webcit/sysdep.c

   1 /*
   2  * WebCit "system dependent" code.
   3  *
   4  * Copyright (c) 1996-2011 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 as published by
   8  * the Free Software Foundation; either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "sysdep.h"
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <stdio.h>
  25 #include <fcntl.h>
  26 #include <ctype.h>
  27 #include <signal.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <sys/wait.h>
  31 #include <sys/socket.h>
  32 #include <syslog.h>
  33 #include <sys/syslog.h>
  34
  35 #if TIME_WITH_SYS_TIME
  36 # include <sys/time.h>
  37 # include <time.h>
  38 #else
  39 # if HAVE_SYS_TIME_H
  40 #  include <sys/time.h>
  41 # else
  42 #  include <time.h>
  43 # endif
  44 #endif
  45
  46 #include <limits.h>
  47 #include <sys/resource.h>
  48 #include <netinet/in.h>
  49 #include <netinet/tcp.h>
  50 #include <arpa/inet.h>
  51 #include <netdb.h>
  52 #include <sys/un.h>
  53 #include <string.h>
  54 #include <pwd.h>
  55 #include <errno.h>
  56 #include <stdarg.h>
  57 #include <grp.h>
  58 #ifdef HAVE_PTHREAD_H
  59 #include <pthread.h>
  60 #endif
  61 #include "webcit.h"
  62 #include "sysdep.h"
  63
  64 #ifdef HAVE_SYS_SELECT_H
  65 #include <sys/select.h>
  66 #endif
  67
  68 #ifndef HAVE_SNPRINTF
  69 #include "snprintf.h"
  70 #endif
  71 #include "webserver.h"
  72 #include "modules_init.h"
  73 #if HAVE_BACKTRACE
  74 #include <execinfo.h>
  75 #endif
  76
  77 pthread_mutex_t Critters[MAX_SEMAPHORES];       /* Things needing locking */
  78 pthread_key_t MyConKey;                         /* TSD key for MyContext() */
  79 pthread_key_t MyReq;                            /* TSD key for MyReq() */
  80 int msock;                      /* master listening socket */
  81 int time_to_die = 0;            /* Nonzero if server is shutting down */
  82 int verbosity = 9;              /* Logging level */
  83
  84 extern void *context_loop(ParsedHttpHdrs *Hdr);
  85 extern void *housekeeping_loop(void);
  86 extern void do_housekeeping(void);
  87
  88 char ctdl_key_dir[PATH_MAX]=SSL_DIR;
  89 char file_crpt_file_key[PATH_MAX]="";
  90 char file_crpt_file_csr[PATH_MAX]="";
  91 char file_crpt_file_cer[PATH_MAX]="";
  92
  93 const char editor_absolut_dir[PATH_MAX]=EDITORDIR;      /* nailed to what configure gives us. */
  94 char static_dir[PATH_MAX];              /* calculated on startup */
  95 char static_local_dir[PATH_MAX];                /* calculated on startup */
  96 char static_icon_dir[PATH_MAX];          /* where should we find our mime icons? */
  97 char  *static_dirs[]={                          /* needs same sort order as the web mapping */
  98         (char*)static_dir,                      /* our templates on disk */
  99         (char*)static_local_dir,                /* user provided templates disk */
 100         (char*)editor_absolut_dir,              /* the editor on disk */
 101         (char*)static_icon_dir                  /* our icons... */
 102 };
 103
 104 int ExitPipe[2];
 105
 106 void InitialiseSemaphores(void)
 107 {
 108         int i;
 109
 110         /* Set up a bunch of semaphores to be used for critical sections */
 111         for (i=0; i<MAX_SEMAPHORES; ++i) {
 112                 pthread_mutex_init(&Critters[i], NULL);
 113         }
 114
 115         if (pipe(ExitPipe))
 116         {
 117                 syslog(2, "Failed to open exit pipe: %d [%s]\n",
 118                        errno,
 119                        strerror(errno));
 120
 121                 exit(-1);
 122         }
 123 }
 124
 125 /*
 126  * Obtain a semaphore lock to begin a critical section.
 127  */
 128 void begin_critical_section(int which_one)
 129 {
 130         pthread_mutex_lock(&Critters[which_one]);
 131 }
 132
 133 /*
 134  * Release a semaphore lock to end a critical section.
