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