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Commit | Line | Data |
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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 | ||
cac2661c SK |
21 | #include <linux/highmem.h> |
22 | ||
38320c70 HX |
23 | struct esp_skb_cb { |
24 | struct xfrm_skb_cb xfrm; | |
25 | void *tmp; | |
26 | }; | |
27 | ||
962fcef3 HX |
28 | struct esp_output_extra { |
29 | __be32 seqhi; | |
30 | u32 esphoff; | |
31 | }; | |
32 | ||
38320c70 HX |
33 | #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) |
34 | ||
d979e20f MW |
35 | static u32 esp4_get_mtu(struct xfrm_state *x, int mtu); |
36 | ||
38320c70 HX |
37 | /* |
38 | * Allocate an AEAD request structure with extra space for SG and IV. | |
39 | * | |
40 | * For alignment considerations the IV is placed at the front, followed | |
41 | * by the request and finally the SG list. | |
42 | * | |
43 | * TODO: Use spare space in skb for this where possible. | |
44 | */ | |
962fcef3 | 45 | static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen) |
38320c70 HX |
46 | { |
47 | unsigned int len; | |
48 | ||
962fcef3 | 49 | len = extralen; |
0dc49e9b SK |
50 | |
51 | len += crypto_aead_ivsize(aead); | |
52 | ||
38320c70 HX |
53 | if (len) { |
54 | len += crypto_aead_alignmask(aead) & | |
55 | ~(crypto_tfm_ctx_alignment() - 1); | |
56 | len = ALIGN(len, crypto_tfm_ctx_alignment()); | |
57 | } | |
58 | ||
7021b2e1 | 59 | len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); |
38320c70 HX |
60 | len = ALIGN(len, __alignof__(struct scatterlist)); |
61 | ||
62 | len += sizeof(struct scatterlist) * nfrags; | |
63 | ||
64 | return kmalloc(len, GFP_ATOMIC); | |
65 | } | |
66 | ||
962fcef3 | 67 | static inline void *esp_tmp_extra(void *tmp) |
0dc49e9b | 68 | { |
962fcef3 | 69 | return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra)); |
0dc49e9b | 70 | } |
962fcef3 HX |
71 | |
72 | static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen) | |
38320c70 HX |
73 | { |
74 | return crypto_aead_ivsize(aead) ? | |
962fcef3 HX |
75 | PTR_ALIGN((u8 *)tmp + extralen, |
76 | crypto_aead_alignmask(aead) + 1) : tmp + extralen; | |
38320c70 HX |
77 | } |
78 | ||
38320c70 HX |
79 | static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) |
80 | { | |
81 | struct aead_request *req; | |
82 | ||
83 | req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), | |
84 | crypto_tfm_ctx_alignment()); | |
85 | aead_request_set_tfm(req, aead); | |
86 | return req; | |
87 | } | |
88 | ||
89 | static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, | |
90 | struct aead_request *req) | |
91 | { | |
92 | return (void *)ALIGN((unsigned long)(req + 1) + | |
93 | crypto_aead_reqsize(aead), | |
94 | __alignof__(struct scatterlist)); | |
95 | } | |
96 | ||
cac2661c SK |
97 | static void esp_ssg_unref(struct xfrm_state *x, void *tmp) |
98 | { | |
99 | struct esp_output_extra *extra = esp_tmp_extra(tmp); | |
100 | struct crypto_aead *aead = x->data; | |
101 | int extralen = 0; | |
102 | u8 *iv; | |
103 | struct aead_request *req; | |
104 | struct scatterlist *sg; | |
105 | ||
106 | if (x->props.flags & XFRM_STATE_ESN) | |
107 | extralen += sizeof(*extra); | |
108 | ||
109 | extra = esp_tmp_extra(tmp); | |
110 | iv = esp_tmp_iv(aead, tmp, extralen); | |
111 | req = esp_tmp_req(aead, iv); | |
112 | ||
113 | /* Unref skb_frag_pages in the src scatterlist if necessary. | |
114 | * Skip the first sg which comes from skb->data. | |
115 | */ | |
116 | if (req->src != req->dst) | |
117 | for (sg = sg_next(req->src); sg; sg = sg_next(sg)) | |
118 | put_page(sg_page(sg)); | |
119 | } | |
120 | ||
38320c70 HX |
121 | static void esp_output_done(struct crypto_async_request *base, int err) |
122 | { | |
123 | struct sk_buff *skb = base->data; | |
cac2661c SK |
124 | void *tmp; |
125 | struct dst_entry *dst = skb_dst(skb); | |
126 | struct xfrm_state *x = dst->xfrm; | |
38320c70 | 127 | |
cac2661c SK |
128 | tmp = ESP_SKB_CB(skb)->tmp; |
129 | esp_ssg_unref(x, tmp); | |
130 | kfree(tmp); | |
38320c70 HX |
131 | xfrm_output_resume(skb, err); |
132 | } | |
133 | ||
7021b2e1 HX |
134 | /* Move ESP header back into place. */ |
135 | static void esp_restore_header(struct sk_buff *skb, unsigned int offset) | |
136 | { | |
137 | struct ip_esp_hdr *esph = (void *)(skb->data + offset); | |
