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 <time.h>
  15 #include <ctype.h>
  16 #include <string.h>
  17 #include <errno.h>
  18 #include <limits.h>
  19 #include <syslog.h>
  20 #include <dlfcn.h>
  21 #include <netdb.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <sys/time.h>
  25 #include <netinet/in.h>
  26 #include <arpa/inet.h>
  27 #include "citadel.h"
  28 #include "server.h"
  29 #include "sysdep_decls.h"
  30 #include "citserver.h"
  31 #include "config.h"
  32 #include "database.h"
  33 #include "housekeeping.h"
  34 #include "user_ops.h"
  35 #include "logging.h"
  36 #include "msgbase.h"
  37 #include "support.h"
  38 #include "locate_host.h"
  39 #include "room_ops.h"
  40 #include "file_ops.h"
  41 #include "dynloader.h"
  42 #include "policy.h"
  43 #include "control.h"
  44 #include "tools.h"
  45
  46 struct CitContext *ContextList = NULL;
  47 char *unique_session_numbers;
  48 int ScheduledShutdown = 0;
  49 int do_defrag = 0;
  50
  51 /*
  52  * Various things that need to be initialized at startup
  53  */
  54 void master_startup(void) {
  55         struct timeval tv;
  56
  57         lprintf(7, "Opening databases\n");
  58         open_databases();
  59
  60         if (do_defrag)
  61                 defrag_databases();
  62
  63         lprintf(7, "Checking floor reference counts\n");
  64         check_ref_counts();
  65
  66         lprintf(7, "Creating base rooms (if necessary)\n");
  67         create_room(BASEROOM,           0, "", 0);
  68         create_room(AIDEROOM,           3, "", 0);
  69         create_room(SYSCONFIGROOM,      3, "", 0);
  70         create_room(config.c_twitroom,  0, "", 0);
  71
  72 /* Seed the PRNG */
  73
  74         lprintf(7, "Seeding the pseudo-random number generator...\n");
  75         gettimeofday(&tv, NULL);
  76         srand(tv.tv_usec);
  77 }
  78
  79 /*
  80  * Cleanup routine to be called when the server is shutting down.
  81  */
  82 void master_cleanup(void) {
  83         struct CleanupFunctionHook *fcn;
  84
  85         /* Cancel all running sessions */
  86         lprintf(7, "Cancelling running sessions...\n");
  87
  88 /* FIXME do something here
  89         while (ContextList != NULL) {
  90                 }
  91  */
  92
  93         /* Run any cleanup routines registered by loadable modules */
  94         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
  95                 (*fcn->h_function_pointer)();
  96                 }
  97
  98         /* Close databases */
  99         lprintf(7, "Closing databases\n");
 100         close_databases();
 101
 102         /* Do system-dependent stuff */
 103         sysdep_master_cleanup();
 104
 105         /* Now go away. */
 106         lprintf(3, "citserver: exiting.\n");
 107         fflush(stdout); fflush(stderr);
 108         exit(0);
 109         }
 110
 111
 112 /*
 113  * Free any per-session data allocated by modules or whatever
 114  */
 115 void deallocate_user_data(struct CitContext *con)
 116 {
 117         struct CtdlSessData *ptr;
 118
 119         begin_critical_section(S_SESSION_TABLE);
 120         while (con->FirstSessData != NULL) {
 121                 lprintf(9, "Deallocating user data symbol %ld\n",
 122                         con->FirstSessData->sym_id);
 123                 if (con->FirstSessData->sym_data != NULL)
 124                         phree(con->FirstSessData->sym_data);
 125                 ptr = con->FirstSessData->next;
 126                 phree(con->FirstSessData);
 127                 con->FirstSessData = ptr;
 128         }
 129         end_critical_section(S_SESSION_TABLE);
 130 }
 131
 132
 133
 134
 135 /*
 136  * Terminate a session and remove its context data structure.
 137  */
 138 void RemoveContext (struct CitContext *con)
 139 {
 140         struct CitContext *ptr = NULL;
 141         struct CitContext *ToFree = NULL;
 142
 143         lprintf(9, "RemoveContext() called\n");
 144         if (con==NULL) {
 145                 lprintf(5, "WARNING: RemoveContext() called with NULL!\n");
 146                 return;
 147                 }
 148
 149         /* Remove the context from the global context list.  This needs
 150          * to get done FIRST to avoid concurrency problems.  It is *vitally*
 151          * important to keep num_sessions accurate!!
 152          */
 153         lprintf(7, "Removing context for session %d\n", con->cs_pid);
 154         begin_critical_section(S_SESSION_TABLE);
 155         if (ContextList == con) {
 156                 ToFree = ContextList;
 157                 ContextList = ContextList->next;
 158                 --num_sessions;
 159                 }
 160         else {
 161                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 162                         if (ptr->next == con) {
 163                                 ToFree = ptr->next;
 164                                 ptr->next = ptr->next->next;
 165                                 --num_sessions;
 166                                 }
 167                         }
 168                 }
 169         end_critical_section(S_SESSION_TABLE);
 170
 171         if (ToFree == NULL) {
 172                 lprintf(9, "RemoveContext() found nothing to remove\n");
 173                 return;
 174         }
 175
 176         /* Run any cleanup routines registered by loadable modules.
