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