webcit/sysdep.c

   1 /*
   2  * WebCit "system dependent" code.
   3  *
   4  * Copyright (c) 1996-2012 by the citadel.org team
   5  *
   6  * This program is open source software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 3.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include "sysdep.h"
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <fcntl.h>
  20 #include <ctype.h>
  21 #include <signal.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <sys/wait.h>
  25 #include <sys/socket.h>
  26 #include <syslog.h>
  27 #include <sys/syslog.h>
  28 #include <time.h>
  29 #include <limits.h>
  30 #include <sys/resource.h>
  31 #include <netinet/in.h>
  32 #include <netinet/tcp.h>
  33 #include <arpa/inet.h>
  34 #include <netdb.h>
  35 #include <sys/un.h>
  36 #include <string.h>
  37 #include <pwd.h>
  38 #include <errno.h>
  39 #include <stdarg.h>
  40 #include <grp.h>
  41 #ifdef HAVE_PTHREAD_H
  42 #include <pthread.h>
  43 #endif
  44 #include "webcit.h"
  45 #include "sysdep.h"
  46
  47 #ifdef HAVE_SYS_SELECT_H
  48 #include <sys/select.h>
  49 #endif
  50
  51 #include "webserver.h"
  52 #include "modules_init.h"
  53 #if HAVE_BACKTRACE
  54 #include <execinfo.h>
  55 #endif
  56
  57 pthread_mutex_t Critters[MAX_SEMAPHORES];       /* Things needing locking */
  58 pthread_key_t MyConKey;                         /* TSD key for MyContext() */
  59 pthread_key_t MyReq;                            /* TSD key for MyReq() */
  60 int msock;                      /* master listening socket */
  61 int time_to_die = 0;            /* Nonzero if server is shutting down */
  62
  63 extern void *context_loop(ParsedHttpHdrs *Hdr);
  64 extern void *housekeeping_loop(void);
  65 extern void do_housekeeping(void);
  66
  67 char ctdl_key_dir[PATH_MAX]=SSL_DIR;
  68 char file_crpt_file_key[PATH_MAX]="";
  69 char file_crpt_file_csr[PATH_MAX]="";
  70 char file_crpt_file_cer[PATH_MAX]="";
  71 char file_etc_mimelist[PATH_MAX]="";
  72
  73 const char editor_absolut_dir[PATH_MAX]=EDITORDIR;      /* nailed to what configure gives us. */
  74
  75 char etc_dir[PATH_MAX];
  76 char static_dir[PATH_MAX];              /* calculated on startup */
  77 char static_local_dir[PATH_MAX];                /* calculated on startup */
  78 char static_icon_dir[PATH_MAX];          /* where should we find our mime icons? */
  79 char  *static_dirs[]={                          /* needs same sort order as the web mapping */
  80         (char*)static_dir,                      /* our templates on disk */
  81         (char*)static_local_dir,                /* user provided templates disk */
  82         (char*)editor_absolut_dir,              /* the editor on disk */
  83         (char*)static_icon_dir                  /* our icons... */
  84 };
  85
  86 int ExitPipe[2];
  87 HashList *GZMimeBlackList = NULL; /* mimetypes which shouldn't be gzip compressed */
  88
  89 void LoadMimeBlacklist(void)
  90 {
  91         StrBuf *MimeBlackLine;
  92         IOBuffer IOB;
  93         eReadState state;
  94
  95         memset(&IOB, 0, sizeof(IOBuffer));
  96         IOB.fd = open(file_etc_mimelist, O_RDONLY);
  97
  98         IOB.Buf = NewStrBuf();
  99         MimeBlackLine = NewStrBuf();
 100         GZMimeBlackList = NewHash(1, NULL);
 101
 102         do
 103         {
 104                 state = StrBufChunkSipLine(MimeBlackLine, &IOB);
 105
 106                 switch (state)
 107                 {
 108                 case eMustReadMore:
 109                         if (StrBuf_read_one_chunk_callback(IOB.fd, 0, &IOB) <= 0)
 110                                 state = eReadFail;
 111                         break;
 112                 case eReadSuccess:
 113                         if ((StrLength(MimeBlackLine) > 1) &&
 114                             (*ChrPtr(MimeBlackLine) != '#'))
 115                         {
