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) 1987-2022 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 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 #include "sysdep.h"
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19 #include <sys/stat.h>
  20 #include <errno.h>
  21 #include <signal.h>
  22 #include <stdio.h>
  23 #include <syslog.h>
  24 #include <sys/syslog.h>
  25 #include <execinfo.h>
  26 #include <netdb.h>
  27 #include <sys/un.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <netinet/tcp.h>
  33 #include <arpa/inet.h>
  34 #define SHOW_ME_VAPPEND_PRINTF
  35 #include <libcitadel.h>
  36 #include "citserver.h"
  37 #include "config.h"
  38 #include "ctdl_module.h"
  39 #include "sysdep_decls.h"
  40 #include "modules/crypto/serv_crypto.h" // Needed for init_ssl, client_write_ssl, client_read_ssl
  41 #include "housekeeping.h"
  42 #include "context.h"
  43
  44 // Signal handler to shut down the server.
  45 volatile int exit_signal = 0;
  46 volatile int shutdown_and_halt = 0;
  47 volatile int restart_server = 0;
  48 volatile int running_as_daemon = 0;
  49
  50
  51 static RETSIGTYPE signal_cleanup(int signum) {
  52         syslog(LOG_DEBUG, "sysdep: caught signal %d", signum);
  53         exit_signal = signum;
  54         server_shutting_down = 1;
  55 }
  56
  57
  58 // Some initialization stuff...
  59 void init_sysdep(void) {
  60         sigset_t set;
  61
  62         // Avoid vulnerabilities related to FD_SETSIZE if we can.
  63 #ifdef FD_SETSIZE
  64 #ifdef RLIMIT_NOFILE
  65         struct rlimit rl;
  66         getrlimit(RLIMIT_NOFILE, &rl);
  67         rl.rlim_cur = FD_SETSIZE;
  68         rl.rlim_max = FD_SETSIZE;
  69         setrlimit(RLIMIT_NOFILE, &rl);
  70 #endif
  71 #endif
  72
  73         // If we've got OpenSSL, we're going to use it.
  74 #ifdef HAVE_OPENSSL
  75         init_ssl();
  76 #endif
  77
  78         if (pthread_key_create(&ThreadKey, NULL) != 0) {                        // TSD for threads
  79                 syslog(LOG_ERR, "pthread_key_create() : %m");
  80                 abort();
  81         }
  82
  83         if (pthread_key_create(&MyConKey, NULL) != 0) {                         // TSD for sessions
  84                 syslog(LOG_CRIT, "sysdep: can't create TSD key: %m");
  85                 abort();
  86         }
  87
  88         // Interript, hangup, and terminate signals should cause the server to shut down.
  89         sigemptyset(&set);
  90         sigaddset(&set, SIGINT);
  91         sigaddset(&set, SIGHUP);
  92         sigaddset(&set, SIGTERM);
  93         sigprocmask(SIG_UNBLOCK, &set, NULL);
  94
  95         signal(SIGINT, signal_cleanup);
  96         signal(SIGHUP, signal_cleanup);
  97         signal(SIGTERM, signal_cleanup);
  98
  99         // Do not shut down the server on broken pipe signals, otherwise the
 100         // whole Citadel service would come down whenever a single client
 101         // socket breaks.
 102         signal(SIGPIPE, SIG_IGN);
 103 }
 104
 105
 106 // This is a generic function to set up a master socket for listening on
 107 // a TCP port.  The server shuts down if the bind fails.  (IPv4/IPv6 version)
 108 //
 109 // ip_addr      IP address to bind
 110 // port_number  port number to bind
 111 // queue_len    number of incoming connections to allow in the queue
 112 int ctdl_tcp_server(char *ip_addr, int port_number, int queue_len) {
 113         struct protoent *p;
 114         struct sockaddr_in6 sin6;
 115         struct sockaddr_in sin4;
 116         int s, i, b;
 117         int ip_version = 6;
 118
 119         memset(&sin6, 0, sizeof(sin6));
 120         memset(&sin4, 0, sizeof(sin4));
 121         sin6.sin6_family = AF_INET6;
 122         sin4.sin_family = AF_INET;
 123
 124         if (    (ip_addr == NULL)                                                       // any IPv6
 125                 || (IsEmptyStr(ip_addr))
 126                 || (!strcmp(ip_addr, "*"))
 127         ) {
 128                 ip_version = 6;
 129                 sin6.sin6_addr = in6addr_any;
 130         }
 131         else if (!strcmp(ip_addr, "0.0.0.0")) {                                         // any IPv4
 132                 ip_version = 4;
 133                 sin4.sin_addr.s_addr = INADDR_ANY;
 134         }
 135         else if ((strchr(ip_addr, '.')) && (!strchr(ip_addr, ':'))) {                   // specific IPv4
 136                 ip_version = 4;
 137                 if (inet_pton(AF_INET, ip_addr, &sin4.sin_addr) <= 0) {
 138                         syslog(LOG_ALERT, "tcpserver: inet_pton: %m");
 139                         return (-1);
 140                 }
 141         }
 142         else {                                                                          // specific IPv6
 143                 ip_version = 6;
 144                 if (inet_pton(AF_INET6, ip_addr, &sin6.sin6_addr) <= 0) {
 145                         syslog(LOG_ALERT, "tcpserver: inet_pton: %m");
 146                         return (-1);
 147                 }
 148         }
 149
 150         if (port_number == 0) {
 151                 syslog(LOG_ALERT, "tcpserver: no port number was specified");
 152                 return (-1);
 153         }
 154         sin6.sin6_port = htons((u_short) port_number);
 155         sin4.sin_port = htons((u_short) port_number);
 156
 157         p = getprotobyname("tcp");
 158         if (p == NULL) {
 159                 syslog(LOG_ALERT, "tcpserver: getprotobyname: %m");
 160                 return (-1);
 161         }
 162
 163         s = socket( ((ip_version == 6) ? PF_INET6 : PF_INET), SOCK_STREAM, (p->p_proto));
 164         if (s < 0) {
 165                 syslog(LOG_ALERT, "tcpserver: socket: %m");
 166                 return (-1);
 167         }
 168         // Set some socket options that make sense.
