subr_mchain.c

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    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/endian.h>
   36 #include <sys/errno.h>
   37 #include <sys/mbuf.h>
   38 #include <sys/module.h>
   39 #include <sys/uio.h>
   40 
   41 #include <sys/mchain.h>
   42 
   43 MODULE_VERSION(libmchain, 1);
   44 
   45 #define MBERROR(format, ...) printf("%s(%d): "format, __func__ , \
   46                                     __LINE__ , ## __VA_ARGS__)
   47 
   48 #define MBPANIC(format, ...) printf("%s(%d): "format, __func__ , \
   49                                     __LINE__ , ## __VA_ARGS__)
   50 
   51 /*
   52  * Various helper functions
   53  */
   54 int
   55 mb_init(struct mbchain *mbp)
   56 {
   57         struct mbuf *m;
   58 
   59         m = m_gethdr(M_TRYWAIT, MT_DATA);
   60         if (m == NULL) 
   61                 return ENOBUFS;
   62         m->m_len = 0;
   63         mb_initm(mbp, m);
   64         return 0;
   65 }
   66 
   67 void
   68 mb_initm(struct mbchain *mbp, struct mbuf *m)
   69 {
   70         bzero(mbp, sizeof(*mbp));
   71         mbp->mb_top = mbp->mb_cur = m;
   72         mbp->mb_mleft = M_TRAILINGSPACE(m);
   73 }
   74 
   75 void
   76 mb_done(struct mbchain *mbp)
   77 {
   78         if (mbp->mb_top) {
   79                 m_freem(mbp->mb_top);
   80                 mbp->mb_top = NULL;
   81         }
   82 }
   83 
   84 struct mbuf *
   85 mb_detach(struct mbchain *mbp)
   86 {
   87         struct mbuf *m;
   88 
   89         m = mbp->mb_top;
   90         mbp->mb_top = NULL;
   91         return m;
   92 }
   93 
   94 int
   95 mb_fixhdr(struct mbchain *mbp)
   96 {
   97         return mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top);
   98 }
   99 
  100 /*
  101  * Check if object of size 'size' fit to the current position and
  102  * allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
  103  * Return pointer to the object placeholder or NULL if any error occured.
  104  * Note: size should be <= MLEN 
  105  */
  106 caddr_t
  107 mb_reserve(struct mbchain *mbp, int size)
  108 {
  109         struct mbuf *m, *mn;
  110         caddr_t bpos;
  111 
  112         if (size > MLEN)
  113                 panic("mb_reserve: size = %d\n", size);
  114         m = mbp->mb_cur;
  115         if (mbp->mb_mleft < size) {
  116                 mn = m_get(M_TRYWAIT, MT_DATA);
  117                 if (mn == NULL)
  118                         return NULL;
  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_uint8(struct mbchain *mbp, u_int8_t x)
  133 {
  134         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
  135 }
  136 
  137 int
  138 mb_put_uint16be(struct mbchain *mbp, u_int16_t x)
  139 {
  140         x = htobe16(x);
  141         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
  142 }
  143 
  144 int
  145 mb_put_uint16le(struct mbchain *mbp, u_int16_t x)
  146 {
  147         x = htole16(x);
  148         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
  149 }
  150 
  151 int
  152 mb_put_uint32be(struct mbchain *mbp, u_int32_t x)
  153 {
  154         x = htobe32(x);
  155         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
  156 }
  157 
  158 int
  159 mb_put_uint32le(struct mbchain *mbp, u_int32_t x)
  160 {
  161         x = htole32(x);
  162         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
  163 }
  164 
  165 int
  166 mb_put_int64be(struct mbchain *mbp, int64_t x)
  167 {
  168         x = htobe64(x);
  169         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
  170 }
  171 
  172 int
  173 mb_put_int64le(struct mbchain *mbp, int64_t x)
  174 {
  175         x = htole64(x);
  176         return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
  177 }
  178 
  179 int
  180 mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
  181 {
  182         struct mbuf *m;
  183         caddr_t dst;
  184         c_caddr_t src;
  185         int cplen, error, mleft, count;
  186         size_t srclen, dstlen;
  187 
  188         m = mbp->mb_cur;
  189         mleft = mbp->mb_mleft;
  190 
  191         while (size > 0) {
  192                 if (mleft == 0) {
  193                         if (m->m_next == NULL) {
  194                                 m = m_getm(m, size, M_TRYWAIT, MT_DATA);
  195                                 if (m == NULL)
  196                                         return ENOBUFS;
  197                         } else