 135  */
 136 void end_critical_section(int which_one)
 137 {
 138         pthread_mutex_unlock(&Critters[which_one]);
 139 }
 140
 141
 142 void ShutDownWebcit(void)
 143 {
 144         free_zone_directory ();
 145         icaltimezone_release_zone_tab ();
 146         icalmemory_free_ring ();
 147         ShutDownLibCitadel ();
 148         shutdown_modules ();
 149 #ifdef HAVE_OPENSSL
 150         if (is_https) {
 151                 shutdown_ssl();
 152         }
 153 #endif
 154 }
 155
 156 /*
 157  * Entry point for worker threads
 158  */
 159 void worker_entry(void)
 160 {
 161         int ssock;
 162         int i = 0;
 163         int fail_this_transaction = 0;
 164         ParsedHttpHdrs Hdr;
 165
 166         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 167         Hdr.HR.eReqType = eGET;
 168         http_new_modules(&Hdr);
 169
 170         do {
 171                 /* Each worker thread blocks on accept() while waiting for something to do. */
 172                 fail_this_transaction = 0;
 173                 ssock = -1;
 174                 errno = EAGAIN;
 175                 do {
 176                         fd_set wset;
 177                         --num_threads_executing;
 178                         FD_ZERO(&wset);
 179                         FD_SET(msock, &wset);
 180                         FD_SET(ExitPipe[1], &wset);
 181
 182                         select(msock + 1, NULL, &wset, NULL, NULL);
 183                         if (time_to_die)
 184                                 break;
 185
 186                         ssock = accept(msock, NULL, 0);
 187                         ++num_threads_executing;
 188                         if (ssock < 0) fail_this_transaction = 1;
 189                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 190
 191                 if ((msock == -1)||(time_to_die))
 192                 {/* ok, we're going down. */
 193                         int shutdown = 0;
 194
 195                         /* The first thread to get here will have to do the cleanup.
 196                          * Make sure it's really just one.
 197                          */
 198                         begin_critical_section(S_SHUTDOWN);
 199                         if (msock == -1)
 200                         {
 201                                 msock = -2;
 202                                 shutdown = 1;
 203                         }
 204                         end_critical_section(S_SHUTDOWN);
 205                         if (shutdown == 1)
 206                         {/* we're the one to cleanup the mess. */
 207                                 http_destroy_modules(&Hdr);
 208                                 syslog(2, "I'm master shutdown: tagging sessions to be killed.\n");
 209                                 shutdown_sessions();
 210                                 syslog(2, "master shutdown: waiting for others\n");
 211                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 212                                 syslog(2, "master shutdown: cleaning up sessions\n");
 213                                 do_housekeeping();
 214                                 syslog(2, "master shutdown: cleaning up libical\n");
 215
 216                                 ShutDownWebcit();
 217
 218                                 syslog(2, "master shutdown exiting.\n");
 219                                 exit(0);
 220                         }
 221                         break;
 222                 }
 223                 if (ssock < 0 ) continue;
 224
 225                 check_thread_pool_size();
 226
 227                 /* Now do something. */
 228                 if (msock < 0) {
 229                         if (ssock > 0) close (ssock);
 230                         syslog(2, "in between.");
 231                         pthread_exit(NULL);
 232                 } else {
 233                         /* Got it? do some real work! */
 234                         /* Set the SO_REUSEADDR socket option */
 235                         i = 1;
 236                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 237
 238                         /* If we are an HTTPS server, go crypto now. */
 239 #ifdef HAVE_OPENSSL
 240                         if (is_https) {
 241                                 if (starttls(ssock) != 0) {
 242                                         fail_this_transaction = 1;
 243                                         close(ssock);
 244                                 }
 245                         }
 246                         else
 247 #endif
 248                         {
 249                                 int fdflags;
 250                                 fdflags = fcntl(ssock, F_GETFL);
 251                                 if (fdflags < 0)
 252                                         syslog(1, "unable to get server socket flags! %s \n",
 253                                                 strerror(errno));
 254                                 fdflags = fdflags | O_NONBLOCK;
 255                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 256                                         syslog(1, "unable to set server socket nonblocking flags! %s \n",
 257                                                 strerror(errno));
 258                         }
 259
 260                         if (fail_this_transaction == 0) {
 261                                 Hdr.http_sock = ssock;
 262
 263                                 /* Perform an HTTP transaction... */
 264                                 context_loop(&Hdr);
 265
 266                                 /* Shut down SSL/TLS if required... */
 267 #ifdef HAVE_OPENSSL
 268                                 if (is_https) {
 269                                         endtls();
 270                                 }
 271 #endif
 272
 273                                 /* ...and close the socket. */
 274                                 if (Hdr.http_sock > 0) {
 275                                         lingering_close(ssock);
 276                                 }
 277                                 http_detach_modules(&Hdr);
 278
 279                         }
 280
 281                 }
 282
 283         } while (!time_to_die);
 284
 285         http_destroy_modules(&Hdr);
 286         syslog(1, "Thread exiting.\n");
 287         pthread_exit(NULL);
 288 }
 289
 290
 291 /*
 292  * Shut us down the regular way.
