eibd/client/c/openremote.c

   1 /*
   2     EIBD client library
   3     Copyright (C) 2005-2007 Martin Koegler <mkoegler@auto.tuwien.ac.at>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     In addition to the permissions in the GNU General Public License,
  11     you may link the compiled version of this file into combinations
  12     with other programs, and distribute those combinations without any
  13     restriction coming from the use of this file. (The General Public
  14     License restrictions do apply in other respects; for example, they
  15     cover modification of the file, and distribution when not linked into
  16     a combine executable.)
  17
  18     This program is distributed in the hope that it will be useful,
  19     but WITHOUT ANY WARRANTY; without even the implied warranty of
  20     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21     GNU General Public License for more details.
  22
  23     You should have received a copy of the GNU General Public License
  24     along with this program; if not, write to the Free Software
  25     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  26 */
  27
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31 #include <netinet/tcp.h>
  32 #include <netdb.h>
  33
  34 #include "eibclient.h"
  35 #include "eibclient-int.h"
  36
  37 #include "config.h"
  38
  39 /** resolve host name */
  40 static int
  41 GetHostIP (struct sockaddr_in *sock, const char *Name)
  42 {
  43 #ifdef HAVE_GETHOSTBYNAME_R
  44   int len = 2000;
  45   struct hostent host;
  46   char *buf = (char *) malloc (len);
  47   int res;
  48   int err;
  49 #endif
  50   struct hostent *h;
  51   if (!Name)
  52     return 0;
  53   memset (sock, 0, sizeof (*sock));
  54 #ifdef HAVE_GETHOSTBYNAME_R
  55   do
  56     {
  57       res = gethostbyname_r (Name, &host, buf, len, &h, &err);
  58       if (res == ERANGE)
  59         {
  60           len += 2000;
  61           buf = (char *) realloc (buf, len);
  62         }
  63       if (!buf)
  64         return 0;
  65     }
  66   while (res == ERANGE);
  67
  68   if (res || !h)
  69     {
  70       free (buf);
  71       return 0;
  72     }
  73 #else
  74   h = gethostbyname (Name);
  75   if (!h)
  76     return 0;
  77 #endif
  78   sock->sin_family = h->h_addrtype;
  79   sock->sin_addr.s_addr = (*((unsigned long *) h->h_addr_list[0]));
  80 #ifdef HAVE_GETHOSTBYNAME_R
  81   if (buf)
  82     free (buf);
  83 #endif
  84   return 1;
  85 }
  86
  87 EIBConnection *
  88 EIBSocketRemote (const char *host, int port)
  89 {
  90   EIBConnection *con = (EIBConnection *) malloc (sizeof (EIBConnection));
  91   struct sockaddr_in addr;
  92   int val = 1;
  93   if (!con)
  94     {
  95       errno = ENOMEM;
  96       return 0;
  97     }
  98
  99   if (!GetHostIP (&addr, host))
 100     {
 101       free (con);
 102       errno = ECONNREFUSED;
 103       return 0;
 104     }
 105   addr.sin_port = htons (port);
 106
 107   con->fd = socket (addr.sin_family, SOCK_STREAM, 0);
 108   if (con->fd == -1)
 109     {
 110       free (con);
 111       return 0;
 112     }
 113
 114   if (connect (con->fd, (struct sockaddr *) &addr, sizeof (addr)) == -1)
 115     {
 116       int saveerr = errno;
 117       close (con->fd);
 118       free (con);
 119       errno = saveerr;
 120       return 0;
 121     }
 122   setsockopt (con->fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof (val));
 123   con->buflen = 0;
 124   con->buf = 0;
 125   con->readlen = 0;
 126
 127   return con;
 128 }