xref: /freebsd/sys/opencrypto/criov.c (revision f499134dd403eeeba8283e2640e2654c8da62430)
1 /*      $OpenBSD: criov.c,v 1.9 2002/01/29 15:48:29 jason Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 Theo de Raadt
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *   notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *   notice, this list of conditions and the following disclaimer in the
14  *   documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *   derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/proc.h>
36 #include <sys/errno.h>
37 #include <sys/malloc.h>
38 #include <sys/kernel.h>
39 #include <sys/mbuf.h>
40 #include <sys/uio.h>
41 #include <sys/limits.h>
42 #include <sys/lock.h>
43 #include <sys/sdt.h>
44 
45 #include <machine/vmparam.h>
46 
47 #include <vm/vm.h>
48 #include <vm/vm_page.h>
49 #include <vm/pmap.h>
50 
51 #include <opencrypto/cryptodev.h>
52 
53 SDT_PROVIDER_DECLARE(opencrypto);
54 
55 /*
56  * These macros are only for avoiding code duplication, as we need to skip
57  * given number of bytes in the same way in several functions below.
58  */
59 #define	CUIO_SKIP()	do {						\
60 	KASSERT(off >= 0, ("%s: off %d < 0", __func__, off));		\
61 	KASSERT(len >= 0, ("%s: len %d < 0", __func__, len));		\
62 	while (off > 0) {						\
63 		KASSERT(iol >= 0, ("%s: empty in skip", __func__));	\
64 		if (off < iov->iov_len)					\
65 			break;						\
66 		off -= iov->iov_len;					\
67 		iol--;							\
68 		iov++;							\
69 	}								\
70 } while (0)
71 
72 #define CVM_PAGE_SKIP()	do {					\
73 	KASSERT(off >= 0, ("%s: off %d < 0", __func__, off));		\
74 	KASSERT(len >= 0, ("%s: len %d < 0", __func__, len));		\
75 	while (off > 0) {						\
76 		if (off < PAGE_SIZE)					\
77 			break;						\
78 		processed += PAGE_SIZE - off;				\
79 		off -= PAGE_SIZE - off;					\
80 		pages++;						\
81 	}								\
82 } while (0)
83 
84 static void
85 cuio_copydata(struct uio* uio, int off, int len, caddr_t cp)
86 {
87 	struct iovec *iov = uio->uio_iov;
88 	int iol = uio->uio_iovcnt;
89 	unsigned count;
90 
91 	CUIO_SKIP();
92 	while (len > 0) {
93 		KASSERT(iol >= 0, ("%s: empty", __func__));
94 		count = min(iov->iov_len - off, len);
95 		bcopy(((caddr_t)iov->iov_base) + off, cp, count);
96 		len -= count;
97 		cp += count;
98 		off = 0;
99 		iol--;
100 		iov++;
101 	}
102 }
103 
104 static void
105 cuio_copyback(struct uio* uio, int off, int len, c_caddr_t cp)
106 {
107 	struct iovec *iov = uio->uio_iov;
108 	int iol = uio->uio_iovcnt;
109 	unsigned count;
110 
111 	CUIO_SKIP();
112 	while (len > 0) {
113 		KASSERT(iol >= 0, ("%s: empty", __func__));
114 		count = min(iov->iov_len - off, len);
115 		bcopy(cp, ((caddr_t)iov->iov_base) + off, count);
116 		len -= count;
117 		cp += count;
118 		off = 0;
119 		iol--;
120 		iov++;
121 	}
122 }
123 
124 /*
125  * Return the index and offset of location in iovec list.
126  */
127 static int
128 cuio_getptr(struct uio *uio, int loc, int *off)
129 {
130 	int ind, len;
131 
132 	ind = 0;
133 	while (loc >= 0 && ind < uio->uio_iovcnt) {
134 		len = uio->uio_iov[ind].iov_len;
135 		if (len > loc) {
136 	    		*off = loc;
137 	    		return (ind);
138 		}
139 		loc -= len;
140 		ind++;
141 	}
142 
143 	if (ind > 0 && loc == 0) {
144 		ind--;
145 		*off = uio->uio_iov[ind].iov_len;
146 		return (ind);
147 	}
148 
149 	return (-1);
150 }
151 
152 #if CRYPTO_MAY_HAVE_VMPAGE
153 /*
154  * Apply function f to the data in a vm_page_t list starting "off" bytes from
155  * the beginning, continuing for "len" bytes.
