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 /* Global variable. */
  33 Conf conf;
  34 char *exec_name;
  35
  36 static const char cvsid[] = "$Id: revinetd.c,v 1.29 2008/08/28 03:24:59 necrotaur Exp, adapted by ThP $";
  37
  38 int
  39 main(int argc, char **argv)
  40 {
  41     /* All variables are initialized to a known invalid value so that they
  42        are not used un-initialized. To use them should trip tests or cause
  43        segfaults. */
  44     static struct option long_options[] = {
  45         /* These options set a flag. */
  46         {"help", no_argument, 0, 'h'},
  47         {"daemonize", no_argument, 0, 'd'},
  48         {"relay-agent", no_argument, 0, 'r'},
  49         {"server", no_argument, 0, 's'},
  50         {"listen-client", required_argument, 0, 'c'},
  51         {"listen-relay", required_argument, 0, 'l'},
  52         {"server-host", required_argument, 0, 'b'},
  53         {"target-host", required_argument, 0, 't'},
  54         {"verbose", no_argument, 0, 'v'},
  55         {"quiet", no_argument, 0, 'q'},
  56         {"keep-alive", required_argument, 0, 'k'},
  57         {"access-log", required_argument, 0, 'L'},
  58         {0, 0, 0, 0}};
  59     /* getopt_long stores the option index here. */
  60     int c, option_index = 0;
  61     pid_t pid;
  62
  63     printf("%s - v1.0.2_p6b_20211226 - Copyright (c) 2003-2008 Steven M. Gill, et al (201x, 2020)\n", *argv);
  64     printf("%s is distributed under the terms of the GPL\n", *argv);
  65     printf("http://revinetd.sourceforge.net\n\n");
  66     exec_name = strdup(*argv);
  67
  68     init_conf();
  69
  70     while (1) {
  71         c = getopt_long(argc, argv, "hdrsc:l:b:t:qvk:L:", long_options,
  72                 &option_index);
  73
  74         /* Detect the end of the options. */
  75         if (c == -1)
  76             break;
  77
  78         switch (c) {
  79         case 0:
  80             /* If this option set a flag, do nothing else now. */
  81             if (long_options[option_index].flag != 0)
  82                 break;
  83             printf("option %s", long_options[option_index].name);
  84             if (optarg)
  85                 printf(" with arg %s", optarg);
  86             printf("\n");
  87             break;
  88
  89         case 'd':
  90             conf.daemonize = 1;
  91             conf.verbosity = VB_QUIET;
  92             break;
  93
  94         case 's':
  95             if (conf.server_flag == FLAG_NONE) {
  96                 conf.server_flag = FLAG_SERVER;
  97             } else {
  98                 fprintf(stderr, "You can only set one mode, either Server or "
  99                                 "Relay Agent, not both.\n\n");
 100                 usage();
 101             }
 102             break;
 103
 104         case 'r':
 105             if (conf.server_flag == FLAG_NONE) {
 106                 conf.server_flag = FLAG_RELAY;
 107             } else {
 108                 fprintf(stderr, "You can only set one mode, either Server or "
 109                                 "Relay Agent, not both.\n\n");
 110                 usage();
 111             }
 112             break;
 113
 114         case 'c':
 115             if (conf.server_flag == FLAG_SERVER) {
 116                 conf.host = strdup(optarg);
 117                 conf.port = parse_host_str(conf.host);
 118             } else {
 119                 fprintf(stderr, "You must select Server mode to use -c or "
 120                                 "--listen-client.\n\n");
 121                 usage();
 122             }
 123             break;
 124
 125         case 'l':
 126             if (conf.server_flag == FLAG_SERVER) {
 127                 conf.host2 = strdup(optarg);
 128                 conf.port2 = parse_host_str(conf.host2);
 129             } else {
 130                 fprintf(stderr, "You must select Server mode to use -l or "
 131                                 "--listen-relay.\n\n");
 132                 usage();
 133             }
 134             break;
 135
 136         case 'b':
 137             if (conf.server_flag == FLAG_RELAY) {
 138                 conf.host = strdup(optarg);
 139                 conf.port = parse_host_str(conf.host);
 140             } else {
 141                 fprintf(stderr, "You must select Relay Agent mode to use -c "
 142                                 "or --server-host.\n\n");
 143                 usage();
 144             }
 145             break;
 146
 147         case 't':
 148             if (conf.server_flag == FLAG_RELAY) {
 149                 conf.host2 = strdup(optarg);
 150                 conf.port2 = parse_host_str(conf.host2);
 151             } else {
 152                 fprintf(stderr, "You must select Relay Agent mode to use -t "
 153                                 "or --target-host.\n\n");
 154                 usage();
 155             }
 156             break;
 157         case 'h':
 158             usage();
 159             break;
 160
 161         case 'k':
 162             conf.keepalive = atoi(optarg);
 163             break;
 164
 165         case 'L':
 166             conf.access_log_filepath = strdup(optarg);
 167             break;
 168
 169         case 'v':
 170             if (conf.daemonize == 0) {
 171                 //conf.verbosity = VB_VERBOSE;
 172                 conf.verbosity++;
 173             }
 174             break;
 175
 176         case 'q':
 177             conf.verbosity = VB_QUIET;
 178             break;
