mdw@git.distorted.org.uk Git - fwd/blob - fw.c

   1 /* -*-c-*-
   2  *
   3  * $Id: fw.c,v 1.1 1999/07/01 08:56:23 mdw Exp $
   4  *
   5  * Port forwarding thingy
   6  *
   7  * (c) 1999 Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of the `fw' port forwarder.
  13  *
  14  * `fw' is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * `fw' is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with `fw'; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: fw.c,v $
  32  * Revision 1.1  1999/07/01 08:56:23  mdw
  33  * Initial revision
  34  *
  35  */
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include "config.h"
  40
  41 #include <ctype.h>
  42 #include <errno.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46
  47 #include <unistd.h>
  48 #include <syslog.h>
  49
  50 #include <mLib/mdwopt.h>
  51 #include <mLib/quis.h>
  52 #include <mLib/report.h>
  53 #include <mLib/sel.h>
  54 #include <mLib/sub.h>
  55
  56 #include "acl.h"
  57 #include "bres.h"
  58 #include "conf.h"
  59 #include "listener.h"
  60 #include "scan.h"
  61
  62 /*----- Static variables --------------------------------------------------*/
  63
  64 sel_state *sel;                         /* Multiplexor for nonblocking I/O */
  65
  66 /*----- Main code ---------------------------------------------------------*/
  67
  68 /* --- Standard GNU help options --- */
  69
  70 static void version(FILE *fp)
  71 {
  72   fprintf(fp, "%s version " VERSION "\n", QUIS);
  73 }
  74
  75 static void usage(FILE *fp)
  76 {
  77   fprintf(stderr, "Usage: %s [-d] [-f file] [config statements...]\n",
  78           QUIS);
  79 }
  80
  81 static void help(FILE *fp)
  82 {
  83   version(fp);
  84   fputc('\n', fp);
  85   usage(fp);
  86   fputs("\n\
  87 A fairly full-featured port-forwarder.  Options available are:\n\
  88 \n\
  89 -h, --help              Display this help message.\n\
  90 -v, --version           Display the program's version number.\n\
  91 -u, --usage             Display a terse usage summary.\n\
  92 \n\
  93 -f, --file=FILE         Read configuration from a file.\n\
  94 -d, --dump              Dump the configuration to standard output.\n\
  95 \n\
  96 Configuration may be supplied in one or more configuration files, or on\n\
  97 the command line (or both).  If no `-f' option is present, and no\n\
  98 configuration is given on the command line, the standard input stream is\n\
  99 read.\n\
 100 \n\
 101 Configuration is free-form.  Comments begin with a `#' character and\n\
 102 continue to the end of the line.  When reading from the command line,\n\
 103 each argument is considered a separate line.  See the manual page for the\n\
 104 complete syntax.\n\
 105 ", fp);
 106 }
 107
 108 /* --- @main@ --- *
 109  *
 110  * Arguments:   @int argc@ = number of command line arguments
 111  *              @char *argv[]@ = vector of argument strings
 112  *
 113  * Returns:     ---
 114  *
 115  * Use:         Simple port-forwarding server.
 116  */
 117
 118 int main(int argc, char *argv[])
 119 {
 120   unsigned f = 0;
 121   sel_state sst;
 122
 123   enum {
 124     f_bogus = 1,
 125     f_file = 2,
 126     f_dump = 4,
 127     f_fork = 8
 128   };
 129
 130   /* --- Initialize things --- */
 131
 132   ego(argv[0]);
 133   sel = &sst;
 134   sel_init(sel);
 135   sub_init();
 136   bres_init(sel);
 137
 138   /* --- Parse command line options --- */
 139
 140   for (;;) {
 141     static struct option opts[] = {
 142
 143       /* --- Standard GNU help options --- */
 144
 145       { "help",         0,              0,      'h' },
 146       { "version",      0,              0,      'v' },
 147       { "usage",        0,              0,      'u' },
 148
 149       /* --- Other useful arguments --- */
 150
 151       { "file",         OPTF_ARGREQ,    0,      'f' },
 152       { "dump",         0,              0,      'd' },
 153       { "fork",         0,              0,      'b' },
 154       { "background",   0,              0,      'b' },
 155
 156       /* --- Magic terminator --- */
 157
 158       { 0,              0,              0,      0 }
 159     };
 160     int i = mdwopt(argc, argv, "hvu f:db", opts, 0, 0, 0);
 161
 162     if (i < 0)
 163       break;
 164     switch (i) {
 165       case 'h':
 166         help(stdout);
 167         exit(0);
 168         break;
 169       case 'v':
 170         version(stdout);
 171         exit(0);
 172         break;
 173       case 'u':
 174         usage(stdout);
 175         exit(0);
 176         break;
 177       case 'f': {
 178         scan_filectx ctx;
 179         FILE *fp;
 180         if ((fp = fopen(optarg, "r")) == 0)
 181           die(1, "couldn't open file `%s': %s", optarg, strerror(errno));
 182         scan_fileinit(&ctx, fp, optarg);
 183         conf_parse(&ctx);
 184         fclose(fp);
 185         f |= f_file;
 186       } break;
 187       case 'd':
 188         f |= f_dump;
 189         break;
 190       case 'b':
 191         f |= f_fork;
 192         break;
 193       default:
 194         f |= f_bogus;
 195         break;
 196     }
 197   }
 198
 199   if (f & f_bogus) {
 200     usage(stderr);
 201     exit(1);
 202   }
 203
 204   /* --- Deal with the remaining arguments --- */
 205
 206   if (optind == argc) {
 207     if (f & f_file)
 208       /* Cool */;
 209     else if (isatty(STDIN_FILENO)) {
 210       moan("no configuration given and stdin is a terminal.");
 211       moan("type `%s --help' for usage information.", QUIS);
 212       exit(1);
 213     } else {
 214       scan_filectx ctx;
 215       scan_fileinit(&ctx, stdin, "<stdin>");
 216       conf_parse(&ctx);
 217     }
 218   } else {
 219     scan_argvctx ctx;
 220     scan_argvinit(&ctx, argv + optind);
 221     conf_parse(&ctx);
 222   }
 223
 224   /* --- Dump out the state --- */
 225
 226   if (f & f_dump) {
 227     sel_file *s;
 228     fputs("global acl:\n", stdout);
 229     acl_dump(0, stdout);
 230     for (s = sel->files; s; s = s->next)
 231       listener_dump((listener *)s, stdout);
 232     exit(0);
 233   }
 234
 235   /* --- Fork into the background --- */
 236
 237   if (f & f_fork) {
 238     pid_t kid;
 239
 240     kid = fork();
 241     if (kid == -1)
 242       die(1, "couldn't fork: %s", strerror(errno));
 243     if (kid != 0)
 244       _exit(0);
 245
 246     close(0); close(1); close(2);
 247     setsid();
 248
 249     kid = fork();
 250     if (kid != 0)
 251       _exit(0);
 252   }
 253
 254   /* --- Let rip --- */
 255
 256   openlog(QUIS, 0, LOG_DAEMON);
 257   for (;;)
 258     sel_select(sel);
 259   return (0);
 260 }
 261
 262 /*----- That's all, folks -------------------------------------------------*/