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         unsigned int seed;
  78         FILE *urandom;
  79         struct ctdlroom qrbuf;
  80
  81         lprintf(9, "master_startup() started\n");
  82         time(&server_startup_time);
  83
  84         lprintf(7, "Opening databases\n");
  85         open_databases();
  86
  87         if (do_defrag) {
  88                 defrag_databases();
  89         }
  90
  91         check_ref_counts();
  92
  93         lprintf(7, "Creating base rooms (if necessary)\n");
  94         create_room(BASEROOM,           0, "", 0, 1, 0);
  95         create_room(AIDEROOM,           3, "", 0, 1, 0);
  96         create_room(SYSCONFIGROOM,      3, "", 0, 1, 0);
  97         create_room(config.c_twitroom,  0, "", 0, 1, 0);
  98
  99         /* The "Local System Configuration" room doesn't need to be visible */
 100         if (lgetroom(&qrbuf, SYSCONFIGROOM) == 0) {
 101                 qrbuf.QRflags2 |= QR2_SYSTEM;
 102                 lputroom(&qrbuf);
 103         }
 104
 105         lprintf(7, "Seeding the pseudo-random number generator...\n");
 106         urandom = fopen("/dev/urandom", "r");
 107         if (urandom != NULL) {
 108                 fread(&seed, sizeof seed, 1, urandom);
 109                 fclose(urandom);
 110         }
 111         else {
 112                 gettimeofday(&tv, NULL);
 113                 seed = tv.tv_usec;
 114         }
 115         srandom(seed);
 116
 117         lprintf(7, "Initializing ipgm secret\n");
 118         get_config();
 119         config.c_ipgm_secret = rand();
 120         put_config();
 121
 122         lprintf(9, "master_startup() finished\n");
 123 }
 124
 125
 126 /*
 127  * Cleanup routine to be called when the server is shutting down.
 128  * WARNING: It's no longer safe to call this function to force a shutdown.
 129  * Instead, set time_to_die = 1.
 130  */
 131 void master_cleanup(void) {
 132         struct CleanupFunctionHook *fcn;
 133
 134         /* Run any cleanup routines registered by loadable modules */
 135         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 136                 (*fcn->h_function_pointer)();
 137         }
 138
 139         /* Close databases */
 140         lprintf(7, "Closing databases\n");
 141         close_databases();
 142
 143         /* Do system-dependent stuff */
 144         sysdep_master_cleanup();
 145
 146         /* Now go away. */
 147         lprintf(3, "citserver: exiting.\n");
 148         fflush(stdout); fflush(stderr);
 149         exit(0);
 150 }
 151
 152
 153 /*
 154  * Free any per-session data allocated by modules or whatever
 155  */
 156 void deallocate_user_data(struct CitContext *con)
 157 {
 158         struct CtdlSessData *ptr;
 159
 160         begin_critical_section(S_SESSION_TABLE);
 161         while (con->FirstSessData != NULL) {
 162                 lprintf(9, "Deallocating user data symbol %ld\n",
 163                         con->FirstSessData->sym_id);
 164                 if (con->FirstSessData->sym_data != NULL)
 165                         phree(con->FirstSessData->sym_data);
 166                 ptr = con->FirstSessData->next;
 167                 phree(con->FirstSessData);
 168                 con->FirstSessData = ptr;
 169         }
 170         end_critical_section(S_SESSION_TABLE);
 171 }
 172
 173
 174
 175
 176 /*
 177  * Terminate a session and remove its context data structure.
 178  */
 179 void RemoveContext (struct CitContext *con)
 180 {
 181         struct CitContext *ptr = NULL;
 182         struct CitContext *ToFree = NULL;
 183
 184         lprintf(9, "RemoveContext() called\n");
 185         if (con==NULL) {
 186                 lprintf(5, "WARNING: RemoveContext() called with NULL!\n");
 187                 return;
 188         }
 189
 190         /* Remove the context from the global context list.  This needs
 191          * to get done FIRST to avoid concurrency problems.  It is *vitally*
 192          * important to keep num_sessions accurate!!
 193          */
 194         lprintf(7, "Removing context for session %d\n", con->cs_pid);
 195         begin_critical_section(S_SESSION_TABLE);
 196         if (ContextList == con) {
 197                 ToFree = ContextList;
 198                 ContextList = ContextList->next;
 199                 --num_sessions;
 200         }
 201         else {
 202                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 203                         if (ptr->next == con) {
 204                                 ToFree = ptr->next;
 205                                 ptr->next = ptr->next->next;
 206                                 --num_sessions;
 207                         }
 208                 }
 209         }
 210         end_critical_section(S_SESSION_TABLE);
 211
 212         if (ToFree == NULL) {
 213                 lprintf(9, "RemoveContext() found nothing to remove\n");
 214                 return;
 215         }
 216
 217         /* Run any cleanup routines registered by loadable modules.
 218          * Note 1: This must occur *before* deallocate_user_data() because the
 219          *         cleanup functions might touch dynamic session data.
 220          * Note 2: We have to "become_session()" because the cleanup functions
 221          *         might make references to "CC" assuming it's the right one.