 177          * Note 1: This must occur *before* deallocate_user_data() because the
 178          *         cleanup functions might touch dynamic session data.
 179          * Note 2: We have to "become_session()" because the cleanup functions
 180          *         might make references to "CC" assuming it's the right one.
 181          */
 182         become_session(con);
 183         PerformSessionHooks(EVT_STOP);
 184         become_session(NULL);
 185
 186         /* Now handle all of the administrivia. */
 187         lprintf(7, "Calling logout(%d)\n", con->cs_pid);
 188         logout(con);
 189
 190         rec_log(CL_TERMINATE, con->curr_user);
 191         unlink(con->temp);
 192         lprintf(3, "citserver[%3d]: ended.\n", con->cs_pid);
 193
 194
 195         syslog(LOG_NOTICE,"session %d ended", con->cs_pid);
 196
 197         /* Deallocate any user-data attached to this session */
 198         deallocate_user_data(con);
 199
 200         /* If the client is still connected, blow 'em away. */
 201         lprintf(7, "Closing socket %d\n", con->client_socket);
 202         close(con->client_socket);
 203
 204         /* Tell the housekeeping thread to check to see if this is the time
 205          * to initiate a scheduled shutdown event.
 206          */
 207         enter_housekeeping_cmd("SCHED_SHUTDOWN");
 208
 209         /* Free up the memory used by this context */
 210         phree(con);
 211
 212         lprintf(7, "Done with RemoveContext()\n");
 213 }
 214
 215
 216
 217 /*
 218  * Get a dynamic symbol number for per-session user data.
 219  * This API call should be made only ONCE per symbol per citserver run.
 220  */
 221 int CtdlGetDynamicSymbol()
 222 {
 223         static unsigned int next_symbol = SYM_MAX;
 224         return ++next_symbol;
 225 }
 226
 227
 228
 229 /*
 230  * Return a pointer to some generic per-session user data.
 231  * (This function returns NULL if the requested symbol is not allocated.)
 232  *
 233  * NOTE: we use critical sections for allocating and de-allocating these,
 234  *       but not for locating one.
 235  */
 236 void *CtdlGetUserData(unsigned long requested_sym)
 237 {
 238         struct CtdlSessData *ptr;
 239
 240         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)
 241                 if (ptr->sym_id == requested_sym)
 242                         return(ptr->sym_data);
 243
 244         lprintf(2, "ERROR! CtdlGetUserData(%ld) symbol not allocated\n",
 245                 requested_sym);
 246         return NULL;
 247 }
 248
 249
 250 /*
 251  * Allocate some generic per-session user data.
 252  */
 253 void CtdlAllocUserData(unsigned long requested_sym, size_t num_bytes)
 254 {
 255         struct CtdlSessData *ptr;
 256
 257         lprintf(9, "CtdlAllocUserData(%ld) called\n", requested_sym);
 258
 259         /* Fail silently if the symbol is already registered. */
 260         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)  {
 261                 if (ptr->sym_id == requested_sym) {
 262                         return;
 263                 }
 264         }
 265
 266         /* Grab us some memory!  Dem's good eatin' !!  */
 267         ptr = mallok(sizeof(struct CtdlSessData));
 268         ptr->sym_id = requested_sym;
 269         ptr->sym_data = mallok(num_bytes);
 270         memset(ptr->sym_data, 0, num_bytes);
 271
 272         begin_critical_section(S_SESSION_TABLE);
 273         ptr->next = CC->FirstSessData;
 274         CC->FirstSessData = ptr;
 275         end_critical_section(S_SESSION_TABLE);
 276
 277         lprintf(9, "CtdlAllocUserData(%ld) finished\n", requested_sym);
 278 }
 279
 280
 281 /*
 282  * Change the size of a buffer allocated with CtdlAllocUserData()
 283  */
 284 void CtdlReallocUserData(unsigned long requested_sym, size_t num_bytes)
 285 {
 286         struct CtdlSessData *ptr;
 287
 288         for (ptr = CC->FirstSessData; ptr != NULL; ptr = ptr->next)  {
 289                 if (ptr->sym_id == requested_sym) {
 290                         ptr->sym_data = reallok(ptr->sym_data, num_bytes);
 291                         return;
 292                 }
 293         }
 294
 295         lprintf(2, "CtdlReallocUserData() ERROR: symbol %ld not found!\n",
 296                 requested_sym);
 297 }
 298
 299
 300
 301
 302
 303
 304 /*
 305  * cmd_info()  -  tell the client about this server
 306  */
 307 void cmd_info(void) {
 308         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 309         cprintf("%d\n", CC->cs_pid);
 310         cprintf("%s\n", config.c_nodename);
 311         cprintf("%s\n", config.c_humannode);
 312         cprintf("%s\n", config.c_fqdn);
 313         cprintf("%s\n", CITADEL);
 314         cprintf("%d\n", REV_LEVEL);
 315         cprintf("%s\n", config.c_bbs_city);
 316         cprintf("%s\n", config.c_sysadm);
 317         cprintf("%d\n", SERVER_TYPE);
 318         cprintf("%s\n", config.c_moreprompt);
 319         cprintf("1\n"); /* 1 = yes, this system supports floors */
 320         cprintf("1\n"); /* 1 = we support the extended paging options */
 321         cprintf("%s\n", CC->cs_nonce);
 322         cprintf("000\n");
 323 }
 324
 325
 326 /*
 327  * returns an asterisk if there are any express messages waiting,
 328  * space otherwise.