 116                                 Put(GZMimeBlackList, SKEY(MimeBlackLine),
 117                                     (void*) 1, reference_free_handler);
 118                         }
 119                         FlushStrBuf(MimeBlackLine);
 120                         break;
 121                 case eReadFail:
 122                         break;
 123                 case eBufferNotEmpty:
 124                         break;
 125                 }
 126         }
 127         while (state != eReadFail);
 128
 129         close(IOB.fd);
 130
 131         FreeStrBuf(&IOB.Buf);
 132         FreeStrBuf(&MimeBlackLine);
 133 }
 134
 135 void CheckGZipCompressionAllowed(const char *MimeType, long MLen)
 136 {
 137         void *v;
 138         wcsession *WCC = WC;
 139
 140         if (WCC->Hdr->HR.gzip_ok)
 141             WCC->Hdr->HR.gzip_ok = GetHash(GZMimeBlackList, MimeType, MLen, &v) == 0;
 142 }
 143
 144 void InitialiseSemaphores(void)
 145 {
 146         int i;
 147
 148         /* Set up a bunch of semaphores to be used for critical sections */
 149         for (i=0; i<MAX_SEMAPHORES; ++i) {
 150                 pthread_mutex_init(&Critters[i], NULL);
 151         }
 152
 153         if (pipe(ExitPipe))
 154         {
 155                 syslog(LOG_WARNING, "Failed to open exit pipe: %d [%s]\n",
 156                        errno,
 157                        strerror(errno));
 158
 159                 exit(-1);
 160         }
 161 }
 162
 163 /*
 164  * Obtain a semaphore lock to begin a critical section.
 165  */
 166 void begin_critical_section(int which_one)
 167 {
 168         pthread_mutex_lock(&Critters[which_one]);
 169 }
 170
 171 /*
 172  * Release a semaphore lock to end a critical section.
 173  */
 174 void end_critical_section(int which_one)
 175 {
 176         pthread_mutex_unlock(&Critters[which_one]);
 177 }
 178
 179
 180 void ShutDownWebcit(void)
 181 {
 182
 183         DeleteHash(&GZMimeBlackList);
 184         free_zone_directory ();
 185         icaltimezone_release_zone_tab ();
 186         icalmemory_free_ring ();
 187         ShutDownLibCitadel ();
 188         shutdown_modules ();
 189 #ifdef HAVE_OPENSSL
 190         if (is_https) {
 191                 shutdown_ssl();
 192         }
 193 #endif
 194 }
 195
 196 /*
 197  * Entry point for worker threads
 198  */
 199 void worker_entry(void)
 200 {
 201         int ssock;
 202         int i = 0;
 203         int fail_this_transaction = 0;
 204         ParsedHttpHdrs Hdr;
 205
 206         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 207         Hdr.HR.eReqType = eGET;
 208         http_new_modules(&Hdr);
 209
 210         do {
 211                 /* Each worker thread blocks on accept() while waiting for something to do. */
 212                 fail_this_transaction = 0;
 213                 ssock = -1;
 214                 errno = EAGAIN;
 215                 do {
 216                         fd_set wset;
 217                         --num_threads_executing;
 218                         FD_ZERO(&wset);
 219                         FD_SET(msock, &wset);
 220                         FD_SET(ExitPipe[1], &wset);
 221
 222                         select(msock + 1, NULL, &wset, NULL, NULL);
 223                         if (time_to_die)
 224                                 break;
 225
 226                         ssock = accept(msock, NULL, 0);
 227                         ++num_threads_executing;
 228                         if (ssock < 0) fail_this_transaction = 1;
 229                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 230
 231                 if ((msock == -1)||(time_to_die))
 232                 {/* ok, we're going down. */
 233                         int shutdown = 0;
 234
 235                         /* The first thread to get here will have to do the cleanup.
 236                          * Make sure it's really just one.
