citadel/citserver.c

   1 /*
   2  * $Id$
   3  *
   4  * Main source module for the Citadel server
   5  *
   6  * Copyright (c) 1987-2009 by the citadel.org team
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 3 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include "sysdep.h"
  24 #include <stdlib.h>
  25 #include <unistd.h>
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include <signal.h>
  29 #include <sys/types.h>
  30 #include <sys/stat.h>
  31
  32
  33 #if TIME_WITH_SYS_TIME
  34 # include <sys/time.h>
  35 # include <time.h>
  36 #else
  37 # if HAVE_SYS_TIME_H
  38 #  include <sys/time.h>
  39 # else
  40 #  include <time.h>
  41 # endif
  42 #endif
  43
  44 #if HAVE_BACKTRACE
  45 #include <execinfo.h>
  46 #endif
  47
  48 #include <ctype.h>
  49 #include <string.h>
  50 #include <dirent.h>
  51 #include <errno.h>
  52 #include <limits.h>
  53 #include <netdb.h>
  54 #include <sys/types.h>
  55 #include <sys/socket.h>
  56 #include <netinet/in.h>
  57 #include <arpa/inet.h>
  58 #include <libcitadel.h>
  59 #include "citadel.h"
  60 #include "server.h"
  61 #include "sysdep_decls.h"
  62 #include "threads.h"
  63 #include "citserver.h"
  64 #include "config.h"
  65 #include "database.h"
  66 #include "housekeeping.h"
  67 #include "user_ops.h"
  68 #include "msgbase.h"
  69 #include "support.h"
  70 #include "locate_host.h"
  71 #include "room_ops.h"
  72 #include "file_ops.h"
  73 #include "policy.h"
  74 #include "control.h"
  75 #include "euidindex.h"
  76 #include "context.h"
  77 #include "svn_revision.h"
  78
  79 #ifndef HAVE_SNPRINTF
  80 #include "snprintf.h"
  81 #endif
  82
  83 #include "ctdl_module.h"
  84
  85
  86 char *unique_session_numbers;
  87 int ScheduledShutdown = 0;
  88 time_t server_startup_time;
  89 int panic_fd;
  90
  91 /*
  92  * print the actual stack frame.
  93  */
  94 void cit_backtrace(void)
  95 {
  96 #ifdef HAVE_BACKTRACE
  97         void *stack_frames[50];
  98         size_t size, i;
  99         char **strings;
 100
 101
 102         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 103         strings = backtrace_symbols(stack_frames, size);
 104         for (i = 0; i < size; i++) {
 105                 if (strings != NULL)
 106                         CtdlLogPrintf(1, "%s\n", strings[i]);
 107                 else
 108                         CtdlLogPrintf(1, "%p\n", stack_frames[i]);
 109         }
 110         free(strings);
 111 #endif
 112 }
 113
 114 /*
 115  * print the actual stack frame.
 116  */
 117 void cit_panic_backtrace(int SigNum)
 118 {
 119 #ifdef HAVE_BACKTRACE
 120         void *stack_frames[10];
 121         size_t size, i;
 122         char **strings;
 123
 124         printf("caught signal 11\n");
 125         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 126         strings = backtrace_symbols(stack_frames, size);
 127         for (i = 0; i < size; i++) {
 128                 if (strings != NULL)
 129                         CtdlLogPrintf(1, "%s\n", strings[i]);
 130                 else
 131                         CtdlLogPrintf(1, "%p\n", stack_frames[i]);
 132         }
 133         free(strings);
 134 #endif
 135         exit(-1);
 136 }
 137
 138 /*
 139  * Various things that need to be initialized at startup
 140  */
 141 void master_startup(void) {
 142         struct timeval tv;
 143         unsigned int seed;
 144         FILE *urandom;
 145         struct ctdlroom qrbuf;
 146         int rv;
 147
 148         CtdlLogPrintf(CTDL_DEBUG, "master_startup() started\n");
 149         time(&server_startup_time);
 150
 151         CtdlLogPrintf(CTDL_INFO, "Opening databases\n");
 152         open_databases();
 153
 154         ctdl_thread_internal_init_tsd();
 155
 156         CtdlThreadAllocTSD();
 157
 158         check_ref_counts();
 159
 160         CtdlLogPrintf(CTDL_INFO, "Creating base rooms (if necessary)\n");
 161         CtdlCreateRoom(config.c_baseroom,       0, "", 0, 1, 0, VIEW_BBS);
 162         CtdlCreateRoom(AIDEROOM,                3, "", 0, 1, 0, VIEW_BBS);
 163         CtdlCreateRoom(SYSCONFIGROOM,           3, "", 0, 1, 0, VIEW_BBS);
 164         CtdlCreateRoom(config.c_twitroom,       0, "", 0, 1, 0, VIEW_BBS);
 165
 166         /* The "Local System Configuration" room doesn't need to be visible */
 167         if (CtdlGetRoomLock(&qrbuf, SYSCONFIGROOM) == 0) {
 168                 qrbuf.QRflags2 |= QR2_SYSTEM;
 169                 CtdlPutRoomLock(&qrbuf);
 170         }
 171
 172         /* Aide needs to be public postable, else we're not RFC conformant. */
 173         if (CtdlGetRoomLock(&qrbuf, AIDEROOM) == 0) {
 174                 qrbuf.QRflags2 |= QR2_SMTP_PUBLIC;
 175                 CtdlPutRoomLock(&qrbuf);
 176         }
