sys/kern/libmchain/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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *    This product includes software developed by Boris Popov.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/sys/kern/subr_mchain.c,v 1.2.2.2 2002/04/13 12:46:40 bp Exp $
  33  * $DragonFly: src/sys/kern/libmchain/subr_mchain.c,v 1.6 2007/10/20 09:38:01 sephe Exp $
  34  */
  35
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/kernel.h>
  40 #include <sys/errno.h>
  41 #include <sys/malloc.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/module.h>
  44 #include <sys/uio.h>
  45
  46 #include <sys/mchain.h>
  47
  48 MODULE_VERSION(libmchain, 1);
  49
  50 #define MBERROR(format, args...) kprintf("%s(%d): "format, __func__ , \
  51                                     __LINE__ ,## args)
  52
  53 #define MBPANIC(format, args...) kprintf("%s(%d): "format, __func__ , \
  54                                     __LINE__ ,## args)
  55
  56 /*
  57  * Various helper functions
  58  */
  59 int
  60 m_fixhdr(struct mbuf *m0)
  61 {
  62         struct mbuf *m = m0;
  63         int len = 0;
  64
  65         while (m) {
  66                 len += m->m_len;
  67                 m = m->m_next;
  68         }
  69         m0->m_pkthdr.len = len;
  70         return len;
  71 }
  72
  73 int
  74 mb_init(struct mbchain *mbp)
  75 {
  76         struct mbuf *m;
  77
  78         m = m_gethdr(MB_WAIT, MT_DATA);
  79         if (m == NULL)
  80                 return ENOBUFS;
  81         m->m_pkthdr.rcvif = NULL;
  82         m->m_len = 0;
  83         mb_initm(mbp, m);
  84         return 0;
  85 }
  86
  87 void
  88 mb_initm(struct mbchain *mbp, struct mbuf *m)
  89 {
  90         bzero(mbp, sizeof(*mbp));
  91         mbp->mb_top = mbp->mb_cur = m;
  92         mbp->mb_mleft = M_TRAILINGSPACE(m);
  93 }
  94
  95 void
  96 mb_done(struct mbchain *mbp)
  97 {
  98         if (mbp->mb_top) {
  99                 m_freem(mbp->mb_top);
 100                 mbp->mb_top = NULL;
 101         }
 102 }
 103
 104 struct mbuf *
 105 mb_detach(struct mbchain *mbp)
 106 {
 107         struct mbuf *m;
 108
 109         m = mbp->mb_top;
 110         mbp->mb_top = NULL;
 111         return m;
 112 }
 113
 114 int
 115 mb_fixhdr(struct mbchain *mbp)
 116 {
 117         return mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top);
 118 }
 119
 120 /*
 121  * Check if object of size 'size' fit to the current position and
 122  * allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
 123  * Return pointer to the object placeholder or NULL if any error occured.
 124  * Note: size should be <= MLEN
 125  */
 126 caddr_t
 127 mb_reserve(struct mbchain *mbp, int size)
 128 {
 129         struct mbuf *m, *mn;
 130         caddr_t bpos;
 131
 132         if (size > MLEN)
 133                 panic("mb_reserve: size = %d\n", size);
 134         m = mbp->mb_cur;
 135         if (mbp->mb_mleft < size) {
 136                 mn = m_get(MB_WAIT, MT_DATA);
 137                 if (mn == NULL)
 138                         return NULL;
 139                 mbp->mb_cur = m->m_next = mn;
 140                 m = mn;
 141                 m->m_len = 0;
 142                 mbp->mb_mleft = M_TRAILINGSPACE(m);
 143         }
 144         mbp->mb_mleft -= size;
 145         mbp->mb_count += size;
 146         bpos = mtod(m, caddr_t) + m->m_len;
 147         m->m_len += size;
 148         return bpos;
 149 }
 150
 151 int
 152 mb_put_uint8(struct mbchain *mbp, u_int8_t x)
 153 {
 154         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 155 }
 156
 157 int
 158 mb_put_uint16be(struct mbchain *mbp, u_int16_t x)
 159 {
 160         x = htobes(x);
 161         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 162 }
 163
 164 int
 165 mb_put_uint16le(struct mbchain *mbp, u_int16_t x)
 166 {
 167         x = htoles(x);
 168         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 169 }
 170
 171 int
 172 mb_put_uint32be(struct mbchain *mbp, u_int32_t x)
 173 {
 174         x = htobel(x);
 175         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 176 }
 177
 178 int
 179 mb_put_uint32le(struct mbchain *mbp, u_int32_t x)
 180 {
 181         x = htolel(x);
 182         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 183 }
 184
 185 int
 186 mb_put_int64be(struct mbchain *mbp, int64_t x)
 187 {
 188         x = htobeq(x);
 189         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 190 }
 191
 192 int
 193 mb_put_int64le(struct mbchain *mbp, int64_t x)
 194 {
 195         x = htoleq(x);
 196         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 197 }
 198
 199 int
 200 mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
 201 {
 202         struct mbuf *m;
