src/charon-tkm/src/charon-tkm.c

   1 /*
   2  * Copyright (C) 2012 Tobias Brunner
   3  * Copyright (C) 2012 Reto Buerki
   4  * Copyright (C) 2012 Adrian-Ken Rueegsegger
   5  * Hochschule fuer Technik Rapperswil
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 #define _GNU_SOURCE
  19
  20 #include <stdio.h>
  21 #include <syslog.h>
  22 #include <signal.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <libgen.h>
  27
  28 #include <hydra.h>
  29 #include <daemon.h>
  30
  31 #include <library.h>
  32 #include <utils/backtrace.h>
  33 #include <threading/thread.h>
  34
  35 #include "tkm.h"
  36 #include "tkm_nonceg.h"
  37
  38 /**
  39  * PID file, in which charon-tkm stores its process id
  40  */
  41 static char *pidfile_name = NULL;
  42
  43 /**
  44  * Global reference to PID file (required to truncate, if undeletable)
  45  */
  46 static FILE *pidfile = NULL;
  47
  48 /**
  49  * Hook in library for debugging messages
  50  */
  51 extern void (*dbg) (debug_t group, level_t level, char *fmt, ...);
  52
  53 /**
  54  * Simple logging hook for library logs, using syslog output
  55  */
  56 static void dbg_syslog(debug_t group, level_t level, char *fmt, ...)
  57 {
  58         if (level <= 1)
  59         {
  60                 char buffer[8192];
  61                 va_list args;
  62
  63                 va_start(args, fmt);
  64                 /* write in memory buffer first */
  65                 vsnprintf(buffer, sizeof(buffer), fmt, args);
  66                 syslog(LOG_DAEMON|LOG_INFO, "00[%s] %s", debug_names->names[group],
  67                                 buffer);
  68                 va_end(args);
  69         }
  70 }
  71
  72 /**
  73  * Run the daemon and handle unix signals
  74  */
  75 static void run()
  76 {
  77         sigset_t set;
  78
  79         /* handle SIGINT and SIGTERM in this handler */
  80         sigemptyset(&set);
  81         sigaddset(&set, SIGINT);
  82         sigaddset(&set, SIGTERM);
  83         sigprocmask(SIG_BLOCK, &set, NULL);
  84
  85         while (TRUE)
  86         {
  87                 int sig;
  88                 int error;
  89
  90                 error = sigwait(&set, &sig);
  91                 if (error)
  92                 {
  93                         DBG1(DBG_DMN, "error %d while waiting for a signal", error);
  94                         return;
  95                 }
  96                 switch (sig)
  97                 {
  98                         case SIGINT:
  99                         {
 100                                 DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
 101                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 102                                 return;
 103                         }
 104                         case SIGTERM:
 105                         {
 106                                 DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
 107                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 108                                 return;
 109                         }
 110                         default:
 111                         {
 112                                 DBG1(DBG_DMN, "unknown signal %d received. Ignored", sig);
 113                                 break;
 114                         }
 115                 }
 116         }
 117 }
 118
 119 /**
 120  * Handle SIGSEGV/SIGILL signals raised by threads
 121  */
 122 static void segv_handler(int signal)
 123 {
 124         backtrace_t *backtrace;
 125
 126         DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
 127         backtrace = backtrace_create(2);
 128         backtrace->log(backtrace, stderr, TRUE);
 129         backtrace->destroy(backtrace);
 130
 131         DBG1(DBG_DMN, "killing ourself, received critical signal");
 132         abort();
 133 }
 134
 135 /**
 136  * Lookup UID and GID
 137  */
 138 static bool lookup_uid_gid()
 139 {
 140 #ifdef IPSEC_USER
 141         if (!charon->caps->resolve_uid(charon->caps, IPSEC_USER))
 142         {
 143                 return FALSE;
 144         }
 145 #endif
 146 #ifdef IPSEC_GROUP
 147         if (!charon->caps->resolve_gid(charon->caps, IPSEC_GROUP))
 148         {
 149                 return FALSE;
 150         }
 151 #endif
 152         return TRUE;
 153 }
 154
 155 /**
 156  * Check/create PID file, return TRUE if already running
 157  */
 158 static bool check_pidfile()
 159 {
 160         struct stat stb;
 161
 162         if (stat(pidfile_name, &stb) == 0)
 163         {
 164                 pidfile = fopen(pidfile_name, "r");
 165                 if (pidfile)
 166                 {
 167                         char buf[64];
 168                         pid_t pid = 0;
 169
 170                         memset(buf, 0, sizeof(buf));
 171                         if (fread(buf, 1, sizeof(buf), pidfile))
 172                         {
 173                                 buf[sizeof(buf) - 1] = '\0';
 174                                 pid = atoi(buf);
 175                         }
 176                         fclose(pidfile);
 177                         if (pid && kill(pid, 0) == 0)
 178                         {       /* such a process is running */
 179                                 return TRUE;
 180                         }
 181                 }
 182                 DBG1(DBG_DMN, "removing pidfile '%s', process not running", pidfile_name);
 183                 unlink(pidfile_name);
 184         }
 185
 186         /* create new pidfile */
 187         pidfile = fopen(pidfile_name, "w");
 188         if (pidfile)
 189         {
 190                 ignore_result(fchown(fileno(pidfile),
 191                                                          charon->caps->get_uid(charon->caps),
 192                                                          charon->caps->get_gid(charon->caps)));
 193                 fprintf(pidfile, "%d\n", getpid());
 194                 fflush(pidfile);
 195         }
 196         return FALSE;
 197 }
 198
 199 /**
 200  * Delete/truncate the PID file
 201  */
 202 static void unlink_pidfile()
 203 {
 204         /* because unlinking the PID file may fail, we truncate it to ensure the
 205          * daemon can be properly restarted.  one probable cause for this is the
 206          * combination of not running as root and the effective user lacking
 207          * permissions on the parent dir(s) of the PID file */
 208         if (pidfile)
 209         {
 210                 ignore_result(ftruncate(fileno(pidfile), 0));
 211                 fclose(pidfile);
 212         }
 213         unlink(pidfile_name);
 214 }
 215 /**
 216  * Main function, starts TKM backend.
