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                 if (rv == -1)
 200                         syslog(LOG_EMERG, "failed to read random seed: %s\n",
 201                                strerror(errno));
 202                 fclose(urandom);
 203         }
 204         else {
 205                 gettimeofday(&tv, NULL);
 206                 seed = tv.tv_usec;
 207         }
 208         srand(seed);
 209         srandom(seed);
 210
 211         syslog(LOG_INFO, "Initializing ipgm secret\n");
 212         get_config();
 213         config.c_ipgm_secret = rand();
 214         put_config();
 215
 216         syslog(LOG_DEBUG, "master_startup() finished\n");
 217 }
 218
 219
 220 /*
 221  * Cleanup routine to be called when the server is shutting down.
 222  */
 223 void master_cleanup(int exitcode) {
 224         struct CleanupFunctionHook *fcn;
 225         static int already_cleaning_up = 0;
 226
 227         if (already_cleaning_up) while(1) sleep(1);
 228         already_cleaning_up = 1;
 229
 230         /* Run any cleanup routines registered by loadable modules */
 231         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 232                 (*fcn->h_function_pointer)();
 233         }
 234
 235         /* Close the AdjRefCount queue file */
 236         AdjRefCount(-1, 0);
 237
 238         /* Do system-dependent stuff */
 239         sysdep_master_cleanup();
 240
 241         /* Close databases */
 242         syslog(LOG_INFO, "Closing databases\n");
 243         close_databases();
 244
 245         /* If the operator requested a halt but not an exit, halt here. */
 246         if (shutdown_and_halt) {
 247                 syslog(LOG_NOTICE, "citserver: Halting server without exiting.\n");
 248                 fflush(stdout); fflush(stderr);
 249                 while(1) {
 250                         sleep(32767);
 251                 }
 252         }
 253
 254         release_control();
 255
 256         /* Now go away. */
 257         syslog(LOG_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 258         fflush(stdout); fflush(stderr);
 259
 260         if (restart_server != 0)
 261                 exit(1);
 262         if ((running_as_daemon != 0) && ((exitcode == 0) ))
 263                 exitcode = CTDLEXIT_SHUTDOWN;
 264         exit(exitcode);
 265 }
 266
 267
 268
 269 /*
 270  * cmd_info()  -  tell the client about this server
 271  */
 272 void cmd_info(char *cmdbuf) {
 273         cprintf("%d Server info:\n", LISTING_FOLLOWS);
 274         cprintf("%d\n", CC->cs_pid);
 275         cprintf("%s\n", config.c_nodename);
 276         cprintf("%s\n", config.c_humannode);
 277         cprintf("%s\n", config.c_fqdn);
 278         cprintf("%s\n", CITADEL);
 279         cprintf("%d\n", REV_LEVEL);
 280         cprintf("%s\n", config.c_site_location);
 281         cprintf("%s\n", config.c_sysadm);
 282         cprintf("%d\n", SERVER_TYPE);
 283         cprintf("%s\n", config.c_moreprompt);
 284         cprintf("1\n"); /* 1 = yes, this system supports floors */
 285         cprintf("1\n"); /* 1 = we support the extended paging options */
 286         cprintf("\n");  /* nonce no longer supported */
 287         cprintf("1\n"); /* 1 = yes, this system supports the QNOP command */
 288
 289 #ifdef HAVE_LDAP
 290         cprintf("1\n"); /* 1 = yes, this server is LDAP-enabled */
 291 #else
 292         cprintf("0\n"); /* 1 = no, this server is not LDAP-enabled */
 293 #endif
 294
 295         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 296                 cprintf("%d\n", config.c_disable_newu);
 297         }
 298         else {
 299                 cprintf("1\n"); /* "create new user" does not work with non-native auth modes */
 300         }
 301
 302         cprintf("%s\n", config.c_default_cal_zone);
 303
 304         /* thread load averages -- temporarily disabled during refactoring of this code */
 305         cprintf("0\n");         /* load average */
 306         cprintf("0\n");         /* worker average */
 307         cprintf("0\n");         /* thread count */
 308
 309         cprintf("1\n");         /* yes, Sieve mail filtering is supported */
 310         cprintf("%d\n", config.c_enable_fulltext);
 311         cprintf("%s\n", svn_revision());
 312
 313         if (config.c_auth_mode == AUTHMODE_NATIVE) {
 314                 cprintf("%d\n", openid_level_supported); /* OpenID is enabled when using native auth */
 315         }
 316         else {
 317                 cprintf("0\n"); /* OpenID is disabled when using non-native auth */
 318         }
 319
 320         cprintf("%d\n", config.c_guest_logins);
 321
 322         cprintf("000\n");
 323 }
 324
 325
 326 /*
 327  * returns an asterisk if there are any instant messages waiting,
 328  * space otherwise.
