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