citadel/citserver.c

   1 /*
   2  * $Id$
   3  *
   4  * Main source module for the Citadel server
   5  *
   6  */
   7
   8 #include "sysdep.h"
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <stdio.h>
  12 #include <fcntl.h>
  13 #include <signal.h>
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16
  17
  18 #if TIME_WITH_SYS_TIME
  19 # include <sys/time.h>
  20 # include <time.h>
  21 #else
  22 # if HAVE_SYS_TIME_H
  23 #  include <sys/time.h>
  24 # else
  25 #  include <time.h>
  26 # endif
  27 #endif
  28
  29 #include <ctype.h>
  30 #include <string.h>
  31 #include <dirent.h>
  32 #include <errno.h>
  33 #include <limits.h>
  34 /* #include <dlfcn.h> */
  35 #include <netdb.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <netinet/in.h>
  39 #include <arpa/inet.h>
  40 #include "citadel.h"
  41 #include "server.h"
  42 #include "serv_extensions.h"
  43 #include "sysdep_decls.h"
  44 #include "citserver.h"
  45 #include "config.h"
  46 #include "database.h"
  47 #include "housekeeping.h"
  48 #include "user_ops.h"
  49 #include "msgbase.h"
  50 #include "support.h"
  51 #include "locate_host.h"
  52 #include "room_ops.h"
  53 #include "file_ops.h"
  54 #include "policy.h"
  55 #include "control.h"
  56 #include "tools.h"
  57 #include "euidindex.h"
  58
  59 #ifndef HAVE_SNPRINTF
  60 #include "snprintf.h"
  61 #endif
  62
  63 struct CitContext *ContextList = NULL;
  64 struct CitContext* next_session = NULL;
  65 char *unique_session_numbers;
  66 int ScheduledShutdown = 0;
  67 int do_defrag = 0;
  68 time_t server_startup_time;
  69 char pid_file_name[PATH_MAX];
  70
  71 /*
  72  * Various things that need to be initialized at startup
  73  */
  74 void master_startup(void) {
  75         struct timeval tv;
  76         unsigned int seed;
  77         FILE *urandom;
  78         struct ctdlroom qrbuf;
  79         FILE *pidfile_fp;
  80
  81         lprintf(CTDL_DEBUG, "master_startup() started\n");
  82         time(&server_startup_time);
  83
  84         /* pid file.  If we go FSSTND this should end up in 'localstatedir' */
  85         snprintf(pid_file_name, sizeof pid_file_name, "./citadel.pid");
  86         pidfile_fp = fopen(pid_file_name, "w");
  87         if (pidfile_fp != NULL) {
  88                 fprintf(pidfile_fp, "%d\n", (int)getpid());
  89                 fclose(pidfile_fp);
  90         }
  91
  92         lprintf(CTDL_INFO, "Opening databases\n");
  93         open_databases();
  94
  95         if (do_defrag) {
  96                 defrag_databases();
  97         }
  98
  99         check_ref_counts();
 100
 101         lprintf(CTDL_INFO, "Creating base rooms (if necessary)\n");
 102         create_room(config.c_baseroom,  0, "", 0, 1, 0, VIEW_BBS);
 103         create_room(AIDEROOM,           3, "", 0, 1, 0, VIEW_BBS);
 104         create_room(SYSCONFIGROOM,      3, "", 0, 1, 0, VIEW_BBS);
 105         create_room(config.c_twitroom,  0, "", 0, 1, 0, VIEW_BBS);
 106
 107         /* The "Local System Configuration" room doesn't need to be visible */
 108         if (lgetroom(&qrbuf, SYSCONFIGROOM) == 0) {
 109                 qrbuf.QRflags2 |= QR2_SYSTEM;
 110                 lputroom(&qrbuf);
 111         }
 112
 113         /*
 114          * Create a room in which we can deposit "deleted" messages for
 115          * deferred deletion.  This will silently fail if the room already
 116          * exists, and that's perfectly ok, because we want it to exist.
 117          */
 118         create_room(DELETED_MSGS_ROOM, 3, "", 0, 1, 0, VIEW_MAILBOX);
 119
 120         /*
 121          * Make sure it's set to be a "system room" so it doesn't show up
 122          * in the <K>nown rooms list for Aides.  Also set the message expire
 123          * policy to "by count, 1 message" so everything gets deleted all
 124          * the time (we can't set it to 0 because that's invalid, so we keep
 125          * a single message around).
 126          */
 127         if (lgetroom(&qrbuf, DELETED_MSGS_ROOM) == 0) {
 128                 qrbuf.QRflags2 |= QR2_SYSTEM;
 129                 qrbuf.QRep.expire_mode = EXPIRE_NUMMSGS;
 130                 qrbuf.QRep.expire_value = 1;
 131                 lputroom(&qrbuf);
 132         }
 133
 134         lprintf(CTDL_INFO, "Seeding the pseudo-random number generator...\n");
 135         urandom = fopen("/dev/urandom", "r");
 136         if (urandom != NULL) {
 137                 fread(&seed, sizeof seed, 1, urandom);
 138                 fclose(urandom);
 139         }
 140         else {
 141                 gettimeofday(&tv, NULL);
 142                 seed = tv.tv_usec;
 143         }
 144         srandom(seed);
 145
 146         lprintf(CTDL_INFO, "Initializing ipgm secret\n");
 147         get_config();
 148         config.c_ipgm_secret = rand();
 149         put_config();
 150
 151         lprintf(CTDL_DEBUG, "master_startup() finished\n");
 152 }
 153
 154
 155 /*
 156  * Cleanup routine to be called when the server is shutting down.
