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
 150         ctdl_thread_internal_init_tsd();
 151
 152         CtdlThreadAllocTSD();
 153
 154         check_ref_counts();
 155
 156         syslog(LOG_INFO, "Creating base rooms (if necessary)\n");
 157         CtdlCreateRoom(config.c_baseroom,       0, "", 0, 1, 0, VIEW_BBS);
 158         CtdlCreateRoom(AIDEROOM,                3, "", 0, 1, 0, VIEW_BBS);
 159         CtdlCreateRoom(SYSCONFIGROOM,           3, "", 0, 1, 0, VIEW_BBS);
 160         CtdlCreateRoom(config.c_twitroom,       0, "", 0, 1, 0, VIEW_BBS);
 161
 162         /* The "Local System Configuration" room doesn't need to be visible */
 163         if (CtdlGetRoomLock(&qrbuf, SYSCONFIGROOM) == 0) {
 164                 qrbuf.QRflags2 |= QR2_SYSTEM;
 165                 CtdlPutRoomLock(&qrbuf);
 166         }
 167
 168         /* Aide needs to be public postable, else we're not RFC conformant. */
 169         if (CtdlGetRoomLock(&qrbuf, AIDEROOM) == 0) {
 170                 qrbuf.QRflags2 |= QR2_SMTP_PUBLIC;
 171                 CtdlPutRoomLock(&qrbuf);
 172         }
 173
 174         syslog(LOG_INFO, "Seeding the pseudo-random number generator...\n");
 175         urandom = fopen("/dev/urandom", "r");
 176         if (urandom != NULL) {
 177                 rv = fread(&seed, sizeof seed, 1, urandom);
 178                 fclose(urandom);
 179         }
 180         else {
 181                 gettimeofday(&tv, NULL);
 182                 seed = tv.tv_usec;
 183         }
 184         srand(seed);
 185         srandom(seed);
 186
 187         syslog(LOG_INFO, "Initializing ipgm secret\n");
 188         get_config();
 189         config.c_ipgm_secret = rand();
 190         put_config();
 191
 192         syslog(LOG_DEBUG, "master_startup() finished\n");
 193 }
 194
 195
 196 /*
 197  * Cleanup routine to be called when the server is shutting down.
 198  */
 199 void master_cleanup(int exitcode) {
 200         struct CleanupFunctionHook *fcn;
 201         static int already_cleaning_up = 0;
 202
 203         if (already_cleaning_up) while(1) sleep(1);
 204         already_cleaning_up = 1;
 205
 206         /* Run any cleanup routines registered by loadable modules */
 207         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 208                 (*fcn->h_function_pointer)();
 209         }
 210
 211         /* Close the AdjRefCount queue file */
 212         AdjRefCount(-1, 0);
 213
 214         /* Do system-dependent stuff */
 215         sysdep_master_cleanup();
 216
 217         /* Close databases */
 218         syslog(LOG_INFO, "Closing databases\n");
 219         close_databases();
 220
 221 #ifdef DEBUG_MEMORY_LEAKS
 222         dump_heap();
 223 #endif
 224
 225         /* If the operator requested a halt but not an exit, halt here. */
 226         if (shutdown_and_halt) {
 227                 syslog(LOG_NOTICE, "citserver: Halting server without exiting.\n");
 228                 fflush(stdout); fflush(stderr);
 229                 while(1) {
 230                         sleep(32767);
 231                 }
 232         }
 233
 234         release_control();
 235
 236         /* Now go away. */
 237         syslog(LOG_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 238         fflush(stdout); fflush(stderr);
 239
 240         if (restart_server != 0)
 241                 exit(1);
 242         if ((running_as_daemon != 0) && ((exitcode == 0) ))
 243                 exitcode = CTDLEXIT_SHUTDOWN;
 244         exit(exitcode);
 245 }
 246
 247
 248
 249 /*
 250  * cmd_info()  -  tell the client about this server
 251  */
 252 void cmd_info(char *cmdbuf) {
 253         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 254         cprintf("%d\n", CC->cs_pid);
 255         cprintf("%s\n", config.c_nodename);
 256         cprintf("%s\n", config.c_humannode);
