citadel/citserver.c

   1 /*
   2  * Main source module for the Citadel server
   3  *
   4  * Copyright (c) 1987-2011 by the citadel.org team
   5  *
   6  * This program is open source software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 3.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include "sysdep.h"
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <fcntl.h>
  20 #include <signal.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23
  24 #if TIME_WITH_SYS_TIME
  25 # include <sys/time.h>
  26 # include <time.h>
  27 #else
  28 # if HAVE_SYS_TIME_H
  29 #  include <sys/time.h>
  30 # else
  31 #  include <time.h>
  32 # endif
  33 #endif
  34
  35 #if HAVE_BACKTRACE
  36 #include <execinfo.h>
  37 #endif
  38
  39 #include <ctype.h>
  40 #include <string.h>
  41 #include <dirent.h>
  42 #include <errno.h>
  43 #include <limits.h>
  44 #include <netdb.h>
  45 #include <sys/types.h>
  46 #include <sys/socket.h>
  47 #include <netinet/in.h>
  48 #include <arpa/inet.h>
  49 #include <libcitadel.h>
  50 #include "citadel.h"
  51 #include "server.h"
  52 #include "sysdep_decls.h"
  53 #include "threads.h"
  54 #include "citserver.h"
  55 #include "config.h"
  56 #include "database.h"
  57 #include "housekeeping.h"
  58 #include "user_ops.h"
  59 #include "msgbase.h"
  60 #include "support.h"
  61 #include "locate_host.h"
  62 #include "room_ops.h"
  63 #include "file_ops.h"
  64 #include "control.h"
  65 #include "euidindex.h"
  66 #include "context.h"
  67 #include "svn_revision.h"
  68
  69 #ifndef HAVE_SNPRINTF
  70 #include "snprintf.h"
  71 #endif
  72
  73 #include "ctdl_module.h"
  74
  75 char *unique_session_numbers;
  76 int ScheduledShutdown = 0;
  77 time_t server_startup_time;
  78 int panic_fd;
  79 int openid_level_supported = 0;
  80
  81 /*
  82  * print the actual stack frame.
  83  */
  84 void cit_backtrace(void)
  85 {
  86 #ifdef HAVE_BACKTRACE
  87         void *stack_frames[50];
  88         size_t size, i;
  89         char **strings;
  90
  91
  92         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
  93         strings = backtrace_symbols(stack_frames, size);
  94         for (i = 0; i < size; i++) {
  95                 if (strings != NULL)
  96                         syslog(LOG_ALERT, "%s\n", strings[i]);
  97                 else
  98                         syslog(LOG_ALERT, "%p\n", stack_frames[i]);
  99         }
 100         free(strings);
 101 #endif
 102 }
 103
 104 void cit_oneline_backtrace(void)
 105 {
 106 #ifdef HAVE_BACKTRACE
 107         void *stack_frames[50];
 108         size_t size, i;
 109         char **strings;
 110         StrBuf *Buf;
 111
 112         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 113         strings = backtrace_symbols(stack_frames, size);
 114         if (size > 0)
 115         {
 116                 Buf = NewStrBuf();
 117                 for (i = 1; i < size; i++) {
 118                         if (strings != NULL)
 119                                 StrBufAppendPrintf(Buf, "%s : ", strings[i]);
 120                         else
 121                                 StrBufAppendPrintf(Buf, "%p : ", stack_frames[i]);
 122                 }
 123                 free(strings);
 124                 syslog(LOG_ALERT, "%s\n", ChrPtr(Buf));
 125                 FreeStrBuf(&Buf);
 126         }
 127 #endif
 128 }
 129
 130 /*
 131  * print the actual stack frame.
