citadel/citserver.c

   1 /*
   2  * Main source module for the Citadel server
   3  *
   4  * Copyright (c) 1987-2011 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 as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20
  21 #include "sysdep.h"
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <stdio.h>
  25 #include <fcntl.h>
  26 #include <signal.h>
  27 #include <sys/types.h>
  28 #include <sys/stat.h>
  29
  30 #if TIME_WITH_SYS_TIME
  31 # include <sys/time.h>
  32 # include <time.h>
  33 #else
  34 # if HAVE_SYS_TIME_H
  35 #  include <sys/time.h>
  36 # else
  37 #  include <time.h>
  38 # endif
  39 #endif
  40
  41 #if HAVE_BACKTRACE
  42 #include <execinfo.h>
  43 #endif
  44
  45 #include <ctype.h>
  46 #include <string.h>
  47 #include <dirent.h>
  48 #include <errno.h>
  49 #include <limits.h>
  50 #include <netdb.h>
  51 #include <sys/types.h>
  52 #include <sys/socket.h>
  53 #include <netinet/in.h>
  54 #include <arpa/inet.h>
  55 #include <libcitadel.h>
  56 #include "citadel.h"
  57 #include "server.h"
  58 #include "sysdep_decls.h"
  59 #include "threads.h"
  60 #include "citserver.h"
  61 #include "config.h"
  62 #include "database.h"
  63 #include "housekeeping.h"
  64 #include "user_ops.h"
  65 #include "msgbase.h"
  66 #include "support.h"
  67 #include "locate_host.h"
  68 #include "room_ops.h"
  69 #include "file_ops.h"
  70 #include "control.h"
  71 #include "euidindex.h"
  72 #include "context.h"
  73 #include "svn_revision.h"
  74
  75 #ifndef HAVE_SNPRINTF
  76 #include "snprintf.h"
  77 #endif
  78
  79 #include "ctdl_module.h"
  80
  81 char *unique_session_numbers;
  82 int ScheduledShutdown = 0;
  83 time_t server_startup_time;
  84 int panic_fd;
  85 int openid_level_supported = 0;
  86
  87 /*
  88  * print the actual stack frame.
  89  */
  90 void cit_backtrace(void)
  91 {
  92 #ifdef HAVE_BACKTRACE
  93         void *stack_frames[50];
  94         size_t size, i;
  95         char **strings;
  96
  97
  98         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
  99         strings = backtrace_symbols(stack_frames, size);
 100         for (i = 0; i < size; i++) {
 101                 if (strings != NULL)
 102                         syslog(LOG_ALERT, "%s\n", strings[i]);
 103                 else
 104                         syslog(LOG_ALERT, "%p\n", stack_frames[i]);
 105         }
 106         free(strings);
 107 #endif
 108 }
 109
 110 /*
 111  * print the actual stack frame.
 112  */
 113 void cit_panic_backtrace(int SigNum)
 114 {
 115 #ifdef HAVE_BACKTRACE
 116         void *stack_frames[10];
 117         size_t size, i;
 118         char **strings;
 119
 120         printf("caught signal 11\n");
 121         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 122         strings = backtrace_symbols(stack_frames, size);
 123         for (i = 0; i < size; i++) {
 124                 if (strings != NULL)
 125                         syslog(LOG_ALERT, "%s\n", strings[i]);
 126                 else
 127                         syslog(LOG_ALERT, "%p\n", stack_frames[i]);
 128         }
 129         free(strings);
 130 #endif
 131         exit(-1);
 132 }
 133
 134 /*
 135  * Various things that need to be initialized at startup
 136  */
 137 void master_startup(void) {
 138         struct timeval tv;
 139         unsigned int seed;
 140         FILE *urandom;
 141         struct ctdlroom qrbuf;
 142         int rv;
 143
 144         syslog(LOG_DEBUG, "master_startup() started\n");
 145         time(&server_startup_time);
 146
 147         syslog(LOG_INFO, "Opening databases\n");
 148         open_databases();
 149         check_ref_counts();
 150
 151         syslog(LOG_INFO, "Creating base rooms (if necessary)\n");
 152         CtdlCreateRoom(config.c_baseroom,       0, "", 0, 1, 0, VIEW_BBS);
 153         CtdlCreateRoom(AIDEROOM,                3, "", 0, 1, 0, VIEW_BBS);
 154         CtdlCreateRoom(SYSCONFIGROOM,           3, "", 0, 1, 0, VIEW_BBS);
 155         CtdlCreateRoom(config.c_twitroom,       0, "", 0, 1, 0, VIEW_BBS);
 156
 157         /* The "Local System Configuration" room doesn't need to be visible */
 158         if (CtdlGetRoomLock(&qrbuf, SYSCONFIGROOM) == 0) {
 159                 qrbuf.QRflags2 |= QR2_SYSTEM;
 160                 CtdlPutRoomLock(&qrbuf);
 161         }
 162
 163         /* Aide needs to be public postable, else we're not RFC conformant. */
 164         if (CtdlGetRoomLock(&qrbuf, AIDEROOM) == 0) {
 165                 qrbuf.QRflags2 |= QR2_SMTP_PUBLIC;
 166                 CtdlPutRoomLock(&qrbuf);
 167         }
 168
 169         syslog(LOG_INFO, "Seeding the pseudo-random number generator...\n");
 170         urandom = fopen("/dev/urandom", "r");
 171         if (urandom != NULL) {
 172                 rv = fread(&seed, sizeof seed, 1, urandom);
 173                 fclose(urandom);
 174         }
 175         else {
 176                 gettimeofday(&tv, NULL);
 177                 seed = tv.tv_usec;
 178         }
 179         srand(seed);
 180         srandom(seed);
 181
 182         syslog(LOG_INFO, "Initializing ipgm secret\n");
 183         get_config();
 184         config.c_ipgm_secret = rand();
 185         put_config();
 186
 187         syslog(LOG_DEBUG, "master_startup() finished\n");
 188 }
 189
 190
 191 /*
 192  * Cleanup routine to be called when the server is shutting down.