 237                          */
 238                         begin_critical_section(S_SHUTDOWN);
 239                         if (msock == -1)
 240                         {
 241                                 msock = -2;
 242                                 shutdown = 1;
 243                         }
 244                         end_critical_section(S_SHUTDOWN);
 245                         if (shutdown == 1)
 246                         {/* we're the one to cleanup the mess. */
 247                                 http_destroy_modules(&Hdr);
 248                                 syslog(LOG_DEBUG, "I'm master shutdown: tagging sessions to be killed.\n");
 249                                 shutdown_sessions();
 250                                 syslog(LOG_DEBUG, "master shutdown: waiting for others\n");
 251                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 252                                 syslog(LOG_DEBUG, "master shutdown: cleaning up sessions\n");
 253                                 do_housekeeping();
 254                                 syslog(LOG_DEBUG, "master shutdown: cleaning up libical\n");
 255
 256                                 ShutDownWebcit();
 257
 258                                 syslog(LOG_DEBUG, "master shutdown exiting.\n");
 259                                 exit(0);
 260                         }
 261                         break;
 262                 }
 263                 if (ssock < 0 ) continue;
 264
 265                 check_thread_pool_size();
 266
 267                 /* Now do something. */
 268                 if (msock < 0) {
 269                         if (ssock > 0) close (ssock);
 270                         syslog(LOG_DEBUG, "in between.");
 271                         pthread_exit(NULL);
 272                 } else {
 273                         /* Got it? do some real work! */
 274                         /* Set the SO_REUSEADDR socket option */
 275                         i = 1;
 276                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 277
 278                         /* If we are an HTTPS server, go crypto now. */
 279 #ifdef HAVE_OPENSSL
 280                         if (is_https) {
 281                                 if (starttls(ssock) != 0) {
 282                                         fail_this_transaction = 1;
 283                                         close(ssock);
 284                                 }
 285                         }
 286                         else
 287 #endif
 288                         {
 289                                 int fdflags;
 290                                 fdflags = fcntl(ssock, F_GETFL);
 291                                 if (fdflags < 0)
 292                                         syslog(LOG_WARNING, "unable to get server socket flags! %s \n",
 293                                                 strerror(errno));
 294                                 fdflags = fdflags | O_NONBLOCK;
 295                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 296                                         syslog(LOG_WARNING, "unable to set server socket nonblocking flags! %s \n",
 297                                                 strerror(errno));
 298                         }
 299
 300                         if (fail_this_transaction == 0) {
 301                                 Hdr.http_sock = ssock;
 302
 303                                 /* Perform an HTTP transaction... */
 304                                 context_loop(&Hdr);
 305
 306                                 /* Shut down SSL/TLS if required... */
 307 #ifdef HAVE_OPENSSL
 308                                 if (is_https) {
 309                                         endtls();
 310                                 }
 311 #endif
 312
 313                                 /* ...and close the socket. */
 314                                 if (Hdr.http_sock > 0) {
 315                                         lingering_close(ssock);
 316                                 }
 317                                 http_detach_modules(&Hdr);
 318
 319                         }
 320
 321                 }
 322
 323         } while (!time_to_die);
 324
 325         http_destroy_modules(&Hdr);
 326         syslog(LOG_DEBUG, "Thread exiting.\n");
 327         pthread_exit(NULL);
 328 }
 329
 330
 331 /*
 332  * Shut us down the regular way.
 333  * signum is the signal we want to forward
 334  */
 335 pid_t current_child;
 336 void graceful_shutdown_watcher(int signum) {
 337         syslog(LOG_INFO, "Watcher thread exiting.\n");
 338         write(ExitPipe[0], HKEY("                              "));
 339         kill(current_child, signum);
 340         if (signum != SIGHUP)
 341                 exit(0);
 342 }
 343
 344
 345 /*
 346  * Shut us down the regular way.
 347  * signum is the signal we want to forward
 348  */
 349 pid_t current_child;
 350 void graceful_shutdown(int signum) {
 351         FILE *FD;
 352         int fd;
 353
 354         syslog(LOG_INFO, "WebCit is being shut down on signal %d.\n", signum);
 355         fd = msock;
 356         msock = -1;
 357         time_to_die = 1;
 358         FD=fdopen(fd, "a+");
 359         fflush (FD);
 360         fclose (FD);
 361         close(fd);
 362         write(ExitPipe[0], HKEY("                              "));
 363 }
 364
 365
 366 /*
 367  * Start running as a daemon.
