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