 157  */
 158 void master_cleanup(int exitcode) {
 159         struct CleanupFunctionHook *fcn;
 160         static int already_cleaning_up = 0;
 161
 162         if (already_cleaning_up) while(1) sleep(1);
 163         already_cleaning_up = 1;
 164
 165         /* Run any cleanup routines registered by loadable modules */
 166         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 167                 (*fcn->h_function_pointer)();
 168         }
 169
 170         /* Shut down the indexer thread */
 171         lprintf(CTDL_INFO, "Waiting for the indexer thread to shut down\n");
 172         pthread_join(indexer_thread_tid, NULL);
 173
 174         /* Shut down the checkpoint thread */
 175         lprintf(CTDL_INFO, "Waiting for the checkpoint thread to shut down\n");
 176         pthread_join(checkpoint_thread_tid, NULL);
 177
 178         /* Close databases */
 179         lprintf(CTDL_INFO, "Closing databases\n");
 180         close_databases();
 181
 182         /* Do system-dependent stuff */
 183         sysdep_master_cleanup();
 184
 185 #ifdef DEBUG_MEMORY_LEAKS
 186         dump_heap();
 187 #endif
 188
 189         /* Now go away. */
 190         lprintf(CTDL_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 191         fflush(stdout); fflush(stderr);
 192
 193         unlink(pid_file_name);
 194         exit(exitcode);
 195 }
 196
 197
 198
 199 /*
 200  * Terminate a session.
 201  */
 202 void RemoveContext (struct CitContext *con)
 203 {
 204         if (con==NULL) {
 205                 lprintf(CTDL_ERR,
 206                         "WARNING: RemoveContext() called with NULL!\n");
 207                 return;
 208         }
 209         lprintf(CTDL_DEBUG, "RemoveContext() session %d\n", con->cs_pid);
 210
 211         /* Run any cleanup routines registered by loadable modules.
 212          * Note: We have to "become_session()" because the cleanup functions
 213          *       might make references to "CC" assuming it's the right one.
 214          */
 215         become_session(con);
 216         PerformSessionHooks(EVT_STOP);
 217         become_session(NULL);
 218
 219         /* Now handle all of the administrivia. */
 220         lprintf(CTDL_DEBUG, "Calling logout(%d)\n", con->cs_pid);
 221         logout(con);
 222
 223         lprintf(CTDL_NOTICE, "[%3d] Session ended.\n", con->cs_pid);
 224
 225         /* If the client is still connected, blow 'em away. */
 226         lprintf(CTDL_DEBUG, "Closing socket %d\n", con->client_socket);
 227         close(con->client_socket);
 228
 229         lprintf(CTDL_DEBUG, "Done with RemoveContext()\n");
 230 }
 231
 232
 233
 234
 235
 236 /*
 237  * cmd_info()  -  tell the client about this server
 238  */
 239 void cmd_info(void) {
 240         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 241         cprintf("%d\n", CC->cs_pid);
 242         cprintf("%s\n", config.c_nodename);
 243         cprintf("%s\n", config.c_humannode);
 244         cprintf("%s\n", config.c_fqdn);
 245         cprintf("%s\n", CITADEL);
 246         cprintf("%d\n", REV_LEVEL);
 247         cprintf("%s\n", config.c_site_location);
 248         cprintf("%s\n", config.c_sysadm);
 249         cprintf("%d\n", SERVER_TYPE);
 250         cprintf("%s\n", config.c_moreprompt);
 251         cprintf("1\n"); /* 1 = yes, this system supports floors */
 252         cprintf("1\n"); /* 1 = we support the extended paging options */
 253         cprintf("%s\n", CC->cs_nonce);
 254         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 255 #ifdef HAVE_LDAP
 256         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
 257 #else
 258         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
 259 #endif
 260         cprintf("000\n");
 261 }
 262
 263
 264 /*
 265  * returns an asterisk if there are any instant messages waiting,
 266  * space otherwise.
 267  */
 268 char CtdlCheckExpress(void) {
 269         if (CC->FirstExpressMessage == NULL) {
 270                 return(' ');
 271         }
 272         else {
 273                 return('*');
 274         }
 275 }
 276
 277 void cmd_time(void)
 278 {
 279    time_t tv;
 280    struct tm tmp;
 281
 282    tv = time(NULL);
 283    localtime_r(&tv, &tmp);
 284
 285    /* timezone and daylight global variables are not portable. */
 286 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 287    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst);
 288 #else
 289    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst);
 290 #endif
 291 }
 292
 293
 294 /*
 295  * Check originating host against the public_clients file.  This determines
 296  * whether the client is allowed to change the hostname for this session
 297  * (for example, to show the location of the user rather than the location
 298  * of the client).
 299  */
 300 int is_public_client(void)
 301 {
 302         char buf[1024];
 303         char addrbuf[1024];
 304         FILE *fp;
 305         int i;
 306         struct stat statbuf;
 307         static time_t pc_timestamp = 0;
 308         static char public_clients[SIZ];
 309
 310 #ifndef HAVE_ETC
 311 #define PUBLIC_CLIENTS "./public_clients"
 312 #else
 313 #define PUBLIC_CLIENTS ETC_DIR"/public_clients"
 314 #endif
 315
 316         /*
 317          * Check the time stamp on the public_clients file.  If it's been
 318          * updated since the last time we were here (or if this is the first
 319          * time we've been through the loop), read its contents and learn
 320          * the IP addresses of the listed hosts.
