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 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 RCSID("$Id$");
  37 #endif
  38
  39 #include <sys/types.h>
  40 #include <unistd.h>
  41 #include <errno.h>
  42
  43 #include "roken.h"
  44
  45 /*
  46  * Like read but never return partial data.
  47  */
  48
  49 ssize_t ROKEN_LIB_FUNCTION
  50 net_read (int fd, void *buf, size_t nbytes)
  51 {
  52     char *cbuf = (char *)buf;
  53     ssize_t count;
  54     size_t rem = nbytes;
  55
  56     while (rem > 0) {
  57 #ifdef WIN32
  58         count = recv (fd, cbuf, rem, 0);
  59 #else
  60         count = read (fd, cbuf, rem);
  61 #endif
  62         if (count < 0) {
  63             if (errno == EINTR)
  64                 continue;
  65             else
  66                 return count;
  67         } else if (count == 0) {
  68             return count;
  69         }
  70         cbuf += count;
  71         rem -= count;
  72     }
  73     return nbytes;
  74 }