 193  */
 194 void master_cleanup(int exitcode) {
 195         struct CleanupFunctionHook *fcn;
 196         static int already_cleaning_up = 0;
 197
 198         if (already_cleaning_up) while(1) sleep(1);
 199         already_cleaning_up = 1;
 200
 201         /* Run any cleanup routines registered by loadable modules */
 202         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 203                 (*fcn->h_function_pointer)();
 204         }
 205
 206         /* Close the AdjRefCount queue file */
 207         AdjRefCount(-1, 0);
 208
 209         /* Do system-dependent stuff */
 210         sysdep_master_cleanup();
 211
 212         /* Close databases */
 213         syslog(LOG_INFO, "Closing databases\n");
 214         close_databases();
 215
 216         /* If the operator requested a halt but not an exit, halt here. */
 217         if (shutdown_and_halt) {
 218                 syslog(LOG_NOTICE, "citserver: Halting server without exiting.\n");
 219                 fflush(stdout); fflush(stderr);
 220                 while(1) {
 221                         sleep(32767);
 222                 }
 223         }
 224
 225         release_control();
 226
 227         /* Now go away. */
 228         syslog(LOG_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 229         fflush(stdout); fflush(stderr);
 230
 231         if (restart_server != 0)
 232                 exit(1);
 233         if ((running_as_daemon != 0) && ((exitcode == 0) ))
 234                 exitcode = CTDLEXIT_SHUTDOWN;
 235         exit(exitcode);
 236 }
 237
 238
 239
 240 /*
 241  * cmd_info()  -  tell the client about this server
 242  */
 243 void cmd_info(char *cmdbuf) {
 244         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 245         cprintf("%d\n", CC->cs_pid);
 246         cprintf("%s\n", config.c_nodename);
 247         cprintf("%s\n", config.c_humannode);
 248         cprintf("%s\n", config.c_fqdn);
 249         cprintf("%s\n", CITADEL);
 250         cprintf("%d\n", REV_LEVEL);
 251         cprintf("%s\n", config.c_site_location);
 252         cprintf("%s\n", config.c_sysadm);
 253         cprintf("%d\n", SERVER_TYPE);
 254         cprintf("%s\n", config.c_moreprompt);
 255         cprintf("1\n"); /* 1 = yes, this system supports floors */
 256         cprintf("1\n"); /* 1 = we support the extended paging options */
 257         cprintf("\n");  /* nonce no longer supported */
 258         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 259
 260 #ifdef HAVE_LDAP
 261         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
 262 #else
 263         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
 264 #endif
 265
 266         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 267                 cprintf("%d\n", config.c_disable_newu);
 268         }
 269         else {
 270                 cprintf("1\n"); /* "create new user" does not work with non-native auth modes */
 271         }
 272
 273         cprintf("%s\n", config.c_default_cal_zone);
 274
 275         /* thread load averages -- temporarily disabled during refactoring of this code */
 276         cprintf("0\n");         /* load average */
 277         cprintf("0\n");         /* worker average */
 278         cprintf("0\n");         /* thread count */
 279
 280         cprintf("1\n");         /* yes, Sieve mail filtering is supported */
 281         cprintf("%d\n", config.c_enable_fulltext);
 282         cprintf("%s\n", svn_revision());
 283
 284         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 285                 cprintf("%d\n", openid_level_supported); /* OpenID is enabled when using native auth */
 286         }
 287         else {
 288                 cprintf("0\n"); /* OpenID is disabled when using non-native auth */
 289         }
 290
 291         cprintf("%d\n", config.c_guest_logins);
 292
 293         cprintf("000\n");
 294 }
 295
 296
 297 /*
 298  * returns an asterisk if there are any instant messages waiting,
 299  * space otherwise.