156  */
157 static int
158 cvm_page_apply(vm_page_t *pages, int off, int len,
159     int (*f)(void *, const void *, u_int), void *arg)
160 {
161 	int processed __unused;
162 	unsigned count;
163 	int rval;
164 
165 	processed = 0;
166 	CVM_PAGE_SKIP();
167 	while (len > 0) {
168 		char *kaddr = (char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(*pages));
169 		count = min(PAGE_SIZE - off, len);
170 		rval = (*f)(arg, kaddr + off, count);
171 		if (rval)
172 			return (rval);
173 		len -= count;
174 		processed += count;
175 		off = 0;
176 		pages++;
177 	}
178 	return (0);
179 }
180 
181 static inline void *
182 cvm_page_contiguous_segment(vm_page_t *pages, size_t skip, int len)
183 {
184 	if ((skip + len - 1) / PAGE_SIZE > skip / PAGE_SIZE)
185 		return (NULL);
186 
187 	pages += (skip / PAGE_SIZE);
188 	skip -= rounddown(skip, PAGE_SIZE);
189 	return (((char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(*pages))) + skip);
190 }
191 
192 /*
193  * Copy len bytes of data from the vm_page_t array, skipping the first off
194  * bytes, into the pointer cp.  Return the number of bytes skipped and copied.
195  * Does not verify the length of the array.
196  */
197 static int
198 cvm_page_copyback(vm_page_t *pages, int off, int len, c_caddr_t cp)
199 {
200 	int processed = 0;
201 	unsigned count;
202 
203 	CVM_PAGE_SKIP();
204 	while (len > 0) {
205 		count = min(PAGE_SIZE - off, len);
206 		bcopy(cp, (char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(*pages)) + off,
207 		    count);
208 		len -= count;
209 		cp += count;
210 		processed += count;
211 		off = 0;
212 		pages++;
213 	}
214 	return (processed);
215 }
216 
217 /*
218  * Copy len bytes of data from the pointer cp into the vm_page_t array,
219  * skipping the first off bytes, Return the number of bytes skipped and copied.
220  * Does not verify the length of the array.
221  */
222 static int
223 cvm_page_copydata(vm_page_t *pages, int off, int len, caddr_t cp)
224 {
225 	int processed = 0;
226 	unsigned count;
227 
228 	CVM_PAGE_SKIP();
229 	while (len > 0) {
230 		count = min(PAGE_SIZE - off, len);
231 		bcopy(((char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(*pages)) + off), cp,
232 		    count);
233 		len -= count;
234 		cp += count;
235 		processed += count;
236 		off = 0;
237 		pages++;
238 	}
239 	return processed;
240 }
241 #endif /* CRYPTO_MAY_HAVE_VMPAGE */
242 
243 /*
244  * Given a starting page in an m_epg, determine the length of the
245  * current physically contiguous segment.
246  */
247 static __inline size_t
248 m_epg_pages_extent(struct mbuf *m, int idx, u_int pglen)
249 {
250 	size_t len;
251 	u_int i;
252 
253 	len = pglen;
254 	for (i = idx + 1; i < m->m_epg_npgs; i++) {
255 		if (m->m_epg_pa[i - 1] + PAGE_SIZE != m->m_epg_pa[i])
256 			break;
257 		len += m_epg_pagelen(m, i, 0);
258 	}
259 	return (len);
260 }
261 
262 static void *
263 m_epg_segment(struct mbuf *m, size_t offset, size_t *len)
264 {
265 	u_int i, pglen, pgoff;
266 
267 	offset += mtod(m, vm_offset_t);
268 	if (offset < m->m_epg_hdrlen) {
269 		*len = m->m_epg_hdrlen - offset;
270 		return (m->m_epg_hdr + offset);
271 	}
272 	offset -= m->m_epg_hdrlen;
