citadel/server_main.c

   1 /*
   2  * citserver's main() function lives here.
   3  *
   4  * Copyright (c) 1987-2021 by the citadel.org team
   5  *
   6  * This program is open source software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 3.
   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 #include <stdlib.h>
  15 #include <unistd.h>
  16 #include <stdio.h>
  17 #include <sys/types.h>
  18 #include <sys/stat.h>
  19 #include <grp.h>
  20 #include <sys/file.h>
  21 #include <libcitadel.h>
  22
  23 #include "citserver.h"
  24 #include "svn_revision.h"
  25 #include "modules_init.h"
  26 #include "config.h"
  27 #include "control.h"
  28 #include "serv_extensions.h"
  29 #include "citadel_dirs.h"
  30 #include "user_ops.h"
  31
  32 uid_t ctdluid = 0;
  33 const char *CitadelServiceUDS="citadel-UDS";
  34 const char *CitadelServiceTCP="citadel-TCP";
  35 int sanity_diag_mode = 0;
  36
  37
  38 /*
  39  * Create or remove a lock file, so we only have one Citadel Server running at a time.
  40  */
  41 void ctdl_lockfile(int yo) {
  42         static char lockfilename[PATH_MAX];
  43         static FILE *fp;
  44
  45         if (yo) {
  46                 syslog(LOG_DEBUG, "main: creating lockfile");
  47                 snprintf(lockfilename, sizeof lockfilename, "%s/citadel.lock", ctdl_run_dir);
  48                 fp = fopen(lockfilename, "w");
  49                 if (!fp) {
  50                         syslog(LOG_ERR, "%s: %m", lockfilename);
  51                         exit(CTDLEXIT_DB);
  52                 }
  53                 if (flock(fileno(fp), (LOCK_EX|LOCK_NB)) != 0) {
  54                         syslog(LOG_ERR, "main: cannot lock %s , is another citserver running?", lockfilename);
  55                         exit(CTDLEXIT_DB);
  56                 }
  57                 return;
  58         }
  59
  60         syslog(LOG_DEBUG, "main: removing lockfile");
  61         unlink(lockfilename);
  62         flock(fileno(fp), LOCK_UN);
  63         fclose(fp);
  64 }
  65
  66
  67 /*
  68  * Here's where it all begins.
  69  */
  70 int main(int argc, char **argv)
  71 {
  72         size_t basesize = 64;
  73         char facility[32];
  74         int a;                  /* General-purpose variables */
  75         struct passwd pw, *pwp = NULL;
  76         char pwbuf[SIZ];
  77         int drop_root_perms = 1;
  78         int relh=0;
  79         int home=0;
  80         int dbg=0;
  81         int max_log_level = LOG_INFO;
  82         char relhome[PATH_MAX]="";
  83         char ctdldir[PATH_MAX]=CTDLDIR;
  84         int syslog_facility = LOG_DAEMON;
  85         uid_t u = 0;
  86         struct passwd *p = NULL;
  87 #ifdef HAVE_RUN_DIR
  88         struct stat filestats;
  89 #endif
  90
  91         /* initialize the master context */
  92         InitializeMasterCC();
  93         InitializeMasterTSD();
  94
  95         /* parse command-line arguments */
  96         while ((a=getopt(argc, argv, "cl:dh:x:t:B:Dru:s:")) != EOF) switch(a) {
  97
  98                 // test this binary for compatibility and exit
  99                 case 'c':
 100                         fprintf(stderr, "%s: binary compatibility confirmed\n", argv[0]);
 101                         exit(0);
 102                         break;
 103
 104                 // identify the desired syslog facility
 105                 case 'l':
 106                         safestrncpy(facility, optarg, sizeof(facility));
 107                         syslog_facility = SyslogFacility(facility);
 108                         break;
 109
 110                 // run in the background if -d was specified
 111                 case 'd':
 112                         running_as_daemon = 1;
 113                         break;
 114
 115                 // specify the data directory
 116                 case 'h':
 117                         relh = optarg[0] != '/';
 118                         if (!relh) {
 119                                 safestrncpy(ctdl_home_directory, optarg, sizeof ctdl_home_directory);
 120                         }
 121                         else {
 122                                 safestrncpy(relhome, optarg, sizeof relhome);
 123                         }
 124                         home=1;
 125                         break;
 126
 127                 // identify the desired logging severity level
 128                 case 'x':
 129                         max_log_level = atoi(optarg);
 130                         break;
 131
 132                 // deprecated
 133                 case 't':
 134                         break;
 135
 136                 // basesize (what is this?)
 137                 case 'B':
 138                         basesize = atoi(optarg);
 139                         break;
 140
 141                 case 'D':
 142                         dbg = 1;
 143                         break;
 144
 145                 // -r tells the server not to drop root permissions.
