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  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include "sysdep.h"
  16 #include <stdlib.h>
  17 #include <unistd.h>
  18 #include <stdio.h>
  19 #include <fcntl.h>
  20 #include <ctype.h>
  21 #include <signal.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <sys/wait.h>
  25 #include <sys/socket.h>
  26 #include <syslog.h>
  27 #include <sys/syslog.h>
  28
  29 #if TIME_WITH_SYS_TIME
  30 # include <sys/time.h>
  31 # include <time.h>
  32 #else
  33 # if HAVE_SYS_TIME_H
  34 #  include <sys/time.h>
  35 # else
  36 #  include <time.h>
  37 # endif
  38 #endif
  39
  40 #include <limits.h>
  41 #include <sys/resource.h>
  42 #include <netinet/in.h>
  43 #include <netinet/tcp.h>
  44 #include <arpa/inet.h>
  45 #include <netdb.h>
  46 #include <sys/un.h>
  47 #include <string.h>
  48 #include <pwd.h>
  49 #include <errno.h>
  50 #include <stdarg.h>
  51 #include <grp.h>
  52 #ifdef HAVE_PTHREAD_H
  53 #include <pthread.h>
  54 #endif
  55 #include "webcit.h"
  56 #include "sysdep.h"
  57
  58 #ifdef HAVE_SYS_SELECT_H
  59 #include <sys/select.h>
  60 #endif
  61
  62 #include "webserver.h"
  63 #include "modules_init.h"
  64 #if HAVE_BACKTRACE
  65 #include <execinfo.h>
  66 #endif
  67
  68 pthread_mutex_t Critters[MAX_SEMAPHORES];       /* Things needing locking */
  69 pthread_key_t MyConKey;                         /* TSD key for MyContext() */
  70 pthread_key_t MyReq;                            /* TSD key for MyReq() */
  71 int msock;                      /* master listening socket */
  72 int time_to_die = 0;            /* Nonzero if server is shutting down */
  73
  74 extern void *context_loop(ParsedHttpHdrs *Hdr);
  75 extern void *housekeeping_loop(void);
  76 extern void do_housekeeping(void);
  77
  78 char ctdl_key_dir[PATH_MAX]=SSL_DIR;
  79 char file_crpt_file_key[PATH_MAX]="";
  80 char file_crpt_file_csr[PATH_MAX]="";
  81 char file_crpt_file_cer[PATH_MAX]="";
  82
  83 const char editor_absolut_dir[PATH_MAX]=EDITORDIR;      /* nailed to what configure gives us. */
  84 char static_dir[PATH_MAX];              /* calculated on startup */
  85 char static_local_dir[PATH_MAX];                /* calculated on startup */
  86 char static_icon_dir[PATH_MAX];          /* where should we find our mime icons? */
  87 char  *static_dirs[]={                          /* needs same sort order as the web mapping */
  88         (char*)static_dir,                      /* our templates on disk */
  89         (char*)static_local_dir,                /* user provided templates disk */
  90         (char*)editor_absolut_dir,              /* the editor on disk */
  91         (char*)static_icon_dir                  /* our icons... */
  92 };
  93
  94 int ExitPipe[2];
  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         if (pipe(ExitPipe))
 106         {
 107                 syslog(LOG_WARNING, "Failed to open exit pipe: %d [%s]\n",
 108                        errno,
 109                        strerror(errno));
 110
 111                 exit(-1);
 112         }
 113 }
 114
 115 /*
 116  * Obtain a semaphore lock to begin a critical section.
 117  */
 118 void begin_critical_section(int which_one)
 119 {
 120         pthread_mutex_lock(&Critters[which_one]);
 121 }
 122
 123 /*
 124  * Release a semaphore lock to end a critical section.