273 	pgoff = m->m_epg_1st_off;
274 	for (i = 0; i < m->m_epg_npgs; i++) {
275 		pglen = m_epg_pagelen(m, i, pgoff);
276 		if (offset < pglen) {
277 			*len = m_epg_pages_extent(m, i, pglen) - offset;
278 			return ((void *)PHYS_TO_DMAP(m->m_epg_pa[i] + pgoff +
279 			    offset));
280 		}
281 		offset -= pglen;
282 		pgoff = 0;
283 	}
284 	KASSERT(offset <= m->m_epg_trllen, ("%s: offset beyond trailer",
285 	    __func__));
286 	*len = m->m_epg_trllen - offset;
287 	return (m->m_epg_trail + offset);
288 }
289 
290 static __inline void *
291 m_epg_contiguous_subsegment(struct mbuf *m, size_t skip, size_t len)
292 {
293 	void *base;
294 	size_t seglen;
295 
296 	base = m_epg_segment(m, skip, &seglen);
297 	if (len > seglen)
298 		return (NULL);
299 	return (base);
300 }
301 
302 void
303 crypto_cursor_init(struct crypto_buffer_cursor *cc,
304     const struct crypto_buffer *cb)
305 {
306 	memset(cc, 0, sizeof(*cc));
307 	cc->cc_type = cb->cb_type;
308 	switch (cc->cc_type) {
309 	case CRYPTO_BUF_CONTIG:
310 		cc->cc_buf = cb->cb_buf;
311 		cc->cc_buf_len = cb->cb_buf_len;
312 		break;
313 	case CRYPTO_BUF_MBUF:
314 	case CRYPTO_BUF_SINGLE_MBUF:
315 		cc->cc_mbuf = cb->cb_mbuf;
316 		break;
317 	case CRYPTO_BUF_VMPAGE:
318 		cc->cc_vmpage = cb->cb_vm_page;
319 		cc->cc_buf_len = cb->cb_vm_page_len;
320 		cc->cc_offset = cb->cb_vm_page_offset;
321 		break;
322 	case CRYPTO_BUF_UIO:
323 		cc->cc_iov = cb->cb_uio->uio_iov;
324 		break;
325 	default:
326 #ifdef INVARIANTS
327 		panic("%s: invalid buffer type %d", __func__, cb->cb_type);
328 #endif
329 		break;
330 	}
331 }
332 
333 SDT_PROBE_DEFINE2(opencrypto, criov, cursor_advance, vmpage, "struct crypto_buffer_cursor*", "size_t");
334 
335 void
336 crypto_cursor_advance(struct crypto_buffer_cursor *cc, size_t amount)
337 {
338 	size_t remain;
339 
340 	switch (cc->cc_type) {
341 	case CRYPTO_BUF_CONTIG:
342 		MPASS(cc->cc_buf_len >= amount);
343 		cc->cc_buf += amount;
344 		cc->cc_buf_len -= amount;
345 		break;
346 	case CRYPTO_BUF_MBUF:
347 		for (;;) {
348 			remain = cc->cc_mbuf->m_len - cc->cc_offset;
349 			if (amount < remain) {
350 				cc->cc_offset += amount;
351 				break;
352 			}
353 			amount -= remain;
354 			cc->cc_mbuf = cc->cc_mbuf->m_next;
355 			cc->cc_offset = 0;
356 			if (amount == 0)
357 				break;
358 		}
359 		break;
360 	case CRYPTO_BUF_SINGLE_MBUF:
361 		MPASS(cc->cc_mbuf->m_len >= cc->cc_offset + amount);
362 		cc->cc_offset += amount;
363 		break;
364 	case CRYPTO_BUF_VMPAGE:
365 		for (;;) {
366 			SDT_PROBE2(opencrypto, criov, cursor_advance, vmpage,
367 			    cc, amount);
368 			remain = MIN(PAGE_SIZE - cc->cc_offset, cc->cc_buf_len);
369 			if (amount < remain) {
370 				cc->cc_buf_len -= amount;
371 				cc->cc_offset += amount;
372 				break;
373 			}
374 			cc->cc_buf_len -= remain;
375 			amount -= remain;
376 			cc->cc_vmpage++;
377 			cc->cc_offset = 0;
378 			if (amount == 0 || cc->cc_buf_len == 0)
379 				break;
380 		}
381 		break;
382 	case CRYPTO_BUF_UIO:
383 		for (;;) {
384 			remain = cc->cc_iov->iov_len - cc->cc_offset;
385 			if (amount < remain) {
386 				cc->cc_offset += amount;
387 				break;
388 			}
389 			amount -= remain;
390 			cc->cc_iov++;
