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
  29 #if TIME_WITH_SYS_TIME
  30 # include <sys/time.h>
  31 # include <time.h>
  32 #else
  33 # if HAVE_SYS_TIME_H
  34 #  include <sys/time.h>
  35 # else
  36 #  include <time.h>
  37 # endif
  38 #endif
  39
  40 #include <limits.h>
  41 #include <sys/resource.h>
  42 #include <netinet/in.h>
  43 #include <netinet/tcp.h>
  44 #include <arpa/inet.h>
  45 #include <netdb.h>
  46 #include <sys/un.h>
  47 #include <string.h>
  48 #include <pwd.h>
  49 #include <errno.h>
  50 #include <stdarg.h>
  51 #include <grp.h>
  52 #ifdef HAVE_PTHREAD_H
  53 #include <pthread.h>
  54 #endif
  55 #include "webcit.h"
  56 #include "sysdep.h"
  57
  58 #ifdef HAVE_SYS_SELECT_H
  59 #include <sys/select.h>
  60 #endif
  61
  62 #include "webserver.h"
  63 #include "modules_init.h"
  64 #if HAVE_BACKTRACE
  65 #include <execinfo.h>
  66 #endif
  67
  68 pthread_mutex_t Critters[MAX_SEMAPHORES];       /* Things needing locking */
  69 pthread_key_t MyConKey;                         /* TSD key for MyContext() */
  70 pthread_key_t MyReq;                            /* TSD key for MyReq() */
  71 int msock;                      /* master listening socket */
  72 int time_to_die = 0;            /* Nonzero if server is shutting down */
  73
  74 extern void *context_loop(ParsedHttpHdrs *Hdr);
  75 extern void *housekeeping_loop(void);
  76 extern void do_housekeeping(void);
  77
  78 char ctdl_key_dir[PATH_MAX]=SSL_DIR;
  79 char file_crpt_file_key[PATH_MAX]="";
  80 char file_crpt_file_csr[PATH_MAX]="";
  81 char file_crpt_file_cer[PATH_MAX]="";
  82 char file_etc_mimelist[PATH_MAX]="";
  83
  84 const char editor_absolut_dir[PATH_MAX]=EDITORDIR;      /* nailed to what configure gives us. */
  85 const char markdown_editor_absolutedir[]=MARKDOWNEDITORDIR;
  86
  87 char etc_dir[PATH_MAX];
  88 char static_dir[PATH_MAX];              /* calculated on startup */
  89 char static_local_dir[PATH_MAX];                /* calculated on startup */
  90 char static_icon_dir[PATH_MAX];          /* where should we find our mime icons? */
  91 char  *static_dirs[]={                          /* needs same sort order as the web mapping */
  92         (char*)static_dir,                      /* our templates on disk */
  93         (char*)static_local_dir,                /* user provided templates disk */
  94         (char*)editor_absolut_dir,              /* the editor on disk */
  95         (char*)static_icon_dir,                  /* our icons... */
  96         (char*)markdown_editor_absolutedir
  97 };
  98
  99 int ExitPipe[2];
 100 HashList *GZMimeBlackList = NULL; /* mimetypes which shouldn't be gzip compressed */
 101
 102 void LoadMimeBlacklist(void)
 103 {
 104         StrBuf *MimeBlackLine;
 105         IOBuffer IOB;
 106         eReadState state;
 107
 108         memset(&IOB, 0, sizeof(IOBuffer));
 109         IOB.fd = open(file_etc_mimelist, O_RDONLY);
 110
 111         IOB.Buf = NewStrBuf();
 112         MimeBlackLine = NewStrBuf();
 113         GZMimeBlackList = NewHash(1, NULL);
 114
 115         do
 116         {
 117                 state = StrBufChunkSipLine(MimeBlackLine, &IOB);
 118
 119                 switch (state)
 120                 {
 121                 case eMustReadMore:
 122                         if (StrBuf_read_one_chunk_callback(IOB.fd, 0, &IOB) <= 0)
 123                                 state = eReadFail;
 124                         break;
 125                 case eReadSuccess:
 126                         if ((StrLength(MimeBlackLine) > 1) &&
 127                             (*ChrPtr(MimeBlackLine) != '#'))
 128                         {
 129                                 Put(GZMimeBlackList, SKEY(MimeBlackLine),
