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 <hydra.h>
  35 #include <daemon.h>
  36
  37 #include <library.h>
  38 #include <utils/backtrace.h>
  39 #include <threading/thread.h>
  40
  41 /**
  42  * PID file, in which charon stores its process id
  43  */
  44 #define PID_FILE IPSEC_PIDDIR "/charon.pid"
  45
  46 /**
  47  * hook in library for debugging messages
  48  */
  49 extern void (*dbg) (int level, char *fmt, ...);
  50
  51 /**
  52  * Logging hook for library logs, using stderr output
  53  */
  54 static void dbg_stderr(int level, char *fmt, ...)
  55 {
  56         va_list args;
  57
  58         if (level <= 1)
  59         {
  60                 va_start(args, fmt);
  61                 fprintf(stderr, "00[LIB] ");
  62                 vfprintf(stderr, fmt, args);
  63                 fprintf(stderr, "\n");
  64                 va_end(args);
  65         }
  66 }
  67
  68 /**
  69  * Run the daemon and handle unix signals
  70  */
  71 static void run()
  72 {
  73         sigset_t set;
  74
  75         /* handle SIGINT, SIGHUP ans SIGTERM in this handler */
  76         sigemptyset(&set);
  77         sigaddset(&set, SIGINT);
  78         sigaddset(&set, SIGHUP);
  79         sigaddset(&set, SIGTERM);
  80         sigprocmask(SIG_BLOCK, &set, NULL);
  81
  82         while (TRUE)
  83         {
  84                 int sig;
  85                 int error;
  86
  87                 error = sigwait(&set, &sig);
  88                 if (error)
  89                 {
  90                         DBG1(DBG_DMN, "error %d while waiting for a signal", error);
  91                         return;
  92                 }
  93                 switch (sig)
  94                 {
  95                         case SIGHUP:
  96                         {
  97                                 DBG1(DBG_DMN, "signal of type SIGHUP received. Ignored");
  98                                 break;
  99                         }
 100                         case SIGINT:
 101                         {
 102                                 DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
 103                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 104                                 return;
 105                         }
 106                         case SIGTERM:
 107                         {
 108                                 DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
 109                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 110                                 return;
 111                         }
 112                         default:
 113                         {
 114                                 DBG1(DBG_DMN, "unknown signal %d received. Ignored", sig);
 115                                 break;
 116                         }
 117                 }
 118         }
 119 }
 120
 121 /**
 122  * drop daemon capabilities
 123  */
 124 static bool drop_capabilities()
 125 {
 126 #ifdef HAVE_PRCTL
 127         prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);
 128 #endif
 129
 130         if (setgid(charon->gid) != 0)
 131         {
 132                 DBG1(DBG_DMN, "change to unprivileged group failed");
 133                 return FALSE;
 134         }
 135         if (setuid(charon->uid) != 0)
 136         {
 137                 DBG1(DBG_DMN, "change to unprivileged user failed");
 138                 return FALSE;
 139         }
 140         if (!charon->drop_capabilities(charon))
 141         {
 142                 DBG1(DBG_DMN, "unable to drop daemon capabilities");
 143                 return FALSE;
 144         }
 145         return TRUE;
 146 }
 147
 148 /**
 149  * lookup UID and GID
 150  */
 151 static bool lookup_uid_gid()
 152 {
 153 #ifdef IPSEC_USER
 154         {
 155                 char buf[1024];
 156                 struct passwd passwd, *pwp;
 157
 158                 if (getpwnam_r(IPSEC_USER, &passwd, buf, sizeof(buf), &pwp) != 0 ||
 159                         pwp == NULL)
 160                 {
 161                         DBG1(DBG_DMN, "resolving user '"IPSEC_USER"' failed");
 162                         return FALSE;
 163                 }
 164                 charon->uid = pwp->pw_uid;
 165         }
 166 #endif
 167 #ifdef IPSEC_GROUP
 168         {
 169                 char buf[1024];
 170                 struct group group, *grp;
 171
 172                 if (getgrnam_r(IPSEC_GROUP, &group, buf, sizeof(buf), &grp) != 0 ||
 173                         grp == NULL)
 174                 {
 175                         DBG1(DBG_DMN, "resolving group '"IPSEC_GROUP"' failed");
 176                         return FALSE;
 177                 }
 178                 charon->gid = grp->gr_gid;
 179         }
 180 #endif
 181         return TRUE;
 182 }
 183
 184 /**
 185  * Handle SIGSEGV/SIGILL signals raised by threads
 186  */
 187 static void segv_handler(int signal)
 188 {
 189         backtrace_t *backtrace;
 190
 191         DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
 192         backtrace = backtrace_create(2);
 193         backtrace->log(backtrace, stderr);
 194         backtrace->destroy(backtrace);
 195
 196         DBG1(DBG_DMN, "killing ourself, received critical signal");
 197         abort();
 198 }
 199
 200 /**
 201  * Check/create PID file, return TRUE if already running
 202  */
 203 static bool check_pidfile()
 204 {
 205         struct stat stb;
 206         FILE *file;
 207
 208         if (stat(PID_FILE, &stb) == 0)
 209         {
 210                 file = fopen(PID_FILE, "r");
 211                 if (file)
 212                 {
 213                         char buf[64];
 214                         pid_t pid = 0;
 215
 216                         memset(buf, 0, sizeof(buf));
 217                         if (fread(buf, 1, sizeof(buf), file))
 218                         {
 219                                 pid = atoi(buf);
 220                         }
 221                         fclose(file);
 222                         if (pid && kill(pid, 0) == 0)
 223                         {       /* such a process is running */
 224                                 return TRUE;
 225                         }
 226                 }
 227                 DBG1(DBG_DMN, "removing pidfile '"PID_FILE"', process not running");
 228                 unlink(PID_FILE);
 229         }
 230
 231         /* create new pidfile */
 232         file = fopen(PID_FILE, "w");
 233         if (file)
 234         {
 235                 fprintf(file, "%d\n", getpid());
 236                 ignore_result(fchown(fileno(file), charon->uid, charon->gid));
 237                 fclose(file);
 238         }
 239         return FALSE;
 240 }
 241
 242 /**
 243  * print command line usage and exit
 244  */
 245 static void usage(const char *msg)
 246 {
 247         if (msg != NULL && *msg != '\0')
 248         {
 249                 fprintf(stderr, "%s\n", msg);
 250         }
 251         fprintf(stderr, "Usage: charon\n"
 252                                         "         [--help]\n"
 253                                         "         [--version]\n"
 254                                         "         [--use-syslog]\n"
 255                                         "         [--debug-<type> <level>]\n"
 256                                         "           <type>:  log context type (dmn|mgr|ike|chd|job|cfg|knl|net|enc|lib)\n"
 257                                         "           <level>: log verbosity (-1 = silent, 0 = audit, 1 = control,\n"
 258                                         "                                    2 = controlmore, 3 = raw, 4 = private)\n"
 259                                         "\n"
 260                    );
 261         exit(msg == NULL? 0 : 1);
 262 }
 263
 264 /**
 265  * Main function, starts the daemon.
