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