1/*-
2 * Copyright (c) 2000, 2001 Boris Popov
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the author nor the names of any co-contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * 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/sysctl.h>
36#include <sys/endian.h>
37#include <sys/errno.h>
38#include <sys/mbuf.h>
39#include <sys/module.h>
40#include <sys/uio.h>
41
42#include <sys/mchain.h>
43
44FEATURE(libmchain, "mchain library");
45
46MODULE_VERSION(libmchain, 1);
47
48#define MBERROR(format, ...) printf("%s(%d): "format, __func__ , \
49				    __LINE__ , ## __VA_ARGS__)
50
51#define MBPANIC(format, ...) printf("%s(%d): "format, __func__ , \
52				    __LINE__ , ## __VA_ARGS__)
53
54/*
55 * Various helper functions
56 */
57int
58mb_init(struct mbchain *mbp)
59{
60	struct mbuf *m;
61
62	m = m_gethdr(M_WAITOK, MT_DATA);
63	m->m_len = 0;
64	mb_initm(mbp, m);
65	return (0);
66}
67
68void
69mb_initm(struct mbchain *mbp, struct mbuf *m)
70{
71	bzero(mbp, sizeof(*mbp));
72	mbp->mb_top = mbp->mb_cur = m;
73	mbp->mb_mleft = M_TRAILINGSPACE(m);
74}
75
76void
77mb_done(struct mbchain *mbp)
78{
79	if (mbp->mb_top) {
80		m_freem(mbp->mb_top);
81		mbp->mb_top = NULL;
82	}
83}
84
85struct mbuf *
86mb_detach(struct mbchain *mbp)
87{
88	struct mbuf *m;
89
90	m = mbp->mb_top;
91	mbp->mb_top = NULL;
92	return (m);
93}
94
95int
96mb_fixhdr(struct mbchain *mbp)
97{
98	return (mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top));
99}
100
101/*
102 * Check if object of size 'size' fit to the current position and
103 * allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
104 * Return pointer to the object placeholder or NULL if any error occured.
105 * Note: size should be <= MLEN
106 */
107caddr_t
108mb_reserve(struct mbchain *mbp, int size)
109{
110	struct mbuf *m, *mn;
111	caddr_t bpos;
112
113	if (size > MLEN)
114		panic("mb_reserve: size = %d\n", size);
115	m = mbp->mb_cur;
116	if (mbp->mb_mleft < size) {
117		mn = m_get(M_WAITOK, MT_DATA);
118		mbp->mb_cur = m->m_next = mn;
119		m = mn;
120		m->m_len = 0;
121		mbp->mb_mleft = M_TRAILINGSPACE(m);
122	}
123	mbp->mb_mleft -= size;
124	mbp->mb_count += size;
125	bpos = mtod(m, caddr_t) + m->m_len;
126	m->m_len += size;
127	return (bpos);
128}
129
130int
131mb_put_padbyte(struct mbchain *mbp)
132{
133	caddr_t dst;
134	uint8_t x = 0;
135
136	dst = mtod(mbp->mb_cur, caddr_t) + mbp->mb_cur->m_len;
137
138	/* Only add padding if address is odd */
139	if ((unsigned long)dst & 1)
140		return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
141	else
142		return (0);
143}
144
145int
146mb_put_uint8(struct mbchain *mbp, uint8_t x)
147{
148	return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
149}
150
151int
152mb_put_uint16be(struct mbchain *mbp, uint16_t x)
153{
154	x = htobe16(x);
155	return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
156}
157
158int
159mb_put_uint16le(struct mbchain *mbp, uint16_t x)
160{
161	x = htole16(x);
162	return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
163}
164
165int
166mb_put_uint32be(struct mbchain *mbp, uint32_t x)
167{
168	x = htobe32(x);
169	return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
170}
171
172int
173mb_put_uint32le(struct mbchain *mbp, uint32_t x)
174{
175	x = htole32(x);
176	return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
177}
178
179int
180mb_put_int64be(struct mbchain *mbp, int64_t x)
181{
182	x = htobe64(x);
