src/charon/charon.c

   1 /*
   2  * Copyright (C) 2006-2012 Tobias Brunner
   3  * Copyright (C) 2005-2009 Martin Willi
   4  * Copyright (C) 2006 Daniel Roethlisberger
   5  * Copyright (C) 2005 Jan Hutter
   6  * Hochschule fuer Technik Rapperswil
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2 of the License, or (at your
  11  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  * for more details.
  17  */
  18
  19 #include <stdio.h>
  20 #include <signal.h>
  21 #include <pthread.h>
  22 #include <sys/stat.h>
  23 #include <sys/types.h>
  24 #include <sys/utsname.h>
  25 #include <unistd.h>
  26 #include <getopt.h>
  27 #include <fcntl.h>
  28 #include <errno.h>
  29
  30 #include <hydra.h>
  31 #include <daemon.h>
  32
  33 #include <library.h>
  34 #include <utils/backtrace.h>
  35 #include <threading/thread.h>
  36
  37 #ifdef ANDROID
  38 #include <private/android_filesystem_config.h> /* for AID_VPN */
  39 #endif
  40
  41 /**
  42  * PID file, in which charon stores its process id
  43  */
  44 #define PID_FILE IPSEC_PIDDIR "/charon.pid"
  45
  46 /**
  47  * Default user and group
  48  */
  49 #ifndef IPSEC_USER
  50 #define IPSEC_USER NULL
  51 #endif
  52
  53 #ifndef IPSEC_GROUP
  54 #define IPSEC_GROUP NULL
  55 #endif
  56
  57 /**
  58  * Global reference to PID file (required to truncate, if undeletable)
  59  */
  60 static FILE *pidfile = NULL;
  61
  62 /**
  63  * Log levels as defined via command line arguments
  64  */
  65 static level_t levels[DBG_MAX];
  66
  67 /**
  68  * Whether to only use syslog when logging
  69  */
  70 static bool use_syslog = FALSE;
  71
  72 /**
  73  * hook in library for debugging messages
  74  */
  75 extern void (*dbg) (debug_t group, level_t level, char *fmt, ...);
  76
  77 /**
  78  * Logging hook for library logs, using stderr output
  79  */
  80 static void dbg_stderr(debug_t group, level_t level, char *fmt, ...)
  81 {
  82         va_list args;
  83
  84         if (level <= 1)
  85         {
  86                 va_start(args, fmt);
  87                 fprintf(stderr, "00[%N] ", debug_names, group);
  88                 vfprintf(stderr, fmt, args);
  89                 fprintf(stderr, "\n");
  90                 va_end(args);
  91         }
  92 }
  93
  94 /**
  95  * Run the daemon and handle unix signals
  96  */
  97 static void run()
  98 {
  99         sigset_t set;
 100
 101         /* handle SIGINT, SIGHUP ans SIGTERM in this handler */
 102         sigemptyset(&set);
 103         sigaddset(&set, SIGINT);
 104         sigaddset(&set, SIGHUP);
 105         sigaddset(&set, SIGTERM);
 106         sigprocmask(SIG_BLOCK, &set, NULL);
 107
 108         while (TRUE)
 109         {
 110                 int sig;
 111
 112                 sig = sigwaitinfo(&set, NULL);
 113                 if (sig == -1)
 114                 {
 115                         DBG1(DBG_DMN, "waiting for signal failed: %s", strerror(errno));
 116                         return;
 117                 }
 118                 switch (sig)
 119                 {
 120                         case SIGHUP:
 121                         {
 122                                 DBG1(DBG_DMN, "signal of type SIGHUP received. Reloading "
 123                                          "configuration");
 124                                 if (lib->settings->load_files(lib->settings, lib->conf, FALSE))
 125                                 {
 126                                         charon->load_loggers(charon, levels, !use_syslog);
 127                                         lib->plugins->reload(lib->plugins, NULL);
 128                                 }
 129                                 else
 130                                 {
 131                                         DBG1(DBG_DMN, "reloading config failed, keeping old");
 132                                 }
 133                                 break;
 134                         }
 135                         case SIGINT:
 136                         {
 137                                 DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
 138                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 139                                 return;
 140                         }
 141                         case SIGTERM:
 142                         {
 143                                 DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
 144                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 145                                 return;
 146                         }
 147                         default:
 148                         {
 149                                 DBG1(DBG_DMN, "unknown signal %d received. Ignored", sig);
 150                                 break;
 151                         }
 152                 }
 153         }
 154 }
 155
 156 /**
 157  * lookup UID and GID
 158  */
