1 /*	$NetBSD: subr_mchain.c,v 1.23 2014/11/15 18:52:45 nakayama Exp $	*/
2 
3 /*
4  * Copyright (c) 2000, 2001 Boris Popov
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *    This product includes software developed by Boris Popov.
18  * 4. Neither the name of the author nor the names of any co-contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * FreeBSD: src/sys/kern/subr_mchain.c,v 1.4 2002/02/21 16:23:38 bp Exp
35  */
36 
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: subr_mchain.c,v 1.23 2014/11/15 18:52:45 nakayama Exp $");
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/errno.h>
43 #include <sys/mbuf.h>
44 #include <sys/uio.h>
45 
46 #include <uvm/uvm_extern.h>
47 
48 #include <netsmb/mchain.h>
49 
50 #define MBERROR(x)	aprint_error x
51 #define MBPANIC(x)	aprint_error x
52 
53 static struct mbuf *
m_getm(struct mbuf * m,size_t len,int how,int type)54 m_getm(struct mbuf *m, size_t len, int how, int type)
55 {
56 	struct mbuf *top, *tail, *mp, *mtail = NULL;
57 
58 	mp = m_get(how, type);
59 	if (mp == NULL)
60 		return (NULL);
61 	else if (len > MINCLSIZE) {
62 		m_clget(mp, how);
63 		if ((mp->m_flags & M_EXT) == 0) {
64 			m_free(mp);
65 			return (NULL);
66 		}
67 	}
68 	mp->m_len = 0;
69 	len -= min(len, M_TRAILINGSPACE(mp));
70 
71 	if (m != NULL)
72 		for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next);
73 	else
74 		m = mp;
75 
76 	top = tail = mp;
77 	while (len > 0) {
78 		mp = m_get(how, type);
79 		if (mp == NULL)
80 			goto failed;
81 
82 		tail->m_next = mp;
83 		tail = mp;
84 		if (len > MINCLSIZE) {
85 			m_clget(mp, how);
86 			if ((mp->m_flags & M_EXT) == 0)
87 				goto failed;
88 		}
89 
90 		mp->m_len = 0;
91 		len -= min(len, M_TRAILINGSPACE(mp));
92 	}
93 
94 	if (mtail != NULL)
95 		mtail->m_next = top;
96 	return (m);
97 
98 failed:
99 	m_freem(top);
100 	return (NULL);
101 }
102 
103 
104 /*
105  * Various helper functions
106  */
107 int
m_fixhdr(struct mbuf * m0)108 m_fixhdr(struct mbuf *m0)
109 {
110 	struct mbuf *m = m0;
111 	size_t len = 0;
112 
113 	while (m) {
114 		len += m->m_len;
115 		m = m->m_next;
116 	}
117 	m0->m_pkthdr.len = len;
118 	return len;
119 }
120 
121 int
mb_init(struct mbchain * mbp)122 mb_init(struct mbchain *mbp)
123 {
124 	struct mbuf *m;
125 
126 	m = m_gethdr(M_WAIT, MT_DATA);
127 	if (m == NULL)
128 		return ENOBUFS;
129 	m->m_len = 0;
130 	mb_initm(mbp, m);
131 	return 0;
132 }
133 
134 void
mb_initm(struct mbchain * mbp,struct mbuf * m)135 mb_initm(struct mbchain *mbp, struct mbuf *m)
136 {
137 	memset(mbp, 0, sizeof(*mbp));
138 	mbp->mb_top = mbp->mb_cur = m;
139 	mbp->mb_mleft = M_TRAILINGSPACE(m);
140 }
141 
142 void
mb_done(struct mbchain * mbp)143 mb_done(struct mbchain *mbp)
144 {
145 	if (mbp->mb_top) {
146 		m_freem(mbp->mb_top);
147 		mbp->mb_top = NULL;
148 	}
149 }
150 
151 struct mbuf *
mb_detach(struct mbchain * mbp)152 mb_detach(struct mbchain *mbp)
153 {
154 	struct mbuf *m;
155 
156 	m = mbp->mb_top;
157 	mbp->mb_top = NULL;
158 	return m;
159 }
160 
161 int
mb_fixhdr(struct mbchain * mbp)162 mb_fixhdr(struct mbchain *mbp)
163 {
164 	return mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top);
165 }
166 
167 /*
168  * Check if object of size 'size' fit to the current position and
169  * allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
170  * Return pointer to the object placeholder or NULL if any error occurred.
