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 const char markdown_editor_absolutedir[]=MARKDOWNEDITORDIR;
  75
  76 char etc_dir[PATH_MAX];
  77 char static_dir[PATH_MAX];              /* calculated on startup */
  78 char static_local_dir[PATH_MAX];                /* calculated on startup */
  79 char static_icon_dir[PATH_MAX];          /* where should we find our mime icons? */
  80 char  *static_dirs[]={                          /* needs same sort order as the web mapping */
  81         (char*)static_dir,                      /* our templates on disk */
  82         (char*)static_local_dir,                /* user provided templates disk */
  83         (char*)editor_absolut_dir,              /* the editor on disk */
  84         (char*)static_icon_dir,                  /* our icons... */
  85         (char*)markdown_editor_absolutedir
  86 };
  87
  88 int ExitPipe[2];
  89 HashList *GZMimeBlackList = NULL; /* mimetypes which shouldn't be gzip compressed */
  90
  91 void LoadMimeBlacklist(void)
  92 {
  93         StrBuf *MimeBlackLine;
  94         IOBuffer IOB;
  95         eReadState state;
  96
  97         memset(&IOB, 0, sizeof(IOBuffer));
  98         IOB.fd = open(file_etc_mimelist, O_RDONLY);
  99
 100         IOB.Buf = NewStrBuf();
 101         MimeBlackLine = NewStrBuf();
 102         GZMimeBlackList = NewHash(1, NULL);
 103
 104         do
 105         {
 106                 state = StrBufChunkSipLine(MimeBlackLine, &IOB);
 107
 108                 switch (state)
 109                 {
 110                 case eMustReadMore:
 111                         if (StrBuf_read_one_chunk_callback(IOB.fd, 0, &IOB) <= 0)
 112                                 state = eReadFail;
 113                         break;
 114                 case eReadSuccess:
 115                         if ((StrLength(MimeBlackLine) > 1) &&
 116                             (*ChrPtr(MimeBlackLine) != '#'))
 117                         {
 118                                 Put(GZMimeBlackList, SKEY(MimeBlackLine),
 119                                     (void*) 1, reference_free_handler);
 120                         }
 121                         FlushStrBuf(MimeBlackLine);
 122                         break;
 123                 case eReadFail:
 124                         break;
 125                 case eBufferNotEmpty:
 126                         break;
 127                 }
 128         }
 129         while (state != eReadFail);
 130
 131         close(IOB.fd);
 132
 133         FreeStrBuf(&IOB.Buf);
 134         FreeStrBuf(&MimeBlackLine);
 135 }
 136
 137 void CheckGZipCompressionAllowed(const char *MimeType, long MLen)
 138 {
 139         void *v;
 140         wcsession *WCC = WC;
 141
 142         if (WCC->Hdr->HR.gzip_ok)
 143             WCC->Hdr->HR.gzip_ok = GetHash(GZMimeBlackList, MimeType, MLen, &v) == 0;
 144 }
 145
 146 void InitialiseSemaphores(void)
 147 {
 148         int i;
 149
 150         /* Set up a bunch of semaphores to be used for critical sections */
 151         for (i=0; i<MAX_SEMAPHORES; ++i) {
 152                 pthread_mutex_init(&Critters[i], NULL);
 153         }
 154
 155         if (pipe(ExitPipe))
 156         {
 157                 syslog(LOG_WARNING, "Failed to open exit pipe: %d [%s]\n",
 158                        errno,
 159                        strerror(errno));
 160
 161                 exit(-1);
 162         }
 163 }
 164
 165 /*
 166  * Obtain a semaphore lock to begin a critical section.
 167  */
 168 void begin_critical_section(int which_one)
 169 {
 170         pthread_mutex_lock(&Critters[which_one]);
 171 }
 172
 173 /*
 174  * Release a semaphore lock to end a critical section.