 125  */
 126 void end_critical_section(int which_one)
 127 {
 128         pthread_mutex_unlock(&Critters[which_one]);
 129 }
 130
 131
 132 void ShutDownWebcit(void)
 133 {
 134         free_zone_directory ();
 135         icaltimezone_release_zone_tab ();
 136         icalmemory_free_ring ();
 137         ShutDownLibCitadel ();
 138         shutdown_modules ();
 139 #ifdef HAVE_OPENSSL
 140         if (is_https) {
 141                 shutdown_ssl();
 142         }
 143 #endif
 144 }
 145
 146 /*
 147  * Entry point for worker threads
 148  */
 149 void worker_entry(void)
 150 {
 151         int ssock;
 152         int i = 0;
 153         int fail_this_transaction = 0;
 154         ParsedHttpHdrs Hdr;
 155
 156         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 157         Hdr.HR.eReqType = eGET;
 158         http_new_modules(&Hdr);
 159
 160         do {
 161                 /* Each worker thread blocks on accept() while waiting for something to do. */
 162                 fail_this_transaction = 0;
 163                 ssock = -1;
 164                 errno = EAGAIN;
 165                 do {
 166                         fd_set wset;
 167                         --num_threads_executing;
 168                         FD_ZERO(&wset);
 169                         FD_SET(msock, &wset);
 170                         FD_SET(ExitPipe[1], &wset);
 171
 172                         select(msock + 1, NULL, &wset, NULL, NULL);
 173                         if (time_to_die)
 174                                 break;
 175
 176                         ssock = accept(msock, NULL, 0);
 177                         ++num_threads_executing;
 178                         if (ssock < 0) fail_this_transaction = 1;
 179                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 180
 181                 if ((msock == -1)||(time_to_die))
 182                 {/* ok, we're going down. */
 183                         int shutdown = 0;
 184
 185                         /* The first thread to get here will have to do the cleanup.
 186                          * Make sure it's really just one.
 187                          */
 188                         begin_critical_section(S_SHUTDOWN);
 189                         if (msock == -1)
 190                         {
 191                                 msock = -2;
 192                                 shutdown = 1;
 193                         }
 194                         end_critical_section(S_SHUTDOWN);
 195                         if (shutdown == 1)
 196                         {/* we're the one to cleanup the mess. */
 197                                 http_destroy_modules(&Hdr);
 198                                 syslog(LOG_DEBUG, "I'm master shutdown: tagging sessions to be killed.\n");
 199                                 shutdown_sessions();
 200                                 syslog(LOG_DEBUG, "master shutdown: waiting for others\n");
 201                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 202                                 syslog(LOG_DEBUG, "master shutdown: cleaning up sessions\n");
 203                                 do_housekeeping();
 204                                 syslog(LOG_DEBUG, "master shutdown: cleaning up libical\n");
 205
 206                                 ShutDownWebcit();
 207
 208                                 syslog(LOG_DEBUG, "master shutdown exiting.\n");
 209                                 exit(0);
 210                         }
 211                         break;
 212                 }
 213                 if (ssock < 0 ) continue;
 214
 215                 check_thread_pool_size();
 216
 217                 /* Now do something. */
 218                 if (msock < 0) {
 219                         if (ssock > 0) close (ssock);
 220                         syslog(LOG_DEBUG, "in between.");
 221                         pthread_exit(NULL);
 222                 } else {
 223                         /* Got it? do some real work! */
 224                         /* Set the SO_REUSEADDR socket option */
 225                         i = 1;
 226                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 227
 228                         /* If we are an HTTPS server, go crypto now. */
 229 #ifdef HAVE_OPENSSL
 230                         if (is_https) {
 231                                 if (starttls(ssock) != 0) {
 232                                         fail_this_transaction = 1;
 233                                         close(ssock);
 234                                 }
 235                         }
 236                         else
 237 #endif
 238                         {
 239                                 int fdflags;
 240                                 fdflags = fcntl(ssock, F_GETFL);
 241                                 if (fdflags < 0)
 242                                         syslog(LOG_WARNING, "unable to get server socket flags! %s \n",
 243                                                 strerror(errno));
 244                                 fdflags = fdflags | O_NONBLOCK;
 245                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 246                                         syslog(LOG_WARNING, "unable to set server socket nonblocking flags! %s \n",
 247                                                 strerror(errno));
 248                         }
 249
 250                         if (fail_this_transaction == 0) {
 251                                 Hdr.http_sock = ssock;
 252
 253                                 /* Perform an HTTP transaction... */
 254                                 context_loop(&Hdr);
 255
 256                                 /* Shut down SSL/TLS if required... */
 257 #ifdef HAVE_OPENSSL
 258                                 if (is_https) {
 259                                         endtls();
 260                                 }
 261 #endif
 262
 263                                 /* ...and close the socket. */
 264                                 if (Hdr.http_sock > 0) {
 265                                         lingering_close(ssock);
 266                                 }
 267                                 http_detach_modules(&Hdr);
 268
 269                         }
 270
 271                 }
 272
 273         } while (!time_to_die);
 274
 275         http_destroy_modules(&Hdr);
 276         syslog(LOG_DEBUG, "Thread exiting.\n");
 277         pthread_exit(NULL);
 278 }
 279
 280
 281 /*
 282  * Shut us down the regular way.