 132  */
 133 void cit_panic_backtrace(int SigNum)
 134 {
 135 #ifdef HAVE_BACKTRACE
 136         void *stack_frames[10];
 137         size_t size, i;
 138         char **strings;
 139
 140         printf("caught signal 11\n");
 141         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 142         strings = backtrace_symbols(stack_frames, size);
 143         for (i = 0; i < size; i++) {
 144                 if (strings != NULL)
 145                         syslog(LOG_ALERT, "%s\n", strings[i]);
 146                 else
 147                         syslog(LOG_ALERT, "%p\n", stack_frames[i]);
 148         }
 149         free(strings);
 150 #endif
 151         exit(-1);
 152 }
 153
 154 /*
 155  * Various things that need to be initialized at startup
 156  */
 157 void master_startup(void) {
 158         struct timeval tv;
 159         unsigned int seed;
 160         FILE *urandom;
 161         struct ctdlroom qrbuf;
 162         int rv;
 163
 164         syslog(LOG_DEBUG, "master_startup() started\n");
 165         time(&server_startup_time);
 166         get_config();
 167
 168         syslog(LOG_INFO, "Opening databases\n");
 169         open_databases();
 170         check_ref_counts();
 171
 172         syslog(LOG_INFO, "Creating base rooms (if necessary)\n");
 173         CtdlCreateRoom(config.c_baseroom,       0, "", 0, 1, 0, VIEW_BBS);
 174         CtdlCreateRoom(AIDEROOM,                3, "", 0, 1, 0, VIEW_BBS);
 175         CtdlCreateRoom(SYSCONFIGROOM,           3, "", 0, 1, 0, VIEW_BBS);
 176         CtdlCreateRoom(config.c_twitroom,       0, "", 0, 1, 0, VIEW_BBS);
 177
 178         /* The "Local System Configuration" room doesn't need to be visible */
 179         if (CtdlGetRoomLock(&qrbuf, SYSCONFIGROOM) == 0) {
 180                 qrbuf.QRflags2 |= QR2_SYSTEM;
 181                 CtdlPutRoomLock(&qrbuf);
 182         }
 183
 184         /* Aide needs to be public postable, else we're not RFC conformant. */
 185         if (CtdlGetRoomLock(&qrbuf, AIDEROOM) == 0) {
 186                 qrbuf.QRflags2 |= QR2_SMTP_PUBLIC;
 187                 CtdlPutRoomLock(&qrbuf);
 188         }
 189
 190         syslog(LOG_INFO, "Seeding the pseudo-random number generator...\n");
 191         urandom = fopen("/dev/urandom", "r");
 192         if (urandom != NULL) {
 193                 rv = fread(&seed, sizeof seed, 1, urandom);
 194                 if (rv == -1)
 195                         syslog(LOG_EMERG, "failed to read random seed: %s\n",
 196                                strerror(errno));
 197                 fclose(urandom);
 198         }
 199         else {
 200                 gettimeofday(&tv, NULL);
 201                 seed = tv.tv_usec;
 202         }
 203         srand(seed);
 204         srandom(seed);
 205
 206         put_config();
 207
 208         syslog(LOG_DEBUG, "master_startup() finished\n");
 209 }
 210
 211
 212 /*
 213  * Cleanup routine to be called when the server is shutting down.
 214  */
 215 void master_cleanup(int exitcode) {
 216         struct CleanupFunctionHook *fcn;
 217         static int already_cleaning_up = 0;
 218
 219         if (already_cleaning_up) while(1) usleep(1000);
 220         already_cleaning_up = 1;
 221
 222         /* Run any cleanup routines registered by loadable modules */
 223         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 224                 (*fcn->h_function_pointer)();
 225         }
 226
 227         /* Close the AdjRefCount queue file */
 228         AdjRefCount(-1, 0);