138 | void *tmp = ESP_SKB_CB(skb)->tmp; | |
962fcef3 | 139 | __be32 *seqhi = esp_tmp_extra(tmp); |
7021b2e1 HX |
140 | |
141 | esph->seq_no = esph->spi; | |
142 | esph->spi = *seqhi; | |
143 | } | |
144 | ||
145 | static void esp_output_restore_header(struct sk_buff *skb) | |
146 | { | |
962fcef3 HX |
147 | void *tmp = ESP_SKB_CB(skb)->tmp; |
148 | struct esp_output_extra *extra = esp_tmp_extra(tmp); | |
149 | ||
150 | esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff - | |
151 | sizeof(__be32)); | |
7021b2e1 HX |
152 | } |
153 | ||
cac2661c | 154 | static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb, |
fca11ebd | 155 | struct xfrm_state *x, |
cac2661c SK |
156 | struct ip_esp_hdr *esph, |
157 | struct esp_output_extra *extra) | |
158 | { | |
cac2661c SK |
159 | /* For ESN we move the header forward by 4 bytes to |
160 | * accomodate the high bits. We will move it back after | |
161 | * encryption. | |
162 | */ | |
163 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
7862b405 SK |
164 | __u32 seqhi; |
165 | struct xfrm_offload *xo = xfrm_offload(skb); | |
166 | ||
167 | if (xo) | |
168 | seqhi = xo->seq.hi; | |
169 | else | |
170 | seqhi = XFRM_SKB_CB(skb)->seq.output.hi; | |
171 | ||
cac2661c SK |
172 | extra->esphoff = (unsigned char *)esph - |
173 | skb_transport_header(skb); | |
174 | esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4); | |
175 | extra->seqhi = esph->spi; | |
7862b405 | 176 | esph->seq_no = htonl(seqhi); |
cac2661c SK |
177 | } |
178 | ||
179 | esph->spi = x->id.spi; | |
180 | ||
181 | return esph; | |
182 | } | |
183 | ||
7021b2e1 HX |
184 | static void esp_output_done_esn(struct crypto_async_request *base, int err) |
185 | { | |
186 | struct sk_buff *skb = base->data; | |
187 | ||
188 | esp_output_restore_header(skb); | |
189 | esp_output_done(base, err); | |
190 | } | |
191 | ||
eb758c88 SK |
192 | static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) |
193 | { | |
194 | /* Fill padding... */ | |
195 | if (tfclen) { | |
196 | memset(tail, 0, tfclen); | |
197 | tail += tfclen; | |
198 | } | |
199 | do { | |
200 | int i; | |
201 | for (i = 0; i < plen - 2; i++) | |
202 | tail[i] = i + 1; | |
203 | } while (0); | |
204 | tail[plen - 2] = plen - 2; | |
205 | tail[plen - 1] = proto; | |
206 | } | |
207 | ||
fca11ebd | 208 | static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) |
1da177e4 | 209 | { |
fca11ebd SK |
210 | int encap_type; |
211 | struct udphdr *uh; | |
212 | __be32 *udpdata32; | |
213 | __be16 sport, dport; | |
214 | struct xfrm_encap_tmpl *encap = x->encap; | |
215 | struct ip_esp_hdr *esph = esp->esph; | |
216 | ||
217 | spin_lock_bh(&x->lock); | |
218 | sport = encap->encap_sport; | |
219 | dport = encap->encap_dport; | |
220 | encap_type = encap->encap_type; | |
221 | spin_unlock_bh(&x->lock); | |
222 | ||
223 | uh = (struct udphdr *)esph; | |
224 | uh->source = sport; | |
225 | uh->dest = dport; | |
226 | uh->len = htons(skb->len + esp->tailen | |
227 | - skb_transport_offset(skb)); | |
228 | uh->check = 0; | |
229 | ||
230 | switch (encap_type) { | |
231 | default: | |
232 | case UDP_ENCAP_ESPINUDP: | |
233 | esph = (struct ip_esp_hdr *)(uh + 1); | |
234 | break; | |
235 | case UDP_ENCAP_ESPINUDP_NON_IKE: | |
236 | udpdata32 = (__be32 *)(uh + 1); | |
237 | udpdata32[0] = udpdata32[1] = 0; | |
238 | esph = (struct ip_esp_hdr *)(udpdata32 + 2); | |
239 | break; | |
d979e20f | 240 | } |
0dc49e9b | 241 | |
fca11ebd SK |
242 | *skb_mac_header(skb) = IPPROTO_UDP; |
243 | esp->esph = esph; | |
244 | } | |
0dc49e9b | 245 | |
fca11ebd SK |
246 | int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) |
247 | { | |
248 | u8 *tail; | |
249 | u8 *vaddr; | |
250 | int nfrags; | |
0e78a873 | 251 | int esph_offset; |
fca11ebd SK |
252 | struct page *page; |
253 | struct sk_buff *trailer; | |
254 | int tailen = esp->tailen; | |
1da177e4 LT |
255 | |
256 | /* this is non-NULL only with UDP Encapsulation */ | |
fca11ebd SK |
257 | if (x->encap) |
258 | esp_output_udp_encap(x, skb, esp); | |
1da177e4 | 259 | |
cac2661c SK |
260 | if (!skb_cloned(skb)) { |
261 | if (tailen <= skb_availroom(skb)) { | |
262 | nfrags = 1; | |
263 | trailer = skb; | |
264 | tail = skb_tail_pointer(trailer); | |
1da177e4 | 265 | |
cac2661c SK |
266 | goto skip_cow; |
