp_req(aead, iv); |
185 | sg = esp_req_sg(aead, req); | |
38320c70 | 186 | |
1da177e4 | 187 | /* Fill padding... */ |
27a884dc | 188 | tail = skb_tail_pointer(trailer); |
d979e20f MW |
189 | if (tfclen) { |
190 | memset(tail, 0, tfclen); | |
191 | tail += tfclen; | |
192 | } | |
1da177e4 LT |
193 | do { |
194 | int i; | |
d979e20f | 195 | for (i = 0; i < plen - 2; i++) |
27a884dc | 196 | tail[i] = i + 1; |
1da177e4 | 197 | } while (0); |
d979e20f MW |
198 | tail[plen - 2] = plen - 2; |
199 | tail[plen - 1] = *skb_mac_header(skb); | |
38320c70 | 200 | pskb_put(skb, trailer, clen - skb->len + alen); |
1da177e4 | 201 | |
7b277b1a | 202 | skb_push(skb, -skb_network_offset(skb)); |
87bdc48d | 203 | esph = ip_esp_hdr(skb); |
37fedd3a | 204 | *skb_mac_header(skb) = IPPROTO_ESP; |
1da177e4 LT |
205 | |
206 | /* this is non-NULL only with UDP Encapsulation */ | |
207 | if (x->encap) { | |
208 | struct xfrm_encap_tmpl *encap = x->encap; | |
209 | struct udphdr *uh; | |
d5a0a1e3 | 210 | __be32 *udpdata32; |
5e226e4d | 211 | __be16 sport, dport; |
38320c70 HX |
212 | int encap_type; |
213 | ||
214 | spin_lock_bh(&x->lock); | |
215 | sport = encap->encap_sport; | |
216 | dport = encap->encap_dport; | |
217 | encap_type = encap->encap_type; | |
218 | spin_unlock_bh(&x->lock); | |
1da177e4 LT |
219 | |
220 | uh = (struct udphdr *)esph; | |
38320c70 HX |
221 | uh->source = sport; |
222 | uh->dest = dport; | |
223 | uh->len = htons(skb->len - skb_transport_offset(skb)); | |
1da177e4 LT |
224 | uh->check = 0; |
225 | ||
38320c70 | 226 | switch (encap_type) { |
1da177e4 LT |
227 | default: |
228 | case UDP_ENCAP_ESPINUDP: | |
229 | esph = (struct ip_esp_hdr *)(uh + 1); | |
230 | break; | |
231 | case UDP_ENCAP_ESPINUDP_NON_IKE: | |
d5a0a1e3 | 232 | udpdata32 = (__be32 *)(uh + 1); |
1da177e4 LT |
233 | udpdata32[0] = udpdata32[1] = 0; |
234 | esph = (struct ip_esp_hdr *)(udpdata32 + 2); | |
235 | break; | |
236 | } | |
237 | ||
37fedd3a HX |
238 | *skb_mac_header(skb) = IPPROTO_UDP; |
239 | } | |
1da177e4 | 240 | |
1ce3644a | 241 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); |
1da177e4 | 242 | |
7021b2e1 HX |
243 | aead_request_set_callback(req, 0, esp_output_done, skb); |
244 | ||
245 | /* For ESN we move the header forward by 4 bytes to | |
246 | * accomodate the high bits. We will move it back after | |
247 | * encryption. | |
248 | */ | |
249 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
250 | esph = (void *)(skb_transport_header(skb) - sizeof(__be32)); | |
251 | *seqhi = esph->spi; | |
252 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); | |
253 | aead_request_set_callback(req, 0, esp_output_done_esn, skb); | |
254 | } | |
255 | ||
256 | esph->spi = x->id.spi; | |
257 | ||
38320c70 HX |
258 | sg_init_table(sg, nfrags); |
259 | skb_to_sgvec(skb, sg, | |
7021b2e1 HX |
260 | (unsigned char *)esph - skb->data, |
261 | assoclen + ivlen + clen + alen); | |
0dc49e9b | 262 | |
7021b2e1 HX |
263 | aead_request_set_crypt(req, sg, sg, ivlen + clen, iv); |
264 | aead_request_set_ad(req, assoclen); | |
265 | ||
266 | seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + | |
267 | ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); | |
268 | ||
269 | memset(iv, 0, ivlen); | |
270 | memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8), | |
271 | min(ivlen, 8)); | |
38320c70 HX |
272 | |
273 | ESP_SKB_CB(skb)->tmp = tmp; | |
7021b2e1 HX |
274 | err = crypto_aead_encrypt(req); |
275 | ||
276 | switch (err) { | |
277 | case -EINPROGRESS: | |
