citadel/sysdep.c

   1 /*
   2  * Citadel "system dependent" stuff.
   3  *
   4  * Here's where we (hopefully) have most parts of the Citadel server that
   5  * might need tweaking when run on different operating system variants.
   6  *
   7  * Copyright (c) 1987-2021 by the citadel.org team
   8  *
   9  * This program is open source software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License, version 3.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include "sysdep.h"
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <sys/stat.h>
  22 #include <errno.h>
  23 #include <signal.h>
  24 #include <stdio.h>
  25 #include <syslog.h>
  26 #include <sys/syslog.h>
  27 #include <netdb.h>
  28 #include <sys/un.h>
  29 #include <sys/types.h>
  30 #include <sys/socket.h>
  31 #include <netinet/in.h>
  32 #include <arpa/inet.h>
  33 #include <netinet/tcp.h>
  34 #include <arpa/inet.h>
  35 #define SHOW_ME_VAPPEND_PRINTF
  36 #include <libcitadel.h>
  37 #include "citserver.h"
  38 #include "config.h"
  39 #include "ctdl_module.h"
  40 #include "sysdep_decls.h"
  41 #include "modules/crypto/serv_crypto.h" /* Needed for init_ssl, client_write_ssl, client_read_ssl, destruct_ssl */
  42 #include "housekeeping.h"
  43 #include "context.h"
  44
  45 /*
  46  * Signal handler to shut down the server.
  47  */
  48
  49 volatile int exit_signal = 0;
  50 volatile int shutdown_and_halt = 0;
  51 volatile int restart_server = 0;
  52 volatile int running_as_daemon = 0;
  53
  54
  55 static RETSIGTYPE signal_cleanup(int signum) {
  56         syslog(LOG_DEBUG, "sysdep: caught signal %d; shutting down.", signum);
  57         exit_signal = signum;
  58         server_shutting_down = 1;
  59 }
  60
  61
  62 static RETSIGTYPE signal_exit(int signum) {
  63         exit(1);
  64 }
  65
  66
  67 /*
  68  * Some initialization stuff...
  69  */
  70 void init_sysdep(void) {
  71         sigset_t set;
  72
  73         /* Avoid vulnerabilities related to FD_SETSIZE if we can. */
  74 #ifdef FD_SETSIZE
  75 #ifdef RLIMIT_NOFILE
  76         struct rlimit rl;
  77         getrlimit(RLIMIT_NOFILE, &rl);
  78         rl.rlim_cur = FD_SETSIZE;
  79         rl.rlim_max = FD_SETSIZE;
  80         setrlimit(RLIMIT_NOFILE, &rl);
  81 #endif
  82 #endif
  83
  84         /* If we've got OpenSSL, we're going to use it. */
  85 #ifdef HAVE_OPENSSL
  86         init_ssl();
  87 #endif
  88
  89         if (pthread_key_create(&ThreadKey, NULL) != 0) {                        // TSD for threads
  90                 syslog(LOG_ERR, "pthread_key_create() : %m");
  91                 abort();
  92         }
  93
  94         if (pthread_key_create(&MyConKey, NULL) != 0) {                         // TSD for sessions
  95                 syslog(LOG_CRIT, "sysdep: can't create TSD key: %m");
  96                 abort();
  97         }
  98
  99         /*
 100          * Interript, hangup, and terminate signals should cause the server
 101          * to gracefully clean up and shut down.
 102          */
 103         sigemptyset(&set);
 104         sigaddset(&set, SIGINT);
 105         sigaddset(&set, SIGHUP);
 106         sigaddset(&set, SIGTERM);
 107         sigprocmask(SIG_UNBLOCK, &set, NULL);
 108
 109         signal(SIGINT, signal_cleanup);
 110         signal(SIGHUP, signal_cleanup);
 111         signal(SIGTERM, signal_cleanup);
 112         signal(SIGUSR2, signal_exit);
 113
 114         /*
 115          * Do not shut down the server on broken pipe signals, otherwise the
 116          * whole Citadel service would come down whenever a single client
 117          * socket breaks.
