revinetd.c

   1 /*
   2  * revinetd.c
   3  *
   4  * This file is a part of the revinetd project
   5  *
   6  * Revinetd is copyright (c) 2003-2008 by Steven M. Gill
   7  * and distributed under the GPL.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version 2
  12  * of the License, or (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
  22  * USA.
  23  *
  24  *                                                                        */
  25
  26 #include "includes.h"
  27 #include "revinetd.h"
  28 #include "relay_agt.h"
  29 #include "server.h"
  30 #include "misc.h"
  31
  32 static const char cvsid[] = "$Id: revinetd.c,v 1.29 2008/08/28 03:24:59 necrotaur Exp, adapted by ThP $";
  33
  34 int
  35 main(int argc, char **argv)
  36 {
  37     /* All variables are initialized to a known invalid value so that they
  38        are not used un-initialized. To use them should trip tests or cause
  39        segfaults. */
  40     static struct option long_options[] = {
  41         /* These options set a flag. */
  42         {"help", no_argument, 0, 'h'},
  43         {"daemonize", no_argument, 0, 'd'},
  44         {"relay-agent", no_argument, 0, 'r'},
  45         {"server", no_argument, 0, 's'},
  46         {"listen-client", required_argument, 0, 'c'},
  47         {"listen-relay", required_argument, 0, 'l'},
  48         {"server-host", required_argument, 0, 'b'},
  49         {"target-host", required_argument, 0, 't'},
  50         {"verbose", no_argument, 0, 'v'},
  51         {"quiet", no_argument, 0, 'q'},
  52         {"keep-alive", required_argument, 0, 'k'},
  53         {0, 0, 0, 0}};
  54     /* getopt_long stores the option index here. */
  55     int c, option_index = 0;
  56     pid_t pid;
  57
  58     printf("%s - v1.0.2_p5_20200612 - Copyright (c) 2003-2008 Steven M. Gill, et al (201x, 2020)\n", *argv);
  59     printf("%s is distributed under the terms of the GPL\n", *argv);
  60     printf("http://revinetd.sourceforge.net\n\n");
  61     exec_name = strdup(*argv);
  62
  63     init_conf();
  64
  65     while (1) {
  66         c = getopt_long(argc, argv, "hdrsc:l:b:t:qvk:", long_options,
  67                 &option_index);
  68
  69         /* Detect the end of the options. */
  70         if (c == -1)
  71             break;
  72
  73         switch (c) {
  74         case 0:
  75             /* If this option set a flag, do nothing else now. */
  76             if (long_options[option_index].flag != 0)
  77                 break;
  78             printf("option %s", long_options[option_index].name);
  79             if (optarg)
  80                 printf(" with arg %s", optarg);
  81             printf("\n");
  82             break;
  83
  84         case 'd':
  85             conf.daemonize = 1;
  86             conf.verbosity = VB_QUIET;
  87             break;
  88
  89         case 's':
  90             if (conf.server_flag == FLAG_NONE) {
  91                 conf.server_flag = FLAG_SERVER;
  92             } else {
  93                 fprintf(stderr, "You can only set one mode, either Server or "
  94                                 "Relay Agent, not both.\n\n");
  95                 usage();
  96             }
  97             break;
  98
  99         case 'r':
 100             if (conf.server_flag == FLAG_NONE) {
 101                 conf.server_flag = FLAG_RELAY;
 102             } else {
 103                 fprintf(stderr, "You can only set one mode, either Server or "
 104                                 "Relay Agent, not both.\n\n");
 105                 usage();
 106             }
 107             break;
 108
 109         case 'c':
 110             if (conf.server_flag == FLAG_SERVER) {
 111                 conf.host = strdup(optarg);
 112                 conf.port = parse_host_str(conf.host);
 113             } else {
 114                 fprintf(stderr, "You must select Server mode to use -c or "
 115                                 "--listen-client.\n\n");
 116                 usage();
 117             }
 118             break;
 119
 120         case 'l':
 121             if (conf.server_flag == FLAG_SERVER) {
 122                 conf.host2 = strdup(optarg);
 123                 conf.port2 = parse_host_str(conf.host2);
 124             } else {
 125                 fprintf(stderr, "You must select Server mode to use -l or "
 126                                 "--listen-relay.\n\n");
 127                 usage();
 128             }
 129             break;
 130
 131         case 'b':
 132             if (conf.server_flag == FLAG_RELAY) {
 133                 conf.host = strdup(optarg);
 134                 conf.port = parse_host_str(conf.host);
 135             } else {
 136                 fprintf(stderr, "You must select Relay Agent mode to use -c "
 137                                 "or --server-host.\n\n");
 138                 usage();
 139             }
 140             break;
 141
 142         case 't':
 143             if (conf.server_flag == FLAG_RELAY) {
 144                 conf.host2 = strdup(optarg);
 145                 conf.port2 = parse_host_str(conf.host2);
 146             } else {
 147                 fprintf(stderr, "You must select Relay Agent mode to use -t "
 148                                 "or --target-host.\n\n");
 149                 usage();
 150             }
 151             break;
 152         case 'h':
 153             usage();
 154             break;
 155
 156         case 'k':
 157             conf.keepalive = atoi(optarg);
 158             break;
 159