391 			cc->cc_offset = 0;
392 			if (amount == 0)
393 				break;
394 		}
395 		break;
396 	default:
397 #ifdef INVARIANTS
398 		panic("%s: invalid buffer type %d", __func__, cc->cc_type);
399 #endif
400 		break;
401 	}
402 }
403 
404 void *
405 crypto_cursor_segment(struct crypto_buffer_cursor *cc, size_t *len)
406 {
407 	switch (cc->cc_type) {
408 	case CRYPTO_BUF_CONTIG:
409 		*len = cc->cc_buf_len;
410 		return (cc->cc_buf);
411 	case CRYPTO_BUF_MBUF:
412 	case CRYPTO_BUF_SINGLE_MBUF:
413 		if (cc->cc_mbuf == NULL) {
414 			*len = 0;
415 			return (NULL);
416 		}
417 		if (cc->cc_mbuf->m_flags & M_EXTPG)
418 			return (m_epg_segment(cc->cc_mbuf, cc->cc_offset, len));
419 		*len = cc->cc_mbuf->m_len - cc->cc_offset;
420 		return (mtod(cc->cc_mbuf, char *) + cc->cc_offset);
421 	case CRYPTO_BUF_VMPAGE:
422 		*len = PAGE_SIZE - cc->cc_offset;
423 		return ((char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(
424 		    *cc->cc_vmpage)) + cc->cc_offset);
425 	case CRYPTO_BUF_UIO:
426 		*len = cc->cc_iov->iov_len - cc->cc_offset;
427 		return ((char *)cc->cc_iov->iov_base + cc->cc_offset);
428 	default:
429 #ifdef INVARIANTS
430 		panic("%s: invalid buffer type %d", __func__, cc->cc_type);
431 #endif
432 		*len = 0;
433 		return (NULL);
434 	}
435 }
436 
437 void
438 crypto_cursor_copyback(struct crypto_buffer_cursor *cc, int size,
439     const void *vsrc)
440 {
441 	size_t remain, todo;
442 	const char *src;
443 	char *dst;
444 
445 	src = vsrc;
446 	switch (cc->cc_type) {
447 	case CRYPTO_BUF_CONTIG:
448 		MPASS(cc->cc_buf_len >= size);
449 		memcpy(cc->cc_buf, src, size);
450 		cc->cc_buf += size;
451 		cc->cc_buf_len -= size;
452 		break;
453 	case CRYPTO_BUF_MBUF:
454 		for (;;) {
455 			/*
456 			 * This uses m_copyback() for individual
457 			 * mbufs so that cc_mbuf and cc_offset are
458 			 * updated.
459 			 */
460 			remain = cc->cc_mbuf->m_len - cc->cc_offset;
461 			todo = MIN(remain, size);
462 			m_copyback(cc->cc_mbuf, cc->cc_offset, todo, src);
463 			src += todo;
464 			if (todo < remain) {
465 				cc->cc_offset += todo;
466 				break;
467 			}
468 			size -= todo;
469 			cc->cc_mbuf = cc->cc_mbuf->m_next;
470 			cc->cc_offset = 0;
471 			if (size == 0)
472 				break;
473 		}
474 		break;
475 	case CRYPTO_BUF_SINGLE_MBUF:
476 		MPASS(cc->cc_mbuf->m_len >= cc->cc_offset + size);
477 		m_copyback(cc->cc_mbuf, cc->cc_offset, size, src);
478 		cc->cc_offset += size;
479 		break;
480 	case CRYPTO_BUF_VMPAGE:
481 		for (;;) {
482 			dst = (char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(
483 			    *cc->cc_vmpage)) + cc->cc_offset;
484 			remain = MIN(PAGE_SIZE - cc->cc_offset, cc->cc_buf_len);
485 			todo = MIN(remain, size);
486 			memcpy(dst, src, todo);
487 			src += todo;
488 			cc->cc_buf_len -= todo;
489 			if (todo < remain) {
490 				cc->cc_offset += todo;
491 				break;
492 			}
493 			size -= todo;
494 			cc->cc_vmpage++;
495 			cc->cc_offset = 0;
496 			if (size == 0)
497 				break;
498 		}
499 		break;
500 	case CRYPTO_BUF_UIO:
501 		for (;;) {
502 			dst = (char *)cc->cc_iov->iov_base + cc->cc_offset;
503 			remain = cc->cc_iov->iov_len - cc->cc_offset;
504 			todo = MIN(remain, size);