 146                 // Don't use this unless you know what you're doing.
 147                 case 'r':
 148                         drop_root_perms = 0;
 149                         break;
 150
 151                 // -u tells the server what uid to run under...
 152                 case 'u':
 153                         u = atoi(optarg);
 154                         if (u > 0) {
 155                                 ctdluid = u;
 156                         }
 157                         else {
 158                                 p = getpwnam(optarg);
 159                                 if (p) {
 160                                         u = p->pw_uid;
 161                                 }
 162                         }
 163                         if (u > 0) {
 164                                 ctdluid = u;
 165                         }
 166                         break;
 167
 168                 // -s tells the server to behave differently during sanity checks
 169                 case 's':
 170                         sanity_diag_mode = atoi(optarg);
 171                         break;
 172
 173                 // any other parameter makes it crash and burn
 174                 default:
 175                         fprintf(stderr, "citserver: usage: "
 176                                         "citserver "
 177                                         "[-l LogFacility] "
 178                                         "[-x MaxLogLevel] "
 179                                         "[-d] [-D] [-r] "
 180                                         "[-u user] "
 181                                         "[-h HomeDir]\n"
 182                         );
 183                         exit(1);
 184         }
 185
 186         /* Last ditch effort to determine the user name ... if there's a user called "citadel" then use that */
 187         if (ctdluid == 0) {
 188                 p = getpwnam("citadel");
 189                 if (!p) {
 190                         p = getpwnam("bbs");
 191                 }
 192                 if (!p) {
 193                         p = getpwnam("guest");
 194                 }
 195                 if (p) {
 196                         u = p->pw_uid;
 197                 }
 198                 if (u > 0) {
 199                         ctdluid = u;
 200                 }
 201         }
 202
 203         if ((ctdluid == 0) && (drop_root_perms == 0)) {
 204                 fprintf(stderr, "citserver: cannot determine user to run as; please specify -r or -u options\n");
 205                 exit(CTDLEXIT_UNUSER);
 206         }
 207
 208         StartLibCitadel(basesize);
 209         setlogmask(LOG_UPTO(max_log_level));
 210         openlog("citserver",
 211                 ( running_as_daemon ? (LOG_PID) : (LOG_PID | LOG_PERROR) ),
 212                 syslog_facility
 213         );
 214
 215         calc_dirs_n_files(relh, home, relhome, ctdldir, dbg);
 216         /* daemonize, if we were asked to */
 217         if (running_as_daemon) {
 218                 start_daemon(0);
 219                 drop_root_perms = 1;
 220         }
 221
 222         /* Tell 'em who's in da house */
 223         syslog(LOG_INFO, " ");
 224         syslog(LOG_INFO, " ");
 225         syslog(LOG_INFO, "*** Citadel server engine ***\n");
 226         syslog(LOG_INFO, "Version %d (build %s) ***", REV_LEVEL, svn_revision());
 227         syslog(LOG_INFO, "Copyright (C) 1987-2021 by the Citadel development team.");
 228         syslog(LOG_INFO, " ");
 229         syslog(LOG_INFO, "This program is open source software: you can redistribute it and/or");
 230         syslog(LOG_INFO, "modify it under the terms of the GNU General Public License, version 3.");
 231         syslog(LOG_INFO, " ");
 232         syslog(LOG_INFO, "This program is distributed in the hope that it will be useful,");
 233         syslog(LOG_INFO, "but WITHOUT ANY WARRANTY; without even the implied warranty of");
 234         syslog(LOG_INFO, "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the");
 235         syslog(LOG_INFO, "GNU General Public License for more details.");
 236         syslog(LOG_INFO, " ");
 237         syslog(LOG_INFO, "%s", libcitadel_version_string());
 238
 239 #ifdef HAVE_RUN_DIR
 240         /* on some dists rundir gets purged on startup. so we need to recreate it. */
 241
 242         if (stat(ctdl_run_dir, &filestats) == -1) {
 243 #ifdef HAVE_GETPWUID_R
 244 #ifdef SOLARIS_GETPWUID
 245                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 246 #else // SOLARIS_GETPWUID
 247                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 248 #endif // SOLARIS_GETPWUID
 249 #else // HAVE_GETPWUID_R
 250                 pwp = NULL;
 251 #endif // HAVE_GETPWUID_R
 252
 253                 if ((mkdir(ctdl_run_dir, 0755) != 0) && (errno != EEXIST)) {
 254                         syslog(LOG_ERR, "main: unable to create run directory [%s]: %m", ctdl_run_dir);
 255                 }
 256
 257                 if (chown(ctdl_run_dir, ctdluid, (pwp==NULL)?-1:pw.pw_gid) != 0) {
 258                         syslog(LOG_ERR, "main: unable to set the access rights for [%s]: %m", ctdl_run_dir);
 259                 }
 260         }
 261 #endif
 262
 263         ctdl_lockfile(1);
 264         init_sysdep();                                          // Initialize...