 229
 230         /* Do system-dependent stuff */
 231         sysdep_master_cleanup();
 232
 233         /* Close databases */
 234         syslog(LOG_INFO, "Closing databases\n");
 235         close_databases();
 236
 237         /* If the operator requested a halt but not an exit, halt here. */
 238         if (shutdown_and_halt) {
 239                 syslog(LOG_NOTICE, "citserver: Halting server without exiting.\n");
 240                 fflush(stdout); fflush(stderr);
 241                 while(1) {
 242                         sleep(32767);
 243                 }
 244         }
 245
 246         release_control();
 247
 248         /* Now go away. */
 249         syslog(LOG_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 250         fflush(stdout); fflush(stderr);
 251
 252         if (restart_server != 0)
 253                 exit(1);
 254         if ((running_as_daemon != 0) && ((exitcode == 0) ))
 255                 exitcode = CTDLEXIT_SHUTDOWN;
 256         exit(exitcode);
 257 }
 258
 259
 260
 261 /*
 262  * cmd_info()  -  tell the client about this server
 263  */
 264 void cmd_info(char *cmdbuf) {
 265         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 266         cprintf("%d\n", CC->cs_pid);
 267         cprintf("%s\n", config.c_nodename);
 268         cprintf("%s\n", config.c_humannode);
 269         cprintf("%s\n", config.c_fqdn);
 270         cprintf("%s\n", CITADEL);
 271         cprintf("%d\n", REV_LEVEL);
 272         cprintf("%s\n", config.c_site_location);
 273         cprintf("%s\n", config.c_sysadm);
 274         cprintf("%d\n", SERVER_TYPE);
 275         cprintf("%s\n", config.c_moreprompt);
 276         cprintf("1\n"); /* 1 = yes, this system supports floors */
 277         cprintf("1\n"); /* 1 = we support the extended paging options */
 278         cprintf("\n");  /* nonce no longer supported */
 279         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 280
 281 #ifdef HAVE_LDAP
 282         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
 283 #else
 284         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
 285 #endif
 286
 287         if ((config.c_auth_mode == AUTHMODE_NATIVE) &&
 288             (config.c_disable_newu == 0))
 289         {
 290                 cprintf("%d\n", config.c_disable_newu);
 291         }
 292         else {
 293                 cprintf("1\n"); /* "create new user" does not work with non-native auth modes */
 294         }
 295
 296         cprintf("%s\n", config.c_default_cal_zone);
 297
 298         /* thread load averages -- temporarily disabled during refactoring of this code */
 299         cprintf("0\n");         /* load average */
 300         cprintf("0\n");         /* worker average */
 301         cprintf("0\n");         /* thread count */
 302
 303         cprintf("1\n");         /* yes, Sieve mail filtering is supported */
 304         cprintf("%d\n", config.c_enable_fulltext);
 305         cprintf("%s\n", svn_revision());
 306
 307         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 308                 cprintf("%d\n", openid_level_supported); /* OpenID is enabled when using native auth */
 309         }
 310         else {
 311                 cprintf("0\n"); /* OpenID is disabled when using non-native auth */
 312         }
 313
 314         cprintf("%d\n", config.c_guest_logins);
 315
 316         cprintf("000\n");
 317 }
 318
 319
 320 /*
 321  * returns an asterisk if there are any instant messages waiting,
 322  * space otherwise.