 257         cprintf("%s\n", config.c_fqdn);
 258         cprintf("%s\n", CITADEL);
 259         cprintf("%d\n", REV_LEVEL);
 260         cprintf("%s\n", config.c_site_location);
 261         cprintf("%s\n", config.c_sysadm);
 262         cprintf("%d\n", SERVER_TYPE);
 263         cprintf("%s\n", config.c_moreprompt);
 264         cprintf("1\n"); /* 1 = yes, this system supports floors */
 265         cprintf("1\n"); /* 1 = we support the extended paging options */
 266         cprintf("\n");  /* nonce no longer supported */
 267         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 268
 269 #ifdef HAVE_LDAP
 270         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
 271 #else
 272         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
 273 #endif
 274
 275         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 276                 cprintf("%d\n", config.c_disable_newu);
 277         }
 278         else {
 279                 cprintf("1\n"); /* "create new user" does not work with non-native auth modes */
 280         }
 281
 282         cprintf("%s\n", config.c_default_cal_zone);
 283
 284         /* Output load averages */
 285         cprintf("%f\n", CtdlThreadLoadAvg);
 286         cprintf("%f\n", CtdlThreadWorkerAvg);
 287         cprintf("%d\n", CtdlThreadGetCount());
 288
 289         cprintf("1\n");         /* yes, Sieve mail filtering is supported */
 290         cprintf("%d\n", config.c_enable_fulltext);
 291         cprintf("%s\n", svn_revision());
 292
 293         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 294                 cprintf("%d\n", openid_level_supported); /* OpenID is enabled when using native auth */
 295         }
 296         else {
 297                 cprintf("0\n"); /* OpenID is disabled when using non-native auth */
 298         }
 299
 300         cprintf("%d\n", config.c_guest_logins);
 301
 302         cprintf("000\n");
 303 }
 304
 305
 306 /*
 307  * returns an asterisk if there are any instant messages waiting,
 308  * space otherwise.
 309  */
 310 char CtdlCheckExpress(void) {
 311         if (CC->FirstExpressMessage == NULL) {
 312                 return(' ');
 313         }
 314         else {
 315                 return('*');
 316         }
 317 }
 318
 319 void cmd_time(char *argbuf)
 320 {
 321    time_t tv;
 322    struct tm tmp;
 323
 324    tv = time(NULL);
 325    localtime_r(&tv, &tmp);
 326
 327    /* timezone and daylight global variables are not portable. */
 328 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 329    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst);
 330 #else
 331    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst);
 332 #endif
 333 }
 334
 335
 336 /*
 337  * Check originating host against the public_clients file.  This determines
 338  * whether the client is allowed to change the hostname for this session
 339  * (for example, to show the location of the user rather than the location
 340  * of the client).
 341  */
 342 int is_public_client(void)
 343 {
 344         char buf[1024];
 345         char addrbuf[1024];
 346         FILE *fp;
 347         int i;
 348         char *public_clientspos;
 349         char *public_clientsend;
 350         char *paddr = NULL;
 351         struct stat statbuf;
 352         static time_t pc_timestamp = 0;
 353         static char public_clients[SIZ];
 354         static char public_clients_file[SIZ];
 355
 356 #define LOCALHOSTSTR "127.0.0.1"
 357
 358         snprintf(public_clients_file, sizeof public_clients_file, "%s/public_clients", ctdl_etc_dir);
 359
 360         /*
 361          * Check the time stamp on the public_clients file.  If it's been
 362          * updated since the last time we were here (or if this is the first
 363          * time we've been through the loop), read its contents and learn
 364          * the IP addresses of the listed hosts.