 118          */
 119         signal(SIGPIPE, SIG_IGN);
 120 }
 121
 122
 123 /*
 124  * This is a generic function to set up a master socket for listening on
 125  * a TCP port.  The server shuts down if the bind fails.  (IPv4/IPv6 version)
 126  *
 127  * ip_addr      IP address to bind
 128  * port_number  port number to bind
 129  * queue_len    number of incoming connections to allow in the queue
 130  */
 131 int ctdl_tcp_server(char *ip_addr, int port_number, int queue_len)
 132 {
 133         struct protoent *p;
 134         struct sockaddr_in6 sin6;
 135         struct sockaddr_in sin4;
 136         int s, i, b;
 137         int ip_version = 6;
 138
 139         memset(&sin6, 0, sizeof(sin6));
 140         memset(&sin4, 0, sizeof(sin4));
 141         sin6.sin6_family = AF_INET6;
 142         sin4.sin_family = AF_INET;
 143
 144         if (    (ip_addr == NULL)                                                       /* any IPv6 */
 145                 || (IsEmptyStr(ip_addr))
 146                 || (!strcmp(ip_addr, "*"))
 147         ) {
 148                 ip_version = 6;
 149                 sin6.sin6_addr = in6addr_any;
 150         }
 151         else if (!strcmp(ip_addr, "0.0.0.0"))                                           /* any IPv4 */
 152         {
 153                 ip_version = 4;
 154                 sin4.sin_addr.s_addr = INADDR_ANY;
 155         }
 156         else if ((strchr(ip_addr, '.')) && (!strchr(ip_addr, ':')))                     /* specific IPv4 */
 157         {
 158                 ip_version = 4;
 159                 if (inet_pton(AF_INET, ip_addr, &sin4.sin_addr) <= 0) {
 160                         syslog(LOG_ALERT, "tcpserver: inet_pton: %m");
 161                         return (-1);
 162                 }
 163         }
 164         else                                                                            /* specific IPv6 */
 165         {
 166                 ip_version = 6;
 167                 if (inet_pton(AF_INET6, ip_addr, &sin6.sin6_addr) <= 0) {
 168                         syslog(LOG_ALERT, "tcpserver: inet_pton: %m");
 169                         return (-1);
 170                 }
 171         }
 172
 173         if (port_number == 0) {
 174                 syslog(LOG_ALERT, "tcpserver: no port number was specified");
 175                 return (-1);
 176         }
 177         sin6.sin6_port = htons((u_short) port_number);
 178         sin4.sin_port = htons((u_short) port_number);
 179
 180         p = getprotobyname("tcp");
 181         if (p == NULL) {
 182                 syslog(LOG_ALERT, "tcpserver: getprotobyname: %m");
 183                 return (-1);
 184         }
 185
 186         s = socket( ((ip_version == 6) ? PF_INET6 : PF_INET), SOCK_STREAM, (p->p_proto));
 187         if (s < 0) {
 188                 syslog(LOG_ALERT, "tcpserver: socket: %m");
 189                 return (-1);
 190         }
 191         /* Set some socket options that make sense. */
 192         i = 1;
 193         setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 194
 195         if (ip_version == 6) {
 196                 b = bind(s, (struct sockaddr *) &sin6, sizeof(sin6));
 197         }
 198         else {
 199                 b = bind(s, (struct sockaddr *) &sin4, sizeof(sin4));
 200         }
 201
 202         if (b < 0) {
 203                 syslog(LOG_ALERT, "tcpserver: bind: %m");
 204                 return (-1);
 205         }
 206
 207         fcntl(s, F_SETFL, O_NONBLOCK);
 208
 209         if (listen(s, ((queue_len >= 5) ? queue_len : 5) ) < 0) {
 210                 syslog(LOG_ALERT, "tcpserver: listen: %m");
 211                 return (-1);
 212         }
 213         return (s);
 214 }
 215
 216
 217 /*
 218  * Create a Unix domain socket and listen on it
 219  */
 220 int ctdl_uds_server(char *sockpath, int queue_len)
 221 {
 222         struct sockaddr_un addr;
 223         int s;
 224         int i;
 225         int actual_queue_len;
 226 #ifdef HAVE_STRUCT_UCRED
 227         int passcred = 1;
 228 #endif
 229
 230         actual_queue_len = queue_len;
 231         if (actual_queue_len < 5) actual_queue_len = 5;
 232
 233         i = unlink(sockpath);
 234         if ((i != 0) && (errno != ENOENT)) {
 235                 syslog(LOG_ERR, "udsserver: %m");
 236                 return(-1);
 237         }
 238
 239         memset(&addr, 0, sizeof(addr));
 240         addr.sun_family = AF_UNIX;
 241         safestrncpy(addr.sun_path, sockpath, sizeof addr.sun_path);
 242
 243         s = socket(AF_UNIX, SOCK_STREAM, 0);
 244         if (s < 0) {
 245                 syslog(LOG_ERR, "udsserver: socket: %m");
 246                 return(-1);
 247         }
 248
 249         if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
 250                 syslog(LOG_ERR, "udsserver: bind: %m");
 251                 return(-1);
 252         }
 253
 254         /* set to nonblock - we need this for some obscure situations */
 255         if (fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
 256                 syslog(LOG_ERR, "udsserver: fcntl: %m");
 257                 close(s);
 258                 return(-1);
 259         }
 260
 261         if (listen(s, actual_queue_len) < 0) {
 262                 syslog(LOG_ERR, "udsserver: listen: %m");
 263                 return(-1);
 264         }
 265
 266 #ifdef HAVE_STRUCT_UCRED
 267         setsockopt(s, SOL_SOCKET, SO_PASSCRED, &passcred, sizeof(passcred));
 268 #endif
 269
 270         chmod(sockpath, S_ISGID|S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IWGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH);
 271         return(s);
 272 }
 273
 274
 275 /*
 276  * The following functions implement output buffering on operating systems which
 277  * support it (such as Linux and various BSD flavors).