 159 static bool lookup_uid_gid()
 160 {
 161         char *name;
 162
 163         name = lib->settings->get_str(lib->settings, "charon.user", IPSEC_USER);
 164         if (name && !lib->caps->resolve_uid(lib->caps, name))
 165         {
 166                 return FALSE;
 167         }
 168         name = lib->settings->get_str(lib->settings, "charon.group", IPSEC_GROUP);
 169         if (name && !lib->caps->resolve_gid(lib->caps, name))
 170         {
 171                 return FALSE;
 172         }
 173 #ifdef ANDROID
 174         lib->caps->set_uid(lib->caps, AID_VPN);
 175 #endif
 176         return TRUE;
 177 }
 178
 179 /**
 180  * Handle SIGSEGV/SIGILL signals raised by threads
 181  */
 182 static void segv_handler(int signal)
 183 {
 184         backtrace_t *backtrace;
 185
 186         DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
 187         backtrace = backtrace_create(2);
 188         backtrace->log(backtrace, NULL, TRUE);
 189         backtrace->log(backtrace, stderr, TRUE);
 190         backtrace->destroy(backtrace);
 191
 192         DBG1(DBG_DMN, "killing ourself, received critical signal");
 193         abort();
 194 }
 195
 196 /**
 197  * Check/create PID file, return TRUE if already running
 198  */
 199 static bool check_pidfile()
 200 {
 201         struct stat stb;
 202
 203         if (stat(PID_FILE, &stb) == 0)
 204         {
 205                 pidfile = fopen(PID_FILE, "r");
 206                 if (pidfile)
 207                 {
 208                         char buf[64];
 209                         pid_t pid = 0;
 210
 211                         memset(buf, 0, sizeof(buf));
 212                         if (fread(buf, 1, sizeof(buf), pidfile))
 213                         {
 214                                 buf[sizeof(buf) - 1] = '\0';
 215                                 pid = atoi(buf);
 216                         }
 217                         fclose(pidfile);
 218                         if (pid && kill(pid, 0) == 0)
 219                         {       /* such a process is running */
 220                                 return TRUE;
 221                         }
 222                 }
 223                 DBG1(DBG_DMN, "removing pidfile '"PID_FILE"', process not running");
 224                 unlink(PID_FILE);
 225         }
 226
 227         /* create new pidfile */
 228         pidfile = fopen(PID_FILE, "w");
 229         if (pidfile)
 230         {
 231                 int fd;
 232
 233                 fd = fileno(pidfile);
 234                 if (fd == -1 || fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
 235                 {
 236                         DBG1(DBG_LIB, "setting FD_CLOEXEC for '"PID_FILE"' failed: %s",
 237                                  strerror(errno));
 238                 }
 239                 ignore_result(fchown(fileno(pidfile),
 240                                                          lib->caps->get_uid(lib->caps),
 241                                                          lib->caps->get_gid(lib->caps)));
 242                 fprintf(pidfile, "%d\n", getpid());
 243                 fflush(pidfile);
 244         }
 245         return FALSE;
 246 }
 247
 248 /**
 249  * Delete/truncate the PID file
 250  */
 251 static void unlink_pidfile()
 252 {
 253         /* because unlinking the PID file may fail, we truncate it to ensure the
 254          * daemon can be properly restarted.  one probable cause for this is the
 255          * combination of not running as root and the effective user lacking
 256          * permissions on the parent dir(s) of the PID file */
 257         if (pidfile)
 258         {
 259                 ignore_result(ftruncate(fileno(pidfile), 0));
 260                 fclose(pidfile);
 261         }
 262         unlink(PID_FILE);
 263 }
 264
 265 /**
 266  * print command line usage and exit
 267  */
 268 static void usage(const char *msg)
 269 {
 270         if (msg != NULL && *msg != '\0')
 271         {
 272                 fprintf(stderr, "%s\n", msg);
 273         }
 274         fprintf(stderr, "Usage: charon\n"
 275                                         "         [--help]\n"
 276                                         "         [--version]\n"
 277                                         "         [--use-syslog]\n"
 278                                         "         [--debug-<type> <level>]\n"
 279                                         "           <type>:  log context type (dmn|mgr|ike|chd|job|cfg|knl|net|asn|enc|tnc|imc|imv|pts|tls|esp|lib)\n"
 280                                         "           <level>: log verbosity (-1 = silent, 0 = audit, 1 = control,\n"
 281                                         "                                    2 = controlmore, 3 = raw, 4 = private)\n"
 282                                         "\n"
 283                    );
 284 }
 285
 286 /**
 287  * Main function, starts the daemon.