 365          */
 366         if (stat(public_clients_file, &statbuf) != 0) {
 367                 /* No public_clients file exists, so bail out */
 368                 syslog(LOG_WARNING, "Warning: '%s' does not exist\n",
 369                                 public_clients_file);
 370                 return(0);
 371         }
 372
 373         if (statbuf.st_mtime > pc_timestamp) {
 374                 begin_critical_section(S_PUBLIC_CLIENTS);
 375                 syslog(LOG_INFO, "Loading %s\n", public_clients_file);
 376
 377                 public_clientspos = &public_clients[0];
 378                 public_clientsend = public_clientspos + SIZ;
 379                 safestrncpy(public_clientspos, LOCALHOSTSTR, sizeof public_clients);
 380                 public_clientspos += sizeof(LOCALHOSTSTR) - 1;
 381
 382                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 383                         *(public_clientspos++) = '|';
 384                         paddr = &addrbuf[0];
 385                         while (!IsEmptyStr (paddr) &&
 386                                (public_clientspos < public_clientsend))
 387                                 *(public_clientspos++) = *(paddr++);
 388                 }
 389
 390                 fp = fopen(public_clients_file, "r");
 391                 if (fp != NULL)
 392                         while ((fgets(buf, sizeof buf, fp)!=NULL) &&
 393                                (public_clientspos < public_clientsend)){
 394                                 char *ptr;
 395                                 ptr = buf;
 396                                 while (!IsEmptyStr(ptr)) {
 397                                         if (*ptr == '#') {
 398                                                 *ptr = 0;
 399                                                 break;
 400                                         }
 401                                 else ptr++;
 402                                 }
 403                                 ptr--;
 404                                 while (ptr>buf && isspace(*ptr)) {
 405                                         *(ptr--) = 0;
 406                                 }
 407                                 if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 408                                         *(public_clientspos++) = '|';
 409                                         paddr = addrbuf;
 410                                         while (!IsEmptyStr(paddr) &&
 411                                                (public_clientspos < public_clientsend)){
 412                                                 *(public_clientspos++) = *(paddr++);
 413                                         }
 414                                 }
 415                         }
 416                 fclose(fp);
 417                 pc_timestamp = time(NULL);
 418                 end_critical_section(S_PUBLIC_CLIENTS);
 419         }
 420
 421         syslog(LOG_DEBUG, "Checking whether %s is a local or public client\n",
 422                 CC->cs_addr);
 423         for (i=0; i<num_parms(public_clients); ++i) {
 424                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 425                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 426                         syslog(LOG_DEBUG, "... yes it is.\n");
 427                         return(1);
 428                 }
 429         }
 430
 431         /* No hits.  This is not a public client. */
 432         syslog(LOG_DEBUG, "... no it isn't.\n");
 433         return(0);
 434 }
 435
 436
 437 /*
 438  * the client is identifying itself to the server
 439  */
 440 void cmd_iden(char *argbuf)
 441 {
 442         int dev_code;
 443         int cli_code;
 444         int rev_level;
 445         char desc[128];
 446         char from_host[128];
 447
 448         if (num_parms(argbuf)<4) {
 449                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
 450                 return;
 451         }
 452
 453         dev_code = extract_int(argbuf,0);
 454         cli_code = extract_int(argbuf,1);
 455         rev_level = extract_int(argbuf,2);
 456         extract_token(desc, argbuf, 3, '|', sizeof desc);
 457
 458         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 459         from_host[sizeof from_host - 1] = 0;
 460         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
 461
 462         CC->cs_clientdev = dev_code;
 463         CC->cs_clienttyp = cli_code;
 464         CC->cs_clientver = rev_level;
 465         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 466         CC->cs_clientname[31] = 0;
 467
 468         /* For local sockets and public clients, trust the hostname supplied by the client */
 469         if ( (CC->is_local_socket) || (is_public_client()) ) {
 470                 safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 471                 CC->cs_host[sizeof CC->cs_host - 1] = 0;
 472                 CC->cs_addr[0] = 0;
 473         }
 474