 169         i = 1;
 170         setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 171
 172         if (ip_version == 6) {
 173                 b = bind(s, (struct sockaddr *) &sin6, sizeof(sin6));
 174         }
 175         else {
 176                 b = bind(s, (struct sockaddr *) &sin4, sizeof(sin4));
 177         }
 178
 179         if (b < 0) {
 180                 syslog(LOG_ALERT, "tcpserver: bind: %m");
 181                 return (-1);
 182         }
 183
 184         fcntl(s, F_SETFL, O_NONBLOCK);
 185
 186         if (listen(s, ((queue_len >= 5) ? queue_len : 5) ) < 0) {
 187                 syslog(LOG_ALERT, "tcpserver: listen: %m");
 188                 return (-1);
 189         }
 190         return (s);
 191 }
 192
 193
 194 // Create a Unix domain socket and listen on it
 195 int ctdl_uds_server(char *sockpath, int queue_len) {
 196         struct sockaddr_un addr;
 197         int s;
 198         int i;
 199         int actual_queue_len;
 200 #ifdef HAVE_STRUCT_UCRED
 201         int passcred = 1;
 202 #endif
 203
 204         actual_queue_len = queue_len;
 205         if (actual_queue_len < 5) actual_queue_len = 5;
 206
 207         i = unlink(sockpath);
 208         if ((i != 0) && (errno != ENOENT)) {
 209                 syslog(LOG_ERR, "udsserver: %m");
 210                 return(-1);
 211         }
 212
 213         memset(&addr, 0, sizeof(addr));
 214         addr.sun_family = AF_UNIX;
 215         safestrncpy(addr.sun_path, sockpath, sizeof addr.sun_path);
 216
 217         s = socket(AF_UNIX, SOCK_STREAM, 0);
 218         if (s < 0) {
 219                 syslog(LOG_ERR, "udsserver: socket: %m");
 220                 return(-1);
 221         }
 222
 223         if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 224                 syslog(LOG_ERR, "udsserver: bind: %m");
 225                 return(-1);
 226         }
 227
 228         // set to nonblock - we need this for some obscure situations
 229         if (fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
 230                 syslog(LOG_ERR, "udsserver: fcntl: %m");
 231                 close(s);
 232                 return(-1);
 233         }
 234
 235         if (listen(s, actual_queue_len) < 0) {
 236                 syslog(LOG_ERR, "udsserver: listen: %m");
 237                 return(-1);
 238         }
 239
 240 #ifdef HAVE_STRUCT_UCRED
 241         setsockopt(s, SOL_SOCKET, SO_PASSCRED, &passcred, sizeof(passcred));
 242 #endif
 243
 244         chmod(sockpath, S_ISGID|S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IWGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH);
 245         return(s);
 246 }
 247
 248
 249 // The following functions implement output buffering on operating systems which
 250 // support it (such as Linux and various BSD flavors).