 300  */
 301 char CtdlCheckExpress(void) {
 302         if (CC->FirstExpressMessage == NULL) {
 303                 return(' ');
 304         }
 305         else {
 306                 return('*');
 307         }
 308 }
 309
 310 void cmd_time(char *argbuf)
 311 {
 312    time_t tv;
 313    struct tm tmp;
 314
 315    tv = time(NULL);
 316    localtime_r(&tv, &tmp);
 317
 318    /* timezone and daylight global variables are not portable. */
 319 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 320    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst);
 321 #else
 322    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst);
 323 #endif
 324 }
 325
 326
 327 /*
 328  * Check originating host against the public_clients file.  This determines
 329  * whether the client is allowed to change the hostname for this session
 330  * (for example, to show the location of the user rather than the location
 331  * of the client).
 332  */
 333 int is_public_client(void)
 334 {
 335         char buf[1024];
 336         char addrbuf[1024];
 337         FILE *fp;
 338         int i;
 339         char *public_clientspos;
 340         char *public_clientsend;
 341         char *paddr = NULL;
 342         struct stat statbuf;
 343         static time_t pc_timestamp = 0;
 344         static char public_clients[SIZ];
 345         static char public_clients_file[SIZ];
 346
 347 #define LOCALHOSTSTR "127.0.0.1"
 348
 349         snprintf(public_clients_file, sizeof public_clients_file, "%s/public_clients", ctdl_etc_dir);
 350
 351         /*
 352          * Check the time stamp on the public_clients file.  If it's been
 353          * updated since the last time we were here (or if this is the first
 354          * time we've been through the loop), read its contents and learn
 355          * the IP addresses of the listed hosts.
 356          */
 357         if (stat(public_clients_file, &statbuf) != 0) {
 358                 /* No public_clients file exists, so bail out */
 359                 syslog(LOG_WARNING, "Warning: '%s' does not exist\n",
 360                                 public_clients_file);
 361                 return(0);
 362         }
 363
 364         if (statbuf.st_mtime > pc_timestamp) {
 365                 begin_critical_section(S_PUBLIC_CLIENTS);
 366                 syslog(LOG_INFO, "Loading %s\n", public_clients_file);
 367
 368                 public_clientspos = &public_clients[0];
 369                 public_clientsend = public_clientspos + SIZ;
 370                 safestrncpy(public_clientspos, LOCALHOSTSTR, sizeof public_clients);
 371                 public_clientspos += sizeof(LOCALHOSTSTR) - 1;
 372
 373                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 374                         *(public_clientspos++) = '|';
 375                         paddr = &addrbuf[0];
 376                         while (!IsEmptyStr (paddr) &&
 377                                (public_clientspos < public_clientsend))
 378                                 *(public_clientspos++) = *(paddr++);
 379                 }
 380
 381                 fp = fopen(public_clients_file, "r");
 382                 if (fp != NULL)
 383                         while ((fgets(buf, sizeof buf, fp)!=NULL) &&
 384                                (public_clientspos < public_clientsend)){
 385                                 char *ptr;
 386                                 ptr = buf;
 387                                 while (!IsEmptyStr(ptr)) {
 388                                         if (*ptr == '#') {
 389                                                 *ptr = 0;
 390                                                 break;
 391                                         }
 392                                 else ptr++;
 393                                 }
 394                                 ptr--;
 395                                 while (ptr>buf && isspace(*ptr)) {
 396                                         *(ptr--) = 0;
 397                                 }
 398                                 if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 399                                         *(public_clientspos++) = '|';
 400                                         paddr = addrbuf;
 401                                         while (!IsEmptyStr(paddr) &&
 402                                                (public_clientspos < public_clientsend)){
 403                                                 *(public_clientspos++) = *(paddr++);
 404                                         }
 405                                 }
 406                         }
 407                 fclose(fp);
 408                 pc_timestamp = time(NULL);
 409                 end_critical_section(S_PUBLIC_CLIENTS);
 410         }
 411
 412         syslog(LOG_DEBUG, "Checking whether %s is a local or public client\n",
 413                 CC->cs_addr);
 414         for (i=0; i<num_parms(public_clients); ++i) {
 415                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 416                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 417                         syslog(LOG_DEBUG, "... yes its local.\n");
 418                         return(1);
 419                 }
 420         }
 421
 422         /* No hits.  This is not a public client. */