 329  */
 330 char CtdlCheckExpress(void) {
 331         if (CC->FirstExpressMessage == NULL) {
 332                 return(' ');
 333         }
 334         else {
 335                 return('*');
 336         }
 337 }
 338
 339 void cmd_time(char *argbuf)
 340 {
 341    time_t tv;
 342    struct tm tmp;
 343
 344    tv = time(NULL);
 345    localtime_r(&tv, &tmp);
 346
 347    /* timezone and daylight global variables are not portable. */
 348 #ifdef HAVE_STRUCT_TM_TM_GMTOFF
 349    cprintf("%d %ld|%ld|%d|%ld\n", CIT_OK, (long)tv, tmp.tm_gmtoff, tmp.tm_isdst, server_startup_time);
 350 #else
 351    cprintf("%d %ld|%ld|%d|%ld\n", CIT_OK, (long)tv, timezone, tmp.tm_isdst, server_startup_time);
 352 #endif
 353 }
 354
 355
 356 /*
 357  * Check originating host against the public_clients file.  This determines
 358  * whether the client is allowed to change the hostname for this session
 359  * (for example, to show the location of the user rather than the location
 360  * of the client).
 361  */
 362 int is_public_client(void)
 363 {
 364         char buf[1024];
 365         char addrbuf[1024];
 366         FILE *fp;
 367         int i;
 368         char *public_clientspos;
 369         char *public_clientsend;
 370         char *paddr = NULL;
 371         struct stat statbuf;
 372         static time_t pc_timestamp = 0;
 373         static char public_clients[SIZ];
 374         static char public_clients_file[SIZ];
 375
 376 #define LOCALHOSTSTR "127.0.0.1"
 377
 378         snprintf(public_clients_file, sizeof public_clients_file, "%s/public_clients", ctdl_etc_dir);
 379
 380         /*
 381          * Check the time stamp on the public_clients file.  If it's been
 382          * updated since the last time we were here (or if this is the first
 383          * time we've been through the loop), read its contents and learn
 384          * the IP addresses of the listed hosts.
 385          */
 386         if (stat(public_clients_file, &statbuf) != 0) {
 387                 /* No public_clients file exists, so bail out */
 388                 syslog(LOG_WARNING, "Warning: '%s' does not exist\n",
 389                                 public_clients_file);
 390                 return(0);
 391         }
 392
 393         if (statbuf.st_mtime > pc_timestamp) {
 394                 begin_critical_section(S_PUBLIC_CLIENTS);
 395                 syslog(LOG_INFO, "Loading %s\n", public_clients_file);
 396
 397                 public_clientspos = &public_clients[0];
 398                 public_clientsend = public_clientspos + SIZ;
 399                 safestrncpy(public_clientspos, LOCALHOSTSTR, sizeof public_clients);
 400                 public_clientspos += sizeof(LOCALHOSTSTR) - 1;
 401
 402                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 403                         *(public_clientspos++) = '|';
 404                         paddr = &addrbuf[0];
 405                         while (!IsEmptyStr (paddr) &&
 406                                (public_clientspos < public_clientsend))
 407                                 *(public_clientspos++) = *(paddr++);
 408                 }
 409
 410                 fp = fopen(public_clients_file, "r");
 411                 if (fp != NULL)
 412                         while ((fgets(buf, sizeof buf, fp)!=NULL) &&
 413                                (public_clientspos < public_clientsend)){
 414                                 char *ptr;
 415                                 ptr = buf;
 416                                 while (!IsEmptyStr(ptr)) {
 417                                         if (*ptr == '#') {
 418                                                 *ptr = 0;
 419                                                 break;
 420                                         }
 421                                 else ptr++;
 422                                 }
 423                                 ptr--;
 424                                 while (ptr>buf && isspace(*ptr)) {