  198                                 m = m->m_next;
  199                         mleft = M_TRAILINGSPACE(m);
  200                         continue;
  201                 }
  202                 cplen = mleft > size ? size : mleft;
  203                 srclen = dstlen = cplen;
  204                 dst = mtod(m, caddr_t) + m->m_len;
  205                 switch (type) {
  206                     case MB_MCUSTOM:
  207                         srclen = size;
  208                         dstlen = mleft;
  209                         error = mbp->mb_copy(mbp, source, dst, &srclen, &dstlen);
  210                         if (error)
  211                                 return error;
  212                         break;
  213                     case MB_MINLINE:
  214                         for (src = source, count = cplen; count; count--)
  215                                 *dst++ = *src++;
  216                         break;
  217                     case MB_MSYSTEM:
  218                         bcopy(source, dst, cplen);
  219                         break;
  220                     case MB_MUSER:
  221                         error = copyin(source, dst, cplen);
  222                         if (error)
  223                                 return error;
  224                         break;
  225                     case MB_MZERO:
  226                         bzero(dst, cplen);
  227                         break;
  228                 }
  229                 size -= srclen;
  230                 source += srclen;
  231                 m->m_len += dstlen;
  232                 mleft -= dstlen;
  233                 mbp->mb_count += dstlen;
  234         }
  235         mbp->mb_cur = m;
  236         mbp->mb_mleft = mleft;
  237         return 0;
  238 }
  239 
  240 int
  241 mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
  242 {
  243         mbp->mb_cur->m_next = m;
  244         while (m) {
  245                 mbp->mb_count += m->m_len;
  246                 if (m->m_next == NULL)
  247                         break;
  248                 m = m->m_next;
  249         }
  250         mbp->mb_mleft = M_TRAILINGSPACE(m);
  251         mbp->mb_cur = m;
  252         return 0;
  253 }
  254 
  255 /*
  256  * copies a uio scatter/gather list to an mbuf chain.
  257  */
  258 int
  259 mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
  260 {
  261         long left;
  262         int mtype, error;
  263 
  264         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
  265 
  266         while (size > 0 && uiop->uio_resid) {
  267                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
  268                         return EFBIG;
  269                 left = uiop->uio_iov->iov_len;
  270                 if (left == 0) {
  271                         uiop->uio_iov++;
  272                         uiop->uio_iovcnt--;
  273                         continue;
  274                 }
  275                 if (left > size)
  276                         left = size;
  277                 error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
  278                 if (error)
  279                         return error;
  280                 uiop->uio_offset += left;
  281                 uiop->uio_resid -= left;
  282                 uiop->uio_iov->iov_base =
  283                     (char *)uiop->uio_iov->iov_base + left;
  284                 uiop->uio_iov->iov_len -= left;
  285                 size -= left;
  286         }
  287         return 0;
  288 }
  289 
  290 /*
  291  * Routines for fetching data from an mbuf chain
  292  */
  293 int
  294 md_init(struct mdchain *mdp)
  295 {
  296         struct mbuf *m;
  297 
  298         m = m_gethdr(M_TRYWAIT, MT_DATA);
  299         if (m == NULL) 
  300                 return ENOBUFS;
  301         m->m_len = 0;
  302         md_initm(mdp, m);
  303         return 0;
  304 }
  305 
  306 void
  307 md_initm(struct mdchain *mdp, struct mbuf *m)
  308 {
  309         bzero(mdp, sizeof(*mdp));
  310         mdp->md_top = mdp->md_cur = m;
  311         mdp->md_pos = mtod(m, u_char*);
  312 }
  313 
  314 void
  315 md_done(struct mdchain *mdp)
  316 {
  317         if (mdp->md_top) {
  318                 m_freem(mdp->md_top);
  319                 mdp->md_top = NULL;
  320         }
  321 }
  322 
  323 /*
  324  * Append a separate mbuf chain. It is caller responsibility to prevent
  325  * multiple calls to fetch/record routines.