 368  */
 369 void start_daemon(char *pid_file)
 370 {
 371         int status = 0;
 372         pid_t child = 0;
 373         FILE *fp;
 374         int do_restart = 0;
 375
 376         current_child = 0;
 377
 378         /* Close stdin/stdout/stderr and replace them with /dev/null.
 379          * We don't just call close() because we don't want these fd's
 380          * to be reused for other files.
 381          */
 382         chdir("/");
 383
 384         signal(SIGHUP, SIG_IGN);
 385         signal(SIGINT, SIG_IGN);
 386         signal(SIGQUIT, SIG_IGN);
 387
 388         child = fork();
 389         if (child != 0) {
 390                 exit(0);
 391         }
 392
 393         setsid();
 394         umask(0);
 395         freopen("/dev/null", "r", stdin);
 396         freopen("/dev/null", "w", stdout);
 397         freopen("/dev/null", "w", stderr);
 398         signal(SIGTERM, graceful_shutdown_watcher);
 399         signal(SIGHUP, graceful_shutdown_watcher);
 400
 401         do {
 402                 current_child = fork();
 403
 404
 405                 if (current_child < 0) {
 406                         perror("fork");
 407                         ShutDownLibCitadel ();
 408                         exit(errno);
 409                 }
 410
 411                 else if (current_child == 0) {  /* child process */
 412                         signal(SIGHUP, graceful_shutdown);
 413
 414                         return; /* continue starting webcit. */
 415                 }
 416                 else { /* watcher process */
 417                         if (pid_file) {
 418                                 fp = fopen(pid_file, "w");
 419                                 if (fp != NULL) {
 420                                         fprintf(fp, "%d\n", getpid());
 421                                         fclose(fp);
 422                                 }
 423                         }
 424                         waitpid(current_child, &status, 0);
 425                 }
 426
 427                 do_restart = 0;
 428
 429                 /* Did the main process exit with an actual exit code? */
 430                 if (WIFEXITED(status)) {
 431
 432                         /* Exit code 0 means the watcher should exit */
 433                         if (WEXITSTATUS(status) == 0) {
 434                                 do_restart = 0;
 435                         }
 436
 437                         /* Exit code 101-109 means the watcher should exit */
 438                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 439                                 do_restart = 0;
 440                         }
 441
 442                         /* Any other exit code means we should restart. */
 443                         else {
 444                                 do_restart = 1;
 445                         }
 446                 }
 447
 448                 /* Any other type of termination (signals, etc.) should also restart. */
 449                 else {
 450                         do_restart = 1;
 451                 }
 452
 453         } while (do_restart);
 454
 455         if (pid_file) {
 456                 unlink(pid_file);
 457         }
 458         ShutDownLibCitadel ();
 459         exit(WEXITSTATUS(status));
 460 }
 461
 462
 463 /*
 464  * Spawn an additional worker thread into the pool.
 465  */
 466 void spawn_another_worker_thread()
 467 {
 468         pthread_t SessThread;   /* Thread descriptor */
 469         pthread_attr_t attr;    /* Thread attributes */
 470         int ret;
 471
 472         ++num_threads_existing;
 473         ++num_threads_executing;
 474
 475         /* set attributes for the new thread */
 476         pthread_attr_init(&attr);
 477         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 478
 479         /*
 480          * Our per-thread stacks need to be bigger than the default size,
 481          * otherwise the MIME parser crashes on FreeBSD.