 425                                         *(ptr--) = 0;
 426                                 }
 427                                 if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 428                                         *(public_clientspos++) = '|';
 429                                         paddr = addrbuf;
 430                                         while (!IsEmptyStr(paddr) &&
 431                                                (public_clientspos < public_clientsend)){
 432                                                 *(public_clientspos++) = *(paddr++);
 433                                         }
 434                                 }
 435                         }
 436                 fclose(fp);
 437                 pc_timestamp = time(NULL);
 438                 end_critical_section(S_PUBLIC_CLIENTS);
 439         }
 440
 441         syslog(LOG_DEBUG, "Checking whether %s is a local or public client\n",
 442                 CC->cs_addr);
 443         for (i=0; i<num_parms(public_clients); ++i) {
 444                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 445                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 446                         syslog(LOG_DEBUG, "... yes its local.\n");
 447                         return(1);
 448                 }
 449         }
 450
 451         /* No hits.  This is not a public client. */
 452         syslog(LOG_DEBUG, "... no it isn't.\n");
 453         return(0);
 454 }
 455
 456
 457 /*
 458  * the client is identifying itself to the server
 459  */
 460 void cmd_iden(char *argbuf)
 461 {
 462         int dev_code;
 463         int cli_code;
 464         int rev_level;
 465         char desc[128];
 466         char from_host[128];
 467
 468         if (num_parms(argbuf)<4) {
 469                 cprintf("%d usage error\n", ERROR + ILLEGAL_VALUE);
 470                 return;
 471         }
 472
 473         dev_code = extract_int(argbuf,0);
 474         cli_code = extract_int(argbuf,1);
 475         rev_level = extract_int(argbuf,2);
 476         extract_token(desc, argbuf, 3, '|', sizeof desc);
 477
 478         safestrncpy(from_host, config.c_fqdn, sizeof from_host);
 479         from_host[sizeof from_host - 1] = 0;
 480         if (num_parms(argbuf)>=5) extract_token(from_host, argbuf, 4, '|', sizeof from_host);
 481
 482         CC->cs_clientdev = dev_code;
 483         CC->cs_clienttyp = cli_code;
 484         CC->cs_clientver = rev_level;
 485         safestrncpy(CC->cs_clientname, desc, sizeof CC->cs_clientname);
 486         CC->cs_clientname[31] = 0;
 487
 488         /* For local sockets and public clients, trust the hostname supplied by the client */
 489         if ( (CC->is_local_socket) || (is_public_client()) ) {
 490                 safestrncpy(CC->cs_host, from_host, sizeof CC->cs_host);
 491                 CC->cs_host[sizeof CC->cs_host - 1] = 0;
 492                 CC->cs_addr[0] = 0;
 493         }
 494
 495         syslog(LOG_NOTICE, "Client %d/%d/%01d.%02d (%s) from %s\n",
 496                 dev_code,
 497                 cli_code,
 498                 (rev_level / 100),
 499                 (rev_level % 100),
 500                 desc,
 501                 CC->cs_host
 502         );
 503         cprintf("%d Ok\n",CIT_OK);
 504 }
 505
 506 typedef const char *ccharp;
 507 /*
 508  * display system messages or help
 509  */
 510 void cmd_mesg(char *mname)
 511 {
 512         FILE *mfp;
 513         char targ[256];
 514         char buf[256];
 515         char buf2[256];
 516         char *dirs[2];
 517         DIR *dp;
 518         struct dirent *d;
 519
 520         extract_token(buf, mname, 0, '|', sizeof buf);
 521
 522         dirs[0] = strdup(ctdl_message_dir);
 523         dirs[1] = strdup(ctdl_hlp_dir);
 524
 525         snprintf(buf2, sizeof buf2, "%s.%d.%d",
 526                 buf, CC->cs_clientdev, CC->cs_clienttyp);
 527
 528         /* If the client requested "?" then produce a listing */
 529         if (!strcmp(buf, "?")) {