 179
 180         case '?':
 181             /* FALL THROUGH */
 182         default:
 183             usage();
 184         }
 185     }
 186
 187     /* Print any remaining command line arguments (not options). */
 188     if (optind < argc) {
 189         usage();
 190     }
 191
 192     if (conf.daemonize == TRUE) {
 193         pid = fork();
 194
 195         if (pid > 0) { /* parent */
 196             exit(0);
 197         } else if (pid < 0) { /* error */
 198             perror("fork");
 199             exit(1);
 200         } /* child */
 201         setsid();
 202
 203         close(0); close(1); close(2);
 204     }
 205
 206     signal(SIGTERM, clean_exit);
 207     signal(SIGINT, clean_exit);
 208     signal(SIGQUIT, clean_exit);
 209     signal(SIGHUP, clean_exit);
 210
 211     if (conf.server_flag == FLAG_SERVER) {
 212         if (conf.port >= 0 && conf.port2 >= 0) {
 213             server(conf.host, conf.port, conf.host2, conf.port2);
 214         } else {
 215             fprintf(stderr, "Two ports, port1 (-c and --client-port) and "
 216                             "port2 (-l and --ra-port) must be "
 217                             "provided.\n\n");
 218             usage();
 219         }
 220     } else if (conf.server_flag == FLAG_RELAY) {
 221         if (conf.host != NULL && conf.host2 != NULL) {
 222             relay_agent(conf.host, conf.port, conf.host2, conf.port2);
 223         } else {
 224             fprintf(stderr, "Both a server (-b and --server-host) and a "
 225                             "target (-t and --target-host)\nmust be "
 226                             "specified.\n\n");
 227             usage();
 228         }
 229     } else {
 230         usage();
 231     }
 232
 233     clean_exit(SIGQUIT);
 234 }
 235
 236 void
 237 usage(void)
 238 {
 239
 240     fprintf(stderr, "Usage: revinetd -s -c HOST1:PORT1 -l HOST2:PORT2 [-d]"
 241                     "\n"
 242                     "       revinetd -r -b HOST1:PORT1 -t "
 243                     "HOST2:PORT2 [-d] [-k seconds]\n"
 244                     "\n"
 245                     "Global arguments:\n"
 246                     "  -s  --server\t\tRuns in server mode\n"
 247                     "  -r  --relay-agent\tRuns as the relay agent\n"
 248                     "  -d  --daemonize\tRuns as a daemon (implies -q)\n"
 249                     "  -L logfile\t\tLog accesses on client-side (of server) to logfile\n"
 250                     "  -h  --help\t\tPrints this message and exit\n"
 251                     "  -q  --quiet\t\tSurpress all messages\n"
 252                     "  -v  --verbose\t\tIncrease verbiosity\n"
 253                     "\n"
 254                     "Server arguments:\n"
 255                     "  -c HOST1:PORT1 --client-port=HOST1:PORT1\tListen for a client on IP and Port\n"
 256                     "  -l HOST2:PORT2 --ra-port=HOST2:PORT2    \tListen for a relay agent on IP and Port\n"
 257                     "Relay agent arguments:\n"
 258                     "  required arguments:\n"
 259                     "  -b HOST1:PORT1 --server-host=HOST1:PORT1\tRevinetd server "
 260                     "host and port\n"
 261                     "  -t HOST2:PORT2 --target-host=HOST2:PORT2\tThe target host "
 262                     "and port\n\n"
 263                     "  optional arguments:\n"
 264                     "  -k seconds --keep-alive=seconds\tKeep-alive signal interval\n"
 265                     "                                 \tdefaults to 180 seconds\n\n");
 266
 267     clean_exit(SIGQUIT);
 268 }
 269
 270 void
 271 clean_exit(int sig)
 272 {
 273     OpenSockets *open_sock;
 274
 275     /* Close all registered sockets. */
 276     open_sock = conf.open_sock;
 277     while (open_sock != NULL) {
 278         if (shutdown(open_sock->sock, SHUT_RDWR) == -1) {
 279             perror("shutdown");
 280         }
 281         close(open_sock->sock);
 282         open_sock = open_sock->next;
 283     }
 284
 285     if (conf.access_log_file != NULL)
 286         fclose(conf.access_log_file);
 287
 288     exit(0);
 289 }
 290
 291 // Adapted to search for the colon from the right. (thpi)
 292 unsigned short
 293 parse_host_str(char *host_str)
 294 {
 295     unsigned short port;
 296     int j;
 297
 298     /* Skip any leading spaces. */
 299     while (isspace(*host_str)) { host_str++; }
 300
 301     /* Loop through the line until we reach a ':'. Exit with errors if we
 302        stumble on an illegal character. */
 303     j = strlen(host_str)-1;
 304     if (j < 0) return 0;
 305     while (*(host_str + j) != ':') {
 306         if (isspace(*(host_str + j))) {
 307             *(host_str + j) = '\0'; // remove the trailing padding
 308         }
 309         --j;
 310         if (j < 0) {
 311             fprintf(stderr, "Invalid hostname format.\n");
 312             usage();
 313         }
 314     }
 315
 316     /* Insert a NUL byte at the position of the right-most ':' to delimitate the
 317        hostname. And then skip ahead one byte. */
 318     *(host_str + j++) = '\0';
 319
 320     /* Grab the port. */
 321     port = (unsigned short)atoi(host_str + j);
 322
 323     return port;
 324 }
 325
 326 void
 327 init_conf(void)
 328 {
 329
 330     memset(&conf, 0, sizeof(Conf));
 331     conf.port = -1;
 332     conf.port2 = -1;
 333     conf.verbosity = VB_NORMAL;
 334     conf.keepalive = 180L;
 335     conf.access_log_filepath = "";
 336     conf.access_log_file = NULL;
 337 }