 175  */
 176 void end_critical_section(int which_one)
 177 {
 178         pthread_mutex_unlock(&Critters[which_one]);
 179 }
 180
 181
 182 void ShutDownWebcit(void)
 183 {
 184
 185         DeleteHash(&GZMimeBlackList);
 186         free_zone_directory ();
 187         icaltimezone_release_zone_tab ();
 188         icalmemory_free_ring ();
 189         ShutDownLibCitadel ();
 190         shutdown_modules ();
 191 #ifdef HAVE_OPENSSL
 192         if (is_https) {
 193                 shutdown_ssl();
 194         }
 195 #endif
 196 }
 197
 198 /*
 199  * Entry point for worker threads
 200  */
 201 void worker_entry(void)
 202 {
 203         int ssock;
 204         int i = 0;
 205         int fail_this_transaction = 0;
 206         ParsedHttpHdrs Hdr;
 207
 208         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 209         Hdr.HR.eReqType = eGET;
 210         http_new_modules(&Hdr);
 211
 212         do {
 213                 /* Each worker thread blocks on accept() while waiting for something to do. */
 214                 fail_this_transaction = 0;
 215                 ssock = -1;
 216                 errno = EAGAIN;
 217                 do {
 218                         fd_set wset;
 219                         --num_threads_executing;
 220                         FD_ZERO(&wset);
 221                         FD_SET(msock, &wset);
 222                         FD_SET(ExitPipe[1], &wset);
 223
 224                         select(msock + 1, NULL, &wset, NULL, NULL);
 225                         if (time_to_die)
 226                                 break;
 227
 228                         ssock = accept(msock, NULL, 0);
 229                         ++num_threads_executing;
 230                         if (ssock < 0) fail_this_transaction = 1;
 231                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 232
 233                 if ((msock == -1)||(time_to_die))
 234                 {/* ok, we're going down. */
 235                         int shutdown = 0;
 236
 237                         /* The first thread to get here will have to do the cleanup.
 238                          * Make sure it's really just one.
 239                          */
 240                         begin_critical_section(S_SHUTDOWN);
 241                         if (msock == -1)
 242                         {
 243                                 msock = -2;
 244                                 shutdown = 1;
 245                         }
 246                         end_critical_section(S_SHUTDOWN);
 247                         if (shutdown == 1)
 248                         {/* we're the one to cleanup the mess. */
 249                                 http_destroy_modules(&Hdr);
 250                                 syslog(LOG_DEBUG, "I'm master shutdown: tagging sessions to be killed.\n");
 251                                 shutdown_sessions();
 252                                 syslog(LOG_DEBUG, "master shutdown: waiting for others\n");
 253                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 254                                 syslog(LOG_DEBUG, "master shutdown: cleaning up sessions\n");
 255                                 do_housekeeping();
 256                                 syslog(LOG_DEBUG, "master shutdown: cleaning up libical\n");
 257
 258                                 ShutDownWebcit();
 259
 260                                 syslog(LOG_DEBUG, "master shutdown exiting.\n");
 261                                 exit(0);
 262                         }
 263                         break;
 264                 }
 265                 if (ssock < 0 ) continue;
 266
 267                 check_thread_pool_size();
 268
 269                 /* Now do something. */
 270                 if (msock < 0) {
 271                         if (ssock > 0) close (ssock);
 272                         syslog(LOG_DEBUG, "in between.");
 273                         pthread_exit(NULL);
 274                 } else {
 275                         /* Got it? do some real work! */
 276                         /* Set the SO_REUSEADDR socket option */
 277                         i = 1;
 278                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 279
 280                         /* If we are an HTTPS server, go crypto now. */
 281 #ifdef HAVE_OPENSSL
 282                         if (is_https) {
 283                                 if (starttls(ssock) != 0) {
 284                                         fail_this_transaction = 1;
 285                                         close(ssock);
 286                                 }
 287                         }
 288                         else
 289 #endif
 290                         {
 291                                 int fdflags;
 292                                 fdflags = fcntl(ssock, F_GETFL);
 293                                 if (fdflags < 0)
 294                                         syslog(LOG_WARNING, "unable to get server socket flags! %s \n",
 295                                                 strerror(errno));
 296                                 fdflags = fdflags | O_NONBLOCK;
 297                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 298                                         syslog(LOG_WARNING, "unable to set server socket nonblocking flags! %s \n",
 299                                                 strerror(errno));
 300                         }
 301
 302                         if (fail_this_transaction == 0) {
 303                                 Hdr.http_sock = ssock;
 304
 305                                 /* Perform an HTTP transaction... */
 306                                 context_loop(&Hdr);
 307
 308                                 /* Shut down SSL/TLS if required... */
 309 #ifdef HAVE_OPENSSL
 310                                 if (is_https) {
 311                                         endtls();
 312                                 }
 313 #endif
 314
 315                                 /* ...and close the socket. */
 316                                 if (Hdr.http_sock > 0) {
 317                                         lingering_close(ssock);
 318                                 }
 319                                 http_detach_modules(&Hdr);
 320
 321                         }
 322
 323                 }
 324
 325         } while (!time_to_die);
 326
 327         http_destroy_modules(&Hdr);
 328         syslog(LOG_DEBUG, "Thread exiting.\n");
 329         pthread_exit(NULL);
 330 }
 331
 332
 333 /*
 334  * Shut us down the regular way.