 475         syslog(LOG_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
 476                 dev_code,
 477                 cli_code,
 478                 (rev_level / 100),
 479                 (rev_level % 100),
 480                 desc,
 481                 CC->cs_host
 482         );
 483         cprintf("%d Ok\n",CIT_OK);
 484 }
 485
 486
 487 /*
 488  * display system messages or help
 489  */
 490 void cmd_mesg(char *mname)
 491 {
 492         FILE *mfp;
 493         char targ[256];
 494         char buf[256];
 495         char buf2[256];
 496         char *dirs[2];
 497         DIR *dp;
 498         struct dirent *d;
 499
 500         extract_token(buf, mname, 0, '|', sizeof buf);
 501
 502         dirs[0] = strdup(ctdl_message_dir);
 503         dirs[1] = strdup(ctdl_hlp_dir);
 504
 505         snprintf(buf2, sizeof buf2, "%s.%d.%d",
 506                 buf, CC->cs_clientdev, CC->cs_clienttyp);
 507
 508         /* If the client requested "?" then produce a listing */
 509         if (!strcmp(buf, "?")) {
 510                 cprintf("%d %s\n", LISTING_FOLLOWS, buf);
 511                 dp = opendir(dirs[1]);
 512                 if (dp != NULL) {
 513                         while (d = readdir(dp), d != NULL) {
 514                                 if (d->d_name[0] != '.') {
 515                                         cprintf(" %s\n", d->d_name);
 516                                 }
 517                         }
 518                         closedir(dp);
 519                 }
 520                 cprintf("000\n");
 521                 free(dirs[0]);
 522                 free(dirs[1]);
 523                 return;
 524         }
 525
 526         /* Otherwise, look for the requested file by name. */
 527         else {
 528                 mesg_locate(targ, sizeof targ, buf2, 2, (const char **)dirs);
 529                 if (IsEmptyStr(targ)) {
 530                         snprintf(buf2, sizeof buf2, "%s.%d",
 531                                                         buf, CC->cs_clientdev);
 532                         mesg_locate(targ, sizeof targ, buf2, 2,
 533                                                         (const char **)dirs);
 534                         if (IsEmptyStr(targ)) {
 535                                 mesg_locate(targ, sizeof targ, buf, 2,
 536                                                         (const char **)dirs);
 537                         }
 538                 }
 539         }
 540
 541         free(dirs[0]);
 542         free(dirs[1]);
 543
 544         if (IsEmptyStr(targ)) {
 545                 cprintf("%d '%s' not found.  (Searching in %s and %s)\n",
 546                         ERROR + FILE_NOT_FOUND,
 547                         mname,
 548                         ctdl_message_dir,
 549                         ctdl_hlp_dir
 550                 );
 551                 return;
 552         }
 553
 554         mfp = fopen(targ, "r");
 555         if (mfp==NULL) {
 556                 cprintf("%d Cannot open '%s': %s\n",
 557                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 558                 return;
 559         }
 560         cprintf("%d %s\n", LISTING_FOLLOWS,buf);
 561
 562         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
 563                 buf[strlen(buf)-1] = 0;
 564                 do_help_subst(buf);
 565                 cprintf("%s\n",buf);
 566         }
 567
 568         fclose(mfp);
 569         cprintf("000\n");
 570 }
 571
 572
 573 /*
 574  * enter system messages or help
 575  */
 576 void cmd_emsg(char *mname)
 577 {
 578         FILE *mfp;
 579         char targ[256];
 580         char buf[256];
 581         char *dirs[2];
 582         int a;
 583
 584         unbuffer_output();
 585
 586         if (CtdlAccessCheck(ac_aide)) return;
 587
 588         extract_token(buf, mname, 0, '|', sizeof buf);
 589         for (a=0; !IsEmptyStr(&buf[a]); ++a) {          /* security measure */
 590                 if (buf[a] == '/') buf[a] = '.';
 591         }
 592
 593         dirs[0] = strdup(ctdl_message_dir);
 594         dirs[1] = strdup(ctdl_hlp_dir);
 595
 596         mesg_locate(targ, sizeof targ, buf, 2, (const char**)dirs);
 597         free(dirs[0]);
 598         free(dirs[1]);
 599
 600         if (IsEmptyStr(targ)) {
 601                 snprintf(targ, sizeof targ,
 602                                  "%s/%s",
 603                                  ctdl_hlp_dir, buf);
 604         }
 605
 606         mfp = fopen(targ,"w");
 607         if (mfp==NULL) {
 608                 cprintf("%d Cannot open '%s': %s\n",
 609                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 610                 return;
 611         }
 612         cprintf("%d %s\n", SEND_LISTING, targ);
 613
 614         while (client_getln(buf, sizeof buf) >=0 && strcmp(buf, "000")) {
 615                 fprintf(mfp, "%s\n", buf);
 616         }
 617
 618         fclose(mfp);
 619 }
 620
 621
 622 /* Don't show the names of private rooms unless the viewing
 623  * user also knows the rooms.
