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

   1 /*
   2  * Copyright (C) 2012-2017 Tobias Brunner
   3  * Copyright (C) 2012 Reto Buerki
   4  * Copyright (C) 2012 Adrian-Ken Rueegsegger
   5  * HSR 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 <fcntl.h>
  28 #include <errno.h>
  29
  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
  47 /**
  48  * TKM bus listener for IKE authorize events.
  49  */
  50 static tkm_listener_t *listener;
  51
  52 /**
  53  * Name of the daemon
  54  */
  55 static char *dmn_name;
  56
  57 /**
  58  * PID file, in which charon-tkm stores its process id
  59  */
  60 static char *pidfile_name = NULL;
  61
  62 /**
  63  * Global reference to PID file (required to truncate, if undeletable)
  64  */
  65 static FILE *pidfile = NULL;
  66
  67 /**
  68  * Hook in library for debugging messages
  69  */
  70 extern void (*dbg) (debug_t group, level_t level, char *fmt, ...);
  71
  72 /**
  73  * Simple logging hook for library logs, using syslog output
  74  */
  75 static void dbg_syslog(debug_t group, level_t level, char *fmt, ...)
  76 {
  77         if (level <= 1)
  78         {
  79                 char buffer[8192];
  80                 va_list args;
  81
  82                 va_start(args, fmt);
  83                 /* write in memory buffer first */
  84                 vsnprintf(buffer, sizeof(buffer), fmt, args);
  85                 syslog(LOG_DAEMON|LOG_INFO, "00[%s] %s", debug_names->names[group],
  86                                 buffer);
  87                 va_end(args);
  88         }
  89 }
  90
  91 /**
  92  * Run the daemon and handle unix signals
  93  */
  94 static void run()
  95 {
  96         sigset_t set;
  97
  98         /* handle SIGINT and SIGTERM in this handler */
  99         sigemptyset(&set);
 100         sigaddset(&set, SIGINT);
 101         sigaddset(&set, SIGTERM);
 102         sigprocmask(SIG_BLOCK, &set, NULL);
 103
 104         while (TRUE)
 105         {
 106                 int sig;
 107
 108                 sig = sigwaitinfo(&set, NULL);
 109                 if (sig == -1)
 110                 {
 111                         if (errno == EINTR)
 112                         {       /* ignore signals we didn't wait for */
 113                                 continue;
 114                         }
 115                         DBG1(DBG_DMN, "waiting for signal failed: %s", strerror(errno));
 116                         return;
 117                 }
 118                 switch (sig)
 119                 {
 120                         case SIGINT:
 121                         {
 122                                 DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
 123                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 124                                 return;
 125                         }
 126                         case SIGTERM:
 127                         {
 128                                 DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
 129                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 130                                 return;
 131                         }
 132                 }
 133         }
 134 }
 135
 136 #ifndef DISABLE_SIGNAL_HANDLER
 137 /**
 138  * Handle SIGSEGV/SIGILL signals raised by threads
 139  */
 140 static void segv_handler(int signal)
 141 {
 142         backtrace_t *backtrace;
 143
 144         DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
 145         backtrace = backtrace_create(2);
 146         backtrace->log(backtrace, stderr, TRUE);
 147         backtrace->destroy(backtrace);
 148
 149         DBG1(DBG_DMN, "killing ourself, received critical signal");
 150         abort();
 151 }
 152 #endif /* DISABLE_SIGNAL_HANDLER */
 153
 154 /**
 155  * Lookup UID and GID
 156  */
 157 static bool lookup_uid_gid()
 158 {
 159 #ifdef IPSEC_USER
 160         if (!lib->caps->resolve_uid(lib->caps, IPSEC_USER))
 161         {
 162                 return FALSE;
 163         }
 164 #endif
 165 #ifdef IPSEC_GROUP
 166         if (!lib->caps->resolve_gid(lib->caps, IPSEC_GROUP))
 167         {
 168                 return FALSE;
 169         }
 170 #endif
 171         return TRUE;
 172 }
 173
 174 /**
 175  * Check/create PID file, return TRUE if already running
 176  */
 177 static bool check_pidfile()
 178 {
 179         struct stat stb;
 180
 181         if (stat(pidfile_name, &stb) == 0)
 182         {
 183                 pidfile = fopen(pidfile_name, "r");
 184                 if (pidfile)
 185                 {
