citadel/server/sysdep.c

   1 // Citadel "system dependent" stuff.
   2 //
   3 // Here's where we (hopefully) have most parts of the Citadel server that
   4 // might need tweaking when run on different operating system variants.
   5 //
   6 // Copyright (c) 1987-2023 by the citadel.org team
   7 //
   8 // This program is open source software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License, version 3.
  10
  11 #include "sysdep.h"
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <sys/stat.h>
  15 #include <errno.h>
  16 #include <signal.h>
  17 #include <stdio.h>
  18 #include <syslog.h>
  19 #include <sys/syslog.h>
  20 #include <execinfo.h>
  21 #include <netdb.h>
  22 #include <sys/un.h>
  23 #include <sys/types.h>
  24 #include <sys/socket.h>
  25 #include <netinet/in.h>
  26 #include <arpa/inet.h>
  27 #include <netinet/tcp.h>
  28 #include <arpa/inet.h>
  29 #define SHOW_ME_VAPPEND_PRINTF
  30 #include <libcitadel.h>
  31 #include "citserver.h"
  32 #include "config.h"
  33 #include "ctdl_module.h"
  34 #include "sysdep_decls.h"
  35 #include "modules/crypto/serv_crypto.h" // Needed for init_ssl, client_write_ssl, client_read_ssl
  36 #include "housekeeping.h"
  37 #include "context.h"
  38
  39 // Signal handler to shut down the server.
  40 volatile int exit_signal = 0;
  41 volatile int shutdown_and_halt = 0;
  42 volatile int restart_server = 0;
  43 volatile int running_as_daemon = 0;
  44
  45
  46 static RETSIGTYPE signal_cleanup(int signum) {
  47         syslog(LOG_DEBUG, "sysdep: caught signal %d", signum);
  48         signal(signum, SIG_DFL);
  49         exit_signal = signum;
  50         server_shutting_down = 1;
  51 }
  52
  53
  54 // Some initialization stuff...
  55 void init_sysdep(void) {
  56         sigset_t set;
  57
  58         // Avoid vulnerabilities related to FD_SETSIZE if we can.
  59 #ifdef FD_SETSIZE
  60 #ifdef RLIMIT_NOFILE
  61         struct rlimit rl;
  62         getrlimit(RLIMIT_NOFILE, &rl);
  63         rl.rlim_cur = FD_SETSIZE;
  64         rl.rlim_max = FD_SETSIZE;
  65         setrlimit(RLIMIT_NOFILE, &rl);
  66 #endif
  67 #endif
  68
  69         // If we've got OpenSSL, we're going to use it.
  70 #ifdef HAVE_OPENSSL
  71         init_ssl();
  72 #endif
  73
  74         if (pthread_key_create(&ThreadKey, NULL) != 0) {                        // TSD for threads
  75                 syslog(LOG_ERR, "pthread_key_create() : %m");
  76                 exit(CTDLEXIT_THREAD);
  77         }
  78
  79         if (pthread_key_create(&MyConKey, NULL) != 0) {                         // TSD for sessions
  80                 syslog(LOG_CRIT, "sysdep: can't create TSD key: %m");
  81                 exit(CTDLEXIT_THREAD);
  82         }
  83
  84         // Interript, hangup, and terminate signals should cause the server to shut down.
  85         sigemptyset(&set);
  86         sigaddset(&set, SIGINT);
  87         sigaddset(&set, SIGHUP);
  88         sigaddset(&set, SIGTERM);
  89         sigaddset(&set, SIGSEGV);
  90         sigprocmask(SIG_UNBLOCK, &set, NULL);
  91
  92         signal(SIGINT, signal_cleanup);
  93         signal(SIGHUP, signal_cleanup);
  94         signal(SIGTERM, signal_cleanup);
  95         signal(SIGSEGV, signal_cleanup);
  96
  97         // Do not shut down the server on broken pipe signals, otherwise the
  98         // whole Citadel service would come down whenever a single client
  99         // socket breaks.