 266  */
 267 int main(int argc, char *argv[])
 268 {
 269         struct sigaction action;
 270         bool use_syslog = FALSE;
 271         level_t levels[DBG_MAX];
 272         int group, status = SS_RC_INITIALIZATION_FAILED;
 273
 274         /* logging for library during initialization, as we have no bus yet */
 275         dbg = dbg_stderr;
 276
 277         /* initialize library */
 278         if (!library_init(NULL))
 279         {
 280                 library_deinit();
 281                 exit(SS_RC_LIBSTRONGSWAN_INTEGRITY);
 282         }
 283
 284         if (lib->integrity &&
 285                 !lib->integrity->check_file(lib->integrity, "charon", argv[0]))
 286         {
 287                 dbg_stderr(1, "integrity check of charon failed");
 288                 library_deinit();
 289                 exit(SS_RC_DAEMON_INTEGRITY);
 290         }
 291
 292         if (!libhydra_init())
 293         {
 294                 dbg_stderr(1, "initialization failed - aborting charon");
 295                 libhydra_deinit();
 296                 library_deinit();
 297                 exit(SS_RC_INITIALIZATION_FAILED);
 298         }
 299
 300         if (!libcharon_init())
 301         {
 302                 dbg_stderr(1, "initialization failed - aborting charon");
 303                 goto deinit;
 304         }
 305
 306         /* use CTRL loglevel for default */
 307         for (group = 0; group < DBG_MAX; group++)
 308         {
 309                 levels[group] = LEVEL_CTRL;
 310         }
 311
 312         /* handle arguments */
 313         for (;;)
 314         {
 315                 struct option long_opts[] = {
 316                         { "help", no_argument, NULL, 'h' },
 317                         { "version", no_argument, NULL, 'v' },
 318                         { "use-syslog", no_argument, NULL, 'l' },
 319                         /* TODO: handle "debug-all" */
 320                         { "debug-dmn", required_argument, &group, DBG_DMN },
 321                         { "debug-mgr", required_argument, &group, DBG_MGR },
 322                         { "debug-ike", required_argument, &group, DBG_IKE },
 323                         { "debug-chd", required_argument, &group, DBG_CHD },
 324                         { "debug-job", required_argument, &group, DBG_JOB },
 325                         { "debug-cfg", required_argument, &group, DBG_CFG },
 326                         { "debug-knl", required_argument, &group, DBG_KNL },
 327                         { "debug-net", required_argument, &group, DBG_NET },
 328                         { "debug-enc", required_argument, &group, DBG_ENC },
 329                         { "debug-lib", required_argument, &group, DBG_LIB },
 330                         { 0,0,0,0 }
 331                 };
 332
 333                 int c = getopt_long(argc, argv, "", long_opts, NULL);
 334                 switch (c)
 335                 {
 336                         case EOF:
 337                                 break;
 338                         case 'h':
 339                                 usage(NULL);
 340                                 break;
 341                         case 'v':
 342                                 printf("Linux strongSwan %s\n", VERSION);
 343                                 exit(0);
 344                         case 'l':
 345                                 use_syslog = TRUE;
 346                                 continue;
 347                         case 0:
 348                                 /* option is in group */
 349                                 levels[group] = atoi(optarg);
 350                                 continue;
 351                         default:
 352                                 usage("");
 353                                 break;
 354                 }
 355                 break;
 356         }
 357
 358         if (!lookup_uid_gid())
 359         {
 360                 dbg_stderr(1, "invalid uid/gid - aborting charon");
 361                 goto deinit;
 362         }
 363
 364         /* initialize daemon */
 365         if (!charon->initialize(charon, use_syslog, levels))
 366         {
 367                 DBG1(DBG_DMN, "initialization failed - aborting charon");
 368                 goto deinit;
 369         }
 370
 371         if (check_pidfile())
 372         {
 373                 DBG1(DBG_DMN, "charon already running (\""PID_FILE"\" exists)");
 374                 status = -1;
 375                 goto deinit;
 376         }
 377
 378         if (!drop_capabilities())
 379         {
 380                 DBG1(DBG_DMN, "capability dropping failed - aborting charon");
 381                 goto deinit;
 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         unlink(PID_FILE);
 408         status = 0;
 409
 410 deinit:
 411         libcharon_deinit();
 412         libhydra_deinit();
 413         library_deinit();
 414         return status;
 415 }
 416