citadel/server_main.c

   1 /*
   2  * citserver's main() function lives here.
   3  *
   4  * Copyright (c) 1987-2020 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, "l:dh:x:t:B:Dru:s:")) != EOF) switch(a) {
  97
  98                 case 'l':
  99                         safestrncpy(facility, optarg, sizeof(facility));
 100                         syslog_facility = SyslogFacility(facility);
 101                         break;
 102
 103                 /* run in the background if -d was specified */
 104                 case 'd':
 105                         running_as_daemon = 1;
 106                         break;
 107
 108                 case 'h':
 109                         relh = optarg[0] != '/';
 110                         if (!relh) {
 111                                 safestrncpy(ctdl_home_directory, optarg, sizeof ctdl_home_directory);
 112                         }
 113                         else {
 114                                 safestrncpy(relhome, optarg, sizeof relhome);
 115                         }
 116                         home=1;
 117                         break;
 118
 119                 case 'x':
 120                         max_log_level = atoi(optarg);
 121                         break;
 122
 123                 case 't':       /* deprecated */
 124                         break;
 125                 case 'B': /* Basesize */
 126                         basesize = atoi(optarg);
 127                         break;
 128
 129                 case 'D':
 130                         dbg = 1;
 131                         break;
 132
 133                 /* -r tells the server not to drop root permissions.
 134                  * Don't use this unless you know what you're doing.
 135                  */
 136                 case 'r':
 137                         drop_root_perms = 0;
 138                         break;
 139
 140                 /* -u tells the server what uid to run under... */
 141                 case 'u':
 142                         u = atoi(optarg);
 143                         if (u > 0) {
 144                                 ctdluid = u;
 145                         }
 146                         else {
 147                                 p = getpwnam(optarg);
 148                                 if (p) {
 149                                         u = p->pw_uid;
 150                                 }
 151                         }
 152                         if (u > 0) {
 153                                 ctdluid = u;
 154                         }
 155                         break;
 156
 157                 /* -s tells the server to behave differently during sanity checks */
 158                 case 's':
 159                         sanity_diag_mode = atoi(optarg);
 160                         break;
 161
 162                 default:
 163                 /* any other parameter makes it crash and burn */
 164                         fprintf(stderr, "citserver: usage: "
 165                                         "citserver "
 166                                         "[-l LogFacility] "
 167                                         "[-x MaxLogLevel] "
 168                                         "[-d] [-D] [-r] "
 169                                         "[-u user] "
 170                                         "[-h HomeDir]\n"
 171                         );
 172                         exit(1);
 173         }
 174
 175         /* Last ditch effort to determine the user name ... if there's a user called "citadel" then use that */
 176         if (ctdluid == 0) {
 177                 p = getpwnam("citadel");
 178                 if (!p) {
 179                         p = getpwnam("bbs");
 180                 }
 181                 if (!p) {
 182                         p = getpwnam("guest");
 183                 }
 184                 if (p) {
 185                         u = p->pw_uid;
 186                 }
 187                 if (u > 0) {
 188                         ctdluid = u;
 189                 }
 190         }
 191
 192         if ((ctdluid == 0) && (drop_root_perms == 0)) {
 193                 fprintf(stderr, "citserver: cannot determine user to run as; please specify -r or -u options\n");
 194                 exit(CTDLEXIT_UNUSER);
 195         }
 196
 197         StartLibCitadel(basesize);
 198         setlogmask(LOG_UPTO(max_log_level));
 199         openlog("citserver",
 200                 ( running_as_daemon ? (LOG_PID) : (LOG_PID | LOG_PERROR) ),
 201                 syslog_facility
 202         );
 203
 204         calc_dirs_n_files(relh, home, relhome, ctdldir, dbg);
 205         /* daemonize, if we were asked to */
 206         if (running_as_daemon) {
 207                 start_daemon(0);
 208                 drop_root_perms = 1;
 209         }
 210
 211         /* Tell 'em who's in da house */
 212         syslog(LOG_INFO, " ");
 213         syslog(LOG_INFO, " ");
 214         syslog(LOG_INFO, "*** Citadel server engine ***\n");
 215         syslog(LOG_INFO, "Version %d (build %s) ***", REV_LEVEL, svn_revision());
 216         syslog(LOG_INFO, "Copyright (C) 1987-2020 by the Citadel development team.");
 217         syslog(LOG_INFO, " ");
 218         syslog(LOG_INFO, "This program is open source software: you can redistribute it and/or");
 219         syslog(LOG_INFO, "modify it under the terms of the GNU General Public License, version 3.");
 220         syslog(LOG_INFO, " ");
 221         syslog(LOG_INFO, "This program is distributed in the hope that it will be useful,");
 222         syslog(LOG_INFO, "but WITHOUT ANY WARRANTY; without even the implied warranty of");
 223         syslog(LOG_INFO, "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the");
 224         syslog(LOG_INFO, "GNU General Public License for more details.");
 225         syslog(LOG_INFO, " ");
 226         syslog(LOG_INFO, "%s", libcitadel_version_string());
 227
 228 #ifdef HAVE_RUN_DIR
 229         /* on some dists rundir gets purged on startup. so we need to recreate it. */
 230
 231         if (stat(ctdl_run_dir, &filestats) == -1) {
 232 #ifdef HAVE_GETPWUID_R
 233 #ifdef SOLARIS_GETPWUID
 234                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 235 #else // SOLARIS_GETPWUID
 236                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 237 #endif // SOLARIS_GETPWUID
 238 #else // HAVE_GETPWUID_R
 239                 pwp = NULL;
 240 #endif // HAVE_GETPWUID_R
 241
 242                 if ((mkdir(ctdl_run_dir, 0755) != 0) && (errno != EEXIST)) {
 243                         syslog(LOG_ERR, "main: unable to create run directory [%s]: %m", ctdl_run_dir);
 244                 }
 245
 246                 if (chown(ctdl_run_dir, ctdluid, (pwp==NULL)?-1:pw.pw_gid) != 0) {
 247                         syslog(LOG_ERR, "main: unable to set the access rights for [%s]: %m", ctdl_run_dir);
 248                 }
 249         }
 250 #endif
 251
 252         ctdl_lockfile(1);
 253         init_sysdep();                                          // Initialize...