 288  */
 289 int main(int argc, char *argv[])
 290 {
 291         struct sigaction action;
 292         int group, status = SS_RC_INITIALIZATION_FAILED;
 293         struct utsname utsname;
 294
 295         /* logging for library during initialization, as we have no bus yet */
 296         dbg = dbg_stderr;
 297
 298         /* initialize library */
 299         if (!library_init(NULL, "charon"))
 300         {
 301                 library_deinit();
 302                 exit(SS_RC_LIBSTRONGSWAN_INTEGRITY);
 303         }
 304
 305         if (lib->integrity &&
 306                 !lib->integrity->check_file(lib->integrity, "charon", argv[0]))
 307         {
 308                 dbg_stderr(DBG_DMN, 1, "integrity check of charon failed");
 309                 library_deinit();
 310                 exit(SS_RC_DAEMON_INTEGRITY);
 311         }
 312
 313         if (!libhydra_init())
 314         {
 315                 dbg_stderr(DBG_DMN, 1, "initialization failed - aborting charon");
 316                 libhydra_deinit();
 317                 library_deinit();
 318                 exit(SS_RC_INITIALIZATION_FAILED);
 319         }
 320
 321         if (!libcharon_init())
 322         {
 323                 dbg_stderr(DBG_DMN, 1, "initialization failed - aborting charon");
 324                 goto deinit;
 325         }
 326
 327         /* use CTRL loglevel for default */
 328         for (group = 0; group < DBG_MAX; group++)
 329         {
 330                 levels[group] = LEVEL_CTRL;
 331         }
 332
 333         /* handle arguments */
 334         for (;;)
 335         {
 336                 struct option long_opts[] = {
 337                         { "help", no_argument, NULL, 'h' },
 338                         { "version", no_argument, NULL, 'v' },
 339                         { "use-syslog", no_argument, NULL, 'l' },
 340                         /* TODO: handle "debug-all" */
 341                         { "debug-dmn", required_argument, &group, DBG_DMN },
 342                         { "debug-mgr", required_argument, &group, DBG_MGR },
 343                         { "debug-ike", required_argument, &group, DBG_IKE },
 344                         { "debug-chd", required_argument, &group, DBG_CHD },
 345                         { "debug-job", required_argument, &group, DBG_JOB },
 346                         { "debug-cfg", required_argument, &group, DBG_CFG },
 347                         { "debug-knl", required_argument, &group, DBG_KNL },
 348                         { "debug-net", required_argument, &group, DBG_NET },
 349                         { "debug-asn", required_argument, &group, DBG_ASN },
 350                         { "debug-enc", required_argument, &group, DBG_ENC },
 351                         { "debug-tnc", required_argument, &group, DBG_TNC },
 352                         { "debug-imc", required_argument, &group, DBG_IMC },
 353                         { "debug-imv", required_argument, &group, DBG_IMV },
 354                         { "debug-pts", required_argument, &group, DBG_PTS },
 355                         { "debug-tls", required_argument, &group, DBG_TLS },
 356                         { "debug-esp", required_argument, &group, DBG_ESP },
 357                         { "debug-lib", required_argument, &group, DBG_LIB },
 358                         { 0,0,0,0 }
 359                 };
 360
 361                 int c = getopt_long(argc, argv, "", long_opts, NULL);
 362                 switch (c)
 363                 {
 364                         case EOF:
 365                                 break;
 366                         case 'h':
 367                                 usage(NULL);
 368                                 status = 0;
 369                                 goto deinit;