 482          */
 483         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 484                 syslog(LOG_WARNING, "pthread_attr_setstacksize: %s\n", strerror(ret));
 485                 pthread_attr_destroy(&attr);
 486         }
 487
 488         /* now create the thread */
 489         if (pthread_create(&SessThread, &attr, (void *(*)(void *)) worker_entry, NULL) != 0) {
 490                 syslog(LOG_WARNING, "Can't create thread: %s\n", strerror(errno));
 491         }
 492
 493         /* free up the attributes */
 494         pthread_attr_destroy(&attr);
 495 }
 496
 497
 498 void
 499 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 500 {
 501         char dirbuffer[PATH_MAX]="";
 502         /* calculate all our path on a central place */
 503     /* where to keep our config */
 504
 505 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 506         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 507                          (home&!relh)?webcitdir:basedir, \
 508              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 509              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 510                          relhome, \
 511              (relhome[0]!='\0')?"/":"",\
 512                          dirbuffer,\
 513                          (dirbuffer[0]!='\0')?"/":"");
 514         basedir=RUNDIR;
 515         COMPUTE_DIRECTORY(socket_dir);
 516         basedir=WWWDIR "/static";
 517         COMPUTE_DIRECTORY(static_dir);
 518         basedir=WWWDIR "/static/icons";
 519         COMPUTE_DIRECTORY(static_icon_dir);
 520         basedir=WWWDIR "/static.local";
 521         COMPUTE_DIRECTORY(static_local_dir);
 522         StripSlashes(static_dir, 1);
 523         StripSlashes(static_icon_dir, 1);
 524         StripSlashes(static_local_dir, 1);
 525
 526         snprintf(file_crpt_file_key,
 527                  sizeof file_crpt_file_key,
 528                  "%s/citadel.key",
 529                  ctdl_key_dir);
 530         snprintf(file_crpt_file_csr,
 531                  sizeof file_crpt_file_csr,
 532                  "%s/citadel.csr",
 533                  ctdl_key_dir);
 534         snprintf(file_crpt_file_cer,
 535                  sizeof file_crpt_file_cer,
 536                  "%s/citadel.cer",
 537                  ctdl_key_dir);
 538
 539
 540         basedir=ETCDIR;
 541         COMPUTE_DIRECTORY(etc_dir);
 542         StripSlashes(etc_dir, 1);
 543         snprintf(file_etc_mimelist,
 544                  sizeof file_etc_mimelist,
 545                  "%s/nogz-mimetypes.txt",
 546                  etc_dir);
 547
 548         /* we should go somewhere we can leave our coredump, if enabled... */
 549         syslog(LOG_INFO, "Changing directory to %s\n", socket_dir);
 550         if (chdir(webcitdir) != 0) {
 551                 perror("chdir");
 552         }
 553 }
 554
 555 void drop_root(uid_t UID)
 556 {
 557         struct passwd pw, *pwp = NULL;
 558 #ifdef HAVE_GETPWUID_R
 559         char pwbuf[SIZ];
 560 #endif
 561
 562         /*
 563          * Now that we've bound the sockets, change to the Citadel user id and its
 564          * corresponding group ids
 565          */
 566         if (UID != -1) {
 567
 568 #ifdef HAVE_GETPWUID_R
 569 #ifdef SOLARIS_GETPWUID
 570                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 571 #else /* SOLARIS_GETPWUID */
 572                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 573 #endif /* SOLARIS_GETPWUID */
 574 #else /* HAVE_GETPWUID_R */
 575                 pwp = NULL;
 576 #endif /* HAVE_GETPWUID_R */
 577
 578                 if (pwp == NULL)
 579                         syslog(LOG_CRIT, "WARNING: getpwuid(%d): %s\n"
 580                                 "Group IDs will be incorrect.\n", UID,
 581                                 strerror(errno));
 582                 else {
 583                         initgroups(pw.pw_name, pw.pw_gid);
 584                         if (setgid(pw.pw_gid))
 585                                 syslog(LOG_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 586                                         strerror(errno));
 587                 }
 588                 syslog(LOG_INFO, "Changing uid to %ld\n", (long)UID);
 589                 if (setuid(UID) != 0) {
 590                         syslog(LOG_CRIT, "setuid() failed: %s\n", strerror(errno));
 591                 }
 592 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 593                 prctl(PR_SET_DUMPABLE, 1);
 594 #endif
 595         }
 596 }
 597
 598
 599 /*
 600  * print the actual stack frame.
 601  */
 602 void wc_backtrace(long LogLevel)
 603 {
 604 #ifdef HAVE_BACKTRACE
 605         void *stack_frames[50];
 606         size_t size, i;
 607         char **strings;
 608
 609
 610         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 611         strings = backtrace_symbols(stack_frames, size);
 612         for (i = 0; i < size; i++) {
 613                 if (strings != NULL)
 614                         syslog(LogLevel, "%s\n", strings[i]);
 615                 else
 616                         syslog(LogLevel, "%p\n", stack_frames[i]);
 617         }
 618         free(strings);
 619 #endif
 620 }