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 #ifndef HAVE_SNPRINTF
  63 #include "snprintf.h"
  64 #endif
  65 #include "webserver.h"
  66 #include "modules_init.h"
  67 #if HAVE_BACKTRACE
  68 #include <execinfo.h>
  69 #endif
  70
  71 pthread_mutex_t Critters[MAX_SEMAPHORES];       /* Things needing locking */
  72 pthread_key_t MyConKey;                         /* TSD key for MyContext() */
  73 pthread_key_t MyReq;                            /* TSD key for MyReq() */
  74 int msock;                      /* master listening socket */
  75 int time_to_die = 0;            /* Nonzero if server is shutting down */
  76
  77 extern void *context_loop(ParsedHttpHdrs *Hdr);
  78 extern void *housekeeping_loop(void);
  79 extern void do_housekeeping(void);
  80
  81 char ctdl_key_dir[PATH_MAX]=SSL_DIR;
  82 char file_crpt_file_key[PATH_MAX]="";
  83 char file_crpt_file_csr[PATH_MAX]="";
  84 char file_crpt_file_cer[PATH_MAX]="";
  85
  86 const char editor_absolut_dir[PATH_MAX]=EDITORDIR;      /* nailed to what configure gives us. */
  87 char static_dir[PATH_MAX];              /* calculated on startup */
  88 char static_local_dir[PATH_MAX];                /* calculated on startup */
  89 char static_icon_dir[PATH_MAX];          /* where should we find our mime icons? */
  90 char  *static_dirs[]={                          /* needs same sort order as the web mapping */
  91         (char*)static_dir,                      /* our templates on disk */
  92         (char*)static_local_dir,                /* user provided templates disk */
  93         (char*)editor_absolut_dir,              /* the editor on disk */
  94         (char*)static_icon_dir                  /* our icons... */
  95 };
  96
  97 int ExitPipe[2];
  98
  99 void InitialiseSemaphores(void)
 100 {
 101         int i;
 102
 103         /* Set up a bunch of semaphores to be used for critical sections */
 104         for (i=0; i<MAX_SEMAPHORES; ++i) {
 105                 pthread_mutex_init(&Critters[i], NULL);
 106         }
 107
 108         if (pipe(ExitPipe))
 109         {
 110                 syslog(2, "Failed to open exit pipe: %d [%s]\n",
 111                        errno,
 112                        strerror(errno));
 113
 114                 exit(-1);
 115         }
 116 }
 117
 118 /*
 119  * Obtain a semaphore lock to begin a critical section.
 120  */
 121 void begin_critical_section(int which_one)
 122 {
 123         pthread_mutex_lock(&Critters[which_one]);
 124 }
 125
 126 /*
 127  * Release a semaphore lock to end a critical section.
 128  */
 129 void end_critical_section(int which_one)
 130 {
 131         pthread_mutex_unlock(&Critters[which_one]);
 132 }
 133
 134
 135 void ShutDownWebcit(void)
 136 {
 137         free_zone_directory ();
 138         icaltimezone_release_zone_tab ();
 139         icalmemory_free_ring ();
 140         ShutDownLibCitadel ();
 141         shutdown_modules ();
 142 #ifdef HAVE_OPENSSL
 143         if (is_https) {
 144                 shutdown_ssl();
 145         }
 146 #endif
 147 }
 148
 149 /*
 150  * Entry point for worker threads
 151  */
 152 void worker_entry(void)
 153 {
 154         int ssock;
 155         int i = 0;
 156         int fail_this_transaction = 0;
 157         ParsedHttpHdrs Hdr;
 158
 159         memset(&Hdr, 0, sizeof(ParsedHttpHdrs));
 160         Hdr.HR.eReqType = eGET;
 161         http_new_modules(&Hdr);
 162
 163         do {
 164                 /* Each worker thread blocks on accept() while waiting for something to do. */
 165                 fail_this_transaction = 0;
 166                 ssock = -1;
 167                 errno = EAGAIN;
 168                 do {
 169                         fd_set wset;
 170                         --num_threads_executing;
 171                         FD_ZERO(&wset);
 172                         FD_SET(msock, &wset);
 173                         FD_SET(ExitPipe[1], &wset);
 174
 175                         select(msock + 1, NULL, &wset, NULL, NULL);
 176                         if (time_to_die)
 177                                 break;
 178
 179                         ssock = accept(msock, NULL, 0);
 180                         ++num_threads_executing;
 181                         if (ssock < 0) fail_this_transaction = 1;
 182                 } while ((msock > 0) && (ssock < 0)  && (time_to_die == 0));
 183
 184                 if ((msock == -1)||(time_to_die))
 185                 {/* ok, we're going down. */
 186                         int shutdown = 0;
 187
 188                         /* The first thread to get here will have to do the cleanup.