 624  */
 625 void GenerateRoomDisplay(char *real_room,
 626                         CitContext *viewed,
 627                         CitContext *viewer) {
 628
 629         int ra;
 630
 631         strcpy(real_room, viewed->room.QRname);
 632         if (viewed->room.QRflags & QR_MAILBOX) {
 633                 strcpy(real_room, &real_room[11]);
 634         }
 635         if (viewed->room.QRflags & QR_PRIVATE) {
 636                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
 637                 if ( (ra & UA_KNOWN) == 0) {
 638                         strcpy(real_room, "<private room>");
 639                 }
 640         }
 641
 642         if (viewed->cs_flags & CS_CHAT) {
 643                 while (strlen(real_room) < 14) {
 644                         strcat(real_room, " ");
 645                 }
 646                 strcpy(&real_room[14], "<chat>");
 647         }
 648
 649 }
 650
 651 /*
 652  * Convenience function.
 653  */
 654 int CtdlAccessCheck(int required_level) {
 655
 656         if (CC->internal_pgm) return(0);
 657         if (required_level >= ac_internal) {
 658                 cprintf("%d This is not a user-level command.\n",
 659                         ERROR + HIGHER_ACCESS_REQUIRED);
 660                 return(-1);
 661         }
 662
 663         if ((required_level >= ac_logged_in_or_guest) && (CC->logged_in == 0) && (!config.c_guest_logins)) {
 664                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 665                 return(-1);
 666         }
 667
 668         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
 669                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 670                 return(-1);
 671         }
 672
 673         if (CC->user.axlevel >= AxAideU) return(0);
 674         if (required_level >= ac_aide) {
 675                 cprintf("%d This command requires Aide access.\n",
 676                         ERROR + HIGHER_ACCESS_REQUIRED);
 677                 return(-1);
 678         }
 679
 680         if (is_room_aide()) return(0);
 681         if (required_level >= ac_room_aide) {
 682                 cprintf("%d This command requires Aide or Room Aide access.\n",
 683                         ERROR + HIGHER_ACCESS_REQUIRED);
 684                 return(-1);
 685         }
 686
 687         /* shhh ... succeed quietly */
 688         return(0);
 689 }
 690
 691
 692
 693 /*
 694  * Terminate another running session
 695  */
 696 void cmd_term(char *cmdbuf)
 697 {
 698         int session_num;
 699         int terminated = 0;
 700
 701         session_num = extract_int(cmdbuf, 0);
 702
 703         terminated = CtdlTerminateOtherSession(session_num);
 704
 705         if (terminated < 0) {
 706                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
 707                 return;
 708         }
 709
 710         if (terminated & TERM_FOUND) {
 711                 if (terminated == TERM_KILLED) {
 712                         cprintf("%d Session terminated.\n", CIT_OK);
 713                 }
 714                 else {
 715                         cprintf("%d You are not allowed to do that.\n",
 716                                 ERROR + HIGHER_ACCESS_REQUIRED);
 717                 }
 718         }
 719         else {
 720                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
 721         }
 722 }
 723
 724
 725 /*
 726  * get the paginator prompt
 727  */
 728 void cmd_more(char *argbuf) {
 729         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 730 }
 731
 732
 733 /*
 734  * echo
 735  */
 736 void cmd_echo(char *etext)
 737 {
 738         cprintf("%d %s\n", CIT_OK, etext);
 739 }
 740
 741
 742 /*
 743  * Perform privilege escalation for an internal program
 744  */
 745 void cmd_ipgm(char *argbuf)
 746 {
 747         int secret;
 748
 749         secret = extract_int(argbuf, 0);
 750
 751         /* For security reasons, we do NOT allow this command to run
 752          * over the network.  Local sockets only.