 323  */
 324 char CtdlCheckExpress(void) {
 325         if (CC->FirstExpressMessage == NULL) {
 326                 return(' ');
 327         }
 328         else {
 329                 return('*');
 330         }
 331 }
 332
 333 void cmd_time(char *argbuf)
 334 {
 335    time_t tv;
 336    struct tm tmp;
 337
 338    tv = time(NULL);
 339    localtime_r(&tv, &tmp);
 340
 341    /* timezone and daylight global variables are not portable. */
 342 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 343    cprintf("%d %ld|%ld|%d|%ld\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst, server_startup_time);
 344 #else
 345    cprintf("%d %ld|%ld|%d|%ld\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst, server_startup_time);
 346 #endif
 347 }
 348
 349
 350 /*
 351  * Check originating host against the public_clients file.  This determines
 352  * whether the client is allowed to change the hostname for this session
 353  * (for example, to show the location of the user rather than the location
 354  * of the client).
 355  */
 356 int is_public_client(void)
 357 {
 358         char buf[1024];
 359         char addrbuf[1024];
 360         FILE *fp;
 361         int i;
 362         char *public_clientspos;
 363         char *public_clientsend;
 364         char *paddr = NULL;
 365         struct stat statbuf;
 366         static time_t pc_timestamp = 0;
 367         static char public_clients[SIZ];
 368         static char public_clients_file[SIZ];
 369
 370 #define LOCALHOSTSTR "127.0.0.1"
 371
 372         snprintf(public_clients_file, sizeof public_clients_file, "%s/public_clients", ctdl_etc_dir);
 373
 374         /*
 375          * Check the time stamp on the public_clients file.  If it's been
 376          * updated since the last time we were here (or if this is the first
 377          * time we've been through the loop), read its contents and learn
 378          * the IP addresses of the listed hosts.
 379          */
 380         if (stat(public_clients_file, &statbuf) != 0) {
 381                 /* No public_clients file exists, so bail out */
 382                 syslog(LOG_WARNING, "Warning: '%s' does not exist\n",
 383                                 public_clients_file);
 384                 return(0);
 385         }
 386
 387         if (statbuf.st_mtime > pc_timestamp) {
 388                 begin_critical_section(S_PUBLIC_CLIENTS);
 389                 syslog(LOG_INFO, "Loading %s\n", public_clients_file);
 390
 391                 public_clientspos = &public_clients[0];
 392                 public_clientsend = public_clientspos + SIZ;
 393                 safestrncpy(public_clientspos, LOCALHOSTSTR, sizeof public_clients);
 394                 public_clientspos += sizeof(LOCALHOSTSTR) - 1;
 395
 396                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 397                         *(public_clientspos++) = '|';
 398                         paddr = &addrbuf[0];
 399                         while (!IsEmptyStr (paddr) &&
 400                                (public_clientspos < public_clientsend))
 401                                 *(public_clientspos++) = *(paddr++);
 402                 }
 403
 404                 fp = fopen(public_clients_file, "r");
 405                 if (fp != NULL)
 406                         while ((fgets(buf, sizeof buf, fp)!=NULL) &&
 407                                (public_clientspos < public_clientsend)){
 408                                 char *ptr;
 409                                 ptr = buf;
 410                                 while (!IsEmptyStr(ptr)) {
 411                                         if (*ptr == '#') {
 412                                                 *ptr = 0;
 413                                                 break;
 414                                         }
 415                                 else ptr++;
 416                                 }
 417                                 ptr--;
 418                                 while (ptr>buf && isspace(*ptr)) {
 419                                         *(ptr--) = 0;
 420                                 }
 421                                 if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 422                                         *(public_clientspos++) = '|';
 423                                         paddr = addrbuf;
 424                                         while (!IsEmptyStr(paddr) &&
 425                                                (public_clientspos < public_clientsend)){
 426                                                 *(public_clientspos++) = *(paddr++);
 427                                         }
 428                                 }
 429                         }
 430                 fclose(fp);
 431                 pc_timestamp = time(NULL);
 432                 end_critical_section(S_PUBLIC_CLIENTS);
 433         }
 434
 435         syslog(LOG_DEBUG, "Checking whether %s is a local or public client\n",
 436                 CC->cs_addr);
 437         for (i=0; i<num_parms(public_clients); ++i) {
 438                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 439                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 440                         syslog(LOG_DEBUG, "... yes its local.\n");
 441                         return(1);
 442                 }
 443         }
 444
 445         /* No hits.  This is not a public client. */
 446         syslog(LOG_DEBUG, "... no it isn't.\n");
 447         return(0);
 448 }
 449
 450
 451 /*
 452  * the client is identifying itself to the server
 453  */
 454 void cmd_iden(char *argbuf)
 455 {
 456         int dev_code;
 457         int cli_code;
 458         int rev_level;
 459         char desc[128];
 460         char from_host[128];
 461
 462         if (num_parms(argbuf)<4) {
 463                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
 464                 return;
 465         }
 466
 467         dev_code = extract_int(argbuf,0);
 468         cli_code = extract_int(argbuf,1);
 469         rev_level = extract_int(argbuf,2);
 470         extract_token(desc, argbuf, 3, '|', sizeof desc);
 471
 472         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 473         from_host[sizeof from_host - 1] = 0;
 474         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
 475
 476         CC->cs_clientdev = dev_code;
 477         CC->cs_clienttyp = cli_code;
 478         CC->cs_clientver = rev_level;