38320c70 | 278 | goto error; |
1da177e4 | 279 | |
7021b2e1 | 280 | case -EBUSY: |
38320c70 | 281 | err = NET_XMIT_DROP; |
7021b2e1 HX |
282 | break; |
283 | ||
284 | case 0: | |
285 | if ((x->props.flags & XFRM_STATE_ESN)) | |
286 | esp_output_restore_header(skb); | |
287 | } | |
1da177e4 | 288 | |
38320c70 | 289 | kfree(tmp); |
b7c6538c | 290 | |
1da177e4 LT |
291 | error: |
292 | return err; | |
293 | } | |
294 | ||
38320c70 | 295 | static int esp_input_done2(struct sk_buff *skb, int err) |
1da177e4 | 296 | { |
b71d1d42 | 297 | const struct iphdr *iph; |
38320c70 | 298 | struct xfrm_state *x = xfrm_input_state(skb); |
1c5ad13f | 299 | struct crypto_aead *aead = x->data; |
38320c70 HX |
300 | int alen = crypto_aead_authsize(aead); |
301 | int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); | |
302 | int elen = skb->len - hlen; | |
31a4ab93 | 303 | int ihl; |
4bf05ece | 304 | u8 nexthdr[2]; |
4bf05ece | 305 | int padlen; |
1da177e4 | 306 | |
38320c70 | 307 | kfree(ESP_SKB_CB(skb)->tmp); |
0ebea8ef | 308 | |
6b7326c8 | 309 | if (unlikely(err)) |
668dc8af | 310 | goto out; |
1da177e4 | 311 | |
4bf05ece HX |
312 | if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) |
313 | BUG(); | |
1da177e4 | 314 | |
668dc8af | 315 | err = -EINVAL; |
4bf05ece | 316 | padlen = nexthdr[0]; |
38320c70 | 317 | if (padlen + 2 + alen >= elen) |
4bf05ece | 318 | goto out; |
1da177e4 | 319 | |
e905a9ed | 320 | /* ... check padding bits here. Silly. :-) */ |
1da177e4 | 321 | |
eddc9ec5 | 322 | iph = ip_hdr(skb); |
31a4ab93 HX |
323 | ihl = iph->ihl * 4; |
324 | ||
752c1f4c HX |
325 | if (x->encap) { |
326 | struct xfrm_encap_tmpl *encap = x->encap; | |
d56f90a7 | 327 | struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); |
752c1f4c HX |
328 | |
329 | /* | |
330 | * 1) if the NAT-T peer's IP or port changed then | |
331 | * advertize the change to the keying daemon. | |
332 | * This is an inbound SA, so just compare | |
333 | * SRC ports. | |
334 | */ | |
335 | if (iph->saddr != x->props.saddr.a4 || | |
336 | uh->source != encap->encap_sport) { | |
337 | xfrm_address_t ipaddr; | |
338 | ||
339 | ipaddr.a4 = iph->saddr; | |
340 | km_new_mapping(x, &ipaddr, uh->source); | |
e905a9ed | 341 | |
752c1f4c HX |
342 | /* XXX: perhaps add an extra |
343 | * policy check here, to see | |
344 | * if we should allow or | |
345 | * reject a packet from a | |
346 | * different source | |
347 | * address/port. | |
348 | */ | |
1da177e4 | 349 | } |
e905a9ed | 350 | |
752c1f4c HX |
351 | /* |
352 | * 2) ignore UDP/TCP checksums in case | |
353 | * of NAT-T in Transport Mode, or | |
354 | * perform other post-processing fixes | |
355 | * as per draft-ietf-ipsec-udp-encaps-06, | |
356 | * section 3.1.2 | |
357 | */ | |
8bd17075 | 358 | if (x->props.mode == XFRM_MODE_TRANSPORT) |
752c1f4c | 359 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
1da177e4 LT |
360 | } |
361 | ||
4bf05ece | 362 | pskb_trim(skb, skb->len - alen - padlen - 2); |
38320c70 | 363 | __skb_pull(skb, hlen); |
7143dfac LR |
364 | if (x->props.mode == XFRM_MODE_TUNNEL) |
365 | skb_reset_transport_header(skb); | |
366 | else | |
367 | skb_set_transport_header(skb, -ihl); | |
4bf05ece | 368 | |
38320c70 HX |
369 | err = nexthdr[1]; |
370 | ||
371 | /* RFC4303: Drop dummy packets without any error */ | |
372 | if (err == IPPROTO_NONE) | |
373 | err = -EINVAL; | |
374 | ||
375 | out: | |
376 | return err; | |
377 | } | |
378 | ||
379 | static void esp_input_done(struct crypto_async_request *base, int err) | |
