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 cplen, error, mleft, count;
 206
 207         m = mbp->mb_cur;
 208         mleft = mbp->mb_mleft;
 209
 210         while (size > 0) {
 211                 if (mleft == 0) {
 212                         if (m->m_next == NULL) {
 213                                 m->m_next = m_getc(size, MB_WAIT, MT_DATA);
 214                                 if (m == NULL)
 215                                         return ENOBUFS;
 216                         }
 217                         m = m->m_next;
 218                         mleft = M_TRAILINGSPACE(m);
 219                         continue;
 220                 }
 221                 cplen = mleft > size ? size : mleft;
 222                 dst = mtod(m, caddr_t) + m->m_len;
 223                 switch (type) {
 224                     case MB_MCUSTOM:
 225                         error = mbp->mb_copy(mbp, source, dst, cplen);
 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 -= cplen;
 246                 source += cplen;
 247                 m->m_len += cplen;
 248                 mleft -= cplen;
 249                 mbp->mb_count += cplen;
 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 += left;
 299                 uiop->uio_iov->iov_len -= left;
 300                 size -= left;
 301         }
 302         return 0;
 303 }
 304
 305 /*
 306  * Routines for fetching data from an mbuf chain
 307  */
 308 int
 309 md_init(struct mdchain *mdp)
 310 {
 311         struct mbuf *m;
 312
 313         m = m_gethdr(MB_WAIT, MT_DATA);
 314         if (m == NULL)
 315                 return ENOBUFS;
 316         m->m_pkthdr.rcvif = NULL;
 317         m->m_len = 0;
 318         md_initm(mdp, m);
 319         return 0;
 320 }
 321
 322 void
 323 md_initm(struct mdchain *mdp, struct mbuf *m)
 324 {
 325         bzero(mdp, sizeof(*mdp));
 326         mdp->md_top = mdp->md_cur = m;
 327         mdp->md_pos = mtod(m, u_char*);
 328 }
 329
 330 void
 331 md_done(struct mdchain *mdp)
 332 {
 333         if (mdp->md_top) {
 334                 m_freem(mdp->md_top);
 335                 mdp->md_top = NULL;
 336         }
 337 }
 338
 339 /*
 340  * Append a separate mbuf chain. It is caller responsibility to prevent
 341  * multiple calls to fetch/record routines.
 342  */
 343 void
 344 md_append_record(struct mdchain *mdp, struct mbuf *top)
 345 {
 346         struct mbuf *m;
 347
 348         if (mdp->md_top == NULL) {
 349                 md_initm(mdp, top);
 350                 return;
 351         }
 352         m = mdp->md_top;
 353         while (m->m_nextpkt)
 354                 m = m->m_nextpkt;
 355         m->m_nextpkt = top;
 356         top->m_nextpkt = NULL;
 357         return;
 358 }
 359
 360 /*
 361  * Put next record in place of existing
 362  */
 363 int
 364 md_next_record(struct mdchain *mdp)
 365 {
 366         struct mbuf *m;
 367
 368         if (mdp->md_top == NULL)
 369                 return ENOENT;
 370         m = mdp->md_top->m_nextpkt;
 371         md_done(mdp);
 372         if (m == NULL)
 373                 return ENOENT;
 374         md_initm(mdp, m);
 375         return 0;
 376 }
 377
 378 int
 379 md_get_uint8(struct mdchain *mdp, u_int8_t *x)
 380 {
 381         return md_get_mem(mdp, x, 1, MB_MINLINE);
 382 }
 383
 384 int
 385 md_get_uint16(struct mdchain *mdp, u_int16_t *x)
 386 {
 387         return md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE);
 388 }
 389
 390 int
 391 md_get_uint16le(struct mdchain *mdp, u_int16_t *x)
 392 {
 393         u_int16_t v;
 394         int error = md_get_uint16(mdp, &v);
 395
 396         *x = letohs(v);
 397         return error;
 398 }
 399
 400 int
 401 md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
 402         u_int16_t v;
 403         int error = md_get_uint16(mdp, &v);
 404
 405         *x = betohs(v);
 406         return error;
 407 }
 408
 409 int
 410 md_get_uint32(struct mdchain *mdp, u_int32_t *x)
 411 {
 412         return md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE);
 413 }
 414
 415 int
 416 md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
 417 {
 418         u_int32_t v;
 419         int error;
 420
 421         error = md_get_uint32(mdp, &v);
 422         *x = betohl(v);
 423         return error;
 424 }
 425
 426 int
 427 md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
 428 {
 429         u_int32_t v;
 430         int error;
 431
 432         error = md_get_uint32(mdp, &v);
 433         *x = letohl(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         *x = betohq(v);
 451         return error;
 452 }
 453
 454 int
 455 md_get_int64le(struct mdchain *mdp, int64_t *x)
 456 {
 457         int64_t v;
 458         int error;
 459
 460         error = md_get_int64(mdp, &v);
 461         *x = letohq(v);
 462         return error;
 463 }
 464
 465 int
 466 md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
 467 {
 468         struct mbuf *m = mdp->md_cur;
 469         int error;
 470         u_int count;
 471         u_char *s;
 472
 473         while (size > 0) {
 474                 if (m == NULL) {
 475                         MBERROR("incomplete copy\n");
 476                         return EBADRPC;
 477                 }
 478                 s = mdp->md_pos;
 479                 count = mtod(m, u_char*) + m->m_len - s;
 480                 if (count == 0) {
 481                         mdp->md_cur = m = m->m_next;
 482                         if (m)
 483                                 s = mdp->md_pos = mtod(m, caddr_t);
 484                         continue;
 485                 }
 486                 if (count > size)
 487                         count = size;
 488                 size -= count;
 489                 mdp->md_pos += count;
 490                 if (target == NULL)
 491                         continue;
 492                 switch (type) {
 493                     case MB_MUSER:
 494                         error = copyout(s, target, count);
 495                         if (error)
 496                                 return error;
 497                         break;
 498                     case MB_MSYSTEM:
 499                         bcopy(s, target, count);
 500                         break;
 501                     case MB_MINLINE:
 502                         while (count--)
 503                                 *target++ = *s++;
 504                         continue;
 505                 }
 506                 target += count;
 507         }
 508         return 0;
 509 }
 510
 511 int
 512 md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
 513 {
 514         struct mbuf *m = mdp->md_cur, *rm;
 515
 516         rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, MB_WAIT);
 517         if (rm == NULL)
 518                 return EBADRPC;
 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 += left;
 550                 uiop->uio_iov->iov_len -= left;
 551                 size -= left;
 552         }
 553         return 0;
 554 }