src/charon/charon.c

   1 /*
   2  * Copyright (C) 2006-2010 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 #ifdef HAVE_PRCTL
  21 #include <sys/prctl.h>
  22 #endif
  23 #define _POSIX_PTHREAD_SEMANTICS /* for two param sigwait on OpenSolaris */
  24 #include <signal.h>
  25 #undef _POSIX_PTHREAD_SEMANTICS
  26 #include <pthread.h>
  27 #include <sys/stat.h>
  28 #include <sys/types.h>
  29 #include <unistd.h>
  30 #include <getopt.h>
  31 #include <pwd.h>
  32 #include <grp.h>
  33
  34 #include <daemon.h>
  35
  36 #include <library.h>
  37 #include <utils/backtrace.h>
  38 #include <threading/thread.h>
  39
  40 /**
  41  * PID file, in which charon stores its process id
  42  */
  43 #define PID_FILE IPSEC_PIDDIR "/charon.pid"
  44
  45 /**
  46  * hook in library for debugging messages
  47  */
  48 extern void (*dbg) (int level, char *fmt, ...);
  49
  50 /**
  51  * Logging hook for library logs, using stderr output
  52  */
  53 static void dbg_stderr(int level, char *fmt, ...)
  54 {
  55         va_list args;
  56
  57         if (level <= 1)
  58         {
  59                 va_start(args, fmt);
  60                 fprintf(stderr, "00[LIB] ");
  61                 vfprintf(stderr, fmt, args);
  62                 fprintf(stderr, "\n");
  63                 va_end(args);
  64         }
  65 }
  66
  67 /**
  68  * Run the daemon and handle unix signals
  69  */
  70 static void run()
  71 {
  72         sigset_t set;
  73
  74         /* handle SIGINT, SIGHUP ans SIGTERM in this handler */
  75         sigemptyset(&set);
  76         sigaddset(&set, SIGINT);
  77         sigaddset(&set, SIGHUP);
  78         sigaddset(&set, SIGTERM);
  79         sigprocmask(SIG_BLOCK, &set, NULL);
  80
  81         while (TRUE)
  82         {
  83                 int sig;
  84                 int error;
  85
  86                 error = sigwait(&set, &sig);
  87                 if (error)
  88                 {
  89                         DBG1(DBG_DMN, "error %d while waiting for a signal", error);
  90                         return;
  91                 }
  92                 switch (sig)
  93                 {
  94                         case SIGHUP:
  95                         {
  96                                 DBG1(DBG_DMN, "signal of type SIGHUP received. Ignored");
  97                                 break;
  98                         }
  99                         case SIGINT:
 100                         {
 101                                 DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
 102                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 103                                 return;
 104                         }
 105                         case SIGTERM:
 106                         {
 107                                 DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
 108                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 109                                 return;
 110                         }
 111                         default:
 112                         {
 113                                 DBG1(DBG_DMN, "unknown signal %d received. Ignored", sig);
 114                                 break;
 115                         }
 116                 }
 117         }
 118 }
 119
 120 /**
 121  * drop daemon capabilities
 122  */
 123 static bool drop_capabilities()
 124 {
 125 #ifdef HAVE_PRCTL
 126         prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);
 127 #endif
 128
 129         if (setgid(charon->gid) != 0)
 130         {
 131                 DBG1(DBG_DMN, "change to unprivileged group failed");
 132                 return FALSE;
 133         }
 134         if (setuid(charon->uid) != 0)
 135         {
 136                 DBG1(DBG_DMN, "change to unprivileged user failed");
 137                 return FALSE;
 138         }
 139         if (!charon->drop_capabilities(charon))
 140         {
 141                 DBG1(DBG_DMN, "unable to drop daemon capabilities");
 142                 return FALSE;
 143         }
 144         return TRUE;
 145 }
 146
 147 /**
 148  * lookup UID and GID
