citadel/citserver.c

   1 /*
   2  * $Id$
   3  *
   4  * Main source module for the Citadel server
   5  *
   6  */
   7
   8 #include "sysdep.h"
   9 #include <stdlib.h>
  10 #include <unistd.h>
  11 #include <stdio.h>
  12 #include <fcntl.h>
  13 #include <signal.h>
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16
  17
  18 #if TIME_WITH_SYS_TIME
  19 # include <sys/time.h>
  20 # include <time.h>
  21 #else
  22 # if HAVE_SYS_TIME_H
  23 #  include <sys/time.h>
  24 # else
  25 #  include <time.h>
  26 # endif
  27 #endif
  28
  29 #include <ctype.h>
  30 #include <string.h>
  31 #include <dirent.h>
  32 #include <errno.h>
  33 #include <limits.h>
  34 #include <netdb.h>
  35 #include <sys/types.h>
  36 #include <sys/socket.h>
  37 #include <netinet/in.h>
  38 #include <arpa/inet.h>
  39 #include "citadel.h"
  40 #include "server.h"
  41 #include "serv_extensions.h"
  42 #include "sysdep_decls.h"
  43 #include "citserver.h"
  44 #include "config.h"
  45 #include "database.h"
  46 #include "housekeeping.h"
  47 #include "user_ops.h"
  48 #include "msgbase.h"
  49 #include "support.h"
  50 #include "locate_host.h"
  51 #include "room_ops.h"
  52 #include "file_ops.h"
  53 #include "policy.h"
  54 #include "control.h"
  55 #include "tools.h"
  56 #include "euidindex.h"
  57
  58 #ifndef HAVE_SNPRINTF
  59 #include "snprintf.h"
  60 #endif
  61
  62 struct CitContext *ContextList = NULL;
  63 struct CitContext* next_session = NULL;
  64 char *unique_session_numbers;
  65 int ScheduledShutdown = 0;
  66 int do_defrag = 0;
  67 time_t server_startup_time;
  68 char pid_file_name[PATH_MAX];
  69
  70 /*
  71  * Various things that need to be initialized at startup
  72  */
  73 void master_startup(void) {
  74         struct timeval tv;
  75         unsigned int seed;
  76         FILE *urandom;
  77         struct ctdlroom qrbuf;
  78         FILE *pidfile_fp;
  79
  80         lprintf(CTDL_DEBUG, "master_startup() started\n");
  81         time(&server_startup_time);
  82
  83         /* pid file.  If we go FSSTND this should end up in 'localstatedir' */
  84         snprintf(pid_file_name, sizeof pid_file_name, "./citadel.pid");
  85         pidfile_fp = fopen(pid_file_name, "w");
  86         if (pidfile_fp != NULL) {
  87                 fprintf(pidfile_fp, "%d\n", (int)getpid());
  88                 fclose(pidfile_fp);
  89         }
  90
  91         lprintf(CTDL_INFO, "Opening databases\n");
  92         open_databases();
  93
  94         if (do_defrag) {
  95                 defrag_databases();
  96         }
  97
  98         check_ref_counts();
  99
 100         lprintf(CTDL_INFO, "Creating base rooms (if necessary)\n");
 101         create_room(config.c_baseroom,  0, "", 0, 1, 0, VIEW_BBS);
 102         create_room(AIDEROOM,           3, "", 0, 1, 0, VIEW_BBS);
 103         create_room(SYSCONFIGROOM,      3, "", 0, 1, 0, VIEW_BBS);
 104         create_room(config.c_twitroom,  0, "", 0, 1, 0, VIEW_BBS);
 105
 106         /* The "Local System Configuration" room doesn't need to be visible */
 107         if (lgetroom(&qrbuf, SYSCONFIGROOM) == 0) {
 108                 qrbuf.QRflags2 |= QR2_SYSTEM;
 109                 lputroom(&qrbuf);
 110         }
 111
 112         /*
 113          * Create a room in which we can deposit "deleted" messages for
 114          * deferred deletion.  This will silently fail if the room already
 115          * exists, and that's perfectly ok, because we want it to exist.
 116          */
 117         create_room(DELETED_MSGS_ROOM, 3, "", 0, 1, 0, VIEW_MAILBOX);
 118
 119         /*
 120          * Make sure it's set to be a "system room" so it doesn't show up
 121          * in the <K>nown rooms list for Aides.  Also set the message expire
 122          * policy to "by count, 1 message" so everything gets deleted all
 123          * the time (we can't set it to 0 because that's invalid, so we keep
 124          * a single message around).
 125          */
 126         if (lgetroom(&qrbuf, DELETED_MSGS_ROOM) == 0) {
 127                 qrbuf.QRflags2 |= QR2_SYSTEM;
 128                 qrbuf.QRep.expire_mode = EXPIRE_NUMMSGS;
 129                 qrbuf.QRep.expire_value = 1;
 130                 lputroom(&qrbuf);
 131         }
 132
 133         lprintf(CTDL_INFO, "Seeding the pseudo-random number generator...\n");
 134         urandom = fopen("/dev/urandom", "r");
 135         if (urandom != NULL) {
 136                 fread(&seed, sizeof seed, 1, urandom);
 137                 fclose(urandom);
 138         }
 139         else {
 140                 gettimeofday(&tv, NULL);
 141                 seed = tv.tv_usec;
 142         }
 143         srandom(seed);
 144
 145         lprintf(CTDL_INFO, "Initializing ipgm secret\n");
 146         get_config();
 147         config.c_ipgm_secret = rand();
 148         put_config();
 149
 150         lprintf(CTDL_DEBUG, "master_startup() finished\n");
 151 }
 152
 153
 154 /*
 155  * Cleanup routine to be called when the server is shutting down.
