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