webcit/sysdep.c

   1 /*
   2  * WebCit "system dependent" code.
   3  *
   4  * Copyright (c) 1996-2012 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, version 3.
   8  *
   9  *
  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  *
  17  *
  18  *
  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
  83 extern void *context_loop(ParsedHttpHdrs *Hdr);
  84 extern void *housekeeping_loop(void);
  85 extern void do_housekeeping(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 int ExitPipe[2];
 104
 105 void InitialiseSemaphores(void)
 106 {
 107         int i;
 108
 109         /* Set up a bunch of semaphores to be used for critical sections */
 110         for (i=0; i<MAX_SEMAPHORES; ++i) {
 111                 pthread_mutex_init(&Critters[i], NULL);
 112         }
 113
 114         if (pipe(ExitPipe))
 115         {
 116                 syslog(2, "Failed to open exit pipe: %d [%s]\n",
 117                        errno,
 118                        strerror(errno));
 119
 120                 exit(-1);
 121         }
 122 }
 123
 124 /*
 125  * Obtain a semaphore lock to begin a critical section.
 126  */
 127 void begin_critical_section(int which_one)
 128 {
 129         pthread_mutex_lock(&Critters[which_one]);
 130 }
 131
 132 /*
 133  * Release a semaphore lock to end a critical section.
 134  */
 135 void end_critical_section(int which_one)
 136 {
 137         pthread_mutex_unlock(&Critters[which_one]);
 138 }
 139
 140
 141 void ShutDownWebcit(void)
 142 {
 143         free_zone_directory ();
 144         icaltimezone_release_zone_tab ();
 145         icalmemory_free_ring ();
 146         ShutDownLibCitadel ();
 147         shutdown_modules ();
 148 #ifdef HAVE_OPENSSL
 149         if (is_https) {
 150                 shutdown_ssl();
 151         }
 152 #endif
 153 }
 154
 155 /*
 156  * Entry point for worker threads
 157  */
 158 void worker_entry(void)
 159 {
 160         int ssock;
 161         int i = 0;
 162         int fail_this_transaction = 0;
 163         ParsedHttpHdrs Hdr;
 164
 165         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 166         Hdr.HR.eReqType = eGET;
 167         http_new_modules(&Hdr);
 168
 169         do {
 170                 /* Each worker thread blocks on accept() while waiting for something to do. */
 171                 fail_this_transaction = 0;
 172                 ssock = -1;
 173                 errno = EAGAIN;
 174                 do {
 175                         fd_set wset;
 176                         --num_threads_executing;
 177                         FD_ZERO(&wset);
 178                         FD_SET(msock, &wset);
 179                         FD_SET(ExitPipe[1], &wset);
 180
 181                         select(msock + 1, NULL, &wset, NULL, NULL);
 182                         if (time_to_die)
 183                                 break;
 184
 185                         ssock = accept(msock, NULL, 0);
 186                         ++num_threads_executing;
 187                         if (ssock < 0) fail_this_transaction = 1;
 188                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 189
 190                 if ((msock == -1)||(time_to_die))
 191                 {/* ok, we're going down. */
 192                         int shutdown = 0;
 193
 194                         /* The first thread to get here will have to do the cleanup.
 195                          * Make sure it's really just one.
 196                          */
 197                         begin_critical_section(S_SHUTDOWN);
 198                         if (msock == -1)
 199                         {
 200                                 msock = -2;
 201                                 shutdown = 1;
 202                         }
 203                         end_critical_section(S_SHUTDOWN);
 204                         if (shutdown == 1)
 205                         {/* we're the one to cleanup the mess. */
 206                                 http_destroy_modules(&Hdr);
 207                                 syslog(2, "I'm master shutdown: tagging sessions to be killed.\n");
 208                                 shutdown_sessions();
 209                                 syslog(2, "master shutdown: waiting for others\n");
 210                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 211                                 syslog(2, "master shutdown: cleaning up sessions\n");
 212                                 do_housekeeping();
 213                                 syslog(2, "master shutdown: cleaning up libical\n");
 214
 215                                 ShutDownWebcit();
 216
 217                                 syslog(2, "master shutdown exiting.\n");
 218                                 exit(0);
 219                         }
 220                         break;
 221                 }
 222                 if (ssock < 0 ) continue;
 223
 224                 check_thread_pool_size();
 225
 226                 /* Now do something. */
 227                 if (msock < 0) {
 228                         if (ssock > 0) close (ssock);
 229                         syslog(2, "in between.");
 230                         pthread_exit(NULL);
 231                 } else {
 232                         /* Got it? do some real work! */
 233                         /* Set the SO_REUSEADDR socket option */
 234                         i = 1;
 235                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 236
 237                         /* If we are an HTTPS server, go crypto now. */
 238 #ifdef HAVE_OPENSSL
 239                         if (is_https) {
 240                                 if (starttls(ssock) != 0) {
 241                                         fail_this_transaction = 1;
 242                                         close(ssock);
 243                                 }