 156  */
 157 void master_cleanup(int exitcode) {
 158         struct CleanupFunctionHook *fcn;
 159         static int already_cleaning_up = 0;
 160
 161         if (already_cleaning_up) while(1) sleep(1);
 162         already_cleaning_up = 1;
 163
 164         /* Run any cleanup routines registered by loadable modules */
 165         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 166                 (*fcn->h_function_pointer)();
 167         }
 168
 169         /* Shut down the indexer thread */
 170         lprintf(CTDL_INFO, "Waiting for the indexer thread to shut down\n");
 171         pthread_join(indexer_thread_tid, NULL);
 172
 173         /* Shut down the checkpoint thread */
 174         lprintf(CTDL_INFO, "Waiting for the checkpoint thread to shut down\n");
 175         pthread_join(checkpoint_thread_tid, NULL);
 176
 177         /* Close databases */
 178         lprintf(CTDL_INFO, "Closing databases\n");
 179         close_databases();
 180
 181         /* Do system-dependent stuff */
 182         sysdep_master_cleanup();
 183
 184 #ifdef DEBUG_MEMORY_LEAKS
 185         dump_heap();
 186 #endif
 187
 188         /* If the operator requested a halt but not an exit, halt here. */
 189         if (shutdown_and_halt) {
 190                 lprintf(CTDL_NOTICE, "citserver: Halting server without exiting.\n");
 191                 fflush(stdout); fflush(stderr);
 192                 while(1) {
 193                         sleep(32767);
 194                 }
 195         }
 196
 197         /* Now go away. */
 198         lprintf(CTDL_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 199         fflush(stdout); fflush(stderr);
 200
 201         unlink(pid_file_name);
 202         exit(exitcode);
 203 }
 204
 205
 206
 207 /*
 208  * Terminate a session.
 209  */
 210 void RemoveContext (struct CitContext *con)
 211 {
 212         if (con==NULL) {
 213                 lprintf(CTDL_ERR,
 214                         "WARNING: RemoveContext() called with NULL!\n");
 215                 return;
 216         }
 217         lprintf(CTDL_DEBUG, "RemoveContext() session %d\n", con->cs_pid);
 218
 219         /* Run any cleanup routines registered by loadable modules.
 220          * Note: 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(CTDL_DEBUG, "Calling logout(%d)\n", con->cs_pid);
 229         logout(con);
 230
 231         lprintf(CTDL_NOTICE, "[%3d] Session ended.\n", con->cs_pid);
 232
 233         /* If the client is still connected, blow 'em away. */
 234         lprintf(CTDL_DEBUG, "Closing socket %d\n", con->client_socket);
 235         close(con->client_socket);
 236
 237         lprintf(CTDL_DEBUG, "Done with RemoveContext()\n");
 238 }
 239
 240
 241
 242
 243
 244 /*
 245  * cmd_info()  -  tell the client about this server
 246  */
 247 void cmd_info(void) {
 248         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 249         cprintf("%d\n", CC->cs_pid);
 250         cprintf("%s\n", config.c_nodename);
 251         cprintf("%s\n", config.c_humannode);
 252         cprintf("%s\n", config.c_fqdn);
 253         cprintf("%s\n", CITADEL);
 254         cprintf("%d\n", REV_LEVEL);
 255         cprintf("%s\n", config.c_site_location);
 256         cprintf("%s\n", config.c_sysadm);
 257         cprintf("%d\n", SERVER_TYPE);
 258         cprintf("%s\n", config.c_moreprompt);
 259         cprintf("1\n"); /* 1 = yes, this system supports floors */
 260         cprintf("1\n"); /* 1 = we support the extended paging options */
 261         cprintf("%s\n", CC->cs_nonce);
 262         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 263
 264 #ifdef HAVE_LDAP
 265         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
 266 #else
 267         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
 268 #endif
 269
 270         if (config.c_auth_mode == 1) {
 271                 cprintf("1\n"); /* "create new user" never works with host auth */
 272         }
 273         else {
 274                 cprintf("%d\n", config.c_disable_newu); /* otherwise, site defined */
 275         }
 276
 277         cprintf("%s\n", config.c_default_cal_zone);
 278
 279         cprintf("000\n");
 280 }
 281
 282
 283 /*
 284  * returns an asterisk if there are any instant messages waiting,
 285  * space otherwise.
 286  */
 287 char CtdlCheckExpress(void) {
 288         if (CC->FirstExpressMessage == NULL) {
 289                 return(' ');
 290         }
 291         else {
 292                 return('*');
 293         }
 294 }
 295
 296 void cmd_time(void)
 297 {
 298    time_t tv;
 299    struct tm tmp;
 300
 301    tv = time(NULL);
 302    localtime_r(&tv, &tmp);
 303
 304    /* timezone and daylight global variables are not portable. */
 305 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 306    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst);
 307 #else
 308    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst);
 309 #endif
 310 }
 311
 312
 313 /*
 314  * Check originating host against the public_clients file.  This determines
 315  * whether the client is allowed to change the hostname for this session
 316  * (for example, to show the location of the user rather than the location
 317  * of the client).
 318  */
 319 int is_public_client(void)
 320 {
 321         char buf[1024];
 322         char addrbuf[1024];
 323         FILE *fp;
 324         int i;
 325         struct stat statbuf;
 326         static time_t pc_timestamp = 0;
 327         static char public_clients[SIZ];
 328         static char public_clients_file[SIZ];
 329
 330         snprintf(public_clients_file,
 331                          sizeof public_clients_file,
 332                          "%s/public_clients",
 333                          ctdl_etc_dir);
 334
 335         /*
 336          * Check the time stamp on the public_clients file.  If it's been
 337          * updated since the last time we were here (or if this is the first
 338          * time we've been through the loop), read its contents and learn
 339          * the IP addresses of the listed hosts.
