lib/roken/net_read.c

   1 /*
   2  * Copyright (c) 1995, 1996, 1997, 1998 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <config.h>
  35
  36 #include <sys/types.h>
  37 #include <unistd.h>
  38 #include <errno.h>
  39
  40 #include "roken.h"
  41
  42 /*
  43  * Like read but never return partial data.
  44  */
  45
  46 ssize_t ROKEN_LIB_FUNCTION
  47 net_read (int fd, void *buf, size_t nbytes)
  48 {
  49     char *cbuf = (char *)buf;
  50     ssize_t count;
  51     size_t rem = nbytes;
  52
  53     while (rem > 0) {
  54 #ifdef WIN32
  55         count = recv (fd, cbuf, rem, 0);
  56 #else
  57         count = read (fd, cbuf, rem);
  58 #endif
  59         if (count < 0) {
  60             if (errno == EINTR)
  61                 continue;
  62             else
  63                 return count;
  64         } else if (count == 0) {
  65             return count;
  66         }
  67         cbuf += count;
  68         rem -= count;
  69     }
  70     return nbytes;
  71 }