267 | } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) | |
268 | && !skb_has_frag_list(skb)) { | |
269 | int allocsize; | |
270 | struct sock *sk = skb->sk; | |
271 | struct page_frag *pfrag = &x->xfrag; | |
7021b2e1 | 272 | |
fca11ebd SK |
273 | esp->inplace = false; |
274 | ||
cac2661c SK |
275 | allocsize = ALIGN(tailen, L1_CACHE_BYTES); |
276 | ||
277 | spin_lock_bh(&x->lock); | |
278 | ||
279 | if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { | |
280 | spin_unlock_bh(&x->lock); | |
281 | goto cow; | |
282 | } | |
283 | ||
284 | page = pfrag->page; | |
285 | get_page(page); | |
286 | ||
287 | vaddr = kmap_atomic(page); | |
288 | ||
289 | tail = vaddr + pfrag->offset; | |
290 | ||
fca11ebd | 291 | esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); |
cac2661c SK |
292 | |
293 | kunmap_atomic(vaddr); | |
294 | ||
fca11ebd SK |
295 | spin_unlock_bh(&x->lock); |
296 | ||
cac2661c SK |
297 | nfrags = skb_shinfo(skb)->nr_frags; |
298 | ||
299 | __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, | |
300 | tailen); | |
301 | skb_shinfo(skb)->nr_frags = ++nfrags; | |
302 | ||
303 | pfrag->offset = pfrag->offset + allocsize; | |
304 | nfrags++; | |
305 | ||
306 | skb->len += tailen; | |
307 | skb->data_len += tailen; | |
308 | skb->truesize += tailen; | |
309 | if (sk) | |
310 | atomic_add(tailen, &sk->sk_wmem_alloc); | |
311 | ||
fca11ebd | 312 | goto out; |
cac2661c | 313 | } |
7021b2e1 HX |
314 | } |
315 | ||
cac2661c | 316 | cow: |
0e78a873 SK |
317 | esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb); |
318 | ||
fca11ebd SK |
319 | nfrags = skb_cow_data(skb, tailen, &trailer); |
320 | if (nfrags < 0) | |
321 | goto out; | |
cac2661c | 322 | tail = skb_tail_pointer(trailer); |
0e78a873 | 323 | esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset); |
cac2661c SK |
324 | |
325 | skip_cow: | |
fca11ebd SK |
326 | esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); |
327 | pskb_put(skb, trailer, tailen); | |
cac2661c | 328 | |
fca11ebd SK |
329 | out: |
330 | return nfrags; | |
331 | } | |
332 | EXPORT_SYMBOL_GPL(esp_output_head); | |
333 | ||
334 | int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) | |
335 | { | |
336 | u8 *iv; | |
337 | int alen; | |
338 | void *tmp; | |
339 | int ivlen; | |
340 | int assoclen; | |
341 | int extralen; | |
342 | struct page *page; | |
343 | struct ip_esp_hdr *esph; | |
344 | struct crypto_aead *aead; | |
345 | struct aead_request *req; | |
346 | struct scatterlist *sg, *dsg; | |
347 | struct esp_output_extra *extra; | |
348 | int err = -ENOMEM; | |
349 | ||
350 | assoclen = sizeof(struct ip_esp_hdr); | |
351 | extralen = 0; | |
352 | ||
353 | if (x->props.flags & XFRM_STATE_ESN) { | |
354 | extralen += sizeof(*extra); | |
355 | assoclen += sizeof(__be32); | |
356 | } | |
7021b2e1 | 357 | |
fca11ebd SK |
358 | aead = x->data; |
359 | alen = crypto_aead_authsize(aead); | |
360 | ivlen = crypto_aead_ivsize(aead); | |
361 | ||
362 | tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen); | |
e892d2d4 | 363 | if (!tmp) |
cac2661c | 364 | goto error; |
cac2661c SK |
365 | |
366 | extra = esp_tmp_extra(tmp); | |
367 | iv = esp_tmp_iv(aead, tmp, extralen); | |
368 | req = esp_tmp_req(aead, iv); | |
369 | sg = esp_req_sg(aead, req); | |
cac2661c | 370 | |
fca11ebd SK |
371 | if (esp->inplace) |
372 | dsg = sg; | |
373 | else | |
374 | dsg = &sg[esp->nfrags]; | |
cac2661c | 375 | |
fca11ebd SK |
376 | esph = esp_output_set_extra(skb, x, esp->esph, extra); |
377 | esp->esph = esph; | |
378 | ||
379 | sg_init_table(sg, esp->nfrags); | |
38320c70 | 380 | skb_to_sgvec(skb, sg, |
7021b2e1 | 381 | (unsigned char *)esph - skb->data, |
fca11ebd SK |
382 | assoclen + ivlen + esp->clen + alen); |
383 | ||
384 | if (!esp->inplace) { | |
385 | int allocsize; | |
386 | struct page_frag *pfrag = &x->xfrag; | |
387 | ||
388 | allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); | |
389 | ||
390 | spin_lock_bh(&x->lock); | |
391 | if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { | |
392 | spin_unlock_bh(&x->lock); | |
fca11ebd SK |
393 | goto error; |
394 | } | |
395 | ||
396 | skb_shinfo(skb)->nr_frags = 1; | |
397 | ||
398 | page = pfrag->page; | |
399 | get_page(page); | |
400 | /* replace page frags in skb with new page */ | |