 329  */
 330 char CtdlCheckExpress(void) {
 331         if (CC->FirstExpressMessage == NULL) {
 332                 return(' ');
 333                 }
 334         else {
 335                 return('*');
 336                 }
 337         }
 338
 339 void cmd_time(void)
 340 {
 341    time_t tv;
 342
 343    tv = time(NULL);
 344
 345    cprintf("%d %ld\n", OK, tv);
 346 }
 347
 348 /*
 349  * Check whether two hostnames match.
 350  * "Realname" should be an actual name of a client that is trying to connect;
 351  * "testname" should be the value we are comparing it with. The idea is that we
 352  * want to compare with both the abbreviated and fully-qualified versions of
 353  * "testname;" some people define "localhost" as "localhost.foo.com," etc.
 354  */
 355 static int hostnames_match(const char *realname, const char *testname) {
 356         struct hostent *he;
 357         int retval = 0;
 358
 359         if (!strcasecmp(realname, testname))
 360                 return 1;
 361
 362 #ifdef HAVE_NONREENTRANT_NETDB
 363         begin_critical_section(S_NETDB);
 364 #endif
 365
 366         if ((he = gethostbyname(testname)) != NULL)
 367                 if (!strcasecmp(realname, he->h_name))
 368                         retval = 1;
 369
 370 #ifdef HAVE_NONREENTRANT_NETDB
 371         end_critical_section(S_NETDB);
 372 #endif
 373
 374         return retval;
 375         }
 376
 377 /*
 378  * check a hostname against the public_clients file
 379  */
 380 int is_public_client(char *where)
 381 {
 382         char buf[256];
 383         FILE *fp;
 384
 385         lprintf(9, "Checking whether %s is a public client\n", where);
 386
 387         if (hostnames_match(where, "localhost")) return(1);
 388         if (hostnames_match(where, config.c_fqdn)) return(1);
 389
 390         fp = fopen("public_clients","r");
 391         if (fp == NULL) return(0);
 392
 393         while (fgets(buf,256,fp)!=NULL) {
 394                 while (isspace((buf[strlen(buf)-1])))
 395                         buf[strlen(buf)-1] = 0;
 396                 if (hostnames_match(where,buf)) {
 397                         fclose(fp);
 398                         return(1);
 399                         }
 400                 }
 401
 402         fclose(fp);
 403         return(0);
 404         }
 405
 406
 407 /*
 408  * the client is identifying itself to the server
 409  */
 410 void cmd_iden(char *argbuf)
 411 {
 412         int dev_code;
 413         int cli_code;
 414         int rev_level;
 415         char desc[256];
 416         char from_host[256];
 417         struct in_addr addr;
 418         int do_lookup = 0;
 419
 420         if (num_parms(argbuf)<4) {
 421                 cprintf("%d usage error\n",ERROR);
 422                 return;
 423         }
 424
 425         dev_code = extract_int(argbuf,0);
 426         cli_code = extract_int(argbuf,1);
 427         rev_level = extract_int(argbuf,2);
 428         extract(desc,argbuf,3);
 429
 430         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 431         from_host[sizeof from_host - 1] = 0;
 432         if (num_parms(argbuf)>=5) extract(from_host,argbuf,4);
 433
 434         CC->cs_clientdev = dev_code;
 435         CC->cs_clienttyp = cli_code;
 436         CC->cs_clientver = rev_level;
 437         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 438         CC->cs_clientname[31] = 0;
 439
 440         if (strlen(from_host) > 0) {
 441                 if (CC->is_local_socket) do_lookup = 1;
 442                 else if (is_public_client(CC->cs_host)) do_lookup = 1;
 443         }
 444
 445         if (do_lookup) {
 446                 lprintf(9, "Looking up hostname '%s'\n", from_host);
 447                 if ((addr.s_addr = inet_addr(from_host)) != -1) {
 448                         locate_host(CC->cs_host, &addr);
 449                 }
 450                 else {
 451                         safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 452                         CC->cs_host[24] = 0;
 453                 }
 454         }
 455
 456         lprintf(7, "client %d/%d/%01d.%02d (%s)\n",
