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 #include <plugins/kernel_netlink/kernel_netlink_net.h>
  31 #include <library.h>
  32 #include <utils/backtrace.h>
  33 #include <threading/thread.h>
  34 #include <sa/keymat.h>
  35 #include <credentials/sets/mem_cred.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_private_key.h"
  45
  46 /**
  47  * TKM bus listener for IKE authorize events.
  48  */
  49 static tkm_listener_t *listener;
  50
  51 /**
  52  * PID file, in which charon-tkm stores its process id
  53  */
  54 static char *pidfile_name = NULL;
  55
  56 /**
  57  * Global reference to PID file (required to truncate, if undeletable)
  58  */
  59 static FILE *pidfile = NULL;
  60
  61 /**
  62  * Hook in library for debugging messages
  63  */
  64 extern void (*dbg) (debug_t group, level_t level, char *fmt, ...);
  65
  66 /**
  67  * Simple logging hook for library logs, using syslog output
  68  */
  69 static void dbg_syslog(debug_t group, level_t level, char *fmt, ...)
  70 {
  71         if (level <= 1)
  72         {
  73                 char buffer[8192];
  74                 va_list args;
  75
  76                 va_start(args, fmt);
  77                 /* write in memory buffer first */
  78                 vsnprintf(buffer, sizeof(buffer), fmt, args);
  79                 syslog(LOG_DAEMON|LOG_INFO, "00[%s] %s", debug_names->names[group],
  80                                 buffer);
  81                 va_end(args);
  82         }
  83 }
  84
  85 /**
  86  * Run the daemon and handle unix signals
  87  */
  88 static void run()
  89 {
  90         sigset_t set;
  91
  92         /* handle SIGINT and SIGTERM in this handler */
  93         sigemptyset(&set);
  94         sigaddset(&set, SIGINT);
  95         sigaddset(&set, SIGTERM);
  96         sigprocmask(SIG_BLOCK, &set, NULL);
  97
  98         while (TRUE)
  99         {
 100                 int sig;
 101                 int error;
 102
 103                 error = sigwait(&set, &sig);
 104                 if (error)
 105                 {
 106                         DBG1(DBG_DMN, "error %d while waiting for a signal", error);
 107                         return;
 108                 }
 109                 switch (sig)
 110                 {
 111                         case SIGINT:
 112                         {
 113                                 DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
 114                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 115                                 return;
 116                         }
 117                         case SIGTERM:
 118                         {
 119                                 DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
 120                                 charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
 121                                 return;
 122                         }
 123                         default:
 124                         {
 125                                 DBG1(DBG_DMN, "unknown signal %d received. Ignored", sig);
 126                                 break;
 127                         }
 128                 }
 129         }
 130 }
 131
 132 /**
 133  * Handle SIGSEGV/SIGILL signals raised by threads
 134  */
 135 static void segv_handler(int signal)
 136 {
 137         backtrace_t *backtrace;
 138
 139         DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
 140         backtrace = backtrace_create(2);
 141         backtrace->log(backtrace, stderr, TRUE);
 142         backtrace->destroy(backtrace);
 143
 144         DBG1(DBG_DMN, "killing ourself, received critical signal");
 145         abort();
 146 }
 147
 148 /**
 149  * Lookup UID and GID
 150  */
 151 static bool lookup_uid_gid()
 152 {
 153 #ifdef IPSEC_USER
 154         if (!charon->caps->resolve_uid(charon->caps, IPSEC_USER))
 155         {
 156                 return FALSE;
 157         }
 158 #endif
 159 #ifdef IPSEC_GROUP
 160         if (!charon->caps->resolve_gid(charon->caps, IPSEC_GROUP))