 177
 178         CtdlLogPrintf(CTDL_INFO, "Seeding the pseudo-random number generator...\n");
 179         urandom = fopen("/dev/urandom", "r");
 180         if (urandom != NULL) {
 181                 rv = fread(&seed, sizeof seed, 1, urandom);
 182                 fclose(urandom);
 183         }
 184         else {
 185                 gettimeofday(&tv, NULL);
 186                 seed = tv.tv_usec;
 187         }
 188         srand(seed);
 189         srandom(seed);
 190
 191         CtdlLogPrintf(CTDL_INFO, "Initializing ipgm secret\n");
 192         get_config();
 193         config.c_ipgm_secret = rand();
 194         put_config();
 195
 196         CtdlLogPrintf(CTDL_DEBUG, "master_startup() finished\n");
 197 }
 198
 199
 200 /*
 201  * Cleanup routine to be called when the server is shutting down.
 202  */
 203 void master_cleanup(int exitcode) {
 204         struct CleanupFunctionHook *fcn;
 205         static int already_cleaning_up = 0;
 206
 207         if (already_cleaning_up) while(1) sleep(1);
 208         already_cleaning_up = 1;
 209
 210         /* Run any cleanup routines registered by loadable modules */
 211         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 212                 (*fcn->h_function_pointer)();
 213         }
 214
 215         /* Close the AdjRefCount queue file */
 216         AdjRefCount(-1, 0);
 217
 218         /* Do system-dependent stuff */
 219         sysdep_master_cleanup();
 220
 221         /* Close databases */
 222         CtdlLogPrintf(CTDL_INFO, "Closing databases\n");
 223         close_databases();
 224
 225 #ifdef DEBUG_MEMORY_LEAKS
 226         dump_heap();
 227 #endif
 228
 229         /* If the operator requested a halt but not an exit, halt here. */
 230         if (shutdown_and_halt) {
 231                 CtdlLogPrintf(CTDL_NOTICE, "citserver: Halting server without exiting.\n");
 232                 fflush(stdout); fflush(stderr);
 233                 while(1) {
 234                         sleep(32767);
 235                 }
 236         }
 237
 238         release_control();
 239
 240         /* Now go away. */
 241         CtdlLogPrintf(CTDL_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 242         fflush(stdout); fflush(stderr);
 243
 244         if (restart_server != 0)
 245                 exit(1);
 246         if ((running_as_daemon != 0) && (exitcode == 0))
 247                 exitcode = CTDLEXIT_SHUTDOWN;
 248         exit(exitcode);
 249 }
 250
 251
 252
 253 /*
 254  * cmd_info()  -  tell the client about this server
 255  */
 256 void cmd_info(char *cmdbuf) {
 257         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 258         cprintf("%d\n", CC->cs_pid);
 259         cprintf("%s\n", config.c_nodename);
 260         cprintf("%s\n", config.c_humannode);
 261         cprintf("%s\n", config.c_fqdn);
 262         cprintf("%s\n", CITADEL);
 263         cprintf("%d\n", REV_LEVEL);
 264         cprintf("%s\n", config.c_site_location);
 265         cprintf("%s\n", config.c_sysadm);
 266         cprintf("%d\n", SERVER_TYPE);
 267         cprintf("%s\n", config.c_moreprompt);
 268         cprintf("1\n"); /* 1 = yes, this system supports floors */
 269         cprintf("1\n"); /* 1 = we support the extended paging options */
 270         cprintf("%s\n", CC->cs_nonce);
 271         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 272
 273 #ifdef HAVE_LDAP
 274         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
 275 #else
 276         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
 277 #endif
 278
 279         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 280                 cprintf("%d\n", config.c_disable_newu);
 281         }
 282         else {
 283                 cprintf("1\n"); /* "create new user" does not work with non-native auth modes */
 284         }
 285
 286         cprintf("%s\n", config.c_default_cal_zone);
 287
 288         /* Output load averages */
 289         cprintf("%f\n", CtdlThreadLoadAvg);
 290         cprintf("%f\n", CtdlThreadWorkerAvg);
 291         cprintf("%d\n", CtdlThreadGetCount());
 292
 293         cprintf("1\n");         /* yes, Sieve mail filtering is supported */
 294         cprintf("%d\n", config.c_enable_fulltext);
 295         cprintf("%s\n", svn_revision());
 296
 297         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 298                 cprintf("1\n"); /* OpenID is enabled when using native auth */
 299         }
 300         else {
 301                 cprintf("0\n"); /* OpenID is disabled when using non-native auth */
 302         }
 303
 304         cprintf("000\n");
 305 }
 306
 307
 308 /*
 309  * returns an asterisk if there are any instant messages waiting,
 310  * space otherwise.