 160         case 'v':
 161             if (conf.daemonize == 0) {
 162                 //conf.verbosity = VB_VERBOSE;
 163                 conf.verbosity++;
 164             }
 165             break;
 166
 167         case 'q':
 168             conf.verbosity = VB_QUIET;
 169             break;
 170
 171         case '?':
 172             /* FALL THROUGH */
 173         default:
 174             usage();
 175         }
 176     }
 177
 178     /* Print any remaining command line arguments (not options). */
 179     if (optind < argc) {
 180         usage();
 181     }
 182
 183     if (conf.daemonize == TRUE) {
 184         pid = fork();
 185
 186         if (pid > 0) { /* parent */
 187             exit(0);
 188         } else if (pid < 0) { /* error */
 189             perror("fork");
 190             exit(1);
 191         } /* child */
 192         setsid();
 193
 194         close(0); close(1); close(2);
 195     }
 196
 197     signal(SIGTERM, clean_exit);
 198     signal(SIGINT, clean_exit);
 199     signal(SIGQUIT, clean_exit);
 200     signal(SIGHUP, clean_exit);
 201
 202     if (conf.server_flag == FLAG_SERVER) {
 203         if (conf.port >= 0 && conf.port2 >= 0) {
 204             server(conf.host, conf.port, conf.host2, conf.port2);
 205         } else {
 206             fprintf(stderr, "Two ports, port1 (-l and --client-port) and "
 207                             "port2 (-L and --ra-port) must be "
 208                             "provided.\n\n");
 209             usage();
 210         }
 211     } else if (conf.server_flag == FLAG_RELAY) {
 212         if (conf.host != NULL && conf.host2 != NULL) {
 213             relay_agent(conf.host, conf.port, conf.host2, conf.port2);
 214         } else {
 215             fprintf(stderr, "Both a server (-b and --server-host) and a "
 216                             "target (-t and --target-host)\nmust be "
 217                             "specified.\n\n");
 218             usage();
 219         }
 220     } else {
 221         usage();
 222     }
 223
 224     exit(0);
 225 }
 226
 227 void
 228 usage(void)
 229 {
 230
 231     fprintf(stderr, "Usage: revinetd -s -c HOST1:PORT1 -l HOST2:PORT2 [-d]"
 232                     "\n"
 233                     "       revinetd -r -b HOST1:PORT1 -t "
 234                     "HOST2:PORT2 [-d] [-k seconds]\n"
 235                     "\n"
 236                     "Global arguments:\n"
 237                     "  -s  --server\t\tRuns in server mode\n"
 238                     "  -r  --relay-agent\tRuns as the relay agent\n"
 239                     "  -d  --daemonize\tRuns as a daemon (implies -q)\n"
 240                     "  -h  --help\t\tPrints this message and exit\n"
 241                     "  -q  --quiet\t\tSurpress all messages\n"
 242                     "  -v  --verbose\t\tIncrease verbiosity\n"
 243                     "\n"
 244                     "Server arguments:\n"
 245                     "  -c HOST1:PORT1 --client-port=HOST1:PORT1\tListen for a client on IP and Port\n"
 246                     "  -l HOST2:PORT2 --ra-port=HOST2:PORT2    \tListen for a relay agent on IP and Port\n"
 247                     "Relay agent arguments:\n"
 248                     "  required arguments:\n"
 249                     "  -b HOST1:PORT1 --server-host=HOST1:PORT1\tRevinetd server "
 250                     "host and port\n"
 251                     "  -t HOST2:PORT2 --target-host=HOST2:PORT2\tThe target host "
 252                     "and port\n\n"
 253                     "  optional arguments:\n"
 254                     "  -k seconds --keep-alive=seconds\tKeep-alive signal interval\n"
 255                     "                                 \tdefaults to 180 seconds\n\n");
 256
 257     clean_exit(SIGQUIT);
 258 }
 259
 260 void
 261 clean_exit(int sig)
 262 {
 263     OpenSockets *open_sock;
 264
 265     /* Close all registered sockets. */
 266     open_sock = conf.open_sock;
 267     while (open_sock != NULL) {
 268         if (shutdown(open_sock->sock, SHUT_RDWR) == -1) {
 269             perror("shutdown");
 270         }
 271         close(open_sock->sock);
 272         open_sock = open_sock->next;
 273     }
 274
 275     exit(0);
 276 }
 277
 278 // Adapted to search for the colon from the right. (thpi)
 279 unsigned short
 280 parse_host_str(char *host_str)
 281 {
 282     unsigned short port;
 283     int j;
 284
 285     /* Skip any leading spaces. */
 286     while (isspace(*host_str)) { host_str++; }
 287
 288     /* Loop through the line until we reach a ':'. Exit with errors if we
 289        stumble on an illegal character. */
 290     j = strlen(host_str)-1;
 291     if (j < 0) return 0;
 292     while (*(host_str + j) != ':') {
 293         if (isspace(*(host_str + j))) {
 294             *(host_str + j) = '\0'; // remove the trailing padding
 295         }
 296         --j;
 297         if (j < 0) {
 298             fprintf(stderr, "Invalid hostname format.\n");
 299             usage();
 300         }
 301     }
 302
 303     /* Insert a NUL byte at the position of the right-most ':' to delimitate the
 304        hostname. And then skip ahead one byte. */
 305     *(host_str + j++) = '\0';
 306
 307     /* Grab the port. */
 308     port = (unsigned short)atoi(host_str + j);
 309
 310     return port;
 311 }
 312
 313 void
 314 init_conf(void)
 315 {
 316
 317     memset(&conf, 0, sizeof(Conf));
 318     conf.port = -1;
 319     conf.port2 = -1;
 320     conf.verbosity = VB_NORMAL;
 321     conf.keepalive = 180L;
 322 }