 278  */
 279 #ifndef HAVE_DARWIN
 280 #ifdef TCP_CORK
 281 #       define HAVE_TCP_BUFFERING
 282 #else
 283 #       ifdef TCP_NOPUSH
 284 #               define HAVE_TCP_BUFFERING
 285 #               define TCP_CORK TCP_NOPUSH
 286 #       endif
 287 #endif /* TCP_CORK */
 288 #endif /* HAVE_DARWIN */
 289
 290 static unsigned on = 1, off = 0;
 291
 292 void buffer_output(void) {
 293 #ifdef HAVE_TCP_BUFFERING
 294 #ifdef HAVE_OPENSSL
 295         if (!CC->redirect_ssl)
 296 #endif
 297                 setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
 298 #endif
 299 }
 300
 301 void unbuffer_output(void) {
 302 #ifdef HAVE_TCP_BUFFERING
 303 #ifdef HAVE_OPENSSL
 304         if (!CC->redirect_ssl)
 305 #endif
 306                 setsockopt(CC->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
 307 #endif
 308 }
 309
 310 void flush_output(void) {
 311 #ifdef HAVE_TCP_BUFFERING
 312         struct CitContext *CCC = CC;
 313         setsockopt(CCC->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
 314         setsockopt(CCC->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
 315 #endif
 316 }
 317
 318 /*
 319 static void flush_client_inbuf(void)
 320 {
 321         CitContext *CCC=CC;
 322
 323         FlushStrBuf(CCC->ReadBuf);
 324         CCC->RecvBuf->ReadWritePointer = NULL;
 325 }
 326 */
 327
 328
 329 /*
 330  * client_close()       ...     close the client socket
 331  */
 332 void client_close(void) {
 333         CitContext *CCC = CC;
 334
 335         if (!CCC) return;
 336         if (CCC->client_socket <= 0) return;
 337         syslog(LOG_DEBUG, "sysdep: closing socket %d", CCC->client_socket);
 338         close(CCC->client_socket);
 339         CCC->client_socket = -1 ;
 340 }
 341
 342
 343 /*
 344  * client_write()   ...    Send binary data to the client.
 345  */
 346 int client_write(const char *buf, int nbytes)
 347 {
 348         int bytes_written = 0;
 349         int retval;
 350 #ifndef HAVE_TCP_BUFFERING
 351         int old_buffer_len = 0;
 352 #endif
 353         fd_set wset;
 354         CitContext *Ctx;
 355         int fdflags;
 356
 357         if (nbytes < 1) return(0);
 358
 359         Ctx = CC;
 360
 361         if (Ctx->redirect_buffer != NULL) {
 362                 StrBufAppendBufPlain(Ctx->redirect_buffer,
 363                                      buf, nbytes, 0);
 364                 return 0;
 365         }
 366
 367 #ifdef HAVE_OPENSSL
 368         if (Ctx->redirect_ssl) {
 369                 client_write_ssl(buf, nbytes);
 370                 return 0;
 371         }
 372 #endif
 373         if (Ctx->client_socket == -1) return -1;
 374
 375         fdflags = fcntl(Ctx->client_socket, F_GETFL);
 376
 377         while ((bytes_written < nbytes) && (Ctx->client_socket != -1)){
 378                 if ((fdflags & O_NONBLOCK) == O_NONBLOCK) {
 379                         FD_ZERO(&wset);
 380                         FD_SET(Ctx->client_socket, &wset);
 381                         if (select(1, NULL, &wset, NULL, NULL) == -1) {
 382                                 if (errno == EINTR)
 383                                 {
 384                                         syslog(LOG_DEBUG, "sysdep: client_write(%d bytes) select() interrupted.", nbytes-bytes_written);
 385                                         if (server_shutting_down) {
 386                                                 CC->kill_me = KILLME_SELECT_INTERRUPTED;
 387                                                 return (-1);
 388                                         } else {
 389                                                 /* can't trust fd's and stuff so we need to re-create them */
 390                                                 continue;
 391                                         }
 392                                 } else {
 393                                         syslog(LOG_ERR, "sysdep: client_write(%d bytes) select failed: %m", nbytes - bytes_written);
 394                                         client_close();
 395                                         Ctx->kill_me = KILLME_SELECT_FAILED;
 396                                         return -1;
 397                                 }
 398                         }
 399                 }
 400
 401                 retval = write(Ctx->client_socket, &buf[bytes_written], nbytes - bytes_written);
 402                 if (retval < 1) {
 403                         syslog(LOG_ERR, "sysdep: client_write(%d bytes) failed: %m", nbytes - bytes_written);
 404                         client_close();
 405                         Ctx->kill_me = KILLME_WRITE_FAILED;
 406                         return -1;
 407                 }
 408                 bytes_written = bytes_written + retval;
 409         }
 410         return 0;
 411 }
 412
 413 void cputbuf(const StrBuf *Buf) {
 414         client_write(ChrPtr(Buf), StrLength(Buf));
 415 }
 416
 417
 418 /*
 419  * cprintf()    Send formatted printable data to the client.
 420  *              Implemented in terms of client_write() so it's technically not sysdep...
 421  */
 422 void cprintf(const char *format, ...) {
 423         va_list arg_ptr;
 424         char buf[1024];
 425
 426         va_start(arg_ptr, format);
 427         if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
 428                 buf[sizeof buf - 2] = '\n';
 429         client_write(buf, strlen(buf));
 430         va_end(arg_ptr);
 431 }
 432
 433
 434 /*
 435  * Read data from the client socket.
 436  *
 437  * sock         socket fd to read from
 438  * buf          buffer to read into
 439  * bytes        number of bytes to read
 440  * timeout      Number of seconds to wait before timing out
 441  *
 442  * Possible return values:
 443  *      1       Requested number of bytes has been read.
 444  *      0       Request timed out.
 445  *      -1      Connection is broken, or other error.