 251 #ifndef HAVE_DARWIN
 252 #ifdef TCP_CORK
 253 #       define HAVE_TCP_BUFFERING
 254 #else
 255 #       ifdef TCP_NOPUSH
 256 #               define HAVE_TCP_BUFFERING
 257 #               define TCP_CORK TCP_NOPUSH
 258 #       endif
 259 #endif // TCP_CORK
 260 #endif // HAVE_DARWIN
 261
 262 static unsigned on = 1, off = 0;
 263
 264 void buffer_output(void) {
 265 #ifdef HAVE_TCP_BUFFERING
 266 #ifdef HAVE_OPENSSL
 267         if (!CC->redirect_ssl)
 268 #endif
 269                 setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
 270 #endif
 271 }
 272
 273 void unbuffer_output(void) {
 274 #ifdef HAVE_TCP_BUFFERING
 275 #ifdef HAVE_OPENSSL
 276         if (!CC->redirect_ssl)
 277 #endif
 278                 setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
 279 #endif
 280 }
 281
 282 void flush_output(void) {
 283 #ifdef HAVE_TCP_BUFFERING
 284         setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
 285         setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
 286 #endif
 287 }
 288
 289
 290 // close the client socket
 291 void client_close(void) {
 292         if (!CC) return;
 293         if (CC->client_socket <= 0) return;
 294         syslog(LOG_DEBUG, "sysdep: closing socket %d", CC->client_socket);
 295         close(CC->client_socket);
 296         CC->client_socket = -1 ;
 297 }
 298
 299
 300 // Send binary data to the client.
 301 int client_write(const char *buf, int nbytes) {
 302         int bytes_written = 0;
 303         int retval;
 304 #ifndef HAVE_TCP_BUFFERING
 305         int old_buffer_len = 0;
 306 #endif
 307         fd_set wset;
 308         CitContext *Ctx;
 309         int fdflags;
 310
 311         if (nbytes < 1) return(0);
 312
 313         Ctx = CC;
 314         if (Ctx->redirect_buffer != NULL) {
 315                 StrBufAppendBufPlain(Ctx->redirect_buffer, buf, nbytes, 0);
 316                 return 0;
 317         }
 318
 319 #ifdef HAVE_OPENSSL
 320         if (Ctx->redirect_ssl) {
 321                 client_write_ssl(buf, nbytes);
 322                 return 0;
 323         }
 324 #endif
 325         if (Ctx->client_socket == -1) return -1;
 326
 327         fdflags = fcntl(Ctx->client_socket, F_GETFL);
 328
 329         while ((bytes_written < nbytes) && (Ctx->client_socket != -1)){
 330                 if ((fdflags & O_NONBLOCK) == O_NONBLOCK) {
 331                         FD_ZERO(&wset);
 332                         FD_SET(Ctx->client_socket, &wset);
 333                         if (select(1, NULL, &wset, NULL, NULL) == -1) {
 334                                 if (errno == EINTR) {
 335                                         syslog(LOG_DEBUG, "sysdep: client_write(%d bytes) select() interrupted.", nbytes-bytes_written);
 336                                         if (server_shutting_down) {
 337                                                 CC->kill_me = KILLME_SELECT_INTERRUPTED;
 338                                                 return (-1);
 339                                         }
 340                                         else {
 341                                                 // can't trust fd's and stuff so we need to re-create them
 342                                                 continue;
 343                                         }
 344                                 }
 345                                 else {
 346                                         syslog(LOG_ERR, "sysdep: client_write(%d bytes) select failed: %m", nbytes - bytes_written);
 347                                         client_close();
 348                                         Ctx->kill_me = KILLME_SELECT_FAILED;
 349                                         return -1;
 350                                 }
 351                         }
 352                 }
 353
 354                 retval = write(Ctx->client_socket, &buf[bytes_written], nbytes - bytes_written);
 355                 if (retval < 1) {
 356                         syslog(LOG_ERR, "sysdep: client_write(%d bytes) failed: %m", nbytes - bytes_written);
 357                         client_close();
 358                         Ctx->kill_me = KILLME_WRITE_FAILED;
 359                         return -1;
 360                 }
 361                 bytes_written = bytes_written + retval;
 362         }
 363         return 0;
 364 }
 365
 366
 367 void cputbuf(const StrBuf *Buf) {
 368         client_write(ChrPtr(Buf), StrLength(Buf));
 369 }
 370
 371
 372 // Send formatted printable data to the client.
 373 // Implemented in terms of client_write() so it's technically not sysdep...
 374 void cprintf(const char *format, ...) {
 375         va_list arg_ptr;
 376         char buf[1024];
 377
 378         va_start(arg_ptr, format);
 379         if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
 380                 buf[sizeof buf - 2] = '\n';
 381         client_write(buf, strlen(buf));
 382         va_end(arg_ptr);
 383 }
 384
 385
 386 // Read data from the client socket.
 387 //
 388 // sock         socket fd to read from
 389 // buf          buffer to read into
 390 // bytes        number of bytes to read
 391 // timeout      Number of seconds to wait before timing out
 392 //
 393 // Possible return values:
 394 //      1       Requested number of bytes has been read.
 395 //      0       Request timed out.
 396 //      -1      Connection is broken, or other error.