 423         syslog(LOG_DEBUG, "... no it isn't.\n");
 424         return(0);
 425 }
 426
 427
 428 /*
 429  * the client is identifying itself to the server
 430  */
 431 void cmd_iden(char *argbuf)
 432 {
 433         int dev_code;
 434         int cli_code;
 435         int rev_level;
 436         char desc[128];
 437         char from_host[128];
 438
 439         if (num_parms(argbuf)<4) {
 440                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
 441                 return;
 442         }
 443
 444         dev_code = extract_int(argbuf,0);
 445         cli_code = extract_int(argbuf,1);
 446         rev_level = extract_int(argbuf,2);
 447         extract_token(desc, argbuf, 3, '|', sizeof desc);
 448
 449         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 450         from_host[sizeof from_host - 1] = 0;
 451         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
 452
 453         CC->cs_clientdev = dev_code;
 454         CC->cs_clienttyp = cli_code;
 455         CC->cs_clientver = rev_level;
 456         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 457         CC->cs_clientname[31] = 0;
 458
 459         /* For local sockets and public clients, trust the hostname supplied by the client */
 460         if ( (CC->is_local_socket) || (is_public_client()) ) {
 461                 safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 462                 CC->cs_host[sizeof CC->cs_host - 1] = 0;
 463                 CC->cs_addr[0] = 0;
 464         }
 465
 466         syslog(LOG_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
 467                 dev_code,
 468                 cli_code,
 469                 (rev_level / 100),
 470                 (rev_level % 100),
 471                 desc,
 472                 CC->cs_host
 473         );
 474         cprintf("%d Ok\n",CIT_OK);
 475 }
 476
 477
 478 /*
 479  * display system messages or help
 480  */
 481 void cmd_mesg(char *mname)
 482 {
 483         FILE *mfp;
 484         char targ[256];
 485         char buf[256];
 486         char buf2[256];
 487         char *dirs[2];
 488         DIR *dp;
 489         struct dirent *d;
 490
 491         extract_token(buf, mname, 0, '|', sizeof buf);
 492
 493         dirs[0] = strdup(ctdl_message_dir);
 494         dirs[1] = strdup(ctdl_hlp_dir);
 495
 496         snprintf(buf2, sizeof buf2, "%s.%d.%d",
 497                 buf, CC->cs_clientdev, CC->cs_clienttyp);
 498
 499         /* If the client requested "?" then produce a listing */
 500         if (!strcmp(buf, "?")) {
 501                 cprintf("%d %s\n", LISTING_FOLLOWS, buf);
 502                 dp = opendir(dirs[1]);
 503                 if (dp != NULL) {
 504                         while (d = readdir(dp), d != NULL) {
 505                                 if (d->d_name[0] != '.') {
 506                                         cprintf(" %s\n", d->d_name);
 507                                 }
 508                         }
 509                         closedir(dp);
 510                 }
 511                 cprintf("000\n");
 512                 free(dirs[0]);
 513                 free(dirs[1]);
 514                 return;
 515         }
 516
 517         /* Otherwise, look for the requested file by name. */
 518         else {
 519                 mesg_locate(targ, sizeof targ, buf2, 2, (const char **)dirs);
 520                 if (IsEmptyStr(targ)) {
 521                         snprintf(buf2, sizeof buf2, "%s.%d",
 522                                                         buf, CC->cs_clientdev);
 523                         mesg_locate(targ, sizeof targ, buf2, 2,
 524                                                         (const char **)dirs);
 525                         if (IsEmptyStr(targ)) {
 526                                 mesg_locate(targ, sizeof targ, buf, 2,
 527                                                         (const char **)dirs);
 528                         }
 529                 }
 530         }
 531
 532         free(dirs[0]);
 533         free(dirs[1]);
 534
 535         if (IsEmptyStr(targ)) {
 536                 cprintf("%d '%s' not found.  (Searching in %s and %s)\n",
 537                         ERROR + FILE_NOT_FOUND,
 538                         mname,
 539                         ctdl_message_dir,
 540                         ctdl_hlp_dir
 541                 );
 542                 return;
 543         }
 544
 545         mfp = fopen(targ, "r");
 546         if (mfp==NULL) {
 547                 cprintf("%d Cannot open '%s': %s\n",
 548                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 549                 return;
 550         }
 551         cprintf("%d %s\n", LISTING_FOLLOWS,buf);
 552
 553         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
 554                 buf[strlen(buf)-1] = 0;
 555                 do_help_subst(buf);
 556                 cprintf("%s\n",buf);
 557         }
 558
 559         fclose(mfp);
 560         cprintf("000\n");
 561 }
 562
 563
 564 /*
 565  * enter system messages or help
 566  */
 567 void cmd_emsg(char *mname)
 568 {
 569         FILE *mfp;
 570         char targ[256];
 571         char buf[256];
 572         char *dirs[2];
 573         int a;
 574
 575         unbuffer_output();
 576
