citadel/server_main.c

   1 /*
   2  * citserver's main() function lives here.
   3  *
   4  * Copyright (c) 1987-2017 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 #include "ecrash.h"
  32
  33 uid_t ctdluid = 0;
  34 const char *CitadelServiceUDS="citadel-UDS";
  35 const char *CitadelServiceTCP="citadel-TCP";
  36
  37
  38
  39 void go_threading(void);
  40
  41
  42
  43 /*
  44  * Create or remove a lock file, so we only have one Citadel Server running at a time.
  45  */
  46 void ctdl_lockfile(int yo) {
  47         static char lockfilename[SIZ];
  48         static FILE *fp;
  49
  50
  51         if (yo) {
  52                 syslog(LOG_DEBUG, "main: creating lockfile");
  53                 snprintf(lockfilename, sizeof lockfilename, "%s/citadel.lock", ctdl_run_dir);
  54                 fp = fopen(lockfilename, "w");
  55                 if (!fp) {
  56                         syslog(LOG_ERR, "%s: %s", lockfilename, strerror(errno));
  57                         exit(CTDLEXIT_DB);
  58                 }
  59                 if (flock(fileno(fp), (LOCK_EX|LOCK_NB)) != 0) {
  60                         syslog(LOG_ERR, "main: cannot lock %s , is another citserver running?", lockfilename);
  61                         exit(CTDLEXIT_DB);
  62                 }
  63                 return;
  64         }
  65
  66         syslog(LOG_DEBUG, "main: removing lockfile");
  67         unlink(lockfilename);
  68         flock(fileno(fp), LOCK_UN);
  69         fclose(fp);
  70 }
  71
  72
  73
  74
  75
  76
  77 /*
  78  * Here's where it all begins.
  79  */
  80 int main(int argc, char **argv)
  81 {
  82         size_t basesize = 64;
  83         char facility[32];
  84         int a;                  /* General-purpose variables */
  85         struct passwd pw, *pwp = NULL;
  86         char pwbuf[SIZ];
  87         int drop_root_perms = 1;
  88         int relh=0;
  89         int home=0;
  90         int dbg=0;
  91         char relhome[PATH_MAX]="";
  92         char ctdldir[PATH_MAX]=CTDLDIR;
  93         int syslog_facility = LOG_DAEMON;
  94         const char *eDebuglist[] = {NULL, NULL};
  95         uid_t u = 0;
  96         struct passwd *p = NULL;
  97 #ifdef HAVE_RUN_DIR
  98         struct stat filestats;
  99 #endif
 100 #ifdef HAVE_BACKTRACE
 101         eCrashParameters params;
 102 //      eCrashSymbolTable symbol_table;
 103 #endif
 104
 105         /* initialize the master context */
 106         InitializeMasterCC();
 107         InitializeMasterTSD();
 108
 109         /* parse command-line arguments */
 110         while ((a=getopt(argc, argv, "l:dh:x:t:B:Dru:")) != EOF) switch(a) {
 111
 112                 case 'l':
 113                         safestrncpy(facility, optarg, sizeof(facility));
 114                         syslog_facility = SyslogFacility(facility);
 115                         break;
 116
 117                 /* run in the background if -d was specified */
 118                 case 'd':
 119                         running_as_daemon = 1;
 120                         break;
 121
 122                 case 'h':
 123                         relh = optarg[0] != '/';
 124                         if (!relh) {
 125                                 safestrncpy(ctdl_home_directory, optarg, sizeof ctdl_home_directory);
 126                         }
 127                         else {
 128                                 safestrncpy(relhome, optarg, sizeof relhome);
 129                         }
 130                         home=1;
 131                         break;
 132
 133                 case 'x':
 134                         eDebuglist [0] = optarg;
 135                         break;
 136
 137                 case 't':       /* deprecated */
 138                         break;
 139                 case 'B': /* Basesize */
 140                         basesize = atoi(optarg);
 141                         break;
 142
 143                 case 'D':
 144                         dbg = 1;
 145                         break;
 146
 147                 /* -r tells the server not to drop root permissions.
 148                  * Don't use this unless you know what you're doing.
