mnc.tproj/mnc_opts.c

   1 /*
   2  * $Id: mnc_opts.c,v 1.3 2004/09/22 16:02:26 colmmacc Exp $
   3  *
   4  * mnc_opts.c -- Multicast NetCat
   5  *
   6  * Colm MacCarthaigh, <colm@apache.org>
   7  *
   8  * Copyright (c) 2007, Colm MacCarthaigh.
   9  * Copyright (c) 2004 - 2006, HEAnet Ltd.
  10  *
  11  * This software is an open source.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  *
  17  * Redistributions of source code must retain the above copyright notice,
  18  * this list of conditions and the following disclaimer.
  19  *
  20  * Redistributions in binary form must reproduce the above copyright notice,
  21  * this list of conditions and the following disclaimer in the documentation
  22  * and/or other materials provided with the distribution.
  23  *
  24  * Neither the name of the HEAnet Ltd. nor the names of its contributors may
  25  * be used to endorse or promote products derived from this software without
  26  * specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  30  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  31  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
  32  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  33  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  34  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  35  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  36  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  37  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38  * POSSIBILITY OF SUCH DAMAGE.
  39  *
  40  */
  41
  42 #include <stdlib.h>
  43 #include <stdio.h>
  44 #include <string.h>
  45
  46 #ifndef WINDOWS
  47
  48 /* UNIX-y includes */
  49 #include <sys/types.h>
  50 #include <sys/socket.h>
  51 #include <netdb.h>
  52 #else
  53
  54 /* WINDOWS-y includes */
  55 #include <winsock2.h>
  56 #include <ws2tcpip.h>
  57 #endif
  58
  59 #include "mnc.h"
  60
  61 /* Display a usage statement */
  62 void usage(void)
  63 {
  64         fprintf(stderr,
  65                 "Usage: mnc [-l] [-i interface] [-p port] group-id "
  66                 "[source-address]\n\n"
  67                 "-l :    listen mode\n"
  68                 "-i :    specify interface to listen\n"
  69                 "-p :    specify port to listen/send on\n\n");
  70         exit(1);
  71 }
  72
  73 struct mnc_configuration * parse_arguments(int argc, char **argv)
  74 {
  75         /* Utility variables */
  76         int                                     optind,
  77                                                 errorcode;
  78         struct  addrinfo                        hints;
  79
  80         /* Our persisting configuration */
  81         static  struct mnc_configuration        config;
  82
  83         /* Set some defaults */
  84         config.mode     = SENDER;
  85         config.port     = MNC_DEFAULT_PORT;
  86         config.iface    = NULL;
  87         config.source   = NULL;
  88
  89         /* Loop through the arguments */
  90         for (optind = 1; optind < (argc - 1); optind++)
  91         {
  92                 if ( (argv[optind][0] == '-') || (argv[optind][0] == '/') )
  93                 {
  94                         switch(argv[optind][1])
  95                         {
  96                                 /* Set listening mode */
  97                                 case 'l':       config.mode = LISTENER;
  98                                                 break;
  99
 100                                 /* Set port */
 101                                 case 'p':       config.port = argv[++optind];
 102                                                 break;
 103
 104                                 /* Set an interface */
 105                                 case 'i':       config.iface = argv[++optind];
 106                                                 break;
 107
 108                                 /* Unrecognised option */
 109                                 default:        usage();
 110                                                 break;
 111                         }
 112                 }
 113                 else
 114                 {
 115                         /* assume we've ran out of options */
 116                         break;
 117                 }
 118         }
 119
 120         /* There's a chance we were passed one option */
 121         if (optind >= argc || argv[optind][0] == '-')
 122         {
 123                 usage();
 124         }
 125
 126         /* Now make sure we have either exactly 1 or 2 more arguments */
 127         if ( (argc - optind) != 1 && (argc - optind) != 2 )
 128         {
 129                 /* We have not been given the right ammount of
 130                    arguments */
 131                 usage();
 132         }
 133
 134         /* You can't have an interface without also listening */
 135         if (config.mode == SENDER && config.iface != NULL)
 136         {
 137                 mnc_error("You may only specify the interface when in"
 138                                 " listening mode\n");
 139         }
 140
 141         /* Set some hints for getaddrinfo */
 142         memset(&hints, 0, sizeof(hints));
 143
 144         /* We want a UDP socket */
 145         hints.ai_socktype = SOCK_DGRAM;
 146
 147         /* Don't do any name-lookups */
 148         hints.ai_flags = AI_NUMERICHOST;
 149
 150         /* Get the group-id information */
 151         if ( (errorcode =
 152               getaddrinfo(argv[optind], config.port, &hints, &config.group)) != 0)
 153         {
 154                 mnc_error("Error getting group-id address information: %s\n",
 155                           gai_strerror(errorcode));
 156         }
 157
 158         /* Move on to next argument */
 159         optind++;
 160
 161         /* Get the source information */
 162         if ( (argc - optind) == 1)
 163         {
 164
 165                 if ( (errorcode =
 166                       getaddrinfo(argv[optind], config.port, &hints, &config.source))
 167                     != 0)
 168                 {
 169                         mnc_error("Error getting source-address information: %s\n",
 170                                   gai_strerror(errorcode));
 171                 }
 172
 173                 /* Confirm that the source and group are in the same Address Family */
 174                 if ( config.source->ai_family != config.group->ai_family )
 175                 {
 176                         mnc_error("Group ID and Source address are not of "
 177                                   "the same type\n");
 178                 }
 179         }
 180
 181         return &config;
 182 }