 311  */
 312 char CtdlCheckExpress(void) {
 313         if (CC->FirstExpressMessage == NULL) {
 314                 return(' ');
 315         }
 316         else {
 317                 return('*');
 318         }
 319 }
 320
 321 void cmd_time(char *argbuf)
 322 {
 323    time_t tv;
 324    struct tm tmp;
 325
 326    tv = time(NULL);
 327    localtime_r(&tv, &tmp);
 328
 329    /* timezone and daylight global variables are not portable. */
 330 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 331    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst);
 332 #else
 333    cprintf("%d %ld|%ld|%d\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst);
 334 #endif
 335 }
 336
 337
 338 /*
 339  * Check originating host against the public_clients file.  This determines
 340  * whether the client is allowed to change the hostname for this session
 341  * (for example, to show the location of the user rather than the location
 342  * of the client).
 343  */
 344 int is_public_client(void)
 345 {
 346         char buf[1024];
 347         char addrbuf[1024];
 348         FILE *fp;
 349         int i;
 350         char *public_clientspos;
 351         char *public_clientsend;
 352         char *paddr = NULL;
 353         struct stat statbuf;
 354         static time_t pc_timestamp = 0;
 355         static char public_clients[SIZ];
 356         static char public_clients_file[SIZ];
 357
 358 #define LOCALHOSTSTR "127.0.0.1"
 359
 360         snprintf(public_clients_file, sizeof public_clients_file, "%s/public_clients", ctdl_etc_dir);
 361
 362         /*
 363          * Check the time stamp on the public_clients file.  If it's been
 364          * updated since the last time we were here (or if this is the first
 365          * time we've been through the loop), read its contents and learn
 366          * the IP addresses of the listed hosts.
 367          */
 368         if (stat(public_clients_file, &statbuf) != 0) {
 369                 /* No public_clients file exists, so bail out */
 370                 CtdlLogPrintf(CTDL_WARNING, "Warning: '%s' does not exist\n",
 371                                 public_clients_file);
 372                 return(0);
 373         }
 374
 375         if (statbuf.st_mtime > pc_timestamp) {
 376                 begin_critical_section(S_PUBLIC_CLIENTS);
 377                 CtdlLogPrintf(CTDL_INFO, "Loading %s\n", public_clients_file);
 378
 379                 public_clientspos = &public_clients[0];
 380                 public_clientsend = public_clientspos + SIZ;
 381                 safestrncpy(public_clientspos, LOCALHOSTSTR, sizeof public_clients);
 382                 public_clientspos += sizeof(LOCALHOSTSTR) - 1;
 383
 384                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 385                         *(public_clientspos++) = '|';
 386                         paddr = &addrbuf[0];
 387                         while (!IsEmptyStr (paddr) &&
 388                                (public_clientspos < public_clientsend))
 389                                 *(public_clientspos++) = *(paddr++);
 390                 }
 391
 392                 fp = fopen(public_clients_file, "r");
 393                 if (fp != NULL)
 394                         while ((fgets(buf, sizeof buf, fp)!=NULL) &&
 395                                (public_clientspos < public_clientsend)){
 396                                 char *ptr;
 397                                 ptr = buf;
 398                                 while (!IsEmptyStr(ptr)) {
 399                                         if (*ptr == '#') {
 400                                                 *ptr = 0;
 401                                                 break;
 402                                         }
 403                                 else ptr++;
 404                                 }
 405                                 ptr--;
 406                                 while (ptr>buf && isspace(*ptr)) {
 407                                         *(ptr--) = 0;
 408                                 }
 409                                 if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 410                                         *(public_clientspos++) = '|';
 411                                         paddr = addrbuf;
 412                                         while (!IsEmptyStr(paddr) &&
 413                                                (public_clientspos < public_clientsend)){
 414                                                 *(public_clientspos++) = *(paddr++);
 415                                         }
 416                                 }
 417                         }
 418                 fclose(fp);
 419                 pc_timestamp = time(NULL);
 420                 end_critical_section(S_PUBLIC_CLIENTS);
 421         }
 422
 423         CtdlLogPrintf(CTDL_DEBUG, "Checking whether %s is a local or public client\n",
 424                 CC->cs_addr);
 425         for (i=0; i<num_parms(public_clients); ++i) {
 426                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 427                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 428                         CtdlLogPrintf(CTDL_DEBUG, "... yes it is.\n");
 429                         return(1);
 430                 }
 431         }
 432
 433         /* No hits.  This is not a public client. */
 434         CtdlLogPrintf(CTDL_DEBUG, "... no it isn't.\n");