 100         signal(SIGPIPE, SIG_IGN);
 101 }
 102
 103
 104 // This is a generic function to set up a master socket for listening on
 105 // a TCP port.  The server shuts down if the bind fails.  (IPv4/IPv6 version)
 106 //
 107 // ip_addr      IP address to bind
 108 // port_number  port number to bind
 109 // queue_len    number of incoming connections to allow in the queue
 110 int ctdl_tcp_server(char *ip_addr, int port_number, int queue_len) {
 111         struct protoent *p;
 112         struct sockaddr_in6 sin6;
 113         struct sockaddr_in sin4;
 114         int s, i, b;
 115         int ip_version = 6;
 116
 117         memset(&sin6, 0, sizeof(sin6));
 118         memset(&sin4, 0, sizeof(sin4));
 119         sin6.sin6_family = AF_INET6;
 120         sin4.sin_family = AF_INET;
 121
 122         if (    (ip_addr == NULL)                                                       // any IPv6
 123                 || (IsEmptyStr(ip_addr))
 124                 || (!strcmp(ip_addr, "*"))
 125         ) {
 126                 ip_version = 6;
 127                 sin6.sin6_addr = in6addr_any;
 128         }
 129         else if (!strcmp(ip_addr, "0.0.0.0")) {                                         // any IPv4
 130                 ip_version = 4;
 131                 sin4.sin_addr.s_addr = INADDR_ANY;
 132         }
 133         else if ((strchr(ip_addr, '.')) && (!strchr(ip_addr, ':'))) {                   // specific IPv4
 134                 ip_version = 4;
 135                 if (inet_pton(AF_INET, ip_addr, &sin4.sin_addr) <= 0) {
 136                         syslog(LOG_ALERT, "tcpserver: inet_pton: %m");
 137                         return (-1);
 138                 }
 139         }
 140         else {                                                                          // specific IPv6
 141                 ip_version = 6;
 142                 if (inet_pton(AF_INET6, ip_addr, &sin6.sin6_addr) <= 0) {
 143                         syslog(LOG_ALERT, "tcpserver: inet_pton: %m");
 144                         return (-1);
 145                 }
 146         }
 147
 148         if (port_number == 0) {
 149                 syslog(LOG_ALERT, "tcpserver: no port number was specified");
 150                 return (-1);
 151         }
 152         sin6.sin6_port = htons((u_short) port_number);
 153         sin4.sin_port = htons((u_short) port_number);
 154
 155         p = getprotobyname("tcp");
 156         if (p == NULL) {
 157                 syslog(LOG_ALERT, "tcpserver: getprotobyname: %m");
 158                 return (-1);
 159         }
 160
 161         s = socket( ((ip_version == 6) ? PF_INET6 : PF_INET), SOCK_STREAM, (p->p_proto));
 162         if (s < 0) {
 163                 syslog(LOG_ALERT, "tcpserver: socket: %m");
 164                 return (-1);
 165         }
 166         // Set some socket options that make sense.
 167         i = 1;
 168         setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 169
 170         if (ip_version == 6) {
 171                 b = bind(s, (struct sockaddr *) &sin6, sizeof(sin6));
 172         }
 173         else {
 174                 b = bind(s, (struct sockaddr *) &sin4, sizeof(sin4));
 175         }
 176
 177         if (b < 0) {
 178                 syslog(LOG_ALERT, "tcpserver: bind: %m");
 179                 return (-1);
 180         }
 181
 182         fcntl(s, F_SETFL, O_NONBLOCK);
 183
 184         if (listen(s, ((queue_len >= 5) ? queue_len : 5) ) < 0) {
 185                 syslog(LOG_ALERT, "tcpserver: listen: %m");
 186                 return (-1);
 187         }
 188         return (s);
 189 }
 190
 191
 192 // Create a Unix domain socket and listen on it
 193 int ctdl_uds_server(char *sockpath, int queue_len) {
 194         struct sockaddr_un addr;
 195         int s;
 196         int i;
 197         int actual_queue_len;
 198 #ifdef HAVE_STRUCT_UCRED
 199         int passcred = 1;
 200 #endif
 201
 202         actual_queue_len = queue_len;
 203         if (actual_queue_len < 5) actual_queue_len = 5;
 204
 205         i = unlink(sockpath);
 206         if ((i != 0) && (errno != ENOENT)) {
 207                 syslog(LOG_ERR, "udsserver: %m");
 208                 return(-1);
 209         }
 210
 211         memset(&addr, 0, sizeof(addr));
 212         addr.sun_family = AF_UNIX;
 213         safestrncpy(addr.sun_path, sockpath, sizeof addr.sun_path);
 214
 215         s = socket(AF_UNIX, SOCK_STREAM, 0);
 216         if (s < 0) {
 217                 syslog(LOG_ERR, "udsserver: socket: %m");
 218                 return(-1);
 219         }
 220
 221         if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 222                 syslog(LOG_ERR, "udsserver: bind: %m");
 223                 return(-1);
 224         }
 225
 226         // set to nonblock - we need this for some obscure situations
 227         if (fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
 228                 syslog(LOG_ERR, "udsserver: fcntl: %m");
 229                 close(s);
 230                 return(-1);
 231         }
 232
 233         if (listen(s, actual_queue_len) < 0) {
 234                 syslog(LOG_ERR, "udsserver: listen: %m");
 235                 return(-1);
 236         }
 237
 238 #ifdef HAVE_STRUCT_UCRED
 239         setsockopt(s, SOL_SOCKET, SO_PASSCRED, &passcred, sizeof(passcred));
 240 #endif
 241
 242         chmod(sockpath, S_ISGID|S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IWGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH);
 243         return(s);
 244 }
 245
 246
 247 // The following functions implement output buffering on operating systems which
 248 // support it (such as Linux and various BSD flavors).