 397 int client_read_blob(StrBuf *Target, int bytes, int timeout) {
 398         const char *Error;
 399         int retval = 0;
 400
 401 #ifdef HAVE_OPENSSL
 402         if (CC->redirect_ssl) {
 403                 retval = client_read_sslblob(Target, bytes, timeout);
 404                 if (retval < 0) {
 405                         syslog(LOG_ERR, "sysdep: client_read_blob() failed");
 406                 }
 407         }
 408         else
 409 #endif
 410         {
 411                 retval = StrBufReadBLOBBuffered(Target,
 412                                                 CC->RecvBuf.Buf,
 413                                                 &CC->RecvBuf.ReadWritePointer,
 414                                                 &CC->client_socket,
 415                                                 1,
 416                                                 bytes,
 417                                                 O_TERM,
 418                                                 &Error
 419                 );
 420                 if (retval < 0) {
 421                         syslog(LOG_ERR, "sysdep: client_read_blob() failed: %s", Error);
 422                         client_close();
 423                         return retval;
 424                 }
 425         }
 426         return retval;
 427 }
 428
 429
 430 // to make client_read_random_blob() more efficient, increase buffer size.
 431 // just use in greeting function, else your buffer may be flushed
 432 void client_set_inbound_buf(long N) {
 433         FlushStrBuf(CC->RecvBuf.Buf);
 434         ReAdjustEmptyBuf(CC->RecvBuf.Buf, N * SIZ, N * SIZ);
 435 }
 436
 437
 438 int client_read_random_blob(StrBuf *Target, int timeout) {
 439         int rc;
 440
 441         rc =  client_read_blob(Target, 1, timeout);
 442         if (rc > 0) {
 443                 long len;
 444                 const char *pch;
 445
 446                 len = StrLength(CC->RecvBuf.Buf);
 447                 pch = ChrPtr(CC->RecvBuf.Buf);
 448
 449                 if (len > 0) {
 450                         if (CC->RecvBuf.ReadWritePointer != NULL) {
 451                                 len -= CC->RecvBuf.ReadWritePointer - pch;
 452                                 pch = CC->RecvBuf.ReadWritePointer;
 453                         }
 454                         StrBufAppendBufPlain(Target, pch, len, 0);
 455                         FlushStrBuf(CC->RecvBuf.Buf);
 456                         CC->RecvBuf.ReadWritePointer = NULL;
 457                         return StrLength(Target);
 458                 }
 459                 return rc;
 460         }
 461         else
 462                 return rc;
 463 }
 464
 465
 466 int client_read_to(char *buf, int bytes, int timeout) {
 467         int rc;
 468
 469         rc = client_read_blob(CC->MigrateBuf, bytes, timeout);
 470         if (rc < 0) {
 471                 *buf = '\0';
 472                 return rc;
 473         }
 474         else {
 475                 memcpy(buf,
 476                        ChrPtr(CC->MigrateBuf),
 477                        StrLength(CC->MigrateBuf) + 1);
 478                 FlushStrBuf(CC->MigrateBuf);
 479                 return rc;
 480         }
 481 }
 482
 483
 484 int HaveMoreLinesWaiting(CitContext *ctx) {
 485         if (    (ctx->kill_me != 0)
 486                 || ( (ctx->RecvBuf.ReadWritePointer == NULL)
 487                 && (StrLength(ctx->RecvBuf.Buf) == 0)
 488                 && (ctx->client_socket != -1))
 489         )
 490                 return 0;
 491         else
 492                 return 1;
 493 }
 494
 495
 496 // Read data from the client socket with default timeout.
 497 // (This is implemented in terms of client_read_to() and could be
 498 // justifiably moved out of sysdep.c)
 499 INLINE int client_read(char *buf, int bytes) {
 500         return(client_read_to(buf, bytes, CtdlGetConfigInt("c_sleeping")));
 501 }
 502
 503
 504 int CtdlClientGetLine(StrBuf *Target) {
 505         const char *Error;
 506         int rc;
 507
 508         FlushStrBuf(Target);
 509 #ifdef HAVE_OPENSSL
 510         if (CC->redirect_ssl) {
 511                 rc = client_readline_sslbuffer(Target, CC->RecvBuf.Buf, &CC->RecvBuf.ReadWritePointer, 1);
 512                 return rc;
 513         }
 514         else
 515 #endif
 516         {
 517                 rc = StrBufTCP_read_buffered_line_fast(Target,
 518                                                        CC->RecvBuf.Buf,
 519                                                        &CC->RecvBuf.ReadWritePointer,
 520                                                        &CC->client_socket,
 521                                                        5,
 522                                                        1,
 523                                                        &Error
 524                 );
 525                 return rc;
 526         }
 527 }
 528
 529
 530 // Get a LF-terminated line of text from the client.