401 | __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); | |
402 | pfrag->offset = pfrag->offset + allocsize; | |
403 | spin_unlock_bh(&x->lock); | |
404 | ||
405 | sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); | |
406 | skb_to_sgvec(skb, dsg, | |
407 | (unsigned char *)esph - skb->data, | |
408 | assoclen + ivlen + esp->clen + alen); | |
409 | } | |
0dc49e9b | 410 | |
cac2661c SK |
411 | if ((x->props.flags & XFRM_STATE_ESN)) |
412 | aead_request_set_callback(req, 0, esp_output_done_esn, skb); | |
413 | else | |
414 | aead_request_set_callback(req, 0, esp_output_done, skb); | |
415 | ||
fca11ebd | 416 | aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); |
7021b2e1 HX |
417 | aead_request_set_ad(req, assoclen); |
418 | ||
7021b2e1 | 419 | memset(iv, 0, ivlen); |
fca11ebd | 420 | memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), |
7021b2e1 | 421 | min(ivlen, 8)); |
38320c70 HX |
422 | |
423 | ESP_SKB_CB(skb)->tmp = tmp; | |
7021b2e1 HX |
424 | err = crypto_aead_encrypt(req); |
425 | ||
426 | switch (err) { | |
427 | case -EINPROGRESS: | |
38320c70 | 428 | goto error; |
1da177e4 | 429 | |
7021b2e1 | 430 | case -EBUSY: |
38320c70 | 431 | err = NET_XMIT_DROP; |
7021b2e1 HX |
432 | break; |
433 | ||
434 | case 0: | |
435 | if ((x->props.flags & XFRM_STATE_ESN)) | |
436 | esp_output_restore_header(skb); | |
437 | } | |
1da177e4 | 438 | |
cac2661c SK |
439 | if (sg != dsg) |
440 | esp_ssg_unref(x, tmp); | |
38320c70 | 441 | kfree(tmp); |
b7c6538c | 442 | |
1da177e4 LT |
443 | error: |
444 | return err; | |
445 | } | |
fca11ebd SK |
446 | EXPORT_SYMBOL_GPL(esp_output_tail); |
447 | ||
448 | static int esp_output(struct xfrm_state *x, struct sk_buff *skb) | |
449 | { | |
450 | int alen; | |
451 | int blksize; | |
452 | struct ip_esp_hdr *esph; | |
453 | struct crypto_aead *aead; | |
454 | struct esp_info esp; | |
455 | ||
456 | esp.inplace = true; | |
457 | ||
458 | esp.proto = *skb_mac_header(skb); | |
459 | *skb_mac_header(skb) = IPPROTO_ESP; | |
460 | ||
461 | /* skb is pure payload to encrypt */ | |
462 | ||
463 | aead = x->data; | |
464 | alen = crypto_aead_authsize(aead); | |
465 | ||
466 | esp.tfclen = 0; | |
467 | if (x->tfcpad) { | |
468 | struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); | |
469 | u32 padto; | |
470 | ||
471 | padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached)); | |
472 | if (skb->len < padto) | |
473 | esp.tfclen = padto - skb->len; | |
474 | } | |
475 | blksize = ALIGN(crypto_aead_blocksize(aead), 4); | |
476 | esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); | |
477 | esp.plen = esp.clen - skb->len - esp.tfclen; | |
478 | esp.tailen = esp.tfclen + esp.plen + alen; | |
479 | ||
480 | esp.esph = ip_esp_hdr(skb); | |
481 | ||
482 | esp.nfrags = esp_output_head(x, skb, &esp); | |
483 | if (esp.nfrags < 0) | |
484 | return esp.nfrags; | |
485 | ||
486 | esph = esp.esph; | |
487 | esph->spi = x->id.spi; | |
488 | ||
489 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); | |
490 | esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + | |
491 | ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); | |
492 | ||
493 | skb_push(skb, -skb_network_offset(skb)); | |
494 | ||
495 | return esp_output_tail(x, skb, &esp); | |
496 | } | |
1da177e4 | 497 | |
fca11ebd | 498 | int esp_input_done2(struct sk_buff *skb, int err) |
1da177e4 | 499 | { |
b71d1d42 | 500 | const struct iphdr *iph; |
38320c70 | 501 | struct xfrm_state *x = xfrm_input_state(skb); |
d77e38e6 | 502 | struct xfrm_offload *xo = xfrm_offload(skb); |
1c5ad13f | 503 | struct crypto_aead *aead = x->data; |
38320c70 HX |
504 | int alen = crypto_aead_authsize(aead); |
505 | int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); | |
506 | int elen = skb->len - hlen; | |
31a4ab93 | 507 | int ihl; |
4bf05ece | 508 | u8 nexthdr[2]; |
4bf05ece | 509 | int padlen; |
1da177e4 | 510 | |
d77e38e6 SK |
511 | if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) |
512 | kfree(ESP_SKB_CB(skb)->tmp); | |
0ebea8ef | 513 | |
6b7326c8 | 514 | if (unlikely(err)) |
668dc8af | 515 | goto out; |
1da177e4 | 516 | |
4bf05ece HX |
517 | if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2)) |
518 | BUG(); | |
1da177e4 | 519 | |
668dc8af | 520 | err = -EINVAL; |
4bf05ece | 521 | padlen = nexthdr[0]; |