 577         if (CtdlAccessCheck(ac_aide)) return;
 578
 579         extract_token(buf, mname, 0, '|', sizeof buf);
 580         for (a=0; !IsEmptyStr(&buf[a]); ++a) {          /* security measure */
 581                 if (buf[a] == '/') buf[a] = '.';
 582         }
 583
 584         dirs[0] = strdup(ctdl_message_dir);
 585         dirs[1] = strdup(ctdl_hlp_dir);
 586
 587         mesg_locate(targ, sizeof targ, buf, 2, (const char**)dirs);
 588         free(dirs[0]);
 589         free(dirs[1]);
 590
 591         if (IsEmptyStr(targ)) {
 592                 snprintf(targ, sizeof targ,
 593                                  "%s/%s",
 594                                  ctdl_hlp_dir, buf);
 595         }
 596
 597         mfp = fopen(targ,"w");
 598         if (mfp==NULL) {
 599                 cprintf("%d Cannot open '%s': %s\n",
 600                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 601                 return;
 602         }
 603         cprintf("%d %s\n", SEND_LISTING, targ);
 604
 605         while (client_getln(buf, sizeof buf) >=0 && strcmp(buf, "000")) {
 606                 fprintf(mfp, "%s\n", buf);
 607         }
 608
 609         fclose(mfp);
 610 }
 611
 612
 613 /* Don't show the names of private rooms unless the viewing
 614  * user also knows the rooms.
 615  */
 616 void GenerateRoomDisplay(char *real_room,
 617                         CitContext *viewed,
 618                         CitContext *viewer) {
 619
 620         int ra;
 621
 622         strcpy(real_room, viewed->room.QRname);
 623         if (viewed->room.QRflags & QR_MAILBOX) {
 624                 strcpy(real_room, &real_room[11]);
 625         }
 626         if (viewed->room.QRflags & QR_PRIVATE) {
 627                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
 628                 if ( (ra & UA_KNOWN) == 0) {
 629                         strcpy(real_room, " ");
 630                 }
 631         }
 632
 633         if (viewed->cs_flags & CS_CHAT) {
 634                 while (strlen(real_room) < 14) {
 635                         strcat(real_room, " ");
 636                 }
 637                 strcpy(&real_room[14], "<chat>");
 638         }
 639
 640 }
 641
 642 /*
 643  * Convenience function.
 644  */
 645 int CtdlAccessCheck(int required_level) {
 646
 647         if (CC->internal_pgm) return(0);
 648         if (required_level >= ac_internal) {
 649                 cprintf("%d This is not a user-level command.\n",
 650                         ERROR + HIGHER_ACCESS_REQUIRED);
 651                 return(-1);
 652         }
 653
 654         if ((required_level >= ac_logged_in_or_guest) && (CC->logged_in == 0) && (!config.c_guest_logins)) {
 655                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 656                 return(-1);
 657         }
 658
 659         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
 660                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 661                 return(-1);
 662         }
 663
 664         if (CC->user.axlevel >= AxAideU) return(0);
 665         if (required_level >= ac_aide) {
 666                 cprintf("%d This command requires Aide access.\n",
 667                         ERROR + HIGHER_ACCESS_REQUIRED);
 668                 return(-1);
 669         }
 670
 671         if (is_room_aide()) return(0);
 672         if (required_level >= ac_room_aide) {
 673                 cprintf("%d This command requires Aide or Room Aide access.\n",
 674                         ERROR + HIGHER_ACCESS_REQUIRED);
 675                 return(-1);
 676         }
 677
 678         /* shhh ... succeed quietly */
 679         return(0);
 680 }
 681
 682
 683
 684 /*
 685  * Terminate another running session
 686  */
 687 void cmd_term(char *cmdbuf)
 688 {
 689         int session_num;
 690         int terminated = 0;
 691
 692         session_num = extract_int(cmdbuf, 0);
 693
 694         terminated = CtdlTerminateOtherSession(session_num);
 695
 696         if (terminated < 0) {
 697                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
 698                 return;
 699         }
 700
 701         if (terminated & TERM_FOUND) {
 702                 if (terminated == TERM_KILLED) {
 703                         cprintf("%d Session terminated.\n", CIT_OK);
 704                 }
 705                 else {
 706                         cprintf("%d You are not allowed to do that.\n",
 707                                 ERROR + HIGHER_ACCESS_REQUIRED);
 708                 }
 709         }
 710         else {
 711                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
 712         }
 713 }
 714
 715
 716 /*
 717  * get the paginator prompt
 718  */
 719 void cmd_more(char *argbuf) {
 720         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 721 }
 722
 723
 724 /*
 725  * echo
 726  */
 727 void cmd_echo(char *etext)
 728 {
 729         cprintf("%d %s\n", CIT_OK, etext);
 730 }
 731
 732
 733 /*
 734  * Perform privilege escalation for an internal program
 735  */
 736 void cmd_ipgm(char *argbuf)
 737 {
 738         int secret;
 739
 740         secret = extract_int(argbuf, 0);
 741
 742         /* For security reasons, we do NOT allow this command to run
 743          * over the network.  Local sockets only.
