citadel/citserver.c

   1 /*
   2  * $Id$
   3  *
   4  * Main source module for the Citadel server
   5  *
   6  */
   7
   8 #ifdef DLL_EXPORT
   9 #define IN_LIBCIT
  10 #endif
  11
  12 #include "sysdep.h"
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <stdio.h>
  16 #include <fcntl.h>
  17 #include <signal.h>
  18 #include <sys/types.h>
  19 #include <sys/stat.h>
  20
  21
  22 #if TIME_WITH_SYS_TIME
  23 # include <sys/time.h>
  24 # include <time.h>
  25 #else
  26 # if HAVE_SYS_TIME_H
  27 #  include <sys/time.h>
  28 # else
  29 #  include <time.h>
  30 # endif
  31 #endif
  32
  33 #include <ctype.h>
  34 #include <string.h>
  35 #include <errno.h>
  36 #include <limits.h>
  37 #include <syslog.h>
  38 /* #include <dlfcn.h> */
  39 #include <netdb.h>
  40 #include <sys/types.h>
  41 #include <sys/socket.h>
  42 #include <netinet/in.h>
  43 #include <arpa/inet.h>
  44 #include "citadel.h"
  45 #include "server.h"
  46 #include "serv_extensions.h"
  47 #include "sysdep_decls.h"
  48 #include "citserver.h"
  49 #include "config.h"
  50 #include "database.h"
  51 #include "housekeeping.h"
  52 #include "user_ops.h"
  53 #include "msgbase.h"
  54 #include "support.h"
  55 #include "locate_host.h"
  56 #include "room_ops.h"
  57 #include "file_ops.h"
  58 #include "policy.h"
  59 #include "control.h"
  60 #include "tools.h"
  61
  62 #ifndef HAVE_SNPRINTF
  63 #include "snprintf.h"
  64 #endif
  65
  66 struct CitContext *ContextList = NULL;
  67 char *unique_session_numbers;
  68 int ScheduledShutdown = 0;
  69 int do_defrag = 0;
  70 time_t server_startup_time;
  71
  72 /*
  73  * Various things that need to be initialized at startup
  74  */
  75 void master_startup(void) {
  76         struct timeval tv;
  77         struct ctdlroom qrbuf;
  78
  79         lprintf(9, "master_startup() started\n");
  80         time(&server_startup_time);
  81
  82         lprintf(7, "Opening databases\n");
  83         open_databases();
  84
  85         if (do_defrag) {
  86                 defrag_databases();
  87         }
  88
  89         check_ref_counts();
  90
  91         lprintf(7, "Creating base rooms (if necessary)\n");
  92         create_room(BASEROOM,           0, "", 0, 1, 0);
  93         create_room(AIDEROOM,           3, "", 0, 1, 0);
  94         create_room(SYSCONFIGROOM,      3, "", 0, 1, 0);
  95         create_room(config.c_twitroom,  0, "", 0, 1, 0);
  96
  97         /* The "Local System Configuration" room doesn't need to be visible */
  98         if (lgetroom(&qrbuf, SYSCONFIGROOM) == 0) {
  99                 qrbuf.QRflags2 |= QR2_SYSTEM;
 100                 lputroom(&qrbuf);
 101         }
 102
 103
 104         lprintf(7, "Seeding the pseudo-random number generator...\n");
 105         gettimeofday(&tv, NULL);
 106         srand(tv.tv_usec);
 107         lprintf(9, "master_startup() finished\n");
 108 }
 109
 110
 111
 112 /*
 113  * Cleanup routine to be called when the server is shutting down.
 114  * WARNING: It's no longer safe to call this function to force a shutdown.
 115  * Instead, set time_to_die = 1.
 116  */
 117 void master_cleanup(void) {
 118         struct CleanupFunctionHook *fcn;
 119
 120         /* Run any cleanup routines registered by loadable modules */
 121         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 122                 (*fcn->h_function_pointer)();
 123         }
 124
 125         /* Close databases */
 126         lprintf(7, "Closing databases\n");
 127         close_databases();
 128
 129         /* Do system-dependent stuff */
 130         sysdep_master_cleanup();
 131
 132         /* Now go away. */
 133         lprintf(3, "citserver: exiting.\n");
 134         fflush(stdout); fflush(stderr);
 135         exit(0);
 136 }
 137
 138
 139 /*
 140  * Free any per-session data allocated by modules or whatever
 141  */
 142 void deallocate_user_data(struct CitContext *con)
 143 {
 144         struct CtdlSessData *ptr;
 145
 146         begin_critical_section(S_SESSION_TABLE);
 147         while (con->FirstSessData != NULL) {
 148                 lprintf(9, "Deallocating user data symbol %ld\n",
 149                         con->FirstSessData->sym_id);
 150                 if (con->FirstSessData->sym_data != NULL)
 151                         phree(con->FirstSessData->sym_data);
 152                 ptr = con->FirstSessData->next;
 153                 phree(con->FirstSessData);
 154                 con->FirstSessData = ptr;
 155         }
 156         end_critical_section(S_SESSION_TABLE);
 157 }
 158
 159
 160
 161
 162 /*
 163  * Terminate a session and remove its context data structure.
 164  */
 165 void RemoveContext (struct CitContext *con)
 166 {
 167         struct CitContext *ptr = NULL;
 168         struct CitContext *ToFree = NULL;
 169
 170         lprintf(9, "RemoveContext() called\n");
 171         if (con==NULL) {
 172                 lprintf(5, "WARNING: RemoveContext() called with NULL!\n");
 173                 return;
 174         }
 175
 176         /* Remove the context from the global context list.  This needs
 177          * to get done FIRST to avoid concurrency problems.  It is *vitally*
 178          * important to keep num_sessions accurate!!