 530                 cprintf("%d %s\n", LISTING_FOLLOWS, buf);
 531                 dp = opendir(dirs[1]);
 532                 if (dp != NULL) {
 533                         while (d = readdir(dp), d != NULL) {
 534                                 if (d->d_name[0] != '.') {
 535                                         cprintf(" %s\n", d->d_name);
 536                                 }
 537                         }
 538                         closedir(dp);
 539                 }
 540                 cprintf("000\n");
 541                 free(dirs[0]);
 542                 free(dirs[1]);
 543                 return;
 544         }
 545
 546         /* Otherwise, look for the requested file by name. */
 547         else {
 548                 mesg_locate(targ, sizeof targ, buf2, 2, (const ccharp*)dirs);
 549                 if (IsEmptyStr(targ)) {
 550                         snprintf(buf2, sizeof buf2, "%s.%d",
 551                                                         buf, CC->cs_clientdev);
 552                         mesg_locate(targ, sizeof targ, buf2, 2,
 553                                     (const ccharp*)dirs);
 554                         if (IsEmptyStr(targ)) {
 555                                 mesg_locate(targ, sizeof targ, buf, 2,
 556                                             (const ccharp*)dirs);
 557                         }
 558                 }
 559         }
 560
 561         free(dirs[0]);
 562         free(dirs[1]);
 563
 564         if (IsEmptyStr(targ)) {
 565                 cprintf("%d '%s' not found.  (Searching in %s and %s)\n",
 566                         ERROR + FILE_NOT_FOUND,
 567                         mname,
 568                         ctdl_message_dir,
 569                         ctdl_hlp_dir
 570                 );
 571                 return;
 572         }
 573
 574         mfp = fopen(targ, "r");
 575         if (mfp==NULL) {
 576                 cprintf("%d Cannot open '%s': %s\n",
 577                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 578                 return;
 579         }
 580         cprintf("%d %s\n", LISTING_FOLLOWS,buf);
 581
 582         while (fgets(buf, (sizeof buf - 1), mfp) != NULL) {
 583                 buf[strlen(buf)-1] = 0;
 584                 do_help_subst(buf);
 585                 cprintf("%s\n",buf);
 586         }
 587
 588         fclose(mfp);
 589         cprintf("000\n");
 590 }
 591
 592
 593 /*
 594  * enter system messages or help
 595  */
 596 void cmd_emsg(char *mname)
 597 {
 598         FILE *mfp;
 599         char targ[256];
 600         char buf[256];
 601         char *dirs[2];
 602         int a;
 603
 604         unbuffer_output();
 605
 606         if (CtdlAccessCheck(ac_aide)) return;
 607
 608         extract_token(buf, mname, 0, '|', sizeof buf);
 609         for (a=0; !IsEmptyStr(&buf[a]); ++a) {          /* security measure */
 610                 if (buf[a] == '/') buf[a] = '.';
 611         }
 612
 613         dirs[0] = strdup(ctdl_message_dir);
 614         dirs[1] = strdup(ctdl_hlp_dir);
 615
 616         mesg_locate(targ, sizeof targ, buf, 2, (const ccharp*)dirs);
 617         free(dirs[0]);
 618         free(dirs[1]);
 619
 620         if (IsEmptyStr(targ)) {
 621                 snprintf(targ, sizeof targ,
 622                                  "%s/%s",
 623                                  ctdl_hlp_dir, buf);
 624         }
 625
 626         mfp = fopen(targ,"w");
 627         if (mfp==NULL) {
 628                 cprintf("%d Cannot open '%s': %s\n",
 629                         ERROR + INTERNAL_ERROR, targ, strerror(errno));
 630                 return;
 631         }
 632         cprintf("%d %s\n", SEND_LISTING, targ);
 633
 634         while (client_getln(buf, sizeof buf) >=0 && strcmp(buf, "000")) {
 635                 fprintf(mfp, "%s\n", buf);
 636         }
 637
 638         fclose(mfp);
 639 }
 640
 641
 642 /* Don't show the names of private rooms unless the viewing
 643  * user also knows the rooms.