380 | { | |
381 | struct sk_buff *skb = base->data; | |
382 | ||
383 | xfrm_input_resume(skb, esp_input_done2(skb, err)); | |
384 | } | |
385 | ||
7021b2e1 HX |
386 | static void esp_input_restore_header(struct sk_buff *skb) |
387 | { | |
388 | esp_restore_header(skb, 0); | |
389 | __skb_pull(skb, 4); | |
390 | } | |
391 | ||
392 | static void esp_input_done_esn(struct crypto_async_request *base, int err) | |
393 | { | |
394 | struct sk_buff *skb = base->data; | |
395 | ||
396 | esp_input_restore_header(skb); | |
397 | esp_input_done(base, err); | |
398 | } | |
399 | ||
38320c70 HX |
400 | /* |
401 | * Note: detecting truncated vs. non-truncated authentication data is very | |
402 | * expensive, so we only support truncated data, which is the recommended | |
403 | * and common case. | |
404 | */ | |
405 | static int esp_input(struct xfrm_state *x, struct sk_buff *skb) | |
406 | { | |
407 | struct ip_esp_hdr *esph; | |
1c5ad13f | 408 | struct crypto_aead *aead = x->data; |
38320c70 HX |
409 | struct aead_request *req; |
410 | struct sk_buff *trailer; | |
7021b2e1 HX |
411 | int ivlen = crypto_aead_ivsize(aead); |
412 | int elen = skb->len - sizeof(*esph) - ivlen; | |
38320c70 | 413 | int nfrags; |
0dc49e9b | 414 | int assoclen; |
0dc49e9b SK |
415 | int seqhilen; |
416 | __be32 *seqhi; | |
38320c70 HX |
417 | void *tmp; |
418 | u8 *iv; | |
419 | struct scatterlist *sg; | |
38320c70 HX |
420 | int err = -EINVAL; |
421 | ||
7021b2e1 | 422 | if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) |
38320c70 HX |
423 | goto out; |
424 | ||
425 | if (elen <= 0) | |
426 | goto out; | |
427 | ||
05006e8c FF |
428 | err = skb_cow_data(skb, 0, &trailer); |
429 | if (err < 0) | |
38320c70 | 430 | goto out; |
05006e8c | 431 | |
38320c70 HX |
432 | nfrags = err; |
433 | ||
0dc49e9b | 434 | assoclen = sizeof(*esph); |
0dc49e9b SK |
435 | seqhilen = 0; |
436 | ||
437 | if (x->props.flags & XFRM_STATE_ESN) { | |
0dc49e9b SK |
438 | seqhilen += sizeof(__be32); |
439 | assoclen += seqhilen; | |
440 | } | |
441 | ||
38320c70 | 442 | err = -ENOMEM; |
7021b2e1 | 443 | tmp = esp_alloc_tmp(aead, nfrags, seqhilen); |
38320c70 HX |
444 | if (!tmp) |
445 | goto out; | |
446 | ||
447 | ESP_SKB_CB(skb)->tmp = tmp; | |
0dc49e9b SK |
448 | seqhi = esp_tmp_seqhi(tmp); |
449 | iv = esp_tmp_iv(aead, tmp, seqhilen); | |
38320c70 | 450 | req = esp_tmp_req(aead, iv); |
7021b2e1 | 451 | sg = esp_req_sg(aead, req); |
38320c70 HX |
452 | |
453 | skb->ip_summed = CHECKSUM_NONE; | |
454 | ||
455 | esph = (struct ip_esp_hdr *)skb->data; | |
456 | ||
7021b2e1 | 457 | aead_request_set_callback(req, 0, esp_input_done, skb); |
0dc49e9b | 458 | |
7021b2e1 HX |
459 | /* For ESN we move the header forward by 4 bytes to |
460 | * accomodate the high bits. We will move it back after | |
461 | * decryption. | |
462 | */ | |
0dc49e9b | 463 | if ((x->props.flags & XFRM_STATE_ESN)) { |
7021b2e1 HX |
464 | esph = (void *)skb_push(skb, 4); |
465 | *seqhi = esph->spi; | |
466 | esph->spi = esph->seq_no; | |
467 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.input.hi); | |
468 | aead_request_set_callback(req, 0, esp_input_done_esn, skb); | |
469 | } | |
38320c70 | 470 | |
7021b2e1 HX |
471 | sg_init_table(sg, nfrags); |
472 | skb_to_sgvec(skb, sg, 0, skb->len); | |
473 | ||
474 | aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); | |
475 | aead_request_set_ad(req, assoclen); | |
38320c70 HX |
476 | |
477 | err = crypto_aead_decrypt(req); | |
478 | if (err == -EINPROGRESS) | |
