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 #include <errno.h>
  28
  29 #include <hydra.h>
  30 #include <daemon.h>
  31 #include <library.h>
  32 #include <utils/backtrace.h>
  33 #include <threading/thread.h>
  34 #include <sa/keymat.h>
  35 #include <credentials/credential_manager.h>
  36
  37 #include "tkm.h"
  38 #include "tkm_nonceg.h"
  39 #include "tkm_diffie_hellman.h"
  40 #include "tkm_keymat.h"
  41 #include "tkm_listener.h"
  42 #include "tkm_kernel_ipsec.h"
  43 #include "tkm_public_key.h"
  44 #include "tkm_cred.h"
  45 #include "tkm_encoder.h"
  46 #include "tkm_spi_generator.h"
  47
  48 /**
  49  * TKM bus listener for IKE authorize events.
  50  */
  51 static tkm_listener_t *listener;
  52
  53 /**
  54  * PID file, in which charon-tkm stores its process id
  55  */
  56 static char *pidfile_name = NULL;
  57
  58 /**
  59  * Global reference to PID file (required to truncate, if undeletable)
  60  */
  61 static FILE *pidfile = NULL;
  62
  63 /**
  64  * Hook in library for debugging messages
  65  */
  66 extern void (*dbg) (debug_t group, level_t level, char *fmt, ...);
  67
  68 /**
  69  * Simple logging hook for library logs, using syslog output
  70  */
  71 static void dbg_syslog(debug_t group, level_t level, char *fmt, ...)
  72 {
  73         if (level <= 1)
  74         {
  75                 char buffer[8192];
  76                 va_list args;
  77
  78                 va_start(args, fmt);
  79                 /* write in memory buffer first */
  80                 vsnprintf(buffer, sizeof(buffer), fmt, args);
  81                 syslog(LOG_DAEMON|LOG_INFO, "00[%s] %s", debug_names->names[group],
  82                                 buffer);
  83                 va_end(args);
  84         }
  85 }
  86
  87 /**
  88  * Run the daemon and handle unix signals
  89  */
  90 static void run()
  91 {
  92         sigset_t set;
  93
  94         /* handle SIGINT and SIGTERM in this handler */
  95         sigemptyset(&set);
  96         sigaddset(&set, SIGINT);
  97         sigaddset(&set, SIGTERM);
  98         sigprocmask(SIG_BLOCK, &set, NULL);
  99
 100         while (TRUE)
 101         {
 102                 int sig;
 103
 104                 sig = sigwaitinfo(&set, NULL);
 105                 if (sig == -1)
 106                 {
 107                         DBG1(DBG_DMN, "waiting for signal failed: %s", strerror(errno));
 108                         return;
 109                 }
 110                 switch (sig)
 111                 {
 112                         case SIGINT:
 113                         {
 114                                 DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
 115                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 116                                 return;
 117                         }
 118                         case SIGTERM:
 119                         {
 120                                 DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
 121                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 122                                 return;
 123                         }
 124                         default:
 125                         {
 126                                 DBG1(DBG_DMN, "unknown signal %d received. Ignored", sig);
 127                                 break;
 128                         }
 129                 }
 130         }
 131 }
 132
 133 /**
 134  * Handle SIGSEGV/SIGILL signals raised by threads
 135  */
 136 static void segv_handler(int signal)
 137 {
 138         backtrace_t *backtrace;
 139
 140         DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
 141         backtrace = backtrace_create(2);
 142         backtrace->log(backtrace, stderr, TRUE);
 143         backtrace->destroy(backtrace);
 144
 145         DBG1(DBG_DMN, "killing ourself, received critical signal");
 146         abort();
 147 }
 148
 149 /**
 150  * Lookup UID and GID
 151  */
 152 static bool lookup_uid_gid()
 153 {
 154 #ifdef IPSEC_USER
 155         if (!lib->caps->resolve_uid(lib->caps, IPSEC_USER))
 156         {
 157                 return FALSE;
 158         }
 159 #endif
 160 #ifdef IPSEC_GROUP
 161         if (!lib->caps->resolve_gid(lib->caps, IPSEC_GROUP))
 162         {
 163                 return FALSE;
 164         }
 165 #endif
 166         return TRUE;
 167 }
 168
 169 /**
 170  * Check/create PID file, return TRUE if already running
 171  */
 172 static bool check_pidfile()