 149  */
 150 static bool lookup_uid_gid()
 151 {
 152 #ifdef IPSEC_USER
 153         {
 154                 char buf[1024];
 155                 struct passwd passwd, *pwp;
 156
 157                 if (getpwnam_r(IPSEC_USER, &passwd, buf, sizeof(buf), &pwp) != 0 ||
 158                         pwp == NULL)
 159                 {
 160                         DBG1(DBG_DMN, "resolving user '"IPSEC_USER"' failed");
 161                         return FALSE;
 162                 }
 163                 charon->uid = pwp->pw_uid;
 164         }
 165 #endif
 166 #ifdef IPSEC_GROUP
 167         {
 168                 char buf[1024];
 169                 struct group group, *grp;
 170
 171                 if (getgrnam_r(IPSEC_GROUP, &group, buf, sizeof(buf), &grp) != 0 ||
 172                         grp == NULL)
 173                 {
 174                         DBG1(DBG_DMN, "resolving group '"IPSEC_GROUP"' failed");
 175                         return FALSE;
 176                 }
 177                 charon->gid = grp->gr_gid;
 178         }
 179 #endif
 180         return TRUE;
 181 }
 182
 183 /**
 184  * Handle SIGSEGV/SIGILL signals raised by threads
 185  */
 186 static void segv_handler(int signal)
 187 {
 188         backtrace_t *backtrace;
 189
 190         DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
 191         backtrace = backtrace_create(2);
 192         backtrace->log(backtrace, stderr);
 193         backtrace->destroy(backtrace);
 194
 195         DBG1(DBG_DMN, "killing ourself, received critical signal");
 196         abort();
 197 }
 198
 199 /**
 200  * Check/create PID file, return TRUE if already running
 201  */
 202 static bool check_pidfile()
 203 {
 204         struct stat stb;
 205         FILE *file;
 206
 207         if (stat(PID_FILE, &stb) == 0)
 208         {
 209                 file = fopen(PID_FILE, "r");
 210                 if (file)
 211                 {
 212                         char buf[64];
 213                         pid_t pid = 0;
 214
 215                         memset(buf, 0, sizeof(buf));
 216                         if (fread(buf, 1, sizeof(buf), file))
 217                         {
 218                                 pid = atoi(buf);
 219                         }
 220                         fclose(file);
 221                         if (pid && kill(pid, 0) == 0)
 222                         {       /* such a process is running */
 223                                 return TRUE;
 224                         }
 225                 }
 226                 DBG1(DBG_DMN, "removing pidfile '"PID_FILE"', process not running");
 227                 unlink(PID_FILE);
 228         }
 229
 230         /* create new pidfile */
 231         file = fopen(PID_FILE, "w");
 232         if (file)
 233         {
 234                 fprintf(file, "%d\n", getpid());
 235                 ignore_result(fchown(fileno(file), charon->uid, charon->gid));
 236                 fclose(file);
 237         }
 238         return FALSE;
 239 }
 240
 241 /**
 242  * print command line usage and exit
 243  */
 244 static void usage(const char *msg)
 245 {
 246         if (msg != NULL && *msg != '\0')
 247         {
 248                 fprintf(stderr, "%s\n", msg);
 249         }
 250         fprintf(stderr, "Usage: charon\n"
 251                                         "         [--help]\n"
 252                                         "         [--version]\n"
 253                                         "         [--use-syslog]\n"
 254                                         "         [--debug-<type> <level>]\n"
 255                                         "           <type>:  log context type (dmn|mgr|ike|chd|job|cfg|knl|net|enc|lib)\n"
 256                                         "           <level>: log verbosity (-1 = silent, 0 = audit, 1 = control,\n"
 257                                         "                                    2 = controlmore, 3 = raw, 4 = private)\n"
 258                                         "\n"
 259                    );
 260         exit(msg == NULL? 0 : 1);
 261 }
 262
 263 /**
 264  * Main function, starts the daemon.