 531 // (This is implemented in terms of client_read() and could be
 532 // justifiably moved out of sysdep.c)
 533 int client_getln(char *buf, int bufsize) {
 534         int i, retval;
 535         const char *pCh;
 536
 537         retval = CtdlClientGetLine(CC->MigrateBuf);
 538         if (retval < 0)
 539           return(retval >= 0);
 540
 541
 542         i = StrLength(CC->MigrateBuf);
 543         pCh = ChrPtr(CC->MigrateBuf);
 544         // Strip the trailing LF, and the trailing CR if present.
 545         if (bufsize <= i)
 546                 i = bufsize - 1;
 547         while ( (i > 0)
 548                 && ( (pCh[i - 1]==13)
 549                      || ( pCh[i - 1]==10)) ) {
 550                 i--;
 551         }
 552         memcpy(buf, pCh, i);
 553         buf[i] = 0;
 554
 555         FlushStrBuf(CC->MigrateBuf);
 556         if (retval < 0) {
 557                 safestrncpy(&buf[i], "000", bufsize - i);
 558         }
 559         return(retval >= 0);
 560 }
 561
 562
 563 // The system-dependent part of master_cleanup() - close the master socket.
 564 void sysdep_master_cleanup(void) {
 565         context_cleanup();
 566 }
 567
 568
 569
 570 pid_t current_child;
 571 void graceful_shutdown(int signum) {
 572         kill(current_child, signum);
 573         unlink(file_pid_file);
 574         exit(0);
 575 }
 576
 577 int nFireUps = 0;
 578 int nFireUpsNonRestart = 0;
 579 pid_t ForkedPid = 1;
 580
 581 // Start running as a daemon.
 582 void start_daemon(int unused) {
 583         int status = 0;
 584         pid_t child = 0;
 585         FILE *fp;
 586         int do_restart = 0;
 587         current_child = 0;
 588
 589         // Close stdin/stdout/stderr and replace them with /dev/null.
 590         // We don't just call close() because we don't want these fd's
 591         // to be reused for other files.
 592         child = fork();
 593         if (child != 0) {
 594                 exit(0);
 595         }
 596
 597         signal(SIGHUP, SIG_IGN);
 598         signal(SIGINT, SIG_IGN);
 599         signal(SIGQUIT, SIG_IGN);
 600
 601         setsid();
 602         umask(0);
 603         if (    (freopen("/dev/null", "r", stdin) != stdin) ||
 604                 (freopen("/dev/null", "w", stdout) != stdout) ||
 605                 (freopen("/dev/null", "w", stderr) != stderr)
 606         ) {
 607                 syslog(LOG_ERR, "sysdep: unable to reopen stdio: %m");
 608         }
 609
 610         do {
 611                 current_child = fork();
 612                 signal(SIGTERM, graceful_shutdown);
 613                 if (current_child < 0) {
 614                         perror("fork");
 615                         exit(errno);
 616                 }
 617                 else if (current_child == 0) {
 618                         return; // continue starting citadel.
 619                 }
 620                 else {
 621                         fp = fopen(file_pid_file, "w");
 622                         if (fp != NULL) {
 623                                 fprintf(fp, ""F_PID_T"\n", getpid());
 624                                 fclose(fp);
 625                         }
 626                         waitpid(current_child, &status, 0);
 627                 }
 628                 nFireUpsNonRestart = nFireUps;
 629
 630                 // Exit code 0 means the watcher should exit
 631                 if (WIFEXITED(status) && (WEXITSTATUS(status) == CTDLEXIT_SHUTDOWN)) {
 632                         do_restart = 0;
 633                 }
 634
 635                 // Exit code 101-109 means the watcher should exit
 636                 else if (WIFEXITED(status) && (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109)) {
 637                         do_restart = 0;
 638                 }
 639
 640                 // Any other exit code, or no exit code, means we should restart.
 641                 else {
 642                         do_restart = 1;
 643                         nFireUps++;
 644                         ForkedPid = current_child;
 645                 }
 646
 647         } while (do_restart);
 648
 649         unlink(file_pid_file);
 650         exit(WEXITSTATUS(status));
 651 }
 652
 653
 654 void checkcrash(void) {
 655         if (nFireUpsNonRestart != nFireUps) {
 656                 StrBuf *CrashMail;
 657                 CrashMail = NewStrBuf();
 658                 syslog(LOG_ALERT, "sysdep: posting crash message");
 659                 StrBufPrintf(CrashMail,
 660                         " \n"
 661                         " The Citadel server process (citserver) terminated unexpectedly."