 130                                     (void*) 1, reference_free_handler);
 131                         }
 132                         FlushStrBuf(MimeBlackLine);
 133                         break;
 134                 case eReadFail:
 135                         break;
 136                 case eBufferNotEmpty:
 137                         break;
 138                 }
 139         }
 140         while (state != eReadFail);
 141
 142         close(IOB.fd);
 143
 144         FreeStrBuf(&IOB.Buf);
 145         FreeStrBuf(&MimeBlackLine);
 146 }
 147
 148 void CheckGZipCompressionAllowed(const char *MimeType, long MLen)
 149 {
 150         void *v;
 151         wcsession *WCC = WC;
 152
 153         if (WCC->Hdr->HR.gzip_ok)
 154             WCC->Hdr->HR.gzip_ok = GetHash(GZMimeBlackList, MimeType, MLen, &v) == 0;
 155 }
 156
 157 void InitialiseSemaphores(void)
 158 {
 159         int i;
 160
 161         /* Set up a bunch of semaphores to be used for critical sections */
 162         for (i=0; i<MAX_SEMAPHORES; ++i) {
 163                 pthread_mutex_init(&Critters[i], NULL);
 164         }
 165
 166         if (pipe(ExitPipe))
 167         {
 168                 syslog(LOG_WARNING, "Failed to open exit pipe: %d [%s]\n",
 169                        errno,
 170                        strerror(errno));
 171
 172                 exit(-1);
 173         }
 174 }
 175
 176 /*
 177  * Obtain a semaphore lock to begin a critical section.
 178  */
 179 void begin_critical_section(int which_one)
 180 {
 181         pthread_mutex_lock(&Critters[which_one]);
 182 }
 183
 184 /*
 185  * Release a semaphore lock to end a critical section.
 186  */
 187 void end_critical_section(int which_one)
 188 {
 189         pthread_mutex_unlock(&Critters[which_one]);
 190 }
 191
 192
 193 void ShutDownWebcit(void)
 194 {
 195         free_zone_directory ();
 196         icaltimezone_release_zone_tab ();
 197         icalmemory_free_ring ();
 198         ShutDownLibCitadel ();
 199         shutdown_modules ();
 200 #ifdef HAVE_OPENSSL
 201         if (is_https) {
 202                 shutdown_ssl();
 203         }
 204 #endif
 205 }
 206
 207 /*
 208  * Entry point for worker threads
 209  */
 210 void worker_entry(void)
 211 {
 212         int ssock;
 213         int i = 0;
 214         int fail_this_transaction = 0;
 215         ParsedHttpHdrs Hdr;
 216
 217         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 218         Hdr.HR.eReqType = eGET;
 219         http_new_modules(&Hdr);
 220
 221         do {
 222                 /* Each worker thread blocks on accept() while waiting for something to do. */
 223                 fail_this_transaction = 0;
 224                 ssock = -1;
 225                 errno = EAGAIN;
 226                 do {
 227                         fd_set wset;
 228                         --num_threads_executing;
 229                         FD_ZERO(&wset);
 230                         FD_SET(msock, &wset);
 231                         FD_SET(ExitPipe[1], &wset);
 232
 233                         select(msock + 1, NULL, &wset, NULL, NULL);
 234                         if (time_to_die)
 235                                 break;
 236
 237                         ssock = accept(msock, NULL, 0);
 238                         ++num_threads_executing;
 239                         if (ssock < 0) fail_this_transaction = 1;
 240                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 241
 242                 if ((msock == -1)||(time_to_die))
 243                 {/* ok, we're going down. */
 244                         int shutdown = 0;
 245
 246                         /* The first thread to get here will have to do the cleanup.
 247                          * Make sure it's really just one.
