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