 149                  */
 150                 case 'r':
 151                         drop_root_perms = 0;
 152                         break;
 153
 154                 /* -u tells the server what uid to run under... */
 155                 case 'u':
 156                         u = atoi(optarg);
 157                         if (u > 0) {
 158                                 ctdluid = u;
 159                         }
 160                         else {
 161                                 p = getpwnam(optarg);
 162                                 if (p) {
 163                                         u = p->pw_uid;
 164                                 }
 165                         }
 166                         if (u > 0) {
 167                                 ctdluid = u;
 168                         }
 169                         break;
 170
 171                 default:
 172                 /* any other parameter makes it crash and burn */
 173                         fprintf(stderr, "citserver: usage: "
 174                                         "citserver "
 175                                         "[-l LogFacility] "
 176                                         "[-d] [-D] [-r] "
 177                                         "[-u user] "
 178                                         "[-h HomeDir]\n"
 179                         );
 180                         exit(1);
 181         }
 182
 183         /* Last ditch effort to determine the user name ... if there's a user called "citadel" then use that */
 184         if (ctdluid == 0) {
 185                 p = getpwnam("citadel");
 186                 if (!p) {
 187                         p = getpwnam("bbs");
 188                 }
 189                 if (!p) {
 190                         p = getpwnam("guest");
 191                 }
 192                 if (p) {
 193                         u = p->pw_uid;
 194                 }
 195                 if (u > 0) {
 196                         ctdluid = u;
 197                 }
 198         }
 199
 200         if ((ctdluid == 0) && (drop_root_perms == 0)) {
 201                 fprintf(stderr, "citserver: cannot determine user to run as; please specify -r or -u options\n");
 202                 exit(CTDLEXIT_UNUSER);
 203         }
 204
 205         StartLibCitadel(basesize);
 206         openlog("citserver",
 207                 ( running_as_daemon ? (LOG_PID) : (LOG_PID | LOG_PERROR) ),
 208                 syslog_facility
 209         );
 210
 211         calc_dirs_n_files(relh, home, relhome, ctdldir, dbg);
 212         /* daemonize, if we were asked to */
 213         if (running_as_daemon) {
 214                 start_daemon(0);
 215                 drop_root_perms = 1;
 216         }
 217
 218         /* Tell 'em who's in da house */
 219         syslog(LOG_NOTICE, " ");
 220         syslog(LOG_NOTICE, " ");
 221         syslog(LOG_NOTICE, "*** Citadel server engine ***\n");
 222         syslog(LOG_NOTICE, "Version %d (build %s) ***", REV_LEVEL, svn_revision());
 223         syslog(LOG_NOTICE, "Copyright (C) 1987-2017 by the Citadel development team.");
 224         syslog(LOG_NOTICE, "This program is distributed under the terms of the GNU "
 225                                         "General Public License.");
 226         syslog(LOG_NOTICE, " ");
 227         syslog(LOG_DEBUG, "Called as: %s", argv[0]);
 228         syslog(LOG_INFO, "%s", libcitadel_version_string());
 229
 230 #ifdef HAVE_RUN_DIR
 231         /* on some dists rundir gets purged on startup. so we need to recreate it. */
 232
 233         if (stat(ctdl_run_dir, &filestats)==-1){
 234 #ifdef HAVE_GETPWUID_R
 235 #ifdef SOLARIS_GETPWUID
 236                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 237 #else // SOLARIS_GETPWUID
 238                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 239 #endif // SOLARIS_GETPWUID
 240 #else // HAVE_GETPWUID_R
 241                 pwp = NULL;
 242 #endif // HAVE_GETPWUID_R
 243
 244                 if ((mkdir(ctdl_run_dir, 0755) != 0) && (errno != EEXIST)) {
 245                         syslog(LOG_ERR, "main: unable to create run directory [%s]: %s", ctdl_run_dir, strerror(errno));
 246                 }
 247
 248                 if (chown(ctdl_run_dir, ctdluid, (pwp==NULL)?-1:pw.pw_gid) != 0) {
 249                         syslog(LOG_ERR, "main: unable to set the access rights for [%s]: %s", ctdl_run_dir, strerror(errno));
 250                 }
 251         }
 252 #endif
 253
 254         ctdl_lockfile(1);
 255
 256         /* Initialize... */
 257         init_sysdep();
 258
 259         /*
 260          * Do non system dependent startup functions.