 248                          */
 249                         begin_critical_section(S_SHUTDOWN);
 250                         if (msock == -1)
 251                         {
 252                                 msock = -2;
 253                                 shutdown = 1;
 254                         }
 255                         end_critical_section(S_SHUTDOWN);
 256                         if (shutdown == 1)
 257                         {/* we're the one to cleanup the mess. */
 258                                 http_destroy_modules(&Hdr);
 259                                 syslog(LOG_DEBUG, "I'm master shutdown: tagging sessions to be killed.\n");
 260                                 shutdown_sessions();
 261                                 syslog(LOG_DEBUG, "master shutdown: waiting for others\n");
 262                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 263                                 syslog(LOG_DEBUG, "master shutdown: cleaning up sessions\n");
 264                                 do_housekeeping();
 265                                 syslog(LOG_DEBUG, "master shutdown: cleaning up libical\n");
 266
 267                                 ShutDownWebcit();
 268
 269                                 syslog(LOG_DEBUG, "master shutdown exiting.\n");
 270                                 exit(0);
 271                         }
 272                         break;
 273                 }
 274                 if (ssock < 0 ) continue;
 275
 276                 check_thread_pool_size();
 277
 278                 /* Now do something. */
 279                 if (msock < 0) {
 280                         if (ssock > 0) close (ssock);
 281                         syslog(LOG_DEBUG, "in between.");
 282                         pthread_exit(NULL);
 283                 } else {
 284                         /* Got it? do some real work! */
 285                         /* Set the SO_REUSEADDR socket option */
 286                         i = 1;
 287                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 288
 289                         /* If we are an HTTPS server, go crypto now. */
 290 #ifdef HAVE_OPENSSL
 291                         if (is_https) {
 292                                 if (starttls(ssock) != 0) {
 293                                         fail_this_transaction = 1;
 294                                         close(ssock);
 295                                 }
 296                         }
 297                         else
 298 #endif
 299                         {
 300                                 int fdflags;
 301                                 fdflags = fcntl(ssock, F_GETFL);
 302                                 if (fdflags < 0)
 303                                         syslog(LOG_WARNING, "unable to get server socket flags! %s \n",
 304                                                 strerror(errno));
 305                                 fdflags = fdflags | O_NONBLOCK;
 306                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 307                                         syslog(LOG_WARNING, "unable to set server socket nonblocking flags! %s \n",
 308                                                 strerror(errno));
 309                         }
 310
 311                         if (fail_this_transaction == 0) {
 312                                 Hdr.http_sock = ssock;
 313
 314                                 /* Perform an HTTP transaction... */
 315                                 context_loop(&Hdr);
 316
 317                                 /* Shut down SSL/TLS if required... */
 318 #ifdef HAVE_OPENSSL
 319                                 if (is_https) {
 320                                         endtls();
 321                                 }
 322 #endif
 323
 324                                 /* ...and close the socket. */
 325                                 if (Hdr.http_sock > 0) {
 326                                         lingering_close(ssock);
 327                                 }
 328                                 http_detach_modules(&Hdr);
 329
 330                         }
 331
 332                 }
 333
 334         } while (!time_to_die);
 335
 336         http_destroy_modules(&Hdr);
 337         syslog(LOG_DEBUG, "Thread exiting.\n");
 338         pthread_exit(NULL);
 339 }
 340
 341
 342 /*
 343  * Shut us down the regular way.
 344  * signum is the signal we want to forward
 345  */
 346 pid_t current_child;
 347 void graceful_shutdown_watcher(int signum) {
 348         syslog(LOG_INFO, "Watcher thread exiting.\n");
 349         write(ExitPipe[0], HKEY("                              "));
 350         kill(current_child, signum);
 351         if (signum != SIGHUP)
 352                 exit(0);
 353 }
 354
 355
 356 /*
 357  * Shut us down the regular way.
 358  * signum is the signal we want to forward
 359  */
 360 pid_t current_child;
 361 void graceful_shutdown(int signum) {
 362         FILE *FD;
 363         int fd;
 364
 365         syslog(LOG_INFO, "WebCit is being shut down on signal %d.\n", signum);
 366         fd = msock;
 367         msock = -1;
 368         time_to_die = 1;
 369         FD=fdopen(fd, "a+");
 370         fflush (FD);
 371         fclose (FD);
 372         close(fd);
 373         write(ExitPipe[0], HKEY("                              "));
 374 }
 375
 376
 377 /*
 378  * Start running as a daemon.