 435         return(0);
 436 }
 437
 438
 439 /*
 440  * the client is identifying itself to the server
 441  */
 442 void cmd_iden(char *argbuf)
 443 {
 444         int dev_code;
 445         int cli_code;
 446         int rev_level;
 447         char desc[128];
 448         char from_host[128];
 449         struct in_addr addr;
 450         int do_lookup = 0;
 451
 452         if (num_parms(argbuf)<4) {
 453                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
 454                 return;
 455         }
 456
 457         dev_code = extract_int(argbuf,0);
 458         cli_code = extract_int(argbuf,1);
 459         rev_level = extract_int(argbuf,2);
 460         extract_token(desc, argbuf, 3, '|', sizeof desc);
 461
 462         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 463         from_host[sizeof from_host - 1] = 0;
 464         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
 465
 466         CC->cs_clientdev = dev_code;
 467         CC->cs_clienttyp = cli_code;
 468         CC->cs_clientver = rev_level;
 469         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 470         CC->cs_clientname[31] = 0;
 471
 472         if (!IsEmptyStr(from_host)) {
 473                 if (CC->is_local_socket) do_lookup = 1;
 474                 else if (is_public_client()) do_lookup = 1;
 475         }
 476
 477         if (do_lookup) {
 478                 CtdlLogPrintf(CTDL_DEBUG, "Looking up hostname '%s'\n", from_host);
 479                 if ((addr.s_addr = inet_addr(from_host)) != -1) {
 480                         locate_host(CC->cs_host, sizeof CC->cs_host,
 481                                 CC->cs_addr, sizeof CC->cs_addr,
 482                                 &addr);
 483                 }
 484                 else {
 485                         safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 486                         CC->cs_host[sizeof CC->cs_host - 1] = 0;
 487                 }
 488         }
 489
 490         CtdlLogPrintf(CTDL_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
 491                 dev_code,
 492                 cli_code,
 493                 (rev_level / 100),
 494                 (rev_level % 100),
 495                 desc,
 496                 CC->cs_host
 497         );
 498         cprintf("%d Ok\n",CIT_OK);
 499 }
 500
 501
 502 /*
 503  * display system messages or help
 504  */
 505 void cmd_mesg(char *mname)
 506 {
 507         FILE *mfp;
 508         char targ[256];
 509         char buf[256];
 510         char buf2[256];
 511         char *dirs[2];
 512         DIR *dp;
 513         struct dirent *d;
 514
 515         extract_token(buf, mname, 0, '|', sizeof buf);
 516
 517         dirs[0] = strdup(ctdl_message_dir);
 518         dirs[1] = strdup(ctdl_hlp_dir);
 519
 520         snprintf(buf2, sizeof buf2, "%s.%d.%d",
 521                 buf, CC->cs_clientdev, CC->cs_clienttyp);
 522
 523         /* If the client requested "?" then produce a listing */
 524         if (!strcmp(buf, "?")) {
 525                 cprintf("%d %s\n", LISTING_FOLLOWS, buf);
 526                 dp = opendir(dirs[1]);
 527                 if (dp != NULL) {
 528                         while (d = readdir(dp), d != NULL) {
 529                                 if (d->d_name[0] != '.') {
 530                                         cprintf(" %s\n", d->d_name);
 531                                 }
 532                         }
 533                         closedir(dp);
 534                 }
 535                 cprintf("000\n");
 536                 free(dirs[0]);
 537                 free(dirs[1]);
 538                 return;
 539         }
 540
 541         /* Otherwise, look for the requested file by name. */
 542         else {
 543                 mesg_locate(targ, sizeof targ, buf2, 2, (const char **)dirs);
 544                 if (IsEmptyStr(targ)) {
 545                         snprintf(buf2, sizeof buf2, "%s.%d",
 546                                                         buf, CC->cs_clientdev);
 547                         mesg_locate(targ, sizeof targ, buf2, 2,
 548                                                         (const char **)dirs);
 549                         if (IsEmptyStr(targ)) {
 550                                 mesg_locate(targ, sizeof targ, buf, 2,
 551                                                         (const char **)dirs);
 552                         }
 553                 }
 554         }
 555
 556         free(dirs[0]);
 557         free(dirs[1]);
 558
 559         if (IsEmptyStr(targ)) {
 560                 cprintf("%d '%s' not found.  (Searching in %s and %s)\n",
 561                         ERROR + FILE_NOT_FOUND,
 562                         mname,
 563                         ctdl_message_dir,
 564                         ctdl_hlp_dir
 565                 );
 566                 return;
 567         }
 568
 569         mfp = fopen(targ, "r");
 570         if (mfp==NULL) {
 571                 cprintf("%d Cannot open '%s': %s\n",
 572                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 573                 return;
 574         }
 575         cprintf("%d %s\n", LISTING_FOLLOWS,buf);
 576
 577         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
 578                 buf[strlen(buf)-1] = 0;
 579                 do_help_subst(buf);
 580                 cprintf("%s\n",buf);