38320c70 | 522 | if (padlen + 2 + alen >= elen) |
4bf05ece | 523 | goto out; |
1da177e4 | 524 | |
e905a9ed | 525 | /* ... check padding bits here. Silly. :-) */ |
1da177e4 | 526 | |
eddc9ec5 | 527 | iph = ip_hdr(skb); |
31a4ab93 HX |
528 | ihl = iph->ihl * 4; |
529 | ||
752c1f4c HX |
530 | if (x->encap) { |
531 | struct xfrm_encap_tmpl *encap = x->encap; | |
d56f90a7 | 532 | struct udphdr *uh = (void *)(skb_network_header(skb) + ihl); |
752c1f4c HX |
533 | |
534 | /* | |
535 | * 1) if the NAT-T peer's IP or port changed then | |
536 | * advertize the change to the keying daemon. | |
537 | * This is an inbound SA, so just compare | |
538 | * SRC ports. | |
539 | */ | |
540 | if (iph->saddr != x->props.saddr.a4 || | |
541 | uh->source != encap->encap_sport) { | |
542 | xfrm_address_t ipaddr; | |
543 | ||
544 | ipaddr.a4 = iph->saddr; | |
545 | km_new_mapping(x, &ipaddr, uh->source); | |
e905a9ed | 546 | |
752c1f4c HX |
547 | /* XXX: perhaps add an extra |
548 | * policy check here, to see | |
549 | * if we should allow or | |
550 | * reject a packet from a | |
551 | * different source | |
552 | * address/port. | |
553 | */ | |
1da177e4 | 554 | } |
e905a9ed | 555 | |
752c1f4c HX |
556 | /* |
557 | * 2) ignore UDP/TCP checksums in case | |
558 | * of NAT-T in Transport Mode, or | |
559 | * perform other post-processing fixes | |
560 | * as per draft-ietf-ipsec-udp-encaps-06, | |
561 | * section 3.1.2 | |
562 | */ | |
8bd17075 | 563 | if (x->props.mode == XFRM_MODE_TRANSPORT) |
752c1f4c | 564 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
1da177e4 LT |
565 | } |
566 | ||
4bf05ece | 567 | pskb_trim(skb, skb->len - alen - padlen - 2); |
38320c70 | 568 | __skb_pull(skb, hlen); |
7143dfac LR |
569 | if (x->props.mode == XFRM_MODE_TUNNEL) |
570 | skb_reset_transport_header(skb); | |
571 | else | |
572 | skb_set_transport_header(skb, -ihl); | |
4bf05ece | 573 | |
38320c70 HX |
574 | err = nexthdr[1]; |
575 | ||
576 | /* RFC4303: Drop dummy packets without any error */ | |
577 | if (err == IPPROTO_NONE) | |
578 | err = -EINVAL; | |
579 | ||
580 | out: | |
581 | return err; | |
582 | } | |
fca11ebd | 583 | EXPORT_SYMBOL_GPL(esp_input_done2); |
38320c70 HX |
584 | |
585 | static void esp_input_done(struct crypto_async_request *base, int err) | |
586 | { | |
587 | struct sk_buff *skb = base->data; | |
588 | ||
589 | xfrm_input_resume(skb, esp_input_done2(skb, err)); | |
590 | } | |
591 | ||
7021b2e1 HX |
592 | static void esp_input_restore_header(struct sk_buff *skb) |
593 | { | |
594 | esp_restore_header(skb, 0); | |
595 | __skb_pull(skb, 4); | |
596 | } | |
597 | ||
cac2661c SK |
598 | static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) |
599 | { | |
600 | struct xfrm_state *x = xfrm_input_state(skb); | |
601 | struct ip_esp_hdr *esph = (struct ip_esp_hdr *)skb->data; | |
602 | ||
603 | /* For ESN we move the header forward by 4 bytes to | |
604 | * accomodate the high bits. We will move it back after | |
605 | * decryption. | |
606 | */ | |
607 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
608 | esph = (void *)skb_push(skb, 4); | |
609 | *seqhi = esph->spi; | |
610 | esph->spi = esph->seq_no; | |
611 | esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; | |
612 | } | |
613 | } | |
614 | ||
7021b2e1 HX |
615 | static void esp_input_done_esn(struct crypto_async_request *base, int err) |
616 | { | |
617 | struct sk_buff *skb = base->data; | |
618 | ||
619 | esp_input_restore_header(skb); | |
620 | esp_input_done(base, err); | |
621 | } | |
622 | ||
38320c70 HX |
623 | /* |
624 | * Note: detecting truncated vs. non-truncated authentication data is very | |
625 | * expensive, so we only support truncated data, which is the recommended | |
626 | * and common case. | |
627 | */ | |
628 | static int esp_input(struct xfrm_state *x, struct sk_buff *skb) | |
629 | { | |
630 | struct ip_esp_hdr *esph; | |
1c5ad13f | 631 | struct crypto_aead *aead = x->data; |
38320c70 HX |
632 | struct aead_request *req; |
633 | struct sk_buff *trailer; | |
7021b2e1 HX |
634 | int ivlen = crypto_aead_ivsize(aead); |
635 | int elen = skb->len - sizeof(*esph) - ivlen; | |
38320c70 | 636 | int nfrags; |
0dc49e9b | 637 | int assoclen; |
0dc49e9b SK |
638 | int seqhilen; |
639 | __be32 *seqhi; | |
38320c70 HX |
640 | void *tmp; |
641 | u8 *iv; | |