171  * Note: size should be <= MLEN
172  */
173 void *
mb_reserve(struct mbchain * mbp,size_t size)174 mb_reserve(struct mbchain *mbp, size_t size)
175 {
176 	struct mbuf *m, *mn;
177 	void *bpos;
178 
179 	if (size > MLEN)
180 		panic("mb_reserve: size = %zu", size);
181 	m = mbp->mb_cur;
182 	if (mbp->mb_mleft < size) {
183 		mn = m_get(M_WAIT, MT_DATA);
184 		if (mn == NULL)
185 			return NULL;
186 		mbp->mb_cur = m->m_next = mn;
187 		m = mn;
188 		m->m_len = 0;
189 		mbp->mb_mleft = M_TRAILINGSPACE(m);
190 	}
191 	mbp->mb_mleft -= size;
192 	mbp->mb_count += size;
193 	bpos = mtod(m, char *) + m->m_len;
194 	m->m_len += size;
195 	return bpos;
196 }
197 
198 int
mb_put_uint8(struct mbchain * mbp,u_int8_t x)199 mb_put_uint8(struct mbchain *mbp, u_int8_t x)
200 {
201 	return mb_put_mem(mbp, (void *)&x, sizeof(x), MB_MSYSTEM);
202 }
203 
204 int
mb_put_uint16be(struct mbchain * mbp,u_int16_t x)205 mb_put_uint16be(struct mbchain *mbp, u_int16_t x)
206 {
207 	x = htobe16(x);
208 	return mb_put_mem(mbp, (void *)&x, sizeof(x), MB_MSYSTEM);
209 }
210 
211 int
mb_put_uint16le(struct mbchain * mbp,u_int16_t x)212 mb_put_uint16le(struct mbchain *mbp, u_int16_t x)
213 {
214 	x = htole16(x);
215 	return mb_put_mem(mbp, (void *)&x, sizeof(x), MB_MSYSTEM);
216 }
217 
218 int
mb_put_uint32be(struct mbchain * mbp,u_int32_t x)219 mb_put_uint32be(struct mbchain *mbp, u_int32_t x)
220 {
221 	x = htobe32(x);
222 	return mb_put_mem(mbp, (void *)&x, sizeof(x), MB_MSYSTEM);
223 }
224 
225 int
mb_put_uint32le(struct mbchain * mbp,u_int32_t x)226 mb_put_uint32le(struct mbchain *mbp, u_int32_t x)
227 {
228 	x = htole32(x);
229 	return mb_put_mem(mbp, (void *)&x, sizeof(x), MB_MSYSTEM);
230 }
231 
232 int
mb_put_int64be(struct mbchain * mbp,int64_t x)233 mb_put_int64be(struct mbchain *mbp, int64_t x)
234 {
235 	x = htobe64(x);
236 	return mb_put_mem(mbp, (void *)&x, sizeof(x), MB_MSYSTEM);
237 }
238 
239 int
mb_put_int64le(struct mbchain * mbp,int64_t x)240 mb_put_int64le(struct mbchain *mbp, int64_t x)
241 {
242 	x = htole64(x);
243 	return mb_put_mem(mbp, (void *)&x, sizeof(x), MB_MSYSTEM);
244 }
245 
246 int
mb_put_mem(struct mbchain * mbp,const char * source,size_t size,int type)247 mb_put_mem(struct mbchain *mbp, const char *source, size_t size, int type)
248 {
249 	struct mbuf *m;
250 	char *dst;
251 	const char *src;
252 	int error;
253 	size_t cplen, mleft, count;
254 	size_t srclen, dstlen;
255 
256 	m = mbp->mb_cur;
257 	mleft = mbp->mb_mleft;
258 
259 	while (size > 0) {
260 		if (mleft == 0) {
261 			if (m->m_next == NULL) {
262 				m = m_getm(m, size, M_WAIT, MT_DATA);
263 				if (m == NULL)
264 					return ENOBUFS;
265 			}
266 			m = m->m_next;
267 			mleft = M_TRAILINGSPACE(m);
268 			continue;
269 		}
270 		cplen = mleft > size ? size : mleft;
271 		srclen = dstlen = cplen;
272 		dst = mtod(m, char *) + m->m_len;
273 		switch (type) {
274 		    case MB_MCUSTOM:
275 			srclen = size;
276 			dstlen = mleft;