479 | goto out; | |
480 | ||
7021b2e1 HX |
481 | if ((x->props.flags & XFRM_STATE_ESN)) |
482 | esp_input_restore_header(skb); | |
483 | ||
38320c70 | 484 | err = esp_input_done2(skb, err); |
1da177e4 LT |
485 | |
486 | out: | |
668dc8af | 487 | return err; |
1da177e4 LT |
488 | } |
489 | ||
c5c25238 | 490 | static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) |
1da177e4 | 491 | { |
1c5ad13f MK |
492 | struct crypto_aead *aead = x->data; |
493 | u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); | |
91657eaf | 494 | unsigned int net_adj; |
0a69452c DB |
495 | |
496 | switch (x->props.mode) { | |
0a69452c | 497 | case XFRM_MODE_TRANSPORT: |
0a69452c | 498 | case XFRM_MODE_BEET: |
91657eaf | 499 | net_adj = sizeof(struct iphdr); |
0a69452c | 500 | break; |
91657eaf BP |
501 | case XFRM_MODE_TUNNEL: |
502 | net_adj = 0; | |
503 | break; | |
504 | default: | |
505 | BUG(); | |
1da177e4 | 506 | } |
0a69452c | 507 | |
1c5ad13f | 508 | return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - |
123b0d1b | 509 | net_adj) & ~(blksize - 1)) + net_adj - 2; |
1da177e4 LT |
510 | } |
511 | ||
827789cb | 512 | static int esp4_err(struct sk_buff *skb, u32 info) |
1da177e4 | 513 | { |
4fb236ba | 514 | struct net *net = dev_net(skb->dev); |
b71d1d42 | 515 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
d9319100 | 516 | struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); |
1da177e4 LT |
517 | struct xfrm_state *x; |
518 | ||
55be7a9c DM |
519 | switch (icmp_hdr(skb)->type) { |
520 | case ICMP_DEST_UNREACH: | |
521 | if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) | |
827789cb | 522 | return 0; |
55be7a9c DM |
523 | case ICMP_REDIRECT: |
524 | break; | |
525 | default: | |
827789cb | 526 | return 0; |
55be7a9c | 527 | } |
1da177e4 | 528 | |
b71d1d42 ED |
529 | x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, |
530 | esph->spi, IPPROTO_ESP, AF_INET); | |
1da177e4 | 531 | if (!x) |
827789cb | 532 | return 0; |
55be7a9c | 533 | |
387aa65a | 534 | if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) |
55be7a9c | 535 | ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0); |
387aa65a | 536 | else |
55be7a9c | 537 | ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0); |
1da177e4 | 538 | xfrm_state_put(x); |
827789cb SK |
539 | |
540 | return 0; | |
1da177e4 LT |
541 | } |
542 | ||
543 | static void esp_destroy(struct xfrm_state *x) | |
544 | { | |
1c5ad13f | 545 | struct crypto_aead *aead = x->data; |
1da177e4 | 546 | |
1c5ad13f | 547 | if (!aead) |
1da177e4 LT |
548 | return; |
549 | ||
1c5ad13f | 550 | crypto_free_aead(aead); |
1da177e4 LT |
551 | } |
552 | ||
1a6509d9 | 553 | static int esp_init_aead(struct xfrm_state *x) |
1da177e4 | 554 | { |
7021b2e1 | 555 | char aead_name[CRYPTO_MAX_ALG_NAME]; |
1a6509d9 HX |
556 | struct crypto_aead *aead; |
557 | int err; | |
558 | ||
7021b2e1 HX |
559 | err = -ENAMETOOLONG; |
560 | if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", | |
561 | x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) | |
562 | goto error; | |
563 | ||
564 | aead = crypto_alloc_aead(aead_name, 0, 0); | |
1a6509d9 HX |
565 | err = PTR_ERR(aead); |
566 | if (IS_ERR(aead)) | |
567 | goto error; | |
568 | ||
1c5ad13f | 569 | x->data = aead; |
1a6509d9 HX |
570 | |
571 | err = crypto_aead_setkey(aead, x->aead->alg_key, | |
572 | (x->aead->alg_key_len + 7) / 8); | |
573 | if (err) | |
574 | goto error; | |
575 | ||
576 | err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); | |
