subr_mchain.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 2000, 2001 Boris Popov
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the author nor the names of any co-contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD$");
   34 
   35 #include <sys/param.h>
   36 #include <sys/systm.h>
   37 #include <sys/sysctl.h>
   38 #include <sys/endian.h>
   39 #include <sys/errno.h>
   40 #include <sys/malloc.h>
   41 #include <sys/mbuf.h>
   42 #include <sys/module.h>
   43 #include <sys/uio.h>
   44 
   45 #include <sys/mchain.h>
   46 
   47 FEATURE(libmchain, "mchain library");
   48 
   49 MODULE_VERSION(libmchain, 1);
   50 
   51 #define MBERROR(format, ...) printf("%s(%d): "format, __func__ , \
   52                                     __LINE__ , ## __VA_ARGS__)
   53 
   54 #define MBPANIC(format, ...) printf("%s(%d): "format, __func__ , \
   55                                     __LINE__ , ## __VA_ARGS__)
   56 
   57 /*
   58  * Various helper functions
   59  */
   60 int
   61 mb_init(struct mbchain *mbp)
   62 {
   63         struct mbuf *m;
   64 
   65         m = m_gethdr(M_WAITOK, MT_DATA);
   66         m->m_len = 0;
   67         mb_initm(mbp, m);
   68         return (0);
   69 }
   70 
   71 void
   72 mb_initm(struct mbchain *mbp, struct mbuf *m)
   73 {
   74         bzero(mbp, sizeof(*mbp));
   75         mbp->mb_top = mbp->mb_cur = m;
   76         mbp->mb_mleft = M_TRAILINGSPACE(m);
   77 }
   78 
   79 void
   80 mb_done(struct mbchain *mbp)
   81 {
   82         if (mbp->mb_top) {
   83                 m_freem(mbp->mb_top);
   84                 mbp->mb_top = NULL;
   85         }
   86 }
   87 
   88 struct mbuf *
   89 mb_detach(struct mbchain *mbp)
   90 {
   91         struct mbuf *m;
   92 
   93         m = mbp->mb_top;
   94         mbp->mb_top = NULL;
   95         return (m);
   96 }
   97 
   98 int
   99 mb_fixhdr(struct mbchain *mbp)
  100 {
  101         return (mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top));
  102 }
  103 
  104 /*
  105  * Check if object of size 'size' fit to the current position and
  106  * allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
  107  * Return pointer to the object placeholder or NULL if any error occurred.
  108  * Note: size should be <= MLEN 
  109  */
  110 caddr_t
  111 mb_reserve(struct mbchain *mbp, int size)
  112 {
  113         struct mbuf *m, *mn;
  114         caddr_t bpos;
  115 
  116         if (size > MLEN)
  117                 panic("mb_reserve: size = %d\n", size);
  118         m = mbp->mb_cur;
  119         if (mbp->mb_mleft < size) {
  120                 mn = m_get(M_WAITOK, MT_DATA);
  121                 mbp->mb_cur = m->m_next = mn;
  122                 m = mn;
  123                 m->m_len = 0;
  124                 mbp->mb_mleft = M_TRAILINGSPACE(m);
  125         }
  126         mbp->mb_mleft -= size;
  127         mbp->mb_count += size;
  128         bpos = mtod(m, caddr_t) + m->m_len;
  129         m->m_len += size;
  130         return (bpos);
  131 }
  132 
  133 int
  134 mb_put_padbyte(struct mbchain *mbp)
  135 {
  136         caddr_t dst;
  137         uint8_t x = 0;
  138 
  139         dst = mtod(mbp->mb_cur, caddr_t) + mbp->mb_cur->m_len;
  140 
  141         /* Only add padding if address is odd */
  142         if ((unsigned long)dst & 1)
  143                 return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  144         else
  145                 return (0);
  146 }
  147 
  148 int
  149 mb_put_uint8(struct mbchain *mbp, uint8_t x)
  150 {
  151         return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  152 }
  153 
  154 int
  155 mb_put_uint16be(struct mbchain *mbp, uint16_t x)
  156 {
  157         x = htobe16(x);
  158         return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  159 }
  160 
  161 int
  162 mb_put_uint16le(struct mbchain *mbp, uint16_t x)
  163 {
  164         x = htole16(x);
  165         return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  166 }
  167 
  168 int
  169 mb_put_uint32be(struct mbchain *mbp, uint32_t x)
  170 {
  171         x = htobe32(x);
  172         return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  173 }
  174 
  175 int
  176 mb_put_uint32le(struct mbchain *mbp, uint32_t x)
  177 {
  178         x = htole32(x);
  179         return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  180 }
  181 
  182 int
  183 mb_put_int64be(struct mbchain *mbp, int64_t x)
  184 {
  185         x = htobe64(x);
  186         return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  187 }
  188 
  189 int
  190 mb_put_int64le(struct mbchain *mbp, int64_t x)
  191 {
  192         x = htole64(x);
  193         return (mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM));