 179          */
 180         lprintf(7, "Removing context for session %d\n", con->cs_pid);
 181         begin_critical_section(S_SESSION_TABLE);
 182         if (ContextList == con) {
 183                 ToFree = ContextList;
 184                 ContextList = ContextList->next;
 185                 --num_sessions;
 186         }
 187         else {
 188                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 189                         if (ptr->next == con) {
 190                                 ToFree = ptr->next;
 191                                 ptr->next = ptr->next->next;
 192                                 --num_sessions;
 193                         }
 194                 }
 195         }
 196         end_critical_section(S_SESSION_TABLE);
 197
 198         if (ToFree == NULL) {
 199                 lprintf(9, "RemoveContext() found nothing to remove\n");
 200                 return;
 201         }
 202
 203         /* Run any cleanup routines registered by loadable modules.
 204          * Note 1: This must occur *before* deallocate_user_data() because the
 205          *         cleanup functions might touch dynamic session data.
 206          * Note 2: We have to "become_session()" because the cleanup functions
 207          *         might make references to "CC" assuming it's the right one.
 208          */
 209         become_session(con);
 210         PerformSessionHooks(EVT_STOP);
 211         become_session(NULL);
 212
 213         /* Now handle all of the administrivia. */
 214         lprintf(7, "Calling logout(%d)\n", con->cs_pid);
 215         logout(con);
 216
 217         unlink(con->temp);
 218         lprintf(3, "[%3d] Session ended.\n", con->cs_pid);
 219         syslog(LOG_NOTICE,"session %d: ended", con->cs_pid);
 220
 221         /* Deallocate any user-data attached to this session */
 222         deallocate_user_data(con);
 223
 224         /* If the client is still connected, blow 'em away. */
 225         lprintf(7, "Closing socket %d\n", con->client_socket);
 226         close(con->client_socket);
 227
 228         /* This is where we used to check for scheduled shutdowns. */
 229
 230         /* Free up the memory used by this context */
 231         phree(con);
 232
 233         lprintf(7, "Done with RemoveContext()\n");
 234 }
 235
 236
 237
 238 /*
 239  * Get a dynamic symbol number for per-session user data.
 240  * This API call should be made only ONCE per symbol per citserver run.
 241  */
 242 int CtdlGetDynamicSymbol()
 243 {
 244         static unsigned int next_symbol = SYM_MAX;
 245         return ++next_symbol;
 246 }
 247
 248
 249
 250 /*
 251  * Return a pointer to some generic per-session user data.
 252  * (This function returns NULL if the requested symbol is not allocated.)
 253  *
 254  * NOTE: we use critical sections for allocating and de-allocating these,
 255  *       but not for locating one.
 256  */
 257 void *CtdlGetUserData(unsigned long requested_sym)
 258 {
 259         struct CtdlSessData *ptr;
 260
 261         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)
 262                 if (ptr->sym_id == requested_sym)
 263                         return(ptr->sym_data);
 264
 265         lprintf(2, "ERROR! CtdlGetUserData(%ld) symbol not allocated\n",
 266                 requested_sym);
 267         return NULL;
 268 }
 269
 270
 271 /*
 272  * Allocate some generic per-session user data.
 273  */
 274 void CtdlAllocUserData(unsigned long requested_sym, size_t num_bytes)
 275 {
 276         struct CtdlSessData *ptr;
 277
 278         lprintf(9, "CtdlAllocUserData(%ld) called\n", requested_sym);
 279
 280         /* Fail silently if the symbol is already registered. */
 281         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)  {
 282                 if (ptr->sym_id == requested_sym) {
 283                         return;
 284                 }
 285         }
 286
 287         /* Grab us some memory!  Dem's good eatin' !!  */
 288         ptr = mallok(sizeof(struct CtdlSessData));
 289         ptr->sym_id = requested_sym;
 290         ptr->sym_data = mallok(num_bytes);
 291         memset(ptr->sym_data, 0, num_bytes);
 292
 293         begin_critical_section(S_SESSION_TABLE);
 294         ptr->next = CC->FirstSessData;
 295         CC->FirstSessData = ptr;
 296         end_critical_section(S_SESSION_TABLE);
 297
 298         lprintf(9, "CtdlAllocUserData(%ld) finished\n", requested_sym);
 299 }
 300
 301
 302 /*
 303  * Change the size of a buffer allocated with CtdlAllocUserData()
 304  */
 305 void CtdlReallocUserData(unsigned long requested_sym, size_t num_bytes)
 306 {
 307         struct CtdlSessData *ptr;
 308
 309         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)  {
 310                 if (ptr->sym_id == requested_sym) {
 311                         ptr->sym_data = reallok(ptr->sym_data, num_bytes);
 312                         return;
 313                 }
 314         }
 315
 316         lprintf(2, "CtdlReallocUserData() ERROR: symbol %ld not found!\n",
 317                 requested_sym);
 318 }
 319
 320
 321
 322
 323
 324
 325 /*
 326  * cmd_info()  -  tell the client about this server
 327  */
 328 void cmd_info(void) {
 329         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 330         cprintf("%d\n", CC->cs_pid);
 331         cprintf("%s\n", config.c_nodename);
 332         cprintf("%s\n", config.c_humannode);
 333         cprintf("%s\n", config.c_fqdn);
 334         cprintf("%s\n", CITADEL);
 335         cprintf("%d\n", REV_LEVEL);
 336         cprintf("%s\n", config.c_bbs_city);
 337         cprintf("%s\n", config.c_sysadm);
 338         cprintf("%d\n", SERVER_TYPE);
 339         cprintf("%s\n", config.c_moreprompt);
 340         cprintf("1\n"); /* 1 = yes, this system supports floors */
 341         cprintf("1\n"); /* 1 = we support the extended paging options */
 342         cprintf("%s\n", CC->cs_nonce);
 343         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 344         cprintf("000\n");
 345 }
 346
 347
 348 /*
 349  * returns an asterisk if there are any express messages waiting,
 350  * space otherwise.
