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: releng/7.4/sys/kern/subr_mchain.c 148517 2005-07-29 13:22:37Z imura $");
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/endian.h>
36 #include <sys/errno.h>
37 #include <sys/mbuf.h>
38 #include <sys/module.h>
39 #include <sys/uio.h>
40
41 #include <sys/mchain.h>
42
43 MODULE_VERSION(libmchain, 1);
44
45 #define MBERROR(format, ...) printf("%s(%d): "format, __func__ , \
46 __LINE__ , ## __VA_ARGS__)
47
48 #define MBPANIC(format, ...) printf("%s(%d): "format, __func__ , \
49 __LINE__ , ## __VA_ARGS__)
50
51 /*
52 * Various helper functions
53 */
54 int
55 mb_init(struct mbchain *mbp)
56 {
57 struct mbuf *m;
58
59 m = m_gethdr(M_TRYWAIT, MT_DATA);
60 if (m == NULL)
61 return ENOBUFS;
62 m->m_len = 0;
63 mb_initm(mbp, m);
64 return 0;
65 }
66
67 void
68 mb_initm(struct mbchain *mbp, struct mbuf *m)
69 {
70 bzero(mbp, sizeof(*mbp));
71 mbp->mb_top = mbp->mb_cur = m;
72 mbp->mb_mleft = M_TRAILINGSPACE(m);
73 }
74
75 void
76 mb_done(struct mbchain *mbp)
77 {
78 if (mbp->mb_top) {
79 m_freem(mbp->mb_top);
80 mbp->mb_top = NULL;
81 }
82 }
83
84 struct mbuf *
85 mb_detach(struct mbchain *mbp)
86 {
87 struct mbuf *m;
88
89 m = mbp->mb_top;
90 mbp->mb_top = NULL;
91 return m;
92 }
93
94 int
95 mb_fixhdr(struct mbchain *mbp)
96 {
97 return mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top);
98 }
99
100 /*
101 * Check if object of size 'size' fit to the current position and
102 * allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
103 * Return pointer to the object placeholder or NULL if any error occured.
104 * Note: size should be <= MLEN
105 */
106 caddr_t
107 mb_reserve(struct mbchain *mbp, int size)
108 {
109 struct mbuf *m, *mn;
110 caddr_t bpos;
111
112 if (size > MLEN)
113 panic("mb_reserve: size = %d\n", size);
114 m = mbp->mb_cur;
115 if (mbp->mb_mleft < size) {
116 mn = m_get(M_TRYWAIT, MT_DATA);
117 if (mn == NULL)
118 return NULL;
119 mbp->mb_cur = m->m_next = mn;
120 m = mn;
121 m->m_len = 0;
122 mbp->mb_mleft = M_TRAILINGSPACE(m);
123 }
124 mbp->mb_mleft -= size;
125 mbp->mb_count += size;
126 bpos = mtod(m, caddr_t) + m->m_len;
127 m->m_len += size;
128 return bpos;
129 }
130
131 int
132 mb_put_uint8(struct mbchain *mbp, u_int8_t x)
133 {
134 return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
135 }
136
137 int
138 mb_put_uint16be(struct mbchain *mbp, u_int16_t x)
139 {
140 x = htobe16(x);
141 return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
142 }
143
144 int
145 mb_put_uint16le(struct mbchain *mbp, u_int16_t x)
146 {
147 x = htole16(x);
148 return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
149 }
150
151 int
152 mb_put_uint32be(struct mbchain *mbp, u_int32_t x)
153 {
154 x = htobe32(x);
155 return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
156 }
157
158 int
159 mb_put_uint32le(struct mbchain *mbp, u_int32_t x)
160 {
161 x = htole32(x);
162 return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
163 }
164
165 int
166 mb_put_int64be(struct mbchain *mbp, int64_t x)
167 {
168 x = htobe64(x);
169 return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
170 }
171
172 int
173 mb_put_int64le(struct mbchain *mbp, int64_t x)
174 {
175 x = htole64(x);