  194 }
  195 
  196 int
  197 mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
  198 {
  199         struct mbuf *m;
  200         caddr_t dst;
  201         c_caddr_t src;
  202         int cplen, error, mleft, count;
  203         size_t srclen, dstlen;
  204 
  205         m = mbp->mb_cur;
  206         mleft = mbp->mb_mleft;
  207 
  208         while (size > 0) {
  209                 if (mleft == 0) {
  210                         if (m->m_next == NULL)
  211                                 m = m_getm(m, size, M_WAITOK, MT_DATA);
  212                         else
  213                                 m = m->m_next;
  214                         mleft = M_TRAILINGSPACE(m);
  215                         continue;
  216                 }
  217                 cplen = mleft > size ? size : mleft;
  218                 srclen = dstlen = cplen;
  219                 dst = mtod(m, caddr_t) + m->m_len;
  220                 switch (type) {
  221                     case MB_MCUSTOM:
  222                         srclen = size;
  223                         dstlen = mleft;
  224                         error = mbp->mb_copy(mbp, source, dst, &srclen, &dstlen);
  225                         if (error)
  226                                 return (error);
  227                         break;
  228                     case MB_MINLINE:
  229                         for (src = source, count = cplen; count; count--)
  230                                 *dst++ = *src++;
  231                         break;
  232                     case MB_MSYSTEM:
  233                         bcopy(source, dst, cplen);
  234                         break;
  235                     case MB_MUSER:
  236                         error = copyin(source, dst, cplen);
  237                         if (error)
  238                                 return (error);
  239                         break;
  240                     case MB_MZERO:
  241                         bzero(dst, cplen);
  242                         break;
  243                 }
  244                 size -= srclen;
  245                 source += srclen;
  246                 m->m_len += dstlen;
  247                 mleft -= dstlen;
  248                 mbp->mb_count += dstlen;
  249         }
  250         mbp->mb_cur = m;
  251         mbp->mb_mleft = mleft;
  252         return (0);
  253 }
  254 
  255 int
  256 mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
  257 {
  258         mbp->mb_cur->m_next = m;
  259         while (m) {
  260                 mbp->mb_count += m->m_len;
  261                 if (m->m_next == NULL)
  262                         break;
  263                 m = m->m_next;
  264         }
  265         mbp->mb_mleft = M_TRAILINGSPACE(m);
  266         mbp->mb_cur = m;
  267         return (0);
  268 }
  269 
  270 /*
  271  * copies a uio scatter/gather list to an mbuf chain.
  272  */
  273 int
  274 mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
  275 {
  276         long left;
  277         int mtype, error;
  278 
  279         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
  280 
  281         while (size > 0 && uiop->uio_resid) {
  282                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
  283                         return (EFBIG);
  284                 left = uiop->uio_iov->iov_len;
  285                 if (left == 0) {
  286                         uiop->uio_iov++;
  287                         uiop->uio_iovcnt--;
  288                         continue;
  289                 }
  290                 if (left > size)
  291                         left = size;
  292                 error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
  293                 if (error)
  294                         return (error);
  295                 uiop->uio_offset += left;
  296                 uiop->uio_resid -= left;
  297                 uiop->uio_iov->iov_base =
  298                     (char *)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(M_WAITOK, MT_DATA);
  314         m->m_len = 0;
  315         md_initm(mdp, m);
  316         return (0);
  317 }
  318 
  319 void
  320 md_initm(struct mdchain *mdp, struct mbuf *m)
  321 {
  322         bzero(mdp, sizeof(*mdp));
  323         mdp->md_top = mdp->md_cur = m;
  324         mdp->md_pos = mtod(m, u_char*);
  325 }
  326 
  327 void
  328 md_done(struct mdchain *mdp)
  329 {
  330         if (mdp->md_top) {
  331                 m_freem(mdp->md_top);
  332                 mdp->md_top = NULL;
  333         }
  334 }
  335 
  336 /*
  337  * Append a separate mbuf chain. It is caller responsibility to prevent
  338  * multiple calls to fetch/record routines.