 753          */
 754         if (!CC->is_local_socket) {
 755                 sleep(5);
 756                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 757         }
 758         else if (secret == config.c_ipgm_secret) {
 759                 CC->internal_pgm = 1;
 760                 strcpy(CC->curr_user, "<internal program>");
 761                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 762                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
 763         }
 764         else {
 765                 sleep(5);
 766                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 767                 syslog(LOG_ERR, "Warning: ipgm authentication failed.\n");
 768                 CC->kill_me = KILLME_AUTHFAILED;
 769         }
 770 }
 771
 772
 773 /*
 774  * Shut down the server
 775  */
 776 void cmd_down(char *argbuf) {
 777         char *Reply ="%d Shutting down server.  Goodbye.\n";
 778
 779         if (CtdlAccessCheck(ac_aide)) return;
 780
 781         if (!IsEmptyStr(argbuf))
 782         {
 783                 int state = CIT_OK;
 784                 restart_server = extract_int(argbuf, 0);
 785
 786                 if (restart_server > 0)
 787                 {
 788                         Reply = "%d citserver will now shut down and automatically restart.\n";
 789                 }
 790                 if ((restart_server > 0) && !running_as_daemon)
 791                 {
 792                         syslog(LOG_ERR, "The user requested restart, but not running as daemon! Geronimooooooo!\n");
 793                         Reply = "%d Warning: citserver is not running in daemon mode and is therefore unlikely to restart automatically.\n";
 794                         state = ERROR;
 795                 }
 796                 cprintf(Reply, state);
 797         }
 798         else
 799         {
 800                 cprintf(Reply, CIT_OK + SERVER_SHUTTING_DOWN);
 801         }
 802         CC->kill_me = KILLME_SERVER_SHUTTING_DOWN;
 803         CtdlThreadStopAll();
 804 }
 805
 806
 807 /*
 808  * Halt the server without exiting the server process.
 809  */
 810 void cmd_halt(char *argbuf) {
 811
 812         if (CtdlAccessCheck(ac_aide)) return;
 813
 814         cprintf("%d Halting server.  Goodbye.\n", CIT_OK);
 815         CtdlThreadStopAll();
 816         shutdown_and_halt = 1;
 817 }
 818
 819
 820 /*
 821  * Schedule or cancel a server shutdown
 822  */
 823 void cmd_scdn(char *argbuf)
 824 {
 825         int new_state;
 826         int state = CIT_OK;
 827         char *Reply = "%d %d\n";
 828
 829         if (CtdlAccessCheck(ac_aide)) return;
 830
 831         new_state = extract_int(argbuf, 0);
 832         if ((new_state == 2) || (new_state == 3))
 833         {
 834                 restart_server = 1;
 835                 if (!running_as_daemon)
 836                 {
 837                         syslog(LOG_ERR, "The user requested restart, but not running as deamon! Geronimooooooo!\n");
 838                         Reply = "%d %d Warning, not running in deamon mode. maybe we will come up again, but don't lean on it.\n";
 839                         state = ERROR;
 840                 }
 841
 842                 restart_server = extract_int(argbuf, 0);
 843                 new_state -= 2;
 844         }
 845         if ((new_state == 0) || (new_state == 1)) {
 846                 ScheduledShutdown = new_state;
 847         }
 848         cprintf(Reply, state, ScheduledShutdown);
 849 }
 850
 851
 852 /*
 853  * Set or unset asynchronous protocol mode
 854  */
 855 void cmd_asyn(char *argbuf)
 856 {
 857         int new_state;
 858
 859         new_state = extract_int(argbuf, 0);
 860         if ((new_state == 0) || (new_state == 1)) {
 861                 CC->is_async = new_state;
 862         }
 863         cprintf("%d %d\n", CIT_OK, CC->is_async);
 864 }
 865
 866
 867
 868 /*
 869  * Back-end function for starting a session
 870  */
 871 void begin_session(CitContext *con)
 872 {
 873         socklen_t len;
 874         struct sockaddr_in sin;
 875
 876         /*
 877          * Initialize some variables specific to our context.