577 | if (err) | |
578 | goto error; | |
579 | ||
580 | error: | |
581 | return err; | |
582 | } | |
583 | ||
584 | static int esp_init_authenc(struct xfrm_state *x) | |
585 | { | |
38320c70 HX |
586 | struct crypto_aead *aead; |
587 | struct crypto_authenc_key_param *param; | |
588 | struct rtattr *rta; | |
589 | char *key; | |
590 | char *p; | |
591 | char authenc_name[CRYPTO_MAX_ALG_NAME]; | |
38320c70 HX |
592 | unsigned int keylen; |
593 | int err; | |
1da177e4 | 594 | |
1a6509d9 | 595 | err = -EINVAL; |
51456b29 | 596 | if (!x->ealg) |
1a6509d9 | 597 | goto error; |
38320c70 | 598 | |
1a6509d9 | 599 | err = -ENAMETOOLONG; |
0dc49e9b SK |
600 | |
601 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
602 | if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, | |
7021b2e1 HX |
603 | "%s%sauthencesn(%s,%s)%s", |
604 | x->geniv ?: "", x->geniv ? "(" : "", | |
0dc49e9b | 605 | x->aalg ? x->aalg->alg_name : "digest_null", |
7021b2e1 HX |
606 | x->ealg->alg_name, |
607 | x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) | |
0dc49e9b SK |
608 | goto error; |
609 | } else { | |
610 | if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, | |
7021b2e1 HX |
611 | "%s%sauthenc(%s,%s)%s", |
612 | x->geniv ?: "", x->geniv ? "(" : "", | |
0dc49e9b | 613 | x->aalg ? x->aalg->alg_name : "digest_null", |
7021b2e1 HX |
614 | x->ealg->alg_name, |
615 | x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) | |
0dc49e9b SK |
616 | goto error; |
617 | } | |
38320c70 HX |
618 | |
619 | aead = crypto_alloc_aead(authenc_name, 0, 0); | |
620 | err = PTR_ERR(aead); | |
621 | if (IS_ERR(aead)) | |
622 | goto error; | |
623 | ||
1c5ad13f | 624 | x->data = aead; |
38320c70 HX |
625 | |
626 | keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + | |
627 | (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); | |
628 | err = -ENOMEM; | |
629 | key = kmalloc(keylen, GFP_KERNEL); | |
630 | if (!key) | |
631 | goto error; | |
632 | ||
633 | p = key; | |
634 | rta = (void *)p; | |
635 | rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; | |
636 | rta->rta_len = RTA_LENGTH(sizeof(*param)); | |
637 | param = RTA_DATA(rta); | |
638 | p += RTA_SPACE(sizeof(*param)); | |
639 | ||
1da177e4 LT |
640 | if (x->aalg) { |
641 | struct xfrm_algo_desc *aalg_desc; | |
642 | ||
38320c70 HX |
643 | memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); |
644 | p += (x->aalg->alg_key_len + 7) / 8; | |
1da177e4 LT |
645 | |
646 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
647 | BUG_ON(!aalg_desc); | |
648 | ||
38320c70 | 649 | err = -EINVAL; |
45083497 | 650 | if (aalg_desc->uinfo.auth.icv_fullbits / 8 != |
38320c70 | 651 | crypto_aead_authsize(aead)) { |
45083497 JP |
652 | pr_info("ESP: %s digestsize %u != %hu\n", |
653 | x->aalg->alg_name, | |
654 | crypto_aead_authsize(aead), | |
655 | aalg_desc->uinfo.auth.icv_fullbits / 8); | |
38320c70 | 656 | goto free_key; |
1da177e4 LT |
657 | } |
658 | ||
38320c70 | 659 | err = crypto_aead_setauthsize( |
8f8a088c | 660 | aead, x->aalg->alg_trunc_len / 8); |
38320c70 HX |
661 | if (err) |
662 | goto free_key; | |
1da177e4 | 663 | } |
4b7137ff | 664 | |
38320c70 HX |
665 | param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); |
666 | memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); | |
667 | ||
668 | err = crypto_aead_setkey(aead, key, keylen); | |
669 | ||
670 | free_key: | |
671 | kfree(key); | |
672 | ||
1a6509d9 HX |
673 | error: |
674 | return err; | |
675 | } | |
