sys/kern/subr_mchain.c

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