 283  * signum is the signal we want to forward
 284  */
 285 pid_t current_child;
 286 void graceful_shutdown_watcher(int signum) {
 287         syslog(LOG_INFO, "Watcher thread exiting.\n");
 288         write(ExitPipe[0], HKEY("                              "));
 289         kill(current_child, signum);
 290         if (signum != SIGHUP)
 291                 exit(0);
 292 }
 293
 294
 295 /*
 296  * Shut us down the regular way.
 297  * signum is the signal we want to forward
 298  */
 299 pid_t current_child;
 300 void graceful_shutdown(int signum) {
 301         FILE *FD;
 302         int fd;
 303
 304         syslog(LOG_INFO, "WebCit is being shut down on signal %d.\n", signum);
 305         fd = msock;
 306         msock = -1;
 307         time_to_die = 1;
 308         FD=fdopen(fd, "a+");
 309         fflush (FD);
 310         fclose (FD);
 311         close(fd);
 312         write(ExitPipe[0], HKEY("                              "));
 313 }
 314
 315
 316 /*
 317  * Start running as a daemon.
 318  */
 319 void start_daemon(char *pid_file)
 320 {
 321         int status = 0;
 322         pid_t child = 0;
 323         FILE *fp;
 324         int do_restart = 0;
 325
 326         current_child = 0;
 327
 328         /* Close stdin/stdout/stderr and replace them with /dev/null.
 329          * We don't just call close() because we don't want these fd's
 330          * to be reused for other files.
 331          */
 332         chdir("/");
 333
 334         signal(SIGHUP, SIG_IGN);
 335         signal(SIGINT, SIG_IGN);
 336         signal(SIGQUIT, SIG_IGN);
 337
 338         child = fork();
 339         if (child != 0) {
 340                 exit(0);
 341         }
 342
 343         setsid();
 344         umask(0);
 345         freopen("/dev/null", "r", stdin);
 346         freopen("/dev/null", "w", stdout);
 347         freopen("/dev/null", "w", stderr);
 348         signal(SIGTERM, graceful_shutdown_watcher);
 349         signal(SIGHUP, graceful_shutdown_watcher);
 350
 351         do {
 352                 current_child = fork();
 353
 354
 355                 if (current_child < 0) {
 356                         perror("fork");
 357                         ShutDownLibCitadel ();
 358                         exit(errno);
 359                 }
 360
 361                 else if (current_child == 0) {  /* child process */
 362                         signal(SIGHUP, graceful_shutdown);
 363
 364                         return; /* continue starting webcit. */
 365                 }
 366                 else { /* watcher process */
 367                         if (pid_file) {
 368                                 fp = fopen(pid_file, "w");
 369                                 if (fp != NULL) {
 370                                         fprintf(fp, "%d\n", getpid());
 371                                         fclose(fp);
 372                                 }
 373                         }
 374                         waitpid(current_child, &status, 0);
 375                 }
 376
 377                 do_restart = 0;
 378
 379                 /* Did the main process exit with an actual exit code? */
 380                 if (WIFEXITED(status)) {
 381
 382                         /* Exit code 0 means the watcher should exit */
 383                         if (WEXITSTATUS(status) == 0) {
 384                                 do_restart = 0;
 385                         }
 386
 387                         /* Exit code 101-109 means the watcher should exit */
 388                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 389                                 do_restart = 0;
 390                         }
 391
 392                         /* Any other exit code means we should restart. */
 393                         else {
 394                                 do_restart = 1;
 395                         }
 396                 }
 397
 398                 /* Any other type of termination (signals, etc.) should also restart. */
 399                 else {
 400                         do_restart = 1;
 401                 }
 402
 403         } while (do_restart);
 404
 405         if (pid_file) {
 406                 unlink(pid_file);
 407         }
 408         ShutDownLibCitadel ();
 409         exit(WEXITSTATUS(status));
 410 }
 411
 412
 413 /*
 414  * Spawn an additional worker thread into the pool.
 415  */
 416 void spawn_another_worker_thread()
 417 {
 418         pthread_t SessThread;   /* Thread descriptor */
 419         pthread_attr_t attr;    /* Thread attributes */
 420         int ret;
 421
 422         ++num_threads_existing;
 423         ++num_threads_executing;
 424
 425         /* set attributes for the new thread */
 426         pthread_attr_init(&attr);
 427         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 428
 429         /*
 430          * Our per-thread stacks need to be bigger than the default size,
 431          * otherwise the MIME parser crashes on FreeBSD.