 335  * signum is the signal we want to forward
 336  */
 337 pid_t current_child;
 338 void graceful_shutdown_watcher(int signum) {
 339         syslog(LOG_INFO, "Watcher thread exiting.\n");
 340         write(ExitPipe[0], HKEY("                              "));
 341         kill(current_child, signum);
 342         if (signum != SIGHUP)
 343                 exit(0);
 344 }
 345
 346
 347 /*
 348  * Shut us down the regular way.
 349  * signum is the signal we want to forward
 350  */
 351 pid_t current_child;
 352 void graceful_shutdown(int signum) {
 353         FILE *FD;
 354         int fd;
 355
 356         syslog(LOG_INFO, "WebCit is being shut down on signal %d.\n", signum);
 357         fd = msock;
 358         msock = -1;
 359         time_to_die = 1;
 360         FD=fdopen(fd, "a+");
 361         fflush (FD);
 362         fclose (FD);
 363         close(fd);
 364         write(ExitPipe[0], HKEY("                              "));
 365 }
 366
 367
 368 /*
 369  * Start running as a daemon.
 370  */
 371 void start_daemon(char *pid_file)
 372 {
 373         int status = 0;
 374         pid_t child = 0;
 375         FILE *fp;
 376         int do_restart = 0;
 377
 378         current_child = 0;
 379
 380         /* Close stdin/stdout/stderr and replace them with /dev/null.
 381          * We don't just call close() because we don't want these fd's
 382          * to be reused for other files.
 383          */
 384         chdir("/");
 385
 386         signal(SIGHUP, SIG_IGN);
 387         signal(SIGINT, SIG_IGN);
 388         signal(SIGQUIT, SIG_IGN);
 389
 390         child = fork();
 391         if (child != 0) {
 392                 exit(0);
 393         }
 394
 395         setsid();
 396         umask(0);
 397         freopen("/dev/null", "r", stdin);
 398         freopen("/dev/null", "w", stdout);
 399         freopen("/dev/null", "w", stderr);
 400         signal(SIGTERM, graceful_shutdown_watcher);
 401         signal(SIGHUP, graceful_shutdown_watcher);
 402
 403         do {
 404                 current_child = fork();
 405
 406
 407                 if (current_child < 0) {
 408                         perror("fork");
 409                         ShutDownLibCitadel ();
 410                         exit(errno);
 411                 }
 412
 413                 else if (current_child == 0) {  /* child process */
 414                         signal(SIGHUP, graceful_shutdown);
 415
 416                         return; /* continue starting webcit. */
 417                 }
 418                 else { /* watcher process */
 419                         if (pid_file) {
 420                                 fp = fopen(pid_file, "w");
 421                                 if (fp != NULL) {
 422                                         fprintf(fp, "%d\n", getpid());
 423                                         fclose(fp);
 424                                 }
 425                         }
 426                         waitpid(current_child, &status, 0);
 427                 }
 428
 429                 do_restart = 0;
 430
 431                 /* Did the main process exit with an actual exit code? */
 432                 if (WIFEXITED(status)) {
 433
 434                         /* Exit code 0 means the watcher should exit */
 435                         if (WEXITSTATUS(status) == 0) {
 436                                 do_restart = 0;
 437                         }
 438
 439                         /* Exit code 101-109 means the watcher should exit */
 440                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 441                                 do_restart = 0;
 442                         }
 443
 444                         /* Any other exit code means we should restart. */
 445                         else {
 446                                 do_restart = 1;
 447                         }
 448                 }
 449
 450                 /* Any other type of termination (signals, etc.) should also restart. */
 451                 else {
 452                         do_restart = 1;
 453                 }
 454
 455         } while (do_restart);
 456
 457         if (pid_file) {
 458                 unlink(pid_file);
 459         }
 460         ShutDownLibCitadel ();
 461         exit(WEXITSTATUS(status));
 462 }
 463
 464
 465 /*
 466  * Spawn an additional worker thread into the pool.
 467  */
 468 void spawn_another_worker_thread()
 469 {
 470         pthread_t SessThread;   /* Thread descriptor */
 471         pthread_attr_t attr;    /* Thread attributes */
 472         int ret;
 473
 474         ++num_threads_existing;
 475         ++num_threads_executing;
 476
 477         /* set attributes for the new thread */
 478         pthread_attr_init(&attr);
 479         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 480
 481         /*
 482          * Our per-thread stacks need to be bigger than the default size,
 483          * otherwise the MIME parser crashes on FreeBSD.