 249 #ifndef HAVE_DARWIN
 250 #ifdef TCP_CORK
 251 #       define HAVE_TCP_BUFFERING
 252 #else
 253 #       ifdef TCP_NOPUSH
 254 #               define HAVE_TCP_BUFFERING
 255 #               define TCP_CORK TCP_NOPUSH
 256 #       endif
 257 #endif // TCP_CORK
 258 #endif // HAVE_DARWIN
 259
 260 static unsigned on = 1, off = 0;
 261
 262 void buffer_output(void) {
 263 #ifdef HAVE_TCP_BUFFERING
 264 #ifdef HAVE_OPENSSL
 265         if (!CC->redirect_ssl)
 266 #endif
 267                 setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
 268 #endif
 269 }
 270
 271 void unbuffer_output(void) {
 272 #ifdef HAVE_TCP_BUFFERING
 273 #ifdef HAVE_OPENSSL
 274         if (!CC->redirect_ssl)
 275 #endif
 276                 setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
 277 #endif
 278 }
 279
 280 void flush_output(void) {
 281 #ifdef HAVE_TCP_BUFFERING
 282         setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
 283         setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
 284 #endif
 285 }
 286
 287
 288 // close the client socket
 289 void client_close(void) {
 290         if (!CC) return;
 291         if (CC->client_socket <= 0) return;
 292         syslog(LOG_DEBUG, "sysdep: closing socket %d", CC->client_socket);
 293         close(CC->client_socket);
 294         CC->client_socket = -1 ;
 295 }
 296
 297
 298 // Send binary data to the client.
 299 int client_write(const char *buf, int nbytes) {
 300         int bytes_written = 0;
 301         int retval;
 302 #ifndef HAVE_TCP_BUFFERING
 303         int old_buffer_len = 0;
 304 #endif
 305         fd_set wset;
 306         CitContext *Ctx;
 307         int fdflags;
 308
 309         if (nbytes < 1) return(0);
 310
 311         Ctx = CC;
 312         if (Ctx->redirect_buffer != NULL) {
 313                 StrBufAppendBufPlain(Ctx->redirect_buffer, buf, nbytes, 0);
 314                 return 0;
 315         }
 316
 317 #ifdef HAVE_OPENSSL
 318         if (Ctx->redirect_ssl) {
 319                 client_write_ssl(buf, nbytes);
 320                 return 0;
 321         }
 322 #endif
 323         if (Ctx->client_socket == -1) return -1;
 324
 325         fdflags = fcntl(Ctx->client_socket, F_GETFL);
 326
 327         while ((bytes_written < nbytes) && (Ctx->client_socket != -1)){
 328                 if ((fdflags & O_NONBLOCK) == O_NONBLOCK) {
 329                         FD_ZERO(&wset);
 330                         FD_SET(Ctx->client_socket, &wset);
 331                         if (select(1, NULL, &wset, NULL, NULL) == -1) {
 332                                 if (errno == EINTR) {
 333                                         syslog(LOG_DEBUG, "sysdep: client_write(%d bytes) select() interrupted.", nbytes-bytes_written);
 334                                         if (server_shutting_down) {
 335                                                 CC->kill_me = KILLME_SELECT_INTERRUPTED;
 336                                                 return (-1);
 337                                         }
 338                                         else {
 339                                                 // can't trust fd's and stuff so we need to re-create them
 340                                                 continue;
 341                                         }
 342                                 }
 343                                 else {
 344                                         syslog(LOG_ERR, "sysdep: client_write(%d bytes) select failed: %m", nbytes - bytes_written);
 345                                         client_close();
 346                                         Ctx->kill_me = KILLME_SELECT_FAILED;
 347                                         return -1;
 348                                 }
 349                         }
 350                 }
 351
 352                 retval = write(Ctx->client_socket, &buf[bytes_written], nbytes - bytes_written);
 353                 if (retval < 1) {
 354                         syslog(LOG_ERR, "sysdep: client_write(%d bytes) failed: %m", nbytes - bytes_written);
 355                         client_close();
 356                         Ctx->kill_me = KILLME_WRITE_FAILED;
 357                         return -1;
 358                 }
 359                 bytes_written = bytes_written + retval;
 360         }
 361         return 0;
 362 }
 363
 364
 365 void cputbuf(const StrBuf *Buf) {
 366         client_write(ChrPtr(Buf), StrLength(Buf));
 367 }
 368
 369
 370 // Send formatted printable data to the client.
 371 // Implemented in terms of client_write() so it's technically not sysdep...
 372 void cprintf(const char *format, ...) {
 373         va_list arg_ptr;
 374         char buf[1024];
 375         int rc;
 376
 377         va_start(arg_ptr, format);
 378         rc = vsnprintf(buf, sizeof buf, format, arg_ptr);
 379         if (rc < 0) {
 380                 syslog(LOG_ERR,"Console output error occured. Format: %s",format);
 381         } else {
 382                 if (rc >= sizeof buf) {
 383                         // Output was truncated.
 384                         // Chop at the end of the buffer
 385                         buf[sizeof buf - 2] = '\n';
 386                         buf[sizeof buf - 1] = 0;
 387                 }
 388                 client_write(buf, strlen(buf));
 389         }
 390         va_end(arg_ptr);
 391 }
 392
 393
 394 // Read data from the client socket.