 340          */
 341         if (stat(public_clients_file, &statbuf) != 0) {
 342                 /* No public_clients file exists, so bail out */
 343                 lprintf(CTDL_WARNING, "Warning: '%s' does not exist\n",
 344                                 public_clients_file);
 345                 return(0);
 346         }
 347
 348         if (statbuf.st_mtime > pc_timestamp) {
 349                 begin_critical_section(S_PUBLIC_CLIENTS);
 350                 lprintf(CTDL_INFO, "Loading %s\n", public_clients_file);
 351
 352                 safestrncpy(public_clients, "127.0.0.1", sizeof public_clients);
 353                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 354                         strcat(public_clients, "|");
 355                         strcat(public_clients, addrbuf);
 356                 }
 357
 358                 fp = fopen(public_clients_file, "r");
 359                 if (fp != NULL) while (fgets(buf, sizeof buf, fp)!=NULL) {
 360                         for (i=0; i<strlen(buf); ++i) {
 361                                 if (buf[i] == '#') buf[i] = 0;
 362                         }
 363                         while (isspace((buf[strlen(buf)-1]))) {
 364                                 buf[strlen(buf)-1] = 0;
 365                         }
 366                         if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 367                                 if ((strlen(public_clients) +
 368                                    strlen(addrbuf) + 2)
 369                                    < sizeof(public_clients)) {
 370                                         strcat(public_clients, "|");
 371                                         strcat(public_clients, addrbuf);
 372                                 }
 373                         }
 374                 }
 375                 fclose(fp);
 376                 pc_timestamp = time(NULL);
 377                 end_critical_section(S_PUBLIC_CLIENTS);
 378         }
 379
 380         lprintf(CTDL_DEBUG, "Checking whether %s is a local or public client\n",
 381                 CC->cs_addr);
 382         for (i=0; i<num_parms(public_clients); ++i) {
 383                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 384                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 385                         lprintf(CTDL_DEBUG, "... yes it is.\n");
 386                         return(1);
 387                 }
 388         }
 389
 390         /* No hits.  This is not a public client. */
 391         lprintf(CTDL_DEBUG, "... no it isn't.\n");
 392         return(0);
 393 }
 394
 395
 396 /*
 397  * the client is identifying itself to the server
 398  */
 399 void cmd_iden(char *argbuf)
 400 {
 401         int dev_code;
 402         int cli_code;
 403         int rev_level;
 404         char desc[128];
 405         char from_host[128];
 406         struct in_addr addr;
 407         int do_lookup = 0;
 408
 409         if (num_parms(argbuf)<4) {
 410                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
 411                 return;
 412         }
 413
 414         dev_code = extract_int(argbuf,0);
 415         cli_code = extract_int(argbuf,1);
 416         rev_level = extract_int(argbuf,2);
 417         extract_token(desc, argbuf, 3, '|', sizeof desc);
 418
 419         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 420         from_host[sizeof from_host - 1] = 0;
 421         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
 422
 423         CC->cs_clientdev = dev_code;
 424         CC->cs_clienttyp = cli_code;
 425         CC->cs_clientver = rev_level;
 426         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 427         CC->cs_clientname[31] = 0;
 428
 429         if (strlen(from_host) > 0) {
 430                 if (CC->is_local_socket) do_lookup = 1;
 431                 else if (is_public_client()) do_lookup = 1;
 432         }
 433
 434         if (do_lookup) {
 435                 lprintf(CTDL_DEBUG, "Looking up hostname '%s'\n", from_host);
 436                 if ((addr.s_addr = inet_addr(from_host)) != -1) {
 437                         locate_host(CC->cs_host, sizeof CC->cs_host,
 438                                 NULL, 0,
 439                                 &addr);
 440                 }
 441                 else {
 442                         safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 443                         CC->cs_host[sizeof CC->cs_host - 1] = 0;
 444                 }
 445         }
 446
 447         lprintf(CTDL_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
 448                 dev_code,
 449                 cli_code,
 450                 (rev_level / 100),
 451                 (rev_level % 100),
 452                 desc,
 453                 CC->cs_host);
 454         cprintf("%d Ok\n",CIT_OK);
 455 }
 456
 457
 458 /*
 459  * display system messages or help
 460  */
 461 void cmd_mesg(char *mname)
 462 {
 463         FILE *mfp;
 464         char targ[256];
 465         char buf[256];
 466         char buf2[256];
 467         char *dirs[2];
 468         DIR *dp;
 469         struct dirent *d;
 470
 471         extract_token(buf, mname, 0, '|', sizeof buf);
 472
 473         dirs[0] = strdup(ctdl_message_dir);
 474         dirs[1] = strdup(ctdl_hlp_dir);
 475
 476         snprintf(buf2, sizeof buf2, "%s.%d.%d",
 477                 buf, CC->cs_clientdev, CC->cs_clienttyp);
 478
 479         /* If the client requested "?" then produce a listing */
 480         if (!strcmp(buf, "?")) {
 481                 cprintf("%d %s\n", LISTING_FOLLOWS, buf);
 482                 dp = opendir(dirs[1]);
 483                 if (dp != NULL) {
 484                         while (d = readdir(dp), d != NULL) {
 485                                 if (d->d_name[0] != '.') {
 486                                         cprintf(" %s\n", d->d_name);
 487                                 }
 488                         }
 489                         closedir(dp);
 490                 }
 491                 cprintf("000\n");
 492                 free(dirs[0]);
 493                 free(dirs[1]);
 494                 return;
 495         }
 496
 497         /* Otherwise, look for the requested file by name. */
 498         else {
 499                 mesg_locate(targ, sizeof targ, buf2, 2, (const char **)dirs);
 500                 if (strlen(targ) == 0) {
 501                         snprintf(buf2, sizeof buf2, "%s.%d",
 502                                                         buf, CC->cs_clientdev);
 503                         mesg_locate(targ, sizeof targ, buf2, 2,
 504                                                         (const char **)dirs);
 505                         if (strlen(targ) == 0) {
 506                                 mesg_locate(targ, sizeof targ, buf, 2,
 507                                                         (const char **)dirs);
 508                         }
 509                 }
 510         }
 511
 512         free(dirs[0]);