 186                         char buf[64];
 187                         pid_t pid = 0;
 188
 189                         memset(buf, 0, sizeof(buf));
 190                         if (fread(buf, 1, sizeof(buf), pidfile))
 191                         {
 192                                 buf[sizeof(buf) - 1] = '\0';
 193                                 pid = atoi(buf);
 194                         }
 195                         fclose(pidfile);
 196                         pidfile = NULL;
 197                         if (pid && pid != getpid() && kill(pid, 0) == 0)
 198                         {
 199                                 DBG1(DBG_DMN, "%s already running ('%s' exists)", dmn_name,
 200                                          pidfile_name);
 201                                 return TRUE;
 202                         }
 203                 }
 204                 DBG1(DBG_DMN, "removing pidfile '%s', process not running", pidfile_name);
 205                 unlink(pidfile_name);
 206         }
 207
 208         /* create new pidfile */
 209         pidfile = fopen(pidfile_name, "w");
 210         if (pidfile)
 211         {
 212                 int fd;
 213
 214                 fd = fileno(pidfile);
 215                 if (fd == -1)
 216                 {
 217                         DBG1(DBG_DMN, "unable to determine fd for '%s'", pidfile_name);
 218                         return TRUE;
 219                 }
 220                 if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
 221                 {
 222                         DBG1(DBG_LIB, "setting FD_CLOEXEC for '%s' failed: %s",
 223                                  pidfile_name, strerror(errno));
 224                 }
 225                 ignore_result(fchown(fd,
 226                                                          lib->caps->get_uid(lib->caps),
 227                                                          lib->caps->get_gid(lib->caps)));
 228                 fprintf(pidfile, "%d\n", getpid());
 229                 fflush(pidfile);
 230                 return FALSE;
 231         }
 232         else
 233         {
 234                 DBG1(DBG_DMN, "unable to create pidfile '%s'", pidfile_name);
 235                 return TRUE;
 236         }
 237 }
 238
 239 /**
 240  * Delete/truncate the PID file
 241  */
 242 static void unlink_pidfile()
 243 {
 244         /* because unlinking the PID file may fail, we truncate it to ensure the
 245          * daemon can be properly restarted.  one probable cause for this is the
 246          * combination of not running as root and the effective user lacking
 247          * permissions on the parent dir(s) of the PID file */
 248         if (pidfile)
 249         {
 250                 ignore_result(ftruncate(fileno(pidfile), 0));
 251                 fclose(pidfile);
 252                 unlink(pidfile_name);
 253         }
 254 }
 255
 256 /**
 257  * Main function, starts TKM backend.
 258  */
 259 int main(int argc, char *argv[])
 260 {
 261         if (argc > 0 && strlen(argv[0]) > 0)
 262         {
 263                 dmn_name = basename(argv[0]);
 264         }
 265         else
 266         {
 267                 dmn_name = "charon-tkm";
 268         }
 269
 270         /* TKM credential set */
 271         tkm_cred_t *creds;
 272
 273         struct sigaction action;
 274         int status = SS_RC_INITIALIZATION_FAILED;
 275
 276         /* logging for library during initialization, as we have no bus yet */
 277         dbg = dbg_syslog;
 278
 279         /* initialize library */
 280         if (!library_init(NULL, dmn_name))
 281         {
 282                 library_deinit();
 283                 exit(status);
 284         }
 285
 286         if (!libcharon_init())
 287         {
 288                 dbg_syslog(DBG_DMN, 1, "initialization failed - aborting %s", dmn_name);
 289                 goto deinit;
 290         }
 291
 292         if (!lookup_uid_gid())
 293         {
 294                 dbg_syslog(DBG_DMN, 1, "invalid uid/gid - aborting %s", dmn_name);
 295                 goto deinit;
 296         }
 297
 298         /* the authorize hook currently does not support RFC 7427 signature auth */
 299         lib->settings->set_bool(lib->settings, "%s.signature_authentication", FALSE,
 300                                                         dmn_name);
 301
 302         /* make sure we log to the DAEMON facility by default */
 303         lib->settings->set_int(lib->settings, "%s.syslog.daemon.default",
 304                         lib->settings->get_int(lib->settings, "%s.syslog.daemon.default", 1,