 203         caddr_t dst;
 204         c_caddr_t src;
 205         int error, mleft, count;
 206         size_t cplen;
 207
 208         m = mbp->mb_cur;
 209         mleft = mbp->mb_mleft;
 210
 211         while (size > 0) {
 212                 if (mleft == 0) {
 213                         if (m->m_next == NULL) {
 214                                 m->m_next = m_getc(size, MB_WAIT, MT_DATA);
 215                                 if (m == NULL)
 216                                         return ENOBUFS;
 217                         }
 218                         m = m->m_next;
 219                         mleft = M_TRAILINGSPACE(m);
 220                         continue;
 221                 }
 222                 cplen = mleft > size ? size : mleft;
 223                 dst = mtod(m, caddr_t) + m->m_len;
 224                 switch (type) {
 225                     case MB_MCUSTOM:
 226                         error = mbp->mb_copy(mbp, source, dst, cplen);
 227                         if (error)
 228                                 return error;
 229                         break;
 230                     case MB_MINLINE:
 231                         for (src = source, count = cplen; count; count--)
 232                                 *dst++ = *src++;
 233                         break;
 234                     case MB_MSYSTEM:
 235                         bcopy(source, dst, cplen);
 236                         break;
 237                     case MB_MUSER:
 238                         error = copyin(source, dst, cplen);
 239                         if (error)
 240                                 return error;
 241                         break;
 242                     case MB_MZERO:
 243                         bzero(dst, cplen);
 244                         break;
 245                 }
 246                 size -= cplen;
 247                 source += cplen;
 248                 m->m_len += cplen;
 249                 mleft -= cplen;
 250                 mbp->mb_count += cplen;
 251         }
 252         mbp->mb_cur = m;
 253         mbp->mb_mleft = mleft;
 254         return 0;
 255 }
 256
 257 int
 258 mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
 259 {
 260         mbp->mb_cur->m_next = m;
 261         while (m) {
 262                 mbp->mb_count += m->m_len;
 263                 if (m->m_next == NULL)
 264                         break;
 265                 m = m->m_next;
 266         }
 267         mbp->mb_mleft = M_TRAILINGSPACE(m);
 268         mbp->mb_cur = m;
 269         return 0;
 270 }
 271
 272 /*
 273  * copies a uio scatter/gather list to an mbuf chain.
 274  */
 275 int
 276 mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
 277 {
 278         long left;
 279         int mtype, error;
 280
 281         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
 282
 283         while (size > 0 && uiop->uio_resid) {
 284                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
 285                         return EFBIG;
 286                 left = uiop->uio_iov->iov_len;
 287                 if (left == 0) {
 288                         uiop->uio_iov++;
 289                         uiop->uio_iovcnt--;
 290                         continue;
 291                 }
 292                 if (left > size)
 293                         left = size;
 294                 error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
 295                 if (error)
 296                         return error;
 297                 uiop->uio_offset += left;
 298                 uiop->uio_resid -= left;
 299                 uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + left;
 300                 uiop->uio_iov->iov_len -= left;
 301                 size -= left;
 302         }
 303         return 0;
 304 }
 305
 306 /*
 307  * Routines for fetching data from an mbuf chain
 308  */
 309 int
 310 md_init(struct mdchain *mdp)
 311 {
 312         struct mbuf *m;
 313
 314         m = m_gethdr(MB_WAIT, MT_DATA);
 315         if (m == NULL)
 316                 return ENOBUFS;
 317         m->m_pkthdr.rcvif = NULL;
 318         m->m_len = 0;
 319         md_initm(mdp, m);
 320         return 0;
 321 }
 322
 323 void
 324 md_initm(struct mdchain *mdp, struct mbuf *m)
 325 {
 326         bzero(mdp, sizeof(*mdp));
 327         mdp->md_top = mdp->md_cur = m;
 328         mdp->md_pos = mtod(m, u_char*);
 329 }
 330
 331 void
 332 md_done(struct mdchain *mdp)
 333 {
 334         if (mdp->md_top) {
 335                 m_freem(mdp->md_top);
 336                 mdp->md_top = NULL;
 337         }
 338 }
 339
 340 /*
 341  * Append a separate mbuf chain. It is caller responsibility to prevent
 342  * multiple calls to fetch/record routines.
