citadel/citserver.c

   1 /*
   2  * Main source module for the Citadel server
   3  *
   4  * Copyright (c) 1987-2011 by the citadel.org team
   5  *
   6  * This program is open source software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 3.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include "sysdep.h"
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <fcntl.h>
  20 #include <signal.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23
  24 #if TIME_WITH_SYS_TIME
  25 # include <sys/time.h>
  26 # include <time.h>
  27 #else
  28 # if HAVE_SYS_TIME_H
  29 #  include <sys/time.h>
  30 # else
  31 #  include <time.h>
  32 # endif
  33 #endif
  34
  35 #if HAVE_BACKTRACE
  36 #include <execinfo.h>
  37 #endif
  38
  39 #include <ctype.h>
  40 #include <string.h>
  41 #include <errno.h>
  42 #include <limits.h>
  43 #include <netdb.h>
  44 #include <sys/types.h>
  45 #include <sys/socket.h>
  46 #include <netinet/in.h>
  47 #include <arpa/inet.h>
  48 #include <libcitadel.h>
  49 #include "citadel.h"
  50 #include "server.h"
  51 #include "sysdep_decls.h"
  52 #include "threads.h"
  53 #include "citserver.h"
  54 #include "config.h"
  55 #include "database.h"
  56 #include "housekeeping.h"
  57 #include "user_ops.h"
  58 #include "msgbase.h"
  59 #include "support.h"
  60 #include "locate_host.h"
  61 #include "room_ops.h"
  62 #include "control.h"
  63 #include "euidindex.h"
  64 #include "context.h"
  65 #include "svn_revision.h"
  66 #include "ctdl_module.h"
  67
  68 char *unique_session_numbers;
  69 int ScheduledShutdown = 0;
  70 time_t server_startup_time;
  71 int panic_fd;
  72 int openid_level_supported = 0;
  73
  74 /*
  75  * print the actual stack frame.
  76  */
  77 void cit_backtrace(void)
  78 {
  79 #ifdef HAVE_BACKTRACE
  80         void *stack_frames[50];
  81         size_t size, i;
  82         char **strings;
  83
  84
  85         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
  86         strings = backtrace_symbols(stack_frames, size);
  87         for (i = 0; i < size; i++) {
  88                 if (strings != NULL)
  89                         syslog(LOG_ALERT, "%s\n", strings[i]);
  90                 else
  91                         syslog(LOG_ALERT, "%p\n", stack_frames[i]);
  92         }
  93         free(strings);
  94 #endif
  95 }
  96
  97 void cit_oneline_backtrace(void)
  98 {
  99 #ifdef HAVE_BACKTRACE
 100         void *stack_frames[50];
 101         size_t size, i;
 102         char **strings;
 103         StrBuf *Buf;
 104
 105         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 106         strings = backtrace_symbols(stack_frames, size);
 107         if (size > 0)
 108         {
 109                 Buf = NewStrBuf();
 110                 for (i = 1; i < size; i++) {
 111                         if (strings != NULL)
 112                                 StrBufAppendPrintf(Buf, "%s : ", strings[i]);
 113                         else
 114                                 StrBufAppendPrintf(Buf, "%p : ", stack_frames[i]);
 115                 }
 116                 free(strings);
 117                 syslog(LOG_ALERT, "%s\n", ChrPtr(Buf));
 118                 FreeStrBuf(&Buf);
 119         }
 120 #endif
 121 }
 122
 123 /*
 124  * print the actual stack frame.