 446  */
 447 int client_read_blob(StrBuf *Target, int bytes, int timeout)
 448 {
 449         CitContext *CCC=CC;
 450         const char *Error;
 451         int retval = 0;
 452
 453 #ifdef HAVE_OPENSSL
 454         if (CCC->redirect_ssl) {
 455                 retval = client_read_sslblob(Target, bytes, timeout);
 456                 if (retval < 0) {
 457                         syslog(LOG_ERR, "sysdep: client_read_blob() failed");
 458                 }
 459         }
 460         else
 461 #endif
 462         {
 463                 retval = StrBufReadBLOBBuffered(Target,
 464                                                 CCC->RecvBuf.Buf,
 465                                                 &CCC->RecvBuf.ReadWritePointer,
 466                                                 &CCC->client_socket,
 467                                                 1,
 468                                                 bytes,
 469                                                 O_TERM,
 470                                                 &Error
 471                 );
 472                 if (retval < 0) {
 473                         syslog(LOG_ERR, "sysdep: client_read_blob() failed: %s", Error);
 474                         client_close();
 475                         return retval;
 476                 }
 477         }
 478         return retval;
 479 }
 480
 481
 482 /*
 483  * to make client_read_random_blob() more efficient, increase buffer size.
 484  * just use in greeting function, else your buffer may be flushed
 485  */
 486 void client_set_inbound_buf(long N)
 487 {
 488         CitContext *CCC=CC;
 489         FlushStrBuf(CCC->RecvBuf.Buf);
 490         ReAdjustEmptyBuf(CCC->RecvBuf.Buf, N * SIZ, N * SIZ);
 491 }
 492
 493 int client_read_random_blob(StrBuf *Target, int timeout)
 494 {
 495         CitContext *CCC=CC;
 496         int rc;
 497
 498         rc =  client_read_blob(Target, 1, timeout);
 499         if (rc > 0)
 500         {
 501                 long len;
 502                 const char *pch;
 503
 504                 len = StrLength(CCC->RecvBuf.Buf);
 505                 pch = ChrPtr(CCC->RecvBuf.Buf);
 506
 507                 if (len > 0)
 508                 {
 509                         if (CCC->RecvBuf.ReadWritePointer != NULL) {
 510                                 len -= CCC->RecvBuf.ReadWritePointer - pch;
 511                                 pch = CCC->RecvBuf.ReadWritePointer;
 512                         }
 513                         StrBufAppendBufPlain(Target, pch, len, 0);
 514                         FlushStrBuf(CCC->RecvBuf.Buf);
 515                         CCC->RecvBuf.ReadWritePointer = NULL;
 516                         return StrLength(Target);
 517                 }
 518                 return rc;
 519         }
 520         else
 521                 return rc;
 522 }
 523
 524 int client_read_to(char *buf, int bytes, int timeout)
 525 {
 526         CitContext *CCC=CC;
 527         int rc;
 528
 529         rc = client_read_blob(CCC->MigrateBuf, bytes, timeout);
 530         if (rc < 0)
 531         {
 532                 *buf = '\0';
 533                 return rc;
 534         }
 535         else
 536         {
 537                 memcpy(buf,
 538                        ChrPtr(CCC->MigrateBuf),
 539                        StrLength(CCC->MigrateBuf) + 1);
 540                 FlushStrBuf(CCC->MigrateBuf);
 541                 return rc;
 542         }
 543 }
 544
 545
 546 int HaveMoreLinesWaiting(CitContext *CCC) {
 547         if ((CCC->kill_me != 0) ||
 548             ( (CCC->RecvBuf.ReadWritePointer == NULL) &&
 549               (StrLength(CCC->RecvBuf.Buf) == 0) &&
 550               (CCC->client_socket != -1)) )
 551                 return 0;
 552         else
 553                 return 1;
 554 }
 555
 556
 557 /*
 558  * Read data from the client socket with default timeout.
 559  * (This is implemented in terms of client_read_to() and could be
 560  * justifiably moved out of sysdep.c)
 561  */
 562 INLINE int client_read(char *buf, int bytes) {
 563         return(client_read_to(buf, bytes, CtdlGetConfigInt("c_sleeping")));
 564 }
 565
 566 int CtdlClientGetLine(StrBuf *Target) {
 567         CitContext *CCC=CC;
 568         const char *Error;
 569         int rc;
 570
 571         FlushStrBuf(Target);
 572 #ifdef HAVE_OPENSSL
 573         if (CCC->redirect_ssl) {
 574                 rc = client_readline_sslbuffer(Target, CCC->RecvBuf.Buf, &CCC->RecvBuf.ReadWritePointer, 1);
 575                 return rc;
 576         }
 577         else
 578 #endif
 579         {
 580                 rc = StrBufTCP_read_buffered_line_fast(Target,
 581                                                        CCC->RecvBuf.Buf,
 582                                                        &CCC->RecvBuf.ReadWritePointer,
 583                                                        &CCC->client_socket,
 584                                                        5,
 585                                                        1,
 586                                                        &Error
 587                 );
 588                 return rc;
 589         }
 590 }
 591
 592
 593 /*
 594  * client_getln()   ...   Get a LF-terminated line of text from the client.
 595  * (This is implemented in terms of client_read() and could be
 596  * justifiably moved out of sysdep.c)
 597  */
 598 int client_getln(char *buf, int bufsize) {
 599         int i, retval;
 600         CitContext *CCC=CC;
 601         const char *pCh;
 602
 603         retval = CtdlClientGetLine(CCC->MigrateBuf);
 604         if (retval < 0)
 605           return(retval >= 0);
 606
 607
 608         i = StrLength(CCC->MigrateBuf);
 609         pCh = ChrPtr(CCC->MigrateBuf);
 610         /* Strip the trailing LF, and the trailing CR if present.