642 | struct scatterlist *sg; | |
38320c70 HX |
643 | int err = -EINVAL; |
644 | ||
7021b2e1 | 645 | if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) |
38320c70 HX |
646 | goto out; |
647 | ||
648 | if (elen <= 0) | |
649 | goto out; | |
650 | ||
0dc49e9b | 651 | assoclen = sizeof(*esph); |
0dc49e9b SK |
652 | seqhilen = 0; |
653 | ||
654 | if (x->props.flags & XFRM_STATE_ESN) { | |
0dc49e9b SK |
655 | seqhilen += sizeof(__be32); |
656 | assoclen += seqhilen; | |
657 | } | |
658 | ||
cac2661c SK |
659 | if (!skb_cloned(skb)) { |
660 | if (!skb_is_nonlinear(skb)) { | |
661 | nfrags = 1; | |
662 | ||
663 | goto skip_cow; | |
664 | } else if (!skb_has_frag_list(skb)) { | |
665 | nfrags = skb_shinfo(skb)->nr_frags; | |
666 | nfrags++; | |
667 | ||
668 | goto skip_cow; | |
669 | } | |
670 | } | |
671 | ||
672 | err = skb_cow_data(skb, 0, &trailer); | |
673 | if (err < 0) | |
674 | goto out; | |
675 | ||
676 | nfrags = err; | |
677 | ||
678 | skip_cow: | |
38320c70 | 679 | err = -ENOMEM; |
7021b2e1 | 680 | tmp = esp_alloc_tmp(aead, nfrags, seqhilen); |
38320c70 HX |
681 | if (!tmp) |
682 | goto out; | |
683 | ||
684 | ESP_SKB_CB(skb)->tmp = tmp; | |
962fcef3 | 685 | seqhi = esp_tmp_extra(tmp); |
0dc49e9b | 686 | iv = esp_tmp_iv(aead, tmp, seqhilen); |
38320c70 | 687 | req = esp_tmp_req(aead, iv); |
7021b2e1 | 688 | sg = esp_req_sg(aead, req); |
38320c70 | 689 | |
cac2661c | 690 | esp_input_set_header(skb, seqhi); |
38320c70 | 691 | |
cac2661c SK |
692 | sg_init_table(sg, nfrags); |
693 | skb_to_sgvec(skb, sg, 0, skb->len); | |
38320c70 | 694 | |
cac2661c | 695 | skb->ip_summed = CHECKSUM_NONE; |
0dc49e9b | 696 | |
cac2661c | 697 | if ((x->props.flags & XFRM_STATE_ESN)) |
7021b2e1 | 698 | aead_request_set_callback(req, 0, esp_input_done_esn, skb); |
cac2661c SK |
699 | else |
700 | aead_request_set_callback(req, 0, esp_input_done, skb); | |
7021b2e1 HX |
701 | |
702 | aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); | |
703 | aead_request_set_ad(req, assoclen); | |
38320c70 HX |
704 | |
705 | err = crypto_aead_decrypt(req); | |
706 | if (err == -EINPROGRESS) | |
707 | goto out; | |
708 | ||
7021b2e1 HX |
709 | if ((x->props.flags & XFRM_STATE_ESN)) |
710 | esp_input_restore_header(skb); | |
711 | ||
38320c70 | 712 | err = esp_input_done2(skb, err); |
1da177e4 LT |
713 | |
714 | out: | |
668dc8af | 715 | return err; |
1da177e4 LT |
716 | } |
717 | ||
c5c25238 | 718 | static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) |
1da177e4 | 719 | { |
1c5ad13f MK |
720 | struct crypto_aead *aead = x->data; |
721 | u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); | |
91657eaf | 722 | unsigned int net_adj; |
0a69452c DB |
723 | |
724 | switch (x->props.mode) { | |
0a69452c | 725 | case XFRM_MODE_TRANSPORT: |
0a69452c | 726 | case XFRM_MODE_BEET: |
91657eaf | 727 | net_adj = sizeof(struct iphdr); |
0a69452c | 728 | break; |
91657eaf BP |
729 | case XFRM_MODE_TUNNEL: |
730 | net_adj = 0; | |
731 | break; | |
732 | default: | |
733 | BUG(); | |
1da177e4 | 734 | } |
0a69452c | 735 | |
1c5ad13f | 736 | return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - |
123b0d1b | 737 | net_adj) & ~(blksize - 1)) + net_adj - 2; |
1da177e4 LT |
738 | } |
739 | ||
827789cb | 740 | static int esp4_err(struct sk_buff *skb, u32 info) |
1da177e4 | 741 | { |
4fb236ba | 742 | struct net *net = dev_net(skb->dev); |
b71d1d42 | 743 | const struct iphdr *iph = (const struct iphdr *)skb->data; |
d9319100 | 744 | struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2)); |
1da177e4 LT |
745 | struct xfrm_state *x; |
746 | ||
55be7a9c DM |
747 | switch (icmp_hdr(skb)->type) { |
748 | case ICMP_DEST_UNREACH: | |
749 | if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED) | |
827789cb | 750 | return 0; |
55be7a9c DM |
751 | case ICMP_REDIRECT: |
752 | break; | |
753 | default: | |
827789cb | 754 | return 0; |
55be7a9c | 755 | } |
1da177e4 | 756 | |
b71d1d42 ED |
757 | x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, |
758 | esph->spi, IPPROTO_ESP, AF_INET); | |
1da177e4 | 759 | if (!x) |
827789cb | 760 | return 0; |
55be7a9c | 761 | |
387aa65a | 762 | if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH) |
55be7a9c | 763 | ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0); |
387aa65a | 764 | else |