 161         {
 162                 return FALSE;
 163         }
 164 #endif
 165         return TRUE;
 166 }
 167
 168 /**
 169  * Check/create PID file, return TRUE if already running
 170  */
 171 static bool check_pidfile()
 172 {
 173         struct stat stb;
 174
 175         if (stat(pidfile_name, &stb) == 0)
 176         {
 177                 pidfile = fopen(pidfile_name, "r");
 178                 if (pidfile)
 179                 {
 180                         char buf[64];
 181                         pid_t pid = 0;
 182
 183                         memset(buf, 0, sizeof(buf));
 184                         if (fread(buf, 1, sizeof(buf), pidfile))
 185                         {
 186                                 buf[sizeof(buf) - 1] = '\0';
 187                                 pid = atoi(buf);
 188                         }
 189                         fclose(pidfile);
 190                         if (pid && kill(pid, 0) == 0)
 191                         {       /* such a process is running */
 192                                 return TRUE;
 193                         }
 194                 }
 195                 DBG1(DBG_DMN, "removing pidfile '%s', process not running", pidfile_name);
 196                 unlink(pidfile_name);
 197         }
 198
 199         /* create new pidfile */
 200         pidfile = fopen(pidfile_name, "w");
 201         if (pidfile)
 202         {
 203                 ignore_result(fchown(fileno(pidfile),
 204                                                          charon->caps->get_uid(charon->caps),
 205                                                          charon->caps->get_gid(charon->caps)));
 206                 fprintf(pidfile, "%d\n", getpid());
 207                 fflush(pidfile);
 208         }
 209         return FALSE;
 210 }
 211
 212 /**
 213  * Delete/truncate the PID file
 214  */
 215 static void unlink_pidfile()
 216 {
 217         /* because unlinking the PID file may fail, we truncate it to ensure the
 218          * daemon can be properly restarted.  one probable cause for this is the
 219          * combination of not running as root and the effective user lacking
 220          * permissions on the parent dir(s) of the PID file */
 221         if (pidfile)
 222         {
 223                 ignore_result(ftruncate(fileno(pidfile), 0));
 224                 fclose(pidfile);
 225         }
 226         unlink(pidfile_name);
 227 }
 228 /**
 229  * Main function, starts TKM backend.
 230  */
 231 int main(int argc, char *argv[])
 232 {
 233         char *dmn_name;
 234         if (argc > 0 && strlen(argv[0]) > 0)
 235         {
 236                 dmn_name = basename(argv[0]);
 237         }
 238         else
 239         {
 240                 dmn_name = "charon-tkm";
 241         }
 242
 243         /* credential set and TKM private key */
 244         mem_cred_t *creds;
 245         tkm_private_key_t *key;
 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))
 255         {
 256                 library_deinit();
 257                 exit(status);
 258         }
 259
 260         if (!libhydra_init(dmn_name))
 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(dmn_name))
 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         /* make sure we log to the DAEMON facility by default */
 281         lib->settings->set_int(lib->settings, "%s.syslog.daemon.default",
 282                         lib->settings->get_int(lib->settings, "%s.syslog.daemon.default", 1,
 283                                                                    dmn_name), dmn_name);
 284         charon->load_loggers(charon, NULL, FALSE);
 285
 286         DBG1(DBG_DMN, "Starting charon with TKM backend (strongSwan "VERSION")");
 287
 288         /* register TKM specific plugins */
 289         static plugin_feature_t features[] = {
 290                 PLUGIN_REGISTER(NONCE_GEN, tkm_nonceg_create),
 291                         PLUGIN_PROVIDE(NONCE_GEN),