 293  * signum is the signal we want to forward
 294  */
 295 pid_t current_child;
 296 void graceful_shutdown_watcher(int signum) {
 297         syslog(1, "Watcher thread exiting.\n");
 298         write(ExitPipe[0], HKEY("                              "));
 299         kill(current_child, signum);
 300         if (signum != SIGHUP)
 301                 exit(0);
 302 }
 303
 304
 305 /*
 306  * Shut us down the regular way.
 307  * signum is the signal we want to forward
 308  */
 309 pid_t current_child;
 310 void graceful_shutdown(int signum) {
 311         FILE *FD;
 312         int fd;
 313
 314         syslog(1, "WebCit is being shut down on signal %d.\n", signum);
 315         fd = msock;
 316         msock = -1;
 317         time_to_die = 1;
 318         FD=fdopen(fd, "a+");
 319         fflush (FD);
 320         fclose (FD);
 321         close(fd);
 322         write(ExitPipe[0], HKEY("                              "));
 323 }
 324
 325
 326 /*
 327  * Start running as a daemon.
 328  */
 329 void start_daemon(char *pid_file)
 330 {
 331         int status = 0;
 332         pid_t child = 0;
 333         FILE *fp;
 334         int do_restart = 0;
 335         int rv;
 336         FILE *rvfp = NULL;
 337
 338         current_child = 0;
 339
 340         /* Close stdin/stdout/stderr and replace them with /dev/null.
 341          * We don't just call close() because we don't want these fd's
 342          * to be reused for other files.
 343          */
 344         rv = chdir("/");
 345
 346         signal(SIGHUP, SIG_IGN);
 347         signal(SIGINT, SIG_IGN);
 348         signal(SIGQUIT, SIG_IGN);
 349
 350         child = fork();
 351         if (child != 0) {
 352                 exit(0);
 353         }
 354
 355         setsid();
 356         umask(0);
 357         rvfp = freopen("/dev/null", "r", stdin);
 358         rvfp = freopen("/dev/null", "w", stdout);
 359         rvfp = freopen("/dev/null", "w", stderr);
 360         signal(SIGTERM, graceful_shutdown_watcher);
 361         signal(SIGHUP, graceful_shutdown_watcher);
 362
 363         do {
 364                 current_child = fork();
 365
 366
 367                 if (current_child < 0) {
 368                         perror("fork");
 369                         ShutDownLibCitadel ();
 370                         exit(errno);
 371                 }
 372
 373                 else if (current_child == 0) {  /* child process */
 374                         signal(SIGHUP, graceful_shutdown);
 375
 376                         return; /* continue starting webcit. */
 377                 }
 378                 else { /* watcher process */
 379                         if (pid_file) {
 380                                 fp = fopen(pid_file, "w");
 381                                 if (fp != NULL) {
 382                                         fprintf(fp, "%d\n", getpid());
 383                                         fclose(fp);
 384                                 }
 385                         }
 386                         waitpid(current_child, &status, 0);
 387                 }
 388
 389                 do_restart = 0;
 390
 391                 /* Did the main process exit with an actual exit code? */
 392                 if (WIFEXITED(status)) {
 393
 394                         /* Exit code 0 means the watcher should exit */
 395                         if (WEXITSTATUS(status) == 0) {
 396                                 do_restart = 0;
 397                         }
 398
 399                         /* Exit code 101-109 means the watcher should exit */
 400                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 401                                 do_restart = 0;
 402                         }
 403
 404                         /* Any other exit code means we should restart. */
 405                         else {
 406                                 do_restart = 1;
 407                         }
 408                 }
 409
 410                 /* Any other type of termination (signals, etc.) should also restart. */
 411                 else {
 412                         do_restart = 1;
 413                 }
 414
 415         } while (do_restart);
 416
 417         if (pid_file) {
 418                 unlink(pid_file);
 419         }
 420         ShutDownLibCitadel ();
 421         exit(WEXITSTATUS(status));
 422 }
 423
 424
 425 /*
 426  * Spawn an additional worker thread into the pool.
 427  */
 428 void spawn_another_worker_thread()
 429 {
 430         pthread_t SessThread;   /* Thread descriptor */
 431         pthread_attr_t attr;    /* Thread attributes */
 432         int ret;
 433
 434         ++num_threads_existing;
 435         ++num_threads_executing;
 436
 437         /* set attributes for the new thread */
 438         pthread_attr_init(&attr);
 439         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 440
 441         /*
 442          * Our per-thread stacks need to be bigger than the default size,
 443          * otherwise the MIME parser crashes on FreeBSD.