 222          */
 223         become_session(con);
 224         PerformSessionHooks(EVT_STOP);
 225         become_session(NULL);
 226
 227         /* Now handle all of the administrivia. */
 228         lprintf(7, "Calling logout(%d)\n", con->cs_pid);
 229         logout(con);
 230
 231         unlink(con->temp);
 232         lprintf(3, "[%3d] Session ended.\n", con->cs_pid);
 233         syslog(LOG_NOTICE,"session %d: ended", con->cs_pid);
 234
 235         /* Deallocate any user-data attached to this session */
 236         deallocate_user_data(con);
 237
 238         /* If the client is still connected, blow 'em away. */
 239         lprintf(7, "Closing socket %d\n", con->client_socket);
 240         close(con->client_socket);
 241
 242         /* This is where we used to check for scheduled shutdowns. */
 243
 244         /* Free up the memory used by this context */
 245         phree(con);
 246
 247         lprintf(7, "Done with RemoveContext()\n");
 248 }
 249
 250
 251
 252 /*
 253  * Get a dynamic symbol number for per-session user data.
 254  * This API call should be made only ONCE per symbol per citserver run.
 255  */
 256 int CtdlGetDynamicSymbol()
 257 {
 258         static unsigned int next_symbol = SYM_MAX;
 259         return ++next_symbol;
 260 }
 261
 262
 263
 264 /*
 265  * Return a pointer to some generic per-session user data.
 266  * (This function returns NULL if the requested symbol is not allocated.)
 267  *
 268  * NOTE: we use critical sections for allocating and de-allocating these,
 269  *       but not for locating one.
 270  */
 271 void *CtdlGetUserData(unsigned long requested_sym)
 272 {
 273         struct CtdlSessData *ptr;
 274
 275         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)
 276                 if (ptr->sym_id == requested_sym)
 277                         return(ptr->sym_data);
 278
 279         lprintf(2, "ERROR! CtdlGetUserData(%ld) symbol not allocated\n",
 280                 requested_sym);
 281         return NULL;
 282 }
 283
 284
 285 /*
 286  * Allocate some generic per-session user data.
 287  */
 288 void CtdlAllocUserData(unsigned long requested_sym, size_t num_bytes)
 289 {
 290         struct CtdlSessData *ptr;
 291
 292         lprintf(9, "CtdlAllocUserData(%ld) called\n", requested_sym);
 293
 294         /* Fail silently if the symbol is already registered. */
 295         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)  {
 296                 if (ptr->sym_id == requested_sym) {
 297                         return;
 298                 }
 299         }
 300
 301         /* Grab us some memory!  Dem's good eatin' !!  */
 302         ptr = mallok(sizeof(struct CtdlSessData));
 303         ptr->sym_id = requested_sym;
 304         ptr->sym_data = mallok(num_bytes);
 305         memset(ptr->sym_data, 0, num_bytes);
 306
 307         begin_critical_section(S_SESSION_TABLE);
 308         ptr->next = CC->FirstSessData;
 309         CC->FirstSessData = ptr;
 310         end_critical_section(S_SESSION_TABLE);
 311
 312         lprintf(9, "CtdlAllocUserData(%ld) finished\n", requested_sym);
 313 }
 314
 315
 316 /*
 317  * Change the size of a buffer allocated with CtdlAllocUserData()
 318  */
 319 void CtdlReallocUserData(unsigned long requested_sym, size_t num_bytes)
 320 {
 321         struct CtdlSessData *ptr;
 322
 323         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)  {
 324                 if (ptr->sym_id == requested_sym) {
 325                         ptr->sym_data = reallok(ptr->sym_data, num_bytes);
 326                         return;
 327                 }
 328         }
 329
 330         lprintf(2, "CtdlReallocUserData() ERROR: symbol %ld not found!\n",
 331                 requested_sym);
 332 }
 333
 334
 335
 336
 337
 338
 339 /*
 340  * cmd_info()  -  tell the client about this server
 341  */
 342 void cmd_info(void) {
 343         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 344         cprintf("%d\n", CC->cs_pid);
 345         cprintf("%s\n", config.c_nodename);
 346         cprintf("%s\n", config.c_humannode);
 347         cprintf("%s\n", config.c_fqdn);
 348         cprintf("%s\n", CITADEL);
 349         cprintf("%d\n", REV_LEVEL);
 350         cprintf("%s\n", config.c_bbs_city);
 351         cprintf("%s\n", config.c_sysadm);
 352         cprintf("%d\n", SERVER_TYPE);
 353         cprintf("%s\n", config.c_moreprompt);
 354         cprintf("1\n"); /* 1 = yes, this system supports floors */
 355         cprintf("1\n"); /* 1 = we support the extended paging options */
 356         cprintf("%s\n", CC->cs_nonce);
 357         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 358         cprintf("000\n");
 359 }
 360
 361
 362 /*
 363  * returns an asterisk if there are any express messages waiting,
 364  * space otherwise.
 365  */
 366 char CtdlCheckExpress(void) {
 367         if (CC->FirstExpressMessage == NULL) {
 368                 return(' ');
 369         }
 370         else {
 371                 return('*');
 372         }
 373 }
 374
 375 void cmd_time(void)
 376 {
 377    time_t tv;
 378    struct tm *tmp;
 379
 380    tv = time(NULL);
 381    tmp = localtime(&tv);
 382
 383    /* timezone and daylight global variables are not portable. */
 384 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 385    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp->tm_gmtoff, tmp->tm_isdst);
 386 #else
 387    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp->tm_isdst);
 388 #endif
 389 }
 390
 391
 392 /*
 393  * Check originating host against the public_clients file.  This determines
 394  * whether the client is allowed to change the hostname for this session
 395  * (for example, to show the location of the user rather than the location
 396  * of the client).