 189                          * Make sure it's really just one.
 190                          */
 191                         begin_critical_section(S_SHUTDOWN);
 192                         if (msock == -1)
 193                         {
 194                                 msock = -2;
 195                                 shutdown = 1;
 196                         }
 197                         end_critical_section(S_SHUTDOWN);
 198                         if (shutdown == 1)
 199                         {/* we're the one to cleanup the mess. */
 200                                 http_destroy_modules(&Hdr);
 201                                 syslog(2, "I'm master shutdown: tagging sessions to be killed.\n");
 202                                 shutdown_sessions();
 203                                 syslog(2, "master shutdown: waiting for others\n");
 204                                 sleeeeeeeeeep(1); /* wait so some others might finish... */
 205                                 syslog(2, "master shutdown: cleaning up sessions\n");
 206                                 do_housekeeping();
 207                                 syslog(2, "master shutdown: cleaning up libical\n");
 208
 209                                 ShutDownWebcit();
 210
 211                                 syslog(2, "master shutdown exiting.\n");
 212                                 exit(0);
 213                         }
 214                         break;
 215                 }
 216                 if (ssock < 0 ) continue;
 217
 218                 check_thread_pool_size();
 219
 220                 /* Now do something. */
 221                 if (msock < 0) {
 222                         if (ssock > 0) close (ssock);
 223                         syslog(2, "in between.");
 224                         pthread_exit(NULL);
 225                 } else {
 226                         /* Got it? do some real work! */
 227                         /* Set the SO_REUSEADDR socket option */
 228                         i = 1;
 229                         setsockopt(ssock, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 230
 231                         /* If we are an HTTPS server, go crypto now. */
 232 #ifdef HAVE_OPENSSL
 233                         if (is_https) {
 234                                 if (starttls(ssock) != 0) {
 235                                         fail_this_transaction = 1;
 236                                         close(ssock);
 237                                 }
 238                         }
 239                         else
 240 #endif
 241                         {
 242                                 int fdflags;
 243                                 fdflags = fcntl(ssock, F_GETFL);
 244                                 if (fdflags < 0)
 245                                         syslog(1, "unable to get server socket flags! %s \n",
 246                                                 strerror(errno));
 247                                 fdflags = fdflags | O_NONBLOCK;
 248                                 if (fcntl(ssock, F_SETFL, fdflags) < 0)
 249                                         syslog(1, "unable to set server socket nonblocking flags! %s \n",
 250                                                 strerror(errno));
 251                         }
 252
 253                         if (fail_this_transaction == 0) {
 254                                 Hdr.http_sock = ssock;
 255
 256                                 /* Perform an HTTP transaction... */
 257                                 context_loop(&Hdr);
 258
 259                                 /* Shut down SSL/TLS if required... */
 260 #ifdef HAVE_OPENSSL
 261                                 if (is_https) {
 262                                         endtls();
 263                                 }
 264 #endif
 265
 266                                 /* ...and close the socket. */
 267                                 if (Hdr.http_sock > 0) {
 268                                         lingering_close(ssock);
 269                                 }
 270                                 http_detach_modules(&Hdr);
 271
 272                         }
 273
 274                 }
 275
 276         } while (!time_to_die);
 277
 278         http_destroy_modules(&Hdr);
 279         syslog(1, "Thread exiting.\n");
 280         pthread_exit(NULL);
 281 }
 282
 283
 284 /*
 285  * Shut us down the regular way.
 286  * signum is the signal we want to forward
 287  */
 288 pid_t current_child;
 289 void graceful_shutdown_watcher(int signum) {
 290         syslog(1, "Watcher thread exiting.\n");
 291         write(ExitPipe[0], HKEY("                              "));
 292         kill(current_child, signum);
 293         if (signum != SIGHUP)
 294                 exit(0);
 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         syslog(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         write(ExitPipe[0], HKEY("                              "));
 316 }
 317
 318
 319 /*
 320  * Start running as a daemon.