 744          */
 745         if (!CC->is_local_socket) {
 746                 sleep(5);
 747                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 748         }
 749         else if (secret == config.c_ipgm_secret) {
 750                 CC->internal_pgm = 1;
 751                 strcpy(CC->curr_user, "<internal program>");
 752                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 753                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
 754         }
 755         else {
 756                 sleep(5);
 757                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 758                 syslog(LOG_ERR, "Warning: ipgm authentication failed.\n");
 759                 CC->kill_me = KILLME_AUTHFAILED;
 760         }
 761 }
 762
 763
 764 /*
 765  * Shut down the server
 766  */
 767 void cmd_down(char *argbuf) {
 768         char *Reply ="%d Shutting down server.  Goodbye.\n";
 769
 770         if (CtdlAccessCheck(ac_aide)) return;
 771
 772         if (!IsEmptyStr(argbuf))
 773         {
 774                 int state = CIT_OK;
 775                 restart_server = extract_int(argbuf, 0);
 776
 777                 if (restart_server > 0)
 778                 {
 779                         Reply = "%d citserver will now shut down and automatically restart.\n";
 780                 }
 781                 if ((restart_server > 0) && !running_as_daemon)
 782                 {
 783                         syslog(LOG_ERR, "The user requested restart, but not running as daemon! Geronimooooooo!\n");
 784                         Reply = "%d Warning: citserver is not running in daemon mode and is therefore unlikely to restart automatically.\n";
 785                         state = ERROR;
 786                 }
 787                 cprintf(Reply, state);
 788         }
 789         else
 790         {
 791                 cprintf(Reply, CIT_OK + SERVER_SHUTTING_DOWN);
 792         }
 793         CC->kill_me = KILLME_SERVER_SHUTTING_DOWN;
 794         server_shutting_down = 1;
 795 }
 796
 797
 798 /*
 799  * Halt the server without exiting the server process.
 800  */
 801 void cmd_halt(char *argbuf) {
 802
 803         if (CtdlAccessCheck(ac_aide)) return;
 804
 805         cprintf("%d Halting server.  Goodbye.\n", CIT_OK);
 806         server_shutting_down = 1;
 807         shutdown_and_halt = 1;
 808 }
 809
 810
 811 /*
 812  * Schedule or cancel a server shutdown
 813  */
 814 void cmd_scdn(char *argbuf)
 815 {
 816         int new_state;
 817         int state = CIT_OK;
 818         char *Reply = "%d %d\n";
 819
 820         if (CtdlAccessCheck(ac_aide)) return;
 821
 822         new_state = extract_int(argbuf, 0);
 823         if ((new_state == 2) || (new_state == 3))
 824         {
 825                 restart_server = 1;
 826                 if (!running_as_daemon)
 827                 {
 828                         syslog(LOG_ERR, "The user requested restart, but not running as deamon! Geronimooooooo!\n");
 829                         Reply = "%d %d Warning, not running in deamon mode. maybe we will come up again, but don't lean on it.\n";
 830                         state = ERROR;
 831                 }
 832
 833                 restart_server = extract_int(argbuf, 0);
 834                 new_state -= 2;
 835         }
 836         if ((new_state == 0) || (new_state == 1)) {
 837                 ScheduledShutdown = new_state;
 838         }
 839         cprintf(Reply, state, ScheduledShutdown);
 840 }
 841
 842
 843 /*
 844  * Set or unset asynchronous protocol mode
 845  */
 846 void cmd_asyn(char *argbuf)
 847 {
 848         int new_state;
 849
 850         new_state = extract_int(argbuf, 0);
 851         if ((new_state == 0) || (new_state == 1)) {
 852                 CC->is_async = new_state;
 853         }
 854         cprintf("%d %d\n", CIT_OK, CC->is_async);
 855 }
 856
 857
 858
 859 /*
 860  * Back-end function for starting a session
 861  */
 862 void begin_session(CitContext *con)
 863 {
 864         socklen_t len;
 865         struct sockaddr_in sin;
 866
 867         /*
 868          * Initialize some variables specific to our context.