 292                 PLUGIN_REGISTER(DH, tkm_diffie_hellman_create),
 293                         PLUGIN_PROVIDE(DH, MODP_3072_BIT),
 294                         PLUGIN_PROVIDE(DH, MODP_4096_BIT),
 295                 PLUGIN_REGISTER(PUBKEY, tkm_public_key_load, TRUE),
 296                         PLUGIN_PROVIDE(PUBKEY, KEY_RSA),
 297                         PLUGIN_PROVIDE(PUBKEY_VERIFY, SIGN_RSA_EMSA_PKCS1_SHA1),
 298                         PLUGIN_PROVIDE(PUBKEY_VERIFY, SIGN_RSA_EMSA_PKCS1_SHA256),
 299                 PLUGIN_CALLBACK(kernel_ipsec_register, tkm_kernel_ipsec_create),
 300                         PLUGIN_PROVIDE(CUSTOM, "kernel-ipsec"),
 301                         PLUGIN_DEPENDS(RNG, RNG_WEAK),
 302                 PLUGIN_CALLBACK(kernel_net_register, kernel_netlink_net_create),
 303                         PLUGIN_PROVIDE(CUSTOM, "kernel-net"),
 304
 305         };
 306         lib->plugins->add_static_features(lib->plugins, "tkm-backend", features,
 307                         countof(features), TRUE);
 308
 309         /* register TKM keymat variant */
 310         keymat_register_constructor(IKEV2, (keymat_constructor_t)tkm_keymat_create);
 311
 312         /* initialize daemon */
 313         if (!charon->initialize(charon, PLUGINS))
 314         {
 315                 DBG1(DBG_DMN, "initialization failed - aborting %s", dmn_name);
 316                 goto deinit;
 317         }
 318
 319         /* set global pidfile name depending on daemon name */
 320         if (asprintf(&pidfile_name, IPSEC_PIDDIR"/%s.pid", dmn_name) < 0)
 321         {
 322                 DBG1(DBG_DMN, "unable to set pidfile name - aborting %s", dmn_name);
 323                 goto deinit;
 324         };
 325
 326         if (check_pidfile())
 327         {
 328                 DBG1(DBG_DMN, "%s already running (\"%s\" exists)", dmn_name,
 329                          pidfile_name);
 330                 goto deinit;
 331         }
 332
 333         if (!charon->caps->drop(charon->caps))
 334         {
 335                 DBG1(DBG_DMN, "capability dropping failed - aborting %s", dmn_name);
 336                 goto deinit;
 337         }
 338
 339         /* initialize TKM client */
 340         if (!tkm_init())
 341         {
 342                 DBG1(DBG_DMN, "init of TKM client failed - aborting %s", dmn_name);
 343                 goto deinit;
 344         }
 345
 346         /* register TKM authorization hook */
 347         listener = tkm_listener_create();
 348         charon->bus->add_listener(charon->bus, &listener->listener);
 349
 350         /* register TKM private key */
 351         creds = mem_cred_create();
 352         key = tkm_private_key_init();
 353         creds->add_key(creds, (private_key_t *)key);
 354         lib->credmgr->add_set(lib->credmgr, (credential_set_t*)creds);
 355
 356         /* add handler for SEGV and ILL,
 357          * INT and TERM are handled by sigwait() in run() */
 358         action.sa_handler = segv_handler;
 359         action.sa_flags = 0;
 360         sigemptyset(&action.sa_mask);
 361         sigaddset(&action.sa_mask, SIGINT);
 362         sigaddset(&action.sa_mask, SIGTERM);
 363         sigaction(SIGSEGV, &action, NULL);
 364         sigaction(SIGILL, &action, NULL);
 365         sigaction(SIGBUS, &action, NULL);
 366         action.sa_handler = SIG_IGN;
 367         sigaction(SIGPIPE, &action, NULL);
 368
 369         pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
 370
 371         /* start daemon (i.e. the threads in the thread-pool) */
 372         charon->start(charon);
 373
 374         /* main thread goes to run loop */
 375         run();
 376
 377         unlink_pidfile();
 378         status = 0;
 379         charon->bus->remove_listener(charon->bus, &listener->listener);
 380         listener->destroy(listener);
 381         creds->destroy(creds);
 382
 383 deinit:
 384         libcharon_deinit();
 385         libhydra_deinit();
 386         library_deinit();
 387         tkm_deinit();
 388         return status;
 389 }