 479         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 480         CC->cs_clientname[31] = 0;
 481
 482         /* For local sockets and public clients, trust the hostname supplied by the client */
 483         if ( (CC->is_local_socket) || (is_public_client()) ) {
 484                 safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 485                 CC->cs_host[sizeof CC->cs_host - 1] = 0;
 486                 CC->cs_addr[0] = 0;
 487         }
 488
 489         syslog(LOG_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
 490                 dev_code,
 491                 cli_code,
 492                 (rev_level / 100),
 493                 (rev_level % 100),
 494                 desc,
 495                 CC->cs_host
 496         );
 497         cprintf("%d Ok\n",CIT_OK);
 498 }
 499
 500 typedef const char *ccharp;
 501 /*
 502  * display system messages or help
 503  */
 504 void cmd_mesg(char *mname)
 505 {
 506         FILE *mfp;
 507         char targ[256];
 508         char buf[256];
 509         char buf2[256];
 510         char *dirs[2];
 511         DIR *dp;
 512         struct dirent *d;
 513
 514         extract_token(buf, mname, 0, '|', sizeof buf);
 515
 516         dirs[0] = strdup(ctdl_message_dir);
 517         dirs[1] = strdup(ctdl_hlp_dir);
 518
 519         snprintf(buf2, sizeof buf2, "%s.%d.%d",
 520                 buf, CC->cs_clientdev, CC->cs_clienttyp);
 521
 522         /* If the client requested "?" then produce a listing */
 523         if (!strcmp(buf, "?")) {
 524                 cprintf("%d %s\n", LISTING_FOLLOWS, buf);
 525                 dp = opendir(dirs[1]);
 526                 if (dp != NULL) {
 527                         while (d = readdir(dp), d != NULL) {
 528                                 if (d->d_name[0] != '.') {
 529                                         cprintf(" %s\n", d->d_name);
 530                                 }
 531                         }
 532                         closedir(dp);
 533                 }
 534                 cprintf("000\n");
 535                 free(dirs[0]);
 536                 free(dirs[1]);
 537                 return;
 538         }
 539
 540         /* Otherwise, look for the requested file by name. */
 541         else {
 542                 mesg_locate(targ, sizeof targ, buf2, 2, (const ccharp*)dirs);
 543                 if (IsEmptyStr(targ)) {
 544                         snprintf(buf2, sizeof buf2, "%s.%d",
 545                                                         buf, CC->cs_clientdev);
 546                         mesg_locate(targ, sizeof targ, buf2, 2,
 547                                     (const ccharp*)dirs);
 548                         if (IsEmptyStr(targ)) {
 549                                 mesg_locate(targ, sizeof targ, buf, 2,
 550                                             (const ccharp*)dirs);
 551                         }
 552                 }
 553         }
 554
 555         free(dirs[0]);
 556         free(dirs[1]);
 557
 558         if (IsEmptyStr(targ)) {
 559                 cprintf("%d '%s' not found.  (Searching in %s and %s)\n",
 560                         ERROR + FILE_NOT_FOUND,
 561                         mname,
 562                         ctdl_message_dir,
 563                         ctdl_hlp_dir
 564                 );
 565                 return;
 566         }
 567
 568         mfp = fopen(targ, "r");
 569         if (mfp==NULL) {
 570                 cprintf("%d Cannot open '%s': %s\n",
 571                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 572                 return;
 573         }
 574         cprintf("%d %s\n", LISTING_FOLLOWS,buf);
 575
 576         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
 577                 buf[strlen(buf)-1] = 0;
 578                 do_help_subst(buf);
 579                 cprintf("%s\n",buf);
 580         }
 581
 582         fclose(mfp);
 583         cprintf("000\n");
 584 }
 585
 586
 587 /*
 588  * enter system messages or help
 589  */
 590 void cmd_emsg(char *mname)
 591 {
 592         FILE *mfp;
 593         char targ[256];
 594         char buf[256];
 595         char *dirs[2];
 596         int a;
 597
 598         unbuffer_output();
 599
 600         if (CtdlAccessCheck(ac_aide)) return;
 601
 602         extract_token(buf, mname, 0, '|', sizeof buf);
 603         for (a=0; !IsEmptyStr(&buf[a]); ++a) {          /* security measure */
 604                 if (buf[a] == '/') buf[a] = '.';
 605         }
 606
 607         dirs[0] = strdup(ctdl_message_dir);
 608         dirs[1] = strdup(ctdl_hlp_dir);
 609
 610         mesg_locate(targ, sizeof targ, buf, 2, (const ccharp*)dirs);
 611         free(dirs[0]);
 612         free(dirs[1]);
 613
 614         if (IsEmptyStr(targ)) {
 615                 snprintf(targ, sizeof targ,
 616                                  "%s/%s",
 617                                  ctdl_hlp_dir, buf);
 618         }
 619
 620         mfp = fopen(targ,"w");
 621         if (mfp==NULL) {
 622                 cprintf("%d Cannot open '%s': %s\n",
 623                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 624                 return;
 625         }
 626         cprintf("%d %s\n", SEND_LISTING, targ);
 627
 628         while (client_getln(buf, sizeof buf) >=0 && strcmp(buf, "000")) {
 629                 fprintf(mfp, "%s\n", buf);
 630         }
 631
 632         fclose(mfp);
 633 }
 634
 635
 636 /* Don't show the names of private rooms unless the viewing
 637  * user also knows the rooms.
 638  */
 639 void GenerateRoomDisplay(char *real_room,
 640                         CitContext *viewed,
 641                         CitContext *viewer) {
 642
 643         int ra;
 644
 645         strcpy(real_room, viewed->room.QRname);
 646         if (viewed->room.QRflags & QR_MAILBOX) {
 647                 strcpy(real_room, &real_room[11]);
 648         }
 649         if (viewed->room.QRflags & QR_PRIVATE) {
 650                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
 651                 if ( (ra & UA_KNOWN) == 0) {
 652                         strcpy(real_room, " ");
 653                 }
 654         }
 655
 656         if (viewed->cs_flags & CS_CHAT) {
 657                 while (strlen(real_room) < 14) {
 658                         strcat(real_room, " ");
 659                 }
 660                 strcpy(&real_room[14], "<chat>");
 661         }
 662
 663 }
 664
 665 /*
 666  * Convenience function.