183	return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
184}
185
186int
187mb_put_int64le(struct mbchain *mbp, int64_t x)
188{
189	x = htole64(x);
190	return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
191}
192
193int
194mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
195{
196	struct mbuf *m;
197	caddr_t dst;
198	c_caddr_t src;
199	int cplen, error, mleft, count;
200	size_t srclen, dstlen;
201
202	m = mbp->mb_cur;
203	mleft = mbp->mb_mleft;
204
205	while (size > 0) {
206		if (mleft == 0) {
207			if (m->m_next == NULL)
208				m = m_getm(m, size, M_WAITOK, MT_DATA);
209			else
210				m = m->m_next;
211			mleft = M_TRAILINGSPACE(m);
212			continue;
213		}
214		cplen = mleft > size ? size : mleft;
215		srclen = dstlen = cplen;
216		dst = mtod(m, caddr_t) + m->m_len;
217		switch (type) {
218		    case MB_MCUSTOM:
219			srclen = size;
220			dstlen = mleft;
221			error = mbp->mb_copy(mbp, source, dst, &srclen, &dstlen);
222			if (error)
223				return (error);
224			break;
225		    case MB_MINLINE:
226			for (src = source, count = cplen; count; count--)
227				*dst++ = *src++;
228			break;
229		    case MB_MSYSTEM:
230			bcopy(source, dst, cplen);
231			break;
232		    case MB_MUSER:
233			error = copyin(source, dst, cplen);
234			if (error)
235				return (error);
236			break;
237		    case MB_MZERO:
238			bzero(dst, cplen);
239			break;
240		}
241		size -= srclen;
242		source += srclen;
243		m->m_len += dstlen;
244		mleft -= dstlen;
245		mbp->mb_count += dstlen;
246	}
247	mbp->mb_cur = m;
248	mbp->mb_mleft = mleft;
249	return (0);
250}
251
252int
253mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
254{
255	mbp->mb_cur->m_next = m;
256	while (m) {
257		mbp->mb_count += m->m_len;
258		if (m->m_next == NULL)
259			break;
260		m = m->m_next;
261	}
262	mbp->mb_mleft = M_TRAILINGSPACE(m);
263	mbp->mb_cur = m;
264	return (0);
265}
266
267/*
268 * copies a uio scatter/gather list to an mbuf chain.
269 */
270int
271mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
272{
273	long left;
274	int mtype, error;
275
276	mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
277
278	while (size > 0 && uiop->uio_resid) {
279		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
280			return (EFBIG);
281		left = uiop->uio_iov->iov_len;
282		if (left == 0) {
283			uiop->uio_iov++;
284			uiop->uio_iovcnt--;
285			continue;
286		}
287		if (left > size)
288			left = size;
289		error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
290		if (error)
291			return (error);
292		uiop->uio_offset += left;
293		uiop->uio_resid -= left;
294		uiop->uio_iov->iov_base =
295		    (char *)uiop->uio_iov->iov_base + left;
296		uiop->uio_iov->iov_len -= left;
297		size -= left;
298	}
299	return (0);
300}
301
302/*
303 * Routines for fetching data from an mbuf chain
304 */
305int
306md_init(struct mdchain *mdp)
307{
308	struct mbuf *m;
309
310	m = m_gethdr(M_WAITOK, MT_DATA);
311	m->m_len = 0;
312	md_initm(mdp, m);
313	return (0);
314}
315
316void
317md_initm(struct mdchain *mdp, struct mbuf *m)
318{
319	bzero(mdp, sizeof(*mdp));
320	mdp->md_top = mdp->md_cur = m;
321	mdp->md_pos = mtod(m, u_char*);
322}
323
324void
325md_done(struct mdchain *mdp)
326{
327	if (mdp->md_top) {
328		m_freem(mdp->md_top);
329		mdp->md_top = NULL;
330	}
331}
332
333/*
334 * Append a separate mbuf chain. It is caller responsibility to prevent
335 * multiple calls to fetch/record routines.