 395 //
 396 // sock         socket fd to read from
 397 // buf          buffer to read into
 398 // bytes        number of bytes to read
 399 // timeout      Number of seconds to wait before timing out
 400 //
 401 // Possible return values:
 402 //      1       Requested number of bytes has been read.
 403 //      0       Request timed out.
 404 //      -1      Connection is broken, or other error.
 405 int client_read_blob(StrBuf *Target, int bytes, int timeout) {
 406         const char *Error;
 407         int retval = 0;
 408
 409 #ifdef HAVE_OPENSSL
 410         if (CC->redirect_ssl) {
 411                 retval = client_read_sslblob(Target, bytes, timeout);
 412                 if (retval < 0) {
 413                         syslog(LOG_ERR, "sysdep: client_read_blob() failed");
 414                 }
 415         }
 416         else
 417 #endif
 418         {
 419                 retval = StrBufReadBLOBBuffered(Target,
 420                                                 CC->RecvBuf.Buf,
 421                                                 &CC->RecvBuf.ReadWritePointer,
 422                                                 &CC->client_socket,
 423                                                 1,
 424                                                 bytes,
 425                                                 O_TERM,
 426                                                 &Error
 427                 );
 428                 if (retval < 0) {
 429                         syslog(LOG_ERR, "sysdep: client_read_blob() failed: %s", Error);
 430                         client_close();
 431                         return retval;
 432                 }
 433         }
 434         return retval;
 435 }
 436
 437
 438 // to make client_read_random_blob() more efficient, increase buffer size.
 439 // just use in greeting function, else your buffer may be flushed
 440 void client_set_inbound_buf(long N) {
 441         FlushStrBuf(CC->RecvBuf.Buf);
 442         ReAdjustEmptyBuf(CC->RecvBuf.Buf, N * SIZ, N * SIZ);
 443 }
 444
 445
 446 int client_read_random_blob(StrBuf *Target, int timeout) {
 447         int rc;
 448
 449         rc =  client_read_blob(Target, 1, timeout);
 450         if (rc > 0) {
 451                 long len;
 452                 const char *pch;
 453
 454                 len = StrLength(CC->RecvBuf.Buf);
 455                 pch = ChrPtr(CC->RecvBuf.Buf);
 456
 457                 if (len > 0) {
 458                         if (CC->RecvBuf.ReadWritePointer != NULL) {
 459                                 len -= CC->RecvBuf.ReadWritePointer - pch;
 460                                 pch = CC->RecvBuf.ReadWritePointer;
 461                         }
 462                         StrBufAppendBufPlain(Target, pch, len, 0);
 463                         FlushStrBuf(CC->RecvBuf.Buf);
 464                         CC->RecvBuf.ReadWritePointer = NULL;
 465                         return StrLength(Target);
 466                 }
 467                 return rc;
 468         }
 469         else
 470                 return rc;
 471 }
 472
 473
 474 int client_read_to(char *buf, int bytes, int timeout) {
 475         int rc;
 476
 477         rc = client_read_blob(CC->MigrateBuf, bytes, timeout);
 478         if (rc < 0) {
 479                 *buf = '\0';
 480                 return rc;
 481         }
 482         else {
 483                 memcpy(buf,
 484                        ChrPtr(CC->MigrateBuf),
 485                        StrLength(CC->MigrateBuf) + 1);
 486                 FlushStrBuf(CC->MigrateBuf);
 487                 return rc;
 488         }
 489 }
 490
 491
 492 int HaveMoreLinesWaiting(CitContext *ctx) {
 493         if (    (ctx->kill_me != 0)
 494                 || ( (ctx->RecvBuf.ReadWritePointer == NULL)
 495                 && (StrLength(ctx->RecvBuf.Buf) == 0)
 496                 && (ctx->client_socket != -1))
 497         )
 498                 return 0;
 499         else
 500                 return 1;
 501 }
 502
 503
 504 // Read data from the client socket with default timeout.
 505 // (This is implemented in terms of client_read_to() and could be
 506 // justifiably moved out of sysdep.c)
 507 INLINE int client_read(char *buf, int bytes) {
 508         return(client_read_to(buf, bytes, CtdlGetConfigInt("c_sleeping")));
 509 }
 510
 511
 512 int CtdlClientGetLine(StrBuf *Target) {
 513         const char *Error;
 514         int rc;
 515
 516         FlushStrBuf(Target);
 517 #ifdef HAVE_OPENSSL
 518         if (CC->redirect_ssl) {
 519                 rc = client_readline_sslbuffer(Target, CC->RecvBuf.Buf, &CC->RecvBuf.ReadWritePointer, 1);
 520                 return rc;
 521         }
 522         else
 523 #endif
 524         {
 525                 rc = StrBufTCP_read_buffered_line_fast(Target,
 526                                                        CC->RecvBuf.Buf,
 527                                                        &CC->RecvBuf.ReadWritePointer,
 528                                                        &CC->client_socket,
 529                                                        5,
 530                                                        1,
 531                                                        &Error
 532                 );
 533                 return rc;
 534         }
 535 }
 536
 537
 538 // Get a LF-terminated line of text from the client.
