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         ParsedHttpHdrs Hdr;
 147
 148         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 149         Hdr.HR.eReqType = eGET;
 150         http_new_modules(&Hdr);
 151
 152         do {
 153                 /* Only one thread can accept at a time */
 154                 fail_this_transaction = 0;
 155                 ssock = -1;
 156                 errno = EAGAIN;
 157                 do {
 158                         ssock = accept(msock, NULL, 0);
 159                         lprintf(9, "\033[3%dmthread %u woke up, accept() returned %d %s\033[0m\n",
 160                                 ((pthread_self() % 6) + 1),
 161                                 pthread_self(),
 162                                 ssock,
 163                                 ((ssock >= 0) ? "" : strerror(errno))
 164                         );
 165                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 166
 167                 if ((msock == -1)||(time_to_die))
 168                 {/* ok, we're going down. */
 169                         int shutdown = 0;
 170
 171                         /* the first to come here will have to do the cleanup.
 172                          * make shure its realy just one.
 173                          */
 174                         begin_critical_section(S_SHUTDOWN);
 175                         if (msock == -1)
 176                         {
 177                                 msock = -2;
 178                                 shutdown = 1;
 179                         }
 180                         end_critical_section(S_SHUTDOWN);
 181                         if (shutdown == 1)
 182                         {/* we're the one to cleanup the mess. */
 183                                 http_destroy_modules(&Hdr);
 184                                 lprintf(2, "I'm master shutdown: tagging sessions to be killed.\n");
 185                                 shutdown_sessions();
 186                                 lprintf(2, "master shutdown: waiting for others\n");
 187                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 188                                 lprintf(2, "master shutdown: cleaning up sessions\n");
 189                                 do_housekeeping();
 190                                 lprintf(2, "master shutdown: cleaning up libical\n");
 191
 192                                 ShutDownWebcit();
 193
 194                                 lprintf(2, "master shutdown exiting!.\n");
 195                                 exit(0);
 196                         }
 197                         break;
 198                 }
 199                 if (ssock < 0 ) continue;
 200
 201                 if (msock < 0) {
 202                         if (ssock > 0) close (ssock);
 203                         lprintf(2, "inbetween.");
 204                         pthread_exit(NULL);
 205                 } else { /* Got it? do some real work! */
 206                         /* Set the SO_REUSEADDR socket option */
 207                         i = 1;
 208                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR,
 209                                    &i, sizeof(i));
 210
 211                         /* If we are an HTTPS server, go crypto now. */
 212 #ifdef HAVE_OPENSSL
 213                         if (is_https) {
 214                                 if (starttls(ssock) != 0) {
 215                                         fail_this_transaction = 1;
 216                                         close(ssock);
 217                                 }
 218                         }
 219                         else
 220 #endif
 221                         {
 222                                 int fdflags;
 223                                 fdflags = fcntl(ssock, F_GETFL);
 224                                 if (fdflags < 0)
 225                                         lprintf(1, "unable to get server socket flags! %s \n",
 226                                                 strerror(errno));
 227                                 fdflags = fdflags | O_NONBLOCK;
 228                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 229                                         lprintf(1, "unable to set server socket nonblocking flags! %s \n",
 230                                                 strerror(errno));
 231                         }
 232
 233                         if (fail_this_transaction == 0) {
 234                                 Hdr.http_sock = ssock;
 235
 236                                 /* Perform an HTTP transaction... */
 237                                 context_loop(&Hdr);
 238
 239                                 /* Shut down SSL/TLS if required... */
 240 #ifdef HAVE_OPENSSL
 241                                 if (is_https) {
 242                                         endtls();
 243                                 }
 244 #endif
 245
 246                                 /* ...and close the socket. */
 247                                 if (Hdr.http_sock > 0)
 248                                         lingering_close(ssock);
 249                                 http_detach_modules(&Hdr);
 250
 251                         }
 252
 253                 }
 254
 255         } while (!time_to_die);
 256
 257         http_destroy_modules(&Hdr);
 258         lprintf (1, "bye\n");
 259         pthread_exit(NULL);
 260 }
 261
 262 /*
 263  * print log messages
 264  * logs to stderr if loglevel is lower than the verbosity set at startup
 265  *
 266  * loglevel     level of the message
 267  * format       the printf like format string
 268  * ...          the strings to put into format
 269  */
 270 int lprintf(int loglevel, const char *format, ...)