 667  */
 668 int CtdlAccessCheck(int required_level) {
 669
 670         if (CC->internal_pgm) return(0);
 671         if (required_level >= ac_internal) {
 672                 cprintf("%d This is not a user-level command.\n",
 673                         ERROR + HIGHER_ACCESS_REQUIRED);
 674                 return(-1);
 675         }
 676
 677         if ((required_level >= ac_logged_in_or_guest) && (CC->logged_in == 0) && (!config.c_guest_logins)) {
 678                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 679                 return(-1);
 680         }
 681
 682         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
 683                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 684                 return(-1);
 685         }
 686
 687         if (CC->user.axlevel >= AxAideU) return(0);
 688         if (required_level >= ac_aide) {
 689                 cprintf("%d This command requires Aide access.\n",
 690                         ERROR + HIGHER_ACCESS_REQUIRED);
 691                 return(-1);
 692         }
 693
 694         if (is_room_aide()) return(0);
 695         if (required_level >= ac_room_aide) {
 696                 cprintf("%d This command requires Aide or Room Aide access.\n",
 697                         ERROR + HIGHER_ACCESS_REQUIRED);
 698                 return(-1);
 699         }
 700
 701         /* shhh ... succeed quietly */
 702         return(0);
 703 }
 704
 705
 706
 707 /*
 708  * Terminate another running session
 709  */
 710 void cmd_term(char *cmdbuf)
 711 {
 712         int session_num;
 713         int terminated = 0;
 714
 715         session_num = extract_int(cmdbuf, 0);
 716
 717         terminated = CtdlTerminateOtherSession(session_num);
 718
 719         if (terminated < 0) {
 720                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
 721                 return;
 722         }
 723
 724         if (terminated & TERM_FOUND) {
 725                 if (terminated == TERM_KILLED) {
 726                         cprintf("%d Session terminated.\n", CIT_OK);
 727                 }
 728                 else {
 729                         cprintf("%d You are not allowed to do that.\n",
 730                                 ERROR + HIGHER_ACCESS_REQUIRED);
 731                 }
 732         }
 733         else {
 734                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
 735         }
 736 }
 737
 738
 739 /*
 740  * get the paginator prompt
 741  */
 742 void cmd_more(char *argbuf) {
 743         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 744 }
 745
 746
 747 /*
 748  * echo
 749  */
 750 void cmd_echo(char *etext)
 751 {
 752         cprintf("%d %s\n", CIT_OK, etext);
 753 }
 754
 755
 756
 757 /*
 758  * Shut down the server
 759  */
 760 void cmd_down(char *argbuf) {
 761         char *Reply ="%d Shutting down server.  Goodbye.\n";
 762
 763         if (CtdlAccessCheck(ac_aide)) return;
 764
 765         if (!IsEmptyStr(argbuf))
 766         {
 767                 int state = CIT_OK;
 768                 restart_server = extract_int(argbuf, 0);
 769
 770                 if (restart_server > 0)
 771                 {
 772                         Reply = "%d citserver will now shut down and automatically restart.\n";
 773                 }
 774                 if ((restart_server > 0) && !running_as_daemon)
 775                 {
 776                         syslog(LOG_ERR, "The user requested restart, but not running as daemon! Geronimooooooo!\n");
 777                         Reply = "%d Warning: citserver is not running in daemon mode and is therefore unlikely to restart automatically.\n";
 778                         state = ERROR;
 779                 }
 780                 cprintf(Reply, state);
 781         }
 782         else
 783         {
 784                 cprintf(Reply, CIT_OK + SERVER_SHUTTING_DOWN);
 785         }
 786         CC->kill_me = KILLME_SERVER_SHUTTING_DOWN;
 787         server_shutting_down = 1;
 788 }
 789
 790
 791 /*
 792  * Halt the server without exiting the server process.
 793  */
 794 void cmd_halt(char *argbuf) {
 795
 796         if (CtdlAccessCheck(ac_aide)) return;
 797
 798         cprintf("%d Halting server.  Goodbye.\n", CIT_OK);
 799         server_shutting_down = 1;
 800         shutdown_and_halt = 1;
 801 }
 802
 803
 804 /*
 805  * Schedule or cancel a server shutdown
 806  */
 807 void cmd_scdn(char *argbuf)
 808 {
 809         int new_state;
 810         int state = CIT_OK;
 811         char *Reply = "%d %d\n";
 812
 813         if (CtdlAccessCheck(ac_aide)) return;
 814
 815         new_state = extract_int(argbuf, 0);
 816         if ((new_state == 2) || (new_state == 3))
 817         {
 818                 restart_server = 1;
 819                 if (!running_as_daemon)
 820                 {
 821                         syslog(LOG_ERR, "The user requested restart, but not running as deamon! Geronimooooooo!\n");
 822                         Reply = "%d %d Warning, not running in deamon mode. maybe we will come up again, but don't lean on it.\n";
 823                         state = ERROR;
 824                 }
 825
 826                 restart_server = extract_int(argbuf, 0);
 827                 new_state -= 2;
 828         }
 829         if ((new_state == 0) || (new_state == 1)) {
 830                 ScheduledShutdown = new_state;
 831         }
 832         cprintf(Reply, state, ScheduledShutdown);
 833 }
 834
 835
 836 /*
 837  * Set or unset asynchronous protocol mode
 838  */
 839 void cmd_asyn(char *argbuf)
 840 {
 841         int new_state;
 842
 843         new_state = extract_int(argbuf, 0);
 844         if ((new_state == 0) || (new_state == 1)) {
 845                 CC->is_async = new_state;
 846         }
 847         cprintf("%d %d\n", CIT_OK, CC->is_async);
 848 }
 849
 850
 851
 852 /*
 853  * Back-end function for starting a session
 854  */
 855 void begin_session(CitContext *con)
 856 {
 857         /*
 858          * Initialize some variables specific to our context.