 321          */
 322         if (stat(PUBLIC_CLIENTS, &statbuf) != 0) {
 323                 /* No public_clients file exists, so bail out */
 324                 lprintf(CTDL_WARNING, "Warning: '%s' does not exist\n", PUBLIC_CLIENTS);
 325                 return(0);
 326         }
 327
 328         if (statbuf.st_mtime > pc_timestamp) {
 329                 begin_critical_section(S_PUBLIC_CLIENTS);
 330                 lprintf(CTDL_INFO, "Loading %s\n", PUBLIC_CLIENTS);
 331
 332                 safestrncpy(public_clients, "127.0.0.1", sizeof public_clients);
 333                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 334                         strcat(public_clients, "|");
 335                         strcat(public_clients, addrbuf);
 336                 }
 337
 338                 fp = fopen(
 339 #ifndef HAVE_ETC
 340                                    "."
 341 #else
 342                                    ETC_DIR
 343 #endif
 344                                    "/public_clients", "r");
 345                 if (fp != NULL) while (fgets(buf, sizeof buf, fp)!=NULL) {
 346                         for (i=0; i<strlen(buf); ++i) {
 347                                 if (buf[i] == '#') buf[i] = 0;
 348                         }
 349                         while (isspace((buf[strlen(buf)-1]))) {
 350                                 buf[strlen(buf)-1] = 0;
 351                         }
 352                         if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 353                                 if ((strlen(public_clients) +
 354                                    strlen(addrbuf) + 2)
 355                                    < sizeof(public_clients)) {
 356                                         strcat(public_clients, addrbuf);
 357                                 }
 358                         }
 359                 }
 360                 fclose(fp);
 361                 pc_timestamp = time(NULL);
 362                 end_critical_section(S_PUBLIC_CLIENTS);
 363         }
 364
 365         lprintf(CTDL_DEBUG, "Checking whether %s is a local or public client\n",
 366                 CC->cs_addr);
 367         for (i=0; i<num_parms(public_clients); ++i) {
 368                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 369                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 370                         lprintf(CTDL_DEBUG, "... yes it is.\n");
 371                         return(1);
 372                 }
 373         }
 374
 375         /* No hits.  This is not a public client. */
 376         lprintf(CTDL_DEBUG, "... no it isn't.\n");
 377         return(0);
 378 }
 379
 380
 381 /*
 382  * the client is identifying itself to the server
 383  */
 384 void cmd_iden(char *argbuf)
 385 {
 386         int dev_code;
 387         int cli_code;
 388         int rev_level;
 389         char desc[128];
 390         char from_host[128];
 391         struct in_addr addr;
 392         int do_lookup = 0;
 393
 394         if (num_parms(argbuf)<4) {
 395                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
 396                 return;
 397         }
 398
 399         dev_code = extract_int(argbuf,0);
 400         cli_code = extract_int(argbuf,1);
 401         rev_level = extract_int(argbuf,2);
 402         extract_token(desc, argbuf, 3, '|', sizeof desc);
 403
 404         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 405         from_host[sizeof from_host - 1] = 0;
 406         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
 407
 408         CC->cs_clientdev = dev_code;
 409         CC->cs_clienttyp = cli_code;
 410         CC->cs_clientver = rev_level;
 411         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 412         CC->cs_clientname[31] = 0;
 413
 414         if (strlen(from_host) > 0) {
 415                 if (CC->is_local_socket) do_lookup = 1;
 416                 else if (is_public_client()) do_lookup = 1;
 417         }
 418
 419         if (do_lookup) {
 420                 lprintf(CTDL_DEBUG, "Looking up hostname '%s'\n", from_host);
 421                 if ((addr.s_addr = inet_addr(from_host)) != -1) {
 422                         locate_host(CC->cs_host, sizeof CC->cs_host,
 423                                 NULL, 0,
 424                                 &addr);
 425                 }
 426                 else {
 427                         safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 428                         CC->cs_host[sizeof CC->cs_host - 1] = 0;
 429                 }
 430         }
 431
 432         lprintf(CTDL_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
 433                 dev_code,
 434                 cli_code,
 435                 (rev_level / 100),
 436                 (rev_level % 100),
 437                 desc,
 438                 CC->cs_host);
 439         cprintf("%d Ok\n",CIT_OK);
 440 }
 441
 442
 443 /*
 444  * display system messages or help
 445  */
 446 void cmd_mesg(char *mname)
 447 {
 448         FILE *mfp;
 449         char targ[256];
 450         char buf[256];
 451         char buf2[256];
 452         char *dirs[2];
 453         DIR *dp;
 454         struct dirent *d;
 455
 456         extract_token(buf, mname, 0, '|', sizeof buf);
 457
 458 #ifdef HAVE_DATA_DIR
 459         dirs[0] = strdup(DATA_DIR "/messages");
 460 #else
 461         dirs[0] = strdup("messages");