 265         master_startup();                                       // Do non system dependent startup functions
 266         check_control();                                        // Check/sanitize/initialize control record, fix user indexes
 267         syslog(LOG_INFO, "main: upgrading modules");            // Run any upgrade entry points
 268         upgrade_modules();
 269
 270 /*
 271  * Load the user for the masterCC or create them if they don't exist
 272  */
 273         if (CtdlGetUser(&masterCC.user, "SYS_Citadel"))
 274         {
 275                 /* User doesn't exist. We can't use create user here as the user number needs to be 0 */
 276                 strcpy (masterCC.user.fullname, "SYS_Citadel") ;
 277                 CtdlPutUser(&masterCC.user);
 278                 CtdlGetUser(&masterCC.user, "SYS_Citadel"); /* Just to be safe */
 279         }
 280
 281         /*
 282          * Bind the server to a Unix-domain socket (user client access)
 283          */
 284         CtdlRegisterServiceHook(0,
 285                                 file_citadel_socket,
 286                                 citproto_begin_session,
 287                                 do_command_loop,
 288                                 do_async_loop,
 289                                 CitadelServiceUDS);
 290
 291         /*
 292          * Bind the server to a Unix-domain socket (admin client access)
 293          */
 294         CtdlRegisterServiceHook(0,
 295                                 file_citadel_admin_socket,
 296                                 citproto_begin_admin_session,
 297                                 do_command_loop,
 298                                 do_async_loop,
 299                                 CitadelServiceUDS);
 300         chmod(file_citadel_admin_socket, S_IRWXU);      /* for your eyes only */
 301
 302         /*
 303          * Bind the server to our favorite TCP port (usually 504).
 304          */
 305         CtdlRegisterServiceHook(CtdlGetConfigInt("c_port_number"),
 306                                 NULL,
 307                                 citproto_begin_session,
 308                                 do_command_loop,
 309                                 do_async_loop,
 310                                 CitadelServiceTCP);
 311
 312         /*
 313          * Load any server-side extensions available here.
 314          */
 315         syslog(LOG_INFO, "main: initializing server extensions");
 316
 317         initialise_modules(0);
 318
 319         /*
 320          * If we need host auth, start our chkpwd daemon.
 321          */
 322         if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_HOST) {
 323                 start_chkpwd_daemon();
 324         }
 325
 326         /*
 327          * check, whether we're fired up another time after a crash.
 328          * if, post an aide message, so the admin has a chance to react.
 329          */
 330         checkcrash();
 331
 332         /*
 333          * Now that we've bound the sockets, change to the Citadel user id and its
 334          * corresponding group ids
 335          */
 336         if (drop_root_perms) {
 337                 cdb_chmod_data();       /* make sure we own our data files */
 338
 339 #ifdef HAVE_GETPWUID_R
 340 #ifdef SOLARIS_GETPWUID
 341                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 342 #else // SOLARIS_GETPWUID
 343                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 344 #endif // SOLARIS_GETPWUID
 345 #else // HAVE_GETPWUID_R
 346                 pwp = NULL;
 347 #endif // HAVE_GETPWUID_R
 348
 349                 if (pwp == NULL)
 350                         syslog(LOG_ERR, "main: WARNING, getpwuid(%ld): %m Group IDs will be incorrect.", (long)CTDLUID);
 351                 else {
 352                         initgroups(pw.pw_name, pw.pw_gid);
 353                         if (setgid(pw.pw_gid))
 354                                 syslog(LOG_ERR, "main: setgid(%ld): %m", (long)pw.pw_gid);
 355                 }
 356                 syslog(LOG_INFO, "main: changing uid to %ld", (long)CTDLUID);
 357                 if (setuid(CTDLUID) != 0) {
 358                         syslog(LOG_ERR, "main: setuid() failed: %m");
 359                 }
 360 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 361                 prctl(PR_SET_DUMPABLE, 1);
 362 #endif
 363         }
 364
 365         /* We want to check for idle sessions once per minute */
 366         CtdlRegisterSessionHook(terminate_idle_sessions, EVT_TIMER, PRIO_CLEANUP + 1);
 367
 368         go_threading();
 369
 370         int exit_code = master_cleanup(exit_signal);
 371         ctdl_lockfile(0);
 372         if (restart_server) {
 373                 syslog(LOG_INFO, "main:    *** CITADEL SERVER IS RESTARTING ***");
 374                 execv(argv[0], argv);
 375         }
 376         return(exit_code);
 377 }