55be7a9c | 765 | ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0); |
1da177e4 | 766 | xfrm_state_put(x); |
827789cb SK |
767 | |
768 | return 0; | |
1da177e4 LT |
769 | } |
770 | ||
771 | static void esp_destroy(struct xfrm_state *x) | |
772 | { | |
1c5ad13f | 773 | struct crypto_aead *aead = x->data; |
1da177e4 | 774 | |
1c5ad13f | 775 | if (!aead) |
1da177e4 LT |
776 | return; |
777 | ||
1c5ad13f | 778 | crypto_free_aead(aead); |
1da177e4 LT |
779 | } |
780 | ||
1a6509d9 | 781 | static int esp_init_aead(struct xfrm_state *x) |
1da177e4 | 782 | { |
7021b2e1 | 783 | char aead_name[CRYPTO_MAX_ALG_NAME]; |
1a6509d9 HX |
784 | struct crypto_aead *aead; |
785 | int err; | |
b3859c8e | 786 | u32 mask = 0; |
1a6509d9 | 787 | |
7021b2e1 HX |
788 | err = -ENAMETOOLONG; |
789 | if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", | |
790 | x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) | |
791 | goto error; | |
792 | ||
b3859c8e SK |
793 | if (x->xso.offload_handle) |
794 | mask |= CRYPTO_ALG_ASYNC; | |
795 | ||
796 | aead = crypto_alloc_aead(aead_name, 0, mask); | |
1a6509d9 HX |
797 | err = PTR_ERR(aead); |
798 | if (IS_ERR(aead)) | |
799 | goto error; | |
800 | ||
1c5ad13f | 801 | x->data = aead; |
1a6509d9 HX |
802 | |
803 | err = crypto_aead_setkey(aead, x->aead->alg_key, | |
804 | (x->aead->alg_key_len + 7) / 8); | |
805 | if (err) | |
806 | goto error; | |
807 | ||
808 | err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); | |
809 | if (err) | |
810 | goto error; | |
811 | ||
812 | error: | |
813 | return err; | |
814 | } | |
815 | ||
816 | static int esp_init_authenc(struct xfrm_state *x) | |
817 | { | |
38320c70 HX |
818 | struct crypto_aead *aead; |
819 | struct crypto_authenc_key_param *param; | |
820 | struct rtattr *rta; | |
821 | char *key; | |
822 | char *p; | |
823 | char authenc_name[CRYPTO_MAX_ALG_NAME]; | |
38320c70 HX |
824 | unsigned int keylen; |
825 | int err; | |
b3859c8e | 826 | u32 mask = 0; |
1da177e4 | 827 | |
1a6509d9 | 828 | err = -EINVAL; |
51456b29 | 829 | if (!x->ealg) |
1a6509d9 | 830 | goto error; |
38320c70 | 831 | |
1a6509d9 | 832 | err = -ENAMETOOLONG; |
0dc49e9b SK |
833 | |
834 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
835 | if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, | |
7021b2e1 HX |
836 | "%s%sauthencesn(%s,%s)%s", |
837 | x->geniv ?: "", x->geniv ? "(" : "", | |
0dc49e9b | 838 | x->aalg ? x->aalg->alg_name : "digest_null", |
7021b2e1 HX |
839 | x->ealg->alg_name, |
840 | x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) | |
0dc49e9b SK |
841 | goto error; |
842 | } else { | |
843 | if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, | |
7021b2e1 HX |
844 | "%s%sauthenc(%s,%s)%s", |
845 | x->geniv ?: "", x->geniv ? "(" : "", | |
0dc49e9b | 846 | x->aalg ? x->aalg->alg_name : "digest_null", |
7021b2e1 HX |
847 | x->ealg->alg_name, |
848 | x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) | |
0dc49e9b SK |
849 | goto error; |
850 | } | |
38320c70 | 851 | |
b3859c8e SK |
852 | if (x->xso.offload_handle) |
853 | mask |= CRYPTO_ALG_ASYNC; | |
854 | ||
855 | aead = crypto_alloc_aead(authenc_name, 0, mask); | |
38320c70 HX |
856 | err = PTR_ERR(aead); |
857 | if (IS_ERR(aead)) | |
858 | goto error; | |
859 | ||
1c5ad13f | 860 | x->data = aead; |
38320c70 HX |
861 | |
862 | keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + | |
863 | (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); | |
864 | err = -ENOMEM; | |
865 | key = kmalloc(keylen, GFP_KERNEL); | |
866 | if (!key) | |
867 | goto error; | |
868 | ||
869 | p = key; | |
870 | rta = (void *)p; | |
871 | rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; | |
872 | rta->rta_len = RTA_LENGTH(sizeof(*param)); | |
873 | param = RTA_DATA(rta); | |
874 | p += RTA_SPACE(sizeof(*param)); | |
875 | ||
1da177e4 LT |
876 | if (x->aalg) { |
877 | struct xfrm_algo_desc *aalg_desc; | |
878 | ||
38320c70 HX |
879 | memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); |
880 | p += (x->aalg->alg_key_len + 7) / 8; | |
1da177e4 LT |
881 | |
882 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
883 | BUG_ON(!aalg_desc); | |
884 | ||
38320c70 | 885 | err = -EINVAL; |
45083497 | 886 | if (aalg_desc->uinfo.auth.icv_fullbits / 8 != |
38320c70 | 887 | crypto_aead_authsize(aead)) { |
45083497 JP |