 581         }
 582
 583         fclose(mfp);
 584         cprintf("000\n");
 585 }
 586
 587
 588 /*
 589  * enter system messages or help
 590  */
 591 void cmd_emsg(char *mname)
 592 {
 593         FILE *mfp;
 594         char targ[256];
 595         char buf[256];
 596         char *dirs[2];
 597         int a;
 598
 599         unbuffer_output();
 600
 601         if (CtdlAccessCheck(ac_aide)) return;
 602
 603         extract_token(buf, mname, 0, '|', sizeof buf);
 604         for (a=0; !IsEmptyStr(&buf[a]); ++a) {          /* security measure */
 605                 if (buf[a] == '/') buf[a] = '.';
 606         }
 607
 608         dirs[0] = strdup(ctdl_message_dir);
 609         dirs[1] = strdup(ctdl_hlp_dir);
 610
 611         mesg_locate(targ, sizeof targ, buf, 2, (const char**)dirs);
 612         free(dirs[0]);
 613         free(dirs[1]);
 614
 615         if (IsEmptyStr(targ)) {
 616                 snprintf(targ, sizeof targ,
 617                                  "%s/%s",
 618                                  ctdl_hlp_dir, buf);
 619         }
 620
 621         mfp = fopen(targ,"w");
 622         if (mfp==NULL) {
 623                 cprintf("%d Cannot open '%s': %s\n",
 624                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 625                 return;
 626         }
 627         cprintf("%d %s\n", SEND_LISTING, targ);
 628
 629         while (client_getln(buf, sizeof buf) >=0 && strcmp(buf, "000")) {
 630                 fprintf(mfp, "%s\n", buf);
 631         }
 632
 633         fclose(mfp);
 634 }
 635
 636
 637 /* Don't show the names of private rooms unless the viewing
 638  * user also knows the rooms.
 639  */
 640 void GenerateRoomDisplay(char *real_room,
 641                         CitContext *viewed,
 642                         CitContext *viewer) {
 643
 644         int ra;
 645
 646         strcpy(real_room, viewed->room.QRname);
 647         if (viewed->room.QRflags & QR_MAILBOX) {
 648                 strcpy(real_room, &real_room[11]);
 649         }
 650         if (viewed->room.QRflags & QR_PRIVATE) {
 651                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
 652                 if ( (ra & UA_KNOWN) == 0) {
 653                         strcpy(real_room, "<private room>");
 654                 }
 655         }
 656
 657         if (viewed->cs_flags & CS_CHAT) {
 658                 while (strlen(real_room) < 14) {
 659                         strcat(real_room, " ");
 660                 }
 661                 strcpy(&real_room[14], "<chat>");
 662         }
 663
 664 }
 665
 666 /*
 667  * Convenience function.
 668  */
 669 int CtdlAccessCheck(int required_level) {
 670
 671         if (CC->internal_pgm) return(0);
 672         if (required_level >= ac_internal) {
 673                 cprintf("%d This is not a user-level command.\n",
 674                         ERROR + HIGHER_ACCESS_REQUIRED);
 675                 return(-1);
 676         }
 677
 678         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
 679                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 680                 return(-1);
 681         }
 682
 683         if (CC->user.axlevel >= 6) return(0);
 684         if (required_level >= ac_aide) {
 685                 cprintf("%d This command requires Aide access.\n",
 686                         ERROR + HIGHER_ACCESS_REQUIRED);
 687                 return(-1);
 688         }
 689
 690         if (is_room_aide()) return(0);
 691         if (required_level >= ac_room_aide) {
 692                 cprintf("%d This command requires Aide or Room Aide access.\n",
 693                         ERROR + HIGHER_ACCESS_REQUIRED);
 694                 return(-1);
 695         }
 696
 697         /* shhh ... succeed quietly */
 698         return(0);
 699 }
 700
 701
 702
 703 /*
 704  * Terminate another running session
 705  */
 706 void cmd_term(char *cmdbuf)
 707 {
 708         int session_num;
 709         int terminated = 0;
 710
 711         session_num = extract_int(cmdbuf, 0);
 712
 713         terminated = CtdlTerminateOtherSession(session_num);
 714
 715         if (terminated < 0) {
 716                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
 717                 return;
 718         }
 719
 720         if (terminated & TERM_FOUND) {
 721                 if (terminated == TERM_KILLED) {
 722                         cprintf("%d Session terminated.\n", CIT_OK);
 723                 }
 724                 else {
 725                         cprintf("%d You are not allowed to do that.\n",
 726                                 ERROR + HIGHER_ACCESS_REQUIRED);
 727                 }
 728         }
 729         else {
 730                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
 731         }
 732 }
 733
 734
 735 /*
 736  * get the paginator prompt
 737  */
 738 void cmd_more(char *argbuf) {
 739         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 740 }
 741
 742
 743 /*
 744  * echo
 745  */
 746 void cmd_echo(char *etext)
 747 {
 748         cprintf("%d %s\n", CIT_OK, etext);
 749 }
 750
 751
 752 /*
 753  * Perform privilege escalation for an internal program
 754  */
 755 void cmd_ipgm(char *argbuf)
 756 {
 757         int secret;
 758
 759         secret = extract_int(argbuf, 0);
 760
 761         /* For security reasons, we do NOT allow this command to run
 762          * over the network.  Local sockets only.
