citadel/server/server_main.c

   1 // citserver's main() function lives here.
   2 //
   3 // Copyright (c) 1987-2023 by the citadel.org team
   4 //
   5 // This program is open source software; you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License version 3.
   7
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10 #include <stdio.h>
  11 #include <sys/types.h>
  12 #include <sys/stat.h>
  13 #include <grp.h>
  14 #include <sys/file.h>
  15 #include <libcitadel.h>
  16 #include "citserver.h"
  17 #include "modules_init.h"
  18 #include "config.h"
  19 #include "control.h"
  20 #include "serv_extensions.h"
  21 #include "citadel_dirs.h"
  22 #include "user_ops.h"
  23
  24 uid_t ctdluid = 0;
  25 const char *CitadelServiceUDS="citadel-UDS";
  26 const char *CitadelServiceTCP="citadel-TCP";
  27 int sanity_diag_mode = 0;
  28 char *rescue_string = NULL;
  29
  30
  31 // Create or remove a lock file, so we only have one Citadel Server running at a time.
  32 // Set 'op' to nonzero to lock, zero to unlock.
  33 void ctdl_lockfile(int op) {
  34         static char lockfilename[PATH_MAX];
  35         static FILE *fp;
  36
  37         if (op) {
  38                 syslog(LOG_DEBUG, "main: creating lockfile");
  39                 snprintf(lockfilename, sizeof lockfilename, "%s/citadel.lock", ctdl_run_dir);
  40                 fp = fopen(lockfilename, "w");
  41                 if (!fp) {
  42                         syslog(LOG_ERR, "%s: %m", lockfilename);
  43                         exit(CTDLEXIT_DB);
  44                 }
  45                 if (flock(fileno(fp), (LOCK_EX|LOCK_NB)) != 0) {
  46                         syslog(LOG_ERR, "main: cannot lock %s (is another citserver running?)", lockfilename);
  47                         exit(CTDLEXIT_DB);
  48                 }
  49                 fprintf(fp, "%d\n", getpid());
  50                 fflush(fp);
  51                 return;
  52         }
  53
  54         syslog(LOG_DEBUG, "main: removing lockfile");
  55         unlink(lockfilename);
  56         flock(fileno(fp), LOCK_UN);
  57         fclose(fp);
  58 }
  59
  60
  61 // Here's where it all begins.
  62 int main(int argc, char **argv) {
  63
  64         char facility[32];
  65         struct passwd pw, *pwp = NULL;
  66         char pwbuf[SIZ];
  67         int drop_root_perms = 1;
  68         int max_log_level = LOG_INFO;
  69         char *ctdldir = CTDLDIR;
  70         int syslog_facility = LOG_DAEMON;
  71         uid_t u = 0;
  72         struct passwd *p = NULL;
  73 #ifdef HAVE_RUN_DIR
  74         struct stat filestats;
  75 #endif
  76
  77         // Tell 'em who's in da house
  78         syslog(LOG_INFO, " ");
  79         syslog(LOG_INFO, " ");
  80         syslog(LOG_INFO, "*** Citadel server engine ***\n");
  81         syslog(LOG_INFO, "Version %d (build %s) ***", REV_LEVEL, BUILD_ID);
  82         syslog(LOG_INFO, "Copyright (C) 1987-2023 by the Citadel development team.");
  83         syslog(LOG_INFO, " ");
  84         syslog(LOG_INFO, "This program is open source software.  Use, duplication, or disclosure");
  85         syslog(LOG_INFO, "is subject to the terms of the GNU General Public License, version 3.");
  86         syslog(LOG_INFO, " ");
  87         syslog(LOG_INFO, "%s", libcitadel_version_string());
  88
  89         // parse command-line arguments
  90         int g;
  91         while ((g=getopt(argc, argv, "cl:h:x:t:B:Dru:s:R:")) != EOF) switch(g) {
  92
  93                 // test this binary for compatibility and exit
  94                 case 'c':
  95                         fprintf(stderr, "%s: binary compatibility confirmed\n", argv[0]);
  96                         exit(0);
  97                         break;
  98
  99                 // identify the desired syslog facility
 100                 case 'l':
 101                         safestrncpy(facility, optarg, sizeof(facility));
 102                         syslog_facility = SyslogFacility(facility);
 103                         break;
 104
 105                 // specify the data directory
 106                 case 'h':
 107                         ctdldir = optarg;
 108                         break;
 109
 110                 // identify the desired logging severity level
 111                 case 'x':
 112                         max_log_level = atoi(optarg);
 113                         break;
 114
 115                 // -r tells the server not to drop root permissions.