 173 {
 174         struct stat stb;
 175
 176         if (stat(pidfile_name, &stb) == 0)
 177         {
 178                 pidfile = fopen(pidfile_name, "r");
 179                 if (pidfile)
 180                 {
 181                         char buf[64];
 182                         pid_t pid = 0;
 183
 184                         memset(buf, 0, sizeof(buf));
 185                         if (fread(buf, 1, sizeof(buf), pidfile))
 186                         {
 187                                 buf[sizeof(buf) - 1] = '\0';
 188                                 pid = atoi(buf);
 189                         }
 190                         fclose(pidfile);
 191                         if (pid && kill(pid, 0) == 0)
 192                         {       /* such a process is running */
 193                                 return TRUE;
 194                         }
 195                 }
 196                 DBG1(DBG_DMN, "removing pidfile '%s', process not running", pidfile_name);
 197                 unlink(pidfile_name);
 198         }
 199
 200         /* create new pidfile */
 201         pidfile = fopen(pidfile_name, "w");
 202         if (pidfile)
 203         {
 204                 ignore_result(fchown(fileno(pidfile),
 205                                                          lib->caps->get_uid(lib->caps),
 206                                                          lib->caps->get_gid(lib->caps)));
 207                 fprintf(pidfile, "%d\n", getpid());
 208                 fflush(pidfile);
 209         }
 210         return FALSE;
 211 }
 212
 213 /**
 214  * Delete/truncate the PID file
 215  */
 216 static void unlink_pidfile()
 217 {
 218         /* because unlinking the PID file may fail, we truncate it to ensure the
 219          * daemon can be properly restarted.  one probable cause for this is the
 220          * combination of not running as root and the effective user lacking
 221          * permissions on the parent dir(s) of the PID file */
 222         if (pidfile)
 223         {
 224                 ignore_result(ftruncate(fileno(pidfile), 0));
 225                 fclose(pidfile);
 226         }
 227         unlink(pidfile_name);
 228 }
 229 /**
 230  * Main function, starts TKM backend.
 231  */
 232 int main(int argc, char *argv[])
 233 {
 234         char *dmn_name;
 235         if (argc > 0 && strlen(argv[0]) > 0)
 236         {
 237                 dmn_name = basename(argv[0]);
 238         }
 239         else
 240         {
 241                 dmn_name = "charon-tkm";
 242         }
 243
 244         /* TKM credential set */
 245         tkm_cred_t *creds;
 246
 247         struct sigaction action;
 248         int status = SS_RC_INITIALIZATION_FAILED;
 249
 250         /* logging for library during initialization, as we have no bus yet */
 251         dbg = dbg_syslog;
 252
 253         /* initialize library */
 254         if (!library_init(NULL, dmn_name))
 255         {
 256                 library_deinit();
 257                 exit(status);
 258         }
 259
 260         if (!libhydra_init())
 261         {
 262                 dbg_syslog(DBG_DMN, 1, "initialization failed - aborting %s", dmn_name);
 263                 libhydra_deinit();
 264                 library_deinit();
 265                 exit(status);
 266         }
 267
 268         if (!libcharon_init())
 269         {
 270                 dbg_syslog(DBG_DMN, 1, "initialization failed - aborting %s", dmn_name);
 271                 goto deinit;
 272         }
 273
 274         if (!lookup_uid_gid())
 275         {
 276                 dbg_syslog(DBG_DMN, 1, "invalid uid/gid - aborting %s", dmn_name);
 277                 goto deinit;
 278         }
 279
 280         /* the authorize hook currently does not support RFC 7427 signature auth */
 281         lib->settings->set_bool(lib->settings, "%s.signature_authentication", FALSE,
 282                                                         dmn_name);
 283
 284         /* make sure we log to the DAEMON facility by default */
 285         lib->settings->set_int(lib->settings, "%s.syslog.daemon.default",
 286                         lib->settings->get_int(lib->settings, "%s.syslog.daemon.default", 1,
 287                                                                    dmn_name), dmn_name);
 288         charon->load_loggers(charon, NULL, FALSE);
 289
 290         DBG1(DBG_DMN, "Starting charon with TKM backend (strongSwan "VERSION")");
 291
 292         /* register TKM specific plugins */
