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