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                         --num_threads_executing;
 159                         ssock = accept(msock, NULL, 0);
 160                         ++num_threads_executing;
 161                         lprintf(9, "Thread %u woke up, accept() returned %d %s\n",
 162                                 pthread_self(),
 163                                 ssock,
 164                                 ((ssock >= 0) ? "" : strerror(errno))
 165                         );
 166                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 167
 168                 if ((msock == -1)||(time_to_die))
 169                 {/* ok, we're going down. */
 170                         int shutdown = 0;
 171
 172                         /* The first thread to get here will have to do the cleanup.
 173                          * Make sure it's really just one.
 174                          */
 175                         begin_critical_section(S_SHUTDOWN);
 176                         if (msock == -1)
 177                         {
 178                                 msock = -2;
 179                                 shutdown = 1;
 180                         }
 181                         end_critical_section(S_SHUTDOWN);
 182                         if (shutdown == 1)
 183                         {/* we're the one to cleanup the mess. */
 184                                 http_destroy_modules(&Hdr);
 185                                 lprintf(2, "I'm master shutdown: tagging sessions to be killed.\n");
 186                                 shutdown_sessions();
 187                                 lprintf(2, "master shutdown: waiting for others\n");
 188                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 189                                 lprintf(2, "master shutdown: cleaning up sessions\n");
 190                                 do_housekeeping();
 191                                 lprintf(2, "master shutdown: cleaning up libical\n");
 192
 193                                 ShutDownWebcit();
 194
 195                                 lprintf(2, "master shutdown exiting!.\n");
 196                                 exit(0);
 197                         }
 198                         break;
 199                 }
 200                 if (ssock < 0 ) continue;
 201
 202                 /* Now do something. */
 203                 if (msock < 0) {
 204                         if (ssock > 0) close (ssock);
 205                         lprintf(2, "in between.");
 206                         pthread_exit(NULL);
 207                 } else {
 208                         /* Got it? do some real work! */
 209                         /* Set the SO_REUSEADDR socket option */
 210                         i = 1;
 211                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 212
 213                         /* If we are an HTTPS server, go crypto now. */
 214 #ifdef HAVE_OPENSSL
 215                         if (is_https) {
 216                                 if (starttls(ssock) != 0) {
 217                                         fail_this_transaction = 1;
 218                                         close(ssock);
 219                                 }
 220                         }
 221                         else
 222 #endif
 223                         {
 224                                 int fdflags;
 225                                 fdflags = fcntl(ssock, F_GETFL);
 226                                 if (fdflags < 0)
 227                                         lprintf(1, "unable to get server socket flags! %s \n",
 228                                                 strerror(errno));
 229                                 fdflags = fdflags | O_NONBLOCK;
 230                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 231                                         lprintf(1, "unable to set server socket nonblocking flags! %s \n",
 232                                                 strerror(errno));
 233                         }
 234
 235                         if (fail_this_transaction == 0) {
 236                                 Hdr.http_sock = ssock;
 237
 238                                 /* Perform an HTTP transaction... */
 239                                 context_loop(&Hdr);
 240
 241                                 /* Shut down SSL/TLS if required... */
 242 #ifdef HAVE_OPENSSL
 243                                 if (is_https) {
 244                                         endtls();
 245                                 }
 246 #endif
 247
 248                                 /* ...and close the socket. */
 249                                 if (Hdr.http_sock > 0) {
 250                                         lingering_close(ssock);
 251                                 }
 252                                 http_detach_modules(&Hdr);
 253
 254                         }
 255
 256                 }
 257
 258         } while (!time_to_die);
 259
 260         http_destroy_modules(&Hdr);
 261         lprintf (1, "bye\n");
 262         pthread_exit(NULL);
 263 }
 264
 265 /*
 266  * print log messages
 267  * logs to stderr if loglevel is lower than the verbosity set at startup
 268  *
 269  * loglevel     level of the message
 270  * format       the printf like format string
 271  * ...          the strings to put into format
 272  */
 273 int lprintf(int loglevel, const char *format, ...)
 274 {
 275         va_list ap;
 276
 277         if (loglevel <= verbosity) {
 278                 va_start(ap, format);
 279                 vfprintf(stderr, format, ap);
 280                 va_end(ap);
 281                 fflush(stderr);
 282         }
 283         return 1;
 284 }
 285
 286 /*
 287  * Shut us down the regular way.