 321  */
 322 void start_daemon(char *pid_file)
 323 {
 324         int status = 0;
 325         pid_t child = 0;
 326         FILE *fp;
 327         int do_restart = 0;
 328
 329         current_child = 0;
 330
 331         /* Close stdin/stdout/stderr and replace them with /dev/null.
 332          * We don't just call close() because we don't want these fd's
 333          * to be reused for other files.
 334          */
 335         chdir("/");
 336
 337         signal(SIGHUP, SIG_IGN);
 338         signal(SIGINT, SIG_IGN);
 339         signal(SIGQUIT, SIG_IGN);
 340
 341         child = fork();
 342         if (child != 0) {
 343                 exit(0);
 344         }
 345
 346         setsid();
 347         umask(0);
 348         freopen("/dev/null", "r", stdin);
 349         freopen("/dev/null", "w", stdout);
 350         freopen("/dev/null", "w", stderr);
 351         signal(SIGTERM, graceful_shutdown_watcher);
 352         signal(SIGHUP, graceful_shutdown_watcher);
 353
 354         do {
 355                 current_child = fork();
 356
 357
 358                 if (current_child < 0) {
 359                         perror("fork");
 360                         ShutDownLibCitadel ();
 361                         exit(errno);
 362                 }
 363
 364                 else if (current_child == 0) {  /* child process */
 365                         signal(SIGHUP, graceful_shutdown);
 366
 367                         return; /* continue starting webcit. */
 368                 }
 369                 else { /* watcher process */
 370                         if (pid_file) {
 371                                 fp = fopen(pid_file, "w");
 372                                 if (fp != NULL) {
 373                                         fprintf(fp, "%d\n", getpid());
 374                                         fclose(fp);
 375                                 }
 376                         }
 377                         waitpid(current_child, &status, 0);
 378                 }
 379
 380                 do_restart = 0;
 381
 382                 /* Did the main process exit with an actual exit code? */
 383                 if (WIFEXITED(status)) {
 384
 385                         /* Exit code 0 means the watcher should exit */
 386                         if (WEXITSTATUS(status) == 0) {
 387                                 do_restart = 0;
 388                         }
 389
 390                         /* Exit code 101-109 means the watcher should exit */
 391                         else if ( (WEXITSTATUS(status) >= 101) && (WEXITSTATUS(status) <= 109) ) {
 392                                 do_restart = 0;
 393                         }
 394
 395                         /* Any other exit code means we should restart. */
 396                         else {
 397                                 do_restart = 1;
 398                         }
 399                 }
 400
 401                 /* Any other type of termination (signals, etc.) should also restart. */
 402                 else {
 403                         do_restart = 1;
 404                 }
 405
 406         } while (do_restart);
 407
 408         if (pid_file) {
 409                 unlink(pid_file);
 410         }
 411         ShutDownLibCitadel ();
 412         exit(WEXITSTATUS(status));
 413 }
 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         ++num_threads_existing;
 426         ++num_threads_executing;
 427
 428         /* set attributes for the new thread */
 429         pthread_attr_init(&attr);
 430         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 431
 432         /*
 433          * Our per-thread stacks need to be bigger than the default size,
 434          * otherwise the MIME parser crashes on FreeBSD.