888 | pr_info("ESP: %s digestsize %u != %hu\n", |
889 | x->aalg->alg_name, | |
890 | crypto_aead_authsize(aead), | |
891 | aalg_desc->uinfo.auth.icv_fullbits / 8); | |
38320c70 | 892 | goto free_key; |
1da177e4 LT |
893 | } |
894 | ||
38320c70 | 895 | err = crypto_aead_setauthsize( |
8f8a088c | 896 | aead, x->aalg->alg_trunc_len / 8); |
38320c70 HX |
897 | if (err) |
898 | goto free_key; | |
1da177e4 | 899 | } |
4b7137ff | 900 | |
38320c70 HX |
901 | param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); |
902 | memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); | |
903 | ||
904 | err = crypto_aead_setkey(aead, key, keylen); | |
905 | ||
906 | free_key: | |
907 | kfree(key); | |
908 | ||
1a6509d9 HX |
909 | error: |
910 | return err; | |
911 | } | |
912 | ||
913 | static int esp_init_state(struct xfrm_state *x) | |
914 | { | |
1a6509d9 HX |
915 | struct crypto_aead *aead; |
916 | u32 align; | |
917 | int err; | |
918 | ||
1c5ad13f | 919 | x->data = NULL; |
1a6509d9 HX |
920 | |
921 | if (x->aead) | |
922 | err = esp_init_aead(x); | |
923 | else | |
924 | err = esp_init_authenc(x); | |
925 | ||
38320c70 | 926 | if (err) |
1da177e4 | 927 | goto error; |
38320c70 | 928 | |
1c5ad13f | 929 | aead = x->data; |
1a6509d9 | 930 | |
38320c70 HX |
931 | x->props.header_len = sizeof(struct ip_esp_hdr) + |
932 | crypto_aead_ivsize(aead); | |
7e49e6de | 933 | if (x->props.mode == XFRM_MODE_TUNNEL) |
1da177e4 | 934 | x->props.header_len += sizeof(struct iphdr); |
eb49e630 | 935 | else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6) |
ac758e3c | 936 | x->props.header_len += IPV4_BEET_PHMAXLEN; |
1da177e4 LT |
937 | if (x->encap) { |
938 | struct xfrm_encap_tmpl *encap = x->encap; | |
939 | ||
940 | switch (encap->encap_type) { | |
941 | default: | |
942 | goto error; | |
943 | case UDP_ENCAP_ESPINUDP: | |
944 | x->props.header_len += sizeof(struct udphdr); | |
945 | break; | |
946 | case UDP_ENCAP_ESPINUDP_NON_IKE: | |
947 | x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32); | |
948 | break; | |
949 | } | |
950 | } | |
38320c70 HX |
951 | |
952 | align = ALIGN(crypto_aead_blocksize(aead), 4); | |
1c5ad13f | 953 | x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); |
1da177e4 LT |
954 | |
955 | error: | |
38320c70 | 956 | return err; |
1da177e4 LT |
957 | } |
958 | ||
827789cb SK |
959 | static int esp4_rcv_cb(struct sk_buff *skb, int err) |
960 | { | |
961 | return 0; | |
962 | } | |
963 | ||
533cb5b0 | 964 | static const struct xfrm_type esp_type = |
1da177e4 LT |
965 | { |
966 | .description = "ESP4", | |
967 | .owner = THIS_MODULE, | |
968 | .proto = IPPROTO_ESP, | |
436a0a40 | 969 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
970 | .init_state = esp_init_state, |
971 | .destructor = esp_destroy, | |
c5c25238 | 972 | .get_mtu = esp4_get_mtu, |
1da177e4 | 973 | .input = esp_input, |
fca11ebd | 974 | .output = esp_output, |
1da177e4 LT |
975 | }; |
976 | ||
827789cb | 977 | static struct xfrm4_protocol esp4_protocol = { |
1da177e4 | 978 | .handler = xfrm4_rcv, |
827789cb SK |
979 | .input_handler = xfrm_input, |
980 | .cb_handler = esp4_rcv_cb, | |
1da177e4 | 981 | .err_handler = esp4_err, |
827789cb | 982 | .priority = 0, |
1da177e4 LT |
983 | }; |
984 | ||
985 | static int __init esp4_init(void) | |
986 | { | |
1da177e4 | 987 | if (xfrm_register_type(&esp_type, AF_INET) < 0) { |
058bd4d2 | 988 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
989 | return -EAGAIN; |
990 | } | |
827789cb | 991 | if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) { |
058bd4d2 | 992 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
993 | xfrm_unregister_type(&esp_type, AF_INET); |
994 | return -EAGAIN; | |
995 | } | |
996 | return 0; | |
997 | } | |
998 | ||
999 | static void __exit esp4_fini(void) | |
1000 | { | |
827789cb | 1001 | if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0) |
058bd4d2 | 1002 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 | 1003 | if (xfrm_unregister_type(&esp_type, AF_INET) < 0) |
058bd4d2 | 1004 | pr_info("%s: can't remove xfrm type\n", __func__); |
1da177e4 LT |
1005 | } |
1006 | ||
1007 | module_init(esp4_init); | |
1008 | module_exit(esp4_fini); | |
1009 | MODULE_LICENSE("GPL"); | |
d3d6dd3a | 1010 | MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP); |