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