 125  */
 126 void cit_panic_backtrace(int SigNum)
 127 {
 128 #ifdef HAVE_BACKTRACE
 129         void *stack_frames[10];
 130         size_t size, i;
 131         char **strings;
 132
 133         printf("caught signal 11\n");
 134         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 135         strings = backtrace_symbols(stack_frames, size);
 136         for (i = 0; i < size; i++) {
 137                 if (strings != NULL)
 138                         syslog(LOG_ALERT, "%s\n", strings[i]);
 139                 else
 140                         syslog(LOG_ALERT, "%p\n", stack_frames[i]);
 141         }
 142         free(strings);
 143 #endif
 144         exit(-1);
 145 }
 146
 147 /*
 148  * Various things that need to be initialized at startup
 149  */
 150 void master_startup(void) {
 151         struct timeval tv;
 152         unsigned int seed;
 153         FILE *urandom;
 154         struct ctdlroom qrbuf;
 155         int rv;
 156
 157         syslog(LOG_DEBUG, "master_startup() started\n");
 158         time(&server_startup_time);
 159         get_config();
 160
 161         syslog(LOG_INFO, "Opening databases\n");
 162         open_databases();
 163         check_ref_counts();
 164
 165         syslog(LOG_INFO, "Creating base rooms (if necessary)\n");
 166         CtdlCreateRoom(config.c_baseroom,       0, "", 0, 1, 0, VIEW_BBS);
 167         CtdlCreateRoom(AIDEROOM,                3, "", 0, 1, 0, VIEW_BBS);
 168         CtdlCreateRoom(SYSCONFIGROOM,           3, "", 0, 1, 0, VIEW_BBS);
 169         CtdlCreateRoom(config.c_twitroom,       0, "", 0, 1, 0, VIEW_BBS);
 170
 171         /* The "Local System Configuration" room doesn't need to be visible */
 172         if (CtdlGetRoomLock(&qrbuf, SYSCONFIGROOM) == 0) {
 173                 qrbuf.QRflags2 |= QR2_SYSTEM;
 174                 CtdlPutRoomLock(&qrbuf);
 175         }
 176
 177         /* Aide needs to be public postable, else we're not RFC conformant. */
 178         if (CtdlGetRoomLock(&qrbuf, AIDEROOM) == 0) {
 179                 qrbuf.QRflags2 |= QR2_SMTP_PUBLIC;
 180                 CtdlPutRoomLock(&qrbuf);
 181         }
 182
 183         syslog(LOG_INFO, "Seeding the pseudo-random number generator...\n");
 184         urandom = fopen("/dev/urandom", "r");
 185         if (urandom != NULL) {
 186                 rv = fread(&seed, sizeof seed, 1, urandom);
 187                 if (rv == -1)
 188                         syslog(LOG_EMERG, "failed to read random seed: %s\n",
 189                                strerror(errno));
 190                 fclose(urandom);
 191         }
 192         else {
 193                 gettimeofday(&tv, NULL);
 194                 seed = tv.tv_usec;
 195         }
 196         srand(seed);
 197         srandom(seed);
 198
 199         put_config();
 200
 201         syslog(LOG_DEBUG, "master_startup() finished\n");
 202 }
 203
 204
 205 /*
 206  * Cleanup routine to be called when the server is shutting down.
 207  */
 208 void master_cleanup(int exitcode) {
 209         struct CleanupFunctionHook *fcn;
 210         static int already_cleaning_up = 0;
 211
 212         if (already_cleaning_up) while(1) usleep(1000000);
 213         already_cleaning_up = 1;
 214
 215         /* Run any cleanup routines registered by loadable modules */
 216         for (fcn = CleanupHookTable; fcn != NULL; fcn = fcn->next) {
 217                 (*fcn->h_function_pointer)();
 218         }
 219
 220         /* Close the AdjRefCount queue file */
 221         AdjRefCount(-1, 0);
 222
 223         /* Do system-dependent stuff */
 224         sysdep_master_cleanup();
 225
 226         /* Close databases */
 227         syslog(LOG_INFO, "Closing databases\n");
 228         close_databases();
 229
 230         /* If the operator requested a halt but not an exit, halt here. */
 231         if (shutdown_and_halt) {
 232                 syslog(LOG_NOTICE, "citserver: Halting server without exiting.\n");
 233                 fflush(stdout); fflush(stderr);
 234                 while(1) {
 235                         sleep(32767);
 236                 }
 237         }
 238
 239         release_control();
 240
 241         /* Now go away. */
 242         syslog(LOG_NOTICE, "citserver: Exiting with status %d\n", exitcode);
 243         fflush(stdout); fflush(stderr);
 244
 245         if (restart_server != 0)
 246                 exit(1);
 247         if ((running_as_daemon != 0) && ((exitcode == 0) ))
 248                 exitcode = CTDLEXIT_SHUTDOWN;
 249         exit(exitcode);
 250 }
 251
 252
 253
 254 /*
 255  * returns an asterisk if there are any instant messages waiting,
 256  * space otherwise.