 644  */
 645 void GenerateRoomDisplay(char *real_room,
 646                         CitContext *viewed,
 647                         CitContext *viewer) {
 648
 649         int ra;
 650
 651         strcpy(real_room, viewed->room.QRname);
 652         if (viewed->room.QRflags & QR_MAILBOX) {
 653                 strcpy(real_room, &real_room[11]);
 654         }
 655         if (viewed->room.QRflags & QR_PRIVATE) {
 656                 CtdlRoomAccess(&viewed->room, &viewer->user, &ra, NULL);
 657                 if ( (ra & UA_KNOWN) == 0) {
 658                         strcpy(real_room, " ");
 659                 }
 660         }
 661
 662         if (viewed->cs_flags & CS_CHAT) {
 663                 while (strlen(real_room) < 14) {
 664                         strcat(real_room, " ");
 665                 }
 666                 strcpy(&real_room[14], "<chat>");
 667         }
 668
 669 }
 670
 671 /*
 672  * Convenience function.
 673  */
 674 int CtdlAccessCheck(int required_level) {
 675
 676         if (CC->internal_pgm) return(0);
 677         if (required_level >= ac_internal) {
 678                 cprintf("%d This is not a user-level command.\n",
 679                         ERROR + HIGHER_ACCESS_REQUIRED);
 680                 return(-1);
 681         }
 682
 683         if ((required_level >= ac_logged_in_or_guest) && (CC->logged_in == 0) && (!config.c_guest_logins)) {
 684                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 685                 return(-1);
 686         }
 687
 688         if ((required_level >= ac_logged_in) && (CC->logged_in == 0)) {
 689                 cprintf("%d Not logged in.\n", ERROR + NOT_LOGGED_IN);
 690                 return(-1);
 691         }
 692
 693         if (CC->user.axlevel >= AxAideU) return(0);
 694         if (required_level >= ac_aide) {
 695                 cprintf("%d This command requires Aide access.\n",
 696                         ERROR + HIGHER_ACCESS_REQUIRED);
 697                 return(-1);
 698         }
 699
 700         if (is_room_aide()) return(0);
 701         if (required_level >= ac_room_aide) {
 702                 cprintf("%d This command requires Aide or Room Aide access.\n",
 703                         ERROR + HIGHER_ACCESS_REQUIRED);
 704                 return(-1);
 705         }
 706
 707         /* shhh ... succeed quietly */
 708         return(0);
 709 }
 710
 711
 712
 713 /*
 714  * Terminate another running session
 715  */
 716 void cmd_term(char *cmdbuf)
 717 {
 718         int session_num;
 719         int terminated = 0;
 720
 721         session_num = extract_int(cmdbuf, 0);
 722
 723         terminated = CtdlTerminateOtherSession(session_num);
 724
 725         if (terminated < 0) {
 726                 cprintf("%d You can't kill your own session.\n", ERROR + ILLEGAL_VALUE);
 727                 return;
 728         }
 729
 730         if (terminated & TERM_FOUND) {
 731                 if (terminated == TERM_KILLED) {
 732                         cprintf("%d Session terminated.\n", CIT_OK);
 733                 }
 734                 else {
 735                         cprintf("%d You are not allowed to do that.\n",
 736                                 ERROR + HIGHER_ACCESS_REQUIRED);
 737                 }
 738         }
 739         else {
 740                 cprintf("%d No such session.\n", ERROR + ILLEGAL_VALUE);
 741         }
 742 }
 743
 744
 745 /*
 746  * get the paginator prompt
 747  */
 748 void cmd_more(char *argbuf) {
 749         cprintf("%d %s\n", CIT_OK, config.c_moreprompt);
 750 }
 751
 752
 753 /*
 754  * echo
 755  */
 756 void cmd_echo(char *etext)
 757 {
 758         cprintf("%d %s\n", CIT_OK, etext);
 759 }
 760
 761
 762 /*
 763  * Perform privilege escalation for an internal program
 764  */
 765 void cmd_ipgm(char *argbuf)
 766 {
 767         int secret;
 768
 769         secret = extract_int(argbuf, 0);
 770
 771         /* For security reasons, we do NOT allow this command to run
 772          * over the network.  Local sockets only.