 351  */
 352 char CtdlCheckExpress(void) {
 353         if (CC->FirstExpressMessage == NULL) {
 354                 return(' ');
 355         }
 356         else {
 357                 return('*');
 358         }
 359 }
 360
 361 void cmd_time(void)
 362 {
 363    time_t tv;
 364    struct tm *tmp;
 365
 366    tv = time(NULL);
 367    tmp = localtime(&tv);
 368
 369    /* timezone and daylight global variables are not portable. */
 370 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 371    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp->tm_gmtoff, tmp->tm_isdst);
 372 #else
 373    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp->tm_isdst);
 374 #endif
 375 }
 376
 377
 378 /*
 379  * Check originating host against the public_clients file.  This determines
 380  * whether the client is allowed to change the hostname for this session
 381  * (for example, to show the location of the user rather than the location
 382  * of the client).
 383  */
 384 int is_public_client(void)
 385 {
 386         char buf[SIZ];
 387         char addrbuf[SIZ];
 388         FILE *fp;
 389         int i;
 390         struct stat statbuf;
 391         static time_t pc_timestamp = 0;
 392         static char public_clients[SIZ];
 393
 394 #define PUBLIC_CLIENTS "./public_clients"
 395
 396         /*
 397          * Check the time stamp on the public_clients file.  If it's been
 398          * updated since the last time we were here (or if this is the first
 399          * time we've been through the loop), read its contents and learn
 400          * the IP addresses of the listed hosts.
 401          */
 402         if (stat(PUBLIC_CLIENTS, &statbuf) != 0) {
 403                 /* No public_clients file exists, so bail out */
 404                 lprintf(5, "Warning: '%s' does not exist\n", PUBLIC_CLIENTS);
 405                 return(0);
 406         }
 407
 408         if (statbuf.st_mtime > pc_timestamp) {
 409                 begin_critical_section(S_PUBLIC_CLIENTS);
 410                 lprintf(7, "Loading %s\n", PUBLIC_CLIENTS);
 411
 412                 strcpy(public_clients, "127.0.0.1");
 413                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 414                         strcat(public_clients, "|");
 415                         strcat(public_clients, addrbuf);
 416                 }
 417
 418                 fp = fopen("public_clients", "r");
 419                 if (fp != NULL) while (fgets(buf, sizeof buf, fp)!=NULL) {
 420                         for (i=0; i<strlen(buf); ++i) {
 421                                 if (buf[i] == '#') buf[i] = 0;
 422                         }
 423                         while (isspace((buf[strlen(buf)-1]))) {
 424                                 buf[strlen(buf)-1] = 0;
 425                         }
 426                         if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 427                                 if ((strlen(public_clients) +
 428                                    strlen(addrbuf) + 2)
 429                                    < sizeof(public_clients)) {
 430                                         strcat(public_clients, addrbuf);
 431                                 }
 432                         }
 433                 }
 434                 fclose(fp);
 435                 pc_timestamp = time(NULL);
 436                 end_critical_section(S_PUBLIC_CLIENTS);
 437         }
 438
 439         lprintf(9, "Checking whether %s is a local or public client\n",
 440                 CC->cs_addr);
 441         for (i=0; i<num_parms(public_clients); ++i) {
 442                 extract(addrbuf, public_clients, i);
 443                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 444                         lprintf(9, "... yes it is.\n");
 445                         return(1);
 446                 }
 447         }
 448
 449         /* No hits.  This is not a public client. */
 450         lprintf(9, "... no it isn't.\n");
 451         return(0);
 452 }
 453
 454
 455 /*
 456  * the client is identifying itself to the server
 457  */
 458 void cmd_iden(char *argbuf)
 459 {
 460         int dev_code;
 461         int cli_code;
 462         int rev_level;
 463         char desc[SIZ];
 464         char from_host[SIZ];
 465         struct in_addr addr;
 466         int do_lookup = 0;
 467
 468         if (num_parms(argbuf)<4) {
 469                 cprintf("%d usage error\n",ERROR);
 470                 return;
 471         }
 472
 473         dev_code = extract_int(argbuf,0);
 474         cli_code = extract_int(argbuf,1);
 475         rev_level = extract_int(argbuf,2);
 476         extract(desc,argbuf,3);
 477
 478         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 479         from_host[sizeof from_host - 1] = 0;