 257  */
 258 char CtdlCheckExpress(void) {
 259         if (CC->FirstExpressMessage == NULL) {
 260                 return(' ');
 261         }
 262         else {
 263                 return('*');
 264         }
 265 }
 266
 267
 268 /*
 269  * Check originating host against the public_clients file.  This determines
 270  * whether the client is allowed to change the hostname for this session
 271  * (for example, to show the location of the user rather than the location
 272  * of the client).
 273  */
 274 int CtdlIsPublicClient(void)
 275 {
 276         char buf[1024];
 277         char addrbuf[1024];
 278         FILE *fp;
 279         int i;
 280         char *public_clientspos;
 281         char *public_clientsend;
 282         char *paddr = NULL;
 283         struct stat statbuf;
 284         static time_t pc_timestamp = 0;
 285         static char public_clients[SIZ];
 286         static char public_clients_file[SIZ];
 287
 288 #define LOCALHOSTSTR "127.0.0.1"
 289
 290         snprintf(public_clients_file, sizeof public_clients_file, "%s/public_clients", ctdl_etc_dir);
 291
 292         /*
 293          * Check the time stamp on the public_clients file.  If it's been
 294          * updated since the last time we were here (or if this is the first
 295          * time we've been through the loop), read its contents and learn
 296          * the IP addresses of the listed hosts.
 297          */
 298         if (stat(public_clients_file, &statbuf) != 0) {
 299                 /* No public_clients file exists, so bail out */
 300                 syslog(LOG_WARNING, "Warning: '%s' does not exist\n",
 301                                 public_clients_file);
 302                 return(0);
 303         }
 304
 305         if (statbuf.st_mtime > pc_timestamp) {
 306                 begin_critical_section(S_PUBLIC_CLIENTS);
 307                 syslog(LOG_INFO, "Loading %s\n", public_clients_file);
 308
 309                 public_clientspos = &public_clients[0];
 310                 public_clientsend = public_clientspos + SIZ;
 311                 safestrncpy(public_clientspos, LOCALHOSTSTR, sizeof public_clients);
 312                 public_clientspos += sizeof(LOCALHOSTSTR) - 1;
 313
 314                 if (hostname_to_dotted_quad(addrbuf, config.c_fqdn) == 0) {
 315                         *(public_clientspos++) = '|';
 316                         paddr = &addrbuf[0];
 317                         while (!IsEmptyStr (paddr) &&
 318                                (public_clientspos < public_clientsend))
 319                                 *(public_clientspos++) = *(paddr++);
 320                 }
 321
 322                 fp = fopen(public_clients_file, "r");
 323                 if (fp != NULL)
 324                         while ((fgets(buf, sizeof buf, fp)!=NULL) &&
 325                                (public_clientspos < public_clientsend)){
 326                                 char *ptr;
 327                                 ptr = buf;
 328                                 while (!IsEmptyStr(ptr)) {
 329                                         if (*ptr == '#') {
 330                                                 *ptr = 0;
 331                                                 break;
 332                                         }
 333                                 else ptr++;
 334                                 }
 335                                 ptr--;
 336                                 while (ptr>buf && isspace(*ptr)) {
 337                                         *(ptr--) = 0;
 338                                 }
 339                                 if (hostname_to_dotted_quad(addrbuf, buf) == 0) {
 340                                         *(public_clientspos++) = '|';
 341                                         paddr = addrbuf;
 342                                         while (!IsEmptyStr(paddr) &&
 343                                                (public_clientspos < public_clientsend)){
 344                                                 *(public_clientspos++) = *(paddr++);
 345                                         }
 346                                 }
 347                         }
 348                 if (fp != NULL) fclose(fp);
 349                 pc_timestamp = time(NULL);
 350                 end_critical_section(S_PUBLIC_CLIENTS);
 351         }
 352
 353         syslog(LOG_DEBUG, "Checking whether %s is a local or public client\n",
 354                 CC->cs_addr);
 355         for (i=0; i<num_parms(public_clients); ++i) {
 356                 extract_token(addrbuf, public_clients, i, '|', sizeof addrbuf);
 357                 if (!strcasecmp(CC->cs_addr, addrbuf)) {
 358                         syslog(LOG_DEBUG, "... yes its local.\n");
 359                         return(1);
 360                 }
 361         }
 362
 363         /* No hits.  This is not a public client. */
 364         syslog(LOG_DEBUG, "... no it isn't.\n");
 365         return(0);
 366 }
 367
 368
 369
 370
 371
 372 /*
 373  * Back-end function for starting a session
 374  */
 375 void begin_session(CitContext *con)
 376 {
 377         /*
 378          * Initialize some variables specific to our context.