676 | ||
677 | static int esp_init_state(struct xfrm_state *x) | |
678 | { | |
1a6509d9 HX |
679 | struct crypto_aead *aead; |
680 | u32 align; | |
681 | int err; | |
682 | ||
1c5ad13f | 683 | x->data = NULL; |
1a6509d9 HX |
684 | |
685 | if (x->aead) | |
686 | err = esp_init_aead(x); | |
687 | else | |
688 | err = esp_init_authenc(x); | |
689 | ||
38320c70 | 690 | if (err) |
1da177e4 | 691 | goto error; |
38320c70 | 692 | |
1c5ad13f | 693 | aead = x->data; |
1a6509d9 | 694 | |
38320c70 HX |
695 | x->props.header_len = sizeof(struct ip_esp_hdr) + |
696 | crypto_aead_ivsize(aead); | |
7e49e6de | 697 | if (x->props.mode == XFRM_MODE_TUNNEL) |
1da177e4 | 698 | x->props.header_len += sizeof(struct iphdr); |
eb49e630 | 699 | else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) |
ac758e3c | 700 | x->props.header_len += IPV4_BEET_PHMAXLEN; |
1da177e4 LT |
701 | if (x->encap) { |
702 | struct xfrm_encap_tmpl *encap = x->encap; | |
703 | ||
704 | switch (encap->encap_type) { | |
705 | default: | |
706 | goto error; | |
707 | case UDP_ENCAP_ESPINUDP: | |
708 | x->props.header_len += sizeof(struct udphdr); | |
709 | break; | |
710 | case UDP_ENCAP_ESPINUDP_NON_IKE: | |
711 | x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); | |
712 | break; | |
713 | } | |
714 | } | |
38320c70 HX |
715 | |
716 | align = ALIGN(crypto_aead_blocksize(aead), 4); | |
1c5ad13f | 717 | x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); |
1da177e4 LT |
718 | |
719 | error: | |
38320c70 | 720 | return err; |
1da177e4 LT |
721 | } |
722 | ||
827789cb SK |
723 | static int esp4_rcv_cb(struct sk_buff *skb, int err) |
724 | { | |
725 | return 0; | |
726 | } | |
727 | ||
533cb5b0 | 728 | static const struct xfrm_type esp_type = |
1da177e4 LT |
729 | { |
730 | .description = "ESP4", | |
731 | .owner = THIS_MODULE, | |
732 | .proto = IPPROTO_ESP, | |
436a0a40 | 733 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
734 | .init_state = esp_init_state, |
735 | .destructor = esp_destroy, | |
c5c25238 | 736 | .get_mtu = esp4_get_mtu, |
1da177e4 | 737 | .input = esp_input, |
1da177e4 LT |
738 | .output = esp_output |
739 | }; | |
740 | ||
827789cb | 741 | static struct xfrm4_protocol esp4_protocol = { |
1da177e4 | 742 | .handler = xfrm4_rcv, |
827789cb SK |
743 | .input_handler = xfrm_input, |
744 | .cb_handler = esp4_rcv_cb, | |
1da177e4 | 745 | .err_handler = esp4_err, |
827789cb | 746 | .priority = 0, |
1da177e4 LT |
747 | }; |
748 | ||
749 | static int __init esp4_init(void) | |
750 | { | |
1da177e4 | 751 | if (xfrm_register_type(&esp_type, AF_INET) < 0) { |
058bd4d2 | 752 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
753 | return -EAGAIN; |
754 | } | |
827789cb | 755 | if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { |
058bd4d2 | 756 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
757 | xfrm_unregister_type(&esp_type, AF_INET); |
758 | return -EAGAIN; | |
759 | } | |
760 | return 0; | |
761 | } | |
762 | ||
763 | static void __exit esp4_fini(void) | |
764 | { | |
827789cb | 765 | if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) |
058bd4d2 | 766 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 | 767 | if (xfrm_unregister_type(&esp_type, AF_INET) < 0) |
058bd4d2 | 768 | pr_info("%s: can't remove xfrm type\n", __func__); |
1da177e4 LT |
769 | } |
770 | ||
771 | module_init(esp4_init); | |
772 | module_exit(esp4_fini); | |
773 | MODULE_LICENSE("GPL"); | |
d3d6dd3a | 774 | MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); |