 457                 dev_code,
 458                 cli_code,
 459                 (rev_level / 100),
 460                 (rev_level % 100),
 461                 desc);
 462
 463         syslog(LOG_NOTICE,"client %d/%d/%01d.%02d (%s)\n",
 464                 dev_code,
 465                 cli_code,
 466                 (rev_level / 100),
 467                 (rev_level % 100),
 468                 desc);
 469         cprintf("%d Ok\n",OK);
 470 }
 471
 472
 473 /*
 474  * display system messages or help
 475  */
 476 void cmd_mesg(char *mname)
 477 {
 478         FILE *mfp;
 479         char targ[256];
 480         char buf[256];
 481         char *dirs[2];
 482
 483         extract(buf,mname,0);
 484
 485
 486         dirs[0]=mallok(64);
 487         dirs[1]=mallok(64);
 488         strcpy(dirs[0],"messages");
 489         strcpy(dirs[1],"help");
 490         mesg_locate(targ,buf,2,dirs);
 491         phree(dirs[0]);
 492         phree(dirs[1]);
 493
 494
 495         if (strlen(targ)==0) {
 496                 cprintf("%d '%s' not found.\n",ERROR,mname);
 497                 return;
 498                 }
 499
 500         mfp = fopen(targ,"r");
 501         if (mfp==NULL) {
 502                 cprintf("%d Cannot open '%s': %s\n",
 503                         ERROR,targ,strerror(errno));
 504                 return;
 505                 }
 506         cprintf("%d %s\n",LISTING_FOLLOWS,buf);
 507
 508         while (fgets(buf,255,mfp)!=NULL) {
 509                 buf[strlen(buf)-1] = 0;
 510                 do_help_subst(buf);
 511                 cprintf("%s\n",buf);
 512                 }
 513
 514         fclose(mfp);
 515         cprintf("000\n");
 516         }
 517
 518
 519 /*
 520  * enter system messages or help
 521  */
 522 void cmd_emsg(char *mname)
 523 {
 524         FILE *mfp;
 525         char targ[256];
 526         char buf[256];
 527         char *dirs[2];
 528         int a;
 529
 530         if (CtdlAccessCheck(ac_aide)) return;
 531
 532         extract(buf,mname,0);
 533         for (a=0; a<strlen(buf); ++a) {         /* security measure */
 534                 if (buf[a] == '/') buf[a] = '.';
 535                 }
 536
 537         dirs[0]=mallok(64);
 538         dirs[1]=mallok(64);
 539         strcpy(dirs[0],"messages");
 540         strcpy(dirs[1],"help");
 541         mesg_locate(targ,buf,2,dirs);
 542         phree(dirs[0]);
 543         phree(dirs[1]);
 544
 545         if (strlen(targ)==0) {
 546                 snprintf(targ, sizeof targ, "./help/%s", buf);
 547                 }
 548
 549         mfp = fopen(targ,"w");
 550         if (mfp==NULL) {
 551                 cprintf("%d Cannot open '%s': %s\n",
 552                         ERROR,targ,strerror(errno));
 553                 return;
 554                 }
 555         cprintf("%d %s\n", SEND_LISTING, targ);
 556
 557         while (client_gets(buf), strcmp(buf, "000")) {
 558                 fprintf(mfp, "%s\n", buf);
 559                 }
 560
 561         fclose(mfp);
 562         }
 563
 564
 565 /* Don't show the names of private rooms unless the viewing
 566  * user also knows the rooms.
 567  */
 568 void GenerateRoomDisplay(char *real_room,
 569                         struct CitContext *viewed,
 570                         struct CitContext *viewer) {
 571
 572         strcpy(real_room, viewed->quickroom.QRname);
 573         if (viewed->quickroom.QRflags & QR_MAILBOX) {
 574                 strcpy(real_room, &real_room[11]);
 575         }
 576         if (viewed->quickroom.QRflags & QR_PRIVATE) {
 577                 if ( (CtdlRoomAccess(&viewed->quickroom, &viewer->usersupp)
 578                    & UA_KNOWN) == 0) {
 579                         strcpy(real_room, "<private room>");
 580                 }
 581         }
 582
 583         if (viewed->cs_flags & CS_CHAT) {
 584                 while (strlen(real_room) < 14)
 585                         strcat(real_room, " ");
 586
 587                 strcpy(&real_room[14], "<chat>");
 588         }
 589
 590 }
 591
 592 /*
 593  * Convenience function.