 379          */
 380         con->logged_in = 0;
 381         con->internal_pgm = 0;
 382         con->download_fp = NULL;
 383         con->upload_fp = NULL;
 384         con->cached_msglist = NULL;
 385         con->cached_num_msgs = 0;
 386         con->FirstExpressMessage = NULL;
 387         time(&con->lastcmd);
 388         time(&con->lastidle);
 389         strcpy(con->lastcmdname, "    ");
 390         strcpy(con->cs_clientname, "(unknown)");
 391         strcpy(con->curr_user, NLI);
 392         *con->net_node = '\0';
 393         *con->fake_username = '\0';
 394         *con->fake_hostname = '\0';
 395         *con->fake_roomname = '\0';
 396         *con->cs_clientinfo = '\0';
 397         safestrncpy(con->cs_host, config.c_fqdn, sizeof con->cs_host);
 398         safestrncpy(con->cs_addr, "", sizeof con->cs_addr);
 399         con->cs_UDSclientUID = -1;
 400         con->cs_host[sizeof con->cs_host - 1] = 0;
 401         if (!CC->is_local_socket) {
 402                 locate_host(con->cs_host, sizeof con->cs_host,
 403                         con->cs_addr, sizeof con->cs_addr,
 404                         con->client_socket
 405                 );
 406         }
 407         else {
 408                 con->cs_host[0] = 0;
 409                 con->cs_addr[0] = 0;
 410 #ifdef HAVE_STRUCT_UCRED
 411                 {
 412                         /* as http://www.wsinnovations.com/softeng/articles/uds.html told us... */
 413                         struct ucred credentials;
 414                         socklen_t ucred_length = sizeof(struct ucred);
 415
 416                         /*fill in the user data structure */
 417                         if(getsockopt(con->client_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &ucred_length)) {
 418                                 syslog(LOG_NOTICE, "could obtain credentials from unix domain socket");
 419
 420                         }
 421                         else {
 422                                 /* the process ID of the process on the other side of the socket */
 423                                 /* credentials.pid; */
 424
 425                                 /* the effective UID of the process on the other side of the socket  */
 426                                 con->cs_UDSclientUID = credentials.uid;
 427
 428                                 /* the effective primary GID of the process on the other side of the socket */
 429                                 /* credentials.gid; */
 430
 431                                 /* To get supplemental groups, we will have to look them up in our account
 432                                    database, after a reverse lookup on the UID to get the account name.