 432          */
 433         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 434                 syslog(LOG_WARNING, "pthread_attr_setstacksize: %s\n", strerror(ret));
 435                 pthread_attr_destroy(&attr);
 436         }
 437
 438         /* now create the thread */
 439         if (pthread_create(&SessThread, &attr, (void *(*)(void *)) worker_entry, NULL) != 0) {
 440                 syslog(LOG_WARNING, "Can't create thread: %s\n", strerror(errno));
 441         }
 442
 443         /* free up the attributes */
 444         pthread_attr_destroy(&attr);
 445 }
 446
 447
 448 void
 449 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 450 {
 451         char dirbuffer[PATH_MAX]="";
 452         /* calculate all our path on a central place */
 453     /* where to keep our config */
 454
 455 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 456         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 457                          (home&!relh)?webcitdir:basedir, \
 458              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 459              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 460                          relhome, \
 461              (relhome[0]!='\0')?"/":"",\
 462                          dirbuffer,\
 463                          (dirbuffer[0]!='\0')?"/":"");
 464         basedir=RUNDIR;
 465         COMPUTE_DIRECTORY(socket_dir);
 466         basedir=WWWDIR "/static";
 467         COMPUTE_DIRECTORY(static_dir);
 468         basedir=WWWDIR "/static/icons";
 469         COMPUTE_DIRECTORY(static_icon_dir);
 470         basedir=WWWDIR "/static.local";
 471         COMPUTE_DIRECTORY(static_local_dir);
 472         StripSlashes(static_dir, 1);
 473         StripSlashes(static_icon_dir, 1);
 474         StripSlashes(static_local_dir, 1);
 475
 476         snprintf(file_crpt_file_key,
 477                  sizeof file_crpt_file_key,
 478                  "%s/citadel.key",
 479                  ctdl_key_dir);
 480         snprintf(file_crpt_file_csr,
 481                  sizeof file_crpt_file_csr,
 482                  "%s/citadel.csr",
 483                  ctdl_key_dir);
 484         snprintf(file_crpt_file_cer,
 485                  sizeof file_crpt_file_cer,
 486                  "%s/citadel.cer",
 487                  ctdl_key_dir);
 488
 489         /* we should go somewhere we can leave our coredump, if enabled... */
 490         syslog(LOG_INFO, "Changing directory to %s\n", socket_dir);
 491         if (chdir(webcitdir) != 0) {
 492                 perror("chdir");
 493         }
 494 }
 495
 496 void drop_root(uid_t UID)
 497 {
 498         struct passwd pw, *pwp = NULL;
 499
 500         /*
 501          * Now that we've bound the sockets, change to the Citadel user id and its
 502          * corresponding group ids
 503          */
 504         if (UID != -1) {
 505
 506 #ifdef HAVE_GETPWUID_R
 507 #ifdef SOLARIS_GETPWUID
 508                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 509 #else /* SOLARIS_GETPWUID */
 510                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 511 #endif /* SOLARIS_GETPWUID */
 512 #else /* HAVE_GETPWUID_R */
 513                 pwp = NULL;
 514 #endif /* HAVE_GETPWUID_R */
 515
 516                 if (pwp == NULL)
 517                         syslog(LOG_CRIT, "WARNING: getpwuid(%d): %s\n"
 518                                 "Group IDs will be incorrect.\n", UID,
 519                                 strerror(errno));
 520                 else {
 521                         initgroups(pw.pw_name, pw.pw_gid);
 522                         if (setgid(pw.pw_gid))
 523                                 syslog(LOG_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 524                                         strerror(errno));
 525                 }
 526                 syslog(LOG_INFO, "Changing uid to %ld\n", (long)UID);
 527                 if (setuid(UID) != 0) {
 528                         syslog(LOG_CRIT, "setuid() failed: %s\n", strerror(errno));
 529                 }
 530 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 531                 prctl(PR_SET_DUMPABLE, 1);
 532 #endif
 533         }
 534 }
 535
 536
 537 /*
 538  * print the actual stack frame.
 539  */
 540 void wc_backtrace(long LogLevel)
 541 {
 542 #ifdef HAVE_BACKTRACE
 543         void *stack_frames[50];
 544         size_t size, i;
 545         char **strings;
 546
 547
 548         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 549         strings = backtrace_symbols(stack_frames, size);
 550         for (i = 0; i < size; i++) {
 551                 if (strings != NULL)
 552                         syslog(LogLevel, "%s\n", strings[i]);
 553                 else
 554                         syslog(LogLevel, "%p\n", stack_frames[i]);
 555         }
 556         free(strings);
 557 #endif
 558 }