 435          */
 436         if ((ret = pthread_attr_setstacksize(&attr, 1024 * 1024))) {
 437                 syslog(1, "pthread_attr_setstacksize: %s\n", strerror(ret));
 438                 pthread_attr_destroy(&attr);
 439         }
 440
 441         /* now create the thread */
 442         if (pthread_create(&SessThread, &attr, (void *(*)(void *)) worker_entry, NULL) != 0) {
 443                 syslog(1, "Can't create thread: %s\n", strerror(errno));
 444         }
 445
 446         /* free up the attributes */
 447         pthread_attr_destroy(&attr);
 448 }
 449
 450
 451 void
 452 webcit_calc_dirs_n_files(int relh, const char *basedir, int home, char *webcitdir, char *relhome)
 453 {
 454         char dirbuffer[PATH_MAX]="";
 455         /* calculate all our path on a central place */
 456     /* where to keep our config */
 457
 458 #define COMPUTE_DIRECTORY(SUBDIR) memcpy(dirbuffer,SUBDIR, sizeof dirbuffer);\
 459         snprintf(SUBDIR,sizeof SUBDIR,  "%s%s%s%s%s%s%s", \
 460                          (home&!relh)?webcitdir:basedir, \
 461              ((basedir!=webcitdir)&(home&!relh))?basedir:"/", \
 462              ((basedir!=webcitdir)&(home&!relh))?"/":"", \
 463                          relhome, \
 464              (relhome[0]!='\0')?"/":"",\
 465                          dirbuffer,\
 466                          (dirbuffer[0]!='\0')?"/":"");
 467         basedir=RUNDIR;
 468         COMPUTE_DIRECTORY(socket_dir);
 469         basedir=WWWDIR "/static";
 470         COMPUTE_DIRECTORY(static_dir);
 471         basedir=WWWDIR "/static/icons";
 472         COMPUTE_DIRECTORY(static_icon_dir);
 473         basedir=WWWDIR "/static.local";
 474         COMPUTE_DIRECTORY(static_local_dir);
 475         StripSlashes(static_dir, 1);
 476         StripSlashes(static_icon_dir, 1);
 477         StripSlashes(static_local_dir, 1);
 478
 479         snprintf(file_crpt_file_key,
 480                  sizeof file_crpt_file_key,
 481                  "%s/citadel.key",
 482                  ctdl_key_dir);
 483         snprintf(file_crpt_file_csr,
 484                  sizeof file_crpt_file_csr,
 485                  "%s/citadel.csr",
 486                  ctdl_key_dir);
 487         snprintf(file_crpt_file_cer,
 488                  sizeof file_crpt_file_cer,
 489                  "%s/citadel.cer",
 490                  ctdl_key_dir);
 491
 492         /* we should go somewhere we can leave our coredump, if enabled... */
 493         syslog(9, "Changing directory to %s\n", socket_dir);
 494         if (chdir(webcitdir) != 0) {
 495                 perror("chdir");
 496         }
 497 }
 498
 499 void drop_root(uid_t UID)
 500 {
 501         struct passwd pw, *pwp = NULL;
 502
 503         /*
 504          * Now that we've bound the sockets, change to the Citadel user id and its
 505          * corresponding group ids
 506          */
 507         if (UID != -1) {
 508
 509 #ifdef HAVE_GETPWUID_R
 510 #ifdef SOLARIS_GETPWUID
 511                 pwp = getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf));
 512 #else /* SOLARIS_GETPWUID */
 513                 getpwuid_r(UID, &pw, pwbuf, sizeof(pwbuf), &pwp);
 514 #endif /* SOLARIS_GETPWUID */
 515 #else /* HAVE_GETPWUID_R */
 516                 pwp = NULL;
 517 #endif /* HAVE_GETPWUID_R */
 518
 519                 if (pwp == NULL)
 520                         syslog(LOG_CRIT, "WARNING: getpwuid(%d): %s\n"
 521                                 "Group IDs will be incorrect.\n", UID,
 522                                 strerror(errno));
 523                 else {
 524                         initgroups(pw.pw_name, pw.pw_gid);
 525                         if (setgid(pw.pw_gid))
 526                                 syslog(LOG_CRIT, "setgid(%ld): %s\n", (long)pw.pw_gid,
 527                                         strerror(errno));
 528                 }
 529                 syslog(LOG_INFO, "Changing uid to %ld\n", (long)UID);
 530                 if (setuid(UID) != 0) {
 531                         syslog(LOG_CRIT, "setuid() failed: %s\n", strerror(errno));
 532                 }
 533 #if defined (HAVE_SYS_PRCTL_H) && defined (PR_SET_DUMPABLE)
 534                 prctl(PR_SET_DUMPABLE, 1);
 535 #endif
 536         }
 537 }
 538
 539
 540 /*
 541  * print the actual stack frame.
 542  */
 543 void wc_backtrace(void)
 544 {
 545 #ifdef HAVE_BACKTRACE
 546         void *stack_frames[50];
 547         size_t size, i;
 548         char **strings;
 549
 550
 551         size = backtrace(stack_frames, sizeof(stack_frames) / sizeof(void*));
 552         strings = backtrace_symbols(stack_frames, size);
 553         for (i = 0; i < size; i++) {
 554                 if (strings != NULL)
 555                         syslog(1, "%s\n", strings[i]);
 556                 else
 557                         syslog(1, "%p\n", stack_frames[i]);
 558         }
 559         free(strings);
 560 #endif
 561 }