 662                         "\n \n"
 663                         " This could be the result of a bug in the server program, or some external "
 664                         "factor.\n \n"
 665                         " You can obtain more information about this by enabling core dumps.\n \n"
 666                         " For more information, please see:\n \n"
 667                         " http://citadel.org/doku.php?id=faq:mastering_your_os:gdb#how.do.i.make.my.system.produce.core-files"
 668                         "\n \n"
 669
 670                         " If you have already done this, the core dump is likely to be found at %score.%d\n"
 671                         ,
 672                         ctdl_run_dir, ForkedPid);
 673                 CtdlAideMessage(ChrPtr(CrashMail), "Citadel server process terminated unexpectedly");
 674                 FreeStrBuf(&CrashMail);
 675         }
 676 }
 677
 678
 679 // Generic routine to convert a login name to a full name (gecos)
 680 // Returns nonzero if a conversion took place
 681 int convert_login(char NameToConvert[]) {
 682         struct passwd *pw;
 683         unsigned int a;
 684
 685         pw = getpwnam(NameToConvert);
 686         if (pw == NULL) {
 687                 return(0);
 688         }
 689         else {
 690                 strcpy(NameToConvert, pw->pw_gecos);
 691                 for (a=0; a<strlen(NameToConvert); ++a) {
 692                         if (NameToConvert[a] == ',') NameToConvert[a] = 0;
 693                 }
 694                 return(1);
 695         }
 696 }
 697
 698
 699 void HuntBadSession(void) {
 700         int highest;
 701         CitContext *ptr;
 702         fd_set readfds;
 703         struct timeval tv;
 704         struct ServiceFunctionHook *serviceptr;
 705
 706         // Next, add all of the client sockets
 707         begin_critical_section(S_SESSION_TABLE);
 708         for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 709                 if ((ptr->state == CON_SYS) && (ptr->client_socket == 0))
 710                         continue;
 711                 // Initialize the fdset.
 712                 FD_ZERO(&readfds);
 713                 highest = 0;
 714                 tv.tv_sec = 0;          // wake up every second if no input
 715                 tv.tv_usec = 0;
 716
 717                 // Don't select on dead sessions, only truly idle ones
 718                 if (    (ptr->state == CON_IDLE)
 719                         && (ptr->kill_me == 0)
 720                         && (ptr->client_socket > 0)
 721                 ) {
 722                         FD_SET(ptr->client_socket, &readfds);
 723                         if (ptr->client_socket > highest)
 724                                 highest = ptr->client_socket;
 725
 726                         if ((select(highest + 1, &readfds, NULL, NULL, &tv) < 0) && (errno == EBADF)) {
 727                                 // Gotcha!
 728                                 syslog(LOG_ERR,
 729                                        "sysdep: killing session CC[%d] bad FD: [%d] User[%s] Host[%s:%s]",
 730                                         ptr->cs_pid,
 731                                         ptr->client_socket,
 732                                         ptr->curr_user,
 733                                         ptr->cs_host,
 734                                         ptr->cs_addr
 735                                 );
 736                                 ptr->kill_me = 1;
 737                                 ptr->client_socket = -1;
 738                                 break;
 739                         }
 740                 }
 741         }
 742         end_critical_section(S_SESSION_TABLE);
 743
 744         // First, add the various master sockets to the fdset.
 745         for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next ) {
 746
 747                 // Initialize the fdset.
 748                 highest = 0;
 749                 tv.tv_sec = 0;          // wake up every second if no input
 750                 tv.tv_usec = 0;
 751
 752                 FD_SET(serviceptr->msock, &readfds);
 753                 if (serviceptr->msock > highest) {
 754                         highest = serviceptr->msock;
 755                 }
 756                 if ((select(highest + 1, &readfds, NULL, NULL, &tv) < 0) && (errno == EBADF)) {
 757                         // Gotcha! server socket dead? commit suicide!
 758                         syslog(LOG_ERR, "sysdep: found bad FD: %d and its a server socket! Shutting Down!", serviceptr->msock);
 759                         server_shutting_down = 1;
 760                         break;
 761                 }
 762         }
 763 }
 764
 765
 766 // Main server loop
 767 // select() can wake up on any of the following conditions:
 768 // 1. A new client connection on a master socket
 769 // 2. Received data on a client socket
 770 // 3. A timer event
 771 // That's why we are blocking on select() and not accept().
 772 void *worker_thread(void *blah) {
 773         int highest;
 774         CitContext *ptr;
 775         CitContext *bind_me = NULL;
 776         fd_set readfds;
 777         int retval = 0;
 778         struct timeval tv;
 779         int force_purge = 0;
 780         struct ServiceFunctionHook *serviceptr;
 781         int ssock;                      // Descriptor for client socket
 782         CitContext *con = NULL;         // Temporary context pointer
 783         int i;
 784
 785         pthread_mutex_lock(&ThreadCountMutex);
 786         ++num_workers;
 787         pthread_mutex_unlock(&ThreadCountMutex);
 788
 789         while (!server_shutting_down) {
 790
 791                 // make doubly sure we're not holding any stale db handles which might cause a deadlock
 792                 cdb_check_handles();
 793 do_select:      force_purge = 0;
 794                 bind_me = NULL;         // Which session shall we handle?