 462 #endif
 463
 464 #ifdef HAVE_DATA_DIR
 465         dirs[1] = strdup(DATA_DIR "/help");
 466 #else
 467         dirs[1] = strdup("help");
 468 #endif
 469
 470         snprintf(buf2, sizeof buf2, "%s.%d.%d",
 471                 buf, CC->cs_clientdev, CC->cs_clienttyp);
 472
 473         /* If the client requested "?" then produce a listing */
 474         if (!strcmp(buf, "?")) {
 475                 cprintf("%d %s\n",LISTING_FOLLOWS,buf);
 476                 dp = opendir(dirs[1]);
 477                 if (dp != NULL) {
 478                         while (d = readdir(dp), d != NULL) {
 479                                 if (d->d_name[0] != '.') {
 480                                         cprintf(" %s\n", d->d_name);
 481                                 }
 482                         }
 483                         closedir(dp);
 484                 }
 485                 cprintf("000\n");
 486                 free(dirs[0]);
 487                 free(dirs[1]);
 488                 return;
 489         }
 490
 491         /* Otherwise, look for the requested file by name. */
 492         else {
 493                 mesg_locate(targ, sizeof targ, buf2, 2, (const char **)dirs);
 494                 if (strlen(targ) == 0) {
 495                         snprintf(buf2, sizeof buf2, "%s.%d",
 496                                                         buf, CC->cs_clientdev);
 497                         mesg_locate(targ, sizeof targ, buf2, 2,
 498                                                         (const char **)dirs);
 499                         if (strlen(targ) == 0) {
 500                                 mesg_locate(targ, sizeof targ, buf, 2,
 501                                                         (const char **)dirs);
 502                         }
 503                 }
 504         }
 505
 506         free(dirs[0]);
 507         free(dirs[1]);
 508
 509         if (strlen(targ)==0) {
 510                 cprintf("%d '%s' not found.\n",ERROR + FILE_NOT_FOUND, mname);
 511                 return;
 512         }
 513
 514         mfp = fopen(targ,"r");
 515         if (mfp==NULL) {
 516                 cprintf("%d Cannot open '%s': %s\n",
 517                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 518                 return;
 519         }
 520         cprintf("%d %s\n",LISTING_FOLLOWS,buf);
 521
 522         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
 523                 buf[strlen(buf)-1] = 0;
 524                 do_help_subst(buf);
 525                 cprintf("%s\n",buf);
 526         }
 527
 528         fclose(mfp);
 529         cprintf("000\n");
 530 }
 531
 532
 533 /*
 534  * enter system messages or help
 535  */
 536 void cmd_emsg(char *mname)
 537 {
 538         FILE *mfp;
 539         char targ[256];
 540         char buf[256];
 541         char *dirs[2];
 542         int a;
 543
 544         unbuffer_output();
 545
 546         if (CtdlAccessCheck(ac_aide)) return;
 547
 548         extract_token(buf, mname, 0, '|', sizeof buf);
 549         for (a=0; a<strlen(buf); ++a) {         /* security measure */
 550                 if (buf[a] == '/') buf[a] = '.';
 551         }
 552
 553 #ifdef HAVE_DATA_DIR
 554         dirs[0] = strdup(DATA_DIR "/messages");
 555 #else
 556         dirs[0] = strdup("messages");
 557 #endif
 558
 559 #ifdef HAVE_DATA_DIR
 560         dirs[1] = strdup(DATA_DIR "/help");
 561 #else
 562         dirs[1] = strdup("help");
 563 #endif
 564
 565         mesg_locate(targ, sizeof targ, buf, 2, (const char**)dirs);
 566         free(dirs[0]);
 567         free(dirs[1]);
 568
 569         if (strlen(targ)==0) {
 570                 snprintf(targ, sizeof targ,
 571 #ifndef HAVE_DATA_DIR
 572                          "."
 573 #else
 574                          DATA_DIR
 575 #endif
 576                                  "/help/%s", buf);
 577         }
 578
 579         mfp = fopen(targ,"w");
 580         if (mfp==NULL) {
 581                 cprintf("%d Cannot open '%s': %s\n",
 582                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 583                 return;
 584         }
 585         cprintf("%d %s\n", SEND_LISTING, targ);
 586
 587         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 588                 fprintf(mfp, "%s\n", buf);
 589         }
 590
 591         fclose(mfp);
 592 }
 593
 594
 595 /* Don't show the names of private rooms unless the viewing
 596  * user also knows the rooms.
 597  */
 598 void GenerateRoomDisplay(char *real_room,
 599                         struct CitContext *viewed,
 600                         struct CitContext *viewer) {
 601
 602         int ra;
 603
 604         strcpy(real_room, viewed->room.QRname);
 605         if (viewed->room.QRflags & QR_MAILBOX) {
 606                 strcpy(real_room, &real_room[11]);
 607         }
 608         if (viewed->room.QRflags & QR_PRIVATE) {
 609                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
 610                 if ( (ra & UA_KNOWN) == 0) {
 611                         strcpy(real_room, "<private room>");
 612                 }
 613         }
 614
 615         if (viewed->cs_flags & CS_CHAT) {
 616                 while (strlen(real_room) < 14)
 617                         strcat(real_room, " ");
 618
 619                 strcpy(&real_room[14], "<chat>");
 620         }
 621
 622 }
 623
 624 /*
 625  * Convenience function.