 293         static plugin_feature_t features[] = {
 294                 PLUGIN_REGISTER(NONCE_GEN, tkm_nonceg_create),
 295                         PLUGIN_PROVIDE(NONCE_GEN),
 296                 PLUGIN_REGISTER(PUBKEY, tkm_public_key_load, TRUE),
 297                         PLUGIN_PROVIDE(PUBKEY, KEY_RSA),
 298                         PLUGIN_PROVIDE(PUBKEY_VERIFY, SIGN_RSA_EMSA_PKCS1_SHA1),
 299                         PLUGIN_PROVIDE(PUBKEY_VERIFY, SIGN_RSA_EMSA_PKCS1_SHA256),
 300                 PLUGIN_CALLBACK(kernel_ipsec_register, tkm_kernel_ipsec_create),
 301                         PLUGIN_PROVIDE(CUSTOM, "kernel-ipsec"),
 302                 PLUGIN_CALLBACK(tkm_spi_generator_register, NULL),
 303                         PLUGIN_PROVIDE(CUSTOM, "tkm-spi-generator"),
 304                                 PLUGIN_DEPENDS(CUSTOM, "libcharon-sa-managers"),
 305         };
 306         lib->plugins->add_static_features(lib->plugins, "tkm-backend", features,
 307                         countof(features), TRUE, NULL, NULL);
 308
 309         if (!register_dh_mapping())
 310         {
 311                 DBG1(DBG_DMN, "no DH group mapping defined - aborting %s", dmn_name);
 312                 goto deinit;
 313         }
 314
 315         /* register TKM keymat variant */
 316         keymat_register_constructor(IKEV2, (keymat_constructor_t)tkm_keymat_create);
 317
 318         /* initialize daemon */
 319         if (!charon->initialize(charon, PLUGINS))
 320         {
 321                 DBG1(DBG_DMN, "initialization failed - aborting %s", dmn_name);
 322                 goto deinit;
 323         }
 324         lib->plugins->status(lib->plugins, LEVEL_CTRL);
 325
 326         /* set global pidfile name depending on daemon name */
 327         if (asprintf(&pidfile_name, IPSEC_PIDDIR"/%s.pid", dmn_name) < 0)
 328         {
 329                 DBG1(DBG_DMN, "unable to set pidfile name - aborting %s", dmn_name);
 330                 goto deinit;
 331         };
 332
 333         if (check_pidfile())
 334         {
 335                 DBG1(DBG_DMN, "%s already running (\"%s\" exists)", dmn_name,
 336                          pidfile_name);
 337                 goto deinit;
 338         }
 339
 340         if (!lib->caps->drop(lib->caps))
 341         {
 342                 DBG1(DBG_DMN, "capability dropping failed - aborting %s", dmn_name);
 343                 goto deinit;
 344         }
 345
 346         /* initialize TKM client */
 347         if (!tkm_init())
 348         {
 349                 DBG1(DBG_DMN, "init of TKM client failed - aborting %s", dmn_name);
 350                 goto deinit;
 351         }
 352
 353         /* register TKM authorization hook */
 354         listener = tkm_listener_create();
 355         charon->bus->add_listener(charon->bus, &listener->listener);
 356
 357         /* register TKM credential set */
 358         creds = tkm_cred_create();
 359         lib->credmgr->add_set(lib->credmgr, (credential_set_t*)creds);
 360
 361         /* register TKM credential encoder */
 362         lib->encoding->add_encoder(lib->encoding, tkm_encoder_encode);
 363
 364         /* add handler for SEGV and ILL,
 365          * INT and TERM are handled by sigwaitinfo() in run() */
 366         action.sa_handler = segv_handler;
 367         action.sa_flags = 0;
 368         sigemptyset(&action.sa_mask);
 369         sigaddset(&action.sa_mask, SIGINT);
 370         sigaddset(&action.sa_mask, SIGTERM);
 371         sigaction(SIGSEGV, &action, NULL);
 372         sigaction(SIGILL, &action, NULL);
 373         sigaction(SIGBUS, &action, NULL);
 374         action.sa_handler = SIG_IGN;
 375         sigaction(SIGPIPE, &action, NULL);
 376
 377         pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
 378
 379         /* start daemon (i.e. the threads in the thread-pool) */
 380         charon->start(charon);
 381
 382         /* main thread goes to run loop */
 383         run();
 384
 385         unlink_pidfile();
 386         status = 0;
 387         charon->bus->remove_listener(charon->bus, &listener->listener);
 388         listener->destroy(listener);
 389         creds->destroy(creds);
 390         lib->encoding->remove_encoder(lib->encoding, tkm_encoder_encode);
 391
 392 deinit:
 393         destroy_dh_mapping();
 394         libcharon_deinit();
 395         libhydra_deinit();
 396         library_deinit();
 397         tkm_deinit();
 398         return status;
 399 }