 480         if (num_parms(argbuf)>=5) extract(from_host,argbuf,4);
 481
 482         CC->cs_clientdev = dev_code;
 483         CC->cs_clienttyp = cli_code;
 484         CC->cs_clientver = rev_level;
 485         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 486         CC->cs_clientname[31] = 0;
 487
 488         if (strlen(from_host) > 0) {
 489                 if (CC->is_local_socket) do_lookup = 1;
 490                 else if (is_public_client()) do_lookup = 1;
 491         }
 492
 493         if (do_lookup) {
 494                 lprintf(9, "Looking up hostname '%s'\n", from_host);
 495                 if ((addr.s_addr = inet_addr(from_host)) != -1) {
 496                         locate_host(CC->cs_host, sizeof CC->cs_host,
 497                                 NULL, 0,
 498                                 &addr);
 499                 }
 500                 else {
 501                         safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 502                         CC->cs_host[sizeof CC->cs_host - 1] = 0;
 503                 }
 504         }
 505
 506         lprintf(7, "client %d/%d/%01d.%02d (%s)\n",
 507                 dev_code,
 508                 cli_code,
 509                 (rev_level / 100),
 510                 (rev_level % 100),
 511                 desc);
 512
 513         syslog(LOG_NOTICE,"session %d: client %d/%d/%01d.%02d (%s) from %s\n",
 514                 CC->cs_pid,
 515                 dev_code,
 516                 cli_code,
 517                 (rev_level / 100),
 518                 (rev_level % 100),
 519                 desc,
 520                 CC->cs_host);
 521         cprintf("%d Ok\n",CIT_OK);
 522 }
 523
 524
 525 /*
 526  * display system messages or help
 527  */
 528 void cmd_mesg(char *mname)
 529 {
 530         FILE *mfp;
 531         char targ[SIZ];
 532         char buf[SIZ];
 533         char buf2[SIZ];
 534         char *dirs[2];
 535
 536         extract(buf,mname,0);
 537
 538         dirs[0]=mallok(64);
 539         dirs[1]=mallok(64);
 540         strcpy(dirs[0],"messages");
 541         strcpy(dirs[1],"help");
 542         snprintf(buf2, sizeof buf2, "%s.%d.%d", buf, CC->cs_clientdev, CC->cs_clienttyp);
 543         mesg_locate(targ,sizeof targ,buf2,2,(const char **)dirs);
 544         if (strlen(targ) == 0) {
 545                 snprintf(buf2, sizeof buf2, "%s.%d", buf, CC->cs_clientdev);
 546                 mesg_locate(targ,sizeof targ,buf2,2,(const char **)dirs);
 547                 if (strlen(targ) == 0) {
 548                         mesg_locate(targ,sizeof targ,buf,2,(const char **)dirs);
 549                 }
 550         }
 551         phree(dirs[0]);
 552         phree(dirs[1]);
 553
 554         if (strlen(targ)==0) {
 555                 cprintf("%d '%s' not found.\n",ERROR,mname);
 556                 return;
 557         }
 558
 559         mfp = fopen(targ,"r");
 560         if (mfp==NULL) {
 561                 cprintf("%d Cannot open '%s': %s\n",
 562                         ERROR,targ,strerror(errno));
 563                 return;
 564         }
 565         cprintf("%d %s\n",LISTING_FOLLOWS,buf);
 566
 567         while (fgets(buf, (SIZ-1), mfp)!=NULL) {
 568                 buf[strlen(buf)-1] = 0;
 569                 do_help_subst(buf);
 570                 cprintf("%s\n",buf);
 571         }
 572
 573         fclose(mfp);
 574         cprintf("000\n");
 575 }
 576
 577
 578 /*
 579  * enter system messages or help
 580  */
 581 void cmd_emsg(char *mname)
 582 {
 583         FILE *mfp;
 584         char targ[SIZ];
 585         char buf[SIZ];
 586         char *dirs[2];
 587         int a;
 588
 589         if (CtdlAccessCheck(ac_aide)) return;
 590
 591         extract(buf,mname,0);
 592         for (a=0; a<strlen(buf); ++a) {         /* security measure */
 593                 if (buf[a] == '/') buf[a] = '.';
 594         }
 595
 596         dirs[0]=mallok(64);
 597         dirs[1]=mallok(64);
 598         strcpy(dirs[0],"messages");
 599         strcpy(dirs[1],"help");
 600         mesg_locate(targ,sizeof targ,buf,2,(const char**)dirs);
 601         phree(dirs[0]);
 602         phree(dirs[1]);
 603
 604         if (strlen(targ)==0) {
 605                 snprintf(targ, sizeof targ, "./help/%s", buf);
 606         }
 607
 608         mfp = fopen(targ,"w");
 609         if (mfp==NULL) {
 610                 cprintf("%d Cannot open '%s': %s\n",
 611                         ERROR,targ,strerror(errno));
 612                 return;
 613         }
 614         cprintf("%d %s\n", SEND_LISTING, targ);
 615
 616         while (client_gets(buf), strcmp(buf, "000")) {
 617                 fprintf(mfp, "%s\n", buf);
 618         }
 619
 620         fclose(mfp);
 621 }
 622
 623
 624 /* Don't show the names of private rooms unless the viewing
 625  * user also knows the rooms.