176 return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
177 }
178
179 int
180 mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
181 {
182 struct mbuf *m;
183 caddr_t dst;
184 c_caddr_t src;
185 int cplen, error, mleft, count;
186 size_t srclen, dstlen;
187
188 m = mbp->mb_cur;
189 mleft = mbp->mb_mleft;
190
191 while (size > 0) {
192 if (mleft == 0) {
193 if (m->m_next == NULL) {
194 m = m_getm(m, size, M_TRYWAIT, MT_DATA);
195 if (m == NULL)
196 return ENOBUFS;
197 } else
198 m = m->m_next;
199 mleft = M_TRAILINGSPACE(m);
200 continue;
201 }
202 cplen = mleft > size ? size : mleft;
203 srclen = dstlen = cplen;
204 dst = mtod(m, caddr_t) + m->m_len;
205 switch (type) {
206 case MB_MCUSTOM:
207 srclen = size;
208 dstlen = mleft;
209 error = mbp->mb_copy(mbp, source, dst, &srclen, &dstlen);
210 if (error)
211 return error;
212 break;
213 case MB_MINLINE:
214 for (src = source, count = cplen; count; count--)
215 *dst++ = *src++;
216 break;
217 case MB_MSYSTEM:
218 bcopy(source, dst, cplen);
219 break;
220 case MB_MUSER:
221 error = copyin(source, dst, cplen);
222 if (error)
223 return error;
224 break;
225 case MB_MZERO:
226 bzero(dst, cplen);
227 break;
228 }
229 size -= srclen;
230 source += srclen;
231 m->m_len += dstlen;
232 mleft -= dstlen;
233 mbp->mb_count += dstlen;
234 }
235 mbp->mb_cur = m;
236 mbp->mb_mleft = mleft;
237 return 0;
238 }
239
240 int
241 mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
242 {
243 mbp->mb_cur->m_next = m;
244 while (m) {
245 mbp->mb_count += m->m_len;
246 if (m->m_next == NULL)
247 break;
248 m = m->m_next;
249 }
250 mbp->mb_mleft = M_TRAILINGSPACE(m);
251 mbp->mb_cur = m;
252 return 0;
253 }
254
255 /*
256 * copies a uio scatter/gather list to an mbuf chain.
257 */
258 int
259 mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
260 {
261 long left;
262 int mtype, error;
263
264 mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
265
266 while (size > 0 && uiop->uio_resid) {
267 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
268 return EFBIG;
269 left = uiop->uio_iov->iov_len;
270 if (left == 0) {
271 uiop->uio_iov++;
272 uiop->uio_iovcnt--;
273 continue;
274 }
275 if (left > size)
276 left = size;
277 error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
278 if (error)
279 return error;
280 uiop->uio_offset += left;
281 uiop->uio_resid -= left;
282 uiop->uio_iov->iov_base =
283 (char *)uiop->uio_iov->iov_base + left;
284 uiop->uio_iov->iov_len -= left;
285 size -= left;
286 }
287 return 0;
288 }
289
290 /*
291 * Routines for fetching data from an mbuf chain
292 */
293 int
294 md_init(struct mdchain *mdp)
295 {
296 struct mbuf *m;
297
298 m = m_gethdr(M_TRYWAIT, MT_DATA);
299 if (m == NULL)
300 return ENOBUFS;
301 m->m_len = 0;
302 md_initm(mdp, m);
303 return 0;
304 }
305
306 void
307 md_initm(struct mdchain *mdp, struct mbuf *m)
308 {
309 bzero(mdp, sizeof(*mdp));
310 mdp->md_top = mdp->md_cur = m;
311 mdp->md_pos = mtod(m, u_char*);
312 }
313
314 void
315 md_done(struct mdchain *mdp)
316 {
317 if (mdp->md_top) {
318 m_freem(mdp->md_top);
319 mdp->md_top = NULL;
320 }
321 }
322
323 /*
324 * Append a separate mbuf chain. It is caller responsibility to prevent
325 * multiple calls to fetch/record routines.