 626  */
 627 int CtdlAccessCheck(int required_level) {
 628
 629         if (CC->internal_pgm) return(0);
 630         if (required_level >= ac_internal) {
 631                 cprintf("%d This is not a user-level command.\n",
 632                         ERROR + HIGHER_ACCESS_REQUIRED);
 633                 return(-1);
 634         }
 635
 636         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
 637                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 638                 return(-1);
 639         }
 640
 641         if (CC->user.axlevel >= 6) return(0);
 642         if (required_level >= ac_aide) {
 643                 cprintf("%d This command requires Aide access.\n",
 644                         ERROR + HIGHER_ACCESS_REQUIRED);
 645                 return(-1);
 646         }
 647
 648         if (is_room_aide()) return(0);
 649         if (required_level >= ac_room_aide) {
 650                 cprintf("%d This command requires Aide or Room Aide access.\n",
 651                         ERROR + HIGHER_ACCESS_REQUIRED);
 652                 return(-1);
 653         }
 654
 655         /* shhh ... succeed quietly */
 656         return(0);
 657 }
 658
 659
 660
 661 /*
 662  * Terminate another running session
 663  */
 664 void cmd_term(char *cmdbuf)
 665 {
 666         int session_num;
 667         struct CitContext *ccptr;
 668         int found_it = 0;
 669         int allowed = 0;
 670
 671         session_num = extract_int(cmdbuf, 0);
 672         if (session_num == CC->cs_pid) {
 673                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
 674                 return;
 675         }
 676
 677         lprintf(CTDL_DEBUG, "Locating session to kill\n");
 678         begin_critical_section(S_SESSION_TABLE);
 679         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 680                 if (session_num == ccptr->cs_pid) {
 681                         found_it = 1;
 682                         if ((ccptr->user.usernum == CC->user.usernum)
 683                            || (CC->user.axlevel >= 6)) {
 684                                 allowed = 1;
 685                                 ccptr->kill_me = 1;
 686                         }
 687                         else {
 688                                 allowed = 0;
 689                         }
 690                 }
 691         }
 692         end_critical_section(S_SESSION_TABLE);
 693
 694         if (found_it) {
 695                 if (allowed) {
 696                         cprintf("%d Session terminated.\n", CIT_OK);
 697                 }
 698                 else {
 699                         cprintf("%d You are not allowed to do that.\n",
 700                                 ERROR + HIGHER_ACCESS_REQUIRED);
 701                 }
 702         }
 703         else {
 704                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
 705         }
 706 }
 707
 708
 709
 710
 711
 712 /*
 713  * get the paginator prompt
 714  */
 715 void cmd_more(void) {
 716         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 717 }
 718
 719 /*
 720  * echo
 721  */
 722 void cmd_echo(char *etext)
 723 {
 724         cprintf("%d %s\n", CIT_OK, etext);
 725 }
 726
 727
 728
 729 /*
 730  * identify as internal program
 731  */
 732 void cmd_ipgm(char *argbuf)
 733 {
 734         int secret;
 735
 736         secret = extract_int(argbuf, 0);
 737
 738         /* For security reasons, we do NOT allow this command to run
 739          * over the network.  Local sockets only.
 740          */
 741         if (!CC->is_local_socket) {
 742                 sleep(5);
 743                 cprintf("%d Authentication failed.\n",
 744                         ERROR + PASSWORD_REQUIRED);
 745         }
 746         else if (secret == config.c_ipgm_secret) {
 747                 CC->internal_pgm = 1;
 748                 strcpy(CC->curr_user, "<internal program>");
 749                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 750                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
 751         }
 752         else {
 753                 sleep(5);
 754                 cprintf("%d Authentication failed.\n",
 755                         ERROR + PASSWORD_REQUIRED);
 756                 lprintf(CTDL_ERR, "Warning: ipgm authentication failed.\n");
 757                 CC->kill_me = 1;
 758         }
 759
 760         /* Now change the ipgm secret for the next round.
 761          * (Disabled because it breaks concurrent scripts.  The fact that
 762          * we no longer accept IPGM over the network should be sufficient
 763          * to prevent brute-force attacks.  If you don't agree, uncomment
 764          * this block.)
 765         get_config();
 766         config.c_ipgm_secret = rand();
 767         put_config();
 768         */
 769 }
 770
 771
 772 /*
 773  * Shut down the server
 774  */
 775 void cmd_down(void) {
 776
 777         if (CtdlAccessCheck(ac_aide)) return;
 778
 779         cprintf("%d Shutting down server.  Goodbye.\n", CIT_OK);
 780         time_to_die = 1;
 781 }
 782
 783 /*
 784  * Schedule or cancel a server shutdown
 785  */
 786 void cmd_scdn(char *argbuf)
 787 {
 788         int new_state;
 789
 790         if (CtdlAccessCheck(ac_aide)) return;
 791
 792         new_state = extract_int(argbuf, 0);
 793         if ((new_state == 0) || (new_state == 1)) {
 794                 ScheduledShutdown = new_state;
 795         }
 796         cprintf("%d %d\n", CIT_OK, ScheduledShutdown);
 797 }
 798
 799
 800 /*
 801  * Set or unset asynchronous protocol mode
 802  */
 803 void cmd_asyn(char *argbuf)
 804 {
 805         int new_state;
 806
 807         new_state = extract_int(argbuf, 0);
 808         if ((new_state == 0) || (new_state == 1)) {
 809                 CC->is_async = new_state;
 810         }
 811         cprintf("%d %d\n", CIT_OK, CC->is_async);
 812 }
 813
 814
 815 /*
 816  * Generate a "nonce" for APOP-style authentication.
 817  *
 818  * RFC 1725 et al specify a PID to be placed in front of the nonce.
 819  * Quoth BTX: That would be stupid.
 820  */
 821 void generate_nonce(struct CitContext *con) {
 822         struct timeval tv;
 823
 824         memset(con->cs_nonce, NONCE_SIZE, 0);
 825         gettimeofday(&tv, NULL);
 826         memset(con->cs_nonce, NONCE_SIZE, 0);
 827         snprintf(con->cs_nonce, NONCE_SIZE, "<%d%ld@%s>",
 828                 rand(), (long)tv.tv_usec, config.c_fqdn);
 829 }
 830
 831
 832
 833
 834 /*
 835  * Back-end function for starting a session
 836  */
 837 void begin_session(struct CitContext *con)
 838 {
 839         int len;
 840         struct sockaddr_in sin;
 841
 842         /*
 843          * Initialize some variables specific to our context.