 343  */
 344 void
 345 md_append_record(struct mdchain *mdp, struct mbuf *top)
 346 {
 347         struct mbuf *m;
 348
 349         if (mdp->md_top == NULL) {
 350                 md_initm(mdp, top);
 351                 return;
 352         }
 353         m = mdp->md_top;
 354         while (m->m_nextpkt)
 355                 m = m->m_nextpkt;
 356         m->m_nextpkt = top;
 357         top->m_nextpkt = NULL;
 358         return;
 359 }
 360
 361 /*
 362  * Put next record in place of existing
 363  */
 364 int
 365 md_next_record(struct mdchain *mdp)
 366 {
 367         struct mbuf *m;
 368
 369         if (mdp->md_top == NULL)
 370                 return ENOENT;
 371         m = mdp->md_top->m_nextpkt;
 372         md_done(mdp);
 373         if (m == NULL)
 374                 return ENOENT;
 375         md_initm(mdp, m);
 376         return 0;
 377 }
 378
 379 int
 380 md_get_uint8(struct mdchain *mdp, u_int8_t *x)
 381 {
 382         return md_get_mem(mdp, x, 1, MB_MINLINE);
 383 }
 384
 385 int
 386 md_get_uint16(struct mdchain *mdp, u_int16_t *x)
 387 {
 388         return md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE);
 389 }
 390
 391 int
 392 md_get_uint16le(struct mdchain *mdp, u_int16_t *x)
 393 {
 394         u_int16_t v;
 395         int error = md_get_uint16(mdp, &v);
 396
 397         *x = letohs(v);
 398         return error;
 399 }
 400
 401 int
 402 md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
 403         u_int16_t v;
 404         int error = md_get_uint16(mdp, &v);
 405
 406         *x = betohs(v);
 407         return error;
 408 }
 409
 410 int
 411 md_get_uint32(struct mdchain *mdp, u_int32_t *x)
 412 {
 413         return md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE);
 414 }
 415
 416 int
 417 md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
 418 {
 419         u_int32_t v;
 420         int error;
 421
 422         error = md_get_uint32(mdp, &v);
 423         *x = betohl(v);
 424         return error;
 425 }
 426
 427 int
 428 md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
 429 {
 430         u_int32_t v;
 431         int error;
 432
 433         error = md_get_uint32(mdp, &v);
 434         *x = letohl(v);
 435         return error;
 436 }
 437
 438 int
 439 md_get_int64(struct mdchain *mdp, int64_t *x)
 440 {
 441         return md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE);
 442 }
 443
 444 int
 445 md_get_int64be(struct mdchain *mdp, int64_t *x)
 446 {
 447         int64_t v;
 448         int error;
 449
 450         error = md_get_int64(mdp, &v);
 451         *x = betohq(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         *x = letohq(v);
 463         return error;
 464 }
 465
 466 int
 467 md_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
 512 int
 513 md_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, MB_WAIT);
 518         if (rm == NULL)
 519                 return EBADRPC;
 520         md_get_mem(mdp, NULL, size, MB_MZERO);
 521         *ret = rm;
 522         return 0;
 523 }
 524
 525 int
 526 md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
 527 {
 528         char *uiocp;
 529         long left;
 530         int mtype, error;
 531
 532         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
 533         while (size > 0 && uiop->uio_resid) {
 534                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
 535                         return EFBIG;
 536                 left = uiop->uio_iov->iov_len;
 537                 if (left == 0) {
 538                         uiop->uio_iov++;
 539                         uiop->uio_iovcnt--;
 540                         continue;
 541                 }
 542                 uiocp = uiop->uio_iov->iov_base;
 543                 if (left > size)
 544                         left = size;
 545                 error = md_get_mem(mdp, uiocp, left, mtype);
 546                 if (error)
 547                         return error;
 548                 uiop->uio_offset += left;
 549                 uiop->uio_resid -= left;
 550                 uiop->uio_iov->iov_base = (char *)uiop->uio_iov->iov_base + left;
 551                 uiop->uio_iov->iov_len -= left;
 552                 size -= left;
 553         }
 554         return 0;
 555 }