 795
 796                 // Initialize the fdset
 797                 FD_ZERO(&readfds);
 798                 highest = 0;
 799
 800                 // First, add the various master sockets to the fdset.
 801                 for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next ) {
 802                         FD_SET(serviceptr->msock, &readfds);
 803                         if (serviceptr->msock > highest) {
 804                                 highest = serviceptr->msock;
 805                         }
 806                 }
 807
 808                 // Next, add all of the client sockets.
 809                 begin_critical_section(S_SESSION_TABLE);
 810                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 811                         if ((ptr->state == CON_SYS) && (ptr->client_socket == 0))
 812                             continue;
 813
 814                         // Don't select on dead sessions, only truly idle ones
 815                         if (    (ptr->state == CON_IDLE)
 816                                 && (ptr->kill_me == 0)
 817                                 && (ptr->client_socket > 0)
 818                         ) {
 819                                 FD_SET(ptr->client_socket, &readfds);
 820                                 if (ptr->client_socket > highest)
 821                                         highest = ptr->client_socket;
 822                         }
 823                         if ((bind_me == NULL) && (ptr->state == CON_READY)) {
 824                                 bind_me = ptr;
 825                                 ptr->state = CON_EXECUTING;
 826                                 break;
 827                         }
 828                         if ((bind_me == NULL) && (ptr->state == CON_GREETING)) {
 829                                 bind_me = ptr;
 830                                 ptr->state = CON_STARTING;
 831                                 break;
 832                         }
 833                 }
 834                 end_critical_section(S_SESSION_TABLE);
 835
 836                 if (bind_me) {
 837                         goto SKIP_SELECT;
 838                 }
 839
 840                 // If we got this far, it means that there are no sessions
 841                 // which a previous thread marked for attention, so we go
 842                 // ahead and get ready to select().
 843
 844                 if (!server_shutting_down) {
 845                         tv.tv_sec = 1;          // wake up every second if no input
 846                         tv.tv_usec = 0;
 847                         retval = select(highest + 1, &readfds, NULL, NULL, &tv);
 848                 }
 849                 else {
 850                         --num_workers;
 851                         return NULL;
 852                 }
 853
 854                 // Now figure out who made this select() unblock.
 855                 // First, check for an error or exit condition.
 856                 if (retval < 0) {
 857                         if (errno == EBADF) {
 858                                 syslog(LOG_ERR, "sysdep: select() failed: %m");
 859                                 HuntBadSession();
 860                                 goto do_select;
 861                         }
 862                         if (errno != EINTR) {
 863                                 syslog(LOG_ERR, "sysdep: exiting: %m");
 864                                 server_shutting_down = 1;
 865                                 continue;
 866                         } else {
 867                                 if (server_shutting_down) {
 868                                         --num_workers;
 869                                         return(NULL);
 870                                 }
 871                                 goto do_select;
 872                         }
 873                 }
 874                 else if (retval == 0) {
 875                         if (server_shutting_down) {
 876                                 --num_workers;
 877                                 return(NULL);
 878                         }
 879                 }
 880
 881                 // Next, check to see if it's a new client connecting on a master socket.
 882
 883                 else if ((retval > 0) && (!server_shutting_down)) for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next) {
 884
 885                         if (FD_ISSET(serviceptr->msock, &readfds)) {
 886                                 ssock = accept(serviceptr->msock, NULL, 0);
 887                                 if (ssock >= 0) {
 888                                         syslog(LOG_DEBUG, "sysdep: new client socket %d", ssock);
 889
 890                                         // The master socket is non-blocking but the client
 891                                         // sockets need to be blocking, otherwise certain
 892                                         // operations barf on FreeBSD.  Not a fatal error.
 893                                         if (fcntl(ssock, F_SETFL, 0) < 0) {
 894                                                 syslog(LOG_ERR, "sysdep: Can't set socket to blocking: %m");
 895                                         }
 896
 897                                         // New context will be created already
 898                                         // set up in the CON_EXECUTING state.
 899                                         con = CreateNewContext();
 900
 901                                         // Assign our new socket number to it.
 902                                         con->tcp_port = serviceptr->tcp_port;
 903                                         con->client_socket = ssock;
 904                                         con->h_command_function = serviceptr->h_command_function;
 905                                         con->h_async_function = serviceptr->h_async_function;
 906                                         con->h_greeting_function = serviceptr->h_greeting_function;
 907                                         con->ServiceName = serviceptr->ServiceName;
 908
 909                                         // Connections on a local client are always from the same host
 910                                         if (serviceptr->sockpath != NULL) {
 911                                                 con->is_local_client = 1;
 912                                         }
 913
 914                                         // Set the SO_REUSEADDR socket option
 915                                         i = 1;
 916                                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 917                                         con->state = CON_GREETING;
 918                                         retval--;
 919                                         if (retval == 0)
 920                                                 break;
 921                                 }
 922                         }
 923                 }
 924
 925                 // It must be a client socket.  Find a context that has data
 926                 // waiting on its socket *and* is in the CON_IDLE state.  Any
 927                 // active sockets other than our chosen one are marked as
 928                 // CON_READY so the next thread that comes around can just bind
 929                 // to one without having to select() again.
