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