326 */
327 void
328 md_append_record(struct mdchain *mdp, struct mbuf *top)
329 {
330 struct mbuf *m;
331
332 if (mdp->md_top == NULL) {
333 md_initm(mdp, top);
334 return;
335 }
336 m = mdp->md_top;
337 while (m->m_nextpkt)
338 m = m->m_nextpkt;
339 m->m_nextpkt = top;
340 top->m_nextpkt = NULL;
341 return;
342 }
343
344 /*
345 * Put next record in place of existing
346 */
347 int
348 md_next_record(struct mdchain *mdp)
349 {
350 struct mbuf *m;
351
352 if (mdp->md_top == NULL)
353 return ENOENT;
354 m = mdp->md_top->m_nextpkt;
355 md_done(mdp);
356 if (m == NULL)
357 return ENOENT;
358 md_initm(mdp, m);
359 return 0;
360 }
361
362 int
363 md_get_uint8(struct mdchain *mdp, u_int8_t *x)
364 {
365 return md_get_mem(mdp, x, 1, MB_MINLINE);
366 }
367
368 int
369 md_get_uint16(struct mdchain *mdp, u_int16_t *x)
370 {
371 return md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE);
372 }
373
374 int
375 md_get_uint16le(struct mdchain *mdp, u_int16_t *x)
376 {
377 u_int16_t v;
378 int error = md_get_uint16(mdp, &v);
379
380 if (x != NULL)
381 *x = le16toh(v);
382 return error;
383 }
384
385 int
386 md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
387 u_int16_t v;
388 int error = md_get_uint16(mdp, &v);
389
390 if (x != NULL)
391 *x = be16toh(v);
392 return error;
393 }
394
395 int
396 md_get_uint32(struct mdchain *mdp, u_int32_t *x)
397 {
398 return md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE);
399 }
400
401 int
402 md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
403 {
404 u_int32_t v;
405 int error;
406
407 error = md_get_uint32(mdp, &v);
408 if (x != NULL)
409 *x = be32toh(v);
410 return error;
411 }
412
413 int
414 md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
415 {
416 u_int32_t v;
417 int error;
418
419 error = md_get_uint32(mdp, &v);
420 if (x != NULL)
421 *x = le32toh(v);
422 return error;
423 }
424
425 int
426 md_get_int64(struct mdchain *mdp, int64_t *x)
427 {
428 return md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE);
429 }
430
431 int
432 md_get_int64be(struct mdchain *mdp, int64_t *x)
433 {
434 int64_t v;
435 int error;
436
437 error = md_get_int64(mdp, &v);
438 if (x != NULL)
439 *x = be64toh(v);
440 return error;
441 }
442
443 int
444 md_get_int64le(struct mdchain *mdp, int64_t *x)
445 {
446 int64_t v;
447 int error;
448
449 error = md_get_int64(mdp, &v);
450 if (x != NULL)
451 *x = le64toh(v);
452 return error;
453 }
454
455 int
456 md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
457 {
458 struct mbuf *m = mdp->md_cur;
459 int error;
460 u_int count;
461 u_char *s;
462
463 while (size > 0) {
464 if (m == NULL) {
465 MBERROR("incomplete copy\n");
466 return EBADRPC;
467 }
468 s = mdp->md_pos;
469 count = mtod(m, u_char*) + m->m_len - s;
470 if (count == 0) {
471 mdp->md_cur = m = m->m_next;
472 if (m)
473 s = mdp->md_pos = mtod(m, caddr_t);
474 continue;
475 }
476 if (count > size)
477 count = size;
478 size -= count;
479 mdp->md_pos += count;
480 if (target == NULL)
481 continue;
482 switch (type) {
483 case MB_MUSER:
484 error = copyout(s, target, count);
485 if (error)
486 return error;
487 break;
488 case MB_MSYSTEM:
489 bcopy(s, target, count);
490 break;
491 case MB_MINLINE:
492 while (count--)
493 *target++ = *s++;
494 continue;
495 }
496 target += count;
497 }
498 return 0;
499 }
500
501 int
502 md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
503 {
504 struct mbuf *m = mdp->md_cur, *rm;
505
506 rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_TRYWAIT);
507 if (rm == NULL)
508 return EBADRPC;
509 md_get_mem(mdp, NULL, size, MB_MZERO);
510 *ret = rm;
511 return 0;
512 }
513
514 int
515 md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
516 {
517 char *uiocp;
518 long left;
519 int mtype, error;
520
521 mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
522 while (size > 0 && uiop->uio_resid) {
523 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
524 return EFBIG;
525 left = uiop->uio_iov->iov_len;
526 if (left == 0) {
527 uiop->uio_iov++;
528 uiop->uio_iovcnt--;
529 continue;
530 }
531 uiocp = uiop->uio_iov->iov_base;
532 if (left > size)
533 left = size;
534 error = md_get_mem(mdp, uiocp, left, mtype);
535 if (error)
536 return error;
537 uiop->uio_offset += left;
538 uiop->uio_resid -= left;
539 uiop->uio_iov->iov_base =
540 (char *)uiop->uio_iov->iov_base + left;
541 uiop->uio_iov->iov_len -= left;
542 size -= left;
543 }
544 return 0;
545 }
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