 773          */
 774         if (!CC->is_local_socket) {
 775                 sleep(5);
 776                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 777         }
 778         else if (secret == config.c_ipgm_secret) {
 779                 CC->internal_pgm = 1;
 780                 strcpy(CC->curr_user, "<internal program>");
 781                 CC->cs_flags = CC->cs_flags|CS_STEALTH;
 782                 cprintf("%d Authenticated as an internal program.\n", CIT_OK);
 783         }
 784         else {
 785                 sleep(5);
 786                 cprintf("%d Authentication failed.\n", ERROR + PASSWORD_REQUIRED);
 787                 syslog(LOG_ERR, "Warning: ipgm authentication failed.\n");
 788                 CC->kill_me = KILLME_AUTHFAILED;
 789         }
 790 }
 791
 792
 793 /*
 794  * Shut down the server
 795  */
 796 void cmd_down(char *argbuf) {
 797         char *Reply ="%d Shutting down server.  Goodbye.\n";
 798
 799         if (CtdlAccessCheck(ac_aide)) return;
 800
 801         if (!IsEmptyStr(argbuf))
 802         {
 803                 int state = CIT_OK;
 804                 restart_server = extract_int(argbuf, 0);
 805
 806                 if (restart_server > 0)
 807                 {
 808                         Reply = "%d citserver will now shut down and automatically restart.\n";
 809                 }
 810                 if ((restart_server > 0) && !running_as_daemon)
 811                 {
 812                         syslog(LOG_ERR, "The user requested restart, but not running as daemon! Geronimooooooo!\n");
 813                         Reply = "%d Warning: citserver is not running in daemon mode and is therefore unlikely to restart automatically.\n";
 814                         state = ERROR;
 815                 }
 816                 cprintf(Reply, state);
 817         }
 818         else
 819         {
 820                 cprintf(Reply, CIT_OK + SERVER_SHUTTING_DOWN);
 821         }
 822         CC->kill_me = KILLME_SERVER_SHUTTING_DOWN;
 823         server_shutting_down = 1;
 824 }
 825
 826
 827 /*
 828  * Halt the server without exiting the server process.
 829  */
 830 void cmd_halt(char *argbuf) {
 831
 832         if (CtdlAccessCheck(ac_aide)) return;
 833
 834         cprintf("%d Halting server.  Goodbye.\n", CIT_OK);
 835         server_shutting_down = 1;
 836         shutdown_and_halt = 1;
 837 }
 838
 839
 840 /*
 841  * Schedule or cancel a server shutdown
 842  */
 843 void cmd_scdn(char *argbuf)
 844 {
 845         int new_state;
 846         int state = CIT_OK;
 847         char *Reply = "%d %d\n";
 848
 849         if (CtdlAccessCheck(ac_aide)) return;
 850
 851         new_state = extract_int(argbuf, 0);
 852         if ((new_state == 2) || (new_state == 3))
 853         {
 854                 restart_server = 1;
 855                 if (!running_as_daemon)
 856                 {
 857                         syslog(LOG_ERR, "The user requested restart, but not running as deamon! Geronimooooooo!\n");
 858                         Reply = "%d %d Warning, not running in deamon mode. maybe we will come up again, but don't lean on it.\n";
 859                         state = ERROR;
 860                 }
 861
 862                 restart_server = extract_int(argbuf, 0);
 863                 new_state -= 2;
 864         }
 865         if ((new_state == 0) || (new_state == 1)) {
 866                 ScheduledShutdown = new_state;
 867         }
 868         cprintf(Reply, state, ScheduledShutdown);
 869 }
 870
 871
 872 /*
 873  * Set or unset asynchronous protocol mode
 874  */
 875 void cmd_asyn(char *argbuf)
 876 {
 877         int new_state;
 878
 879         new_state = extract_int(argbuf, 0);
 880         if ((new_state == 0) || (new_state == 1)) {
 881                 CC->is_async = new_state;
 882         }
 883         cprintf("%d %d\n", CIT_OK, CC->is_async);
 884 }
 885
 886
 887
 888 /*
 889  * Back-end function for starting a session
 890  */
 891 void begin_session(CitContext *con)
 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         if (!CC->is_local_socket) {
 918                 locate_host(con->cs_host, sizeof con->cs_host,
 919                         con->cs_addr, sizeof con->cs_addr,
 920                         con->client_socket
 921                 );
 922         }
 923         else {
 924                 con->cs_host[0] = 0;
 925                 con->cs_addr[0] = 0;
 926 #ifdef HAVE_STRUCT_UCRED
 927                 {
 928                         /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
 929                         struct ucred credentials;
 930                         socklen_t ucred_length = sizeof(struct ucred);
 931
 932                         /*fill in the user data structure */
 933                         if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
 934                                 syslog(LOG_NOTICE, "could obtain credentials from unix domain socket");
 935
 936                         }
 937                         else {
 938                                 /* the process ID of the process on the other side of the socket */
 939                                 /* credentials.pid; */
 940
 941                                 /* the effective UID of the process on the other side of the socket  */
 942                                 con->cs_UDSclientUID = credentials.uid;
 943
 944                                 /* the effective primary GID of the process on the other side of the socket */
 945                                 /* credentials.gid; */
 946
 947                                 /* To get supplemental groups, we will have to look them up in our account
 948                                    database, after a reverse lookup on the UID to get the account name.