277 			error = mbp->mb_copy(mbp, source, dst, &srclen, &dstlen);
278 			if (error == E2BIG) {
279 				mleft = 0;
280 				continue;
281 			}
282 			if (error)
283 				return error;
284 			break;
285 		    case MB_MINLINE:
286 			for (src = source, count = cplen; count; count--)
287 				*dst++ = *src++;
288 			break;
289 		    case MB_MSYSTEM:
290 			memcpy(dst, source, cplen);
291 			break;
292 		    case MB_MUSER:
293 			error = copyin(source, dst, cplen);
294 			if (error)
295 				return error;
296 			break;
297 		    case MB_MZERO:
298 			memset(dst, 0, cplen);
299 			break;
300 		}
301 		size -= srclen;
302 		source += srclen;
303 		m->m_len += dstlen;
304 		mleft -= dstlen;
305 		mbp->mb_count += dstlen;
306 	}
307 	mbp->mb_cur = m;
308 	mbp->mb_mleft = mleft;
309 	return 0;
310 }
311 
312 int
mb_put_mbuf(struct mbchain * mbp,struct mbuf * m)313 mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
314 {
315 	mbp->mb_cur->m_next = m;
316 	while (m) {
317 		mbp->mb_count += m->m_len;
318 		if (m->m_next == NULL)
319 			break;
320 		m = m->m_next;
321 	}
322 	mbp->mb_mleft = M_TRAILINGSPACE(m);
323 	mbp->mb_cur = m;
324 	return 0;
325 }
326 
327 /*
328  * copies a uio scatter/gather list to an mbuf chain.
329  */
330 int
mb_put_uio(struct mbchain * mbp,struct uio * uiop,size_t size)331 mb_put_uio(struct mbchain *mbp, struct uio *uiop, size_t size)
332 {
333 	size_t left;
334 	int mtype, error;
335 
336 	mtype = VMSPACE_IS_KERNEL_P(uiop->uio_vmspace) ? MB_MSYSTEM : MB_MUSER;
337 
338 	while (size > 0 && uiop->uio_resid) {
339 		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
340 			return EFBIG;
341 		left = uiop->uio_iov->iov_len;
342 		if (left == 0) {
343 			uiop->uio_iov++;
344 			uiop->uio_iovcnt--;
345 			continue;
346 		}
347 		if (left > size)
348 			left = size;
349 		error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
350 		if (error)
351 			return error;
352 		uiop->uio_offset += left;
353 		uiop->uio_resid -= left;
354 		uiop->uio_iov->iov_base =
355 			(char *)uiop->uio_iov->iov_base + left;
356 		uiop->uio_iov->iov_len -= left;
357 		size -= left;
358 	}
359 	return 0;
360 }
361 
362 /*
363  * Routines for fetching data from an mbuf chain
364  */
365 int
md_init(struct mdchain * mdp)366 md_init(struct mdchain *mdp)
367 {
368 	struct mbuf *m;
369 
370 	m = m_gethdr(M_WAIT, MT_DATA);
371 	if (m == NULL)
372 		return ENOBUFS;
373 	m->m_len = 0;
374 	md_initm(mdp, m);
375 	return 0;
376 }
377 
378 void
md_initm(struct mdchain * mdp,struct mbuf * m)379 md_initm(struct mdchain *mdp, struct mbuf *m)
380 {
381 	memset(mdp, 0, sizeof(*mdp));
382 	mdp->md_top = mdp->md_cur = m;
383 	mdp->md_pos = mtod(m, u_char*);
384 }
385 
386 void
md_done(struct mdchain * mdp)387 md_done(struct mdchain *mdp)
388 {
389 	if (mdp->md_top) {
390 		m_freem(mdp->md_top);
391 		mdp->md_top = NULL;
392 	}
393 }
394 
395 /*
396  * Append a separate mbuf chain. It is caller responsibility to prevent
397  * multiple calls to fetch/record routines.