 869          */
 870         con->logged_in = 0;
 871         con->internal_pgm = 0;
 872         con->download_fp = NULL;
 873         con->upload_fp = NULL;
 874         con->cached_msglist = NULL;
 875         con->cached_num_msgs = 0;
 876         con->FirstExpressMessage = NULL;
 877         time(&con->lastcmd);
 878         time(&con->lastidle);
 879         strcpy(con->lastcmdname, "    ");
 880         strcpy(con->cs_clientname, "(unknown)");
 881         strcpy(con->curr_user, NLI);
 882         *con->net_node = '\0';
 883         *con->fake_username = '\0';
 884         *con->fake_hostname = '\0';
 885         *con->fake_roomname = '\0';
 886         *con->cs_clientinfo = '\0';
 887         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 888         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 889         con->cs_UDSclientUID = -1;
 890         con->cs_host[sizeof con->cs_host - 1] = 0;
 891         len = sizeof sin;
 892         if (!CC->is_local_socket) {
 893                 locate_host(con->cs_host, sizeof con->cs_host,
 894                         con->cs_addr, sizeof con->cs_addr,
 895                         con->client_socket
 896                 );
 897         }
 898         else {
 899                 con->cs_host[0] = 0;
 900                 con->cs_addr[0] = 0;
 901 #ifdef HAVE_STRUCT_UCRED
 902                 {
 903                         /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
 904                         struct ucred credentials;
 905                         socklen_t ucred_length = sizeof(struct ucred);
 906
 907                         /*fill in the user data structure */
 908                         if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
 909                                 syslog(LOG_NOTICE, "could obtain credentials from unix domain socket");
 910
 911                         }
 912                         else {
 913                                 /* the process ID of the process on the other side of the socket */
 914                                 /* credentials.pid; */
 915
 916                                 /* the effective UID of the process on the other side of the socket  */
 917                                 con->cs_UDSclientUID = credentials.uid;
 918
 919                                 /* the effective primary GID of the process on the other side of the socket */
 920                                 /* credentials.gid; */
 921
 922                                 /* To get supplemental groups, we will have to look them up in our account
 923                                    database, after a reverse lookup on the UID to get the account name.
 924                                    We can take this opportunity to check to see if this is a legit account.
 925                                 */
 926                                 snprintf(con->cs_clientinfo, sizeof(con->cs_clientinfo),
 927                                          "PID: "F_PID_T"; UID: "F_UID_T"; GID: "F_XPID_T" ",
 928                                          credentials.pid,
 929                                          credentials.uid,
 930                                          credentials.gid);
 931                         }
 932                 }
 933 #endif
 934         }
 935         con->cs_flags = 0;
 936         con->upload_type = UPL_FILE;
 937         con->dl_is_net = 0;
 938
 939         con->nologin = 0;
 940         if (((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions)) || CtdlWantSingleUser()) {
 941                 con->nologin = 1;
 942         }
 943
 944         if (!CC->is_local_socket) {
 945                 syslog(LOG_NOTICE, "Session (%s) started from %s (%s).\n", con->ServiceName, con->cs_host, con->cs_addr);
 946         }
 947         else {
 948                 syslog(LOG_NOTICE, "Session (%s) started via local socket UID:%d.\n", con->ServiceName, con->cs_UDSclientUID);
 949         }
 950
 951         /* Run any session startup routines registered by loadable modules */
 952         PerformSessionHooks(EVT_START);
 953 }
 954
 955
 956 void citproto_begin_session() {
 957         if (CC->nologin==1) {
 958                 cprintf("%d %s: Too many users are already online (maximum is %d)\n",
 959                         ERROR + MAX_SESSIONS_EXCEEDED,
 960                         config.c_nodename, config.c_maxsessions
 961                 );
 962                 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
 963         }
 964         else {
 965                 cprintf("%d %s Citadel server ready.\n", CIT_OK, config.c_nodename);
 966                 CC->can_receive_im = 1;
 967         }
 968 }
 969
 970
 971 void cmd_noop(char *argbuf)
 972 {
 973         cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
 974 }
 975
 976
 977 void cmd_qnop(char *argbuf)
 978 {
 979         /* do nothing, this command returns no response */
 980 }
 981
 982
 983 void cmd_quit(char *argbuf)
 984 {
 985         cprintf("%d Goodbye.\n", CIT_OK);
 986         CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
 987 }
 988
 989
 990 void cmd_lout(char *argbuf)
 991 {
 992         if (CC->logged_in)
 993                 CtdlUserLogout();
 994         cprintf("%d logged out.\n", CIT_OK);
 995 }
 996
 997
 998 /*
 999  * This loop recognizes all server commands.