 513         free(dirs[1]);
 514
 515         if (strlen(targ)==0) {
 516                 cprintf("%d '%s' not found.  (Searching in %s and %s)\n",
 517                         ERROR + FILE_NOT_FOUND,
 518                         mname,
 519                         ctdl_message_dir,
 520                         ctdl_hlp_dir
 521                 );
 522                 return;
 523         }
 524
 525         mfp = fopen(targ, "r");
 526         if (mfp==NULL) {
 527                 cprintf("%d Cannot open '%s': %s\n",
 528                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 529                 return;
 530         }
 531         cprintf("%d %s\n", LISTING_FOLLOWS,buf);
 532
 533         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
 534                 buf[strlen(buf)-1] = 0;
 535                 do_help_subst(buf);
 536                 cprintf("%s\n",buf);
 537         }
 538
 539         fclose(mfp);
 540         cprintf("000\n");
 541 }
 542
 543
 544 /*
 545  * enter system messages or help
 546  */
 547 void cmd_emsg(char *mname)
 548 {
 549         FILE *mfp;
 550         char targ[256];
 551         char buf[256];
 552         char *dirs[2];
 553         int a;
 554
 555         unbuffer_output();
 556
 557         if (CtdlAccessCheck(ac_aide)) return;
 558
 559         extract_token(buf, mname, 0, '|', sizeof buf);
 560         for (a=0; a<strlen(buf); ++a) {         /* security measure */
 561                 if (buf[a] == '/') buf[a] = '.';
 562         }
 563
 564         dirs[0] = strdup(ctdl_message_dir);
 565         dirs[1] = strdup(ctdl_hlp_dir);
 566
 567         mesg_locate(targ, sizeof targ, buf, 2, (const char**)dirs);
 568         free(dirs[0]);
 569         free(dirs[1]);
 570
 571         if (strlen(targ)==0) {
 572                 snprintf(targ, sizeof targ,
 573                                  "%s/%s",
 574                                  ctdl_hlp_dir, buf);
 575         }
 576
 577         mfp = fopen(targ,"w");
 578         if (mfp==NULL) {
 579                 cprintf("%d Cannot open '%s': %s\n",
 580                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 581                 return;
 582         }
 583         cprintf("%d %s\n", SEND_LISTING, targ);
 584
 585         while (client_getln(buf, sizeof buf), strcmp(buf, "000")) {
 586                 fprintf(mfp, "%s\n", buf);
 587         }
 588
 589         fclose(mfp);
 590 }
 591
 592
 593 /* Don't show the names of private rooms unless the viewing
 594  * user also knows the rooms.
 595  */
 596 void GenerateRoomDisplay(char *real_room,
 597                         struct CitContext *viewed,
 598                         struct CitContext *viewer) {
 599
 600         int ra;
 601
 602         strcpy(real_room, viewed->room.QRname);
 603         if (viewed->room.QRflags & QR_MAILBOX) {
 604                 strcpy(real_room, &real_room[11]);
 605         }
 606         if (viewed->room.QRflags & QR_PRIVATE) {
 607                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
 608                 if ( (ra & UA_KNOWN) == 0) {
 609                         strcpy(real_room, "<private room>");
 610                 }
 611         }
 612
 613         if (viewed->cs_flags & CS_CHAT) {
 614                 while (strlen(real_room) < 14)
 615                         strcat(real_room, " ");
 616
 617                 strcpy(&real_room[14], "<chat>");
 618         }
 619
 620 }
 621
 622 /*
 623  * Convenience function.
 624  */
 625 int CtdlAccessCheck(int required_level) {
 626
 627         if (CC->internal_pgm) return(0);
 628         if (required_level >= ac_internal) {
 629                 cprintf("%d This is not a user-level command.\n",
 630                         ERROR + HIGHER_ACCESS_REQUIRED);
 631                 return(-1);
 632         }
 633
 634         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
 635                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 636                 return(-1);
 637         }
 638
 639         if (CC->user.axlevel >= 6) return(0);
 640         if (required_level >= ac_aide) {
 641                 cprintf("%d This command requires Aide access.\n",
 642                         ERROR + HIGHER_ACCESS_REQUIRED);
 643                 return(-1);
 644         }
 645
 646         if (is_room_aide()) return(0);
 647         if (required_level >= ac_room_aide) {
 648                 cprintf("%d This command requires Aide or Room Aide access.\n",
 649                         ERROR + HIGHER_ACCESS_REQUIRED);
 650                 return(-1);
 651         }
 652
 653         /* shhh ... succeed quietly */
 654         return(0);
 655 }
 656
 657
 658
 659 /*
 660  * Terminate another running session
 661  */
 662 void cmd_term(char *cmdbuf)
 663 {
 664         int session_num;
 665         struct CitContext *ccptr;
 666         int found_it = 0;
 667         int allowed = 0;
 668
 669         session_num = extract_int(cmdbuf, 0);
 670         if (session_num == CC->cs_pid) {
 671                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
 672                 return;
 673         }
 674
 675         lprintf(CTDL_DEBUG, "Locating session to kill\n");
 676         begin_critical_section(S_SESSION_TABLE);
 677         for (ccptr = ContextList; ccptr != NULL; ccptr = ccptr->next) {
 678                 if (session_num == ccptr->cs_pid) {
 679                         found_it = 1;
 680                         if ((ccptr->user.usernum == CC->user.usernum)
 681                            || (CC->user.axlevel >= 6)) {
 682                                 allowed = 1;
 683                                 ccptr->kill_me = 1;
 684                         }
 685                         else {
 686                                 allowed = 0;
 687                         }
 688                 }
 689         }
 690         end_critical_section(S_SESSION_TABLE);
 691
 692         if (found_it) {
 693                 if (allowed) {
 694                         cprintf("%d Session terminated.\n", CIT_OK);
 695                 }
 696                 else {
 697                         cprintf("%d You are not allowed to do that.\n",
 698                                 ERROR + HIGHER_ACCESS_REQUIRED);
 699                 }
 700         }
 701         else {
 702                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
 703         }
 704 }
 705
 706
 707
 708
 709
 710 /*
 711  * get the paginator prompt
 712  */
 713 void cmd_more(void) {
 714         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 715 }
 716
 717 /*
 718  * echo
 719  */
 720 void cmd_echo(char *etext)
 721 {
 722         cprintf("%d %s\n", CIT_OK, etext);
 723 }
 724
 725
 726
 727 /*
 728  * identify as internal program
 729  */
 730 void cmd_ipgm(char *argbuf)
 731 {
 732         int secret;
 733
 734         secret = extract_int(argbuf, 0);
 735
 736         /* For security reasons, we do NOT allow this command to run
 737          * over the network.  Local sockets only.