 484          */
 485         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 486                 syslog(LOG_WARNING, "pthread_attr_setstacksize: %s\n", strerror(ret));
 487                 pthread_attr_destroy(&attr);
 488         }
 489
 490         /* now create the thread */
 491         if (pthread_create(&SessThread, &attr, (void *(*)(void *)) worker_entry, NULL) != 0) {
 492                 syslog(LOG_WARNING, "Can't create thread: %s\n", strerror(errno));
 493         }
 494
 495         /* free up the attributes */
 496         pthread_attr_destroy(&attr);
 497 }
 498
 499
 500 void
 501 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 502 {
 503         char dirbuffer[PATH_MAX]="";
 504         /* calculate all our path on a central place */
 505     /* where to keep our config */
 506
 507 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 508         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 509                          (home&!relh)?webcitdir:basedir, \
 510              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 511              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 512                          relhome, \
 513              (relhome[0]!='\0')?"/":"",\
 514                          dirbuffer,\
 515                          (dirbuffer[0]!='\0')?"/":"");
 516         basedir=RUNDIR;
 517         COMPUTE_DIRECTORY(socket_dir);
 518         basedir=WWWDIR "/static";
 519         COMPUTE_DIRECTORY(static_dir);
 520         basedir=WWWDIR "/static/icons";
 521         COMPUTE_DIRECTORY(static_icon_dir);
 522         basedir=WWWDIR "/static.local";
 523         COMPUTE_DIRECTORY(static_local_dir);
 524         StripSlashes(static_dir, 1);
 525         StripSlashes(static_icon_dir, 1);
 526         StripSlashes(static_local_dir, 1);
 527
 528         snprintf(file_crpt_file_key,
 529                  sizeof file_crpt_file_key,
 530                  "%s/citadel.key",
 531                  ctdl_key_dir);
 532         snprintf(file_crpt_file_csr,
 533                  sizeof file_crpt_file_csr,
 534                  "%s/citadel.csr",
 535                  ctdl_key_dir);
 536         snprintf(file_crpt_file_cer,
 537                  sizeof file_crpt_file_cer,
 538                  "%s/citadel.cer",
 539                  ctdl_key_dir);
 540
 541
 542         basedir=ETCDIR;
 543         COMPUTE_DIRECTORY(etc_dir);
 544         StripSlashes(etc_dir, 1);
 545         snprintf(file_etc_mimelist,
 546                  sizeof file_etc_mimelist,
 547                  "%s/nogz-mimetypes.txt",
 548                  etc_dir);
 549
 550         /* we should go somewhere we can leave our coredump, if enabled... */
 551         syslog(LOG_INFO, "Changing directory to %s\n", socket_dir);
 552         if (chdir(webcitdir) != 0) {
 553                 perror("chdir");
 554         }
 555 }
 556
 557 void drop_root(uid_t UID)
 558 {
 559         struct passwd pw, *pwp = NULL;
 560 #ifdef HAVE_GETPWUID_R
 561         char pwbuf[SIZ];
 562 #endif
 563
 564         /*
 565          * Now that we've bound the sockets, change to the Citadel user id and its
 566          * corresponding group ids
 567          */
 568         if (UID != -1) {
 569
 570 #ifdef HAVE_GETPWUID_R
 571 #ifdef SOLARIS_GETPWUID
 572                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 573 #else /* SOLARIS_GETPWUID */
 574                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 575 #endif /* SOLARIS_GETPWUID */
 576 #else /* HAVE_GETPWUID_R */
 577                 pwp = NULL;
 578 #endif /* HAVE_GETPWUID_R */
 579
 580                 if (pwp == NULL)
 581                         syslog(LOG_CRIT, "WARNING: getpwuid(%d): %s\n"
 582                                 "Group IDs will be incorrect.\n", UID,
 583                                 strerror(errno));
 584                 else {
 585                         initgroups(pw.pw_name, pw.pw_gid);
 586                         if (setgid(pw.pw_gid))
 587                                 syslog(LOG_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 588                                         strerror(errno));
 589                 }
 590                 syslog(LOG_INFO, "Changing uid to %ld\n", (long)UID);
 591                 if (setuid(UID) != 0) {
 592                         syslog(LOG_CRIT, "setuid() failed: %s\n", strerror(errno));
 593                 }
 594 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 595                 prctl(PR_SET_DUMPABLE, 1);
 596 #endif
 597         }
 598 }
 599
 600
 601 /*
 602  * print the actual stack frame.
 603  */
 604 void wc_backtrace(long LogLevel)
 605 {
 606 #ifdef HAVE_BACKTRACE
 607         void *stack_frames[50];
 608         size_t size, i;
 609         char **strings;
 610
 611
 612         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 613         strings = backtrace_symbols(stack_frames, size);
 614         for (i = 0; i < size; i++) {
 615                 if (strings != NULL)
 616                         syslog(LogLevel, "%s\n", strings[i]);
 617                 else
 618                         syslog(LogLevel, "%p\n", stack_frames[i]);
 619         }
 620         free(strings);
 621 #endif
 622 }