 261          */
 262         master_startup();
 263
 264         /*
 265          * Check that the control record is correct and place sensible values if it isn't
 266          */
 267         check_control();
 268
 269         /*
 270          * Run any upgrade entry points
 271          */
 272         syslog(LOG_INFO, "main: upgrading modules");
 273         upgrade_modules();
 274
 275 /*
 276  * Load the user for the masterCC or create them if they don't exist
 277  */
 278         if (CtdlGetUser(&masterCC.user, "SYS_Citadel"))
 279         {
 280                 /* User doesn't exist. We can't use create user here as the user number needs to be 0 */
 281                 strcpy (masterCC.user.fullname, "SYS_Citadel") ;
 282                 CtdlPutUser(&masterCC.user);
 283                 CtdlGetUser(&masterCC.user, "SYS_Citadel"); /* Just to be safe */
 284         }
 285
 286         /*
 287          * Bind the server to a Unix-domain socket (user client access)
 288          */
 289         CtdlRegisterServiceHook(0,
 290                                 file_citadel_socket,
 291                                 citproto_begin_session,
 292                                 do_command_loop,
 293                                 do_async_loop,
 294                                 CitadelServiceUDS);
 295
 296         /*
 297          * Bind the server to a Unix-domain socket (admin client access)
 298          */
 299         CtdlRegisterServiceHook(0,
 300                                 file_citadel_admin_socket,
 301                                 citproto_begin_admin_session,
 302                                 do_command_loop,
 303                                 do_async_loop,
 304                                 CitadelServiceUDS);
 305         chmod(file_citadel_admin_socket, S_IRWXU);      /* for your eyes only */
 306
 307         /*
 308          * Bind the server to our favorite TCP port (usually 504).
 309          */
 310         CtdlRegisterServiceHook(CtdlGetConfigInt("c_port_number"),
 311                                 NULL,
 312                                 citproto_begin_session,
 313                                 do_command_loop,
 314                                 do_async_loop,
 315                                 CitadelServiceTCP);
 316
 317
 318
 319
 320         /*
 321          * Load any server-side extensions available here.
 322          */
 323         syslog(LOG_INFO, "main: initializing server extensions");
 324
 325         initialise_modules(0);
 326
 327         eDebuglist[1] = getenv("CITADEL_LOGDEBUG");
 328         CtdlSetDebugLogFacilities(eDebuglist, 2);
 329
 330         /*
 331          * If we need host auth, start our chkpwd daemon.
 332          */
 333         if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_HOST) {
 334                 start_chkpwd_daemon();
 335         }
 336
 337
 338         /*
 339          * check, whether we're fired up another time after a crash.
 340          * if, post an aide message, so the admin has a chance to react.
 341          */
 342         checkcrash ();
 343
 344
 345         /*
 346          * Now that we've bound the sockets, change to the Citadel user id and its
 347          * corresponding group ids
 348          */
 349         if (drop_root_perms) {
 350                 cdb_chmod_data();       /* make sure we own our data files */
 351
 352 #ifdef HAVE_GETPWUID_R
 353 #ifdef SOLARIS_GETPWUID
 354                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 355 #else // SOLARIS_GETPWUID
 356                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 357 #endif // SOLARIS_GETPWUID
 358 #else // HAVE_GETPWUID_R
 359                 pwp = NULL;
 360 #endif // HAVE_GETPWUID_R
 361
 362                 if (pwp == NULL)
 363                         syslog(LOG_ERR, "main: WARNING, getpwuid(%ld): %s" "Group IDs will be incorrect.", (long)CTDLUID, strerror(errno));
 364                 else {
 365                         initgroups(pw.pw_name, pw.pw_gid);
 366                         if (setgid(pw.pw_gid))
 367                                 syslog(LOG_ERR, "main: setgid(%ld): %s", (long)pw.pw_gid, strerror(errno));
 368                 }
 369                 syslog(LOG_INFO, "main: changing uid to %ld", (long)CTDLUID);
 370                 if (setuid(CTDLUID) != 0) {
 371                         syslog(LOG_ERR, "main: setuid() failed: %s", strerror(errno));
 372                 }
 373 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 374                 prctl(PR_SET_DUMPABLE, 1);
 375 #endif
 376         }
 377
 378         /* We want to check for idle sessions once per minute */
 379         CtdlRegisterSessionHook(terminate_idle_sessions, EVT_TIMER, PRIO_CLEANUP + 1);
 380
 381         go_threading();
 382
 383         int exit_code = master_cleanup(exit_signal);
 384         ctdl_lockfile(0);
 385         return(exit_code);
 386 }