webcit/sysdep.c

   1 /*
   2  * $Id$
   3  *
   4  * Citadel "system dependent" stuff.
   5  * See copyright.txt for copyright information.
   6  *
   7  * Here's where we (hopefully) have most parts of the Citadel server that
   8  * would need to be altered to run the server in a non-POSIX environment.
   9  *
  10  * If we ever port to a different platform and either have multiple
  11  * variants of this file or simply load it up with #ifdefs.
  12  *
  13  */
  14 #include "sysdep.h"
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17 #include <stdio.h>
  18 #include <fcntl.h>
  19 #include <ctype.h>
  20 #include <signal.h>
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <sys/wait.h>
  24 #include <sys/socket.h>
  25 #include <syslog.h>
  26 #include <sys/syslog.h>
  27
  28 #if TIME_WITH_SYS_TIME
  29 # include <sys/time.h>
  30 # include <time.h>
  31 #else
  32 # if HAVE_SYS_TIME_H
  33 #  include <sys/time.h>
  34 # else
  35 #  include <time.h>
  36 # endif
  37 #endif
  38
  39 #include <limits.h>
  40 #include <sys/resource.h>
  41 #include <netinet/in.h>
  42 #include <netinet/tcp.h>
  43 #include <arpa/inet.h>
  44 #include <netdb.h>
  45 #include <sys/un.h>
  46 #include <string.h>
  47 #include <pwd.h>
  48 #include <errno.h>
  49 #include <stdarg.h>
  50 #include <grp.h>
  51 #ifdef HAVE_PTHREAD_H
  52 #include <pthread.h>
  53 #endif
  54 #include "webcit.h"
  55 #include "sysdep.h"
  56
  57 #ifdef HAVE_SYS_SELECT_H
  58 #include <sys/select.h>
  59 #endif
  60
  61 #ifndef HAVE_SNPRINTF
  62 #include "snprintf.h"
  63 #endif
  64 #include "webserver.h"
  65 #include "modules_init.h"
  66 #if HAVE_BACKTRACE
  67 #include <execinfo.h>
  68 #endif
  69
  70 pthread_mutex_t Critters[MAX_SEMAPHORES];       /* Things needing locking */
  71 pthread_key_t MyConKey;                         /* TSD key for MyContext() */
  72 pthread_key_t MyReq;                            /* TSD key for MyReq() */
  73 int msock;                      /* master listening socket */
  74 int time_to_die = 0;            /* Nonzero if server is shutting down */
  75 int verbosity = 9;              /* Logging level */
  76
  77 extern void *context_loop(ParsedHttpHdrs *Hdr);
  78 extern void *housekeeping_loop(void);
  79
  80 char ctdl_key_dir[PATH_MAX]=SSL_DIR;
  81 char file_crpt_file_key[PATH_MAX]="";
  82 char file_crpt_file_csr[PATH_MAX]="";
  83 char file_crpt_file_cer[PATH_MAX]="";
  84
  85 const char editor_absolut_dir[PATH_MAX]=EDITORDIR;      /* nailed to what configure gives us. */
  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 void InitialiseSemaphores(void)
  97 {
  98         int i;
  99
 100         /* Set up a bunch of semaphores to be used for critical sections */
 101         for (i=0; i<MAX_SEMAPHORES; ++i) {
 102                 pthread_mutex_init(&Critters[i], NULL);
 103         }
 104 }
 105
 106 /*
 107  * Obtain a semaphore lock to begin a critical section.
 108  */
 109 void begin_critical_section(int which_one)
 110 {
 111         /* lprintf(CTDL_DEBUG, "begin_critical_section(%d)\n", which_one); */
 112         pthread_mutex_lock(&Critters[which_one]);
 113 }
 114
 115 /*
 116  * Release a semaphore lock to end a critical section.