 244                         }
 245                         else
 246 #endif
 247                         {
 248                                 int fdflags;
 249                                 fdflags = fcntl(ssock, F_GETFL);
 250                                 if (fdflags < 0)
 251                                         syslog(1, "unable to get server socket flags! %s \n",
 252                                                 strerror(errno));
 253                                 fdflags = fdflags | O_NONBLOCK;
 254                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 255                                         syslog(1, "unable to set server socket nonblocking flags! %s \n",
 256                                                 strerror(errno));
 257                         }
 258
 259                         if (fail_this_transaction == 0) {
 260                                 Hdr.http_sock = ssock;
 261
 262                                 /* Perform an HTTP transaction... */
 263                                 context_loop(&Hdr);
 264
 265                                 /* Shut down SSL/TLS if required... */
 266 #ifdef HAVE_OPENSSL
 267                                 if (is_https) {
 268                                         endtls();
 269                                 }
 270 #endif
 271
 272                                 /* ...and close the socket. */
 273                                 if (Hdr.http_sock > 0) {
 274                                         lingering_close(ssock);
 275                                 }
 276                                 http_detach_modules(&Hdr);
 277
 278                         }
 279
 280                 }
 281
 282         } while (!time_to_die);
 283
 284         http_destroy_modules(&Hdr);
 285         syslog(1, "Thread exiting.\n");
 286         pthread_exit(NULL);
 287 }
 288
 289
 290 /*
 291  * Shut us down the regular way.
 292  * signum is the signal we want to forward
 293  */
 294 pid_t current_child;
 295 void graceful_shutdown_watcher(int signum) {
 296         syslog(1, "Watcher thread exiting.\n");
 297         write(ExitPipe[0], HKEY("                              "));
 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         syslog(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         write(ExitPipe[0], HKEY("                              "));
 322 }
 323
 324
 325 /*
 326  * Start running as a daemon.
 327  */
 328 void start_daemon(char *pid_file)
 329 {
 330         int status = 0;
 331         pid_t child = 0;
 332         FILE *fp;
 333         int do_restart = 0;
 334
 335         current_child = 0;
 336
 337         /* Close stdin/stdout/stderr and replace them with /dev/null.
 338          * We don't just call close() because we don't want these fd's
 339          * to be reused for other files.
 340          */
 341         chdir("/");
 342
 343         signal(SIGHUP, SIG_IGN);
 344         signal(SIGINT, SIG_IGN);
 345         signal(SIGQUIT, SIG_IGN);
 346
 347         child = fork();
 348         if (child != 0) {
 349                 exit(0);
 350         }
 351
 352         setsid();
 353         umask(0);
 354         freopen("/dev/null", "r", stdin);
 355         freopen("/dev/null", "w", stdout);
 356         freopen("/dev/null", "w", stderr);
 357         signal(SIGTERM, graceful_shutdown_watcher);
 358         signal(SIGHUP, graceful_shutdown_watcher);
 359
 360         do {
 361                 current_child = fork();
 362
 363
 364                 if (current_child < 0) {
 365                         perror("fork");
 366                         ShutDownLibCitadel ();
 367                         exit(errno);
 368                 }
 369
 370                 else if (current_child == 0) {  /* child process */
 371                         signal(SIGHUP, graceful_shutdown);
 372
 373                         return; /* continue starting webcit. */
 374                 }
 375                 else { /* watcher process */
 376                         if (pid_file) {
 377                                 fp = fopen(pid_file, "w");
 378                                 if (fp != NULL) {
 379                                         fprintf(fp, "%d\n", getpid());
 380                                         fclose(fp);
 381                                 }
 382                         }
 383                         waitpid(current_child, &status, 0);
 384                 }
 385
 386                 do_restart = 0;
 387
 388                 /* Did the main process exit with an actual exit code? */
 389                 if (WIFEXITED(status)) {
 390
 391                         /* Exit code 0 means the watcher should exit */
 392                         if (WEXITSTATUS(status) == 0) {
 393                                 do_restart = 0;
 394                         }
 395
 396                         /* Exit code 101-109 means the watcher should exit */
 397                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 398                                 do_restart = 0;
 399                         }
 400
 401                         /* Any other exit code means we should restart. */
 402                         else {
 403                                 do_restart = 1;
 404                         }
 405                 }
 406
 407                 /* Any other type of termination (signals, etc.) should also restart. */
 408                 else {
 409                         do_restart = 1;
 410                 }
 411
 412         } while (do_restart);
 413
 414         if (pid_file) {
 415                 unlink(pid_file);
 416         }
 417         ShutDownLibCitadel ();
 418         exit(WEXITSTATUS(status));
 419 }
 420
 421
 422 /*
 423  * Spawn an additional worker thread into the pool.