 370                         case 'v':
 371                                 printf("Linux strongSwan %s\n", VERSION);
 372                                 status = 0;
 373                                 goto deinit;
 374                         case 'l':
 375                                 use_syslog = TRUE;
 376                                 continue;
 377                         case 0:
 378                                 /* option is in group */
 379                                 levels[group] = atoi(optarg);
 380                                 continue;
 381                         default:
 382                                 usage("");
 383                                 status = 1;
 384                                 goto deinit;
 385                 }
 386                 break;
 387         }
 388
 389         if (!lookup_uid_gid())
 390         {
 391                 dbg_stderr(DBG_DMN, 1, "invalid uid/gid - aborting charon");
 392                 goto deinit;
 393         }
 394
 395         charon->load_loggers(charon, levels, !use_syslog);
 396
 397         if (uname(&utsname) != 0)
 398         {
 399                 memset(&utsname, 0, sizeof(utsname));
 400         }
 401         DBG1(DBG_DMN, "Starting IKE charon daemon (strongSwan "VERSION", %s %s, %s)",
 402                   utsname.sysname, utsname.release, utsname.machine);
 403         if (lib->integrity)
 404         {
 405                 DBG1(DBG_DMN, "integrity tests enabled:");
 406                 DBG1(DBG_DMN, "lib    'libstrongswan': passed file and segment integrity tests");
 407                 DBG1(DBG_DMN, "lib    'libhydra': passed file and segment integrity tests");
 408                 DBG1(DBG_DMN, "lib    'libcharon': passed file and segment integrity tests");
 409                 DBG1(DBG_DMN, "daemon 'charon': passed file integrity test");
 410         }
 411
 412         /* initialize daemon */
 413         if (!charon->initialize(charon,
 414                                 lib->settings->get_str(lib->settings, "charon.load", PLUGINS)))
 415         {
 416                 DBG1(DBG_DMN, "initialization failed - aborting charon");
 417                 goto deinit;
 418         }
 419         lib->plugins->status(lib->plugins, LEVEL_CTRL);
 420
 421         if (check_pidfile())
 422         {
 423                 DBG1(DBG_DMN, "charon already running (\""PID_FILE"\" exists)");
 424                 goto deinit;
 425         }
 426
 427         if (!lib->caps->drop(lib->caps))
 428         {
 429                 DBG1(DBG_DMN, "capability dropping failed - aborting charon");
 430                 goto deinit;
 431         }
 432
 433         /* add handler for SEGV and ILL,
 434          * INT, TERM and HUP are handled by sigwaitinfo() in run() */
 435         action.sa_handler = segv_handler;
 436         action.sa_flags = 0;
 437         sigemptyset(&action.sa_mask);
 438         sigaddset(&action.sa_mask, SIGINT);
 439         sigaddset(&action.sa_mask, SIGTERM);
 440         sigaddset(&action.sa_mask, SIGHUP);
 441         sigaction(SIGSEGV, &action, NULL);
 442         sigaction(SIGILL, &action, NULL);
 443         sigaction(SIGBUS, &action, NULL);
 444         action.sa_handler = SIG_IGN;
 445         sigaction(SIGPIPE, &action, NULL);
 446
 447         pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
 448
 449         /* start daemon (i.e. the threads in the thread-pool) */
 450         charon->start(charon);
 451
 452         /* main thread goes to run loop */
 453         run();
 454
 455         /* normal termination, cleanup and exit */
 456         unlink_pidfile();
 457         status = 0;
 458
 459 deinit:
 460         libcharon_deinit();
 461         libhydra_deinit();
 462         library_deinit();
 463         return status;
 464 }