 117  */
 118 void end_critical_section(int which_one)
 119 {
 120         pthread_mutex_unlock(&Critters[which_one]);
 121 }
 122
 123
 124 void ShutDownWebcit(void)
 125 {
 126         free_zone_directory ();
 127         icaltimezone_release_zone_tab ();
 128         icalmemory_free_ring ();
 129         ShutDownLibCitadel ();
 130         shutdown_modules ();
 131 #ifdef HAVE_OPENSSL
 132         if (is_https) {
 133                 shutdown_ssl();
 134         }
 135 #endif
 136 }
 137
 138 /*
 139  * Entry point for worker threads
 140  */
 141 void worker_entry(void)
 142 {
 143         int ssock;
 144         int i = 0;
 145         int fail_this_transaction = 0;
 146         int ret;
 147         struct timeval tv;
 148         fd_set readset, tempset;
 149         ParsedHttpHdrs Hdr;
 150
 151         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 152         Hdr.HR.eReqType = eGET;
 153         http_new_modules(&Hdr);
 154         tv.tv_sec = 0;
 155         tv.tv_usec = 10000;
 156         FD_ZERO(&readset);
 157         FD_SET(msock, &readset);
 158
 159         do {
 160                 /* Only one thread can accept at a time */
 161                 fail_this_transaction = 0;
 162                 ssock = -1;
 163                 errno = EAGAIN;
 164                 do {
 165                         ret = -1; /* just one at once should select... */
 166                         begin_critical_section(S_SELECT);
 167
 168                         FD_ZERO(&tempset);
 169                         if (msock > 0) FD_SET(msock, &tempset);
 170                         tv.tv_sec = 0;
 171                         tv.tv_usec = 10000;
 172                         if (msock > 0)  ret = select(msock+1, &tempset, NULL, NULL,  &tv);
 173                         end_critical_section(S_SELECT);
 174                         if ((ret < 0) && (errno != EINTR) && (errno != EAGAIN))
 175                         {/* EINTR and EAGAIN are thrown but not of interest. */
 176                                 lprintf(2, "accept() failed:%d %s\n",
 177                                         errno, strerror(errno));
 178                         }
 179                         else if ((ret > 0) && (msock > 0) && FD_ISSET(msock, &tempset))
 180                         {/* Successfully selected, and still not shutting down? Accept! */
 181                                 ssock = accept(msock, NULL, 0);
 182                         }
 183
 184                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 185
 186                 if ((msock == -1)||(time_to_die))
 187                 {/* ok, we're going down. */
 188                         int shutdown = 0;
 189
 190                         /* the first to come here will have to do the cleanup.
 191                          * make shure its realy just one.
 192                          */
 193                         begin_critical_section(S_SHUTDOWN);
 194                         if (msock == -1)
 195                         {
 196                                 msock = -2;
 197                                 shutdown = 1;
 198                         }
 199                         end_critical_section(S_SHUTDOWN);
 200                         if (shutdown == 1)
 201                         {/* we're the one to cleanup the mess. */
 202                                 http_destroy_modules(&Hdr);
 203                                 lprintf(2, "I'm master shutdown: tagging sessions to be killed.\n");
 204                                 shutdown_sessions();
 205                                 lprintf(2, "master shutdown: waiting for others\n");
 206                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 207                                 lprintf(2, "master shutdown: cleaning up sessions\n");
 208                                 do_housekeeping();
 209                                 lprintf(2, "master shutdown: cleaning up libical\n");
 210
 211                                 ShutDownWebcit();
 212
 213                                 lprintf(2, "master shutdown exiting!.\n");
 214                                 exit(0);
 215                         }
 216                         break;
 217                 }
 218                 if (ssock < 0 ) continue;
 219
 220                 if (msock < 0) {
 221                         if (ssock > 0) close (ssock);
 222                         lprintf(2, "inbetween.");
 223                         pthread_exit(NULL);
 224                 } else { /* Got it? do some real work! */
 225                         /* Set the SO_REUSEADDR socket option */
 226                         i = 1;
 227                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
 228                                    &i, sizeof(i));
 229
 230                         /* If we are an HTTPS server, go crypto now. */
 231 #ifdef HAVE_OPENSSL
 232                         if (is_https) {
 233                                 if (starttls(ssock) != 0) {
 234                                         fail_this_transaction = 1;
 235                                         close(ssock);
 236                                 }
 237                         }
 238                         else
 239 #endif
 240                         {
 241                                 int fdflags;
 242                                 fdflags = fcntl(ssock, F_GETFL);
 243                                 if (fdflags < 0)
 244                                         lprintf(1, "unable to get server socket flags! %s \n",
 245                                                 strerror(errno));
 246                                 fdflags = fdflags | O_NONBLOCK;
 247                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 248                                         lprintf(1, "unable to set server socket nonblocking flags! %s \n",
 249                                                 strerror(errno));
 250                         }
 251
 252                         if (fail_this_transaction == 0) {
 253                                 Hdr.http_sock = ssock;
 254
 255                                 /* Perform an HTTP transaction... */
 256                                 context_loop(&Hdr);
 257
 258                                 /* Shut down SSL/TLS if required... */
 259 #ifdef HAVE_OPENSSL
 260                                 if (is_https) {
 261                                         endtls();
 262                                 }
 263 #endif
 264
 265                                 /* ...and close the socket. */
 266                                 if (Hdr.http_sock > 0)
 267                                         lingering_close(ssock);
 268                                 http_detach_modules(&Hdr);
 269
 270                         }
 271
 272                 }
 273
 274         } while (!time_to_die);
 275
 276         http_destroy_modules(&Hdr);
 277         lprintf (1, "bye\n");
 278         pthread_exit(NULL);
 279 }
 280
 281 /*
 282  * print log messages
 283  * logs to stderr if loglevel is lower than the verbosity set at startup
 284  *
 285  * loglevel     level of the message
 286  * format       the printf like format string
 287  * ...          the strings to put into format
 288  */
 289 int lprintf(int loglevel, const char *format, ...)