1000  */
1001 void do_command_loop(void) {
1002         char cmdbuf[SIZ];
1003
1004         time(&CC->lastcmd);
1005         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
1006         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
1007                 syslog(LOG_ERR, "Citadel client disconnected: ending session.\n");
1008                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1009                 return;
1010         }
1011
1012         /* Log the server command, but don't show passwords... */
1013         if ( (strncasecmp(cmdbuf, "PASS", 4)) && (strncasecmp(cmdbuf, "SETP", 4)) ) {
1014                 syslog(LOG_INFO, "[%d][%s(%ld)] %s",
1015                         CC->cs_pid, CC->curr_user, CC->user.usernum, cmdbuf
1016                 );
1017         }
1018         else {
1019                 syslog(LOG_INFO, "[%d][%s(%ld)] <password command hidden from log>",
1020                         CC->cs_pid, CC->curr_user, CC->user.usernum
1021                 );
1022         }
1023
1024         buffer_output();
1025
1026         /*
1027          * Let other clients see the last command we executed, and
1028          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
1029          */
1030         if ( (strncasecmp(cmdbuf, "NOOP", 4))
1031            && (strncasecmp(cmdbuf, "QNOP", 4))
1032            && (strncasecmp(cmdbuf, "PEXP", 4))
1033            && (strncasecmp(cmdbuf, "GEXP", 4))
1034            && (strncasecmp(cmdbuf, "RWHO", 4))
1035            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
1036                 strcpy(CC->lastcmdname, "    ");
1037                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
1038                 time(&CC->lastidle);
1039         }
1040
1041         if ((strncasecmp(cmdbuf, "ENT0", 4))
1042            && (strncasecmp(cmdbuf, "MESG", 4))
1043            && (strncasecmp(cmdbuf, "MSGS", 4)))
1044         {
1045            CC->cs_flags &= ~CS_POSTING;
1046         }
1047
1048         if (!DLoader_Exec_Cmd(cmdbuf)) {
1049                 cprintf("%d Unrecognized or unsupported command.\n", ERROR + CMD_NOT_SUPPORTED);
1050         }
1051
1052         unbuffer_output();
1053
1054         /* Run any after-each-command routines registered by modules */
1055         PerformSessionHooks(EVT_CMD);
1056 }
1057
1058
1059 /*
1060  * This loop performs all asynchronous functions.
1061  */
1062 void do_async_loop(void) {
1063         PerformSessionHooks(EVT_ASYNC);
1064 }
1065
1066
1067 /*****************************************************************************/
1068 /*                      MODULE INITIALIZATION STUFF                          */
1069 /*****************************************************************************/
1070
1071 CTDL_MODULE_INIT(citserver)
1072 {
1073         if (!threading) {
1074                 CtdlRegisterProtoHook(cmd_noop, "NOOP", "no operation");
1075                 CtdlRegisterProtoHook(cmd_qnop, "QNOP", "no operation with no response");
1076                 CtdlRegisterProtoHook(cmd_quit, "QUIT", "log out and disconnect from server");
1077                 CtdlRegisterProtoHook(cmd_lout, "LOUT", "log out but do not disconnect from server");
1078                 CtdlRegisterProtoHook(cmd_asyn, "ASYN", "enable asynchronous server responses");
1079                 CtdlRegisterProtoHook(cmd_info, "INFO", "fetch server capabilities and configuration");
1080                 CtdlRegisterProtoHook(cmd_mesg, "MESG", "fetch system banners");
1081                 CtdlRegisterProtoHook(cmd_emsg, "EMSG", "submit system banners");
1082                 CtdlRegisterProtoHook(cmd_echo, "ECHO", "echo text back to the client");
1083                 CtdlRegisterProtoHook(cmd_more, "MORE", "fetch the paginator prompt");
1084                 CtdlRegisterProtoHook(cmd_iden, "IDEN", "identify the client software and location");
1085                 CtdlRegisterProtoHook(cmd_ipgm, "IPGM", "perform privilege escalation for internal programs");
1086                 CtdlRegisterProtoHook(cmd_term, "TERM", "terminate another running session");
1087                 CtdlRegisterProtoHook(cmd_down, "DOWN", "perform a server shutdown");
1088                 CtdlRegisterProtoHook(cmd_halt, "HALT", "halt the server without exiting the server process");
1089                 CtdlRegisterProtoHook(cmd_scdn, "SCDN", "schedule or cancel a server shutdown");
1090                 CtdlRegisterProtoHook(cmd_time, "TIME", "fetch the date and time from the server");
1091         }
1092         /* return our id for the Log */
1093         return "citserver";
1094 }