 949                                    We can take this opportunity to check to see if this is a legit account.
 950                                 */
 951                                 snprintf(con->cs_clientinfo, sizeof(con->cs_clientinfo),
 952                                          "PID: "F_PID_T"; UID: "F_UID_T"; GID: "F_XPID_T" ",
 953                                          credentials.pid,
 954                                          credentials.uid,
 955                                          credentials.gid);
 956                         }
 957                 }
 958 #endif
 959         }
 960         con->cs_flags = 0;
 961         con->upload_type = UPL_FILE;
 962         con->dl_is_net = 0;
 963
 964         con->nologin = 0;
 965         if (((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions)) || CtdlWantSingleUser()) {
 966                 con->nologin = 1;
 967         }
 968
 969         if (!CC->is_local_socket) {
 970                 syslog(LOG_NOTICE, "Session (%s) started from %s (%s).\n", con->ServiceName, con->cs_host, con->cs_addr);
 971         }
 972         else {
 973                 syslog(LOG_NOTICE, "Session (%s) started via local socket UID:%d.\n", con->ServiceName, con->cs_UDSclientUID);
 974         }
 975
 976         /* Run any session startup routines registered by loadable modules */
 977         PerformSessionHooks(EVT_START);
 978 }
 979
 980
 981 void citproto_begin_session() {
 982         if (CC->nologin==1) {
 983                 cprintf("%d %s: Too many users are already online (maximum is %d)\n",
 984                         ERROR + MAX_SESSIONS_EXCEEDED,
 985                         config.c_nodename, config.c_maxsessions
 986                 );
 987                 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
 988         }
 989         else {
 990                 cprintf("%d %s Citadel server ready.\n", CIT_OK, config.c_nodename);
 991                 CC->can_receive_im = 1;
 992         }
 993 }
 994
 995
 996 void citproto_begin_admin_session() {
 997         CC->internal_pgm = 1;
 998         cprintf("%d %s Citadel server ADMIN CONNECTION ready.\n", CIT_OK, config.c_nodename);
 999 }
1000
1001
1002 void cmd_noop(char *argbuf)
1003 {
1004         cprintf("%d%cok\n", CIT_OK, CtdlCheckExpress() );
1005 }
1006
1007
1008 void cmd_qnop(char *argbuf)
1009 {
1010         /* do nothing, this command returns no response */
1011 }
1012
1013
1014 void cmd_quit(char *argbuf)
1015 {
1016         cprintf("%d Goodbye.\n", CIT_OK);
1017         CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
1018 }
1019
1020
1021 void cmd_lout(char *argbuf)
1022 {
1023         if (CC->logged_in)
1024                 CtdlUserLogout();
1025         cprintf("%d logged out.\n", CIT_OK);
1026 }
1027
1028
1029 /*
1030  * This loop recognizes all server commands.