 763          */
 764         if (!CC->is_local_socket) {
 765                 sleep(5);
 766                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 767         }
 768         else if (secret == config.c_ipgm_secret) {
 769                 CC->internal_pgm = 1;
 770                 strcpy(CC->curr_user, "<internal program>");
 771                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 772                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
 773         }
 774         else {
 775                 sleep(5);
 776                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 777                 CtdlLogPrintf(CTDL_ERR, "Warning: ipgm authentication failed.\n");
 778                 CC->kill_me = 1;
 779         }
 780 }
 781
 782
 783 /*
 784  * Shut down the server
 785  */
 786 void cmd_down(char *argbuf) {
 787         char *Reply ="%d Shutting down server.  Goodbye.\n";
 788
 789         if (CtdlAccessCheck(ac_aide)) return;
 790
 791         if (!IsEmptyStr(argbuf))
 792         {
 793                 int state = CIT_OK;
 794                 restart_server = extract_int(argbuf, 0);
 795
 796                 if (restart_server > 0)
 797                 {
 798                         Reply = "%d citserver will now shut down and automatically restart.\n";
 799                 }
 800                 if ((restart_server > 0) && !running_as_daemon)
 801                 {
 802                         CtdlLogPrintf(CTDL_ERR, "The user requested restart, but not running as daemon! Geronimooooooo!\n");
 803                         Reply = "%d Warning: citserver is not running in daemon mode and is therefore unlikely to restart automatically.\n";
 804                         state = ERROR;
 805                 }
 806                 cprintf(Reply, state);
 807         }
 808         else
 809         {
 810                 cprintf(Reply, CIT_OK + SERVER_SHUTTING_DOWN);
 811         }
 812         CC->kill_me = 1; /* Even the DOWN command has to follow correct proceedure when disconecting */
 813         CtdlThreadStopAll();
 814 }
 815
 816
 817 /*
 818  * Halt the server without exiting the server process.
 819  */
 820 void cmd_halt(char *argbuf) {
 821
 822         if (CtdlAccessCheck(ac_aide)) return;
 823
 824         cprintf("%d Halting server.  Goodbye.\n", CIT_OK);
 825         CtdlThreadStopAll();
 826         shutdown_and_halt = 1;
 827 }
 828
 829
 830 /*
 831  * Schedule or cancel a server shutdown
 832  */
 833 void cmd_scdn(char *argbuf)
 834 {
 835         int new_state;
 836         int state = CIT_OK;
 837         char *Reply = "%d %d\n";
 838
 839         if (CtdlAccessCheck(ac_aide)) return;
 840
 841         new_state = extract_int(argbuf, 0);
 842         if ((new_state == 2) || (new_state == 3))
 843         {
 844                 restart_server = 1;
 845                 if (!running_as_daemon)
 846                 {
 847                         CtdlLogPrintf(CTDL_ERR, "The user requested restart, but not running as deamon! Geronimooooooo!\n");
 848                         Reply = "%d %d Warning, not running in deamon mode. maybe we will come up again, but don't lean on it.\n";
 849                         state = ERROR;
 850                 }
 851
 852                 restart_server = extract_int(argbuf, 0);
 853                 new_state -= 2;
 854         }
 855         if ((new_state == 0) || (new_state == 1)) {
 856                 ScheduledShutdown = new_state;
 857         }
 858         cprintf(Reply, state, ScheduledShutdown);
 859 }
 860
 861
 862 /*
 863  * Set or unset asynchronous protocol mode
 864  */
 865 void cmd_asyn(char *argbuf)
 866 {
 867         int new_state;
 868
 869         new_state = extract_int(argbuf, 0);
 870         if ((new_state == 0) || (new_state == 1)) {
 871                 CC->is_async = new_state;
 872         }
 873         cprintf("%d %d\n", CIT_OK, CC->is_async);
 874 }
 875
 876
 877 /*
 878  * Generate a "nonce" for APOP-style authentication.
 879  *
 880  * RFC 1725 et al specify a PID to be placed in front of the nonce.
 881  * Quoth BTX: That would be stupid.