 271 {
 272         va_list ap;
 273
 274         if (loglevel <= verbosity) {
 275                 va_start(ap, format);
 276                 vfprintf(stderr, format, ap);
 277                 va_end(ap);
 278                 fflush(stderr);
 279         }
 280         return 1;
 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_watcher(int signum) {
 289         lprintf (1, "bye; shutting down watcher.");
 290         kill(current_child, signum);
 291         if (signum != SIGHUP)
 292                 exit(0);
 293 }
 294
 295
 296
 297
 298 /*
 299  * Shut us down the regular way.
 300  * signum is the signal we want to forward
 301  */
 302 pid_t current_child;
 303 void graceful_shutdown(int signum) {
 304         FILE *FD;
 305         int fd;
 306
 307         lprintf (1, "WebCit is being shut down on signal %d.\n", signum);
 308         fd = msock;
 309         msock = -1;
 310         time_to_die = 1;
 311         FD=fdopen(fd, "a+");
 312         fflush (FD);
 313         fclose (FD);
 314         close(fd);
 315 }
 316
 317
 318 /*
 319  * Start running as a daemon.
 320  */
 321 void start_daemon(char *pid_file)
 322 {
 323         int status = 0;
 324         pid_t child = 0;
 325         FILE *fp;
 326         int do_restart = 0;
 327         int rv;
 328         FILE *rvfp = NULL;
 329
 330         current_child = 0;
 331
 332         /* Close stdin/stdout/stderr and replace them with /dev/null.
 333          * We don't just call close() because we don't want these fd's
 334          * to be reused for other files.
 335          */
 336         rv = chdir("/");
 337
 338         signal(SIGHUP, SIG_IGN);
 339         signal(SIGINT, SIG_IGN);
 340         signal(SIGQUIT, SIG_IGN);
 341
 342         child = fork();
 343         if (child != 0) {
 344                 exit(0);
 345         }
 346
 347         setsid();
 348         umask(0);
 349         rvfp = freopen("/dev/null", "r", stdin);
 350         rvfp = freopen("/dev/null", "w", stdout);
 351         rvfp = freopen("/dev/null", "w", stderr);
 352         signal(SIGTERM, graceful_shutdown_watcher);
 353         signal(SIGHUP, graceful_shutdown_watcher);
 354
 355         do {
 356                 current_child = fork();
 357
 358
 359                 if (current_child < 0) {
 360                         perror("fork");
 361                         ShutDownLibCitadel ();
 362                         exit(errno);
 363                 }
 364
 365                 else if (current_child == 0) {  /* child process */
 366                         signal(SIGHUP, graceful_shutdown);
 367
 368                         return; /* continue starting webcit. */
 369                 }
 370                 else { /* watcher process */
 371                         if (pid_file) {
 372                                 fp = fopen(pid_file, "w");
 373                                 if (fp != NULL) {
 374                                         fprintf(fp, "%d\n", getpid());
 375                                         fclose(fp);
 376                                 }
 377                         }
 378                         waitpid(current_child, &status, 0);
 379                 }
 380
 381                 do_restart = 0;
 382
 383                 /* Did the main process exit with an actual exit code? */
 384                 if (WIFEXITED(status)) {
 385
 386                         /* Exit code 0 means the watcher should exit */
 387                         if (WEXITSTATUS(status) == 0) {
 388                                 do_restart = 0;
 389                         }
 390
 391                         /* Exit code 101-109 means the watcher should exit */
 392                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 393                                 do_restart = 0;
 394                         }
 395
 396                         /* Any other exit code means we should restart. */
 397                         else {
 398                                 do_restart = 1;
 399                         }
 400                 }
 401
 402                 /* Any other type of termination (signals, etc.) should also restart. */
 403                 else {
 404                         do_restart = 1;
 405                 }
 406
 407         } while (do_restart);
 408
 409         if (pid_file) {
 410                 unlink(pid_file);
 411         }
 412         ShutDownLibCitadel ();
 413         exit(WEXITSTATUS(status));
 414 }
 415
 416 /*
 417  * Spawn an additional worker thread into the pool.
 418  */
 419 void spawn_another_worker_thread()
 420 {
 421         pthread_t SessThread;   /* Thread descriptor */
 422         pthread_attr_t attr;    /* Thread attributes */
 423         int ret;
 424
 425         lprintf(3, "Creating a new thread.  Pool size is now %d\n", ++num_threads);
 426
 427         /* set attributes for the new thread */
 428         pthread_attr_init(&attr);
 429         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 430
 431         /*
 432          * Our per-thread stacks need to be bigger than the default size,
 433          * otherwise the MIME parser crashes on FreeBSD.