 290 {
 291         va_list ap;
 292
 293         if (loglevel <= verbosity) {
 294                 va_start(ap, format);
 295                 vfprintf(stderr, format, ap);
 296                 va_end(ap);
 297                 fflush(stderr);
 298         }
 299         return 1;
 300 }
 301
 302 /*
 303  * Shut us down the regular way.
 304  * signum is the signal we want to forward
 305  */
 306 pid_t current_child;
 307 void graceful_shutdown_watcher(int signum) {
 308         lprintf (1, "bye; shutting down watcher.");
 309         kill(current_child, signum);
 310         if (signum != SIGHUP)
 311                 exit(0);
 312 }
 313
 314
 315
 316
 317 /*
 318  * Shut us down the regular way.
 319  * signum is the signal we want to forward
 320  */
 321 pid_t current_child;
 322 void graceful_shutdown(int signum) {
 323         FILE *FD;
 324         int fd;
 325
 326         lprintf (1, "WebCit is being shut down on signal %d.\n", signum);
 327         fd = msock;
 328         msock = -1;
 329         time_to_die = 1;
 330         FD=fdopen(fd, "a+");
 331         fflush (FD);
 332         fclose (FD);
 333         close(fd);
 334 }
 335
 336
 337 /*
 338  * Start running as a daemon.
 339  */
 340 void start_daemon(char *pid_file)
 341 {
 342         int status = 0;
 343         pid_t child = 0;
 344         FILE *fp;
 345         int do_restart = 0;
 346         int rv;
 347         FILE *rvfp = NULL;
 348
 349         current_child = 0;
 350
 351         /* Close stdin/stdout/stderr and replace them with /dev/null.
 352          * We don't just call close() because we don't want these fd's
 353          * to be reused for other files.
 354          */
 355         rv = chdir("/");
 356
 357         signal(SIGHUP, SIG_IGN);
 358         signal(SIGINT, SIG_IGN);
 359         signal(SIGQUIT, SIG_IGN);
 360
 361         child = fork();
 362         if (child != 0) {
 363                 exit(0);
 364         }
 365
 366         setsid();
 367         umask(0);
 368         rvfp = freopen("/dev/null", "r", stdin);
 369         rvfp = freopen("/dev/null", "w", stdout);
 370         rvfp = freopen("/dev/null", "w", stderr);
 371         signal(SIGTERM, graceful_shutdown_watcher);
 372         signal(SIGHUP, graceful_shutdown_watcher);
 373
 374         do {
 375                 current_child = fork();
 376
 377
 378                 if (current_child < 0) {
 379                         perror("fork");
 380                         ShutDownLibCitadel ();
 381                         exit(errno);
 382                 }
 383
 384                 else if (current_child == 0) {  /* child process */
 385                         signal(SIGHUP, graceful_shutdown);
 386
 387                         return; /* continue starting webcit. */
 388                 }
 389                 else { /* watcher process */
 390                         if (pid_file) {
 391                                 fp = fopen(pid_file, "w");
 392                                 if (fp != NULL) {
 393                                         fprintf(fp, "%d\n", getpid());
 394                                         fclose(fp);
 395                                 }
 396                         }
 397                         waitpid(current_child, &status, 0);
 398                 }
 399
 400                 do_restart = 0;
 401
 402                 /* Did the main process exit with an actual exit code? */
 403                 if (WIFEXITED(status)) {
 404
 405                         /* Exit code 0 means the watcher should exit */
 406                         if (WEXITSTATUS(status) == 0) {
 407                                 do_restart = 0;
 408                         }
 409
 410                         /* Exit code 101-109 means the watcher should exit */
 411                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 412                                 do_restart = 0;
 413                         }
 414
 415                         /* Any other exit code means we should restart. */
 416                         else {
 417                                 do_restart = 1;
 418                         }
 419                 }
 420
 421                 /* Any other type of termination (signals, etc.) should also restart. */
 422                 else {
 423                         do_restart = 1;
 424                 }
 425
 426         } while (do_restart);
 427
 428         if (pid_file) {
 429                 unlink(pid_file);
 430         }
 431         ShutDownLibCitadel ();
 432         exit(WEXITSTATUS(status));
 433 }
 434
 435 /*
 436  * Spawn an additional worker thread into the pool.
 437  */
 438 void spawn_another_worker_thread()
 439 {
 440         pthread_t SessThread;   /* Thread descriptor */
 441         pthread_attr_t attr;    /* Thread attributes */
 442         int ret;
 443
 444         lprintf(3, "Creating a new thread.  Pool size is now %d\n", ++num_threads);
 445
 446         /* set attributes for the new thread */
 447         pthread_attr_init(&attr);
 448         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 449
 450         /*
 451          * Our per-thread stacks need to be bigger than the default size,
 452          * otherwise the MIME parser crashes on FreeBSD.