 859          */
 860         con->logged_in = 0;
 861         con->internal_pgm = 0;
 862         con->download_fp = NULL;
 863         con->upload_fp = NULL;
 864         con->cached_msglist = NULL;
 865         con->cached_num_msgs = 0;
 866         con->FirstExpressMessage = NULL;
 867         time(&con->lastcmd);
 868         time(&con->lastidle);
 869         strcpy(con->lastcmdname, "    ");
 870         strcpy(con->cs_clientname, "(unknown)");
 871         strcpy(con->curr_user, NLI);
 872         *con->net_node = '\0';
 873         *con->fake_username = '\0';
 874         *con->fake_hostname = '\0';
 875         *con->fake_roomname = '\0';
 876         *con->cs_clientinfo = '\0';
 877         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 878         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 879         con->cs_UDSclientUID = -1;
 880         con->cs_host[sizeof con->cs_host - 1] = 0;
 881         if (!CC->is_local_socket) {
 882                 locate_host(con->cs_host, sizeof con->cs_host,
 883                         con->cs_addr, sizeof con->cs_addr,
 884                         con->client_socket
 885                 );
 886         }
 887         else {
 888                 con->cs_host[0] = 0;
 889                 con->cs_addr[0] = 0;
 890 #ifdef HAVE_STRUCT_UCRED
 891                 {
 892                         /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
 893                         struct ucred credentials;
 894                         socklen_t ucred_length = sizeof(struct ucred);
 895
 896                         /*fill in the user data structure */
 897                         if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
 898                                 syslog(LOG_NOTICE, "could obtain credentials from unix domain socket");
 899
 900                         }
 901                         else {
 902                                 /* the process ID of the process on the other side of the socket */
 903                                 /* credentials.pid; */
 904
 905                                 /* the effective UID of the process on the other side of the socket  */
 906                                 con->cs_UDSclientUID = credentials.uid;
 907
 908                                 /* the effective primary GID of the process on the other side of the socket */
 909                                 /* credentials.gid; */
 910
 911                                 /* To get supplemental groups, we will have to look them up in our account
 912                                    database, after a reverse lookup on the UID to get the account name.
 913                                    We can take this opportunity to check to see if this is a legit account.
 914                                 */
 915                                 snprintf(con->cs_clientinfo, sizeof(con->cs_clientinfo),
 916                                          "PID: "F_PID_T"; UID: "F_UID_T"; GID: "F_XPID_T" ",
 917                                          credentials.pid,
 918                                          credentials.uid,
 919                                          credentials.gid);
 920                         }
 921                 }
 922 #endif
 923         }
 924         con->cs_flags = 0;
 925         con->upload_type = UPL_FILE;
 926         con->dl_is_net = 0;
 927
 928         con->nologin = 0;
 929         if (((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions)) || CtdlWantSingleUser()) {
 930                 con->nologin = 1;
 931         }
 932
 933         if (!CC->is_local_socket) {
 934                 syslog(LOG_NOTICE, "Session (%s) started from %s (%s).\n", con->ServiceName, con->cs_host, con->cs_addr);
 935         }
 936         else {
 937                 syslog(LOG_NOTICE, "Session (%s) started via local socket UID:%d.\n", con->ServiceName, con->cs_UDSclientUID);
 938         }
 939
 940         /* Run any session startup routines registered by loadable modules */
 941         PerformSessionHooks(EVT_START);
 942 }
 943
 944
 945 void citproto_begin_session() {
 946         if (CC->nologin==1) {
 947                 cprintf("%d %s: Too many users are already online (maximum is %d)\n",
 948                         ERROR + MAX_SESSIONS_EXCEEDED,
 949                         config.c_nodename, config.c_maxsessions
 950                 );
 951                 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
 952         }
 953         else {
 954                 cprintf("%d %s Citadel server ready.\n", CIT_OK, config.c_nodename);
 955                 CC->can_receive_im = 1;
 956         }
 957 }
 958
 959
 960 void citproto_begin_admin_session() {
 961         CC->internal_pgm = 1;
 962         cprintf("%d %s Citadel server ADMIN CONNECTION ready.\n", CIT_OK, config.c_nodename);
 963 }
 964
 965
 966 void cmd_noop(char *argbuf)
 967 {
 968         cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
 969 }
 970
 971
 972 void cmd_qnop(char *argbuf)
 973 {
 974         /* do nothing, this command returns no response */
 975 }
 976
 977
 978 void cmd_quit(char *argbuf)
 979 {
 980         cprintf("%d Goodbye.\n", CIT_OK);
 981         CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
 982 }
 983
 984
 985 void cmd_lout(char *argbuf)
 986 {
 987         if (CC->logged_in)
 988                 CtdlUserLogout();
 989         cprintf("%d logged out.\n", CIT_OK);
 990 }
 991
 992
 993 /*
 994  * This loop recognizes all server commands.