 379  */
 380 void start_daemon(char *pid_file)
 381 {
 382         int status = 0;
 383         pid_t child = 0;
 384         FILE *fp;
 385         int do_restart = 0;
 386
 387         current_child = 0;
 388
 389         /* Close stdin/stdout/stderr and replace them with /dev/null.
 390          * We don't just call close() because we don't want these fd's
 391          * to be reused for other files.
 392          */
 393         chdir("/");
 394
 395         signal(SIGHUP, SIG_IGN);
 396         signal(SIGINT, SIG_IGN);
 397         signal(SIGQUIT, SIG_IGN);
 398
 399         child = fork();
 400         if (child != 0) {
 401                 exit(0);
 402         }
 403
 404         setsid();
 405         umask(0);
 406         freopen("/dev/null", "r", stdin);
 407         freopen("/dev/null", "w", stdout);
 408         freopen("/dev/null", "w", stderr);
 409         signal(SIGTERM, graceful_shutdown_watcher);
 410         signal(SIGHUP, graceful_shutdown_watcher);
 411
 412         do {
 413                 current_child = fork();
 414
 415
 416                 if (current_child < 0) {
 417                         perror("fork");
 418                         ShutDownLibCitadel ();
 419                         exit(errno);
 420                 }
 421
 422                 else if (current_child == 0) {  /* child process */
 423                         signal(SIGHUP, graceful_shutdown);
 424
 425                         return; /* continue starting webcit. */
 426                 }
 427                 else { /* watcher process */
 428                         if (pid_file) {
 429                                 fp = fopen(pid_file, "w");
 430                                 if (fp != NULL) {
 431                                         fprintf(fp, "%d\n", getpid());
 432                                         fclose(fp);
 433                                 }
 434                         }
 435                         waitpid(current_child, &status, 0);
 436                 }
 437
 438                 do_restart = 0;
 439
 440                 /* Did the main process exit with an actual exit code? */
 441                 if (WIFEXITED(status)) {
 442
 443                         /* Exit code 0 means the watcher should exit */
 444                         if (WEXITSTATUS(status) == 0) {
 445                                 do_restart = 0;
 446                         }
 447
 448                         /* Exit code 101-109 means the watcher should exit */
 449                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 450                                 do_restart = 0;
 451                         }
 452
 453                         /* Any other exit code means we should restart. */
 454                         else {
 455                                 do_restart = 1;
 456                         }
 457                 }
 458
 459                 /* Any other type of termination (signals, etc.) should also restart. */
 460                 else {
 461                         do_restart = 1;
 462                 }
 463
 464         } while (do_restart);
 465
 466         if (pid_file) {
 467                 unlink(pid_file);
 468         }
 469         ShutDownLibCitadel ();
 470         exit(WEXITSTATUS(status));
 471 }
 472
 473
 474 /*
 475  * Spawn an additional worker thread into the pool.
 476  */
 477 void spawn_another_worker_thread()
 478 {
 479         pthread_t SessThread;   /* Thread descriptor */
 480         pthread_attr_t attr;    /* Thread attributes */
 481         int ret;
 482
 483         ++num_threads_existing;
 484         ++num_threads_executing;
 485
 486         /* set attributes for the new thread */
 487         pthread_attr_init(&attr);
 488         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 489
 490         /*
 491          * Our per-thread stacks need to be bigger than the default size,
 492          * otherwise the MIME parser crashes on FreeBSD.