 611          */
 612         if (bufsize <= i)
 613                 i = bufsize - 1;
 614         while ( (i > 0)
 615                 && ( (pCh[i - 1]==13)
 616                      || ( pCh[i - 1]==10)) ) {
 617                 i--;
 618         }
 619         memcpy(buf, pCh, i);
 620         buf[i] = 0;
 621
 622         FlushStrBuf(CCC->MigrateBuf);
 623         if (retval < 0) {
 624                 safestrncpy(&buf[i], "000", bufsize - i);
 625         }
 626         return(retval >= 0);
 627 }
 628
 629
 630 /*
 631  * Cleanup any contexts that are left lying around
 632  */
 633 void close_masters(void) {
 634         struct ServiceFunctionHook *serviceptr;
 635         const char *Text;
 636
 637         /*
 638          * close all protocol master sockets
 639          */
 640         for (serviceptr = ServiceHookTable; serviceptr != NULL;
 641             serviceptr = serviceptr->next ) {
 642
 643                 if (serviceptr->tcp_port > 0) {
 644                         if (serviceptr->msock == -1) {
 645                                 Text = "not closing again";
 646                         }
 647                         else {
 648                                 Text = "Closing";
 649                         }
 650                         syslog(LOG_INFO, "sysdep: %s %d listener on port %d",
 651                                Text,
 652                                serviceptr->msock,
 653                                serviceptr->tcp_port
 654                         );
 655                         serviceptr->tcp_port = 0;
 656                 }
 657
 658                 if (serviceptr->sockpath != NULL) {
 659                         if (serviceptr->msock == -1) {
 660                                 Text = "not closing again";
 661                         }
 662                         else {
 663                                 Text = "Closing";
 664                         }
 665                         syslog(LOG_INFO, "sysdep: %s %d listener on '%s'",
 666                                Text,
 667                                serviceptr->msock,
 668                                serviceptr->sockpath
 669                         );
 670                 }
 671
 672                 if (serviceptr->msock != -1) {
 673                         close(serviceptr->msock);
 674                         serviceptr->msock = -1;
 675                 }
 676
 677                 /* If it's a Unix domain socket, remove the file. */
 678                 if (serviceptr->sockpath != NULL) {
 679                         unlink(serviceptr->sockpath);
 680                         serviceptr->sockpath = NULL;
 681                 }
 682         }
 683 }
 684
 685
 686 /*
 687  * The system-dependent part of master_cleanup() - close the master socket.
 688  */
 689 void sysdep_master_cleanup(void) {
 690         close_masters();
 691         context_cleanup();
 692 #ifdef HAVE_OPENSSL
 693         destruct_ssl();
 694 #endif
 695 }
 696
 697
 698
 699 pid_t current_child;
 700 void graceful_shutdown(int signum) {
 701         kill(current_child, signum);
 702         unlink(file_pid_file);
 703         exit(0);
 704 }
 705
 706 int nFireUps = 0;
 707 int nFireUpsNonRestart = 0;
 708 pid_t ForkedPid = 1;
 709
 710 /*
 711  * Start running as a daemon.
 712  */
 713 void start_daemon(int unused) {
 714         int status = 0;
 715         pid_t child = 0;
 716         FILE *fp;
 717         int do_restart = 0;
 718         current_child = 0;
 719
 720         //if (chdir(ctdl_run_dir) != 0) {
 721                 //syslog(LOG_ERR, "%s: %m", ctdl_run_dir);
 722         //}
 723
 724         /* Close stdin/stdout/stderr and replace them with /dev/null.
 725          * We don't just call close() because we don't want these fd's
 726          * to be reused for other files.
 727          */
 728         child = fork();
 729         if (child != 0) {
 730                 exit(0);
 731         }
 732
 733         signal(SIGHUP, SIG_IGN);
 734         signal(SIGINT, SIG_IGN);
 735         signal(SIGQUIT, SIG_IGN);
 736
 737         setsid();
 738         umask(0);
 739         if (    (freopen("/dev/null", "r", stdin) != stdin) ||
 740                 (freopen("/dev/null", "w", stdout) != stdout) ||
 741                 (freopen("/dev/null", "w", stderr) != stderr)
 742         ) {
 743                 syslog(LOG_ERR, "sysdep: unable to reopen stdio: %m");
 744         }
 745
 746         do {
 747                 current_child = fork();
 748                 signal(SIGTERM, graceful_shutdown);
 749                 if (current_child < 0) {
 750                         perror("fork");
 751                         exit(errno);
 752                 }
 753                 else if (current_child == 0) {
 754                         return; /* continue starting citadel. */
 755                 }
 756                 else {
 757                         fp = fopen(file_pid_file, "w");
 758                         if (fp != NULL) {
 759                                 fprintf(fp, ""F_PID_T"\n", getpid());
 760                                 fclose(fp);
 761                         }
 762                         waitpid(current_child, &status, 0);
 763                 }
 764                 nFireUpsNonRestart = nFireUps;
 765
 766                 /* Exit code 0 means the watcher should exit */
 767                 if (WIFEXITED(status) && (WEXITSTATUS(status) == CTDLEXIT_SHUTDOWN)) {
 768                         do_restart = 0;
 769                 }
 770
 771                 /* Exit code 101-109 means the watcher should exit */
 772                 else if (WIFEXITED(status) && (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109)) {
 773                         do_restart = 0;
 774                 }
 775
 776                 /* Any other exit code, or no exit code, means we should restart. */
 777                 else {
 778                         do_restart = 1;
 779                         nFireUps++;
 780                         ForkedPid = current_child;
 781                 }
 782
 783         } while (do_restart);
 784
 785         unlink(file_pid_file);
 786         exit(WEXITSTATUS(status));
 787 }
 788
 789
 790 void checkcrash(void) {
 791         if (nFireUpsNonRestart != nFireUps) {
 792                 StrBuf *CrashMail;
 793                 CrashMail = NewStrBuf();
 794                 syslog(LOG_ALERT, "sysdep: posting crash message");
 795                 StrBufPrintf(CrashMail,
 796                         " \n"
 797                         " The Citadel server process (citserver) terminated unexpectedly."