 397  */
 398 int is_public_client(void)
 399 {
 400         char buf[SIZ];
 401         char addrbuf[SIZ];
 402         FILE *fp;
 403         int i;
 404         struct stat statbuf;
 405         static time_t pc_timestamp = 0;
 406         static char public_clients[SIZ];
 407
 408 #define PUBLIC_CLIENTS "./public_clients"
 409
 410         /*
 411          * Check the time stamp on the public_clients file.  If it's been
 412          * updated since the last time we were here (or if this is the first
 413          * time we've been through the loop), read its contents and learn
 414          * the IP addresses of the listed hosts.
 415          */
 416         if (stat(PUBLIC_CLIENTS, &statbuf) != 0) {
 417                 /* No public_clients file exists, so bail out */
 418                 lprintf(5, "Warning: '%s' does not exist\n", PUBLIC_CLIENTS);
 419                 return(0);
 420         }
 421
 422         if (statbuf.st_mtime > pc_timestamp) {
 423                 begin_critical_section(S_PUBLIC_CLIENTS);
 424                 lprintf(7, "Loading %s\n", PUBLIC_CLIENTS);
 425
 426                 strcpy(public_clients, "127.0.0.1");
 427                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 428                         strcat(public_clients, "|");
 429                         strcat(public_clients, addrbuf);
 430                 }
 431
 432                 fp = fopen("public_clients", "r");
 433                 if (fp != NULL) while (fgets(buf, sizeof buf, fp)!=NULL) {
 434                         for (i=0; i<strlen(buf); ++i) {
 435                                 if (buf[i] == '#') buf[i] = 0;
 436                         }
 437                         while (isspace((buf[strlen(buf)-1]))) {
 438                                 buf[strlen(buf)-1] = 0;
 439                         }
 440                         if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 441                                 if ((strlen(public_clients) +
 442                                    strlen(addrbuf) + 2)
 443                                    < sizeof(public_clients)) {
 444                                         strcat(public_clients, addrbuf);
 445                                 }
 446                         }
 447                 }
 448                 fclose(fp);
 449                 pc_timestamp = time(NULL);
 450                 end_critical_section(S_PUBLIC_CLIENTS);
 451         }
 452
 453         lprintf(9, "Checking whether %s is a local or public client\n",
 454                 CC->cs_addr);
 455         for (i=0; i<num_parms(public_clients); ++i) {
 456                 extract(addrbuf, public_clients, i);
 457                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 458                         lprintf(9, "... yes it is.\n");
 459                         return(1);
 460                 }
 461         }
 462
 463         /* No hits.  This is not a public client. */
 464         lprintf(9, "... no it isn't.\n");
 465         return(0);
 466 }
 467
 468
 469 /*
 470  * the client is identifying itself to the server
 471  */
 472 void cmd_iden(char *argbuf)
 473 {
 474         int dev_code;
 475         int cli_code;
 476         int rev_level;
 477         char desc[SIZ];
 478         char from_host[SIZ];
 479         struct in_addr addr;
 480         int do_lookup = 0;
 481
 482         if (num_parms(argbuf)<4) {
 483                 cprintf("%d usage error\n",ERROR);
 484                 return;
 485         }
 486
 487         dev_code = extract_int(argbuf,0);
 488         cli_code = extract_int(argbuf,1);
 489         rev_level = extract_int(argbuf,2);
 490         extract(desc,argbuf,3);
 491
 492         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 493         from_host[sizeof from_host - 1] = 0;
 494         if (num_parms(argbuf)>=5) extract(from_host,argbuf,4);
 495
 496         CC->cs_clientdev = dev_code;
 497         CC->cs_clienttyp = cli_code;
 498         CC->cs_clientver = rev_level;
 499         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 500         CC->cs_clientname[31] = 0;
 501
 502         if (strlen(from_host) > 0) {
 503                 if (CC->is_local_socket) do_lookup = 1;
 504                 else if (is_public_client()) do_lookup = 1;
 505         }
 506
 507         if (do_lookup) {
 508                 lprintf(9, "Looking up hostname '%s'\n", from_host);
 509                 if ((addr.s_addr = inet_addr(from_host)) != -1) {
 510                         locate_host(CC->cs_host, sizeof CC->cs_host,
 511                                 NULL, 0,
 512                                 &addr);
 513                 }
 514                 else {
 515                         safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 516                         CC->cs_host[sizeof CC->cs_host - 1] = 0;
 517                 }
 518         }
 519
 520         lprintf(7, "client %d/%d/%01d.%02d (%s)\n",
 521                 dev_code,
 522                 cli_code,
 523                 (rev_level / 100),
 524                 (rev_level % 100),
 525                 desc);
 526
 527         syslog(LOG_NOTICE,"session %d: client %d/%d/%01d.%02d (%s) from %s\n",
 528                 CC->cs_pid,
 529                 dev_code,
 530                 cli_code,
 531                 (rev_level / 100),
 532                 (rev_level % 100),
 533                 desc,
 534                 CC->cs_host);
 535         cprintf("%d Ok\n",CIT_OK);
 536 }
 537
 538
 539 /*
 540  * display system messages or help
 541  */
 542 void cmd_mesg(char *mname)
 543 {
 544         FILE *mfp;
 545         char targ[SIZ];
 546         char buf[SIZ];
 547         char buf2[SIZ];
 548         char *dirs[2];
 549
 550         extract(buf,mname,0);
 551
 552         dirs[0]=mallok(64);
 553         dirs[1]=mallok(64);
 554         strcpy(dirs[0],"messages");
 555         strcpy(dirs[1],"help");
 556         snprintf(buf2, sizeof buf2, "%s.%d.%d", buf, CC->cs_clientdev, CC->cs_clienttyp);
 557         mesg_locate(targ,sizeof targ,buf2,2,(const char **)dirs);
 558         if (strlen(targ) == 0) {
 559                 snprintf(buf2, sizeof buf2, "%s.%d", buf, CC->cs_clientdev);
 560                 mesg_locate(targ,sizeof targ,buf2,2,(const char **)dirs);
 561                 if (strlen(targ) == 0) {
 562                         mesg_locate(targ,sizeof targ,buf,2,(const char **)dirs);
 563                 }
 564         }
 565         phree(dirs[0]);
 566         phree(dirs[1]);
 567
 568         if (strlen(targ)==0) {
