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