 738          */
 739         if (!CC->is_local_socket) {
 740                 sleep(5);
 741                 cprintf("%d Authentication failed.\n",
 742                         ERROR + PASSWORD_REQUIRED);
 743         }
 744         else if (secret == config.c_ipgm_secret) {
 745                 CC->internal_pgm = 1;
 746                 strcpy(CC->curr_user, "<internal program>");
 747                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 748                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
 749         }
 750         else {
 751                 sleep(5);
 752                 cprintf("%d Authentication failed.\n",
 753                         ERROR + PASSWORD_REQUIRED);
 754                 lprintf(CTDL_ERR, "Warning: ipgm authentication failed.\n");
 755                 CC->kill_me = 1;
 756         }
 757
 758         /* Now change the ipgm secret for the next round.
 759          * (Disabled because it breaks concurrent scripts.  The fact that
 760          * we no longer accept IPGM over the network should be sufficient
 761          * to prevent brute-force attacks.  If you don't agree, uncomment
 762          * this block.)
 763         get_config();
 764         config.c_ipgm_secret = rand();
 765         put_config();
 766         */
 767 }
 768
 769
 770 /*
 771  * Shut down the server
 772  */
 773 void cmd_down(void) {
 774
 775         if (CtdlAccessCheck(ac_aide)) return;
 776
 777         cprintf("%d Shutting down server.  Goodbye.\n", CIT_OK);
 778         time_to_die = 1;
 779 }
 780
 781 /*
 782  * Halt the server without exiting the server process.
 783  */
 784 void cmd_halt(void) {
 785
 786         if (CtdlAccessCheck(ac_aide)) return;
 787
 788         cprintf("%d Halting server.  Goodbye.\n", CIT_OK);
 789         time_to_die = 1;
 790         shutdown_and_halt = 1;
 791 }
 792
 793 /*
 794  * Schedule or cancel a server shutdown
 795  */
 796 void cmd_scdn(char *argbuf)
 797 {
 798         int new_state;
 799
 800         if (CtdlAccessCheck(ac_aide)) return;
 801
 802         new_state = extract_int(argbuf, 0);
 803         if ((new_state == 0) || (new_state == 1)) {
 804                 ScheduledShutdown = new_state;
 805         }
 806         cprintf("%d %d\n", CIT_OK, ScheduledShutdown);
 807 }
 808
 809
 810 /*
 811  * Set or unset asynchronous protocol mode
 812  */
 813 void cmd_asyn(char *argbuf)
 814 {
 815         int new_state;
 816
 817         new_state = extract_int(argbuf, 0);
 818         if ((new_state == 0) || (new_state == 1)) {
 819                 CC->is_async = new_state;
 820         }
 821         cprintf("%d %d\n", CIT_OK, CC->is_async);
 822 }
 823
 824
 825 /*
 826  * Generate a "nonce" for APOP-style authentication.
 827  *
 828  * RFC 1725 et al specify a PID to be placed in front of the nonce.
 829  * Quoth BTX: That would be stupid.
 830  */
 831 void generate_nonce(struct CitContext *con) {
 832         struct timeval tv;
 833
 834         memset(con->cs_nonce, NONCE_SIZE, 0);
 835         gettimeofday(&tv, NULL);
 836         memset(con->cs_nonce, NONCE_SIZE, 0);
 837         snprintf(con->cs_nonce, NONCE_SIZE, "<%d%ld@%s>",
 838                 rand(), (long)tv.tv_usec, config.c_fqdn);
 839 }
 840
 841
 842
 843
 844 /*
 845  * Back-end function for starting a session
 846  */
 847 void begin_session(struct CitContext *con)
 848 {
 849         socklen_t len;
 850         struct sockaddr_in sin;
 851
 852         /*
 853          * Initialize some variables specific to our context.