 878          */
 879         con->logged_in = 0;
 880         con->internal_pgm = 0;
 881         con->download_fp = NULL;
 882         con->upload_fp = NULL;
 883         con->cached_msglist = NULL;
 884         con->cached_num_msgs = 0;
 885         con->FirstExpressMessage = NULL;
 886         time(&con->lastcmd);
 887         time(&con->lastidle);
 888         strcpy(con->lastcmdname, "    ");
 889         strcpy(con->cs_clientname, "(unknown)");
 890         strcpy(con->curr_user, NLI);
 891         *con->net_node = '\0';
 892         *con->fake_username = '\0';
 893         *con->fake_hostname = '\0';
 894         *con->fake_roomname = '\0';
 895         *con->cs_clientinfo = '\0';
 896         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 897         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 898         con->cs_UDSclientUID = -1;
 899         con->cs_host[sizeof con->cs_host - 1] = 0;
 900         len = sizeof sin;
 901         if (!CC->is_local_socket) {
 902                 locate_host(con->cs_host, sizeof con->cs_host,
 903                         con->cs_addr, sizeof con->cs_addr,
 904                         con->client_socket
 905                 );
 906         }
 907         else {
 908                 con->cs_host[0] = 0;
 909                 con->cs_addr[0] = 0;
 910 #ifdef HAVE_STRUCT_UCRED
 911                 {
 912                         /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
 913                         struct ucred credentials;
 914                         socklen_t ucred_length = sizeof(struct ucred);
 915
 916                         /*fill in the user data structure */
 917                         if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
 918                                 syslog(LOG_NOTICE, "could obtain credentials from unix domain socket");
 919
 920                         }
 921                         else {
 922                                 /* the process ID of the process on the other side of the socket */
 923                                 /* credentials.pid; */
 924
 925                                 /* the effective UID of the process on the other side of the socket  */
 926                                 con->cs_UDSclientUID = credentials.uid;
 927
 928                                 /* the effective primary GID of the process on the other side of the socket */
 929                                 /* credentials.gid; */
 930
 931                                 /* To get supplemental groups, we will have to look them up in our account
 932                                    database, after a reverse lookup on the UID to get the account name.
 933                                    We can take this opportunity to check to see if this is a legit account.
 934                                 */
 935                                 snprintf(con->cs_clientinfo, sizeof(con->cs_clientinfo),
 936                                          "PID: "F_PID_T"; UID: "F_UID_T"; GID: "F_XPID_T" ",
 937                                          credentials.pid,
 938                                          credentials.uid,
 939                                          credentials.gid);
 940                         }
 941                 }
 942 #endif
 943         }
 944         con->cs_flags = 0;
 945         con->upload_type = UPL_FILE;
 946         con->dl_is_net = 0;
 947
 948         con->nologin = 0;
 949         if (((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions)) || CtdlWantSingleUser()) {
 950                 con->nologin = 1;
 951         }
 952
 953         if (!CC->is_local_socket) {
 954                 syslog(LOG_NOTICE, "Session (%s) started from %s (%s).\n", con->ServiceName, con->cs_host, con->cs_addr);
 955         }
 956         else {
 957                 syslog(LOG_NOTICE, "Session (%s) started via local socket UID:%d.\n", con->ServiceName, con->cs_UDSclientUID);
 958         }
 959
 960         /* Run any session startup routines registered by loadable modules */
 961         PerformSessionHooks(EVT_START);
 962 }
 963
 964
 965 void citproto_begin_session() {
 966         if (CC->nologin==1) {
 967                 cprintf("%d %s: Too many users are already online (maximum is %d)\n",
 968                         ERROR + MAX_SESSIONS_EXCEEDED,
 969                         config.c_nodename, config.c_maxsessions
 970                 );
 971                 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
 972         }
 973         else {
 974                 cprintf("%d %s Citadel server ready.\n", CIT_OK, config.c_nodename);
 975                 CC->can_receive_im = 1;
 976         }
 977 }
 978
 979
 980 void cmd_noop(char *argbuf)
 981 {
 982         cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
 983 }
 984
 985
 986 void cmd_qnop(char *argbuf)
 987 {
 988         /* do nothing, this command returns no response */
 989 }
 990
 991
 992 void cmd_quit(char *argbuf)
 993 {
 994         cprintf("%d Goodbye.\n", CIT_OK);
 995         CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
 996 }
 997
 998
 999 void cmd_lout(char *argbuf)
1000 {
1001         if (CC->logged_in)
1002                 CtdlUserLogout();
1003         cprintf("%d logged out.\n", CIT_OK);
1004 }
1005
1006
1007 /*
1008  * This loop recognizes all server commands.