 539 // (This is implemented in terms of client_read() and could be
 540 // justifiably moved out of sysdep.c)
 541 int client_getln(char *buf, int bufsize) {
 542         int i, retval;
 543         const char *pCh;
 544
 545         retval = CtdlClientGetLine(CC->MigrateBuf);
 546         if (retval < 0)
 547           return(retval >= 0);
 548
 549
 550         i = StrLength(CC->MigrateBuf);
 551         pCh = ChrPtr(CC->MigrateBuf);
 552         // Strip the trailing LF, and the trailing CR if present.
 553         if (bufsize <= i)
 554                 i = bufsize - 1;
 555         while ( (i > 0)
 556                 && ( (pCh[i - 1]==13)
 557                      || ( pCh[i - 1]==10)) ) {
 558                 i--;
 559         }
 560         memcpy(buf, pCh, i);
 561         buf[i] = 0;
 562
 563         FlushStrBuf(CC->MigrateBuf);
 564         if (retval < 0) {
 565                 safestrncpy(&buf[i], "000", bufsize - i);
 566         }
 567         return(retval >= 0);
 568 }
 569
 570
 571 // The system-dependent part of master_cleanup() - close the master socket.
 572 void sysdep_master_cleanup(void) {
 573         context_cleanup();
 574 }
 575
 576
 577
 578 pid_t current_child;
 579 void graceful_shutdown(int signum) {
 580         kill(current_child, signum);
 581         unlink(file_pid_file);
 582         exit(0);
 583 }
 584
 585 int nFireUps = 0;
 586 int nFireUpsNonRestart = 0;
 587 pid_t ForkedPid = 1;
 588
 589 // Start running as a daemon.
 590 void start_daemon(int unused) {
 591         int status = 0;
 592         pid_t child = 0;
 593         FILE *fp;
 594         int do_restart = 0;
 595         current_child = 0;
 596
 597         // Close stdin/stdout/stderr and replace them with /dev/null.
 598         // We don't just call close() because we don't want these fd's
 599         // to be reused for other files.
 600         child = fork();
 601         if (child != 0) {
 602                 exit(0);
 603         }
 604
 605         signal(SIGHUP, SIG_IGN);
 606         signal(SIGINT, SIG_IGN);
 607         signal(SIGQUIT, SIG_IGN);
 608
 609         setsid();
 610         umask(0);
 611         if (    (freopen("/dev/null", "r", stdin) != stdin) ||
 612                 (freopen("/dev/null", "w", stdout) != stdout) ||
 613                 (freopen("/dev/null", "w", stderr) != stderr)
 614         ) {
 615                 syslog(LOG_ERR, "sysdep: unable to reopen stdio: %m");
 616         }
 617
 618         do {
 619                 current_child = fork();
 620                 signal(SIGTERM, graceful_shutdown);
 621                 if (current_child < 0) {
 622                         perror("fork");
 623                         exit(errno);
 624                 }
 625                 else if (current_child == 0) {
 626                         return; // continue starting citadel.
 627                 }
 628                 else {
 629                         fp = fopen(file_pid_file, "w");
 630                         if (fp != NULL) {
 631                                 fprintf(fp, ""F_PID_T"\n", getpid());
 632                                 fclose(fp);
 633                         }
 634                         waitpid(current_child, &status, 0);
 635                 }
 636                 nFireUpsNonRestart = nFireUps;
 637
 638                 // Exit code 0 means the watcher should exit
 639                 if (WIFEXITED(status) && (WEXITSTATUS(status) == CTDLEXIT_SHUTDOWN)) {
 640                         do_restart = 0;
 641                 }
 642
 643                 // Exit code 101-109 means the watcher should exit
 644                 else if (WIFEXITED(status) && (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109)) {
 645                         do_restart = 0;
 646                 }
 647
 648                 // Any other exit code, or no exit code, means we should restart.
 649                 else {
 650                         do_restart = 1;
 651                         nFireUps++;
 652                         ForkedPid = current_child;
 653                 }
 654
 655         } while (do_restart);
 656
 657         unlink(file_pid_file);
 658         exit(WEXITSTATUS(status));
 659 }
 660
 661
 662 void checkcrash(void) {
 663         if (nFireUpsNonRestart != nFireUps) {
 664                 StrBuf *CrashMail;
 665                 CrashMail = NewStrBuf();
 666                 syslog(LOG_ALERT, "sysdep: posting crash message");
 667                 StrBufPrintf(CrashMail,
 668                         " \n"
 669                         " The Citadel server process (citserver) terminated unexpectedly."