 434          */
 435         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 436                 lprintf(1, "pthread_attr_setstacksize: %s\n",
 437                         strerror(ret));
 438                 pthread_attr_destroy(&attr);
 439         }
 440
 441         /* now create the thread */
 442         if (pthread_create(&SessThread, &attr,
 443                            (void *(*)(void *)) worker_entry, NULL)
 444             != 0) {
 445                 lprintf(1, "Can't create thread: %s\n", strerror(errno));
 446         }
 447
 448         /* free up the attributes */
 449         pthread_attr_destroy(&attr);
 450 }
 451
 452
 453 void
 454 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 455 {
 456         char dirbuffer[PATH_MAX]="";
 457         /* calculate all our path on a central place */
 458     /* where to keep our config */
 459
 460 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 461         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 462                          (home&!relh)?webcitdir:basedir, \
 463              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 464              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 465                          relhome, \
 466              (relhome[0]!='\0')?"/":"",\
 467                          dirbuffer,\
 468                          (dirbuffer[0]!='\0')?"/":"");
 469         basedir=RUNDIR;
 470         COMPUTE_DIRECTORY(socket_dir);
 471         basedir=WWWDIR "/static";
 472         COMPUTE_DIRECTORY(static_dir);
 473         basedir=WWWDIR "/static/icons";
 474         COMPUTE_DIRECTORY(static_icon_dir);
 475         basedir=WWWDIR "/static.local";
 476         COMPUTE_DIRECTORY(static_local_dir);
 477         StripSlashes(static_dir, 1);
 478         StripSlashes(static_icon_dir, 1);
 479         StripSlashes(static_local_dir, 1);
 480
 481         snprintf(file_crpt_file_key,
 482                  sizeof file_crpt_file_key,
 483                  "%s/citadel.key",
 484                  ctdl_key_dir);
 485         snprintf(file_crpt_file_csr,
 486                  sizeof file_crpt_file_csr,
 487                  "%s/citadel.csr",
 488                  ctdl_key_dir);
 489         snprintf(file_crpt_file_cer,
 490                  sizeof file_crpt_file_cer,
 491                  "%s/citadel.cer",
 492                  ctdl_key_dir);
 493
 494         /* we should go somewhere we can leave our coredump, if enabled... */
 495         lprintf(9, "Changing directory to %s\n", socket_dir);
 496         if (chdir(webcitdir) != 0) {
 497                 perror("chdir");
 498         }
 499 }
 500 void drop_root(uid_t UID)
 501 {
 502         struct passwd pw, *pwp = NULL;
 503
 504         /*
 505          * Now that we've bound the sockets, change to the Citadel user id and its
 506          * corresponding group ids
 507          */
 508         if (UID != -1) {
 509
 510 #ifdef HAVE_GETPWUID_R
 511 #ifdef SOLARIS_GETPWUID
 512                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 513 #else // SOLARIS_GETPWUID
 514                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 515 #endif // SOLARIS_GETPWUID
 516 #else // HAVE_GETPWUID_R
 517                 pwp = NULL;
 518 #endif // HAVE_GETPWUID_R
 519
 520                 if (pwp == NULL)
 521                         lprintf(CTDL_CRIT, "WARNING: getpwuid(%ld): %s\n"
 522                                 "Group IDs will be incorrect.\n", UID,
 523                                 strerror(errno));
 524                 else {
 525                         initgroups(pw.pw_name, pw.pw_gid);
 526                         if (setgid(pw.pw_gid))
 527                                 lprintf(CTDL_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 528                                         strerror(errno));
 529                 }
 530                 lprintf(CTDL_INFO, "Changing uid to %ld\n", (long)UID);
 531                 if (setuid(UID) != 0) {
 532                         lprintf(CTDL_CRIT, "setuid() failed: %s\n", strerror(errno));
 533                 }
 534 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 535                 prctl(PR_SET_DUMPABLE, 1);
 536 #endif
 537         }
 538 }
 539
 540
 541 /*
 542  * print the actual stack frame.
 543  */
 544 void wc_backtrace(void)
 545 {
 546 #ifdef HAVE_BACKTRACE
 547         void *stack_frames[50];
 548         size_t size, i;
 549         char **strings;
 550
 551
 552         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 553         strings = backtrace_symbols(stack_frames, size);
 554         for (i = 0; i < size; i++) {
 555                 if (strings != NULL)
 556                         lprintf(1, "%s\n", strings[i]);
 557                 else
 558                         lprintf(1, "%p\n", stack_frames[i]);
 559         }
 560         free(strings);
 561 #endif
 562 }