 798                         "\n \n"
 799                         " This could be the result of a bug in the server program, or some external "
 800                         "factor.\n \n"
 801                         " You can obtain more information about this by enabling core dumps.\n \n"
 802                         " For more information, please see:\n \n"
 803                         " http://citadel.org/doku.php?id=faq:mastering_your_os:gdb#how.do.i.make.my.system.produce.core-files"
 804                         "\n \n"
 805
 806                         " If you have already done this, the core dump is likely to be found at %score.%d\n"
 807                         ,
 808                         ctdl_run_dir, ForkedPid);
 809                 CtdlAideMessage(ChrPtr(CrashMail), "Citadel server process terminated unexpectedly");
 810                 FreeStrBuf(&CrashMail);
 811         }
 812 }
 813
 814
 815 /*
 816  * Generic routine to convert a login name to a full name (gecos)
 817  * Returns nonzero if a conversion took place
 818  */
 819 int convert_login(char NameToConvert[]) {
 820         struct passwd *pw;
 821         unsigned int a;
 822
 823         pw = getpwnam(NameToConvert);
 824         if (pw == NULL) {
 825                 return(0);
 826         }
 827         else {
 828                 strcpy(NameToConvert, pw->pw_gecos);
 829                 for (a=0; a<strlen(NameToConvert); ++a) {
 830                         if (NameToConvert[a] == ',') NameToConvert[a] = 0;
 831                 }
 832                 return(1);
 833         }
 834 }
 835
 836
 837 void HuntBadSession(void) {
 838         int highest;
 839         CitContext *ptr;
 840         fd_set readfds;
 841         struct timeval tv;
 842         struct ServiceFunctionHook *serviceptr;
 843
 844         /* Next, add all of the client sockets. */
 845         begin_critical_section(S_SESSION_TABLE);
 846         for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 847                 if ((ptr->state == CON_SYS) && (ptr->client_socket == 0))
 848                         continue;
 849                 /* Initialize the fdset. */
 850                 FD_ZERO(&readfds);
 851                 highest = 0;
 852                 tv.tv_sec = 0;          /* wake up every second if no input */
 853                 tv.tv_usec = 0;
 854
 855                 /* Don't select on dead sessions, only truly idle ones */
 856                 if (    (ptr->state == CON_IDLE)
 857                         && (ptr->kill_me == 0)
 858                         && (ptr->client_socket > 0)
 859                 ) {
 860                         FD_SET(ptr->client_socket, &readfds);
 861                         if (ptr->client_socket > highest)
 862                                 highest = ptr->client_socket;
 863
 864                         if ((select(highest + 1, &readfds, NULL, NULL, &tv) < 0) && (errno == EBADF))
 865                         {
 866                                 /* Gotcha! */
 867                                 syslog(LOG_ERR,
 868                                        "sysdep: killing session CC[%d] bad FD: [%d] User[%s] Host[%s:%s]",
 869                                         ptr->cs_pid,
 870                                         ptr->client_socket,
 871                                         ptr->curr_user,
 872                                         ptr->cs_host,
 873                                         ptr->cs_addr
 874                                 );
 875                                 ptr->kill_me = 1;
 876                                 ptr->client_socket = -1;
 877                                 break;
 878                         }
 879                 }
 880         }
 881         end_critical_section(S_SESSION_TABLE);
 882
 883         /* First, add the various master sockets to the fdset. */
 884         for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next ) {
 885
 886                 /* Initialize the fdset. */
 887                 highest = 0;
 888                 tv.tv_sec = 0;          /* wake up every second if no input */
 889                 tv.tv_usec = 0;
 890
 891                 FD_SET(serviceptr->msock, &readfds);
 892                 if (serviceptr->msock > highest) {
 893                         highest = serviceptr->msock;
 894                 }
 895                 if ((select(highest + 1, &readfds, NULL, NULL, &tv) < 0) &&
 896                     (errno == EBADF))
 897                 {
 898                         /* Gotcha! server socket dead? commit suicide! */
 899                         syslog(LOG_ERR, "sysdep: found bad FD: %d and its a server socket! Shutting Down!", serviceptr->msock);
 900                         server_shutting_down = 1;
 901                         break;
 902                 }
 903         }
 904 }
 905
 906
 907 /*
 908  * This loop just keeps going and going and going...