1031  */
1032 void do_command_loop(void) {
1033         char cmdbuf[SIZ];
1034
1035         time(&CC->lastcmd);
1036         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
1037         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
1038                 syslog(LOG_ERR, "Citadel client disconnected: ending session.\n");
1039                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
1040                 return;
1041         }
1042
1043         /* Log the server command, but don't show passwords... */
1044         if ( (strncasecmp(cmdbuf, "PASS", 4)) && (strncasecmp(cmdbuf, "SETP", 4)) ) {
1045                 syslog(LOG_INFO, "[%d][%s(%ld)] %s",
1046                         CC->cs_pid, CC->curr_user, CC->user.usernum, cmdbuf
1047                 );
1048         }
1049         else {
1050                 syslog(LOG_INFO, "[%d][%s(%ld)] <password command hidden from log>",
1051                         CC->cs_pid, CC->curr_user, CC->user.usernum
1052                 );
1053         }
1054
1055         buffer_output();
1056
1057         /*
1058          * Let other clients see the last command we executed, and
1059          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
1060          */
1061         if ( (strncasecmp(cmdbuf, "NOOP", 4))
1062            && (strncasecmp(cmdbuf, "QNOP", 4))
1063            && (strncasecmp(cmdbuf, "PEXP", 4))
1064            && (strncasecmp(cmdbuf, "GEXP", 4))
1065            && (strncasecmp(cmdbuf, "RWHO", 4))
1066            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
1067                 strcpy(CC->lastcmdname, "    ");
1068                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
1069                 time(&CC->lastidle);
1070         }
1071
1072         if ((strncasecmp(cmdbuf, "ENT0", 4))
1073            && (strncasecmp(cmdbuf, "MESG", 4))
1074            && (strncasecmp(cmdbuf, "MSGS", 4)))
1075         {
1076            CC->cs_flags &= ~CS_POSTING;
1077         }
1078
1079         if (!DLoader_Exec_Cmd(cmdbuf)) {
1080                 cprintf("%d Unrecognized or unsupported command.\n", ERROR + CMD_NOT_SUPPORTED);
1081         }
1082
1083         unbuffer_output();
1084
1085         /* Run any after-each-command routines registered by modules */
1086         PerformSessionHooks(EVT_CMD);
1087 }
1088
1089
1090 /*
1091  * This loop performs all asynchronous functions.
1092  */
1093 void do_async_loop(void) {
1094         PerformSessionHooks(EVT_ASYNC);
1095 }
1096
1097
1098 /*****************************************************************************/
1099 /*                      MODULE INITIALIZATION STUFF                          */
1100 /*****************************************************************************/
1101
1102 CTDL_MODULE_INIT(citserver)
1103 {
1104         if (!threading) {
1105                 CtdlRegisterProtoHook(cmd_noop, "NOOP", "no operation");
1106                 CtdlRegisterProtoHook(cmd_qnop, "QNOP", "no operation with no response");
1107                 CtdlRegisterProtoHook(cmd_quit, "QUIT", "log out and disconnect from server");
1108                 CtdlRegisterProtoHook(cmd_lout, "LOUT", "log out but do not disconnect from server");
1109                 CtdlRegisterProtoHook(cmd_asyn, "ASYN", "enable asynchronous server responses");
1110                 CtdlRegisterProtoHook(cmd_info, "INFO", "fetch server capabilities and configuration");
1111                 CtdlRegisterProtoHook(cmd_mesg, "MESG", "fetch system banners");
1112                 CtdlRegisterProtoHook(cmd_emsg, "EMSG", "submit system banners");
1113                 CtdlRegisterProtoHook(cmd_echo, "ECHO", "echo text back to the client");
1114                 CtdlRegisterProtoHook(cmd_more, "MORE", "fetch the paginator prompt");
1115                 CtdlRegisterProtoHook(cmd_iden, "IDEN", "identify the client software and location");
1116                 CtdlRegisterProtoHook(cmd_ipgm, "IPGM", "perform privilege escalation for internal programs");
1117                 CtdlRegisterProtoHook(cmd_term, "TERM", "terminate another running session");
1118                 CtdlRegisterProtoHook(cmd_down, "DOWN", "perform a server shutdown");
1119                 CtdlRegisterProtoHook(cmd_halt, "HALT", "halt the server without exiting the server process");
1120                 CtdlRegisterProtoHook(cmd_scdn, "SCDN", "schedule or cancel a server shutdown");
1121                 CtdlRegisterProtoHook(cmd_time, "TIME", "fetch the date and time from the server");
1122         }
1123         /* return our id for the Log */
1124         return "citserver";
1125 }