 844          */
 845         con->logged_in = 0;
 846         con->internal_pgm = 0;
 847         con->download_fp = NULL;
 848         con->upload_fp = NULL;
 849         con->FirstExpressMessage = NULL;
 850         time(&con->lastcmd);
 851         time(&con->lastidle);
 852         strcpy(con->lastcmdname, "    ");
 853         strcpy(con->cs_clientname, "(unknown)");
 854         strcpy(con->curr_user, NLI);
 855         strcpy(con->net_node, "");
 856         strcpy(con->fake_username, "");
 857         strcpy(con->fake_postname, "");
 858         strcpy(con->fake_hostname, "");
 859         strcpy(con->fake_roomname, "");
 860         generate_nonce(con);
 861         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 862         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 863         con->cs_host[sizeof con->cs_host - 1] = 0;
 864         len = sizeof sin;
 865         if (!CC->is_local_socket) {
 866                 if (!getpeername(con->client_socket,
 867                    (struct sockaddr *) &sin, &len))     /* should be socklen_t but doesn't work on Macintosh */
 868                         locate_host(con->cs_host, sizeof con->cs_host,
 869                                 con->cs_addr, sizeof con->cs_addr,
 870                                 &sin.sin_addr);
 871         }
 872         else {
 873                 strcpy(con->cs_host, "");
 874         }
 875         con->cs_flags = 0;
 876         con->upload_type = UPL_FILE;
 877         con->dl_is_net = 0;
 878
 879         con->nologin = 0;
 880         if ((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions))
 881                 con->nologin = 1;
 882
 883         lprintf(CTDL_NOTICE, "Session started.\n");
 884
 885         /* Run any session startup routines registered by loadable modules */
 886         PerformSessionHooks(EVT_START);
 887 }
 888
 889
 890 void citproto_begin_session() {
 891         if (CC->nologin==1) {
 892                 cprintf("%d %s: Too many users are already online "
 893                         "(maximum is %d)\n",
 894                         ERROR + MAX_SESSIONS_EXCEEDED,
 895                         config.c_nodename, config.c_maxsessions);
 896         }
 897         else {
 898                 cprintf("%d %s Citadel server ready.\n",
 899                         CIT_OK, config.c_nodename);
 900         }
 901 }
 902
 903
 904
 905
 906 /*
 907  * This loop recognizes all server commands.
 908  */
 909 void do_command_loop(void) {
 910         char cmdbuf[SIZ];
 911
 912         time(&CC->lastcmd);
 913         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 914         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
 915                 lprintf(CTDL_ERR, "Client disconnected: ending session.\n");
 916                 CC->kill_me = 1;
 917                 return;
 918         }
 919
 920         /* Log the server command, but don't show passwords... */
 921         if ( (strncasecmp(cmdbuf, "PASS", 4))
 922            && (strncasecmp(cmdbuf, "SETP", 4)) ) {
 923                 lprintf(CTDL_INFO, "%s\n", cmdbuf);
 924         }
 925         else {
 926                 lprintf(CTDL_INFO, "<password command sent>\n");
 927         }
 928
 929         buffer_output();
 930
 931         /*
 932          * Let other clients see the last command we executed, and
 933          * update the idle time, but not NOOP, QNOP, PEXP, or GEXP.
 934          */
 935         if ( (strncasecmp(cmdbuf, "NOOP", 4))
 936            && (strncasecmp(cmdbuf, "QNOP", 4))
 937            && (strncasecmp(cmdbuf, "PEXP", 4))
 938            && (strncasecmp(cmdbuf, "GEXP", 4)) ) {
 939                 strcpy(CC->lastcmdname, "    ");
 940                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
 941                 time(&CC->lastidle);
 942         }
 943
 944         if ((strncasecmp(cmdbuf, "ENT0", 4))
 945            && (strncasecmp(cmdbuf, "MESG", 4))
 946            && (strncasecmp(cmdbuf, "MSGS", 4)))
 947         {
 948            CC->cs_flags &= ~CS_POSTING;
 949         }
 950
 951         if (!strncasecmp(cmdbuf, "NOOP", 4)) {
 952                 cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
 953         }
 954
 955         else if (!strncasecmp(cmdbuf, "QNOP", 4)) {
 956                 /* do nothing, this command returns no response */
 957         }
 958
 959         else if (!strncasecmp(cmdbuf,"QUIT",4)) {
 960                 cprintf("%d Goodbye.\n", CIT_OK);
 961                 CC->kill_me = 1;
 962         }
 963
 964         else if (!strncasecmp(cmdbuf,"ASYN",4)) {
 965                 cmd_asyn(&cmdbuf[5]);
 966         }
 967
 968         else if (!strncasecmp(cmdbuf,"LOUT",4)) {
 969                 if (CC->logged_in) logout(CC);
 970                 cprintf("%d logged out.\n", CIT_OK);
 971         }
 972
 973         else if (!strncasecmp(cmdbuf,"USER",4)) {
 974                 cmd_user(&cmdbuf[5]);