 930                 begin_critical_section(S_SESSION_TABLE);
 931                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 932                         int checkfd = ptr->client_socket;
 933                         if ((checkfd != -1) && (ptr->state == CON_IDLE) ){
 934                                 if (FD_ISSET(checkfd, &readfds)) {
 935                                         ptr->input_waiting = 1;
 936                                         if (!bind_me) {
 937                                                 bind_me = ptr;  // I choose you!
 938                                                 bind_me->state = CON_EXECUTING;
 939                                         }
 940                                         else {
 941                                                 ptr->state = CON_READY;
 942                                         }
 943                                 } else if ((ptr->is_async) && (ptr->async_waiting) && (ptr->h_async_function)) {
 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                                 }
 952                         }
 953                 }
 954                 end_critical_section(S_SESSION_TABLE);
 955
 956 SKIP_SELECT:
 957                 // We're bound to a session
 958                 pthread_mutex_lock(&ThreadCountMutex);
 959                 ++active_workers;
 960                 pthread_mutex_unlock(&ThreadCountMutex);
 961
 962                 if (bind_me != NULL) {
 963                         become_session(bind_me);
 964
 965                         if (bind_me->state == CON_STARTING) {
 966                                 bind_me->state = CON_EXECUTING;
 967                                 begin_session(bind_me);
 968                                 bind_me->h_greeting_function();
 969                         }
 970                         // If the client has sent a command, execute it.
 971                         if (CC->input_waiting) {
 972                                 CC->h_command_function();
 973
 974                                 while (HaveMoreLinesWaiting(CC))
 975                                        CC->h_command_function();
 976
 977                                 CC->input_waiting = 0;
 978                         }
 979
 980                         // If there are asynchronous messages waiting and the client supports it, do those now
 981                         if ((CC->is_async) && (CC->async_waiting) && (CC->h_async_function != NULL)) {
 982                                 CC->h_async_function();
 983                                 CC->async_waiting = 0;
 984                         }
 985
 986                         force_purge = CC->kill_me;
 987                         become_session(NULL);
 988                         bind_me->state = CON_IDLE;
 989                 }
 990
 991                 dead_session_purge(force_purge);
 992                 do_housekeeping();
 993
 994                 pthread_mutex_lock(&ThreadCountMutex);
 995                 --active_workers;
 996                 if ((active_workers + CtdlGetConfigInt("c_min_workers") < num_workers) &&
 997                     (num_workers > CtdlGetConfigInt("c_min_workers")))
 998                 {
 999                         num_workers--;
1000                         pthread_mutex_unlock(&ThreadCountMutex);
1001                         return (NULL);
1002                 }
1003                 pthread_mutex_unlock(&ThreadCountMutex);
1004         }
1005
1006         // If control reaches this point, the server is shutting down
1007         pthread_mutex_lock(&ThreadCountMutex);
1008         --num_workers;
1009         pthread_mutex_unlock(&ThreadCountMutex);
1010         return(NULL);
1011 }
1012
1013
1014 // SyslogFacility()
1015 // Translate text facility name to syslog.h defined value.
1016 int SyslogFacility(char *name)
1017 {
1018         int i;
1019         struct
1020         {
1021                 int facility;
1022                 char *name;
1023         }   facTbl[] =
1024         {
1025                 {   LOG_KERN,   "kern"          },
1026                 {   LOG_USER,   "user"          },
1027                 {   LOG_MAIL,   "mail"          },
1028                 {   LOG_DAEMON, "daemon"        },
1029                 {   LOG_AUTH,   "auth"          },
1030                 {   LOG_SYSLOG, "syslog"        },
1031                 {   LOG_LPR,    "lpr"           },
1032                 {   LOG_NEWS,   "news"          },
1033                 {   LOG_UUCP,   "uucp"          },
1034                 {   LOG_LOCAL0, "local0"        },
1035                 {   LOG_LOCAL1, "local1"        },
1036                 {   LOG_LOCAL2, "local2"        },
1037                 {   LOG_LOCAL3, "local3"        },
1038                 {   LOG_LOCAL4, "local4"        },
1039                 {   LOG_LOCAL5, "local5"        },
1040                 {   LOG_LOCAL6, "local6"        },
1041                 {   LOG_LOCAL7, "local7"        },
1042                 {   0,            NULL          }
1043         };
1044         for(i = 0; facTbl[i].name != NULL; i++) {
1045                 if(!strcasecmp(name, facTbl[i].name))
1046                         return facTbl[i].facility;
1047         }
1048         return LOG_DAEMON;
1049 }