citadel/server_main.c

   1 /*
   2  * citserver's main() function lives here.
   3  *
   4  * Copyright (c) 1987-2019 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 void go_threading(void);
  36 int sanity_diag_mode = 0;
  37
  38
  39 /*
  40  * Create or remove a lock file, so we only have one Citadel Server running at a time.
  41  */
  42 void ctdl_lockfile(int yo) {
  43         static char lockfilename[SIZ];
  44         static FILE *fp;
  45
  46         if (yo) {
  47                 syslog(LOG_DEBUG, "main: creating lockfile");
  48                 snprintf(lockfilename, sizeof lockfilename, "%s/citadel.lock", ctdl_run_dir);
  49                 fp = fopen(lockfilename, "w");
  50                 if (!fp) {
  51                         syslog(LOG_ERR, "%s: %m", lockfilename);
  52                         exit(CTDLEXIT_DB);
  53                 }
  54                 if (flock(fileno(fp), (LOCK_EX|LOCK_NB)) != 0) {
  55                         syslog(LOG_ERR, "main: cannot lock %s , is another citserver running?", lockfilename);
  56                         exit(CTDLEXIT_DB);
  57                 }
  58                 return;
  59         }
  60
  61         syslog(LOG_DEBUG, "main: removing lockfile");
  62         unlink(lockfilename);
  63         flock(fileno(fp), LOCK_UN);
  64         fclose(fp);
  65 }
  66
  67
  68 /*
  69  * Here's where it all begins.
  70  */
  71 int main(int argc, char **argv)
  72 {
  73         size_t basesize = 64;
  74         char facility[32];
  75         int a;                  /* General-purpose variables */
  76         struct passwd pw, *pwp = NULL;
  77         char pwbuf[SIZ];
  78         int drop_root_perms = 1;
  79         int relh=0;
  80         int home=0;
  81         int dbg=0;
  82         int max_log_level = LOG_INFO;
  83         char relhome[PATH_MAX]="";
  84         char ctdldir[PATH_MAX]=CTDLDIR;
  85         int syslog_facility = LOG_DAEMON;
  86         uid_t u = 0;
  87         struct passwd *p = NULL;
  88 #ifdef HAVE_RUN_DIR
  89         struct stat filestats;
  90 #endif
  91
  92         /* initialize the master context */
  93         InitializeMasterCC();
  94         InitializeMasterTSD();
  95
  96         /* parse command-line arguments */
  97         while ((a=getopt(argc, argv, "l:dh:x:t:B:Dru:s:")) != EOF) switch(a) {
  98
  99                 case 'l':
 100                         safestrncpy(facility, optarg, sizeof(facility));
 101                         syslog_facility = SyslogFacility(facility);
 102                         break;
 103
 104                 /* run in the background if -d was specified */
 105                 case 'd':
 106                         running_as_daemon = 1;
 107                         break;
 108
 109                 case 'h':
 110                         relh = optarg[0] != '/';
 111                         if (!relh) {
 112                                 safestrncpy(ctdl_home_directory, optarg, sizeof ctdl_home_directory);
 113                         }
 114                         else {
 115                                 safestrncpy(relhome, optarg, sizeof relhome);
 116                         }
 117                         home=1;
 118                         break;
 119
 120                 case 'x':
 121                         max_log_level = atoi(optarg);
 122                         break;
 123
 124                 case 't':       /* deprecated */
 125                         break;
 126                 case 'B': /* Basesize */
 127                         basesize = atoi(optarg);
 128                         break;
 129
 130                 case 'D':
 131                         dbg = 1;
 132                         break;
 133
 134                 /* -r tells the server not to drop root permissions.
 135                  * Don't use this unless you know what you're doing.