 975         }
 976
 977         else if (!strncasecmp(cmdbuf,"PASS",4)) {
 978                 cmd_pass(&cmdbuf[5]);
 979         }
 980
 981         else if (!strncasecmp(cmdbuf,"NEWU",4)) {
 982                 cmd_newu(&cmdbuf[5]);
 983         }
 984
 985         else if (!strncasecmp(cmdbuf,"CREU",4)) {
 986                 cmd_creu(&cmdbuf[5]);
 987         }
 988
 989         else if (!strncasecmp(cmdbuf,"SETP",4)) {
 990                 cmd_setp(&cmdbuf[5]);
 991         }
 992
 993         else if (!strncasecmp(cmdbuf,"LRMS",4)) {
 994                 cmd_lrms(&cmdbuf[5]);
 995         }
 996
 997         else if (!strncasecmp(cmdbuf,"LKRA",4)) {
 998                 cmd_lkra(&cmdbuf[5]);
 999         }
1000
1001         else if (!strncasecmp(cmdbuf,"LKRN",4)) {
1002                 cmd_lkrn(&cmdbuf[5]);
1003         }
1004
1005         else if (!strncasecmp(cmdbuf,"LKRO",4)) {
1006                 cmd_lkro(&cmdbuf[5]);
1007         }
1008
1009         else if (!strncasecmp(cmdbuf,"LZRM",4)) {
1010                 cmd_lzrm(&cmdbuf[5]);
1011         }
1012
1013         else if (!strncasecmp(cmdbuf,"LPRM",4)) {
1014                 cmd_lprm(&cmdbuf[5]);
1015         }
1016
1017         else if (!strncasecmp(cmdbuf,"GETU",4)) {
1018                 cmd_getu();
1019         }
1020
1021         else if (!strncasecmp(cmdbuf,"SETU",4)) {
1022                 cmd_setu(&cmdbuf[5]);
1023         }
1024
1025         else if (!strncasecmp(cmdbuf,"GOTO",4)) {
1026                 cmd_goto(&cmdbuf[5]);
1027         }
1028
1029         else if (!strncasecmp(cmdbuf,"MSGS",4)) {
1030                 cmd_msgs(&cmdbuf[5]);
1031         }
1032
1033         else if (!strncasecmp(cmdbuf,"WHOK",4)) {
1034                 cmd_whok();
1035         }
1036
1037         else if (!strncasecmp(cmdbuf,"RDIR",4)) {
1038                 cmd_rdir();
1039         }
1040
1041         else if (!strncasecmp(cmdbuf,"EUID",4)) {
1042                 cmd_euid(&cmdbuf[5]);
1043         }
1044
1045         else if (!strncasecmp(cmdbuf,"MSG0",4)) {
1046                 cmd_msg0(&cmdbuf[5]);
1047         }
1048
1049         else if (!strncasecmp(cmdbuf,"MSG2",4)) {
1050                 cmd_msg2(&cmdbuf[5]);
1051         }
1052
1053         else if (!strncasecmp(cmdbuf,"MSG3",4)) {
1054                 cmd_msg3(&cmdbuf[5]);
1055         }
1056
1057         else if (!strncasecmp(cmdbuf,"MSG4",4)) {
1058                 cmd_msg4(&cmdbuf[5]);
1059         }
1060
1061         else if (!strncasecmp(cmdbuf,"MSGP",4)) {
1062                 cmd_msgp(&cmdbuf[5]);
1063         }
1064
1065         else if (!strncasecmp(cmdbuf,"OPNA",4)) {
1066                 cmd_opna(&cmdbuf[5]);
1067         }
1068
1069         else if (!strncasecmp(cmdbuf,"INFO",4)) {
1070                 cmd_info();
1071         }
1072
1073         else if (!strncasecmp(cmdbuf,"SLRP",4)) {
1074                 cmd_slrp(&cmdbuf[5]);
1075         }
1076
1077         else if (!strncasecmp(cmdbuf,"INVT",4)) {
1078                 cmd_invt_kick(&cmdbuf[5],1);
1079         }
1080
1081         else if (!strncasecmp(cmdbuf,"KICK",4)) {
1082                 cmd_invt_kick(&cmdbuf[5],0);
1083         }
1084
1085         else if (!strncasecmp(cmdbuf,"GETR",4)) {
1086                 cmd_getr();
1087         }
1088
1089         else if (!strncasecmp(cmdbuf,"SETR",4)) {
1090                 cmd_setr(&cmdbuf[5]);
1091         }
1092
1093         else if (!strncasecmp(cmdbuf,"GETA",4)) {
1094                 cmd_geta();
1095         }
1096
1097         else if (!strncasecmp(cmdbuf,"SETA",4)) {
1098                 cmd_seta(&cmdbuf[5]);
1099         }
1100
1101         else if (!strncasecmp(cmdbuf,"ENT0",4)) {
1102                 cmd_ent0(&cmdbuf[5]);
1103         }
1104
1105         else if (!strncasecmp(cmdbuf,"RINF",4)) {
1106                 cmd_rinf();
1107         }
1108
1109         else if (!strncasecmp(cmdbuf,"DELE",4)) {
1110                 cmd_dele(&cmdbuf[5]);
1111         }
1112
1113         else if (!strncasecmp(cmdbuf,"KILL",4)) {
1114                 cmd_kill(&cmdbuf[5]);
1115         }
1116
1117         else if (!strncasecmp(cmdbuf,"CRE8",4)) {
1118                 cmd_cre8(&cmdbuf[5]);
1119         }
1120
1121         else if (!strncasecmp(cmdbuf,"MOVE",4)) {
1122                 cmd_move(&cmdbuf[5]);
1123         }
1124
1125         else if (!strncasecmp(cmdbuf,"FORG",4)) {
1126                 cmd_forg();
1127         }
1128
1129         else if (!strncasecmp(cmdbuf,"MESG",4)) {
1130                 cmd_mesg(&cmdbuf[5]);
1131         }
1132
1133         else if (!strncasecmp(cmdbuf,"EMSG",4)) {
1134                 cmd_emsg(&cmdbuf[5]);
1135         }
1136
1137         else if (!strncasecmp(cmdbuf,"GNUR",4)) {
1138                 cmd_gnur();
1139         }
1140
1141         else if (!strncasecmp(cmdbuf,"VALI",4)) {
1142                 cmd_vali(&cmdbuf[5]);
1143         }
1144
1145         else if (!strncasecmp(cmdbuf,"EINF",4)) {
