dccp.c

   1 /*
   2  * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file dccp.c common functions of the dccp sender/receiver */
  20
  21 /*
  22  * based on common.c of dccp-cs-0.01.tar.bz2,
  23  * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
  24  */
  25
  26 #include "para.h"
  27 #include "error.h"
  28 #include "dccp.h"
  29
  30 /** \cond some magic dccp constants */
  31 #define SOL_DCCP 269
  32 #define SOCK_DCCP 6
  33 #define IPPROTO_DCCP 33
  34 #define DCCP_SOCKOPT_PACKET_SIZE 1
  35 #define DCCP_SOCKOPT_SERVICE 2
  36 /** \endcond */
  37
  38 /**
  39  * obtain a dccp socket for sending/receiving
  40  *
  41  * \return the file descriptor of the new socket or \p -E_DCCP_SOCKET
  42  * on errors.
  43  */
  44 int dccp_get_socket(void)
  45 {
  46         int s = socket(AF_INET, SOCK_DCCP, IPPROTO_DCCP);
  47
  48         if (s < 0)
  49                 return -E_DCCP_SOCKET;
  50         return s;
  51 }
  52
  53 /**
  54  * prepare a dccp socket
  55  *
  56  * \param fd the file descriptor of the socket
  57  *
  58  * \returns positive on success, negative on errors.
  59  */
  60 int dccp_set_socket(int fd)
  61 {
  62         int pkt_size = 256, ret;
  63
  64         /* hack to get a service code */
  65         ret = setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_PACKET_SIZE,
  66                 (char*)&pkt_size, sizeof(pkt_size));
  67         if (ret < 0)
  68                 return -E_DCCP_PACKET_SIZE;
  69         ret = setsockopt(fd, SOL_DCCP, DCCP_SOCKOPT_SERVICE,
  70                 (char*)&pkt_size, sizeof(pkt_size));
  71         if (ret < 0)
  72                 return -E_DCCP_SERVICE;
  73         return 1;
  74 }