 854          */
 855         con->logged_in = 0;
 856         con->internal_pgm = 0;
 857         con->download_fp = NULL;
 858         con->upload_fp = NULL;
 859         con->FirstExpressMessage = NULL;
 860         time(&con->lastcmd);
 861         time(&con->lastidle);
 862         strcpy(con->lastcmdname, "    ");
 863         strcpy(con->cs_clientname, "(unknown)");
 864         strcpy(con->curr_user, NLI);
 865         strcpy(con->net_node, "");
 866         strcpy(con->fake_username, "");
 867         strcpy(con->fake_postname, "");
 868         strcpy(con->fake_hostname, "");
 869         strcpy(con->fake_roomname, "");
 870         generate_nonce(con);
 871         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 872         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 873         con->cs_host[sizeof con->cs_host - 1] = 0;
 874         len = sizeof sin;
 875         if (!CC->is_local_socket) {
 876                 if (!getpeername(con->client_socket, (struct sockaddr *) &sin, &len)) {
 877                         locate_host(con->cs_host, sizeof con->cs_host,
 878                                 con->cs_addr, sizeof con->cs_addr,
 879                                 &sin.sin_addr
 880                         );
 881                 }
 882         }
 883         else {
 884                 strcpy(con->cs_host, "");
 885         }
 886         con->cs_flags = 0;
 887         con->upload_type = UPL_FILE;
 888         con->dl_is_net = 0;
 889
 890         con->nologin = 0;
 891         if ((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions))
 892                 con->nologin = 1;
 893
 894         lprintf(CTDL_NOTICE, "Session started.\n");
 895
 896         /* Run any session startup routines registered by loadable modules */
 897         PerformSessionHooks(EVT_START);
 898 }
 899
 900
 901 void citproto_begin_session() {
 902         if (CC->nologin==1) {
 903                 cprintf("%d %s: Too many users are already online "
 904                         "(maximum is %d)\n",
 905                         ERROR + MAX_SESSIONS_EXCEEDED,
 906                         config.c_nodename, config.c_maxsessions);
 907         }
 908         else {
 909                 cprintf("%d %s Citadel server ready.\n",
 910                         CIT_OK, config.c_nodename);
 911         }
 912 }
 913
 914
 915
 916
 917 /*
 918  * This loop recognizes all server commands.
 919  */
 920 void do_command_loop(void) {
 921         char cmdbuf[SIZ];
 922
 923         time(&CC->lastcmd);
 924         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 925         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
 926                 lprintf(CTDL_ERR, "Client disconnected: ending session.\n");
 927                 CC->kill_me = 1;
 928                 return;
 929         }
 930
 931         /* Log the server command, but don't show passwords... */
 932         if ( (strncasecmp(cmdbuf, "PASS", 4))
 933            && (strncasecmp(cmdbuf, "SETP", 4)) ) {
 934                 lprintf(CTDL_INFO, "%s\n", cmdbuf);
 935         }
 936         else {
 937                 lprintf(CTDL_INFO, "<password command sent>\n");
 938         }
 939
 940         buffer_output();
 941
 942         /*
 943          * Let other clients see the last command we executed, and
 944          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
 945          */
 946         if ( (strncasecmp(cmdbuf, "NOOP", 4))
 947            && (strncasecmp(cmdbuf, "QNOP", 4))
 948            && (strncasecmp(cmdbuf, "PEXP", 4))
 949            && (strncasecmp(cmdbuf, "GEXP", 4))
 950            && (strncasecmp(cmdbuf, "RWHO", 4))
 951            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
 952                 strcpy(CC->lastcmdname, "    ");
 953                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
 954                 time(&CC->lastidle);
 955         }
 956
 957         if ((strncasecmp(cmdbuf, "ENT0", 4))
 958            && (strncasecmp(cmdbuf, "MESG", 4))
 959            && (strncasecmp(cmdbuf, "MSGS", 4)))
 960         {
 961            CC->cs_flags &= ~CS_POSTING;
 962         }
 963
 964         if (!strncasecmp(cmdbuf, "NOOP", 4)) {
 965                 cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
 966         }
 967
 968         else if (!strncasecmp(cmdbuf, "QNOP", 4)) {
 969                 /* do nothing, this command returns no response */
 970         }
 971
 972         else if (!strncasecmp(cmdbuf,"QUIT",4)) {
 973                 cprintf("%d Goodbye.\n", CIT_OK);
 974                 CC->kill_me = 1;
 975         }
 976
 977         else if (!strncasecmp(cmdbuf,"ASYN",4)) {
 978                 cmd_asyn(&cmdbuf[5]);
 979         }
 980
 981         else if (!strncasecmp(cmdbuf,"LOUT",4)) {
 982                 if (CC->logged_in) logout(CC);
 983                 cprintf("%d logged out.\n", CIT_OK);
 984         }
 985
 986         else if (!strncasecmp(cmdbuf,"USER",4)) {
 987                 cmd_user(&cmdbuf[5]);
 988         }
