lib/network.c

   1 /*
   2  * Network library.
   3  * Copyright (C) 1997 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; see the file COPYING; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include <zebra.h>
  23 #include "log.h"
  24 #include "network.h"
  25
  26 /* Read nbytes from fd and store into ptr. */
  27 int
  28 readn (int fd, u_char *ptr, int nbytes)
  29 {
  30   int nleft;
  31   int nread;
  32
  33   nleft = nbytes;
  34
  35   while (nleft > 0)
  36     {
  37       nread = read (fd, ptr, nleft);
  38
  39       if (nread < 0)
  40         return (nread);
  41       else
  42         if (nread == 0)
  43           break;
  44
  45       nleft -= nread;
  46       ptr += nread;
  47     }
  48
  49   return nbytes - nleft;
  50 }
  51
  52 /* Write nbytes from ptr to fd. */
  53 int
  54 writen(int fd, const u_char *ptr, int nbytes)
  55 {
  56   int nleft;
  57   int nwritten;
  58
  59   nleft = nbytes;
  60
  61   while (nleft > 0)
  62     {
  63       nwritten = write(fd, ptr, nleft);
  64
  65       if (nwritten < 0)
  66         {
  67           if (!ERRNO_IO_RETRY(errno))
  68             return nwritten;
  69         }
  70       if (nwritten == 0)
  71         return (nwritten);
  72
  73       nleft -= nwritten;
  74       ptr += nwritten;
  75     }
  76   return nbytes - nleft;
  77 }
  78
  79 int
  80 set_nonblocking(int fd)
  81 {
  82   int flags;
  83
  84   /* According to the Single UNIX Spec, the return value for F_GETFL should
  85      never be negative. */
  86   if ((flags = fcntl(fd, F_GETFL)) < 0)
  87     {
  88       zlog_warn("fcntl(F_GETFL) failed for fd %d: %s",
  89                 fd, safe_strerror(errno));
  90       return -1;
  91     }
  92   if (fcntl(fd, F_SETFL, (flags | O_NONBLOCK)) < 0)
  93     {
  94       zlog_warn("fcntl failed setting fd %d non-blocking: %s",
  95                 fd, safe_strerror(errno));
  96       return -1;
  97     }
  98   return 0;
  99 }
 100
 101 int
 102 set_cloexec(int fd)
 103 {
 104   int flags;
 105   flags = fcntl(fd, F_GETFD, 0);
 106   if (flags == -1)
 107     return -1;
 108
 109   flags |= FD_CLOEXEC;
 110   if (fcntl(fd, F_SETFD, flags) == -1)
 111     return -1;
 112   return 0;
 113 }
 114
 115 float
 116 htonf (float host)
 117 {
 118   u_int32_t lu1, lu2;
 119   float convert;
 120
 121   memcpy (&lu1, &host, sizeof (u_int32_t));
 122   lu2 = htonl (lu1);
 123   memcpy (&convert, &lu2, sizeof (u_int32_t));
 124   return convert;
 125 }
 126
 127 float
 128 ntohf (float net)
 129 {
 130   return htonf (net);
 131 }