 424  */
 425 void spawn_another_worker_thread()
 426 {
 427         pthread_t SessThread;   /* Thread descriptor */
 428         pthread_attr_t attr;    /* Thread attributes */
 429         int ret;
 430
 431         ++num_threads_existing;
 432         ++num_threads_executing;
 433
 434         /* set attributes for the new thread */
 435         pthread_attr_init(&attr);
 436         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 437
 438         /*
 439          * Our per-thread stacks need to be bigger than the default size,
 440          * otherwise the MIME parser crashes on FreeBSD.
 441          */
 442         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 443                 syslog(1, "pthread_attr_setstacksize: %s\n", strerror(ret));
 444                 pthread_attr_destroy(&attr);
 445         }
 446
 447         /* now create the thread */
 448         if (pthread_create(&SessThread, &attr, (void *(*)(void *)) worker_entry, NULL) != 0) {
 449                 syslog(1, "Can't create thread: %s\n", strerror(errno));
 450         }
 451
 452         /* free up the attributes */
 453         pthread_attr_destroy(&attr);
 454 }
 455
 456
 457 void
 458 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 459 {
 460         char dirbuffer[PATH_MAX]="";
 461         /* calculate all our path on a central place */
 462     /* where to keep our config */
 463
 464 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 465         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 466                          (home&!relh)?webcitdir:basedir, \
 467              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 468              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 469                          relhome, \
 470              (relhome[0]!='\0')?"/":"",\
 471                          dirbuffer,\
 472                          (dirbuffer[0]!='\0')?"/":"");
 473         basedir=RUNDIR;
 474         COMPUTE_DIRECTORY(socket_dir);
 475         basedir=WWWDIR "/static";
 476         COMPUTE_DIRECTORY(static_dir);
 477         basedir=WWWDIR "/static/icons";
 478         COMPUTE_DIRECTORY(static_icon_dir);
 479         basedir=WWWDIR "/static.local";
 480         COMPUTE_DIRECTORY(static_local_dir);
 481         StripSlashes(static_dir, 1);
 482         StripSlashes(static_icon_dir, 1);
 483         StripSlashes(static_local_dir, 1);
 484
 485         snprintf(file_crpt_file_key,
 486                  sizeof file_crpt_file_key,
 487                  "%s/citadel.key",
 488                  ctdl_key_dir);
 489         snprintf(file_crpt_file_csr,
 490                  sizeof file_crpt_file_csr,
 491                  "%s/citadel.csr",
 492                  ctdl_key_dir);
 493         snprintf(file_crpt_file_cer,
 494                  sizeof file_crpt_file_cer,
 495                  "%s/citadel.cer",
 496                  ctdl_key_dir);
 497
 498         /* we should go somewhere we can leave our coredump, if enabled... */
 499         syslog(9, "Changing directory to %s\n", socket_dir);
 500         if (chdir(webcitdir) != 0) {
 501                 perror("chdir");
 502         }
 503 }
 504
 505 void drop_root(uid_t UID)
 506 {
 507         struct passwd pw, *pwp = NULL;
 508
 509         /*
 510          * Now that we've bound the sockets, change to the Citadel user id and its
 511          * corresponding group ids
 512          */
 513         if (UID != -1) {
 514
 515 #ifdef HAVE_GETPWUID_R
 516 #ifdef SOLARIS_GETPWUID
 517                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 518 #else /* SOLARIS_GETPWUID */
 519                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 520 #endif /* SOLARIS_GETPWUID */
 521 #else /* HAVE_GETPWUID_R */
 522                 pwp = NULL;
 523 #endif /* HAVE_GETPWUID_R */
 524
 525                 if (pwp == NULL)
 526                         syslog(LOG_CRIT, "WARNING: getpwuid(%d): %s\n"
 527                                 "Group IDs will be incorrect.\n", UID,
 528                                 strerror(errno));
 529                 else {
 530                         initgroups(pw.pw_name, pw.pw_gid);
 531                         if (setgid(pw.pw_gid))
 532                                 syslog(LOG_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 533                                         strerror(errno));
 534                 }
 535                 syslog(LOG_INFO, "Changing uid to %ld\n", (long)UID);
 536                 if (setuid(UID) != 0) {
 537                         syslog(LOG_CRIT, "setuid() failed: %s\n", strerror(errno));
 538                 }
 539 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 540                 prctl(PR_SET_DUMPABLE, 1);
 541 #endif
 542         }
 543 }
 544
 545
 546 /*
 547  * print the actual stack frame.
 548  */
 549 void wc_backtrace(void)
 550 {
 551 #ifdef HAVE_BACKTRACE
 552         void *stack_frames[50];
 553         size_t size, i;
 554         char **strings;
 555
 556
 557         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 558         strings = backtrace_symbols(stack_frames, size);
 559         for (i = 0; i < size; i++) {
 560                 if (strings != NULL)
 561                         syslog(1, "%s\n", strings[i]);
 562                 else
 563                         syslog(1, "%p\n", stack_frames[i]);
 564         }
 565         free(strings);
 566 #endif
 567 }