 254         master_startup();                                       // Do non system dependent startup functions
 255         check_control();                                        // Check/sanitize/initialize control record, fix user indexes
 256         syslog(LOG_INFO, "main: upgrading modules");            // Run any upgrade entry points
 257         upgrade_modules();
 258
 259 /*
 260  * Load the user for the masterCC or create them if they don't exist
 261  */
 262         if (CtdlGetUser(&masterCC.user, "SYS_Citadel"))
 263         {
 264                 /* User doesn't exist. We can't use create user here as the user number needs to be 0 */
 265                 strcpy (masterCC.user.fullname, "SYS_Citadel") ;
 266                 CtdlPutUser(&masterCC.user);
 267                 CtdlGetUser(&masterCC.user, "SYS_Citadel"); /* Just to be safe */
 268         }
 269
 270         /*
 271          * Bind the server to a Unix-domain socket (user client access)
 272          */
 273         CtdlRegisterServiceHook(0,
 274                                 file_citadel_socket,
 275                                 citproto_begin_session,
 276                                 do_command_loop,
 277                                 do_async_loop,
 278                                 CitadelServiceUDS);
 279
 280         /*
 281          * Bind the server to a Unix-domain socket (admin client access)
 282          */
 283         CtdlRegisterServiceHook(0,
 284                                 file_citadel_admin_socket,
 285                                 citproto_begin_admin_session,
 286                                 do_command_loop,
 287                                 do_async_loop,
 288                                 CitadelServiceUDS);
 289         chmod(file_citadel_admin_socket, S_IRWXU);      /* for your eyes only */
 290
 291         /*
 292          * Bind the server to our favorite TCP port (usually 504).
 293          */
 294         CtdlRegisterServiceHook(CtdlGetConfigInt("c_port_number"),
 295                                 NULL,
 296                                 citproto_begin_session,
 297                                 do_command_loop,
 298                                 do_async_loop,
 299                                 CitadelServiceTCP);
 300
 301         /*
 302          * Load any server-side extensions available here.
 303          */
 304         syslog(LOG_INFO, "main: initializing server extensions");
 305
 306         initialise_modules(0);
 307
 308         /*
 309          * If we need host auth, start our chkpwd daemon.
 310          */
 311         if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_HOST) {
 312                 start_chkpwd_daemon();
 313         }
 314
 315         /*
 316          * check, whether we're fired up another time after a crash.
 317          * if, post an aide message, so the admin has a chance to react.
 318          */
 319         checkcrash();
 320
 321         /*
 322          * Now that we've bound the sockets, change to the Citadel user id and its
 323          * corresponding group ids
 324          */
 325         if (drop_root_perms) {
 326                 cdb_chmod_data();       /* make sure we own our data files */
 327
 328 #ifdef HAVE_GETPWUID_R
 329 #ifdef SOLARIS_GETPWUID
 330                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 331 #else // SOLARIS_GETPWUID
 332                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 333 #endif // SOLARIS_GETPWUID
 334 #else // HAVE_GETPWUID_R
 335                 pwp = NULL;
 336 #endif // HAVE_GETPWUID_R
 337
 338                 if (pwp == NULL)
 339                         syslog(LOG_ERR, "main: WARNING, getpwuid(%ld): %m Group IDs will be incorrect.", (long)CTDLUID);
 340                 else {
 341                         initgroups(pw.pw_name, pw.pw_gid);
 342                         if (setgid(pw.pw_gid))
 343                                 syslog(LOG_ERR, "main: setgid(%ld): %m", (long)pw.pw_gid);
 344                 }
 345                 syslog(LOG_INFO, "main: changing uid to %ld", (long)CTDLUID);
 346                 if (setuid(CTDLUID) != 0) {
 347                         syslog(LOG_ERR, "main: setuid() failed: %m");
 348                 }
 349 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 350                 prctl(PR_SET_DUMPABLE, 1);
 351 #endif
 352         }
 353
 354         /* We want to check for idle sessions once per minute */
 355         CtdlRegisterSessionHook(terminate_idle_sessions, EVT_TIMER, PRIO_CLEANUP + 1);
 356
 357         go_threading();
 358
 359         int exit_code = master_cleanup(exit_signal);
 360         ctdl_lockfile(0);
 361         if (restart_server) {
 362                 execv(argv[0], argv);
 363         }
 364         return(exit_code);
 365 }