505 			memcpy(dst, src, todo);
506 			src += todo;
507 			if (todo < remain) {
508 				cc->cc_offset += todo;
509 				break;
510 			}
511 			size -= todo;
512 			cc->cc_iov++;
513 			cc->cc_offset = 0;
514 			if (size == 0)
515 				break;
516 		}
517 		break;
518 	default:
519 #ifdef INVARIANTS
520 		panic("%s: invalid buffer type %d", __func__, cc->cc_type);
521 #endif
522 		break;
523 	}
524 }
525 
526 void
527 crypto_cursor_copydata(struct crypto_buffer_cursor *cc, int size, void *vdst)
528 {
529 	size_t remain, todo;
530 	const char *src;
531 	char *dst;
532 
533 	dst = vdst;
534 	switch (cc->cc_type) {
535 	case CRYPTO_BUF_CONTIG:
536 		MPASS(cc->cc_buf_len >= size);
537 		memcpy(dst, cc->cc_buf, size);
538 		cc->cc_buf += size;
539 		cc->cc_buf_len -= size;
540 		break;
541 	case CRYPTO_BUF_MBUF:
542 		for (;;) {
543 			/*
544 			 * This uses m_copydata() for individual
545 			 * mbufs so that cc_mbuf and cc_offset are
546 			 * updated.
547 			 */
548 			remain = cc->cc_mbuf->m_len - cc->cc_offset;
549 			todo = MIN(remain, size);
550 			m_copydata(cc->cc_mbuf, cc->cc_offset, todo, dst);
551 			dst += todo;
552 			if (todo < remain) {
553 				cc->cc_offset += todo;
554 				break;
555 			}
556 			size -= todo;
557 			cc->cc_mbuf = cc->cc_mbuf->m_next;
558 			cc->cc_offset = 0;
559 			if (size == 0)
560 				break;
561 		}
562 		break;
563 	case CRYPTO_BUF_SINGLE_MBUF:
564 		MPASS(cc->cc_mbuf->m_len >= cc->cc_offset + size);
565 		m_copydata(cc->cc_mbuf, cc->cc_offset, size, dst);
566 		cc->cc_offset += size;
567 		break;
568 	case CRYPTO_BUF_VMPAGE:
569 		for (;;) {
570 			src = (char *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(
571 			    *cc->cc_vmpage)) + cc->cc_offset;
572 			remain = MIN(PAGE_SIZE - cc->cc_offset, cc->cc_buf_len);
573 			todo = MIN(remain, size);
574 			memcpy(dst, src, todo);
575 			src += todo;
576 			cc->cc_buf_len -= todo;
577 			if (todo < remain) {
578 				cc->cc_offset += todo;
579 				break;
580 			}
581 			size -= todo;
582 			cc->cc_vmpage++;
583 			cc->cc_offset = 0;
584 			if (size == 0)
585 				break;
586 		}
587 		break;
588 	case CRYPTO_BUF_UIO:
589 		for (;;) {
590 			src = (const char *)cc->cc_iov->iov_base +
591 			    cc->cc_offset;
592 			remain = cc->cc_iov->iov_len - cc->cc_offset;
593 			todo = MIN(remain, size);
594 			memcpy(dst, src, todo);
595 			dst += todo;
596 			if (todo < remain) {
597 				cc->cc_offset += todo;
598 				break;
599 			}
600 			size -= todo;
601 			cc->cc_iov++;
602 			cc->cc_offset = 0;
603 			if (size == 0)
604 				break;
605 		}
606 		break;
607 	default:
608 #ifdef INVARIANTS
609 		panic("%s: invalid buffer type %d", __func__, cc->cc_type);
610 #endif
611 		break;
612 	}
613 }
614 
615 /*
616  * To avoid advancing 'cursor', make a local copy that gets advanced
617  * instead.
618  */
619 void
620 crypto_cursor_copydata_noadv(struct crypto_buffer_cursor *cc, int size,
621     void *vdst)
622 {
623 	struct crypto_buffer_cursor copy;
624 
625 	copy = *cc;
626 	crypto_cursor_copydata(&copy, size, vdst);
627 }
628 
629 /*
630  * Apply function f to the data in an iovec list starting "off" bytes from
631  * the beginning, continuing for "len" bytes.