 288  * signum is the signal we want to forward
 289  */
 290 pid_t current_child;
 291 void graceful_shutdown_watcher(int signum) {
 292         lprintf (1, "bye; shutting down watcher.");
 293         kill(current_child, signum);
 294         if (signum != SIGHUP)
 295                 exit(0);
 296 }
 297
 298
 299
 300
 301 /*
 302  * Shut us down the regular way.
 303  * signum is the signal we want to forward
 304  */
 305 pid_t current_child;
 306 void graceful_shutdown(int signum) {
 307         FILE *FD;
 308         int fd;
 309
 310         lprintf (1, "WebCit is being shut down on signal %d.\n", signum);
 311         fd = msock;
 312         msock = -1;
 313         time_to_die = 1;
 314         FD=fdopen(fd, "a+");
 315         fflush (FD);
 316         fclose (FD);
 317         close(fd);
 318 }
 319
 320
 321 /*
 322  * Start running as a daemon.
 323  */
 324 void start_daemon(char *pid_file)
 325 {
 326         int status = 0;
 327         pid_t child = 0;
 328         FILE *fp;
 329         int do_restart = 0;
 330         int rv;
 331         FILE *rvfp = NULL;
 332
 333         current_child = 0;
 334
 335         /* Close stdin/stdout/stderr and replace them with /dev/null.
 336          * We don't just call close() because we don't want these fd's
 337          * to be reused for other files.
 338          */
 339         rv = chdir("/");
 340
 341         signal(SIGHUP, SIG_IGN);
 342         signal(SIGINT, SIG_IGN);
 343         signal(SIGQUIT, SIG_IGN);
 344
 345         child = fork();
 346         if (child != 0) {
 347                 exit(0);
 348         }
 349
 350         setsid();
 351         umask(0);
 352         rvfp = freopen("/dev/null", "r", stdin);
 353         rvfp = freopen("/dev/null", "w", stdout);
 354         rvfp = freopen("/dev/null", "w", stderr);
 355         signal(SIGTERM, graceful_shutdown_watcher);
 356         signal(SIGHUP, graceful_shutdown_watcher);
 357
 358         do {
 359                 current_child = fork();
 360
 361
 362                 if (current_child < 0) {
 363                         perror("fork");
 364                         ShutDownLibCitadel ();
 365                         exit(errno);
 366                 }
 367
 368                 else if (current_child == 0) {  /* child process */
 369                         signal(SIGHUP, graceful_shutdown);
 370
 371                         return; /* continue starting webcit. */
 372                 }
 373                 else { /* watcher process */
 374                         if (pid_file) {
 375                                 fp = fopen(pid_file, "w");
 376                                 if (fp != NULL) {
 377                                         fprintf(fp, "%d\n", getpid());
 378                                         fclose(fp);
 379                                 }
 380                         }
 381                         waitpid(current_child, &status, 0);
 382                 }
 383
 384                 do_restart = 0;
 385
 386                 /* Did the main process exit with an actual exit code? */
 387                 if (WIFEXITED(status)) {
 388
 389                         /* Exit code 0 means the watcher should exit */
 390                         if (WEXITSTATUS(status) == 0) {
 391                                 do_restart = 0;
 392                         }
 393
 394                         /* Exit code 101-109 means the watcher should exit */
 395                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 396                                 do_restart = 0;
 397                         }
 398
 399                         /* Any other exit code means we should restart. */
 400                         else {
 401                                 do_restart = 1;
 402                         }
 403                 }
 404
 405                 /* Any other type of termination (signals, etc.) should also restart. */
 406                 else {
 407                         do_restart = 1;
 408                 }
 409
 410         } while (do_restart);
 411
 412         if (pid_file) {
 413                 unlink(pid_file);
 414         }
 415         ShutDownLibCitadel ();
 416         exit(WEXITSTATUS(status));
 417 }
 418
 419 /*
 420  * Spawn an additional worker thread into the pool.
 421  */
 422 void spawn_another_worker_thread()
 423 {
 424         pthread_t SessThread;   /* Thread descriptor */
 425         pthread_attr_t attr;    /* Thread attributes */
 426         int ret;
 427
 428         lprintf(3, "Creating a new thread.\n");
 429
 430         ++num_threads_existing;
 431         ++num_threads_executing;
 432
 433         /* set attributes for the new thread */
 434         pthread_attr_init(&attr);
 435         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 436
 437         /*
 438          * Our per-thread stacks need to be bigger than the default size,
 439          * otherwise the MIME parser crashes on FreeBSD.