 909  */
 910 void *worker_thread(void *blah) {
 911         int highest;
 912         CitContext *ptr;
 913         CitContext *bind_me = NULL;
 914         fd_set readfds;
 915         int retval = 0;
 916         struct timeval tv;
 917         int force_purge = 0;
 918         struct ServiceFunctionHook *serviceptr;
 919         int ssock;                      /* Descriptor for client socket */
 920         CitContext *con = NULL;         /* Temporary context pointer */
 921         int i;
 922
 923         pthread_mutex_lock(&ThreadCountMutex);
 924         ++num_workers;
 925         pthread_mutex_unlock(&ThreadCountMutex);
 926
 927         while (!server_shutting_down) {
 928
 929                 /* make doubly sure we're not holding any stale db handles * which might cause a deadlock */
 930                 cdb_check_handles();
 931 do_select:      force_purge = 0;
 932                 bind_me = NULL;         /* Which session shall we handle? */
 933
 934                 /* Initialize the fdset. */
 935                 FD_ZERO(&readfds);
 936                 highest = 0;
 937
 938                 /* First, add the various master sockets to the fdset. */
 939                 for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next ) {
 940                         FD_SET(serviceptr->msock, &readfds);
 941                         if (serviceptr->msock > highest) {
 942                                 highest = serviceptr->msock;
 943                         }
 944                 }
 945
 946                 /* Next, add all of the client sockets. */
 947                 begin_critical_section(S_SESSION_TABLE);
 948                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
 949                         if ((ptr->state == CON_SYS) && (ptr->client_socket == 0))
 950                             continue;
 951
 952                         /* Don't select on dead sessions, only truly idle ones */
 953                         if (    (ptr->state == CON_IDLE)
 954                                 && (ptr->kill_me == 0)
 955                                 && (ptr->client_socket > 0)
 956                         ) {
 957                                 FD_SET(ptr->client_socket, &readfds);
 958                                 if (ptr->client_socket > highest)
 959                                         highest = ptr->client_socket;
 960                         }
 961                         if ((bind_me == NULL) && (ptr->state == CON_READY)) {
 962                                 bind_me = ptr;
 963                                 ptr->state = CON_EXECUTING;
 964                                 break;
 965                         }
 966                         if ((bind_me == NULL) && (ptr->state == CON_GREETING)) {
 967                                 bind_me = ptr;
 968                                 ptr->state = CON_STARTING;
 969                                 break;
 970                         }
 971                 }
 972                 end_critical_section(S_SESSION_TABLE);
 973
 974                 if (bind_me) {
 975                         goto SKIP_SELECT;
 976                 }
 977
 978                 /* If we got this far, it means that there are no sessions
 979                  * which a previous thread marked for attention, so we go
 980                  * ahead and get ready to select().
 981                  */
 982
 983                 if (!server_shutting_down) {
 984                         tv.tv_sec = 1;          /* wake up every second if no input */
 985                         tv.tv_usec = 0;
 986                         retval = select(highest + 1, &readfds, NULL, NULL, &tv);
 987                 }
 988                 else {
 989                         --num_workers;
 990                         return NULL;
 991                 }
 992
 993                 /* Now figure out who made this select() unblock.
 994                  * First, check for an error or exit condition.
 995                  */
 996                 if (retval < 0) {
 997                         if (errno == EBADF) {
 998                                 syslog(LOG_ERR, "sysdep: select() failed: %m");
 999                                 HuntBadSession();
1000                                 goto do_select;
1001                         }
1002                         if (errno != EINTR) {
1003                                 syslog(LOG_ERR, "sysdep: exiting: %m");
1004                                 server_shutting_down = 1;
1005                                 continue;
1006                         } else {
1007                                 if (server_shutting_down) {
1008                                         --num_workers;
1009                                         return(NULL);
1010                                 }
1011                                 goto do_select;
1012                         }
1013                 }
1014                 else if (retval == 0) {
1015                         if (server_shutting_down) {
1016                                 --num_workers;
1017                                 return(NULL);
1018                         }
1019                 }
1020
1021                 /* Next, check to see if it's a new client connecting on a master socket. */
1022
1023                 else if ((retval > 0) && (!server_shutting_down)) for (serviceptr = ServiceHookTable; serviceptr != NULL; serviceptr = serviceptr->next) {
1024
1025                         if (FD_ISSET(serviceptr->msock, &readfds)) {
1026                                 ssock = accept(serviceptr->msock, NULL, 0);
1027                                 if (ssock >= 0) {
1028                                         syslog(LOG_DEBUG, "sysdep: new client socket %d", ssock);
1029
1030                                         /* The master socket is non-blocking but the client
1031                                          * sockets need to be blocking, otherwise certain
1032                                          * operations barf on FreeBSD.  Not a fatal error.
1033                                          */
1034                                         if (fcntl(ssock, F_SETFL, 0) < 0) {
1035                                                 syslog(LOG_ERR, "sysdep: Can't set socket to blocking: %m");
1036                                         }
1037
1038                                         /* New context will be created already
1039                                          * set up in the CON_EXECUTING state.
1040                                          */
1041                                         con = CreateNewContext();
1042
1043                                         /* Assign our new socket number to it. */
1044                                         con->tcp_port = serviceptr->tcp_port;
1045                                         con->client_socket = ssock;
1046                                         con->h_command_function = serviceptr->h_command_function;
1047                                         con->h_async_function = serviceptr->h_async_function;
1048                                         con->h_greeting_function = serviceptr->h_greeting_function;
1049                                         con->ServiceName = serviceptr->ServiceName;
1050
1051                                         /* Connections on a local client are always from the same host */
1052                                         if (serviceptr->sockpath != NULL) {
1053                                                 con->is_local_client = 1;
1054                                         }
1055
1056                                         /* Set the SO_REUSEADDR socket option */
1057                                         i = 1;
1058                                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
1059                                         con->state = CON_GREETING;
1060                                         retval--;
1061                                         if (retval == 0)
1062                                                 break;
1063                                 }
1064                         }
1065                 }
1066
1067                 /* It must be a client socket.  Find a context that has data
1068                  * waiting on its socket *and* is in the CON_IDLE state.  Any
1069                  * active sockets other than our chosen one are marked as
1070                  * CON_READY so the next thread that comes around can just bind
1071                  * to one without having to select() again.