 995  */
 996 void do_command_loop(void) {
 997         char cmdbuf[SIZ];
 998
 999         time(&CC->lastcmd);
1000         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
1001         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
1002                 syslog(LOG_ERR, "Citadel client disconnected: ending session.\n");
1003                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1004                 return;
1005         }
1006
1007         /* Log the server command, but don't show passwords... */
1008         if ( (strncasecmp(cmdbuf, "PASS", 4)) && (strncasecmp(cmdbuf, "SETP", 4)) ) {
1009                 syslog(LOG_INFO, "[%d][%s(%ld)] %s",
1010                         CC->cs_pid, CC->curr_user, CC->user.usernum, cmdbuf
1011                 );
1012         }
1013         else {
1014                 syslog(LOG_INFO, "[%d][%s(%ld)] <password command hidden from log>",
1015                         CC->cs_pid, CC->curr_user, CC->user.usernum
1016                 );
1017         }
1018
1019         buffer_output();
1020
1021         /*
1022          * Let other clients see the last command we executed, and
1023          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
1024          */
1025         if ( (strncasecmp(cmdbuf, "NOOP", 4))
1026            && (strncasecmp(cmdbuf, "QNOP", 4))
1027            && (strncasecmp(cmdbuf, "PEXP", 4))
1028            && (strncasecmp(cmdbuf, "GEXP", 4))
1029            && (strncasecmp(cmdbuf, "RWHO", 4))
1030            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
1031                 strcpy(CC->lastcmdname, "    ");
1032                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
1033                 time(&CC->lastidle);
1034         }
1035
1036         if ((strncasecmp(cmdbuf, "ENT0", 4))
1037            && (strncasecmp(cmdbuf, "MESG", 4))
1038            && (strncasecmp(cmdbuf, "MSGS", 4)))
1039         {
1040            CC->cs_flags &= ~CS_POSTING;
1041         }
1042
1043         if (!DLoader_Exec_Cmd(cmdbuf)) {
1044                 cprintf("%d Unrecognized or unsupported command.\n", ERROR + CMD_NOT_SUPPORTED);
1045         }
1046
1047         unbuffer_output();
1048
1049         /* Run any after-each-command routines registered by modules */
1050         PerformSessionHooks(EVT_CMD);
1051 }
1052
1053
1054 /*
1055  * This loop performs all asynchronous functions.
1056  */
1057 void do_async_loop(void) {
1058         PerformSessionHooks(EVT_ASYNC);
1059 }
1060
1061
1062 /*****************************************************************************/
1063 /*                      MODULE INITIALIZATION STUFF                          */
1064 /*****************************************************************************/
1065
1066 CTDL_MODULE_INIT(citserver)
1067 {
1068         if (!threading) {
1069                 CtdlRegisterProtoHook(cmd_noop, "NOOP", "no operation");
1070                 CtdlRegisterProtoHook(cmd_qnop, "QNOP", "no operation with no response");
1071                 CtdlRegisterProtoHook(cmd_quit, "QUIT", "log out and disconnect from server");
1072                 CtdlRegisterProtoHook(cmd_lout, "LOUT", "log out but do not disconnect from server");
1073                 CtdlRegisterProtoHook(cmd_asyn, "ASYN", "enable asynchronous server responses");
1074                 CtdlRegisterProtoHook(cmd_info, "INFO", "fetch server capabilities and configuration");
1075                 CtdlRegisterProtoHook(cmd_mesg, "MESG", "fetch system banners");
1076                 CtdlRegisterProtoHook(cmd_emsg, "EMSG", "submit system banners");
1077                 CtdlRegisterProtoHook(cmd_echo, "ECHO", "echo text back to the client");
1078                 CtdlRegisterProtoHook(cmd_more, "MORE", "fetch the paginator prompt");
1079                 CtdlRegisterProtoHook(cmd_iden, "IDEN", "identify the client software and location");
1080                 CtdlRegisterProtoHook(cmd_term, "TERM", "terminate another running session");
1081                 CtdlRegisterProtoHook(cmd_down, "DOWN", "perform a server shutdown");
1082                 CtdlRegisterProtoHook(cmd_halt, "HALT", "halt the server without exiting the server process");
1083                 CtdlRegisterProtoHook(cmd_scdn, "SCDN", "schedule or cancel a server shutdown");
1084                 CtdlRegisterProtoHook(cmd_time, "TIME", "fetch the date and time from the server");
1085         }
1086         /* return our id for the Log */
1087         return "citserver";
1088 }