 594  */
 595 int CtdlAccessCheck(int required_level) {
 596
 597         if (CC->internal_pgm) return(0);
 598         if (required_level >= ac_internal) {
 599                 cprintf("%d This is not a user-level command.\n",
 600                         ERROR+HIGHER_ACCESS_REQUIRED);
 601                 return(-1);
 602         }
 603
 604         if (CC->usersupp.axlevel >= 6) return(0);
 605         if (required_level >= ac_aide) {
 606                 cprintf("%d This command requires Aide access.\n",
 607                         ERROR+HIGHER_ACCESS_REQUIRED);
 608                 return(-1);
 609         }
 610
 611         if (is_room_aide()) return(0);
 612         if (required_level >= ac_room_aide) {
 613                 cprintf("%d This command requires Aide or Room Aide access.\n",
 614                         ERROR + HIGHER_ACCESS_REQUIRED);
 615                 return(-1);
 616         }
 617
 618         if (CC->logged_in) return(0);
 619         if (required_level >= ac_logged_in) {
 620                 cprintf("%d Not logged in.\n", ERROR+NOT_LOGGED_IN);
 621                 return(-1);
 622         }
 623
 624         /* shhh ... succeed quietly */
 625         return(0);
 626 }
 627
 628
 629
 630 /*
 631  * Terminate another running session
 632  */
 633 void cmd_term(char *cmdbuf)
 634 {
 635         int session_num;
 636         struct CitContext *ccptr;
 637         int found_it = 0;
 638
 639         if (CtdlAccessCheck(ac_aide)) return;
 640
 641         session_num = extract_int(cmdbuf, 0);
 642         if (session_num == CC->cs_pid) {
 643                 cprintf("%d You can't kill your own session.\n", ERROR);
 644                 return;
 645                 }
 646
 647         lprintf(9, "Locating session to kill\n");
 648         begin_critical_section(S_SESSION_TABLE);
 649         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 650                 if (session_num == ccptr->cs_pid) {
 651                         ccptr->kill_me = 1;
 652                         found_it = 1;
 653                         }
 654                 }
 655         end_critical_section(S_SESSION_TABLE);
 656
 657         if (found_it) {
 658                 cprintf("%d Session terminated.\n", OK);
 659                 }
 660         else {
 661                 cprintf("%d No such session.\n", ERROR);
 662                 }
 663         }
 664
 665
 666
 667
 668
 669 /*
 670  * get the paginator prompt
 671  */
 672 void cmd_more(void) {
 673         cprintf("%d %s\n",OK,config.c_moreprompt);
 674         }
 675
 676 /*
 677  * echo
 678  */
 679 void cmd_echo(char *etext)
 680 {
 681         cprintf("%d %s\n",OK,etext);
 682         }
 683
 684
 685
 686 /*
 687  * identify as internal program
 688  */
 689 void cmd_ipgm(char *argbuf)
 690 {
 691         int secret;
 692
 693         secret = extract_int(argbuf, 0);
 694         if (secret == config.c_ipgm_secret) {
 695                 CC->internal_pgm = 1;
 696                 strcpy(CC->curr_user, "<internal program>");
 697                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 698                 cprintf("%d Authenticated as an internal program.\n",OK);
 699                 }
 700         else {
 701                 cprintf("%d Authentication failed.\n",ERROR);
 702                 lprintf(3, "Warning: ipgm authentication failed.\n");
 703                 }
 704         }
 705
 706
 707 /*
 708  * Shut down the server
 709  */
 710 void cmd_down(void) {
 711
 712         if (CtdlAccessCheck(ac_aide)) return;
 713
 714         cprintf("%d Shutting down server.  Goodbye.\n", OK);
 715         master_cleanup();
 716         }
 717
 718 /*
 719  * Schedule or cancel a server shutdown
 720  */
 721 void cmd_scdn(char *argbuf)
 722 {
 723         int new_state;
 724
 725         if (CtdlAccessCheck(ac_aide)) return;
 726
 727         new_state = extract_int(argbuf, 0);
 728         if ((new_state == 0) || (new_state == 1)) {
 729                 ScheduledShutdown = new_state;
 730                 }
 731         cprintf("%d %d\n", OK, ScheduledShutdown);
 732         }
 733
 734
 735 /*
 736  * Generate a "nonce" for APOP-style authentication.
 737  *
 738  * RFC 1725 et al specify a PID to be placed in front of the nonce.
 739  * Quoth BTX: That would be stupid.
 740  */
 741 void generate_nonce(struct CitContext *con) {
 742         struct timeval tv;
 743
 744         memset(con->cs_nonce, NONCE_SIZE, 0);
 745         gettimeofday(&tv, NULL);
 746         memset(con->cs_nonce, NONCE_SIZE, 0);
 747         snprintf(con->cs_nonce, NONCE_SIZE, "<%d%ld@%s>",
 748                 rand(), tv.tv_usec, config.c_fqdn);
 749 }
 750
 751
 752
 753
 754 /*
 755  * Back-end function for starting a session
 756  */
 757 void begin_session(struct CitContext *con)
 758 {
 759         int len;
 760         struct sockaddr_in sin;
 761
 762         /*
 763          * Initialize some variables specific to our context.
 764          */
 765         con->logged_in = 0;
 766         con->internal_pgm = 0;
 767         con->download_fp = NULL;
 768         con->upload_fp = NULL;
 769         con->FirstExpressMessage = NULL;
 770         time(&con->lastcmd);
 771         time(&con->lastidle);
 772         strcpy(con->lastcmdname, "    ");
 773         strcpy(con->cs_clientname, "(unknown)");
 774         strcpy(con->curr_user, NLI);
 775         strcpy(con->net_node,"");
 776         strcpy(con->fake_username, "");
 777         strcpy(con->fake_postname, "");
 778         strcpy(con->fake_hostname, "");
 779         strcpy(con->fake_roomname, "");
 780         generate_nonce(con);
 781         snprintf(con->temp, sizeof con->temp, tmpnam(NULL));
 782         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 783         con->cs_host[sizeof con->cs_host - 1] = 0;
 784         len = sizeof sin;
 785         if (!CC->is_local_socket) {
 786                 if (!getpeername(con->client_socket,
 787                    (struct sockaddr *) &sin, &len))
 788                         locate_host(con->cs_host, &sin.sin_addr);
 789         }
 790         else {
 791                 strcpy(con->cs_host, "");
 792         }
 793         con->cs_flags = 0;
 794         con->upload_type = UPL_FILE;
 795         con->dl_is_net = 0;
 796         con->FirstSessData = NULL;
 797
 798         con->nologin = 0;
 799         if ((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions))
 800                 con->nologin = 1;
 801
 802         lprintf(3, "citserver[%3d]: started.\n", con->cs_pid);
 803
 804         /* Run any session startup routines registered by loadable modules */
 805         PerformSessionHooks(EVT_START);
 806
 807         rec_log(CL_CONNECT, "");
 808 }
 809
 810
 811 void citproto_begin_session() {
 812         if (CC->nologin==1) {
 813                 cprintf("%d %s: Too many users are already online "
 814                         "(maximum is %d)\n",
 815                         ERROR+MAX_SESSIONS_EXCEEDED,
 816                         config.c_nodename, config.c_maxsessions);
 817                 }
 818         else {
 819                 cprintf("%d %s Citadel/UX server ready.\n",
 820                         OK, config.c_nodename);
 821                 }
 822 }
 823
 824
 825
 826
 827 /*
 828  * This loop recognizes all server commands.