1009  */
1010 void do_command_loop(void) {
1011         char cmdbuf[SIZ];
1012         const char *old_name = NULL;
1013
1014         old_name = CtdlThreadName("do_command_loop");
1015
1016         time(&CC->lastcmd);
1017         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
1018         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
1019                 syslog(LOG_ERR, "Citadel client disconnected: ending session.\n");
1020                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1021                 CtdlThreadName(old_name);
1022                 return;
1023         }
1024
1025         /* Log the server command, but don't show passwords... */
1026         if ( (strncasecmp(cmdbuf, "PASS", 4)) && (strncasecmp(cmdbuf, "SETP", 4)) ) {
1027                 syslog(LOG_INFO, "CtdlCommand [%s] [%s] %s\n", CTDLUSERIP, CC->curr_user, cmdbuf);
1028         }
1029         else {
1030                 syslog(LOG_INFO, "CtdlCommand [%s] [%s] <password command hidden from log>\n", CTDLUSERIP, CC->curr_user);
1031         }
1032
1033         buffer_output();
1034
1035         /*
1036          * Let other clients see the last command we executed, and
1037          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
1038          */
1039         if ( (strncasecmp(cmdbuf, "NOOP", 4))
1040            && (strncasecmp(cmdbuf, "QNOP", 4))
1041            && (strncasecmp(cmdbuf, "PEXP", 4))
1042            && (strncasecmp(cmdbuf, "GEXP", 4))
1043            && (strncasecmp(cmdbuf, "RWHO", 4))
1044            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
1045                 strcpy(CC->lastcmdname, "    ");
1046                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
1047                 time(&CC->lastidle);
1048         }
1049
1050         CtdlThreadName(cmdbuf);
1051
1052         if ((strncasecmp(cmdbuf, "ENT0", 4))
1053            && (strncasecmp(cmdbuf, "MESG", 4))
1054            && (strncasecmp(cmdbuf, "MSGS", 4)))
1055         {
1056            CC->cs_flags &= ~CS_POSTING;
1057         }
1058
1059         if (!DLoader_Exec_Cmd(cmdbuf)) {
1060                 cprintf("%d Unrecognized or unsupported command.\n", ERROR + CMD_NOT_SUPPORTED);
1061         }
1062
1063         unbuffer_output();
1064
1065         /* Run any after-each-command routines registered by modules */
1066         PerformSessionHooks(EVT_CMD);
1067         CtdlThreadName(old_name);
1068 }
1069
1070
1071 /*
1072  * This loop performs all asynchronous functions.
1073  */
1074 void do_async_loop(void) {
1075         PerformSessionHooks(EVT_ASYNC);
1076 }
1077
1078
1079 /*****************************************************************************/
1080 /*                      MODULE INITIALIZATION STUFF                          */
1081 /*****************************************************************************/
1082
1083 CTDL_MODULE_INIT(citserver)
1084 {
1085         if (!threading) {
1086                 CtdlRegisterProtoHook(cmd_noop, "NOOP", "no operation");
1087                 CtdlRegisterProtoHook(cmd_qnop, "QNOP", "no operation with no response");
1088                 CtdlRegisterProtoHook(cmd_quit, "QUIT", "log out and disconnect from server");
1089                 CtdlRegisterProtoHook(cmd_lout, "LOUT", "log out but do not disconnect from server");
1090                 CtdlRegisterProtoHook(cmd_asyn, "ASYN", "enable asynchronous server responses");
1091                 CtdlRegisterProtoHook(cmd_info, "INFO", "fetch server capabilities and configuration");
1092                 CtdlRegisterProtoHook(cmd_mesg, "MESG", "fetch system banners");
1093                 CtdlRegisterProtoHook(cmd_emsg, "EMSG", "submit system banners");
1094                 CtdlRegisterProtoHook(cmd_echo, "ECHO", "echo text back to the client");
1095                 CtdlRegisterProtoHook(cmd_more, "MORE", "fetch the paginator prompt");
1096                 CtdlRegisterProtoHook(cmd_iden, "IDEN", "identify the client software and location");
1097                 CtdlRegisterProtoHook(cmd_ipgm, "IPGM", "perform privilege escalation for internal programs");
1098                 CtdlRegisterProtoHook(cmd_term, "TERM", "terminate another running session");
1099                 CtdlRegisterProtoHook(cmd_down, "DOWN", "perform a server shutdown");
1100                 CtdlRegisterProtoHook(cmd_halt, "HALT", "halt the server without exiting the server process");
1101                 CtdlRegisterProtoHook(cmd_scdn, "SCDN", "schedule or cancel a server shutdown");
1102                 CtdlRegisterProtoHook(cmd_time, "TIME", "fetch the date and time from the server");
1103         }
1104         /* return our id for the Log */
1105         return "citserver";
1106 }