 453          */
 454         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 455                 lprintf(1, "pthread_attr_setstacksize: %s\n",
 456                         strerror(ret));
 457                 pthread_attr_destroy(&attr);
 458         }
 459
 460         /* now create the thread */
 461         if (pthread_create(&SessThread, &attr,
 462                            (void *(*)(void *)) worker_entry, NULL)
 463             != 0) {
 464                 lprintf(1, "Can't create thread: %s\n", strerror(errno));
 465         }
 466
 467         /* free up the attributes */
 468         pthread_attr_destroy(&attr);
 469 }
 470
 471
 472 void
 473 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 474 {
 475         char dirbuffer[PATH_MAX]="";
 476         /* calculate all our path on a central place */
 477     /* where to keep our config */
 478
 479 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 480         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 481                          (home&!relh)?webcitdir:basedir, \
 482              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 483              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 484                          relhome, \
 485              (relhome[0]!='\0')?"/":"",\
 486                          dirbuffer,\
 487                          (dirbuffer[0]!='\0')?"/":"");
 488         basedir=RUNDIR;
 489         COMPUTE_DIRECTORY(socket_dir);
 490         basedir=WWWDIR "/static";
 491         COMPUTE_DIRECTORY(static_dir);
 492         basedir=WWWDIR "/static/icons";
 493         COMPUTE_DIRECTORY(static_icon_dir);
 494         basedir=WWWDIR "/static.local";
 495         COMPUTE_DIRECTORY(static_local_dir);
 496         StripSlashes(static_dir, 1);
 497         StripSlashes(static_icon_dir, 1);
 498         StripSlashes(static_local_dir, 1);
 499
 500         snprintf(file_crpt_file_key,
 501                  sizeof file_crpt_file_key,
 502                  "%s/citadel.key",
 503                  ctdl_key_dir);
 504         snprintf(file_crpt_file_csr,
 505                  sizeof file_crpt_file_csr,
 506                  "%s/citadel.csr",
 507                  ctdl_key_dir);
 508         snprintf(file_crpt_file_cer,
 509                  sizeof file_crpt_file_cer,
 510                  "%s/citadel.cer",
 511                  ctdl_key_dir);
 512
 513         /* we should go somewhere we can leave our coredump, if enabled... */
 514         lprintf(9, "Changing directory to %s\n", socket_dir);
 515         if (chdir(webcitdir) != 0) {
 516                 perror("chdir");
 517         }
 518 }
 519 void drop_root(uid_t UID)
 520 {
 521         struct passwd pw, *pwp = NULL;
 522
 523         /*
 524          * Now that we've bound the sockets, change to the Citadel user id and its
 525          * corresponding group ids
 526          */
 527         if (UID != -1) {
 528
 529 #ifdef HAVE_GETPWUID_R
 530 #ifdef SOLARIS_GETPWUID
 531                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 532 #else // SOLARIS_GETPWUID
 533                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 534 #endif // SOLARIS_GETPWUID
 535 #else // HAVE_GETPWUID_R
 536                 pwp = NULL;
 537 #endif // HAVE_GETPWUID_R
 538
 539                 if (pwp == NULL)
 540                         lprintf(CTDL_CRIT, "WARNING: getpwuid(%ld): %s\n"
 541                                 "Group IDs will be incorrect.\n", UID,
 542                                 strerror(errno));
 543                 else {
 544                         initgroups(pw.pw_name, pw.pw_gid);
 545                         if (setgid(pw.pw_gid))
 546                                 lprintf(CTDL_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 547                                         strerror(errno));
 548                 }
 549                 lprintf(CTDL_INFO, "Changing uid to %ld\n", (long)UID);
 550                 if (setuid(UID) != 0) {
 551                         lprintf(CTDL_CRIT, "setuid() failed: %s\n", strerror(errno));
 552                 }
 553 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 554                 prctl(PR_SET_DUMPABLE, 1);
 555 #endif
 556         }
 557 }
 558
 559
 560 /*
 561  * print the actual stack frame.
 562  */
 563 void wc_backtrace(void)
 564 {
 565 #ifdef HAVE_BACKTRACE
 566         void *stack_frames[50];
 567         size_t size, i;
 568         char **strings;
 569
 570
 571         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 572         strings = backtrace_symbols(stack_frames, size);
 573         for (i = 0; i < size; i++) {
 574                 if (strings != NULL)
 575                         lprintf(1, "%s\n", strings[i]);
 576                 else
 577                         lprintf(1, "%p\n", stack_frames[i]);
 578         }
 579         free(strings);
 580 #endif
 581 }