 265  */
 266 int main(int argc, char *argv[])
 267 {
 268         struct sigaction action;
 269         bool use_syslog = FALSE;
 270         level_t levels[DBG_MAX];
 271         int group;
 272
 273         /* logging for library during initialization, as we have no bus yet */
 274         dbg = dbg_stderr;
 275
 276         /* initialize library */
 277         if (!library_init(NULL))
 278         {
 279                 library_deinit();
 280                 exit(SS_RC_LIBSTRONGSWAN_INTEGRITY);
 281         }
 282
 283         if (lib->integrity &&
 284                 !lib->integrity->check_file(lib->integrity, "charon", argv[0]))
 285         {
 286                 dbg_stderr(1, "integrity check of charon failed");
 287                 library_deinit();
 288                 exit(SS_RC_DAEMON_INTEGRITY);
 289         }
 290
 291         if (!libcharon_init())
 292         {
 293                 dbg_stderr(1, "initialization failed - aborting charon");
 294                 libcharon_deinit();
 295                 library_deinit();
 296                 exit(SS_RC_INITIALIZATION_FAILED);
 297         }
 298
 299         /* use CTRL loglevel for default */
 300         for (group = 0; group < DBG_MAX; group++)
 301         {
 302                 levels[group] = LEVEL_CTRL;
 303         }
 304
 305         /* handle arguments */
 306         for (;;)
 307         {
 308                 struct option long_opts[] = {
 309                         { "help", no_argument, NULL, 'h' },
 310                         { "version", no_argument, NULL, 'v' },
 311                         { "use-syslog", no_argument, NULL, 'l' },
 312                         /* TODO: handle "debug-all" */
 313                         { "debug-dmn", required_argument, &group, DBG_DMN },
 314                         { "debug-mgr", required_argument, &group, DBG_MGR },
 315                         { "debug-ike", required_argument, &group, DBG_IKE },
 316                         { "debug-chd", required_argument, &group, DBG_CHD },
 317                         { "debug-job", required_argument, &group, DBG_JOB },
 318                         { "debug-cfg", required_argument, &group, DBG_CFG },
 319                         { "debug-knl", required_argument, &group, DBG_KNL },
 320                         { "debug-net", required_argument, &group, DBG_NET },
 321                         { "debug-enc", required_argument, &group, DBG_ENC },
 322                         { "debug-lib", required_argument, &group, DBG_LIB },
 323                         { 0,0,0,0 }
 324                 };
 325
 326                 int c = getopt_long(argc, argv, "", long_opts, NULL);
 327                 switch (c)
 328                 {
 329                         case EOF:
 330                                 break;
 331                         case 'h':
 332                                 usage(NULL);
 333                                 break;
 334                         case 'v':
 335                                 printf("Linux strongSwan %s\n", VERSION);
 336                                 exit(0);
 337                         case 'l':
 338                                 use_syslog = TRUE;
 339                                 continue;
 340                         case 0:
 341                                 /* option is in group */
 342                                 levels[group] = atoi(optarg);
 343                                 continue;
 344                         default:
 345                                 usage("");
 346                                 break;
 347                 }
 348                 break;
 349         }
 350
 351         if (!lookup_uid_gid())
 352         {
 353                 dbg_stderr(1, "invalid uid/gid - aborting charon");
 354                 libcharon_deinit();
 355                 library_deinit();
 356                 exit(SS_RC_INITIALIZATION_FAILED);
 357         }
 358
 359         /* initialize daemon */
 360         if (!charon->initialize(charon, use_syslog, levels))
 361         {
 362                 DBG1(DBG_DMN, "initialization failed - aborting charon");
 363                 libcharon_deinit();
 364                 library_deinit();
 365                 exit(SS_RC_INITIALIZATION_FAILED);
 366         }
 367
 368         if (check_pidfile())
 369         {
 370                 DBG1(DBG_DMN, "charon already running (\""PID_FILE"\" exists)");
 371                 libcharon_deinit();
 372                 library_deinit();
 373                 exit(-1);
 374         }
 375
 376         if (!drop_capabilities())
 377         {
 378                 DBG1(DBG_DMN, "capability dropping failed - aborting charon");
 379                 libcharon_deinit();
 380                 library_deinit();
 381                 exit(SS_RC_INITIALIZATION_FAILED);
 382         }
 383
 384         /* add handler for SEGV and ILL,
 385          * INT, TERM and HUP are handled by sigwait() in run() */
 386         action.sa_handler = segv_handler;
 387         action.sa_flags = 0;
 388         sigemptyset(&action.sa_mask);
 389         sigaddset(&action.sa_mask, SIGINT);
 390         sigaddset(&action.sa_mask, SIGTERM);
 391         sigaddset(&action.sa_mask, SIGHUP);
 392         sigaction(SIGSEGV, &action, NULL);
 393         sigaction(SIGILL, &action, NULL);
 394         sigaction(SIGBUS, &action, NULL);
 395         action.sa_handler = SIG_IGN;
 396         sigaction(SIGPIPE, &action, NULL);
 397
 398         pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
 399
 400         /* start daemon (i.e. the threads in the thread-pool) */
 401         charon->start(charon);
 402
 403         /* main thread goes to run loop */
 404         run();
 405
 406         /* normal termination, cleanup and exit */
 407         libcharon_deinit();
 408         library_deinit();
 409
 410         unlink(PID_FILE);
 411
 412         return 0;
 413 }
 414