 882  */
 883 void generate_nonce(CitContext *con) {
 884         struct timeval tv;
 885
 886         memset(con->cs_nonce, NONCE_SIZE, 0);
 887         gettimeofday(&tv, NULL);
 888         memset(con->cs_nonce, NONCE_SIZE, 0);
 889         snprintf(con->cs_nonce, NONCE_SIZE, "<%d%ld@%s>",
 890                 rand(), (long)tv.tv_usec, config.c_fqdn);
 891 }
 892
 893
 894 /*
 895  * Back-end function for starting a session
 896  */
 897 void begin_session(CitContext *con)
 898 {
 899         socklen_t len;
 900         struct sockaddr_in sin;
 901
 902         /*
 903          * Initialize some variables specific to our context.
 904          */
 905         con->logged_in = 0;
 906         con->internal_pgm = 0;
 907         con->download_fp = NULL;
 908         con->upload_fp = NULL;
 909         con->FirstExpressMessage = NULL;
 910         time(&con->lastcmd);
 911         time(&con->lastidle);
 912         strcpy(con->lastcmdname, "    ");
 913         strcpy(con->cs_clientname, "(unknown)");
 914         strcpy(con->curr_user, NLI);
 915         *con->net_node = '\0';
 916         *con->fake_username = '\0';
 917         *con->fake_hostname = '\0';
 918         *con->fake_roomname = '\0';
 919         generate_nonce(con);
 920         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 921         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 922         con->cs_UDSclientUID = -1;
 923         con->cs_host[sizeof con->cs_host - 1] = 0;
 924         len = sizeof sin;
 925         if (!CC->is_local_socket) {
 926                 if (!getpeername(con->client_socket, (struct sockaddr *) &sin, &len)) {
 927                         locate_host(con->cs_host, sizeof con->cs_host,
 928                                 con->cs_addr, sizeof con->cs_addr,
 929                                 &sin.sin_addr
 930                         );
 931                 }
 932         }
 933         else {
 934                 strcpy(con->cs_host, "");
 935 #ifdef HAVE_STRUCT_UCRED
 936                 {
 937                         /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
 938                         struct ucred credentials;
 939                         socklen_t ucred_length = sizeof(struct ucred);
 940
 941                         /*fill in the user data structure */
 942                         if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
 943                                 CtdlLogPrintf(CTDL_NOTICE, "could obtain credentials from unix domain socket");
 944
 945                         }
 946                         else {
 947                                 /* the process ID of the process on the other side of the socket */
 948                                 /* credentials.pid; */
 949
 950                                 /* the effective UID of the process on the other side of the socket  */
 951                                 con->cs_UDSclientUID = credentials.uid;
 952
 953                                 /* the effective primary GID of the process on the other side of the socket */
 954                                 /* credentials.gid; */
 955
 956                                 /* To get supplemental groups, we will have to look them up in our account
 957                                    database, after a reverse lookup on the UID to get the account name.
 958                                    We can take this opportunity to check to see if this is a legit account.
 959                                 */
 960                         }
 961                 }
 962 #endif
 963         }
 964         con->cs_flags = 0;
 965         con->upload_type = UPL_FILE;
 966         con->dl_is_net = 0;
 967
 968         con->nologin = 0;
 969         if (((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions)) || CtdlWantSingleUser()) {
 970                 con->nologin = 1;
 971         }
 972
 973         if (!CC->is_local_socket) {
 974                 CtdlLogPrintf(CTDL_NOTICE, "Session started from %s [%s].\n", con->cs_host, con->cs_addr);
 975         }
 976         else {
 977                 CtdlLogPrintf(CTDL_NOTICE, "Session started via local socket.\n");
 978         }
 979
 980         /* Run any session startup routines registered by loadable modules */
 981         PerformSessionHooks(EVT_START);
 982 }
 983
 984
 985 void citproto_begin_session() {
 986         if (CC->nologin==1) {
 987                 cprintf("%d %s: Too many users are already online (maximum is %d)\n",
 988                         ERROR + MAX_SESSIONS_EXCEEDED,
 989                         config.c_nodename, config.c_maxsessions
 990                 );
 991                 CC->kill_me = 1;
 992         }
 993         else {
 994                 cprintf("%d %s Citadel server ready.\n", CIT_OK, config.c_nodename);
 995                 CC->can_receive_im = 1;
 996         }
 997 }
 998
 999
1000 void cmd_noop(char *argbuf)
1001 {
1002         cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
1003 }
1004
1005
1006 void cmd_qnop(char *argbuf)
1007 {
1008         /* do nothing, this command returns no response */
1009 }
1010
1011
1012 void cmd_quit(char *argbuf)
1013 {
1014         cprintf("%d Goodbye.\n", CIT_OK);
1015         CC->kill_me = 1;
1016 }
1017
1018
1019 void cmd_lout(char *argbuf)
1020 {
1021         if (CC->logged_in)
1022                 CtdlUserLogout();
1023         cprintf("%d logged out.\n", CIT_OK);
1024 }
1025
1026
1027 /*
1028  * This loop recognizes all server commands.