 433                                    We can take this opportunity to check to see if this is a legit account.
 434                                 */
 435                                 snprintf(con->cs_clientinfo, sizeof(con->cs_clientinfo),
 436                                          "PID: "F_PID_T"; UID: "F_UID_T"; GID: "F_XPID_T" ",
 437                                          credentials.pid,
 438                                          credentials.uid,
 439                                          credentials.gid);
 440                         }
 441                 }
 442 #endif
 443         }
 444         con->cs_flags = 0;
 445         con->upload_type = UPL_FILE;
 446         con->dl_is_net = 0;
 447
 448         con->nologin = 0;
 449         if (((config.c_maxsessions > 0)&&(num_sessions > config.c_maxsessions)) || CtdlWantSingleUser()) {
 450                 con->nologin = 1;
 451         }
 452
 453         if (!CC->is_local_socket) {
 454                 syslog(LOG_NOTICE, "Session (%s) started from %s (%s).\n", con->ServiceName, con->cs_host, con->cs_addr);
 455         }
 456         else {
 457                 syslog(LOG_NOTICE, "Session (%s) started via local socket UID:%d.\n", con->ServiceName, con->cs_UDSclientUID);
 458         }
 459
 460         /* Run any session startup routines registered by loadable modules */
 461         PerformSessionHooks(EVT_START);
 462 }
 463
 464
 465 void citproto_begin_session() {
 466         if (CC->nologin==1) {
 467                 cprintf("%d %s: Too many users are already online (maximum is %d)\n",
 468                         ERROR + MAX_SESSIONS_EXCEEDED,
 469                         config.c_nodename, config.c_maxsessions
 470                 );
 471                 CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
 472         }
 473         else {
 474                 cprintf("%d %s Citadel server ready.\n", CIT_OK, config.c_nodename);
 475                 CC->can_receive_im = 1;
 476         }
 477 }
 478
 479
 480 void citproto_begin_admin_session() {
 481         CC->internal_pgm = 1;
 482         cprintf("%d %s Citadel server ADMIN CONNECTION ready.\n", CIT_OK, config.c_nodename);
 483 }
 484
 485
 486
 487
 488 /*
 489  * This loop recognizes all server commands.
 490  */
 491 void do_command_loop(void) {
 492         char cmdbuf[SIZ];
 493
 494         time(&CC->lastcmd);
 495         memset(cmdbuf, 0, sizeof cmdbuf); /* Clear it, just in case */
 496         if (client_getln(cmdbuf, sizeof cmdbuf) < 1) {
 497                 syslog(LOG_ERR, "Citadel client disconnected: ending session.\n");
 498                 CC->kill_me = KILLME_CLIENT_DISCONNECTED;
 499                 return;
 500         }
 501
 502         /* Log the server command, but don't show passwords... */
 503         if ( (strncasecmp(cmdbuf, "PASS", 4)) && (strncasecmp(cmdbuf, "SETP", 4)) ) {
 504                 syslog(LOG_INFO, "[%d][%s(%ld)] %s",
 505                         CC->cs_pid, CC->curr_user, CC->user.usernum, cmdbuf
 506                 );
 507         }
 508         else {
 509                 syslog(LOG_INFO, "[%d][%s(%ld)] <password command hidden from log>",
 510                         CC->cs_pid, CC->curr_user, CC->user.usernum
 511                 );
 512         }
 513
 514         buffer_output();
 515
 516         /*
 517          * Let other clients see the last command we executed, and
 518          * update the idle time, but not NOOP, QNOP, PEXP, GEXP, RWHO, or TIME.
 519          */
 520         if ( (strncasecmp(cmdbuf, "NOOP", 4))
 521            && (strncasecmp(cmdbuf, "QNOP", 4))
 522            && (strncasecmp(cmdbuf, "PEXP", 4))
 523            && (strncasecmp(cmdbuf, "GEXP", 4))
 524            && (strncasecmp(cmdbuf, "RWHO", 4))
 525            && (strncasecmp(cmdbuf, "TIME", 4)) ) {
 526                 strcpy(CC->lastcmdname, "    ");
 527                 safestrncpy(CC->lastcmdname, cmdbuf, sizeof(CC->lastcmdname));
 528                 time(&CC->lastidle);
 529         }
 530
 531         if ((strncasecmp(cmdbuf, "ENT0", 4))
 532            && (strncasecmp(cmdbuf, "MESG", 4))
 533            && (strncasecmp(cmdbuf, "MSGS", 4)))
 534         {
 535            CC->cs_flags &= ~CS_POSTING;
 536         }
 537
 538         if (!DLoader_Exec_Cmd(cmdbuf)) {
 539                 cprintf("%d Unrecognized or unsupported command.\n", ERROR + CMD_NOT_SUPPORTED);
 540         }
 541
 542         unbuffer_output();
 543
 544         /* Run any after-each-command routines registered by modules */
 545         PerformSessionHooks(EVT_CMD);
 546 }
 547
 548
 549 /*
 550  * This loop performs all asynchronous functions.
 551  */
 552 void do_async_loop(void) {
 553         PerformSessionHooks(EVT_ASYNC);
 554 }
 555