 569                 cprintf("%d '%s' not found.\n",ERROR,mname);
 570                 return;
 571         }
 572
 573         mfp = fopen(targ,"r");
 574         if (mfp==NULL) {
 575                 cprintf("%d Cannot open '%s': %s\n",
 576                         ERROR,targ,strerror(errno));
 577                 return;
 578         }
 579         cprintf("%d %s\n",LISTING_FOLLOWS,buf);
 580
 581         while (fgets(buf, (SIZ-1), mfp)!=NULL) {
 582                 buf[strlen(buf)-1] = 0;
 583                 do_help_subst(buf);
 584                 cprintf("%s\n",buf);
 585         }
 586
 587         fclose(mfp);
 588         cprintf("000\n");
 589 }
 590
 591
 592 /*
 593  * enter system messages or help
 594  */
 595 void cmd_emsg(char *mname)
 596 {
 597         FILE *mfp;
 598         char targ[SIZ];
 599         char buf[SIZ];
 600         char *dirs[2];
 601         int a;
 602
 603         if (CtdlAccessCheck(ac_aide)) return;
 604
 605         extract(buf,mname,0);
 606         for (a=0; a<strlen(buf); ++a) {         /* security measure */
 607                 if (buf[a] == '/') buf[a] = '.';
 608         }
 609
 610         dirs[0]=mallok(64);
 611         dirs[1]=mallok(64);
 612         strcpy(dirs[0],"messages");
 613         strcpy(dirs[1],"help");
 614         mesg_locate(targ,sizeof targ,buf,2,(const char**)dirs);
 615         phree(dirs[0]);
 616         phree(dirs[1]);
 617
 618         if (strlen(targ)==0) {
 619                 snprintf(targ, sizeof targ, "./help/%s", buf);
 620         }
 621
 622         mfp = fopen(targ,"w");
 623         if (mfp==NULL) {
 624                 cprintf("%d Cannot open '%s': %s\n",
 625                         ERROR,targ,strerror(errno));
 626                 return;
 627         }
 628         cprintf("%d %s\n", SEND_LISTING, targ);
 629
 630         while (client_gets(buf), strcmp(buf, "000")) {
 631                 fprintf(mfp, "%s\n", buf);
 632         }
 633
 634         fclose(mfp);
 635 }
 636
 637
 638 /* Don't show the names of private rooms unless the viewing
 639  * user also knows the rooms.
 640  */
 641 void GenerateRoomDisplay(char *real_room,
 642                         struct CitContext *viewed,
 643                         struct CitContext *viewer) {
 644
 645         strcpy(real_room, viewed->room.QRname);
 646         if (viewed->room.QRflags & QR_MAILBOX) {
 647                 strcpy(real_room, &real_room[11]);
 648         }
 649         if (viewed->room.QRflags & QR_PRIVATE) {
 650                 if ( (CtdlRoomAccess(&viewed->room, &viewer->user)
 651                    & UA_KNOWN) == 0) {
 652                         strcpy(real_room, "<private room>");
 653                 }
 654         }
 655
 656         if (viewed->cs_flags & CS_CHAT) {
 657                 while (strlen(real_room) < 14)
 658                         strcat(real_room, " ");
 659
 660                 strcpy(&real_room[14], "<chat>");
 661         }
 662
 663 }
 664
 665 /*
 666  * Convenience function.
 667  */
 668 int CtdlAccessCheck(int required_level) {
 669
 670         if (CC->internal_pgm) return(0);
 671         if (required_level >= ac_internal) {
 672                 cprintf("%d This is not a user-level command.\n",
 673                         ERROR+HIGHER_ACCESS_REQUIRED);
 674                 return(-1);
 675         }
 676
 677         if (CC->user.axlevel >= 6) return(0);
 678         if (required_level >= ac_aide) {
 679                 cprintf("%d This command requires Aide access.\n",
 680                         ERROR+HIGHER_ACCESS_REQUIRED);
 681                 return(-1);
 682         }
 683
 684         if (is_room_aide()) return(0);
 685         if (required_level >= ac_room_aide) {
 686                 cprintf("%d This command requires Aide or Room Aide access.\n",
 687                         ERROR + HIGHER_ACCESS_REQUIRED);
 688                 return(-1);
 689         }
 690
 691         if (CC->logged_in) return(0);
 692         if (required_level >= ac_logged_in) {
 693                 cprintf("%d Not logged in.\n", ERROR+NOT_LOGGED_IN);
 694                 return(-1);
 695         }
 696
 697         /* shhh ... succeed quietly */
 698         return(0);
 699 }
 700
 701
 702
 703 /*
 704  * Terminate another running session
 705  */
 706 void cmd_term(char *cmdbuf)
 707 {
 708         int session_num;
 709         struct CitContext *ccptr;
 710         int found_it = 0;
 711         int allowed = 0;
 712
 713         session_num = extract_int(cmdbuf, 0);
 714         if (session_num == CC->cs_pid) {
 715                 cprintf("%d You can't kill your own session.\n", ERROR);
 716                 return;
 717         }
 718
 719         lprintf(9, "Locating session to kill\n");
 720         begin_critical_section(S_SESSION_TABLE);
 721         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 722                 if (session_num == ccptr->cs_pid) {
 723                         found_it = 1;
 724                         if ((ccptr->user.usernum == CC->user.usernum)
 725                            || (CC->user.axlevel >= 6)) {
 726                                 allowed = 1;
 727                                 ccptr->kill_me = 1;
 728                         }
 729                         else {
 730                                 allowed = 0;
 731                         }
 732                 }
 733         }
 734         end_critical_section(S_SESSION_TABLE);
 735
 736         if (found_it) {
 737                 if (allowed) {
 738                         cprintf("%d Session terminated.\n", CIT_OK);
 739                 }
 740                 else {
 741                         cprintf("%d You are not allowed to do that.\n",
 742                                 ERROR + HIGHER_ACCESS_REQUIRED);
 743                 }
 744         }
 745         else {
 746                 cprintf("%d No such session.\n", ERROR);
 747         }
 748 }
 749
 750
 751
 752
 753
 754 /*
 755  * get the paginator prompt
 756  */
 757 void cmd_more(void) {
 758         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 759 }
 760
 761 /*
 762  * echo
 763  */
 764 void cmd_echo(char *etext)
 765 {
 766         cprintf("%d %s\n", CIT_OK, etext);
 767 }
 768
 769
 770
 771 /*
 772  * identify as internal program
 773  */
 774 void cmd_ipgm(char *argbuf)
 775 {
 776         int secret;
 777
 778         secret = extract_int(argbuf, 0);
 779
 780         /* For security reasons, we do NOT allow this command to run
 781          * over the network.  Local sockets only.