1072                  */
1073                 begin_critical_section(S_SESSION_TABLE);
1074                 for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
1075                         int checkfd = ptr->client_socket;
1076                         if ((checkfd != -1) && (ptr->state == CON_IDLE) ){
1077                                 if (FD_ISSET(checkfd, &readfds)) {
1078                                         ptr->input_waiting = 1;
1079                                         if (!bind_me) {
1080                                                 bind_me = ptr;  /* I choose you! */
1081                                                 bind_me->state = CON_EXECUTING;
1082                                         }
1083                                         else {
1084                                                 ptr->state = CON_READY;
1085                                         }
1086                                 } else if ((ptr->is_async) && (ptr->async_waiting) && (ptr->h_async_function)) {
1087                                         if (!bind_me) {
1088                                                 bind_me = ptr;  /* I choose you! */
1089                                                 bind_me->state = CON_EXECUTING;
1090                                         }
1091                                         else {
1092                                                 ptr->state = CON_READY;
1093                                         }
1094                                 }
1095                         }
1096                 }
1097                 end_critical_section(S_SESSION_TABLE);
1098
1099 SKIP_SELECT:
1100                 /* We're bound to a session */
1101                 pthread_mutex_lock(&ThreadCountMutex);
1102                 ++active_workers;
1103                 pthread_mutex_unlock(&ThreadCountMutex);
1104
1105                 if (bind_me != NULL) {
1106                         become_session(bind_me);
1107
1108                         if (bind_me->state == CON_STARTING) {
1109                                 bind_me->state = CON_EXECUTING;
1110                                 begin_session(bind_me);
1111                                 bind_me->h_greeting_function();
1112                         }
1113                         /* If the client has sent a command, execute it. */
1114                         if (CC->input_waiting) {
1115                                 CC->h_command_function();
1116
1117                                 while (HaveMoreLinesWaiting(CC))
1118                                        CC->h_command_function();
1119
1120                                 CC->input_waiting = 0;
1121                         }
1122
1123                         /* If there are asynchronous messages waiting and the client supports it, do those now */
1124                         if ((CC->is_async) && (CC->async_waiting) && (CC->h_async_function != NULL)) {
1125                                 CC->h_async_function();
1126                                 CC->async_waiting = 0;
1127                         }
1128
1129                         force_purge = CC->kill_me;
1130                         become_session(NULL);
1131                         bind_me->state = CON_IDLE;
1132                 }
1133
1134                 dead_session_purge(force_purge);
1135                 do_housekeeping();
1136
1137                 pthread_mutex_lock(&ThreadCountMutex);
1138                 --active_workers;
1139                 if ((active_workers + CtdlGetConfigInt("c_min_workers") < num_workers) &&
1140                     (num_workers > CtdlGetConfigInt("c_min_workers")))
1141                 {
1142                         num_workers--;
1143                         pthread_mutex_unlock(&ThreadCountMutex);
1144                         return (NULL);
1145                 }
1146                 pthread_mutex_unlock(&ThreadCountMutex);
1147         }
1148
1149         /* If control reaches this point, the server is shutting down */
1150         pthread_mutex_lock(&ThreadCountMutex);
1151         --num_workers;
1152         pthread_mutex_unlock(&ThreadCountMutex);
1153         return(NULL);
1154 }
1155
1156
1157 /*
1158  * SyslogFacility()
1159  * Translate text facility name to syslog.h defined value.
1160  */
1161 int SyslogFacility(char *name)
1162 {
1163         int i;
1164         struct
1165         {
1166                 int facility;
1167                 char *name;
1168         }   facTbl[] =
1169         {
1170                 {   LOG_KERN,   "kern"          },
1171                 {   LOG_USER,   "user"          },
1172                 {   LOG_MAIL,   "mail"          },
1173                 {   LOG_DAEMON, "daemon"        },
1174                 {   LOG_AUTH,   "auth"          },
1175                 {   LOG_SYSLOG, "syslog"        },
1176                 {   LOG_LPR,    "lpr"           },
1177                 {   LOG_NEWS,   "news"          },
1178                 {   LOG_UUCP,   "uucp"          },
1179                 {   LOG_LOCAL0, "local0"        },
1180                 {   LOG_LOCAL1, "local1"        },
1181                 {   LOG_LOCAL2, "local2"        },
1182                 {   LOG_LOCAL3, "local3"        },
1183                 {   LOG_LOCAL4, "local4"        },
1184                 {   LOG_LOCAL5, "local5"        },
1185                 {   LOG_LOCAL6, "local6"        },
1186                 {   LOG_LOCAL7, "local7"        },
1187                 {   0,            NULL          }
1188         };
1189         for(i = 0; facTbl[i].name != NULL; i++) {
1190                 if(!strcasecmp(name, facTbl[i].name))
1191                         return facTbl[i].facility;
1192         }
1193         return LOG_DAEMON;
1194 }