398  */
399 void
md_append_record(struct mdchain * mdp,struct mbuf * top)400 md_append_record(struct mdchain *mdp, struct mbuf *top)
401 {
402 	struct mbuf *m;
403 
404 	if (mdp->md_top == NULL) {
405 		md_initm(mdp, top);
406 		return;
407 	}
408 	m = mdp->md_top;
409 	while (m->m_nextpkt)
410 		m = m->m_nextpkt;
411 	m->m_nextpkt = top;
412 	top->m_nextpkt = NULL;
413 	return;
414 }
415 
416 /*
417  * Put next record in place of existing
418  */
419 int
md_next_record(struct mdchain * mdp)420 md_next_record(struct mdchain *mdp)
421 {
422 	struct mbuf *m;
423 
424 	if (mdp->md_top == NULL)
425 		return ENOENT;
426 	m = mdp->md_top->m_nextpkt;
427 	md_done(mdp);
428 	if (m == NULL)
429 		return ENOENT;
430 	md_initm(mdp, m);
431 	return 0;
432 }
433 
434 int
md_get_uint8(struct mdchain * mdp,u_int8_t * x)435 md_get_uint8(struct mdchain *mdp, u_int8_t *x)
436 {
437 	return md_get_mem(mdp, x, 1, MB_MINLINE);
438 }
439 
440 int
md_get_uint16(struct mdchain * mdp,u_int16_t * x)441 md_get_uint16(struct mdchain *mdp, u_int16_t *x)
442 {
443 	return md_get_mem(mdp, (void *)x, 2, MB_MINLINE);
444 }
445 
446 int
md_get_uint16le(struct mdchain * mdp,u_int16_t * x)447 md_get_uint16le(struct mdchain *mdp, u_int16_t *x)
448 {
449 	u_int16_t v;
450 	int error = md_get_uint16(mdp, &v);
451 
452 	*x = le16toh(v);
453 	return error;
454 }
455 
456 int
md_get_uint16be(struct mdchain * mdp,u_int16_t * x)457 md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
458 	u_int16_t v;
459 	int error = md_get_uint16(mdp, &v);
460 
461 	*x = be16toh(v);
462 	return error;
463 }
464 
465 int
md_get_uint32(struct mdchain * mdp,u_int32_t * x)466 md_get_uint32(struct mdchain *mdp, u_int32_t *x)
467 {
468 	return md_get_mem(mdp, (void *)x, 4, MB_MINLINE);
469 }
470 
471 int
md_get_uint32be(struct mdchain * mdp,u_int32_t * x)472 md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
473 {
474 	u_int32_t v;
475 	int error;
476 
477 	error = md_get_uint32(mdp, &v);
478 	*x = be32toh(v);
479 	return error;
480 }
481 
482 int
md_get_uint32le(struct mdchain * mdp,u_int32_t * x)483 md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
484 {
485 	u_int32_t v;
486 	int error;
487 
488 	error = md_get_uint32(mdp, &v);
489 	*x = le32toh(v);
490 	return error;
491 }
492 
493 int
md_get_int64(struct mdchain * mdp,int64_t * x)494 md_get_int64(struct mdchain *mdp, int64_t *x)
495 {
496 	return md_get_mem(mdp, (void *)x, 8, MB_MINLINE);
497 }
498 
499 int
md_get_int64be(struct mdchain * mdp,int64_t * x)500 md_get_int64be(struct mdchain *mdp, int64_t *x)
501 {
502 	int64_t v;
503 	int error;
504 
505 	error = md_get_int64(mdp, &v);
506 	*x = be64toh(v);
507 	return error;
508 }
509 
510 int