 626  */
 627 void GenerateRoomDisplay(char *real_room,
 628                         struct CitContext *viewed,
 629                         struct CitContext *viewer) {
 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                 if ( (CtdlRoomAccess(&viewed->room, &viewer->user)
 637                    & 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 (CC->user.axlevel >= 6) return(0);
 664         if (required_level >= ac_aide) {
 665                 cprintf("%d This command requires Aide access.\n",
 666                         ERROR+HIGHER_ACCESS_REQUIRED);
 667                 return(-1);
 668         }
 669
 670         if (is_room_aide()) return(0);
 671         if (required_level >= ac_room_aide) {
 672                 cprintf("%d This command requires Aide or Room Aide access.\n",
 673                         ERROR + HIGHER_ACCESS_REQUIRED);
 674                 return(-1);
 675         }
 676
 677         if (CC->logged_in) return(0);
 678         if (required_level >= ac_logged_in) {
 679                 cprintf("%d Not logged in.\n", ERROR+NOT_LOGGED_IN);
 680                 return(-1);
 681         }
 682
 683         /* shhh ... succeed quietly */
 684         return(0);
 685 }
 686
 687
 688
 689 /*
 690  * Terminate another running session
 691  */
 692 void cmd_term(char *cmdbuf)
 693 {
 694         int session_num;
 695         struct CitContext *ccptr;
 696         int found_it = 0;
 697         int allowed = 0;
 698
 699         session_num = extract_int(cmdbuf, 0);
 700         if (session_num == CC->cs_pid) {
 701                 cprintf("%d You can't kill your own session.\n", ERROR);
 702                 return;
 703         }
 704
 705         lprintf(9, "Locating session to kill\n");
 706         begin_critical_section(S_SESSION_TABLE);
 707         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 708                 if (session_num == ccptr->cs_pid) {
 709                         found_it = 1;
 710                         if ((ccptr->user.usernum == CC->user.usernum)
 711                            || (CC->user.axlevel >= 6)) {
 712                                 allowed = 1;
 713                                 ccptr->kill_me = 1;
 714                         }
 715                         else {
 716                                 allowed = 0;
 717                         }
 718                 }
 719         }
 720         end_critical_section(S_SESSION_TABLE);
 721
 722         if (found_it) {
 723                 if (allowed) {
 724                         cprintf("%d Session terminated.\n", CIT_OK);
 725                 }
 726                 else {
 727                         cprintf("%d You are not allowed to do that.\n",
 728                                 ERROR + HIGHER_ACCESS_REQUIRED);
 729                 }
 730         }
 731         else {
 732                 cprintf("%d No such session.\n", ERROR);
 733         }
 734 }
 735
 736
 737
 738
 739
 740 /*
 741  * get the paginator prompt
 742  */
 743 void cmd_more(void) {
 744         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 745 }
 746
 747 /*
 748  * echo
 749  */
 750 void cmd_echo(char *etext)
 751 {
 752         cprintf("%d %s\n", CIT_OK, etext);
 753 }
 754
 755
 756
 757 /*
 758  * identify as internal program
 759  */
 760 void cmd_ipgm(char *argbuf)
 761 {
 762         int secret;
 763
 764         secret = extract_int(argbuf, 0);
 765
 766         /* For security reasons, we do NOT allow this command to run
 767          * over the network.  Local sockets only.
 768          */
 769         if (!CC->is_local_socket) {
 770                 sleep(5);
 771                 cprintf("%d Authentication failed.\n",ERROR);
 772         }
 773         else if (secret == config.c_ipgm_secret) {
 774                 CC->internal_pgm = 1;
 775                 strcpy(CC->curr_user, "<internal program>");
 776                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 777                 cprintf("%d Authenticated as an internal program.\n",CIT_OK);
 778         }
 779         else {
 780                 sleep(5);
 781                 cprintf("%d Authentication failed.\n",ERROR);
 782                 lprintf(3, "Warning: ipgm authentication failed.\n");
 783                 CC->kill_me = 1;
 784         }
 785
 786         /* Now change the ipgm secret for the next round. */
 787         get_config();
 788         config.c_ipgm_secret = rand();
 789         put_config();
 790 }
 791
 792
 793 /*
 794  * Shut down the server
 795  */
 796 void cmd_down(void) {
 797
 798         if (CtdlAccessCheck(ac_aide)) return;
 799
 800         cprintf("%d Shutting down server.  Goodbye.\n", CIT_OK);
 801         time_to_die = 1;
 802 }
 803
 804 /*
 805  * Schedule or cancel a server shutdown
 806  */
 807 void cmd_scdn(char *argbuf)
 808 {
 809         int new_state;
 810
 811         if (CtdlAccessCheck(ac_aide)) return;
 812
 813         new_state = extract_int(argbuf, 0);
 814         if ((new_state == 0) || (new_state == 1)) {
 815                 ScheduledShutdown = new_state;
 816         }
 817         cprintf("%d %d\n", CIT_OK, ScheduledShutdown);
 818 }
 819
 820
 821 /*
 822  * Set or unset asynchronous protocol mode
 823  */
 824 void cmd_asyn(char *argbuf)
 825 {
 826         int new_state;
 827
 828         new_state = extract_int(argbuf, 0);
 829         if ((new_state == 0) || (new_state == 1)) {
 830                 CC->is_async = new_state;
 831         }
 832         cprintf("%d %d\n", CIT_OK, CC->is_async);
 833 }
 834
 835
 836 /*
 837  * Generate a "nonce" for APOP-style authentication.
 838  *
 839  * RFC 1725 et al specify a PID to be placed in front of the nonce.
 840  * Quoth BTX: That would be stupid.
 841  */
 842 void generate_nonce(struct CitContext *con) {
 843         struct timeval tv;
 844
 845         memset(con->cs_nonce, NONCE_SIZE, 0);
 846         gettimeofday(&tv, NULL);
 847         memset(con->cs_nonce, NONCE_SIZE, 0);
 848         snprintf(con->cs_nonce, NONCE_SIZE, "<%d%ld@%s>",
 849                 rand(), (long)tv.tv_usec, config.c_fqdn);
 850 }
 851
 852
 853
 854
 855 /*
 856  * Back-end function for starting a session
 857  */
 858 void begin_session(struct CitContext *con)
 859 {
 860         int len;        /* should be socklen_t but doesn't work on Macintosh */
 861         struct sockaddr_in sin;
 862
 863         /*
 864          * Initialize some variables specific to our context.