 440          */
 441         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 442                 lprintf(1, "pthread_attr_setstacksize: %s\n",
 443                         strerror(ret));
 444                 pthread_attr_destroy(&attr);
 445         }
 446
 447         /* now create the thread */
 448         if (pthread_create(&SessThread, &attr,
 449                            (void *(*)(void *)) worker_entry, NULL)
 450             != 0) {
 451                 lprintf(1, "Can't create thread: %s\n", strerror(errno));
 452         }
 453
 454         /* free up the attributes */
 455         pthread_attr_destroy(&attr);
 456 }
 457
 458
 459 void
 460 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 461 {
 462         char dirbuffer[PATH_MAX]="";
 463         /* calculate all our path on a central place */
 464     /* where to keep our config */
 465
 466 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 467         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 468                          (home&!relh)?webcitdir:basedir, \
 469              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 470              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 471                          relhome, \
 472              (relhome[0]!='\0')?"/":"",\
 473                          dirbuffer,\
 474                          (dirbuffer[0]!='\0')?"/":"");
 475         basedir=RUNDIR;
 476         COMPUTE_DIRECTORY(socket_dir);
 477         basedir=WWWDIR "/static";
 478         COMPUTE_DIRECTORY(static_dir);
 479         basedir=WWWDIR "/static/icons";
 480         COMPUTE_DIRECTORY(static_icon_dir);
 481         basedir=WWWDIR "/static.local";
 482         COMPUTE_DIRECTORY(static_local_dir);
 483         StripSlashes(static_dir, 1);
 484         StripSlashes(static_icon_dir, 1);
 485         StripSlashes(static_local_dir, 1);
 486
 487         snprintf(file_crpt_file_key,
 488                  sizeof file_crpt_file_key,
 489                  "%s/citadel.key",
 490                  ctdl_key_dir);
 491         snprintf(file_crpt_file_csr,
 492                  sizeof file_crpt_file_csr,
 493                  "%s/citadel.csr",
 494                  ctdl_key_dir);
 495         snprintf(file_crpt_file_cer,
 496                  sizeof file_crpt_file_cer,
 497                  "%s/citadel.cer",
 498                  ctdl_key_dir);
 499
 500         /* we should go somewhere we can leave our coredump, if enabled... */
 501         lprintf(9, "Changing directory to %s\n", socket_dir);
 502         if (chdir(webcitdir) != 0) {
 503                 perror("chdir");
 504         }
 505 }
 506 void drop_root(uid_t UID)
 507 {
 508         struct passwd pw, *pwp = NULL;
 509
 510         /*
 511          * Now that we've bound the sockets, change to the Citadel user id and its
 512          * corresponding group ids
 513          */
 514         if (UID != -1) {
 515
 516 #ifdef HAVE_GETPWUID_R
 517 #ifdef SOLARIS_GETPWUID
 518                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 519 #else // SOLARIS_GETPWUID
 520                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 521 #endif // SOLARIS_GETPWUID
 522 #else // HAVE_GETPWUID_R
 523                 pwp = NULL;
 524 #endif // HAVE_GETPWUID_R
 525
 526                 if (pwp == NULL)
 527                         lprintf(CTDL_CRIT, "WARNING: getpwuid(%ld): %s\n"
 528                                 "Group IDs will be incorrect.\n", UID,
 529                                 strerror(errno));
 530                 else {
 531                         initgroups(pw.pw_name, pw.pw_gid);
 532                         if (setgid(pw.pw_gid))
 533                                 lprintf(CTDL_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 534                                         strerror(errno));
 535                 }
 536                 lprintf(CTDL_INFO, "Changing uid to %ld\n", (long)UID);
 537                 if (setuid(UID) != 0) {
 538                         lprintf(CTDL_CRIT, "setuid() failed: %s\n", strerror(errno));
 539                 }
 540 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 541                 prctl(PR_SET_DUMPABLE, 1);
 542 #endif
 543         }
 544 }
 545
 546
 547 /*
 548  * print the actual stack frame.
 549  */
 550 void wc_backtrace(void)
 551 {
 552 #ifdef HAVE_BACKTRACE
 553         void *stack_frames[50];
 554         size_t size, i;
 555         char **strings;
 556
 557
 558         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 559         strings = backtrace_symbols(stack_frames, size);
 560         for (i = 0; i < size; i++) {
 561                 if (strings != NULL)
 562                         lprintf(1, "%s\n", strings[i]);
 563                 else
 564                         lprintf(1, "%p\n", stack_frames[i]);
 565         }
 566         free(strings);
 567 #endif
 568 }