md_get_int64le(struct mdchain * mdp,int64_t * x)511 md_get_int64le(struct mdchain *mdp, int64_t *x)
512 {
513 	int64_t v;
514 	int error;
515 
516 	error = md_get_int64(mdp, &v);
517 	*x = le64toh(v);
518 	return error;
519 }
520 
521 int
md_get_mem(struct mdchain * mdp,void * targetv,size_t size,int type)522 md_get_mem(struct mdchain *mdp, void *targetv, size_t size, int type)
523 {
524 	char *target = targetv;
525 	struct mbuf *m = mdp->md_cur;
526 	int error;
527 	size_t count;
528 	u_char *s;
529 
530 	while (size > 0) {
531 		if (m == NULL) {
532 #ifdef MCHAIN_DEBUG
533 			MBERROR(("incomplete copy\n"));
534 #endif
535 			return EBADRPC;
536 		}
537 		s = mdp->md_pos;
538 		count = mtod(m, u_char*) + m->m_len - s;
539 		if (count == 0) {
540 			mdp->md_cur = m = m->m_next;
541 			if (m)
542 				s = mdp->md_pos = mtod(m, void *);
543 			continue;
544 		}
545 		if (count > size)
546 			count = size;
547 		size -= count;
548 		mdp->md_pos += count;
549 		if (target == NULL)
550 			continue;
551 		switch (type) {
552 		    case MB_MUSER:
553 			error = copyout(s, target, count);
554 			if (error)
555 				return error;
556 			break;
557 		    case MB_MSYSTEM:
558 			memcpy(target, s, count);
559 			break;
560 		    case MB_MINLINE:
561 			while (count--)
562 				*target++ = *s++;
563 			continue;
564 		}
565 		target += count;
566 	}
567 	return 0;
568 }
569 
570 int
md_get_mbuf(struct mdchain * mdp,int size,struct mbuf ** ret)571 md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
572 {
573 	struct mbuf *m = mdp->md_cur, *rm;
574 
575 	rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_WAIT);
576 	if (rm == NULL)
577 		return EBADRPC;
578 	md_get_mem(mdp, NULL, size, MB_MZERO);
579 	*ret = rm;
580 	return 0;
581 }
582 
583 int
md_get_uio(struct mdchain * mdp,struct uio * uiop,size_t size)584 md_get_uio(struct mdchain *mdp, struct uio *uiop, size_t size)
585 {
586 	char *uiocp;
587 	size_t left;
588 	int mtype, error;
589 
590 	mtype = VMSPACE_IS_KERNEL_P(uiop->uio_vmspace) ? MB_MSYSTEM : MB_MUSER;
591 	while (size > 0 && uiop->uio_resid) {
592 		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
593 			return EFBIG;
594 		left = uiop->uio_iov->iov_len;
595 		if (left == 0) {
596 			uiop->uio_iov++;
597 			uiop->uio_iovcnt--;
598 			continue;
599 		}
600 		uiocp = uiop->uio_iov->iov_base;
601 		if (left > size)
602 			left = size;
603 		error = md_get_mem(mdp, uiocp, left, mtype);
604 		if (error)
605 			return error;
606 		uiop->uio_offset += left;
607 		uiop->uio_resid -= left;
608 		uiop->uio_iov->iov_base =
609 				(char *)uiop->uio_iov->iov_base + left;
610 		uiop->uio_iov->iov_len -= left;
611 		size -= left;
612 	}
613 	return 0;
614 }
615