 136                  */
 137                 case 'r':
 138                         drop_root_perms = 0;
 139                         break;
 140
 141                 /* -u tells the server what uid to run under... */
 142                 case 'u':
 143                         u = atoi(optarg);
 144                         if (u > 0) {
 145                                 ctdluid = u;
 146                         }
 147                         else {
 148                                 p = getpwnam(optarg);
 149                                 if (p) {
 150                                         u = p->pw_uid;
 151                                 }
 152                         }
 153                         if (u > 0) {
 154                                 ctdluid = u;
 155                         }
 156                         break;
 157
 158                 /* -s tells the server to behave differently during sanity checks */
 159                 case 's':
 160                         sanity_diag_mode = atoi(optarg);
 161                         break;
 162
 163                 default:
 164                 /* any other parameter makes it crash and burn */
 165                         fprintf(stderr, "citserver: usage: "
 166                                         "citserver "
 167                                         "[-l LogFacility] "
 168                                         "[-x MaxLogLevel] "
 169                                         "[-d] [-D] [-r] "
 170                                         "[-u user] "
 171                                         "[-h HomeDir]\n"
 172                         );
 173                         exit(1);
 174         }
 175
 176         /* Last ditch effort to determine the user name ... if there's a user called "citadel" then use that */
 177         if (ctdluid == 0) {
 178                 p = getpwnam("citadel");
 179                 if (!p) {
 180                         p = getpwnam("bbs");
 181                 }
 182                 if (!p) {
 183                         p = getpwnam("guest");
 184                 }
 185                 if (p) {
 186                         u = p->pw_uid;
 187                 }
 188                 if (u > 0) {
 189                         ctdluid = u;
 190                 }
 191         }
 192
 193         if ((ctdluid == 0) && (drop_root_perms == 0)) {
 194                 fprintf(stderr, "citserver: cannot determine user to run as; please specify -r or -u options\n");
 195                 exit(CTDLEXIT_UNUSER);
 196         }
 197
 198         StartLibCitadel(basesize);
 199         setlogmask(LOG_UPTO(max_log_level));
 200         openlog("citserver",
 201                 ( running_as_daemon ? (LOG_PID) : (LOG_PID | LOG_PERROR) ),
 202                 syslog_facility
 203         );
 204
 205         calc_dirs_n_files(relh, home, relhome, ctdldir, dbg);
 206         /* daemonize, if we were asked to */
 207         if (running_as_daemon) {
 208                 start_daemon(0);
 209                 drop_root_perms = 1;
 210         }
 211
 212         /* Tell 'em who's in da house */
 213         syslog(LOG_INFO, " ");
 214         syslog(LOG_INFO, " ");
 215         syslog(LOG_INFO, "*** Citadel server engine ***\n");
 216         syslog(LOG_INFO, "Version %d (build %s) ***", REV_LEVEL, svn_revision());
 217         syslog(LOG_INFO, "Copyright (C) 1987-2019 by the Citadel development team.");
 218         syslog(LOG_INFO, " ");
 219         syslog(LOG_INFO, "This program is open source software: you can redistribute it and/or");
 220         syslog(LOG_INFO, "modify it under the terms of the GNU General Public License, version 3.");
 221         syslog(LOG_INFO, " ");
 222         syslog(LOG_INFO, "This program is distributed in the hope that it will be useful,");
 223         syslog(LOG_INFO, "but WITHOUT ANY WARRANTY; without even the implied warranty of");
 224         syslog(LOG_INFO, "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the");
 225         syslog(LOG_INFO, "GNU General Public License for more details.");
 226         syslog(LOG_INFO, " ");
 227         syslog(LOG_INFO, "%s", libcitadel_version_string());
 228
 229 #ifdef HAVE_RUN_DIR
 230         /* on some dists rundir gets purged on startup. so we need to recreate it. */
 231
 232         if (stat(ctdl_run_dir, &filestats) == -1) {
 233 #ifdef HAVE_GETPWUID_R
 234 #ifdef SOLARIS_GETPWUID
 235                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 236 #else // SOLARIS_GETPWUID
 237                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 238 #endif // SOLARIS_GETPWUID
 239 #else // HAVE_GETPWUID_R
 240                 pwp = NULL;
 241 #endif // HAVE_GETPWUID_R
 242
 243                 if ((mkdir(ctdl_run_dir, 0755) != 0) && (errno != EEXIST)) {
 244                         syslog(LOG_ERR, "main: unable to create run directory [%s]: %m", ctdl_run_dir);
 245                 }
 246
 247                 if (chown(ctdl_run_dir, ctdluid, (pwp==NULL)?-1:pw.pw_gid) != 0) {
 248                         syslog(LOG_ERR, "main: unable to set the access rights for [%s]: %m", ctdl_run_dir);
 249                 }
 250         }
 251 #endif
 252
 253         ctdl_lockfile(1);
 254
 255         /* Initialize... */
 256         init_sysdep();
 257
 258         /*
 259          * Do non system dependent startup functions.
