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  * 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  * $FreeBSD: src/sys/kern/subr_mchain.c,v 1.2.2.2 2002/04/13 12:46:40 bp Exp $
  30  */
  31
  32
  33 #include <sys/param.h>
  34 #include <sys/systm.h>
  35 #include <sys/kernel.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
  44 MODULE_VERSION(libmchain, 1);
  45
  46 #define MBERROR(format, ...) kprintf("%s(%d): "format, __func__ , \
  47                                     __LINE__ , ## __VA_ARGS__)
  48
  49 #define MBPANIC(format, ...) kprintf("%s(%d): "format, __func__ , \
  50                                     __LINE__ , ## __VA_ARGS__)
  51
  52 /*
  53  * Various helper functions
  54  */
  55 int
  56 m_fixhdr(struct mbuf *m0)
  57 {
  58         struct mbuf *m = m0;
  59         int len = 0;
  60
  61         while (m) {
  62                 len += m->m_len;
  63                 m = m->m_next;
  64         }
  65         m0->m_pkthdr.len = len;
  66         return len;
  67 }
  68
  69 int
  70 mb_init(struct mbchain *mbp)
  71 {
  72         struct mbuf *m;
  73
  74         m = m_gethdr(M_WAITOK, MT_DATA);
  75         if (m == NULL)
  76                 return ENOBUFS;
  77         m->m_pkthdr.rcvif = NULL;
  78         m->m_len = 0;
  79         mb_initm(mbp, m);
  80         return 0;
  81 }
  82
  83 void
  84 mb_initm(struct mbchain *mbp, struct mbuf *m)
  85 {
  86         bzero(mbp, sizeof(*mbp));
  87         mbp->mb_top = mbp->mb_cur = m;
  88         mbp->mb_mleft = M_TRAILINGSPACE(m);
  89 }
  90
  91 void
  92 mb_done(struct mbchain *mbp)
  93 {
  94         if (mbp->mb_top) {
  95                 m_freem(mbp->mb_top);
  96                 mbp->mb_top = NULL;
  97         }
  98 }
  99
 100 struct mbuf *
 101 mb_detach(struct mbchain *mbp)
 102 {
 103         struct mbuf *m;
 104
 105         m = mbp->mb_top;
 106         mbp->mb_top = NULL;
 107         return m;
 108 }
 109
 110 int
 111 mb_fixhdr(struct mbchain *mbp)
 112 {
 113         return mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top);
 114 }
 115
 116 /*
 117  * Check if object of size 'size' fit to the current position and
 118  * allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
 119  * Return pointer to the object placeholder or NULL if any error occured.
 120  * Note: size should be <= MLEN
 121  */
 122 caddr_t
 123 mb_reserve(struct mbchain *mbp, int size)
 124 {
 125         struct mbuf *m, *mn;
 126         caddr_t bpos;
 127
 128         if (size > MLEN)
 129                 panic("mb_reserve: size = %d", size);
 130         m = mbp->mb_cur;
 131         if (mbp->mb_mleft < size) {
 132                 mn = m_get(M_WAITOK, MT_DATA);
 133                 if (mn == NULL)
 134                         return NULL;
 135                 mbp->mb_cur = m->m_next = mn;
 136                 m = mn;
 137                 m->m_len = 0;
 138                 mbp->mb_mleft = M_TRAILINGSPACE(m);
 139         }
 140         mbp->mb_mleft -= size;
 141         mbp->mb_count += size;
 142         bpos = mtod(m, caddr_t) + m->m_len;
 143         m->m_len += size;
 144         return bpos;
 145 }
 146
 147 int
 148 mb_put_uint8(struct mbchain *mbp, u_int8_t x)
 149 {
 150         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 151 }
 152
 153 int
 154 mb_put_uint16be(struct mbchain *mbp, u_int16_t x)
 155 {
 156         x = htobe16(x);
 157         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 158 }
 159
 160 int
 161 mb_put_uint16le(struct mbchain *mbp, u_int16_t x)
 162 {
 163         x = htole16(x);
 164         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 165 }