 865          */
 866         con->logged_in = 0;
 867         con->internal_pgm = 0;
 868         con->download_fp = NULL;
 869         con->upload_fp = NULL;
 870         con->FirstExpressMessage = NULL;
 871         time(&con->lastcmd);
 872         time(&con->lastidle);
 873         strcpy(con->lastcmdname, "    ");
 874         strcpy(con->cs_clientname, "(unknown)");
 875         strcpy(con->curr_user, NLI);
 876         strcpy(con->net_node,"");
 877         strcpy(con->fake_username, "");
 878         strcpy(con->fake_postname, "");
 879         strcpy(con->fake_hostname, "");
 880         strcpy(con->fake_roomname, "");
 881         generate_nonce(con);
 882         snprintf(con->temp, sizeof con->temp, tmpnam(NULL));
 883         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 884         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 885         con->cs_host[sizeof con->cs_host - 1] = 0;
 886         len = sizeof sin;
 887         if (!CC->is_local_socket) {
 888                 if (!getpeername(con->client_socket,
 889                    (struct sockaddr *) &sin, &len))
 890                         locate_host(con->cs_host, sizeof con->cs_host,
 891                                 con->cs_addr, sizeof con->cs_addr,
 892                                 &sin.sin_addr);
 893         }
 894         else {
 895                 strcpy(con->cs_host, "");
 896         }
 897         con->cs_flags = 0;
 898         con->upload_type = UPL_FILE;
 899         con->dl_is_net = 0;
 900         con->FirstSessData = NULL;
 901
 902         con->nologin = 0;
 903         if ((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions))
 904                 con->nologin = 1;
 905
 906         lprintf(3, "Session started.\n");
 907         syslog(LOG_NOTICE,"session %d: ended", con->cs_pid);
 908
 909         /* Run any session startup routines registered by loadable modules */
 910         PerformSessionHooks(EVT_START);
 911 }
 912
 913
 914 void citproto_begin_session() {
 915         if (CC->nologin==1) {
 916                 cprintf("%d %s: Too many users are already online "
 917                         "(maximum is %d)\n",
 918                         ERROR+MAX_SESSIONS_EXCEEDED,
 919                         config.c_nodename, config.c_maxsessions);
 920         }
 921         else {
 922                 cprintf("%d %s Citadel/UX server ready.\n",
 923                         CIT_OK, config.c_nodename);
 924         }
 925 }
 926
 927
 928
 929
 930 /*
 931  * This loop recognizes all server commands.
 932  */
 933 void do_command_loop(void) {
 934         char cmdbuf[SIZ];
 935
 936         time(&CC->lastcmd);
 937         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 938         if (client_gets(cmdbuf) < 1) {
 939                 lprintf(3, "Client socket is broken.  Ending session.\n");
 940                 CC->kill_me = 1;
 941                 return;
 942         }
 943         lprintf(5, "Citadel: %s\n", cmdbuf);
 944
 945         /*
 946          * Let other clients see the last command we executed, and
 947          * update the idle time, but not NOOP, QNOP, PEXP, or GEXP.
 948          */
 949         if ( (strncasecmp(cmdbuf, "NOOP", 4))
 950            && (strncasecmp(cmdbuf, "QNOP", 4))
 951            && (strncasecmp(cmdbuf, "PEXP", 4))
 952            && (strncasecmp(cmdbuf, "GEXP", 4)) ) {
 953                 strcpy(CC->lastcmdname, "    ");
 954                 safestrncpy(CC->lastcmdname, cmdbuf,
 955                         sizeof(CC->lastcmdname) );
 956                 time(&CC->lastidle);
 957         }
 958
 959         if ((strncasecmp(cmdbuf, "ENT0", 4))
 960            && (strncasecmp(cmdbuf, "MESG", 4))
 961            && (strncasecmp(cmdbuf, "MSGS", 4)))
 962         {
 963            CC->cs_flags &= ~CS_POSTING;
 964         }
 965
 966         if (!strncasecmp(cmdbuf,"NOOP",4)) {
 967                 cprintf("%d%cok\n",CIT_OK,CtdlCheckExpress());
 968         }
 969
 970         else if (!strncasecmp(cmdbuf,"QNOP",4)) {
 971                 /* do nothing, this command returns no response */
 972         }
 973
 974         else if (!strncasecmp(cmdbuf,"QUIT",4)) {
 975                 cprintf("%d Goodbye.\n",CIT_OK);
 976                 CC->kill_me = 1;
 977         }
 978
 979         else if (!strncasecmp(cmdbuf,"ASYN",4)) {
 980                 cmd_asyn(&cmdbuf[5]);
 981         }
 982
 983         else if (!strncasecmp(cmdbuf,"LOUT",4)) {
 984                 if (CC->logged_in) logout(CC);
 985                 cprintf("%d logged out.\n",CIT_OK);
 986         }
 987
 988         else if (!strncasecmp(cmdbuf,"USER",4)) {
 989                 cmd_user(&cmdbuf[5]);
 990         }
 991
 992         else if (!strncasecmp(cmdbuf,"PASS",4)) {