 782          */
 783         if (!CC->is_local_socket) {
 784                 sleep(5);
 785                 cprintf("%d Authentication failed.\n",ERROR);
 786         }
 787         else if (secret == config.c_ipgm_secret) {
 788                 CC->internal_pgm = 1;
 789                 strcpy(CC->curr_user, "<internal program>");
 790                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 791                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
 792         }
 793         else {
 794                 sleep(5);
 795                 cprintf("%d Authentication failed.\n",ERROR);
 796                 lprintf(3, "Warning: ipgm authentication failed.\n");
 797                 CC->kill_me = 1;
 798         }
 799
 800         /* Now change the ipgm secret for the next round. */
 801         get_config();
 802         config.c_ipgm_secret = rand();
 803         put_config();
 804 }
 805
 806
 807 /*
 808  * Shut down the server
 809  */
 810 void cmd_down(void) {
 811
 812         if (CtdlAccessCheck(ac_aide)) return;
 813
 814         cprintf("%d Shutting down server.  Goodbye.\n", CIT_OK);
 815         time_to_die = 1;
 816 }
 817
 818 /*
 819  * Schedule or cancel a server shutdown
 820  */
 821 void cmd_scdn(char *argbuf)
 822 {
 823         int new_state;
 824
 825         if (CtdlAccessCheck(ac_aide)) return;
 826
 827         new_state = extract_int(argbuf, 0);
 828         if ((new_state == 0) || (new_state == 1)) {
 829                 ScheduledShutdown = new_state;
 830         }
 831         cprintf("%d %d\n", CIT_OK, ScheduledShutdown);
 832 }
 833
 834
 835 /*
 836  * Set or unset asynchronous protocol mode
 837  */
 838 void cmd_asyn(char *argbuf)
 839 {
 840         int new_state;
 841
 842         new_state = extract_int(argbuf, 0);
 843         if ((new_state == 0) || (new_state == 1)) {
 844                 CC->is_async = new_state;
 845         }
 846         cprintf("%d %d\n", CIT_OK, CC->is_async);
 847 }
 848
 849
 850 /*
 851  * Generate a "nonce" for APOP-style authentication.
 852  *
 853  * RFC 1725 et al specify a PID to be placed in front of the nonce.
 854  * Quoth BTX: That would be stupid.
 855  */
 856 void generate_nonce(struct CitContext *con) {
 857         struct timeval tv;
 858
 859         memset(con->cs_nonce, NONCE_SIZE, 0);
 860         gettimeofday(&tv, NULL);
 861         memset(con->cs_nonce, NONCE_SIZE, 0);
 862         snprintf(con->cs_nonce, NONCE_SIZE, "<%d%ld@%s>",
 863                 rand(), (long)tv.tv_usec, config.c_fqdn);
 864 }
 865
 866
 867
 868
 869 /*
 870  * Back-end function for starting a session
 871  */
 872 void begin_session(struct CitContext *con)
 873 {
 874         int len;        /* should be socklen_t but doesn't work on Macintosh */
 875         struct sockaddr_in sin;
 876
 877         /*
 878          * Initialize some variables specific to our context.