 444          */
 445         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 446                 syslog(1, "pthread_attr_setstacksize: %s\n", strerror(ret));
 447                 pthread_attr_destroy(&attr);
 448         }
 449
 450         /* now create the thread */
 451         if (pthread_create(&SessThread, &attr, (void *(*)(void *)) worker_entry, NULL) != 0) {
 452                 syslog(1, "Can't create thread: %s\n", strerror(errno));
 453         }
 454
 455         /* free up the attributes */
 456         pthread_attr_destroy(&attr);
 457 }
 458
 459
 460 void
 461 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 462 {
 463         char dirbuffer[PATH_MAX]="";
 464         /* calculate all our path on a central place */
 465     /* where to keep our config */
 466
 467 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 468         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 469                          (home&!relh)?webcitdir:basedir, \
 470              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 471              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 472                          relhome, \
 473              (relhome[0]!='\0')?"/":"",\
 474                          dirbuffer,\
 475                          (dirbuffer[0]!='\0')?"/":"");
 476         basedir=RUNDIR;
 477         COMPUTE_DIRECTORY(socket_dir);
 478         basedir=WWWDIR "/static";
 479         COMPUTE_DIRECTORY(static_dir);
 480         basedir=WWWDIR "/static/icons";
 481         COMPUTE_DIRECTORY(static_icon_dir);
 482         basedir=WWWDIR "/static.local";
 483         COMPUTE_DIRECTORY(static_local_dir);
 484         StripSlashes(static_dir, 1);
 485         StripSlashes(static_icon_dir, 1);
 486         StripSlashes(static_local_dir, 1);
 487
 488         snprintf(file_crpt_file_key,
 489                  sizeof file_crpt_file_key,
 490                  "%s/citadel.key",
 491                  ctdl_key_dir);
 492         snprintf(file_crpt_file_csr,
 493                  sizeof file_crpt_file_csr,
 494                  "%s/citadel.csr",
 495                  ctdl_key_dir);
 496         snprintf(file_crpt_file_cer,
 497                  sizeof file_crpt_file_cer,
 498                  "%s/citadel.cer",
 499                  ctdl_key_dir);
 500
 501         /* we should go somewhere we can leave our coredump, if enabled... */
 502         syslog(9, "Changing directory to %s\n", socket_dir);
 503         if (chdir(webcitdir) != 0) {
 504                 perror("chdir");
 505         }
 506 }
 507
 508 void drop_root(uid_t UID)
 509 {
 510         struct passwd pw, *pwp = NULL;
 511
 512         /*
 513          * Now that we've bound the sockets, change to the Citadel user id and its
 514          * corresponding group ids
 515          */
 516         if (UID != -1) {
 517
 518 #ifdef HAVE_GETPWUID_R
 519 #ifdef SOLARIS_GETPWUID
 520                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 521 #else /* SOLARIS_GETPWUID */
 522                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 523 #endif /* SOLARIS_GETPWUID */
 524 #else /* HAVE_GETPWUID_R */
 525                 pwp = NULL;
 526 #endif /* HAVE_GETPWUID_R */
 527
 528                 if (pwp == NULL)
 529                         syslog(LOG_CRIT, "WARNING: getpwuid(%d): %s\n"
 530                                 "Group IDs will be incorrect.\n", UID,
 531                                 strerror(errno));
 532                 else {
 533                         initgroups(pw.pw_name, pw.pw_gid);
 534                         if (setgid(pw.pw_gid))
 535                                 syslog(LOG_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 536                                         strerror(errno));
 537                 }
 538                 syslog(LOG_INFO, "Changing uid to %ld\n", (long)UID);
 539                 if (setuid(UID) != 0) {
 540                         syslog(LOG_CRIT, "setuid() failed: %s\n", strerror(errno));
 541                 }
 542 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 543                 prctl(PR_SET_DUMPABLE, 1);
 544 #endif
 545         }
 546 }
 547
 548
 549 /*
 550  * print the actual stack frame.
 551  */
 552 void wc_backtrace(void)
 553 {
 554 #ifdef HAVE_BACKTRACE
 555         void *stack_frames[50];
 556         size_t size, i;
 557         char **strings;
 558
 559
 560         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 561         strings = backtrace_symbols(stack_frames, size);
 562         for (i = 0; i < size; i++) {
 563                 if (strings != NULL)
 564                         syslog(1, "%s\n", strings[i]);
 565                 else
 566                         syslog(1, "%p\n", stack_frames[i]);
 567         }
 568         free(strings);
 569 #endif
 570 }