 670                         "\n \n"
 671                         " This could be the result of a bug in the server program, or some external "
 672                         "factor.\n \n"
 673                         " You can obtain more information about this by enabling core dumps.\n \n"
 674                         " For more information, please see:\n \n"
 675                         " http://citadel.org/doku.php?id=faq:mastering_your_os:gdb#how.do.i.make.my.system.produce.core-files"
 676                         "\n \n"
 677
 678                         " If you have already done this, the core dump is likely to be found at %score.%d\n"
 679                         ,
 680                         ctdl_run_dir, ForkedPid);
 681                 CtdlAideMessage(ChrPtr(CrashMail), "Citadel server process terminated unexpectedly");
 682                 FreeStrBuf(&CrashMail);
 683         }
 684 }
 685
 686
 687 // Generic routine to convert a login name to a full name (gecos)
 688 // Returns nonzero if a conversion took place
 689 int convert_login(char NameToConvert[]) {
 690         struct passwd *pw;
 691         unsigned int a;
 692
 693         pw = getpwnam(NameToConvert);
 694         if (pw == NULL) {
 695                 return(0);
 696         }
 697         else {
 698                 strcpy(NameToConvert, pw->pw_gecos);
 699                 for (a=0; a<strlen(NameToConvert); ++a) {
 700                         if (NameToConvert[a] == ',') NameToConvert[a] = 0;
 701                 }
 702                 return(1);
 703         }
 704 }
 705
 706
 707 void HuntBadSession(void) {
 708         int highest;
 709         CitContext *ptr;
 710         fd_set readfds;
 711         struct timeval tv;
 712         struct ServiceFunctionHook *serviceptr;
 713
 714         // Next, add all of the client sockets
 715         begin_critical_section(S_SESSION_TABLE);
 716         for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 717                 if ((ptr->state == CON_SYS) && (ptr->client_socket == 0))
 718                         continue;
 719                 // Initialize the fdset.
 720                 FD_ZERO(&readfds);
 721                 highest = 0;
 722                 tv.tv_sec = 0;          // wake up every second if no input
 723                 tv.tv_usec = 0;
 724
 725                 // Don't select on dead sessions, only truly idle ones
 726                 if (    (ptr->state == CON_IDLE)
 727                         && (ptr->kill_me == 0)
 728                         && (ptr->client_socket > 0)
 729                 ) {
 730                         FD_SET(ptr->client_socket, &readfds);
 731                         if (ptr->client_socket > highest)
 732                                 highest = ptr->client_socket;
 733
 734                         if ((select(highest + 1, &readfds, NULL, NULL, &tv) < 0) && (errno == EBADF)) {
 735                                 // Gotcha!
 736                                 syslog(LOG_ERR,
 737                                        "sysdep: killing session CC[%d] bad FD: [%d] User[%s] Host[%s:%s]",
 738                                         ptr->cs_pid,
 739                                         ptr->client_socket,
 740                                         ptr->curr_user,
 741                                         ptr->cs_host,
 742                                         ptr->cs_addr
 743                                 );
 744                                 ptr->kill_me = 1;
 745                                 ptr->client_socket = -1;
 746                                 break;
 747                         }
 748                 }
 749         }
 750         end_critical_section(S_SESSION_TABLE);
 751
 752         // First, add the various master sockets to the fdset.
 753         for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next ) {
 754
 755                 // Initialize the fdset.
 756                 highest = 0;
 757                 tv.tv_sec = 0;          // wake up every second if no input
 758                 tv.tv_usec = 0;
 759
 760                 FD_SET(serviceptr->msock, &readfds);
 761                 if (serviceptr->msock > highest) {
 762                         highest = serviceptr->msock;
 763                 }
 764                 if ((select(highest + 1, &readfds, NULL, NULL, &tv) < 0) && (errno == EBADF)) {
 765                         // Gotcha! server socket dead? commit suicide!
 766                         syslog(LOG_ERR, "sysdep: found bad FD: %d and its a server socket! Shutting Down!", serviceptr->msock);
 767                         server_shutting_down = 1;
 768                         break;
 769                 }
 770         }
 771 }
 772
 773
 774 // Main server loop
 775 // select() can wake up on any of the following conditions:
 776 // 1. A new client connection on a master socket
 777 // 2. Received data on a client socket
 778 // 3. A timer event
 779 // That's why we are blocking on select() and not accept().
 780 void *worker_thread(void *blah) {
 781         int highest;
 782         CitContext *ptr;
 783         CitContext *bind_me = NULL;
 784         fd_set readfds;
 785         int retval = 0;
 786         struct timeval tv;
 787         int force_purge = 0;
 788         struct ServiceFunctionHook *serviceptr;
 789         int ssock;                      // Descriptor for client socket
 790         CitContext *con = NULL;         // Temporary context pointer
 791         int i;
 792
 793         pthread_mutex_lock(&ThreadCountMutex);
 794         ++num_workers;
 795         pthread_mutex_unlock(&ThreadCountMutex);
 796
 797         while (!server_shutting_down) {
 798
 799                 // make doubly sure we're not holding any stale db handles which might cause a deadlock
 800                 cdb_check_handles();
 801 do_select:      force_purge = 0;
 802                 bind_me = NULL;         // Which session shall we handle?