 493          */
 494         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 495                 syslog(LOG_WARNING, "pthread_attr_setstacksize: %s\n", strerror(ret));
 496                 pthread_attr_destroy(&attr);
 497         }
 498
 499         /* now create the thread */
 500         if (pthread_create(&SessThread, &attr, (void *(*)(void *)) worker_entry, NULL) != 0) {
 501                 syslog(LOG_WARNING, "Can't create thread: %s\n", strerror(errno));
 502         }
 503
 504         /* free up the attributes */
 505         pthread_attr_destroy(&attr);
 506 }
 507
 508
 509 void
 510 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 511 {
 512         char dirbuffer[PATH_MAX]="";
 513         /* calculate all our path on a central place */
 514     /* where to keep our config */
 515
 516 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 517         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 518                          (home&!relh)?webcitdir:basedir, \
 519              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 520              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 521                          relhome, \
 522              (relhome[0]!='\0')?"/":"",\
 523                          dirbuffer,\
 524                          (dirbuffer[0]!='\0')?"/":"");
 525         basedir=RUNDIR;
 526         COMPUTE_DIRECTORY(socket_dir);
 527         basedir=WWWDIR "/static";
 528         COMPUTE_DIRECTORY(static_dir);
 529         basedir=WWWDIR "/static/icons";
 530         COMPUTE_DIRECTORY(static_icon_dir);
 531         basedir=WWWDIR "/static.local";
 532         COMPUTE_DIRECTORY(static_local_dir);
 533         StripSlashes(static_dir, 1);
 534         StripSlashes(static_icon_dir, 1);
 535         StripSlashes(static_local_dir, 1);
 536
 537         snprintf(file_crpt_file_key,
 538                  sizeof file_crpt_file_key,
 539                  "%s/citadel.key",
 540                  ctdl_key_dir);
 541         snprintf(file_crpt_file_csr,
 542                  sizeof file_crpt_file_csr,
 543                  "%s/citadel.csr",
 544                  ctdl_key_dir);
 545         snprintf(file_crpt_file_cer,
 546                  sizeof file_crpt_file_cer,
 547                  "%s/citadel.cer",
 548                  ctdl_key_dir);
 549
 550
 551         basedir=ETCDIR;
 552         COMPUTE_DIRECTORY(etc_dir);
 553         StripSlashes(etc_dir, 1);
 554         snprintf(file_etc_mimelist,
 555                  sizeof file_etc_mimelist,
 556                  "%s/nogz-mimetypes.txt",
 557                  etc_dir);
 558
 559         /* we should go somewhere we can leave our coredump, if enabled... */
 560         syslog(LOG_INFO, "Changing directory to %s\n", socket_dir);
 561         if (chdir(webcitdir) != 0) {
 562                 perror("chdir");
 563         }
 564 }
 565
 566 void drop_root(uid_t UID)
 567 {
 568         struct passwd pw, *pwp = NULL;
 569
 570         /*
 571          * Now that we've bound the sockets, change to the Citadel user id and its
 572          * corresponding group ids
 573          */
 574         if (UID != -1) {
 575
 576 #ifdef HAVE_GETPWUID_R
 577 #ifdef SOLARIS_GETPWUID
 578                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 579 #else /* SOLARIS_GETPWUID */
 580                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 581 #endif /* SOLARIS_GETPWUID */
 582 #else /* HAVE_GETPWUID_R */
 583                 pwp = NULL;
 584 #endif /* HAVE_GETPWUID_R */
 585
 586                 if (pwp == NULL)
 587                         syslog(LOG_CRIT, "WARNING: getpwuid(%d): %s\n"
 588                                 "Group IDs will be incorrect.\n", UID,
 589                                 strerror(errno));
 590                 else {
 591                         initgroups(pw.pw_name, pw.pw_gid);
 592                         if (setgid(pw.pw_gid))
 593                                 syslog(LOG_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 594                                         strerror(errno));
 595                 }
 596                 syslog(LOG_INFO, "Changing uid to %ld\n", (long)UID);
 597                 if (setuid(UID) != 0) {
 598                         syslog(LOG_CRIT, "setuid() failed: %s\n", strerror(errno));
 599                 }
 600 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 601                 prctl(PR_SET_DUMPABLE, 1);
 602 #endif
 603         }
 604 }
 605
 606
 607 /*
 608  * print the actual stack frame.
 609  */
 610 void wc_backtrace(long LogLevel)
 611 {
 612 #ifdef HAVE_BACKTRACE
 613         void *stack_frames[50];
 614         size_t size, i;
 615         char **strings;
 616
 617
 618         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 619         strings = backtrace_symbols(stack_frames, size);
 620         for (i = 0; i < size; i++) {
 621                 if (strings != NULL)
 622                         syslog(LogLevel, "%s\n", strings[i]);
 623                 else
 624                         syslog(LogLevel, "%p\n", stack_frames[i]);
 625         }
 626         free(strings);
 627 #endif
 628 }