  339  */
  340 void
  341 md_append_record(struct mdchain *mdp, struct mbuf *top)
  342 {
  343         struct mbuf *m;
  344 
  345         if (mdp->md_top == NULL) {
  346                 md_initm(mdp, top);
  347                 return;
  348         }
  349         m = mdp->md_top;
  350         while (m->m_nextpkt)
  351                 m = m->m_nextpkt;
  352         m->m_nextpkt = top;
  353         top->m_nextpkt = NULL;
  354         return;
  355 }
  356 
  357 /*
  358  * Put next record in place of existing
  359  */
  360 int
  361 md_next_record(struct mdchain *mdp)
  362 {
  363         struct mbuf *m;
  364 
  365         if (mdp->md_top == NULL)
  366                 return (ENOENT);
  367         m = mdp->md_top->m_nextpkt;
  368         md_done(mdp);
  369         if (m == NULL)
  370                 return (ENOENT);
  371         md_initm(mdp, m);
  372         return (0);
  373 }
  374 
  375 int
  376 md_get_uint8(struct mdchain *mdp, uint8_t *x)
  377 {
  378         return (md_get_mem(mdp, x, 1, MB_MINLINE));
  379 }
  380 
  381 int
  382 md_get_uint16(struct mdchain *mdp, uint16_t *x)
  383 {
  384         return (md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE));
  385 }
  386 
  387 int
  388 md_get_uint16le(struct mdchain *mdp, uint16_t *x)
  389 {
  390         uint16_t v;
  391         int error = md_get_uint16(mdp, &v);
  392 
  393         if (x != NULL)
  394                 *x = le16toh(v);
  395         return (error);
  396 }
  397 
  398 int
  399 md_get_uint16be(struct mdchain *mdp, uint16_t *x)
  400 {
  401         uint16_t v;
  402         int error = md_get_uint16(mdp, &v);
  403 
  404         if (x != NULL)
  405                 *x = be16toh(v);
  406         return (error);
  407 }
  408 
  409 int
  410 md_get_uint32(struct mdchain *mdp, uint32_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, uint32_t *x)
  417 {
  418         uint32_t v;
  419         int error;
  420 
  421         error = md_get_uint32(mdp, &v);
  422         if (x != NULL)
  423                 *x = be32toh(v);
  424         return (error);
  425 }
  426 
  427 int
  428 md_get_uint32le(struct mdchain *mdp, uint32_t *x)
  429 {
  430         uint32_t v;
  431         int error;
  432 
  433         error = md_get_uint32(mdp, &v);
  434         if (x != NULL)
  435                 *x = le32toh(v);
  436         return (error);
  437 }
  438 
  439 int
  440 md_get_int64(struct mdchain *mdp, int64_t *x)
  441 {
  442         return (md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE));
  443 }
  444 
  445 int
  446 md_get_int64be(struct mdchain *mdp, int64_t *x)
  447 {
  448         int64_t v;
  449         int error;
  450 
  451         error = md_get_int64(mdp, &v);
  452         if (x != NULL)
  453                 *x = be64toh(v);
  454         return (error);
  455 }
  456 
  457 int
  458 md_get_int64le(struct mdchain *mdp, int64_t *x)
  459 {
  460         int64_t v;
  461         int error;
  462 
  463         error = md_get_int64(mdp, &v);
  464         if (x != NULL)
  465                 *x = le64toh(v);
  466         return (error);
  467 }
  468 
  469 int
  470 md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
  471 {
  472         struct mbuf *m = mdp->md_cur;
  473         int error;
  474         u_int count;
  475         u_char *s;
  476 
  477         while (size > 0) {
  478                 if (m == NULL) {
  479                         MBERROR("incomplete copy\n");
  480                         return (EBADRPC);
  481                 }
  482                 s = mdp->md_pos;
  483                 count = mtod(m, u_char*) + m->m_len - s;
  484                 if (count == 0) {
  485                         mdp->md_cur = m = m->m_next;
  486                         if (m)
  487                                 s = mdp->md_pos = mtod(m, caddr_t);
  488                         continue;
  489                 }
  490                 if (count > size)
  491                         count = size;
  492                 size -= count;
  493                 mdp->md_pos += count;
  494                 if (target == NULL)
  495                         continue;
  496                 switch (type) {
  497                     case MB_MUSER:
  498                         error = copyout(s, target, count);
  499                         if (error)
  500                                 return error;
  501                         break;
  502                     case MB_MSYSTEM:
  503                         bcopy(s, target, count);
  504                         break;
  505                     case MB_MINLINE:
  506                         while (count--)
  507                                 *target++ = *s++;
  508                         continue;
  509                 }
  510                 target += count;
  511         }
  512         return (0);
  513 }
  514 
  515 int
  516 md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
  517 {
  518         struct mbuf *m = mdp->md_cur, *rm;
  519 
  520         rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_WAITOK);
  521         md_get_mem(mdp, NULL, size, MB_MZERO);
  522         *ret = rm;
  523         return (0);
  524 }
  525 
  526 int
  527 md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
  528 {
  529         char *uiocp;
  530         long left;
  531         int mtype, error;
  532 
  533         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
  534         while (size > 0 && uiop->uio_resid) {
  535                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
  536                         return (EFBIG);
  537                 left = uiop->uio_iov->iov_len;
  538                 if (left == 0) {
  539                         uiop->uio_iov++;
  540                         uiop->uio_iovcnt--;
  541                         continue;
  542                 }
  543                 uiocp = uiop->uio_iov->iov_base;
  544                 if (left > size)
  545                         left = size;
  546                 error = md_get_mem(mdp, uiocp, left, mtype);
  547                 if (error)
  548                         return (error);
  549                 uiop->uio_offset += left;
  550                 uiop->uio_resid -= left;
  551                 uiop->uio_iov->iov_base =
  552                     (char *)uiop->uio_iov->iov_base + left;
  553                 uiop->uio_iov->iov_len -= left;
  554                 size -= left;
  555         }
  556         return (0);
  557 }
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FreeBSD/Linux Kernel Cross Reference sys/kern/subr_mchain.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_mchain.c