 879          */
 880         con->logged_in = 0;
 881         con->internal_pgm = 0;
 882         con->download_fp = NULL;
 883         con->upload_fp = NULL;
 884         con->FirstExpressMessage = NULL;
 885         time(&con->lastcmd);
 886         time(&con->lastidle);
 887         strcpy(con->lastcmdname, "    ");
 888         strcpy(con->cs_clientname, "(unknown)");
 889         strcpy(con->curr_user, NLI);
 890         strcpy(con->net_node,"");
 891         strcpy(con->fake_username, "");
 892         strcpy(con->fake_postname, "");
 893         strcpy(con->fake_hostname, "");
 894         strcpy(con->fake_roomname, "");
 895         generate_nonce(con);
 896         snprintf(con->temp, sizeof con->temp, tmpnam(NULL));
 897         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 898         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 899         con->cs_host[sizeof con->cs_host - 1] = 0;
 900         len = sizeof sin;
 901         if (!CC->is_local_socket) {
 902                 if (!getpeername(con->client_socket,
 903                    (struct sockaddr *) &sin, &len))
 904                         locate_host(con->cs_host, sizeof con->cs_host,
 905                                 con->cs_addr, sizeof con->cs_addr,
 906                                 &sin.sin_addr);
 907         }
 908         else {
 909                 strcpy(con->cs_host, "");
 910         }
 911         con->cs_flags = 0;
 912         con->upload_type = UPL_FILE;
 913         con->dl_is_net = 0;
 914         con->FirstSessData = NULL;
 915
 916         con->nologin = 0;
 917         if ((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions))
 918                 con->nologin = 1;
 919
 920         lprintf(3, "Session started.\n");
 921         syslog(LOG_NOTICE,"session %d: ended", con->cs_pid);
 922
 923         /* Run any session startup routines registered by loadable modules */
 924         PerformSessionHooks(EVT_START);
 925 }
 926
 927
 928 void citproto_begin_session() {
 929         if (CC->nologin==1) {
 930                 cprintf("%d %s: Too many users are already online "
 931                         "(maximum is %d)\n",
 932                         ERROR+MAX_SESSIONS_EXCEEDED,
 933                         config.c_nodename, config.c_maxsessions);
 934         }
 935         else {
 936                 cprintf("%d %s Citadel/UX server ready.\n",
 937                         CIT_OK, config.c_nodename);
 938         }
 939 }
 940
 941
 942
 943
 944 /*
 945  * This loop recognizes all server commands.
 946  */
 947 void do_command_loop(void) {
 948         char cmdbuf[SIZ];
 949
 950         time(&CC->lastcmd);
 951         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 952         if (client_gets(cmdbuf) < 1) {
 953                 lprintf(3, "Client socket is broken.  Ending session.\n");
 954                 CC->kill_me = 1;
 955                 return;
 956         }
 957         lprintf(5, "Citadel: %s\n", cmdbuf);
 958
 959         /*
 960          * Let other clients see the last command we executed, and
 961          * update the idle time, but not NOOP, QNOP, PEXP, or GEXP.
 962          */
 963         if ( (strncasecmp(cmdbuf, "NOOP", 4))
 964            && (strncasecmp(cmdbuf, "QNOP", 4))
 965            && (strncasecmp(cmdbuf, "PEXP", 4))
 966            && (strncasecmp(cmdbuf, "GEXP", 4)) ) {
 967                 strcpy(CC->lastcmdname, "    ");
 968                 safestrncpy(CC->lastcmdname, cmdbuf,
 969                         sizeof(CC->lastcmdname) );
 970                 time(&CC->lastidle);
 971         }
 972
 973         if ((strncasecmp(cmdbuf, "ENT0", 4))
 974            && (strncasecmp(cmdbuf, "MESG", 4))
 975            && (strncasecmp(cmdbuf, "MSGS", 4)))
 976         {
 977            CC->cs_flags &= ~CS_POSTING;
 978         }
 979
 980         if (!strncasecmp(cmdbuf,"NOOP",4)) {
 981                 cprintf("%d%cok\n",CIT_OK,CtdlCheckExpress());
 982         }
 983
 984         else if (!strncasecmp(cmdbuf,"QNOP",4)) {
 985                 /* do nothing, this command returns no response */
 986         }
 987
 988         else if (!strncasecmp(cmdbuf,"QUIT",4)) {
 989                 cprintf("%d Goodbye.\n",CIT_OK);
 990                 CC->kill_me = 1;
 991         }
 992
 993         else if (!strncasecmp(cmdbuf,"ASYN",4)) {
 994                 cmd_asyn(&cmdbuf[5]);
 995         }
 996
 997         else if (!strncasecmp(cmdbuf,"LOUT",4)) {
 998                 if (CC->logged_in) logout(CC);
 999                 cprintf("%d logged out.\n",CIT_OK);
1000         }
1001
1002         else if (!strncasecmp(cmdbuf,"USER",4)) {
1003                 cmd_user(&cmdbuf[5]);
1004         }
1005
1006         else if (!strncasecmp(cmdbuf,"PASS",4)) {