 217  */
 218 int main(int argc, char *argv[])
 219 {
 220         char *dmn_name;
 221         if (argc > 0 && strlen(argv[0]) > 0)
 222         {
 223                 dmn_name = basename(argv[0]);
 224         }
 225         else
 226         {
 227                 dmn_name = "charon-tkm";
 228         }
 229
 230         struct sigaction action;
 231         int status = SS_RC_INITIALIZATION_FAILED;
 232
 233         /* logging for library during initialization, as we have no bus yet */
 234         dbg = dbg_syslog;
 235
 236         /* initialize library */
 237         if (!library_init(NULL))
 238         {
 239                 library_deinit();
 240                 exit(status);
 241         }
 242
 243         if (!libhydra_init(dmn_name))
 244         {
 245                 dbg_syslog(DBG_DMN, 1, "initialization failed - aborting %s", dmn_name);
 246                 libhydra_deinit();
 247                 library_deinit();
 248                 exit(status);
 249         }
 250
 251         if (!libcharon_init(dmn_name))
 252         {
 253                 dbg_syslog(DBG_DMN, 1, "initialization failed - aborting %s", dmn_name);
 254                 goto deinit;
 255         }
 256
 257         if (!lookup_uid_gid())
 258         {
 259                 dbg_syslog(DBG_DMN, 1, "invalid uid/gid - aborting %s", dmn_name);
 260                 goto deinit;
 261         }
 262
 263         /* make sure we log to the DAEMON facility by default */
 264         lib->settings->set_int(lib->settings, "%s.syslog.daemon.default",
 265                         lib->settings->get_int(lib->settings, "%s.syslog.daemon.default", 1,
 266                                                                    dmn_name), dmn_name);
 267         charon->load_loggers(charon, NULL, FALSE);
 268
 269         DBG1(DBG_DMN, "Starting charon with TKM backend (strongSwan "VERSION")");
 270
 271         /* register TKM specific plugins */
 272         static plugin_feature_t features[] = {
 273                 PLUGIN_REGISTER(NONCE_GEN, tkm_nonceg_create),
 274                 PLUGIN_PROVIDE(NONCE_GEN)
 275         };
 276         lib->plugins->add_static_features(lib->plugins, "tkm-backend", features,
 277                         countof(features), TRUE);
 278
 279         /* initialize daemon */
 280         if (!charon->initialize(charon, PLUGINS))
 281         {
 282                 DBG1(DBG_DMN, "initialization failed - aborting %s", dmn_name);
 283                 goto deinit;
 284         }
 285
 286         /* set global pidfile name depending on daemon name */
 287         if (asprintf(&pidfile_name, IPSEC_PIDDIR"/%s.pid", dmn_name) < 0)
 288         {
 289                 DBG1(DBG_DMN, "unable to set pidfile name - aborting %s", dmn_name);
 290                 goto deinit;
 291         };
 292
 293         if (check_pidfile())
 294         {
 295                 DBG1(DBG_DMN, "%s already running (\"%s\" exists)", dmn_name,
 296                          pidfile_name);
 297                 goto deinit;
 298         }
 299
 300         if (!charon->caps->drop(charon->caps))
 301         {
 302                 DBG1(DBG_DMN, "capability dropping failed - aborting %s", dmn_name);
 303                 goto deinit;
 304         }
 305
 306         /* initialize TKM client */
 307         if (!tkm_init())
 308         {
 309                 DBG1(DBG_DMN, "init of TKM client failed - aborting %s", dmn_name);
 310                 goto deinit;
 311         }
 312
 313         /* add handler for SEGV and ILL,
 314          * INT and TERM are handled by sigwait() in run() */
 315         action.sa_handler = segv_handler;
 316         action.sa_flags = 0;
 317         sigemptyset(&action.sa_mask);
 318         sigaddset(&action.sa_mask, SIGINT);
 319         sigaddset(&action.sa_mask, SIGTERM);
 320         sigaction(SIGSEGV, &action, NULL);
 321         sigaction(SIGILL, &action, NULL);
 322         sigaction(SIGBUS, &action, NULL);
 323         action.sa_handler = SIG_IGN;
 324         sigaction(SIGPIPE, &action, NULL);
 325
 326         pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
 327
 328         /* start daemon (i.e. the threads in the thread-pool) */
 329         charon->start(charon);
 330
 331         /* main thread goes to run loop */
 332         run();
 333
 334         unlink_pidfile();
 335         status = 0;
 336
 337 deinit:
 338         libcharon_deinit();
 339         libhydra_deinit();
 340         library_deinit();
 341         tkm_deinit();
 342         return status;
 343 }