 166
 167 int
 168 mb_put_uint32be(struct mbchain *mbp, u_int32_t x)
 169 {
 170         x = htobe32(x);
 171         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 172 }
 173
 174 int
 175 mb_put_uint32le(struct mbchain *mbp, u_int32_t x)
 176 {
 177         x = htole32(x);
 178         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 179 }
 180
 181 int
 182 mb_put_int64be(struct mbchain *mbp, int64_t x)
 183 {
 184         x = htobe64(x);
 185         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 186 }
 187
 188 int
 189 mb_put_int64le(struct mbchain *mbp, int64_t x)
 190 {
 191         x = htole64(x);
 192         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
 193 }
 194
 195 int
 196 mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
 197 {
 198         struct mbuf *m;
 199         caddr_t dst;
 200         c_caddr_t src;
 201         int error, mleft, count;
 202         size_t cplen, srclen, dstlen;
 203
 204         m = mbp->mb_cur;
 205         mleft = mbp->mb_mleft;
 206
 207         while (size > 0) {
 208                 if (mleft == 0) {
 209                         if (m->m_next == NULL) {
 210                                 m->m_next = m_getc(size, M_WAITOK, MT_DATA);
 211                                 if (m->m_next == NULL)
 212                                         return ENOBUFS;
 213                         }
 214                         m = m->m_next;
 215                         mleft = M_TRAILINGSPACE(m);
 216                         continue;
 217                 }
 218                 cplen = mleft > size ? size : mleft;
 219                 srclen = dstlen = cplen;
 220                 dst = mtod(m, caddr_t) + m->m_len;
 221                 switch (type) {
 222                     case MB_MCUSTOM:
 223                         srclen = size;
 224                         dstlen = mleft;
 225                         error = mbp->mb_copy(mbp, source, dst, &srclen, &dstlen);
 226                         if (error)
 227                                 return error;
 228                         break;
 229                     case MB_MINLINE:
 230                         for (src = source, count = cplen; count; count--)
 231                                 *dst++ = *src++;
 232                         break;
 233                     case MB_MSYSTEM:
 234                         bcopy(source, dst, cplen);
 235                         break;
 236                     case MB_MUSER:
 237                         error = copyin(source, dst, cplen);
 238                         if (error)
 239                                 return error;
 240                         break;
 241                     case MB_MZERO:
 242                         bzero(dst, cplen);
 243                         break;
 244                 }
 245                 size -= srclen;
 246                 source += srclen;
 247                 m->m_len += dstlen;
 248                 mleft -= dstlen;
 249                 mbp->mb_count += dstlen;
 250         }
 251         mbp->mb_cur = m;
 252         mbp->mb_mleft = mleft;
 253         return 0;
 254 }
 255
 256 int
 257 mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
 258 {
 259         mbp->mb_cur->m_next = m;
 260         while (m) {
 261                 mbp->mb_count += m->m_len;
 262                 if (m->m_next == NULL)
 263                         break;
 264                 m = m->m_next;
 265         }
 266         mbp->mb_mleft = M_TRAILINGSPACE(m);
 267         mbp->mb_cur = m;
 268         return 0;
 269 }
 270
 271 /*
 272  * copies a uio scatter/gather list to an mbuf chain.