336 */
337void
338md_append_record(struct mdchain *mdp, struct mbuf *top)
339{
340	struct mbuf *m;
341
342	if (mdp->md_top == NULL) {
343		md_initm(mdp, top);
344		return;
345	}
346	m = mdp->md_top;
347	while (m->m_nextpkt)
348		m = m->m_nextpkt;
349	m->m_nextpkt = top;
350	top->m_nextpkt = NULL;
351	return;
352}
353
354/*
355 * Put next record in place of existing
356 */
357int
358md_next_record(struct mdchain *mdp)
359{
360	struct mbuf *m;
361
362	if (mdp->md_top == NULL)
363		return (ENOENT);
364	m = mdp->md_top->m_nextpkt;
365	md_done(mdp);
366	if (m == NULL)
367		return (ENOENT);
368	md_initm(mdp, m);
369	return (0);
370}
371
372int
373md_get_uint8(struct mdchain *mdp, uint8_t *x)
374{
375	return (md_get_mem(mdp, x, 1, MB_MINLINE));
376}
377
378int
379md_get_uint16(struct mdchain *mdp, uint16_t *x)
380{
381	return (md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE));
382}
383
384int
385md_get_uint16le(struct mdchain *mdp, uint16_t *x)
386{
387	uint16_t v;
388	int error = md_get_uint16(mdp, &v);
389
390	if (x != NULL)
391		*x = le16toh(v);
392	return (error);
393}
394
395int
396md_get_uint16be(struct mdchain *mdp, uint16_t *x)
397{
398	uint16_t v;
399	int error = md_get_uint16(mdp, &v);
400
401	if (x != NULL)
402		*x = be16toh(v);
403	return (error);
404}
405
406int
407md_get_uint32(struct mdchain *mdp, uint32_t *x)
408{
409	return (md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE));
410}
411
412int
413md_get_uint32be(struct mdchain *mdp, uint32_t *x)
414{
415	uint32_t v;
416	int error;
417
418	error = md_get_uint32(mdp, &v);
419	if (x != NULL)
420		*x = be32toh(v);
421	return (error);
422}
423
424int
425md_get_uint32le(struct mdchain *mdp, uint32_t *x)
426{
427	uint32_t v;
428	int error;
429
430	error = md_get_uint32(mdp, &v);
431	if (x != NULL)
432		*x = le32toh(v);
433	return (error);
434}
435
436int
437md_get_int64(struct mdchain *mdp, int64_t *x)
438{
439	return (md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE));
440}
441
442int
443md_get_int64be(struct mdchain *mdp, int64_t *x)
444{
445	int64_t v;
446	int error;
447
448	error = md_get_int64(mdp, &v);
449	if (x != NULL)
450		*x = be64toh(v);
451	return (error);
452}
453
454int
455md_get_int64le(struct mdchain *mdp, int64_t *x)
456{
457	int64_t v;
458	int error;
459
460	error = md_get_int64(mdp, &v);
461	if (x != NULL)
462		*x = le64toh(v);
463	return (error);
464}
465
466int
467md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
468{
469	struct mbuf *m = mdp->md_cur;
470	int error;
471	u_int count;
472	u_char *s;
473
474	while (size > 0) {
475		if (m == NULL) {
476			MBERROR("incomplete copy\n");
477			return (EBADRPC);
478		}
479		s = mdp->md_pos;
480		count = mtod(m, u_char*) + m->m_len - s;
481		if (count == 0) {
482			mdp->md_cur = m = m->m_next;
483			if (m)
484				s = mdp->md_pos = mtod(m, caddr_t);
485			continue;
486		}
487		if (count > size)
488			count = size;
489		size -= count;
490		mdp->md_pos += count;
491		if (target == NULL)
492			continue;
493		switch (type) {
494		    case MB_MUSER:
495			error = copyout(s, target, count);
496			if (error)
497				return error;
498			break;
499		    case MB_MSYSTEM:
500			bcopy(s, target, count);
501			break;
502		    case MB_MINLINE:
503			while (count--)
504				*target++ = *s++;
505			continue;
506		}
507		target += count;
508	}
509	return (0);
510}
511
512int
513md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
514{
515	struct mbuf *m = mdp->md_cur, *rm;
516
517	rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_WAITOK);
518	md_get_mem(mdp, NULL, size, MB_MZERO);
519	*ret = rm;
520	return (0);
521}
522
523int
524md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
525{
526	char *uiocp;
527	long left;
528	int mtype, error;
529
530	mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
531	while (size > 0 && uiop->uio_resid) {
532		if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
533			return (EFBIG);
534		left = uiop->uio_iov->iov_len;
535		if (left == 0) {
536			uiop->uio_iov++;
537			uiop->uio_iovcnt--;
538			continue;
539		}
540		uiocp = uiop->uio_iov->iov_base;
541		if (left > size)
542			left = size;
543		error = md_get_mem(mdp, uiocp, left, mtype);
544		if (error)
545			return (error);
546		uiop->uio_offset += left;
547		uiop->uio_resid -= left;
548		uiop->uio_iov->iov_base =
549		    (char *)uiop->uio_iov->iov_base + left;
550		uiop->uio_iov->iov_len -= left;
551		size -= left;
552	}
553	return (0);
554}
555