 829  */
 830 void do_command_loop(void) {
 831         char cmdbuf[256];
 832
 833         time(&CC->lastcmd);
 834         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 835         if (client_gets(cmdbuf) < 1) {
 836                 lprintf(3, "Client socket is broken.  Ending session.\n");
 837                 CC->kill_me = 1;
 838                 return;
 839         }
 840         lprintf(5, "citserver[%3d]: %s\n", CC->cs_pid, cmdbuf);
 841
 842         /*
 843          * Let other clients see the last command we executed, and
 844          * update the idle time, but not NOOP, PEXP, or GEXP.
 845          */
 846         if ( (strncasecmp(cmdbuf, "NOOP", 4))
 847            && (strncasecmp(cmdbuf, "PEXP", 4))
 848            && (strncasecmp(cmdbuf, "GEXP", 4)) ) {
 849                 strcpy(CC->lastcmdname, "    ");
 850                 safestrncpy(CC->lastcmdname, cmdbuf,
 851                         sizeof(CC->lastcmdname) );
 852                 time(&CC->lastidle);
 853                 }
 854
 855         if ((strncasecmp(cmdbuf, "ENT0", 4))
 856            && (strncasecmp(cmdbuf, "MESG", 4))
 857            && (strncasecmp(cmdbuf, "MSGS", 4)))
 858         {
 859            CC->cs_flags &= ~CS_POSTING;
 860         }
 861
 862         if (!strncasecmp(cmdbuf,"NOOP",4)) {
 863                 cprintf("%d%cok\n",OK,CtdlCheckExpress());
 864                 }
 865
 866         else if (!strncasecmp(cmdbuf,"QUIT",4)) {
 867                 cprintf("%d Goodbye.\n",OK);
 868                 CC->kill_me = 1;
 869                 }
 870
 871         else if (!strncasecmp(cmdbuf,"LOUT",4)) {
 872                 if (CC->logged_in) logout(CC);
 873                 cprintf("%d logged out.\n",OK);
 874                 }
 875
 876         else if (!strncasecmp(cmdbuf,"USER",4)) {
 877                 cmd_user(&cmdbuf[5]);
 878                 }
 879
 880         else if (!strncasecmp(cmdbuf,"PASS",4)) {
 881                 cmd_pass(&cmdbuf[5]);
 882                 }
 883
 884         else if (!strncasecmp(cmdbuf,"NEWU",4)) {
 885                 cmd_newu(&cmdbuf[5]);
 886                 }
 887
 888         else if (!strncasecmp(cmdbuf,"SETP",4)) {
 889                 cmd_setp(&cmdbuf[5]);
 890                 }
 891
 892         else if (!strncasecmp(cmdbuf,"LRMS",4)) {
 893                 cmd_lrms(&cmdbuf[5]);
 894                 }
 895
 896         else if (!strncasecmp(cmdbuf,"LKRA",4)) {
 897                 cmd_lkra(&cmdbuf[5]);
 898                 }
 899
 900         else if (!strncasecmp(cmdbuf,"LKRN",4)) {
 901                 cmd_lkrn(&cmdbuf[5]);
 902                 }
 903
 904         else if (!strncasecmp(cmdbuf,"LKRO",4)) {
 905                 cmd_lkro(&cmdbuf[5]);
 906                 }
 907
 908         else if (!strncasecmp(cmdbuf,"LZRM",4)) {
 909                 cmd_lzrm(&cmdbuf[5]);
 910                 }
 911
 912         else if (!strncasecmp(cmdbuf,"GETU",4)) {
 913                 cmd_getu();
 914                 }
 915
 916         else if (!strncasecmp(cmdbuf,"SETU",4)) {
 917                 cmd_setu(&cmdbuf[5]);
 918                 }
 919
 920         else if (!strncasecmp(cmdbuf,"GOTO",4)) {
 921                 cmd_goto(&cmdbuf[5]);
 922                 }
 923
 924         else if (!strncasecmp(cmdbuf,"MSGS",4)) {
 925                 cmd_msgs(&cmdbuf[5]);
 926                 }
 927
 928         else if (!strncasecmp(cmdbuf,"WHOK",4)) {
 929                 cmd_whok();
 930                 }
 931
 932         else if (!strncasecmp(cmdbuf,"RDIR",4)) {
 933                 cmd_rdir();
 934                 }
 935
 936         else if (!strncasecmp(cmdbuf,"MSG0",4)) {
 937                 cmd_msg0(&cmdbuf[5]);
 938                 }
 939
 940         else if (!strncasecmp(cmdbuf,"MSG2",4)) {
 941                 cmd_msg2(&cmdbuf[5]);
 942                 }
 943
 944         else if (!strncasecmp(cmdbuf,"MSG3",4)) {