 993                 cmd_pass(&cmdbuf[5]);
 994         }
 995
 996         else if (!strncasecmp(cmdbuf,"NEWU",4)) {
 997                 cmd_newu(&cmdbuf[5]);
 998         }
 999
1000         else if (!strncasecmp(cmdbuf,"CREU",4)) {
1001                 cmd_creu(&cmdbuf[5]);
1002         }
1003
1004         else if (!strncasecmp(cmdbuf,"SETP",4)) {
1005                 cmd_setp(&cmdbuf[5]);
1006         }
1007
1008         else if (!strncasecmp(cmdbuf,"LRMS",4)) {
1009                 cmd_lrms(&cmdbuf[5]);
1010         }
1011
1012         else if (!strncasecmp(cmdbuf,"LKRA",4)) {
1013                 cmd_lkra(&cmdbuf[5]);
1014         }
1015
1016         else if (!strncasecmp(cmdbuf,"LKRN",4)) {
1017                 cmd_lkrn(&cmdbuf[5]);
1018         }
1019
1020         else if (!strncasecmp(cmdbuf,"LKRO",4)) {
1021                 cmd_lkro(&cmdbuf[5]);
1022         }
1023
1024         else if (!strncasecmp(cmdbuf,"LZRM",4)) {
1025                 cmd_lzrm(&cmdbuf[5]);
1026         }
1027
1028         else if (!strncasecmp(cmdbuf,"LPRM",4)) {
1029                 cmd_lprm(&cmdbuf[5]);
1030         }
1031
1032         else if (!strncasecmp(cmdbuf,"GETU",4)) {
1033                 cmd_getu();
1034         }
1035
1036         else if (!strncasecmp(cmdbuf,"SETU",4)) {
1037                 cmd_setu(&cmdbuf[5]);
1038         }
1039
1040         else if (!strncasecmp(cmdbuf,"GOTO",4)) {
1041                 cmd_goto(&cmdbuf[5]);
1042         }
1043
1044         else if (!strncasecmp(cmdbuf,"MSGS",4)) {
1045                 cmd_msgs(&cmdbuf[5]);
1046         }
1047
1048         else if (!strncasecmp(cmdbuf,"WHOK",4)) {
1049                 cmd_whok();
1050         }
1051
1052         else if (!strncasecmp(cmdbuf,"RDIR",4)) {
1053                 cmd_rdir();
1054         }
1055
1056         else if (!strncasecmp(cmdbuf,"MSG0",4)) {
1057                 cmd_msg0(&cmdbuf[5]);
1058         }
1059
1060         else if (!strncasecmp(cmdbuf,"MSG2",4)) {
1061                 cmd_msg2(&cmdbuf[5]);
1062         }
1063
1064         else if (!strncasecmp(cmdbuf,"MSG3",4)) {
1065                 cmd_msg3(&cmdbuf[5]);
1066         }
1067
1068         else if (!strncasecmp(cmdbuf,"MSG4",4)) {
1069                 cmd_msg4(&cmdbuf[5]);
1070         }
1071
1072         else if (!strncasecmp(cmdbuf,"MSGP",4)) {
1073                 cmd_msgp(&cmdbuf[5]);
1074         }
1075
1076         else if (!strncasecmp(cmdbuf,"OPNA",4)) {
1077                 cmd_opna(&cmdbuf[5]);
1078         }
1079
1080         else if (!strncasecmp(cmdbuf,"INFO",4)) {
1081                 cmd_info();
1082         }
1083
1084         else if (!strncasecmp(cmdbuf,"SLRP",4)) {
1085                 cmd_slrp(&cmdbuf[5]);
1086         }
1087
1088         else if (!strncasecmp(cmdbuf,"INVT",4)) {
1089                 cmd_invt_kick(&cmdbuf[5],1);
1090         }
1091
1092         else if (!strncasecmp(cmdbuf,"KICK",4)) {
1093                 cmd_invt_kick(&cmdbuf[5],0);
1094         }
1095
1096         else if (!strncasecmp(cmdbuf,"GETR",4)) {
1097                 cmd_getr();
1098         }
1099
1100         else if (!strncasecmp(cmdbuf,"SETR",4)) {
1101                 cmd_setr(&cmdbuf[5]);
1102         }
1103
1104         else if (!strncasecmp(cmdbuf,"GETA",4)) {
1105                 cmd_geta();
1106         }
1107
1108         else if (!strncasecmp(cmdbuf,"SETA",4)) {
1109                 cmd_seta(&cmdbuf[5]);
1110         }
1111
1112         else if (!strncasecmp(cmdbuf,"ENT0",4)) {
1113                 cmd_ent0(&cmdbuf[5]);
1114         }
1115
1116         else if (!strncasecmp(cmdbuf,"RINF",4)) {
1117                 cmd_rinf();
1118         }
1119
1120         else if (!strncasecmp(cmdbuf,"DELE",4)) {
1121                 cmd_dele(&cmdbuf[5]);
1122         }
1123
1124         else if (!strncasecmp(cmdbuf,"KILL",4)) {
1125                 cmd_kill(&cmdbuf[5]);
1126         }
1127
1128         else if (!strncasecmp(cmdbuf,"CRE8",4)) {
1129                 cmd_cre8(&cmdbuf[5]);
1130         }
1131
1132         else if (!strncasecmp(cmdbuf,"MOVE",4)) {
1133                 cmd_move(&cmdbuf[5]);
1134         }
1135
1136         else if (!strncasecmp(cmdbuf,"FORG",4)) {
1137                 cmd_forg();
1138         }
1139
1140         else if (!strncasecmp(cmdbuf,"MESG",4)) {
1141                 cmd_mesg(&cmdbuf[5]);
1142         }
1143
1144         else if (!strncasecmp(cmdbuf,"EMSG",4)) {
1145                 cmd_emsg(&cmdbuf[5]);
1146         }
1147
1148         else if (!strncasecmp(cmdbuf,"GNUR",4)) {
1149                 cmd_gnur();
1150         }
1151
1152         else if (!strncasecmp(cmdbuf,"VALI",4)) {
1153                 cmd_vali(&cmdbuf[5]);
1154         }
1155
1156         else if (!strncasecmp(cmdbuf,"EINF",4)) {
1157                 cmd_einf(&cmdbuf[5]);