 989
 990         else if (!strncasecmp(cmdbuf,"PASS",4)) {
 991                 cmd_pass(&cmdbuf[5]);
 992         }
 993
 994         else if (!strncasecmp(cmdbuf,"NEWU",4)) {
 995                 cmd_newu(&cmdbuf[5]);
 996         }
 997
 998         else if (!strncasecmp(cmdbuf,"CREU",4)) {
 999                 cmd_creu(&cmdbuf[5]);
1000         }
1001
1002         else if (!strncasecmp(cmdbuf,"SETP",4)) {
1003                 cmd_setp(&cmdbuf[5]);
1004         }
1005
1006         else if (!strncasecmp(cmdbuf,"LRMS",4)) {
1007                 cmd_lrms(&cmdbuf[5]);
1008         }
1009
1010         else if (!strncasecmp(cmdbuf,"LKRA",4)) {
1011                 cmd_lkra(&cmdbuf[5]);
1012         }
1013
1014         else if (!strncasecmp(cmdbuf,"LKRN",4)) {
1015                 cmd_lkrn(&cmdbuf[5]);
1016         }
1017
1018         else if (!strncasecmp(cmdbuf,"LKRO",4)) {
1019                 cmd_lkro(&cmdbuf[5]);
1020         }
1021
1022         else if (!strncasecmp(cmdbuf,"LZRM",4)) {
1023                 cmd_lzrm(&cmdbuf[5]);
1024         }
1025
1026         else if (!strncasecmp(cmdbuf,"LPRM",4)) {
1027                 cmd_lprm(&cmdbuf[5]);
1028         }
1029
1030         else if (!strncasecmp(cmdbuf,"GETU",4)) {
1031                 cmd_getu();
1032         }
1033
1034         else if (!strncasecmp(cmdbuf,"SETU",4)) {
1035                 cmd_setu(&cmdbuf[5]);
1036         }
1037
1038         else if (!strncasecmp(cmdbuf,"GOTO",4)) {
1039                 cmd_goto(&cmdbuf[5]);
1040         }
1041
1042         else if (!strncasecmp(cmdbuf,"MSGS",4)) {
1043                 cmd_msgs(&cmdbuf[5]);
1044         }
1045
1046         else if (!strncasecmp(cmdbuf,"WHOK",4)) {
1047                 cmd_whok();
1048         }
1049
1050         else if (!strncasecmp(cmdbuf,"RDIR",4)) {
1051                 cmd_rdir();
1052         }
1053
1054         else if (!strncasecmp(cmdbuf,"EUID",4)) {
1055                 cmd_euid(&cmdbuf[5]);
1056         }
1057
1058         else if (!strncasecmp(cmdbuf,"MSG0",4)) {
1059                 cmd_msg0(&cmdbuf[5]);
1060         }
1061
1062         else if (!strncasecmp(cmdbuf,"MSG2",4)) {
1063                 cmd_msg2(&cmdbuf[5]);
1064         }
1065
1066         else if (!strncasecmp(cmdbuf,"MSG3",4)) {
1067                 cmd_msg3(&cmdbuf[5]);
1068         }
1069
1070         else if (!strncasecmp(cmdbuf,"MSG4",4)) {
1071                 cmd_msg4(&cmdbuf[5]);
1072         }
1073
1074         else if (!strncasecmp(cmdbuf,"MSGP",4)) {
1075                 cmd_msgp(&cmdbuf[5]);
1076         }
1077
1078         else if (!strncasecmp(cmdbuf,"OPNA",4)) {
1079                 cmd_opna(&cmdbuf[5]);
1080         }
1081
1082         else if (!strncasecmp(cmdbuf,"DLAT",4)) {
1083                 cmd_dlat(&cmdbuf[5]);
1084         }
1085
1086         else if (!strncasecmp(cmdbuf,"INFO",4)) {
1087                 cmd_info();
1088         }
1089
1090         else if (!strncasecmp(cmdbuf,"SLRP",4)) {
1091                 cmd_slrp(&cmdbuf[5]);
1092         }
1093
1094         else if (!strncasecmp(cmdbuf,"INVT",4)) {
1095                 cmd_invt_kick(&cmdbuf[5],1);
1096         }
1097
1098         else if (!strncasecmp(cmdbuf,"KICK",4)) {
1099                 cmd_invt_kick(&cmdbuf[5],0);
1100         }
1101
1102         else if (!strncasecmp(cmdbuf,"GETR",4)) {
1103                 cmd_getr();
1104         }
1105
1106         else if (!strncasecmp(cmdbuf,"SETR",4)) {
1107                 cmd_setr(&cmdbuf[5]);
1108         }
1109
1110         else if (!strncasecmp(cmdbuf,"GETA",4)) {
1111                 cmd_geta();
1112         }
1113
1114         else if (!strncasecmp(cmdbuf,"SETA",4)) {
1115                 cmd_seta(&cmdbuf[5]);
1116         }
1117
1118         else if (!strncasecmp(cmdbuf,"ENT0",4)) {
1119                 cmd_ent0(&cmdbuf[5]);
1120         }
1121
1122         else if (!strncasecmp(cmdbuf,"RINF",4)) {
1123                 cmd_rinf();
1124         }
1125
1126         else if (!strncasecmp(cmdbuf,"DELE",4)) {
1127                 cmd_dele(&cmdbuf[5]);
1128         }
1129
1130         else if (!strncasecmp(cmdbuf,"KILL",4)) {
1131                 cmd_kill(&cmdbuf[5]);
1132         }
1133
1134         else if (!strncasecmp(cmdbuf,"CRE8",4)) {
1135                 cmd_cre8(&cmdbuf[5]);
1136         }
1137
1138         else if (!strncasecmp(cmdbuf,"MOVE",4)) {
1139                 cmd_move(&cmdbuf[5]);
1140         }
1141
1142         else if (!strncasecmp(cmdbuf,"FORG",4)) {
1143                 cmd_forg();
1144         }
1145
1146         else if (!strncasecmp(cmdbuf,"MESG",4)) {
1147                 cmd_mesg(&cmdbuf[5]);
1148         }
1149
1150         else if (!strncasecmp(cmdbuf,"EMSG",4)) {
1151                 cmd_emsg(&cmdbuf[5]);
1152         }
1153
1154         else if (!strncasecmp(cmdbuf,"GNUR",4)) {
1155                 cmd_gnur();
1156         }
1157
1158         else if (!strncasecmp(cmdbuf,"VALI",4)) {
1159                 cmd_vali(&cmdbuf[5]);
1160         }
1161
1162         else if (!strncasecmp(cmdbuf,"EINF",4)) {
