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