 116                 // Don't use this unless you know what you're doing.
 117                 case 'r':
 118                         drop_root_perms = 0;
 119                         break;
 120
 121                 // -u tells the server what uid to run under...
 122                 case 'u':
 123                         u = atoi(optarg);
 124                         if (u > 0) {
 125                                 ctdluid = u;
 126                         }
 127                         else {
 128                                 p = getpwnam(optarg);
 129                                 if (p) {
 130                                         u = p->pw_uid;
 131                                 }
 132                         }
 133                         if (u > 0) {
 134                                 ctdluid = u;
 135                         }
 136                         break;
 137
 138                 // -s tells the server to behave differently during sanity checks
 139                 case 's':
 140                         sanity_diag_mode = atoi(optarg);
 141                         break;
 142
 143                 // -R is an undocumented rescue mode that you should never use
 144                 case 'R':
 145                         rescue_string = strdup(optarg);
 146                         break;
 147
 148                 // any other parameter makes it crash and burn
 149                 default:
 150                         fprintf(stderr, "citserver: usage: "
 151                                         "citserver "
 152                                         "[-l LogFacility] "
 153                                         "[-x MaxLogLevel] "
 154                                         "[-d] [-r] "
 155                                         "[-u user] "
 156                                         "[-h HomeDir]\n"
 157                         );
 158                         exit(1);
 159         }
 160
 161         if (chdir(ctdldir) != 0) {
 162                 syslog(LOG_ERR, "main: unable to change directory to [%s]: %m", ctdldir);
 163                 exit(CTDLEXIT_HOME);
 164         }
 165         else {
 166                 syslog(LOG_INFO, "main: running in data directory %s", ctdldir);
 167         }
 168
 169         if ((ctdluid == 0) && (drop_root_perms == 0)) {
 170                 fprintf(stderr, "citserver: cannot determine user to run as; please specify -r or -u options\n");
 171                 exit(CTDLEXIT_UNUSER);
 172         }
 173
 174         // Last ditch effort to determine the user name ... if there's a user called "citadel" then use that
 175         if (ctdluid == 0) {
 176                 p = getpwnam("citadel");
 177                 if (!p) {
 178                         p = getpwnam("bbs");
 179                 }
 180                 if (!p) {
 181                         p = getpwnam("guest");
 182                 }
 183                 if (p) {
 184                         u = p->pw_uid;
 185                 }
 186                 if (u > 0) {
 187                         ctdluid = u;
 188                 }
 189         }
 190
 191         // initialize the master context
 192         InitializeMasterCC();
 193
 194         setlogmask(LOG_UPTO(max_log_level));
 195         openlog("citserver",
 196                 ( running_as_daemon ? (LOG_PID) : (LOG_PID | LOG_PERROR) ),
 197                 syslog_facility
 198         );
 199
 200         if ((mkdir(ctdl_run_dir, 0755) != 0) && (errno != EEXIST)) {
 201                 syslog(LOG_ERR, "main: unable to create run directory [%s]: %m", ctdl_run_dir);
 202         }
 203
 204         if (chown(ctdl_run_dir, ctdluid, (pwp==NULL)?-1:pw.pw_gid) != 0) {
 205                 syslog(LOG_ERR, "main: unable to set the access rights for [%s]: %m", ctdl_run_dir);
 206         }
 207
 208         ctdl_lockfile(1);
 209         init_sysdep();                                          // Initialize...