 260          */
 261         master_startup();
 262
 263         /*
 264          * Check that the control record is correct and place sensible values if it isn't
 265          */
 266         check_control();
 267
 268         /*
 269          * Run any upgrade entry points
 270          */
 271         syslog(LOG_INFO, "main: upgrading modules");
 272         upgrade_modules();
 273
 274 /*
 275  * Load the user for the masterCC or create them if they don't exist
 276  */
 277         if (CtdlGetUser(&masterCC.user, "SYS_Citadel"))
 278         {
 279                 /* User doesn't exist. We can't use create user here as the user number needs to be 0 */
 280                 strcpy (masterCC.user.fullname, "SYS_Citadel") ;
 281                 CtdlPutUser(&masterCC.user);
 282                 CtdlGetUser(&masterCC.user, "SYS_Citadel"); /* Just to be safe */
 283         }
 284
 285         /*
 286          * Bind the server to a Unix-domain socket (user client access)
 287          */
 288         CtdlRegisterServiceHook(0,
 289                                 file_citadel_socket,
 290                                 citproto_begin_session,
 291                                 do_command_loop,
 292                                 do_async_loop,
 293                                 CitadelServiceUDS);
 294
 295         /*
 296          * Bind the server to a Unix-domain socket (admin client access)
 297          */
 298         CtdlRegisterServiceHook(0,
 299                                 file_citadel_admin_socket,
 300                                 citproto_begin_admin_session,
 301                                 do_command_loop,
 302                                 do_async_loop,
 303                                 CitadelServiceUDS);
 304         chmod(file_citadel_admin_socket, S_IRWXU);      /* for your eyes only */
 305
 306         /*
 307          * Bind the server to our favorite TCP port (usually 504).
 308          */
 309         CtdlRegisterServiceHook(CtdlGetConfigInt("c_port_number"),
 310                                 NULL,
 311                                 citproto_begin_session,
 312                                 do_command_loop,
 313                                 do_async_loop,
 314                                 CitadelServiceTCP);
 315
 316
 317
 318
 319         /*
 320          * Load any server-side extensions available here.
 321          */
 322         syslog(LOG_INFO, "main: initializing server extensions");
 323
 324         initialise_modules(0);
 325
 326         /*
 327          * If we need host auth, start our chkpwd daemon.
 328          */
 329         if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_HOST) {
 330                 start_chkpwd_daemon();
 331         }
 332
 333         /*
 334          * check, whether we're fired up another time after a crash.
 335          * if, post an aide message, so the admin has a chance to react.
 336          */
 337         checkcrash();
 338
 339         /*
 340          * Now that we've bound the sockets, change to the Citadel user id and its
 341          * corresponding group ids
 342          */
 343         if (drop_root_perms) {
 344                 cdb_chmod_data();       /* make sure we own our data files */
 345
 346 #ifdef HAVE_GETPWUID_R
 347 #ifdef SOLARIS_GETPWUID
 348                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 349 #else // SOLARIS_GETPWUID
 350                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 351 #endif // SOLARIS_GETPWUID
 352 #else // HAVE_GETPWUID_R
 353                 pwp = NULL;
 354 #endif // HAVE_GETPWUID_R
 355
 356                 if (pwp == NULL)
 357                         syslog(LOG_ERR, "main: WARNING, getpwuid(%ld): %m Group IDs will be incorrect.", (long)CTDLUID);
 358                 else {
 359                         initgroups(pw.pw_name, pw.pw_gid);
 360                         if (setgid(pw.pw_gid))
 361                                 syslog(LOG_ERR, "main: setgid(%ld): %m", (long)pw.pw_gid);
 362                 }
 363                 syslog(LOG_INFO, "main: changing uid to %ld", (long)CTDLUID);
 364                 if (setuid(CTDLUID) != 0) {
 365                         syslog(LOG_ERR, "main: setuid() failed: %m");
 366                 }
 367 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 368                 prctl(PR_SET_DUMPABLE, 1);
 369 #endif
 370         }
 371
 372         /* We want to check for idle sessions once per minute */
 373         CtdlRegisterSessionHook(terminate_idle_sessions, EVT_TIMER, PRIO_CLEANUP + 1);
 374
 375         go_threading();
 376
 377         int exit_code = master_cleanup(exit_signal);
 378         ctdl_lockfile(0);
 379         return(exit_code);
 380 }