1029  */
1030 void do_command_loop(void) {
1031         char cmdbuf[SIZ];
1032         const char *old_name = NULL;
1033
1034         old_name = CtdlThreadName("do_command_loop");
1035
1036         time(&CC->lastcmd);
1037         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
1038         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
1039                 CtdlLogPrintf(CTDL_ERR, "Client disconnected: ending session.\n");
1040                 CC->kill_me = 1;
1041                 CtdlThreadName(old_name);
1042                 return;
1043         }
1044
1045         /* Log the server command, but don't show passwords... */
1046         if ( (strncasecmp(cmdbuf, "PASS", 4))
1047            && (strncasecmp(cmdbuf, "SETP", 4)) ) {
1048                 CtdlLogPrintf(CTDL_INFO, "%s\n", cmdbuf);
1049         }
1050         else {
1051                 CtdlLogPrintf(CTDL_INFO, "<password command sent>\n");
1052         }
1053
1054         buffer_output();
1055
1056         /*
1057          * Let other clients see the last command we executed, and
1058          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
1059          */
1060         if ( (strncasecmp(cmdbuf, "NOOP", 4))
1061            && (strncasecmp(cmdbuf, "QNOP", 4))
1062            && (strncasecmp(cmdbuf, "PEXP", 4))
1063            && (strncasecmp(cmdbuf, "GEXP", 4))
1064            && (strncasecmp(cmdbuf, "RWHO", 4))
1065            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
1066                 strcpy(CC->lastcmdname, "    ");
1067                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
1068                 time(&CC->lastidle);
1069         }
1070
1071         CtdlThreadName(cmdbuf);
1072
1073         if ((strncasecmp(cmdbuf, "ENT0", 4))
1074            && (strncasecmp(cmdbuf, "MESG", 4))
1075            && (strncasecmp(cmdbuf, "MSGS", 4)))
1076         {
1077            CC->cs_flags &= ~CS_POSTING;
1078         }
1079
1080         if (!DLoader_Exec_Cmd(cmdbuf)) {
1081                 cprintf("%d Unrecognized or unsupported command.\n", ERROR + CMD_NOT_SUPPORTED);
1082         }
1083
1084         unbuffer_output();
1085
1086         /* Run any after-each-command routines registered by modules */
1087         PerformSessionHooks(EVT_CMD);
1088         CtdlThreadName(old_name);
1089 }
1090
1091
1092 /*
1093  * This loop performs all asynchronous functions.
1094  */
1095 void do_async_loop(void) {
1096         PerformSessionHooks(EVT_ASYNC);
1097 }
1098
1099
1100 /*****************************************************************************/
1101 /*                      MODULE INITIALIZATION STUFF                          */
1102 /*****************************************************************************/
1103
1104 CTDL_MODULE_INIT(citserver)
1105 {
1106         if (!threading) {
1107                 CtdlRegisterProtoHook(cmd_noop, "NOOP", "no operation");
1108                 CtdlRegisterProtoHook(cmd_qnop, "QNOP", "no operation with no response");
1109                 CtdlRegisterProtoHook(cmd_quit, "QUIT", "log out and disconnect from server");
1110                 CtdlRegisterProtoHook(cmd_lout, "LOUT", "log out but do not disconnect from server");
1111                 CtdlRegisterProtoHook(cmd_asyn, "ASYN", "enable asynchronous server responses");
1112                 CtdlRegisterProtoHook(cmd_info, "INFO", "fetch server capabilities and configuration");
1113                 CtdlRegisterProtoHook(cmd_mesg, "MESG", "fetch system banners");
1114                 CtdlRegisterProtoHook(cmd_emsg, "EMSG", "submit system banners");
1115                 CtdlRegisterProtoHook(cmd_echo, "ECHO", "echo text back to the client");
1116                 CtdlRegisterProtoHook(cmd_more, "MORE", "fetch the paginator prompt");
1117                 CtdlRegisterProtoHook(cmd_iden, "IDEN", "identify the client software and location");
1118                 CtdlRegisterProtoHook(cmd_ipgm, "IPGM", "perform privilege escalation for internal programs");
1119                 CtdlRegisterProtoHook(cmd_term, "TERM", "terminate another running session");
1120                 CtdlRegisterProtoHook(cmd_down, "DOWN", "perform a server shutdown");
1121                 CtdlRegisterProtoHook(cmd_halt, "HALT", "halt the server without exiting the server process");
1122                 CtdlRegisterProtoHook(cmd_scdn, "SCDN", "schedule or cancel a server shutdown");
1123                 CtdlRegisterProtoHook(cmd_time, "TIME", "fetch the date and time from the server");
1124         }
1125         /* return our Subversion id for the Log */
1126         return "$Id$";
1127 }