1007                 cmd_pass(&cmdbuf[5]);
1008         }
1009
1010         else if (!strncasecmp(cmdbuf,"NEWU",4)) {
1011                 cmd_newu(&cmdbuf[5]);
1012         }
1013
1014         else if (!strncasecmp(cmdbuf,"CREU",4)) {
1015                 cmd_creu(&cmdbuf[5]);
1016         }
1017
1018         else if (!strncasecmp(cmdbuf,"SETP",4)) {
1019                 cmd_setp(&cmdbuf[5]);
1020         }
1021
1022         else if (!strncasecmp(cmdbuf,"LRMS",4)) {
1023                 cmd_lrms(&cmdbuf[5]);
1024         }
1025
1026         else if (!strncasecmp(cmdbuf,"LKRA",4)) {
1027                 cmd_lkra(&cmdbuf[5]);
1028         }
1029
1030         else if (!strncasecmp(cmdbuf,"LKRN",4)) {
1031                 cmd_lkrn(&cmdbuf[5]);
1032         }
1033
1034         else if (!strncasecmp(cmdbuf,"LKRO",4)) {
1035                 cmd_lkro(&cmdbuf[5]);
1036         }
1037
1038         else if (!strncasecmp(cmdbuf,"LZRM",4)) {
1039                 cmd_lzrm(&cmdbuf[5]);
1040         }
1041
1042         else if (!strncasecmp(cmdbuf,"LPRM",4)) {
1043                 cmd_lprm(&cmdbuf[5]);
1044         }
1045
1046         else if (!strncasecmp(cmdbuf,"GETU",4)) {
1047                 cmd_getu();
1048         }
1049
1050         else if (!strncasecmp(cmdbuf,"SETU",4)) {
1051                 cmd_setu(&cmdbuf[5]);
1052         }
1053
1054         else if (!strncasecmp(cmdbuf,"GOTO",4)) {
1055                 cmd_goto(&cmdbuf[5]);
1056         }
1057
1058         else if (!strncasecmp(cmdbuf,"MSGS",4)) {
1059                 cmd_msgs(&cmdbuf[5]);
1060         }
1061
1062         else if (!strncasecmp(cmdbuf,"WHOK",4)) {
1063                 cmd_whok();
1064         }
1065
1066         else if (!strncasecmp(cmdbuf,"RDIR",4)) {
1067                 cmd_rdir();
1068         }
1069
1070         else if (!strncasecmp(cmdbuf,"MSG0",4)) {
1071                 cmd_msg0(&cmdbuf[5]);
1072         }
1073
1074         else if (!strncasecmp(cmdbuf,"MSG2",4)) {
1075                 cmd_msg2(&cmdbuf[5]);
1076         }
1077
1078         else if (!strncasecmp(cmdbuf,"MSG3",4)) {
1079                 cmd_msg3(&cmdbuf[5]);
1080         }
1081
1082         else if (!strncasecmp(cmdbuf,"MSG4",4)) {
1083                 cmd_msg4(&cmdbuf[5]);
1084         }
1085
1086         else if (!strncasecmp(cmdbuf,"MSGP",4)) {
1087                 cmd_msgp(&cmdbuf[5]);
1088         }
1089
1090         else if (!strncasecmp(cmdbuf,"OPNA",4)) {
1091                 cmd_opna(&cmdbuf[5]);
1092         }
1093
1094         else if (!strncasecmp(cmdbuf,"INFO",4)) {
1095                 cmd_info();
1096         }
1097
1098         else if (!strncasecmp(cmdbuf,"SLRP",4)) {
1099                 cmd_slrp(&cmdbuf[5]);
1100         }
1101
1102         else if (!strncasecmp(cmdbuf,"INVT",4)) {
1103                 cmd_invt_kick(&cmdbuf[5],1);
1104         }
1105
1106         else if (!strncasecmp(cmdbuf,"KICK",4)) {
1107                 cmd_invt_kick(&cmdbuf[5],0);
1108         }
1109
1110         else if (!strncasecmp(cmdbuf,"GETR",4)) {
1111                 cmd_getr();
1112         }
1113
1114         else if (!strncasecmp(cmdbuf,"SETR",4)) {
1115                 cmd_setr(&cmdbuf[5]);
1116         }
1117
1118         else if (!strncasecmp(cmdbuf,"GETA",4)) {
1119                 cmd_geta();
1120         }
1121
1122         else if (!strncasecmp(cmdbuf,"SETA",4)) {
1123                 cmd_seta(&cmdbuf[5]);
1124         }
1125
1126         else if (!strncasecmp(cmdbuf,"ENT0",4)) {
1127                 cmd_ent0(&cmdbuf[5]);
1128         }
1129
1130         else if (!strncasecmp(cmdbuf,"RINF",4)) {
1131                 cmd_rinf();
1132         }
1133
1134         else if (!strncasecmp(cmdbuf,"DELE",4)) {
1135                 cmd_dele(&cmdbuf[5]);
1136         }
1137
1138         else if (!strncasecmp(cmdbuf,"KILL",4)) {
1139                 cmd_kill(&cmdbuf[5]);
1140         }
1141
1142         else if (!strncasecmp(cmdbuf,"CRE8",4)) {
1143                 cmd_cre8(&cmdbuf[5]);
1144         }
1145
1146         else if (!strncasecmp(cmdbuf,"MOVE",4)) {
1147                 cmd_move(&cmdbuf[5]);
1148         }
1149
1150         else if (!strncasecmp(cmdbuf,"FORG",4)) {
1151                 cmd_forg();
1152         }
1153
1154         else if (!strncasecmp(cmdbuf,"MESG",4)) {
1155                 cmd_mesg(&cmdbuf[5]);
1156         }
1157
1158         else if (!strncasecmp(cmdbuf,"EMSG",4)) {
1159                 cmd_emsg(&cmdbuf[5]);
1160         }
1161
1162         else if (!strncasecmp(cmdbuf,"GNUR",4)) {
1163                 cmd_gnur();
1164         }
1165
1166         else if (!strncasecmp(cmdbuf,"VALI",4)) {
1167                 cmd_vali(&cmdbuf[5]);
1168         }
1169
1170         else if (!strncasecmp(cmdbuf,"EINF",4)) {
1171                 cmd_einf(&cmdbuf[5]);