 273  */
 274 int
 275 mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
 276 {
 277         long left;
 278         int mtype, error;
 279
 280         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
 281
 282         while (size > 0 && uiop->uio_resid) {
 283                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
 284                         return EFBIG;
 285                 left = uiop->uio_iov->iov_len;
 286                 if (left == 0) {
 287                         uiop->uio_iov++;
 288                         uiop->uio_iovcnt--;
 289                         continue;
 290                 }
 291                 if (left > size)
 292                         left = size;
 293                 error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
 294                 if (error)
 295                         return error;
 296                 uiop->uio_offset += left;
 297                 uiop->uio_resid -= left;
 298                 uiop->uio_iov->iov_base =
 299                     (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(M_WAITOK, 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         if (x != NULL)
 398                 *x = le16toh(v);
 399         return error;
 400 }
 401
 402 int
 403 md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
 404         u_int16_t v;
 405         int error = md_get_uint16(mdp, &v);
 406
 407         if (x != NULL)
 408                 *x = be16toh(v);
 409         return error;
 410 }
 411
 412 int
 413 md_get_uint32(struct mdchain *mdp, u_int32_t *x)
 414 {
 415         return md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE);
 416 }
 417
 418 int
 419 md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
 420 {
 421         u_int32_t v;
 422         int error;
 423
 424         error = md_get_uint32(mdp, &v);
 425         if (x != NULL)
 426                 *x = be32toh(v);
 427         return error;
 428 }
 429
 430 int
 431 md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
 432 {
 433         u_int32_t v;
 434         int error;
 435
 436         error = md_get_uint32(mdp, &v);
 437         if (x != NULL)
 438                 *x = le32toh(v);
 439         return error;
 440 }
 441
 442 int
 443 md_get_int64(struct mdchain *mdp, int64_t *x)
 444 {
 445         return md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE);
 446 }
 447
 448 int
 449 md_get_int64be(struct mdchain *mdp, int64_t *x)
 450 {
 451         int64_t v;
 452         int error;
 453
 454         error = md_get_int64(mdp, &v);
 455         if (x != NULL)
 456                 *x = be64toh(v);
 457         return error;
 458 }
 459
 460 int
 461 md_get_int64le(struct mdchain *mdp, int64_t *x)
 462 {
 463         int64_t v;
 464         int error;
 465
 466         error = md_get_int64(mdp, &v);
 467         if (x != NULL)
 468                 *x = le64toh(v);
 469         return error;
 470 }
 471
 472 int
 473 md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
 474 {
 475         struct mbuf *m = mdp->md_cur;
 476         int error;
 477         u_int count;
 478         u_char *s;
 479
 480         while (size > 0) {
 481                 if (m == NULL) {
 482                         MBERROR("incomplete copy\n");
 483                         return EBADRPC;
 484                 }
 485                 s = mdp->md_pos;
 486                 count = mtod(m, u_char*) + m->m_len - s;
 487                 if (count == 0) {
 488                         mdp->md_cur = m = m->m_next;
 489                         if (m)
 490                                 s = mdp->md_pos = mtod(m, caddr_t);
 491                         continue;
 492                 }
 493                 if (count > size)
 494                         count = size;
 495                 size -= count;
 496                 mdp->md_pos += count;
 497                 if (target == NULL)
 498                         continue;
 499                 switch (type) {
 500                     case MB_MUSER:
 501                         error = copyout(s, target, count);
 502                         if (error)
 503                                 return error;
 504                         break;
 505                     case MB_MSYSTEM:
 506                         bcopy(s, target, count);
 507                         break;
 508                     case MB_MINLINE:
 509                         while (count--)
 510                                 *target++ = *s++;
 511                         continue;
 512                 }
 513                 target += count;
 514         }
 515         return 0;
 516 }
 517
 518 int
 519 md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
 520 {
 521         struct mbuf *m = mdp->md_cur, *rm;
 522
 523         rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_WAITOK);
 524         if (rm == NULL)
 525                 return EBADRPC;
 526         md_get_mem(mdp, NULL, size, MB_MZERO);
 527         *ret = rm;
 528         return 0;
 529 }
 530
 531 int
 532 md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
 533 {
 534         char *uiocp;
 535         long left;
 536         int mtype, error;
 537
 538         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
 539         while (size > 0 && uiop->uio_resid) {
 540                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
 541                         return EFBIG;
 542                 left = uiop->uio_iov->iov_len;
 543                 if (left == 0) {
 544                         uiop->uio_iov++;
 545                         uiop->uio_iovcnt--;
 546                         continue;
 547                 }
 548                 uiocp = uiop->uio_iov->iov_base;
 549                 if (left > size)
 550                         left = size;
 551                 error = md_get_mem(mdp, uiocp, left, mtype);
 552                 if (error)
 553                         return error;
 554                 uiop->uio_offset += left;
 555                 uiop->uio_resid -= left;
 556                 uiop->uio_iov->iov_base =
 557                     (char *)uiop->uio_iov->iov_base + left;
 558                 uiop->uio_iov->iov_len -= left;
 559                 size -= left;
 560         }
 561         return 0;
 562 }