 803
 804                 // Initialize the fdset
 805                 FD_ZERO(&readfds);
 806                 highest = 0;
 807
 808                 // First, add the various master sockets to the fdset.
 809                 for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next ) {
 810                         FD_SET(serviceptr->msock, &readfds);
 811                         if (serviceptr->msock > highest) {
 812                                 highest = serviceptr->msock;
 813                         }
 814                 }
 815
 816                 // Next, add all of the client sockets.
 817                 begin_critical_section(S_SESSION_TABLE);
 818                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 819                         if ((ptr->state == CON_SYS) && (ptr->client_socket == 0))
 820                             continue;
 821
 822                         // Don't select on dead sessions, only truly idle ones
 823                         if (    (ptr->state == CON_IDLE)
 824                                 && (ptr->kill_me == 0)
 825                                 && (ptr->client_socket > 0)
 826                         ) {
 827                                 FD_SET(ptr->client_socket, &readfds);
 828                                 if (ptr->client_socket > highest)
 829                                         highest = ptr->client_socket;
 830                         }
 831                         if ((bind_me == NULL) && (ptr->state == CON_READY)) {
 832                                 bind_me = ptr;
 833                                 ptr->state = CON_EXECUTING;
 834                                 break;
 835                         }
 836                         if ((bind_me == NULL) && (ptr->state == CON_GREETING)) {
 837                                 bind_me = ptr;
 838                                 ptr->state = CON_STARTING;
 839                                 break;
 840                         }
 841                 }
 842                 end_critical_section(S_SESSION_TABLE);
 843
 844                 if (bind_me) {
 845                         goto SKIP_SELECT;
 846                 }
 847
 848                 // If we got this far, it means that there are no sessions
 849                 // which a previous thread marked for attention, so we go
 850                 // ahead and get ready to select().
 851
 852                 if (!server_shutting_down) {
 853                         tv.tv_sec = 1;          // wake up every second if no input
 854                         tv.tv_usec = 0;
 855                         retval = select(highest + 1, &readfds, NULL, NULL, &tv);
 856                 }
 857                 else {
 858                         --num_workers;
 859                         return NULL;
 860                 }
 861
 862                 // Now figure out who made this select() unblock.
 863                 // First, check for an error or exit condition.
 864                 if (retval < 0) {
 865                         if (errno == EBADF) {
 866                                 syslog(LOG_ERR, "sysdep: select() failed: %m");
 867                                 HuntBadSession();
 868                                 goto do_select;
 869                         }
 870                         if (errno != EINTR) {
 871                                 syslog(LOG_ERR, "sysdep: exiting: %m");
 872                                 server_shutting_down = 1;
 873                                 continue;
 874                         } else {
 875                                 if (server_shutting_down) {
 876                                         --num_workers;
 877                                         return(NULL);
 878                                 }
 879                                 goto do_select;
 880                         }
 881                 }
 882                 else if (retval == 0) {
 883                         if (server_shutting_down) {
 884                                 --num_workers;
 885                                 return(NULL);
 886                         }
 887                 }
 888
 889                 // Next, check to see if it's a new client connecting on a master socket.
 890
 891                 else if ((retval > 0) && (!server_shutting_down)) for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next) {
 892
 893                         if (FD_ISSET(serviceptr->msock, &readfds)) {
 894                                 ssock = accept(serviceptr->msock, NULL, 0);
 895                                 if (ssock >= 0) {
 896                                         syslog(LOG_DEBUG, "sysdep: new client socket %d", ssock);
 897
 898                                         // The master socket is non-blocking but the client
 899                                         // sockets need to be blocking, otherwise certain
 900                                         // operations barf on FreeBSD.  Not a fatal error.
 901                                         if (fcntl(ssock, F_SETFL, 0) < 0) {
 902                                                 syslog(LOG_ERR, "sysdep: Can't set socket to blocking: %m");
 903                                         }
 904
 905                                         // New context will be created already
 906                                         // set up in the CON_EXECUTING state.
 907                                         con = CreateNewContext();
 908
 909                                         // Assign our new socket number to it.
 910                                         con->tcp_port = serviceptr->tcp_port;
 911                                         con->client_socket = ssock;
 912                                         con->h_command_function = serviceptr->h_command_function;
 913                                         con->h_async_function = serviceptr->h_async_function;
 914                                         con->h_greeting_function = serviceptr->h_greeting_function;
 915                                         con->ServiceName = serviceptr->ServiceName;
 916
 917                                         // Connections on a local client are always from the same host
 918                                         if (serviceptr->sockpath != NULL) {
 919                                                 con->is_local_client = 1;
 920                                         }
 921
 922                                         // Set the SO_REUSEADDR socket option
 923                                         i = 1;
 924                                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 925                                         con->state = CON_GREETING;
 926                                         retval--;
 927                                         if (retval == 0)
 928                                                 break;
 929                                 }
 930                         }
 931                 }
 932
 933                 // It must be a client socket.  Find a context that has data
 934                 // waiting on its socket *and* is in the CON_IDLE state.  Any
 935                 // active sockets other than our chosen one are marked as
 936                 // CON_READY so the next thread that comes around can just bind
 937                 // to one without having to select() again.