1158         }
1159
1160         else if (!strncasecmp(cmdbuf,"LIST",4)) {
1161                 cmd_list();
1162         }
1163
1164         else if (!strncasecmp(cmdbuf,"CHEK",4)) {
1165                 cmd_chek();
1166         }
1167
1168         else if (!strncasecmp(cmdbuf,"DELF",4)) {
1169                 cmd_delf(&cmdbuf[5]);
1170         }
1171
1172         else if (!strncasecmp(cmdbuf,"MOVF",4)) {
1173                 cmd_movf(&cmdbuf[5]);
1174         }
1175
1176         else if (!strncasecmp(cmdbuf,"NETF",4)) {
1177                 cmd_netf(&cmdbuf[5]);
1178         }
1179
1180         else if (!strncasecmp(cmdbuf,"OPEN",4)) {
1181                 cmd_open(&cmdbuf[5]);
1182         }
1183
1184         else if (!strncasecmp(cmdbuf,"CLOS",4)) {
1185                 cmd_clos();
1186         }
1187
1188         else if (!strncasecmp(cmdbuf,"UOPN",4)) {
1189                 cmd_uopn(&cmdbuf[5]);
1190         }
1191
1192         else if (!strncasecmp(cmdbuf,"UCLS",4)) {
1193                 cmd_ucls(&cmdbuf[5]);
1194         }
1195
1196         else if (!strncasecmp(cmdbuf,"READ",4)) {
1197                 cmd_read(&cmdbuf[5]);
1198         }
1199
1200         else if (!strncasecmp(cmdbuf,"WRIT",4)) {
1201                 cmd_writ(&cmdbuf[5]);
1202         }
1203
1204         else if (!strncasecmp(cmdbuf,"QUSR",4)) {
1205                 cmd_qusr(&cmdbuf[5]);
1206         }
1207
1208         else if (!strncasecmp(cmdbuf,"ECHO",4)) {
1209                 cmd_echo(&cmdbuf[5]);
1210         }
1211
1212         else if (!strncasecmp(cmdbuf,"OIMG",4)) {
1213                 cmd_oimg(&cmdbuf[5]);
1214         }
1215
1216         else if (!strncasecmp(cmdbuf,"MORE",4)) {
1217                 cmd_more();
1218         }
1219
1220         else if (!strncasecmp(cmdbuf,"NDOP",4)) {
1221                 cmd_ndop(&cmdbuf[5]);
1222         }
1223
1224         else if (!strncasecmp(cmdbuf,"NUOP",4)) {
1225                 cmd_nuop(&cmdbuf[5]);
1226         }
1227
1228         else if (!strncasecmp(cmdbuf,"LFLR",4)) {
1229                 cmd_lflr();
1230         }
1231
1232         else if (!strncasecmp(cmdbuf,"CFLR",4)) {
1233                 cmd_cflr(&cmdbuf[5]);
1234         }
1235
1236         else if (!strncasecmp(cmdbuf,"KFLR",4)) {
1237                 cmd_kflr(&cmdbuf[5]);
1238         }
1239
1240         else if (!strncasecmp(cmdbuf,"EFLR",4)) {
1241                 cmd_eflr(&cmdbuf[5]);
1242         }
1243
1244         else if (!strncasecmp(cmdbuf,"IDEN",4)) {
1245                 cmd_iden(&cmdbuf[5]);
1246         }
1247
1248         else if (!strncasecmp(cmdbuf,"IPGM",4)) {
1249                 cmd_ipgm(&cmdbuf[5]);
1250         }
1251
1252         else if (!strncasecmp(cmdbuf,"TERM",4)) {
1253                 cmd_term(&cmdbuf[5]);
1254         }
1255
1256         else if (!strncasecmp(cmdbuf,"DOWN",4)) {
1257                 cmd_down();
1258         }
1259
1260         else if (!strncasecmp(cmdbuf,"SCDN",4)) {
1261                 cmd_scdn(&cmdbuf[5]);
1262         }
1263
1264         else if (!strncasecmp(cmdbuf, "UIMG", 4)) {
1265                 cmd_uimg(&cmdbuf[5]);
1266         }
1267
1268         else if (!strncasecmp(cmdbuf, "TIME", 4)) {
1269                 cmd_time();
1270         }
1271
1272         else if (!strncasecmp(cmdbuf, "AGUP", 4)) {
1273                 cmd_agup(&cmdbuf[5]);
1274         }
1275
1276         else if (!strncasecmp(cmdbuf, "ASUP", 4)) {
1277                 cmd_asup(&cmdbuf[5]);
1278         }
1279
1280         else if (!strncasecmp(cmdbuf, "GPEX", 4)) {
1281                 cmd_gpex(&cmdbuf[5]);
1282         }
1283
1284         else if (!strncasecmp(cmdbuf, "SPEX", 4)) {
1285                 cmd_spex(&cmdbuf[5]);
1286         }
1287
1288         else if (!strncasecmp(cmdbuf, "CONF", 4)) {
1289                 cmd_conf(&cmdbuf[5]);
1290         }
1291
1292         else if (!strncasecmp(cmdbuf, "SEEN", 4)) {
1293                 cmd_seen(&cmdbuf[5]);
1294         }
1295
1296         else if (!strncasecmp(cmdbuf, "GTSN", 4)) {
1297                 cmd_gtsn(&cmdbuf[5]);
1298         }
1299
1300         else if (!strncasecmp(cmdbuf, "VIEW", 4)) {
1301                 cmd_view(&cmdbuf[5]);
1302         }
1303
1304         else if (!strncasecmp(cmdbuf, "ISME", 4)) {
1305                 cmd_isme(&cmdbuf[5]);
1306         }
1307
1308 #ifdef DEBUG_MEMORY_LEAKS
1309         else if (!strncasecmp(cmdbuf, "LEAK", 4)) {
1310                 dump_tracked();
1311         }
1312 #endif
1313
1314         else if (!DLoader_Exec_Cmd(cmdbuf)) {
1315                 cprintf("%d Unrecognized or unsupported command.\n", ERROR);
1316                }
1317
1318         /* Run any after-each-command outines registered by modules */
1319         PerformSessionHooks(EVT_CMD);
1320 }