632  */
633 static int
634 cuio_apply(struct uio *uio, int off, int len,
635     int (*f)(void *, const void *, u_int), void *arg)
636 {
637 	struct iovec *iov = uio->uio_iov;
638 	int iol = uio->uio_iovcnt;
639 	unsigned count;
640 	int rval;
641 
642 	CUIO_SKIP();
643 	while (len > 0) {
644 		KASSERT(iol >= 0, ("%s: empty", __func__));
645 		count = min(iov->iov_len - off, len);
646 		rval = (*f)(arg, ((caddr_t)iov->iov_base) + off, count);
647 		if (rval)
648 			return (rval);
649 		len -= count;
650 		off = 0;
651 		iol--;
652 		iov++;
653 	}
654 	return (0);
655 }
656 
657 void
658 crypto_copyback(struct cryptop *crp, int off, int size, const void *src)
659 {
660 	struct crypto_buffer *cb;
661 
662 	if (crp->crp_obuf.cb_type != CRYPTO_BUF_NONE)
663 		cb = &crp->crp_obuf;
664 	else
665 		cb = &crp->crp_buf;
666 	switch (cb->cb_type) {
667 	case CRYPTO_BUF_MBUF:
668 	case CRYPTO_BUF_SINGLE_MBUF:
669 		m_copyback(cb->cb_mbuf, off, size, src);
670 		break;
671 #if CRYPTO_MAY_HAVE_VMPAGE
672 	case CRYPTO_BUF_VMPAGE:
673 		MPASS(size <= cb->cb_vm_page_len);
674 		MPASS(size + off <=
675 		    cb->cb_vm_page_len + cb->cb_vm_page_offset);
676 		cvm_page_copyback(cb->cb_vm_page,
677 		    off + cb->cb_vm_page_offset, size, src);
678 		break;
679 #endif /* CRYPTO_MAY_HAVE_VMPAGE */
680 	case CRYPTO_BUF_UIO:
681 		cuio_copyback(cb->cb_uio, off, size, src);
682 		break;
683 	case CRYPTO_BUF_CONTIG:
684 		MPASS(off + size <= cb->cb_buf_len);
685 		bcopy(src, cb->cb_buf + off, size);
686 		break;
687 	default:
688 #ifdef INVARIANTS
689 		panic("invalid crp buf type %d", cb->cb_type);
690 #endif
691 		break;
692 	}
693 }
694 
695 void
696 crypto_copydata(struct cryptop *crp, int off, int size, void *dst)
697 {
698 
699 	switch (crp->crp_buf.cb_type) {
700 	case CRYPTO_BUF_MBUF:
701 	case CRYPTO_BUF_SINGLE_MBUF:
702 		m_copydata(crp->crp_buf.cb_mbuf, off, size, dst);
703 		break;
704 #if CRYPTO_MAY_HAVE_VMPAGE
705 	case CRYPTO_BUF_VMPAGE:
706 		MPASS(size <= crp->crp_buf.cb_vm_page_len);
707 		MPASS(size + off <= crp->crp_buf.cb_vm_page_len +
708 		    crp->crp_buf.cb_vm_page_offset);
709 		cvm_page_copydata(crp->crp_buf.cb_vm_page,
710 		    off + crp->crp_buf.cb_vm_page_offset, size, dst);
711 		break;
712 #endif /* CRYPTO_MAY_HAVE_VMPAGE */
713 	case CRYPTO_BUF_UIO:
714 		cuio_copydata(crp->crp_buf.cb_uio, off, size, dst);
715 		break;
716 	case CRYPTO_BUF_CONTIG:
717 		MPASS(off + size <= crp->crp_buf.cb_buf_len);
718 		bcopy(crp->crp_buf.cb_buf + off, dst, size);
719 		break;
720 	default:
721 #ifdef INVARIANTS
722 		panic("invalid crp buf type %d", crp->crp_buf.cb_type);
723 #endif
724 		break;
725 	}
726 }
727 
728 int
729 crypto_apply_buf(struct crypto_buffer *cb, int off, int len,
730     int (*f)(void *, const void *, u_int), void *arg)
731 {
732 	int error;
733 
734 	switch (cb->cb_type) {
735 	case CRYPTO_BUF_MBUF:
736 	case CRYPTO_BUF_SINGLE_MBUF:
737 		error = m_apply(cb->cb_mbuf, off, len,
738 		    (int (*)(void *, void *, u_int))f, arg);
739 		break;
740 	case CRYPTO_BUF_UIO:
741 		error = cuio_apply(cb->cb_uio, off, len, f, arg);
742 		break;
743 #if CRYPTO_MAY_HAVE_VMPAGE
744 	case CRYPTO_BUF_VMPAGE:
745 		error = cvm_page_apply(cb->cb_vm_page,
746 		    off + cb->cb_vm_page_offset, len, f, arg);
747 		break;
748 #endif /* CRYPTO_MAY_HAVE_VMPAGE */
749 	case CRYPTO_BUF_CONTIG:
750 		MPASS(off + len <= cb->cb_buf_len);
751 		error = (*f)(arg, cb->cb_buf + off, len);
752 		break;
753 	default:
754 #ifdef INVARIANTS
755 		panic("invalid crypto buf type %d", cb->cb_type);
756 #endif
757 		error = 0;
758 		break;
759 	}
760 	return (error);
761 }
762 
763 int
764 crypto_apply(struct cryptop *crp, int off, int len,
765     int (*f)(void *, const void *, u_int), void *arg)
766 {
767 	return (crypto_apply_buf(&crp->crp_buf, off, len, f, arg));
768 }
769 
770 static inline void *
771 m_contiguous_subsegment(struct mbuf *m, size_t skip, size_t len)
772 {
773 	int rel_off;
774 
775 	MPASS(skip <= INT_MAX);
776 
777 	m = m_getptr(m, (int)skip, &rel_off);
778 	if (m == NULL)
779 		return (NULL);
780 
781 	MPASS(rel_off >= 0);
782 	skip = rel_off;
783 	if (skip + len > m->m_len)
784 		return (NULL);
785 
786 	if (m->m_flags & M_EXTPG)
787 		return (m_epg_contiguous_subsegment(m, skip, len));
788 	return (mtod(m, char*) + skip);
789 }
790 
791 static inline void *
792 cuio_contiguous_segment(struct uio *uio, size_t skip, size_t len)
793 {
794 	int rel_off, idx;
795 
796 	MPASS(skip <= INT_MAX);
797 	idx = cuio_getptr(uio, (int)skip, &rel_off);
798 	if (idx < 0)
799 		return (NULL);
800 
801 	MPASS(rel_off >= 0);
802 	skip = rel_off;
803 	if (skip + len > uio->uio_iov[idx].iov_len)
804 		return (NULL);
805 	return ((char *)uio->uio_iov[idx].iov_base + skip);
806 }
807 
808 void *
809 crypto_buffer_contiguous_subsegment(struct crypto_buffer *cb, size_t skip,
810     size_t len)
811 {
812 
813 	switch (cb->cb_type) {
814 	case CRYPTO_BUF_MBUF:
815 	case CRYPTO_BUF_SINGLE_MBUF:
816 		return (m_contiguous_subsegment(cb->cb_mbuf, skip, len));
817 	case CRYPTO_BUF_UIO:
818 		return (cuio_contiguous_segment(cb->cb_uio, skip, len));
819 #if CRYPTO_MAY_HAVE_VMPAGE
820 	case CRYPTO_BUF_VMPAGE:
821 		MPASS(skip + len <= cb->cb_vm_page_len);
822 		return (cvm_page_contiguous_segment(cb->cb_vm_page,
823 		    skip + cb->cb_vm_page_offset, len));
824 #endif /* CRYPTO_MAY_HAVE_VMPAGE */
825 	case CRYPTO_BUF_CONTIG:
826 		MPASS(skip + len <= cb->cb_buf_len);
827 		return (cb->cb_buf + skip);
828 	default:
829 #ifdef INVARIANTS
830 		panic("invalid crp buf type %d", cb->cb_type);
831 #endif
832 		return (NULL);
833 	}
834 }
835 
836 void *
837 crypto_contiguous_subsegment(struct cryptop *crp, size_t skip, size_t len)
838 {
839 	return (crypto_buffer_contiguous_subsegment(&crp->crp_buf, skip, len));
840 }
841