 305                                                                    dmn_name), dmn_name);
 306         charon->load_loggers(charon);
 307
 308         DBG1(DBG_DMN, "Starting charon with TKM backend (strongSwan "VERSION")");
 309
 310         /* register TKM specific plugins */
 311         static plugin_feature_t features[] = {
 312                 PLUGIN_REGISTER(NONCE_GEN, tkm_nonceg_create),
 313                         PLUGIN_PROVIDE(NONCE_GEN),
 314                 PLUGIN_REGISTER(PUBKEY, tkm_public_key_load, TRUE),
 315                         PLUGIN_PROVIDE(PUBKEY, KEY_RSA),
 316                         PLUGIN_PROVIDE(PUBKEY_VERIFY, SIGN_RSA_EMSA_PKCS1_SHA1),
 317                         PLUGIN_PROVIDE(PUBKEY_VERIFY, SIGN_RSA_EMSA_PKCS1_SHA2_256),
 318                 PLUGIN_CALLBACK(kernel_ipsec_register, tkm_kernel_ipsec_create),
 319                         PLUGIN_PROVIDE(CUSTOM, "kernel-ipsec"),
 320         };
 321         lib->plugins->add_static_features(lib->plugins, "tkm-backend", features,
 322                         countof(features), TRUE, NULL, NULL);
 323
 324         if (!register_dh_mapping())
 325         {
 326                 DBG1(DBG_DMN, "no DH group mapping defined - aborting %s", dmn_name);
 327                 goto deinit;
 328         }
 329
 330         /* register TKM keymat variant */
 331         keymat_register_constructor(IKEV2, (keymat_constructor_t)tkm_keymat_create);
 332
 333         /* initialize daemon */
 334         if (!charon->initialize(charon, PLUGINS))
 335         {
 336                 DBG1(DBG_DMN, "initialization failed - aborting %s", dmn_name);
 337                 goto deinit;
 338         }
 339         lib->plugins->status(lib->plugins, LEVEL_CTRL);
 340
 341         /* set global pidfile name depending on daemon name */
 342         if (asprintf(&pidfile_name, IPSEC_PIDDIR"/%s.pid", dmn_name) < 0)
 343         {
 344                 DBG1(DBG_DMN, "unable to set pidfile name - aborting %s", dmn_name);
 345                 goto deinit;
 346         };
 347
 348         if (check_pidfile())
 349         {
 350                 goto deinit;
 351         }
 352
 353         if (!lib->caps->drop(lib->caps))
 354         {
 355                 DBG1(DBG_DMN, "capability dropping failed - aborting %s", dmn_name);
 356                 goto deinit;
 357         }
 358
 359         /* initialize TKM client */
 360         if (!tkm_init())
 361         {
 362                 DBG1(DBG_DMN, "init of TKM client failed - aborting %s", dmn_name);
 363                 goto deinit;
 364         }
 365
 366         /* register TKM authorization hook */
 367         listener = tkm_listener_create();
 368         charon->bus->add_listener(charon->bus, &listener->listener);
 369
 370         /* register TKM credential set */
 371         creds = tkm_cred_create();
 372         lib->credmgr->add_set(lib->credmgr, (credential_set_t*)creds);
 373
 374         /* register TKM credential encoder */
 375         lib->encoding->add_encoder(lib->encoding, tkm_encoder_encode);
 376
 377         /* add handler for fatal signals,
 378          * INT and TERM are handled by sigwaitinfo() in run() */
 379         action.sa_flags = 0;
 380         sigemptyset(&action.sa_mask);
 381         sigaddset(&action.sa_mask, SIGINT);
 382         sigaddset(&action.sa_mask, SIGTERM);
 383
 384         /* optionally let the external system handle fatal signals */
 385 #ifndef DISABLE_SIGNAL_HANDLER
 386         action.sa_handler = segv_handler;
 387         sigaction(SIGSEGV, &action, NULL);
 388         sigaction(SIGILL, &action, NULL);
 389         sigaction(SIGBUS, &action, NULL);
 390 #endif /* DISABLE_SIGNAL_HANDLER */
 391
 392         action.sa_handler = SIG_IGN;
 393         sigaction(SIGPIPE, &action, NULL);
 394
 395         pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
 396
 397         /* start daemon (i.e. the threads in the thread-pool) */
 398         charon->start(charon);
 399
 400         /* main thread goes to run loop */
 401         run();
 402
 403         status = 0;
 404         charon->bus->remove_listener(charon->bus, &listener->listener);
 405         listener->destroy(listener);
 406         creds->destroy(creds);
 407         lib->encoding->remove_encoder(lib->encoding, tkm_encoder_encode);
 408
 409 deinit:
 410         destroy_dh_mapping();
 411         libcharon_deinit();
 412         tkm_deinit();
 413         unlink_pidfile();
 414         free(pidfile_name);
 415         library_deinit();
 416         return status;
 417 }