citadel/server_main.c

   1 /*
   2  * citserver's main() function lives here.
   3  *
   4  * Copyright (c) 1987-2018 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 void go_threading(void);
  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 #ifdef HAVE_BACKTRACE
  92         eCrashParameters params;
  93 //      eCrashSymbolTable symbol_table;
  94 #endif
  95
  96         /* initialize the master context */
  97         InitializeMasterCC();
  98         InitializeMasterTSD();
  99
 100         /* parse command-line arguments */
 101         while ((a=getopt(argc, argv, "l:dh:x:t:B:Dru:")) != EOF) switch(a) {
 102
 103                 case 'l':
 104                         safestrncpy(facility, optarg, sizeof(facility));
 105                         syslog_facility = SyslogFacility(facility);
 106                         break;
 107
 108                 /* run in the background if -d was specified */
 109                 case 'd':
 110                         running_as_daemon = 1;
 111                         break;
 112
 113                 case 'h':
 114                         relh = optarg[0] != '/';
 115                         if (!relh) {
 116                                 safestrncpy(ctdl_home_directory, optarg, sizeof ctdl_home_directory);
 117                         }
 118                         else {
 119                                 safestrncpy(relhome, optarg, sizeof relhome);
 120                         }
 121                         home=1;
 122                         break;
 123
 124                 case 'x':
 125                         max_log_level = atoi(optarg);
 126                         break;
 127
 128                 case 't':       /* deprecated */
 129                         break;
 130                 case 'B': /* Basesize */
 131                         basesize = atoi(optarg);
 132                         break;
 133
 134                 case 'D':
 135                         dbg = 1;
 136                         break;
 137
 138                 /* -r tells the server not to drop root permissions.
 139                  * Don't use this unless you know what you're doing.
 140                  */
 141                 case 'r':
 142                         drop_root_perms = 0;
 143                         break;
 144
 145                 /* -u tells the server what uid to run under... */
 146                 case 'u':
 147                         u = atoi(optarg);
 148                         if (u > 0) {
 149                                 ctdluid = u;
 150                         }
 151                         else {
 152                                 p = getpwnam(optarg);
 153                                 if (p) {
 154                                         u = p->pw_uid;
 155                                 }
 156                         }
 157                         if (u > 0) {
 158                                 ctdluid = u;
 159                         }
 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) 1987-2018 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
 254         /* Initialize... */
 255         init_sysdep();
 256
 257         /*
 258          * Do non system dependent startup functions.
 259          */
 260         master_startup();
 261
 262         /*
 263          * Check that the control record is correct and place sensible values if it isn't
 264          */
 265         check_control();
 266
 267         /*
 268          * Run any upgrade entry points
 269          */
 270         syslog(LOG_INFO, "main: upgrading modules");
 271         upgrade_modules();
 272
 273 /*
 274  * Load the user for the masterCC or create them if they don't exist
 275  */
 276         if (CtdlGetUser(&masterCC.user, "SYS_Citadel"))
 277         {
 278                 /* User doesn't exist. We can't use create user here as the user number needs to be 0 */
 279                 strcpy (masterCC.user.fullname, "SYS_Citadel") ;
 280                 CtdlPutUser(&masterCC.user);
 281                 CtdlGetUser(&masterCC.user, "SYS_Citadel"); /* Just to be safe */
 282         }
 283
 284         /*
 285          * Bind the server to a Unix-domain socket (user client access)
 286          */
 287         CtdlRegisterServiceHook(0,
 288                                 file_citadel_socket,
 289                                 citproto_begin_session,
 290                                 do_command_loop,
 291                                 do_async_loop,
 292                                 CitadelServiceUDS);
 293
 294         /*
 295          * Bind the server to a Unix-domain socket (admin client access)
 296          */
 297         CtdlRegisterServiceHook(0,
 298                                 file_citadel_admin_socket,
 299                                 citproto_begin_admin_session,
 300                                 do_command_loop,
 301                                 do_async_loop,
 302                                 CitadelServiceUDS);
 303         chmod(file_citadel_admin_socket, S_IRWXU);      /* for your eyes only */
 304
 305         /*
 306          * Bind the server to our favorite TCP port (usually 504).
 307          */
 308         CtdlRegisterServiceHook(CtdlGetConfigInt("c_port_number"),
 309                                 NULL,
 310                                 citproto_begin_session,
 311                                 do_command_loop,
 312                                 do_async_loop,
 313                                 CitadelServiceTCP);
 314
 315
 316
 317
 318         /*
 319          * Load any server-side extensions available here.
 320          */
 321         syslog(LOG_INFO, "main: initializing server extensions");
 322
 323         initialise_modules(0);
 324
 325         /*
 326          * If we need host auth, start our chkpwd daemon.
 327          */
 328         if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_HOST) {
 329                 start_chkpwd_daemon();
 330         }
 331
 332         /*
 333          * check, whether we're fired up another time after a crash.
 334          * if, post an aide message, so the admin has a chance to react.
 335          */
 336         checkcrash();
 337
 338         /*
 339          * Now that we've bound the sockets, change to the Citadel user id and its
 340          * corresponding group ids
 341          */
 342         if (drop_root_perms) {
 343                 cdb_chmod_data();       /* make sure we own our data files */
 344
 345 #ifdef HAVE_GETPWUID_R
 346 #ifdef SOLARIS_GETPWUID
 347                 pwp = getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf));
 348 #else // SOLARIS_GETPWUID
 349                 getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 350 #endif // SOLARIS_GETPWUID
 351 #else // HAVE_GETPWUID_R
 352                 pwp = NULL;
 353 #endif // HAVE_GETPWUID_R
 354
 355                 if (pwp == NULL)
 356                         syslog(LOG_ERR, "main: WARNING, getpwuid(%ld): %m Group IDs will be incorrect.", (long)CTDLUID);
 357                 else {
 358                         initgroups(pw.pw_name, pw.pw_gid);
 359                         if (setgid(pw.pw_gid))
 360                                 syslog(LOG_ERR, "main: setgid(%ld): %m", (long)pw.pw_gid);
 361                 }
 362                 syslog(LOG_INFO, "main: changing uid to %ld", (long)CTDLUID);
 363                 if (setuid(CTDLUID) != 0) {
 364                         syslog(LOG_ERR, "main: setuid() failed: %m");
 365                 }
 366 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 367                 prctl(PR_SET_DUMPABLE, 1);
 368 #endif
 369         }
 370
 371         /* We want to check for idle sessions once per minute */
 372         CtdlRegisterSessionHook(terminate_idle_sessions, EVT_TIMER, PRIO_CLEANUP + 1);
 373
 374         go_threading();
 375
 376         int exit_code = master_cleanup(exit_signal);
 377         ctdl_lockfile(0);
 378         return(exit_code);
 379 }