1172         }
1173
1174         else if (!strncasecmp(cmdbuf,"LIST",4)) {
1175                 cmd_list();
1176         }
1177
1178         else if (!strncasecmp(cmdbuf,"CHEK",4)) {
1179                 cmd_chek();
1180         }
1181
1182         else if (!strncasecmp(cmdbuf,"DELF",4)) {
1183                 cmd_delf(&cmdbuf[5]);
1184         }
1185
1186         else if (!strncasecmp(cmdbuf,"MOVF",4)) {
1187                 cmd_movf(&cmdbuf[5]);
1188         }
1189
1190         else if (!strncasecmp(cmdbuf,"NETF",4)) {
1191                 cmd_netf(&cmdbuf[5]);
1192         }
1193
1194         else if (!strncasecmp(cmdbuf,"OPEN",4)) {
1195                 cmd_open(&cmdbuf[5]);
1196         }
1197
1198         else if (!strncasecmp(cmdbuf,"CLOS",4)) {
1199                 cmd_clos();
1200         }
1201
1202         else if (!strncasecmp(cmdbuf,"UOPN",4)) {
1203                 cmd_uopn(&cmdbuf[5]);
1204         }
1205
1206         else if (!strncasecmp(cmdbuf,"UCLS",4)) {
1207                 cmd_ucls(&cmdbuf[5]);
1208         }
1209
1210         else if (!strncasecmp(cmdbuf,"READ",4)) {
1211                 cmd_read(&cmdbuf[5]);
1212         }
1213
1214         else if (!strncasecmp(cmdbuf,"WRIT",4)) {
1215                 cmd_writ(&cmdbuf[5]);
1216         }
1217
1218         else if (!strncasecmp(cmdbuf,"QUSR",4)) {
1219                 cmd_qusr(&cmdbuf[5]);
1220         }
1221
1222         else if (!strncasecmp(cmdbuf,"ECHO",4)) {
1223                 cmd_echo(&cmdbuf[5]);
1224         }
1225
1226         else if (!strncasecmp(cmdbuf,"OIMG",4)) {
1227                 cmd_oimg(&cmdbuf[5]);
1228         }
1229
1230         else if (!strncasecmp(cmdbuf,"MORE",4)) {
1231                 cmd_more();
1232         }
1233
1234         else if (!strncasecmp(cmdbuf,"NDOP",4)) {
1235                 cmd_ndop(&cmdbuf[5]);
1236         }
1237
1238         else if (!strncasecmp(cmdbuf,"NUOP",4)) {
1239                 cmd_nuop(&cmdbuf[5]);
1240         }
1241
1242         else if (!strncasecmp(cmdbuf,"LFLR",4)) {
1243                 cmd_lflr();
1244         }
1245
1246         else if (!strncasecmp(cmdbuf,"CFLR",4)) {
1247                 cmd_cflr(&cmdbuf[5]);
1248         }
1249
1250         else if (!strncasecmp(cmdbuf,"KFLR",4)) {
1251                 cmd_kflr(&cmdbuf[5]);
1252         }
1253
1254         else if (!strncasecmp(cmdbuf,"EFLR",4)) {
1255                 cmd_eflr(&cmdbuf[5]);
1256         }
1257
1258         else if (!strncasecmp(cmdbuf,"IDEN",4)) {
1259                 cmd_iden(&cmdbuf[5]);
1260         }
1261
1262         else if (!strncasecmp(cmdbuf,"IPGM",4)) {
1263                 cmd_ipgm(&cmdbuf[5]);
1264         }
1265
1266         else if (!strncasecmp(cmdbuf,"TERM",4)) {
1267                 cmd_term(&cmdbuf[5]);
1268         }
1269
1270         else if (!strncasecmp(cmdbuf,"DOWN",4)) {
1271                 cmd_down();
1272         }
1273
1274         else if (!strncasecmp(cmdbuf,"SCDN",4)) {
1275                 cmd_scdn(&cmdbuf[5]);
1276         }
1277
1278         else if (!strncasecmp(cmdbuf, "UIMG", 4)) {
1279                 cmd_uimg(&cmdbuf[5]);
1280         }
1281
1282         else if (!strncasecmp(cmdbuf, "TIME", 4)) {
1283                 cmd_time();
1284         }
1285
1286         else if (!strncasecmp(cmdbuf, "AGUP", 4)) {
1287                 cmd_agup(&cmdbuf[5]);
1288         }
1289
1290         else if (!strncasecmp(cmdbuf, "ASUP", 4)) {
1291                 cmd_asup(&cmdbuf[5]);
1292         }
1293
1294         else if (!strncasecmp(cmdbuf, "GPEX", 4)) {
1295                 cmd_gpex(&cmdbuf[5]);
1296         }
1297
1298         else if (!strncasecmp(cmdbuf, "SPEX", 4)) {
1299                 cmd_spex(&cmdbuf[5]);
1300         }
1301
1302         else if (!strncasecmp(cmdbuf, "CONF", 4)) {
1303                 cmd_conf(&cmdbuf[5]);
1304         }
1305
1306         else if (!strncasecmp(cmdbuf, "SEEN", 4)) {
1307                 cmd_seen(&cmdbuf[5]);
1308         }
1309
1310         else if (!strncasecmp(cmdbuf, "GTSN", 4)) {
1311                 cmd_gtsn(&cmdbuf[5]);
1312         }
1313
1314         else if (!strncasecmp(cmdbuf, "VIEW", 4)) {
1315                 cmd_view(&cmdbuf[5]);
1316         }
1317
1318         else if (!strncasecmp(cmdbuf, "ISME", 4)) {
1319                 cmd_isme(&cmdbuf[5]);
1320         }
1321
1322 #ifdef DEBUG_MEMORY_LEAKS
1323         else if (!strncasecmp(cmdbuf, "LEAK", 4)) {
1324                 dump_tracked();
1325         }
1326 #endif
1327
1328         else if (!DLoader_Exec_Cmd(cmdbuf)) {
1329                 cprintf("%d Unrecognized or unsupported command.\n", ERROR);
1330                }
1331
1332         /* Run any after-each-command outines registered by modules */
1333         PerformSessionHooks(EVT_CMD);
1334 }