 938                 begin_critical_section(S_SESSION_TABLE);
 939                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 940                         int checkfd = ptr->client_socket;
 941                         if ((checkfd != -1) && (ptr->state == CON_IDLE) ){
 942                                 if (FD_ISSET(checkfd, &readfds)) {
 943                                         ptr->input_waiting = 1;
 944                                         if (!bind_me) {
 945                                                 bind_me = ptr;  // I choose you!
 946                                                 bind_me->state = CON_EXECUTING;
 947                                         }
 948                                         else {
 949                                                 ptr->state = CON_READY;
 950                                         }
 951                                 } else if ((ptr->is_async) && (ptr->async_waiting) && (ptr->h_async_function)) {
 952                                         if (!bind_me) {
 953                                                 bind_me = ptr;  // I choose you!
 954                                                 bind_me->state = CON_EXECUTING;
 955                                         }
 956                                         else {
 957                                                 ptr->state = CON_READY;
 958                                         }
 959                                 }
 960                         }
 961                 }
 962                 end_critical_section(S_SESSION_TABLE);
 963
 964 SKIP_SELECT:
 965                 // We're bound to a session
 966                 pthread_mutex_lock(&ThreadCountMutex);
 967                 ++active_workers;
 968                 pthread_mutex_unlock(&ThreadCountMutex);
 969
 970                 if (bind_me != NULL) {
 971                         become_session(bind_me);
 972
 973                         if (bind_me->state == CON_STARTING) {
 974                                 bind_me->state = CON_EXECUTING;
 975                                 begin_session(bind_me);
 976                                 bind_me->h_greeting_function();
 977                         }
 978                         // If the client has sent a command, execute it.
 979                         if (CC->input_waiting) {
 980                                 CC->h_command_function();
 981
 982                                 while (HaveMoreLinesWaiting(CC))
 983                                        CC->h_command_function();
 984
 985                                 CC->input_waiting = 0;
 986                         }
 987
 988                         // If there are asynchronous messages waiting and the client supports it, do those now
 989                         if ((CC->is_async) && (CC->async_waiting) && (CC->h_async_function != NULL)) {
 990                                 CC->h_async_function();
 991                                 CC->async_waiting = 0;
 992                         }
 993
 994                         force_purge = CC->kill_me;
 995                         become_session(NULL);
 996                         bind_me->state = CON_IDLE;
 997                 }
 998
 999                 dead_session_purge(force_purge);
1000                 do_housekeeping();
1001
1002                 pthread_mutex_lock(&ThreadCountMutex);
1003                 --active_workers;
1004                 if ((active_workers + CtdlGetConfigInt("c_min_workers") < num_workers) &&
1005                     (num_workers > CtdlGetConfigInt("c_min_workers")))
1006                 {
1007                         num_workers--;
1008                         pthread_mutex_unlock(&ThreadCountMutex);
1009                         return (NULL);
1010                 }
1011                 pthread_mutex_unlock(&ThreadCountMutex);
1012         }
1013
1014         // If control reaches this point, the server is shutting down
1015         pthread_mutex_lock(&ThreadCountMutex);
1016         --num_workers;
1017         pthread_mutex_unlock(&ThreadCountMutex);
1018         return(NULL);
1019 }
1020
1021
1022 // SyslogFacility()
1023 // Translate text facility name to syslog.h defined value.
1024 int SyslogFacility(char *name)
1025 {
1026         int i;
1027         struct
1028         {
1029                 int facility;
1030                 char *name;
1031         }   facTbl[] =
1032         {
1033                 {   LOG_KERN,   "kern"          },
1034                 {   LOG_USER,   "user"          },
1035                 {   LOG_MAIL,   "mail"          },
1036                 {   LOG_DAEMON, "daemon"        },
1037                 {   LOG_AUTH,   "auth"          },
1038                 {   LOG_SYSLOG, "syslog"        },
1039                 {   LOG_LPR,    "lpr"           },
1040                 {   LOG_NEWS,   "news"          },
1041                 {   LOG_UUCP,   "uucp"          },
1042                 {   LOG_LOCAL0, "local0"        },
1043                 {   LOG_LOCAL1, "local1"        },
1044                 {   LOG_LOCAL2, "local2"        },
1045                 {   LOG_LOCAL3, "local3"        },
1046                 {   LOG_LOCAL4, "local4"        },
1047                 {   LOG_LOCAL5, "local5"        },
1048                 {   LOG_LOCAL6, "local6"        },
1049                 {   LOG_LOCAL7, "local7"        },
1050                 {   0,            NULL          }
1051         };
1052         for(i = 0; facTbl[i].name != NULL; i++) {
1053                 if(!strcasecmp(name, facTbl[i].name))
1054                         return facTbl[i].facility;
1055         }
1056         return LOG_DAEMON;
1057 }