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