1163                 cmd_einf(&cmdbuf[5]);
1164         }
1165
1166         else if (!strncasecmp(cmdbuf,"LIST",4)) {
1167                 cmd_list(&cmdbuf[5]);
1168         }
1169
1170         else if (!strncasecmp(cmdbuf,"CHEK",4)) {
1171                 cmd_chek();
1172         }
1173
1174         else if (!strncasecmp(cmdbuf,"DELF",4)) {
1175                 cmd_delf(&cmdbuf[5]);
1176         }
1177
1178         else if (!strncasecmp(cmdbuf,"MOVF",4)) {
1179                 cmd_movf(&cmdbuf[5]);
1180         }
1181
1182         else if (!strncasecmp(cmdbuf,"NETF",4)) {
1183                 cmd_netf(&cmdbuf[5]);
1184         }
1185
1186         else if (!strncasecmp(cmdbuf,"OPEN",4)) {
1187                 cmd_open(&cmdbuf[5]);
1188         }
1189
1190         else if (!strncasecmp(cmdbuf,"CLOS",4)) {
1191                 cmd_clos();
1192         }
1193
1194         else if (!strncasecmp(cmdbuf,"UOPN",4)) {
1195                 cmd_uopn(&cmdbuf[5]);
1196         }
1197
1198         else if (!strncasecmp(cmdbuf,"UCLS",4)) {
1199                 cmd_ucls(&cmdbuf[5]);
1200         }
1201
1202         else if (!strncasecmp(cmdbuf,"READ",4)) {
1203                 cmd_read(&cmdbuf[5]);
1204         }
1205
1206         else if (!strncasecmp(cmdbuf,"WRIT",4)) {
1207                 cmd_writ(&cmdbuf[5]);
1208         }
1209
1210         else if (!strncasecmp(cmdbuf,"QUSR",4)) {
1211                 cmd_qusr(&cmdbuf[5]);
1212         }
1213
1214         else if (!strncasecmp(cmdbuf,"ECHO",4)) {
1215                 cmd_echo(&cmdbuf[5]);
1216         }
1217
1218         else if (!strncasecmp(cmdbuf,"OIMG",4)) {
1219                 cmd_oimg(&cmdbuf[5]);
1220         }
1221
1222         else if (!strncasecmp(cmdbuf,"MORE",4)) {
1223                 cmd_more();
1224         }
1225
1226         else if (!strncasecmp(cmdbuf,"NDOP",4)) {
1227                 cmd_ndop(&cmdbuf[5]);
1228         }
1229
1230         else if (!strncasecmp(cmdbuf,"NUOP",4)) {
1231                 cmd_nuop(&cmdbuf[5]);
1232         }
1233
1234         else if (!strncasecmp(cmdbuf,"LFLR",4)) {
1235                 cmd_lflr();
1236         }
1237
1238         else if (!strncasecmp(cmdbuf,"CFLR",4)) {
1239                 cmd_cflr(&cmdbuf[5]);
1240         }
1241
1242         else if (!strncasecmp(cmdbuf,"KFLR",4)) {
1243                 cmd_kflr(&cmdbuf[5]);
1244         }
1245
1246         else if (!strncasecmp(cmdbuf,"EFLR",4)) {
1247                 cmd_eflr(&cmdbuf[5]);
1248         }
1249
1250         else if (!strncasecmp(cmdbuf,"IDEN",4)) {
1251                 cmd_iden(&cmdbuf[5]);
1252         }
1253
1254         else if (!strncasecmp(cmdbuf,"IPGM",4)) {
1255                 cmd_ipgm(&cmdbuf[5]);
1256         }
1257
1258         else if (!strncasecmp(cmdbuf,"TERM",4)) {
1259                 cmd_term(&cmdbuf[5]);
1260         }
1261
1262         else if (!strncasecmp(cmdbuf,"DOWN",4)) {
1263                 cmd_down();
1264         }
1265
1266         else if (!strncasecmp(cmdbuf,"HALT",4)) {
1267                 cmd_halt();
1268         }
1269
1270         else if (!strncasecmp(cmdbuf,"SCDN",4)) {
1271                 cmd_scdn(&cmdbuf[5]);
1272         }
1273
1274         else if (!strncasecmp(cmdbuf, "UIMG", 4)) {
1275                 cmd_uimg(&cmdbuf[5]);
1276         }
1277
1278         else if (!strncasecmp(cmdbuf, "TIME", 4)) {
1279                 cmd_time();
1280         }
1281
1282         else if (!strncasecmp(cmdbuf, "AGUP", 4)) {
1283                 cmd_agup(&cmdbuf[5]);
1284         }
1285
1286         else if (!strncasecmp(cmdbuf, "ASUP", 4)) {
1287                 cmd_asup(&cmdbuf[5]);
1288         }
1289
1290         else if (!strncasecmp(cmdbuf, "GPEX", 4)) {
1291                 cmd_gpex(&cmdbuf[5]);
1292         }
1293
1294         else if (!strncasecmp(cmdbuf, "SPEX", 4)) {
1295                 cmd_spex(&cmdbuf[5]);
1296         }
1297
1298         else if (!strncasecmp(cmdbuf, "CONF", 4)) {
1299                 cmd_conf(&cmdbuf[5]);
1300         }
1301
1302         else if (!strncasecmp(cmdbuf, "SEEN", 4)) {
1303                 cmd_seen(&cmdbuf[5]);
1304         }
1305
1306         else if (!strncasecmp(cmdbuf, "GTSN", 4)) {
1307                 cmd_gtsn(&cmdbuf[5]);
1308         }
1309
1310         else if (!strncasecmp(cmdbuf, "VIEW", 4)) {
1311                 cmd_view(&cmdbuf[5]);
1312         }
1313
1314         else if (!strncasecmp(cmdbuf, "ISME", 4)) {
1315                 cmd_isme(&cmdbuf[5]);
1316         }
1317
1318         else if (!DLoader_Exec_Cmd(cmdbuf)) {
1319                 cprintf("%d Unrecognized or unsupported command.\n",
1320                         ERROR + CMD_NOT_SUPPORTED);
1321                }
1322
1323         unbuffer_output();
1324
1325         /* Run any after-each-command routines registered by modules */
1326         PerformSessionHooks(EVT_CMD);
1327 }
1328
1329
1330 /*
1331  * This loop performs all asynchronous functions.
1332  */
1333 void do_async_loop(void) {
1334         PerformSessionHooks(EVT_ASYNC);
1335 }