 210         master_startup();                                       // Do non system dependent startup functions
 211         check_control();                                        // Check/sanitize/initialize control record, fix user indexes
 212         syslog(LOG_INFO, "main: upgrading modules");            // Run any upgrade entry points
 213         pre_startup_upgrades();
 214
 215         // Setting this key to nonzero causes the server to regenerate all data that can be derived
 216         // from other tables: usersbynumber, directory, fulltext.
 217         // The import utility (ctdlload) sets this key.
 218         if (CtdlGetConfigInt("regenerate_secondary_indices") != 0) {
 219                 regenerate_secondary_indices();
 220         }
 221
 222
 223         // Load the user for the masterCC or create them if they don't exist
 224         if (CtdlGetUser(&masterCC.user, "SYS_Citadel")) {
 225                 // User doesn't exist. We can't use create user here as the user number needs to be 0
 226                 strcpy(masterCC.user.fullname, "SYS_Citadel") ;
 227                 CtdlPutUser(&masterCC.user);
 228                 CtdlGetUser(&masterCC.user, "SYS_Citadel");     // Just to be safe
 229         }
 230
 231         // Bind the server to a Unix-domain socket (user client access)
 232         CtdlRegisterServiceHook(0,
 233                                 file_citadel_socket,
 234                                 citproto_begin_session,
 235                                 do_command_loop,
 236                                 do_async_loop,
 237                                 CitadelServiceUDS);
 238
 239         // Bind the server to a Unix-domain socket (admin client access)
 240         CtdlRegisterServiceHook(0,
 241                                 file_citadel_admin_socket,
 242                                 citproto_begin_admin_session,
 243                                 do_command_loop,
 244                                 do_async_loop,
 245                                 CitadelServiceUDS);
 246         chmod(file_citadel_admin_socket, S_IRWXU);              // protect the admin socket - it offers high privilege
 247
 248         // Bind the server to our favorite TCP port (usually 504).
 249         CtdlRegisterServiceHook(CtdlGetConfigInt("c_port_number"),
 250                                 NULL,
 251                                 citproto_begin_session,
 252                                 do_command_loop,
 253                                 do_async_loop,
 254                                 CitadelServiceTCP);
 255
 256         // Load any server-side extensions available here.
 257         syslog(LOG_INFO, "main: initializing server extensions");
 258         initialize_modules(0);
 259
 260         // If we need host auth, start our chkpwd daemon.
 261         if (CtdlGetConfigInt("c_auth_mode") == AUTHMODE_HOST) {
 262                 start_chkpwd_daemon();
 263         }
 264
 265         // Now that we've bound the sockets, change to the Citadel user id and its corresponding group ids
 266         getpwuid_r(ctdluid, &pw, pwbuf, sizeof(pwbuf), &pwp);
 267         if (pwp == NULL) {
 268                 syslog(LOG_ERR, "main: WARNING, getpwuid(%ld): %m Group IDs will be incorrect.", (long)ctdluid);
 269         }
 270         else {
 271                 initgroups(pw.pw_name, pw.pw_gid);
 272                 if (setgid(pw.pw_gid)) {
 273                         syslog(LOG_ERR, "main: setgid(%ld): %m", (long)pw.pw_gid);
 274                 }
 275         }
 276         if (drop_root_perms) {
 277                 syslog(LOG_INFO, "main: changing uid to %ld", (long)ctdluid);
 278                 if (setuid(ctdluid) != 0) {
 279                         syslog(LOG_ERR, "main: setuid() failed: %m");
 280                 }
 281 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 282                 prctl(PR_SET_DUMPABLE, 1);
 283 #endif
 284         }
 285
 286         // We want to check for idle sessions once per minute
 287         CtdlRegisterSessionHook(terminate_idle_sessions, EVT_TIMER, PRIO_CLEANUP + 1);
 288
 289         // Are we in the undocumented rescue mode?
 290         if (rescue_string) {
 291                 undocumented_rescue_mode(rescue_string);
 292         }
 293         else {
 294                 // Go into multithreaded mode.  When this call exits, the server is stopping.
 295                 go_threading();
 296         }
 297
 298         // Get ready to shut down the server.
 299         master_cleanup(exit_signal);
 300 }