 945                 cmd_msg3(&cmdbuf[5]);
 946                 }
 947
 948         else if (!strncasecmp(cmdbuf,"MSG4",4)) {
 949                 cmd_msg4(&cmdbuf[5]);
 950                 }
 951
 952         else if (!strncasecmp(cmdbuf,"OPNA",4)) {
 953                 cmd_opna(&cmdbuf[5]);
 954                 }
 955
 956         else if (!strncasecmp(cmdbuf,"INFO",4)) {
 957                 cmd_info();
 958                 }
 959
 960         else if (!strncasecmp(cmdbuf,"SLRP",4)) {
 961                 cmd_slrp(&cmdbuf[5]);
 962                 }
 963
 964         else if (!strncasecmp(cmdbuf,"INVT",4)) {
 965                 cmd_invt_kick(&cmdbuf[5],1);
 966                 }
 967
 968         else if (!strncasecmp(cmdbuf,"KICK",4)) {
 969                 cmd_invt_kick(&cmdbuf[5],0);
 970                 }
 971
 972         else if (!strncasecmp(cmdbuf,"GETR",4)) {
 973                 cmd_getr();
 974                 }
 975
 976         else if (!strncasecmp(cmdbuf,"SETR",4)) {
 977                 cmd_setr(&cmdbuf[5]);
 978                 }
 979
 980         else if (!strncasecmp(cmdbuf,"GETA",4)) {
 981                 cmd_geta();
 982                 }
 983
 984         else if (!strncasecmp(cmdbuf,"SETA",4)) {
 985                 cmd_seta(&cmdbuf[5]);
 986                 }
 987
 988         else if (!strncasecmp(cmdbuf,"ENT0",4)) {
 989                 cmd_ent0(&cmdbuf[5]);
 990                 }
 991
 992         else if (!strncasecmp(cmdbuf,"ENT3",4)) {
 993                 cmd_ent3(&cmdbuf[5]);
 994                 }
 995
 996         else if (!strncasecmp(cmdbuf,"RINF",4)) {
 997                 cmd_rinf();
 998                 }
 999
1000         else if (!strncasecmp(cmdbuf,"DELE",4)) {
1001                 cmd_dele(&cmdbuf[5]);
1002                 }
1003
1004         else if (!strncasecmp(cmdbuf,"KILL",4)) {
1005                 cmd_kill(&cmdbuf[5]);
1006                 }
1007
1008         else if (!strncasecmp(cmdbuf,"CRE8",4)) {
1009                 cmd_cre8(&cmdbuf[5]);
1010                 }
1011
1012         else if (!strncasecmp(cmdbuf,"MOVE",4)) {
1013                 cmd_move(&cmdbuf[5]);
1014                 }
1015
1016         else if (!strncasecmp(cmdbuf,"FORG",4)) {
1017                 cmd_forg();
1018                 }
1019
1020         else if (!strncasecmp(cmdbuf,"MESG",4)) {
1021                 cmd_mesg(&cmdbuf[5]);
1022                 }
1023
1024         else if (!strncasecmp(cmdbuf,"EMSG",4)) {
1025                 cmd_emsg(&cmdbuf[5]);
1026                 }
1027
1028         else if (!strncasecmp(cmdbuf,"GNUR",4)) {
1029                 cmd_gnur();
1030                 }
1031
1032         else if (!strncasecmp(cmdbuf,"VALI",4)) {
1033                 cmd_vali(&cmdbuf[5]);
1034                 }
1035
1036         else if (!strncasecmp(cmdbuf,"EINF",4)) {
1037                 cmd_einf(&cmdbuf[5]);
1038                 }
1039
1040         else if (!strncasecmp(cmdbuf,"LIST",4)) {
1041                 cmd_list();
1042                 }
1043
1044         else if (!strncasecmp(cmdbuf,"CHEK",4)) {
1045                 cmd_chek();
1046                 }
1047
1048         else if (!strncasecmp(cmdbuf,"DELF",4)) {
1049                 cmd_delf(&cmdbuf[5]);
1050                 }
1051
1052         else if (!strncasecmp(cmdbuf,"MOVF",4)) {
1053                 cmd_movf(&cmdbuf[5]);
1054                 }
1055
1056         else if (!strncasecmp(cmdbuf,"NETF",4)) {
1057                 cmd_netf(&cmdbuf[5]);
1058                 }
1059
1060         else if (!strncasecmp(cmdbuf,"OPEN",4)) {
1061                 cmd_open(&cmdbuf[5]);
1062                 }
1063
1064         else if (!strncasecmp(cmdbuf,"CLOS",4)) {
1065                 cmd_clos();
1066                 }
1067
1068         else if (!strncasecmp(cmdbuf,"UOPN",4)) {
1069                 cmd_uopn(&cmdbuf[5]);