  326  */
  327 void
  328 md_append_record(struct mdchain *mdp, struct mbuf *top)
  329 {
  330         struct mbuf *m;
  331 
  332         if (mdp->md_top == NULL) {
  333                 md_initm(mdp, top);
  334                 return;
  335         }
  336         m = mdp->md_top;
  337         while (m->m_nextpkt)
  338                 m = m->m_nextpkt;
  339         m->m_nextpkt = top;
  340         top->m_nextpkt = NULL;
  341         return;
  342 }
  343 
  344 /*
  345  * Put next record in place of existing
  346  */
  347 int
  348 md_next_record(struct mdchain *mdp)
  349 {
  350         struct mbuf *m;
  351 
  352         if (mdp->md_top == NULL)
  353                 return ENOENT;
  354         m = mdp->md_top->m_nextpkt;
  355         md_done(mdp);
  356         if (m == NULL)
  357                 return ENOENT;
  358         md_initm(mdp, m);
  359         return 0;
  360 }
  361 
  362 int
  363 md_get_uint8(struct mdchain *mdp, u_int8_t *x)
  364 {
  365         return md_get_mem(mdp, x, 1, MB_MINLINE);
  366 }
  367 
  368 int
  369 md_get_uint16(struct mdchain *mdp, u_int16_t *x)
  370 {
  371         return md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE);
  372 }
  373 
  374 int
  375 md_get_uint16le(struct mdchain *mdp, u_int16_t *x)
  376 {
  377         u_int16_t v;
  378         int error = md_get_uint16(mdp, &v);
  379 
  380         if (x != NULL)
  381                 *x = le16toh(v);
  382         return error;
  383 }
  384 
  385 int
  386 md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
  387         u_int16_t v;
  388         int error = md_get_uint16(mdp, &v);
  389 
  390         if (x != NULL)
  391                 *x = be16toh(v);
  392         return error;
  393 }
  394 
  395 int
  396 md_get_uint32(struct mdchain *mdp, u_int32_t *x)
  397 {
  398         return md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE);
  399 }
  400 
  401 int
  402 md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
  403 {
  404         u_int32_t v;
  405         int error;
  406 
  407         error = md_get_uint32(mdp, &v);
  408         if (x != NULL)
  409                 *x = be32toh(v);
  410         return error;
  411 }
  412 
  413 int
  414 md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
  415 {
  416         u_int32_t v;
  417         int error;
  418 
  419         error = md_get_uint32(mdp, &v);
  420         if (x != NULL)
  421                 *x = le32toh(v);
  422         return error;
  423 }
  424 
  425 int
  426 md_get_int64(struct mdchain *mdp, int64_t *x)
  427 {
  428         return md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE);
  429 }
  430 
  431 int
  432 md_get_int64be(struct mdchain *mdp, int64_t *x)
  433 {
  434         int64_t v;
  435         int error;
  436 
  437         error = md_get_int64(mdp, &v);
  438         if (x != NULL)
  439                 *x = be64toh(v);
  440         return error;
  441 }
  442 
  443 int
  444 md_get_int64le(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 = le64toh(v);
  452         return error;
  453 }
  454 
  455 int
  456 md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
  457 {
  458         struct mbuf *m = mdp->md_cur;
  459         int error;
  460         u_int count;
  461         u_char *s;
  462         
  463         while (size > 0) {
  464                 if (m == NULL) {
  465                         MBERROR("incomplete copy\n");
  466                         return EBADRPC;
  467                 }
  468                 s = mdp->md_pos;
  469                 count = mtod(m, u_char*) + m->m_len - s;
  470                 if (count == 0) {
  471                         mdp->md_cur = m = m->m_next;
  472                         if (m)
  473                                 s = mdp->md_pos = mtod(m, caddr_t);
  474                         continue;
  475                 }
  476                 if (count > size)
  477                         count = size;
  478                 size -= count;
  479                 mdp->md_pos += count;
  480                 if (target == NULL)
  481                         continue;
  482                 switch (type) {
  483                     case MB_MUSER:
  484                         error = copyout(s, target, count);
  485                         if (error)
  486                                 return error;
  487                         break;
  488                     case MB_MSYSTEM:
  489                         bcopy(s, target, count);
  490                         break;
  491                     case MB_MINLINE:
  492                         while (count--)
  493                                 *target++ = *s++;
  494                         continue;
  495                 }
  496                 target += count;
  497         }
  498         return 0;
  499 }
  500 
  501 int
  502 md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
  503 {
  504         struct mbuf *m = mdp->md_cur, *rm;
  505 
  506         rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_TRYWAIT);
  507         if (rm == NULL)
  508                 return EBADRPC;
  509         md_get_mem(mdp, NULL, size, MB_MZERO);
  510         *ret = rm;
  511         return 0;
  512 }
  513 
  514 int
  515 md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
  516 {
  517         char *uiocp;
  518         long left;
  519         int mtype, error;
  520 
  521         mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
  522         while (size > 0 && uiop->uio_resid) {
  523                 if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
  524                         return EFBIG;
  525                 left = uiop->uio_iov->iov_len;
  526                 if (left == 0) {
  527                         uiop->uio_iov++;
  528                         uiop->uio_iovcnt--;
  529                         continue;
  530                 }
  531                 uiocp = uiop->uio_iov->iov_base;
  532                 if (left > size)
  533                         left = size;
  534                 error = md_get_mem(mdp, uiocp, left, mtype);
  535                 if (error)
  536                         return error;
  537                 uiop->uio_offset += left;
  538                 uiop->uio_resid -= left;
  539                 uiop->uio_iov->iov_base =
  540                     (char *)uiop->uio_iov->iov_base + left;
  541                 uiop->uio_iov->iov_len -= left;
  542                 size -= left;
  543         }
  544         return 0;
  545 }
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FreeBSD/Linux Kernel Cross Reference sys/kern/subr_mchain.c

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