1146                 cmd_einf(&cmdbuf[5]);
1147         }
1148
1149         else if (!strncasecmp(cmdbuf,"LIST",4)) {
1150                 cmd_list(&cmdbuf[5]);
1151         }
1152
1153         else if (!strncasecmp(cmdbuf,"CHEK",4)) {
1154                 cmd_chek();
1155         }
1156
1157         else if (!strncasecmp(cmdbuf,"DELF",4)) {
1158                 cmd_delf(&cmdbuf[5]);
1159         }
1160
1161         else if (!strncasecmp(cmdbuf,"MOVF",4)) {
1162                 cmd_movf(&cmdbuf[5]);
1163         }
1164
1165         else if (!strncasecmp(cmdbuf,"NETF",4)) {
1166                 cmd_netf(&cmdbuf[5]);
1167         }
1168
1169         else if (!strncasecmp(cmdbuf,"OPEN",4)) {
1170                 cmd_open(&cmdbuf[5]);
1171         }
1172
1173         else if (!strncasecmp(cmdbuf,"CLOS",4)) {
1174                 cmd_clos();
1175         }
1176
1177         else if (!strncasecmp(cmdbuf,"UOPN",4)) {
1178                 cmd_uopn(&cmdbuf[5]);
1179         }
1180
1181         else if (!strncasecmp(cmdbuf,"UCLS",4)) {
1182                 cmd_ucls(&cmdbuf[5]);
1183         }
1184
1185         else if (!strncasecmp(cmdbuf,"READ",4)) {
1186                 cmd_read(&cmdbuf[5]);
1187         }
1188
1189         else if (!strncasecmp(cmdbuf,"WRIT",4)) {
1190                 cmd_writ(&cmdbuf[5]);
1191         }
1192
1193         else if (!strncasecmp(cmdbuf,"QUSR",4)) {
1194                 cmd_qusr(&cmdbuf[5]);
1195         }
1196
1197         else if (!strncasecmp(cmdbuf,"ECHO",4)) {
1198                 cmd_echo(&cmdbuf[5]);
1199         }
1200
1201         else if (!strncasecmp(cmdbuf,"OIMG",4)) {
1202                 cmd_oimg(&cmdbuf[5]);
1203         }
1204
1205         else if (!strncasecmp(cmdbuf,"MORE",4)) {
1206                 cmd_more();
1207         }
1208
1209         else if (!strncasecmp(cmdbuf,"NDOP",4)) {
1210                 cmd_ndop(&cmdbuf[5]);
1211         }
1212
1213         else if (!strncasecmp(cmdbuf,"NUOP",4)) {
1214                 cmd_nuop(&cmdbuf[5]);
1215         }
1216
1217         else if (!strncasecmp(cmdbuf,"LFLR",4)) {
1218                 cmd_lflr();
1219         }
1220
1221         else if (!strncasecmp(cmdbuf,"CFLR",4)) {
1222                 cmd_cflr(&cmdbuf[5]);
1223         }
1224
1225         else if (!strncasecmp(cmdbuf,"KFLR",4)) {
1226                 cmd_kflr(&cmdbuf[5]);
1227         }
1228
1229         else if (!strncasecmp(cmdbuf,"EFLR",4)) {
1230                 cmd_eflr(&cmdbuf[5]);
1231         }
1232
1233         else if (!strncasecmp(cmdbuf,"IDEN",4)) {
1234                 cmd_iden(&cmdbuf[5]);
1235         }
1236
1237         else if (!strncasecmp(cmdbuf,"IPGM",4)) {
1238                 cmd_ipgm(&cmdbuf[5]);
1239         }
1240
1241         else if (!strncasecmp(cmdbuf,"TERM",4)) {
1242                 cmd_term(&cmdbuf[5]);
1243         }
1244
1245         else if (!strncasecmp(cmdbuf,"DOWN",4)) {
1246                 cmd_down();
1247         }
1248
1249         else if (!strncasecmp(cmdbuf,"SCDN",4)) {
1250                 cmd_scdn(&cmdbuf[5]);
1251         }
1252
1253         else if (!strncasecmp(cmdbuf, "UIMG", 4)) {
1254                 cmd_uimg(&cmdbuf[5]);
1255         }
1256
1257         else if (!strncasecmp(cmdbuf, "TIME", 4)) {
1258                 cmd_time();
1259         }
1260
1261         else if (!strncasecmp(cmdbuf, "AGUP", 4)) {
1262                 cmd_agup(&cmdbuf[5]);
1263         }
1264
1265         else if (!strncasecmp(cmdbuf, "ASUP", 4)) {
1266                 cmd_asup(&cmdbuf[5]);
1267         }
1268
1269         else if (!strncasecmp(cmdbuf, "GPEX", 4)) {
1270                 cmd_gpex(&cmdbuf[5]);
1271         }
1272
1273         else if (!strncasecmp(cmdbuf, "SPEX", 4)) {
1274                 cmd_spex(&cmdbuf[5]);
1275         }
1276
1277         else if (!strncasecmp(cmdbuf, "CONF", 4)) {
1278                 cmd_conf(&cmdbuf[5]);
1279         }
1280
1281         else if (!strncasecmp(cmdbuf, "SEEN", 4)) {
1282                 cmd_seen(&cmdbuf[5]);
1283         }
1284
1285         else if (!strncasecmp(cmdbuf, "GTSN", 4)) {
1286                 cmd_gtsn(&cmdbuf[5]);
1287         }
1288
1289         else if (!strncasecmp(cmdbuf, "VIEW", 4)) {
1290                 cmd_view(&cmdbuf[5]);
1291         }
1292
1293         else if (!strncasecmp(cmdbuf, "ISME", 4)) {
1294                 cmd_isme(&cmdbuf[5]);
1295         }
1296
1297         else if (!DLoader_Exec_Cmd(cmdbuf)) {
1298                 cprintf("%d Unrecognized or unsupported command.\n",
1299                         ERROR + CMD_NOT_SUPPORTED);
1300                }
1301
1302         unbuffer_output();
1303
1304         /* Run any after-each-command routines registered by modules */
1305         PerformSessionHooks(EVT_CMD);
1306 }
1307
1308
1309 /*
1310  * This loop performs all asynchronous functions.
1311  */
1312 void do_async_loop(void) {
1313         PerformSessionHooks(EVT_ASYNC);
1314 }