1070                 }
1071
1072         else if (!strncasecmp(cmdbuf,"UCLS",4)) {
1073                 cmd_ucls(&cmdbuf[5]);
1074                 }
1075
1076         else if (!strncasecmp(cmdbuf,"READ",4)) {
1077                 cmd_read(&cmdbuf[5]);
1078                 }
1079
1080         else if (!strncasecmp(cmdbuf,"WRIT",4)) {
1081                 cmd_writ(&cmdbuf[5]);
1082                 }
1083
1084         else if (!strncasecmp(cmdbuf,"QUSR",4)) {
1085                 cmd_qusr(&cmdbuf[5]);
1086                 }
1087
1088         else if (!strncasecmp(cmdbuf,"ECHO",4)) {
1089                 cmd_echo(&cmdbuf[5]);
1090                 }
1091
1092         else if (!strncasecmp(cmdbuf,"OIMG",4)) {
1093                 cmd_oimg(&cmdbuf[5]);
1094                 }
1095
1096         else if (!strncasecmp(cmdbuf,"MORE",4)) {
1097                 cmd_more();
1098                 }
1099
1100         else if (!strncasecmp(cmdbuf,"NETP",4)) {
1101                 cmd_netp(&cmdbuf[5]);
1102                 }
1103
1104         else if (!strncasecmp(cmdbuf,"NDOP",4)) {
1105                 cmd_ndop(&cmdbuf[5]);
1106                 }
1107
1108         else if (!strncasecmp(cmdbuf,"NUOP",4)) {
1109                 cmd_nuop(&cmdbuf[5]);
1110                 }
1111
1112         else if (!strncasecmp(cmdbuf,"LFLR",4)) {
1113                 cmd_lflr();
1114                 }
1115
1116         else if (!strncasecmp(cmdbuf,"CFLR",4)) {
1117                 cmd_cflr(&cmdbuf[5]);
1118                 }
1119
1120         else if (!strncasecmp(cmdbuf,"KFLR",4)) {
1121                 cmd_kflr(&cmdbuf[5]);
1122                 }
1123
1124         else if (!strncasecmp(cmdbuf,"EFLR",4)) {
1125                 cmd_eflr(&cmdbuf[5]);
1126                 }
1127
1128         else if (!strncasecmp(cmdbuf,"IDEN",4)) {
1129                 cmd_iden(&cmdbuf[5]);
1130                 }
1131
1132         else if (!strncasecmp(cmdbuf,"IPGM",4)) {
1133                 cmd_ipgm(&cmdbuf[5]);
1134                 }
1135
1136         else if (!strncasecmp(cmdbuf,"TERM",4)) {
1137                 cmd_term(&cmdbuf[5]);
1138                 }
1139
1140         else if (!strncasecmp(cmdbuf,"DOWN",4)) {
1141                 cmd_down();
1142                 }
1143
1144         else if (!strncasecmp(cmdbuf,"SCDN",4)) {
1145                 cmd_scdn(&cmdbuf[5]);
1146                 }
1147
1148         else if (!strncasecmp(cmdbuf, "NSET", 4)) {
1149                 cmd_nset(&cmdbuf[5]);
1150                 }
1151
1152         else if (!strncasecmp(cmdbuf, "UIMG", 4)) {
1153                 cmd_uimg(&cmdbuf[5]);
1154                 }
1155
1156         else if (!strncasecmp(cmdbuf, "TIME", 4)) {
1157                 cmd_time();
1158                 }
1159
1160         else if (!strncasecmp(cmdbuf, "AGUP", 4)) {
1161                 cmd_agup(&cmdbuf[5]);
1162                 }
1163
1164         else if (!strncasecmp(cmdbuf, "ASUP", 4)) {
1165                 cmd_asup(&cmdbuf[5]);
1166                 }
1167
1168         else if (!strncasecmp(cmdbuf, "GPEX", 4)) {
1169                 cmd_gpex(&cmdbuf[5]);
1170                 }
1171
1172         else if (!strncasecmp(cmdbuf, "SPEX", 4)) {
1173                 cmd_spex(&cmdbuf[5]);
1174                 }
1175
1176         else if (!strncasecmp(cmdbuf, "CONF", 4)) {
1177                 cmd_conf(&cmdbuf[5]);
1178                 }
1179
1180 #ifdef DEBUG_MEMORY_LEAKS
1181         else if (!strncasecmp(cmdbuf, "LEAK", 4)) {
1182                 dump_tracked();
1183                 }
1184 #endif
1185
1186         else if (!DLoader_Exec_Cmd(cmdbuf))
1187                 {
1188                    cprintf("%d Unrecognized or unsupported command.\n",
1189                             ERROR);
1190                 }
1191
1192         /* Run any after-each-command outines registered by modules */
1193         PerformSessionHooks(EVT_CMD);
1194 }