/mandos/trunk : revision 951

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* "browse_callback", and parts of "main".

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*

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* Everything else is

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*

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* This program is free software: you can redistribute it and/or

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* modify it under the terms of the GNU General Public License as

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* published by the Free Software Foundation, either version 3 of the

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* License, or (at your option) any later version.

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*

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* This program is distributed in the hope that it will be useful, but

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*

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* This file is part of Mandos.

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*

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* Mandos is free software: you can redistribute it and/or modify it

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* under the terms of the GNU General Public License as published by

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* the Free Software Foundation, either version 3 of the License, or

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* (at your option) any later version.

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*

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* Mandos is distributed in the hope that it will be useful, but

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* WITHOUT ANY WARRANTY; without even the implied warranty of

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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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* General Public License for more details.

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*

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* You should have received a copy of the GNU General Public License

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* along with this program. If not, see

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* <http://www.gnu.org/licenses/>.

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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

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*

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* Contact the authors at <mandos@recompile.se>.

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*/

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/* Needed by GPGME, specifically gpgme_data_seek() */

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif

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#endif /* not _LARGEFILE_SOURCE */

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

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#include <stdio.h> /* fprintf(), stderr, fwrite(),

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stdout, ferror(), remove() */

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stdout, ferror() */

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#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

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#include <stddef.h> /* NULL, size_t, ssize_t */

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#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

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strtof(), abort() */

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#include <stdbool.h> /* bool, false, true */

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#include <string.h> /* memset(), strcmp(), strlen(),

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strerror(), asprintf(), strcpy() */

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#include <string.h> /* strcmp(), strlen(), strerror(),

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asprintf(), strncpy(), strsignal()

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*/

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#include <sys/ioctl.h> /* ioctl */

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#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

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sockaddr_in6, PF_INET6,

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opendir(), DIR */

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#include <sys/stat.h> /* open(), S_ISREG */

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#include <sys/socket.h> /* socket(), struct sockaddr_in6,

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inet_pton(), connect() */

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#include <fcntl.h> /* open() */

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inet_pton(), connect(),

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getnameinfo() */

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#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */

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#include <dirent.h> /* opendir(), struct dirent, readdir()

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*/

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#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

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strtoimax() */

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#include <errno.h> /* perror(), errno,

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#include <errno.h> /* perror(), errno, EINTR, EINVAL,

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

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program_invocation_short_name */

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#include <time.h> /* nanosleep(), time(), sleep() */

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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

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*/

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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

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getuid(), getgid(), seteuid(),

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setgid(), pause(), _exit() */

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#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */

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setgid(), pause(), _exit(),

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unlinkat() */

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#include <arpa/inet.h> /* inet_pton(), htons() */

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#include <iso646.h> /* not, or, and */

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#include <argp.h> /* struct argp_option, error_t, struct

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argp_state, struct argp,

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

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#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

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EAI_SYSTEM, gai_strerror() */

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#ifdef __linux__

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#include <sys/klog.h> /* klogctl() */

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static const char sys_class_net[] = "/sys/class/net";

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char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

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int hookdir_fd = -1;

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uid_t uid = 65534;

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gid_t gid = 65534;

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perror(print_text);

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}

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__attribute__((format (gnu_printf, 2, 3)))

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__attribute__((format (gnu_printf, 2, 3), nonnull))

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int fprintf_plus(FILE *stream, const char *format, ...){

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va_list ap;

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va_start (ap, format);

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TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",

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program_invocation_short_name));

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return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

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return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

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}

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/*

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* bytes. "buffer_capacity" is how much is currently allocated,

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* "buffer_length" is how much is already used.

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*/

209

__attribute__((nonnull, warn_unused_result))

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size_t incbuffer(char **buffer, size_t buffer_length,

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211

size_t buffer_capacity){

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if(buffer_length + BUFFER_SIZE > buffer_capacity){

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*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

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if(buffer == NULL){

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char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

214

if(new_buf == NULL){

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int old_errno = errno;

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free(*buffer);

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errno = old_errno;

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*buffer = NULL;

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return 0;

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}

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*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

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223

}

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return buffer_capacity;

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}

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/* Add server to set of servers to retry periodically */

228

__attribute__((nonnull, warn_unused_result))

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bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,

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230

int af, server **current_server){

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int ret;

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.af = af };

223

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if(new_server->ip == NULL){

224

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perror_plus("strdup");

243

free(new_server);

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return false;

245

}

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ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

247

if(ret == -1){

248

perror_plus("clock_gettime");

249

#ifdef __GNUC__

250

#pragma GCC diagnostic push

251

#pragma GCC diagnostic ignored "-Wcast-qual"

252

#endif

253

free((char *)(new_server->ip));

254

#ifdef __GNUC__

255

#pragma GCC diagnostic pop

256

#endif

257

free(new_server);

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return false;

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259

}

227

260

/* Special case of first server */

229

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new_server->next = new_server;

230

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new_server->prev = new_server;

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*current_server = new_server;

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/* Place the new server last in the list */

233

265

} else {

266

/* Place the new server last in the list */

234

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new_server->next = *current_server;

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new_server->prev = (*current_server)->prev;

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new_server->prev->next = new_server;

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(*current_server)->prev = new_server;

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271

}

239

ret = clock_gettime(CLOCK_MONOTONIC, &(*current_server)->last_seen);

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

244

272

return true;

245

273

}

246

274

275

/* Set effective uid to 0, return errno */

276

__attribute__((warn_unused_result))

277

int raise_privileges(void){

278

int old_errno = errno;

279

int ret = 0;

280

if(seteuid(0) == -1){

281

ret = errno;

282

}

283

errno = old_errno;

284

return ret;

285

}

286

287

/* Set effective and real user ID to 0. Return errno. */

288

__attribute__((warn_unused_result))

289

int raise_privileges_permanently(void){

290

int old_errno = errno;

291

int ret = raise_privileges();

292

if(ret != 0){

293

errno = old_errno;

294

return ret;

295

}

296

if(setuid(0) == -1){

297

ret = errno;

298

}

299

errno = old_errno;

300

return ret;

301

}

302

303

/* Set effective user ID to unprivileged saved user ID */

304

__attribute__((warn_unused_result))

305

int lower_privileges(void){

306

int old_errno = errno;

307

int ret = 0;

308

if(seteuid(uid) == -1){

309

ret = errno;

310

}

311

errno = old_errno;

312

return ret;

313

}

314

315

/* Lower privileges permanently */

316

__attribute__((warn_unused_result))

317

int lower_privileges_permanently(void){

318

int old_errno = errno;

319

int ret = 0;

320

if(setuid(uid) == -1){

321

ret = errno;

322

}

323

errno = old_errno;

324

return ret;

325

}

326

247

327

/*

248

328

* Initialize GPGME.

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329

*/

250

static bool init_gpgme(const char *seckey, const char *pubkey,

251

const char *tempdir, mandos_context *mc){

330

__attribute__((nonnull, warn_unused_result))

331

static bool init_gpgme(const char * const seckey,

332

const char * const pubkey,

333

const char * const tempdir,

334

mandos_context *mc){

252

335

gpgme_error_t rc;

253

336

gpgme_engine_info_t engine_info;

254

337

255

338

/*

256

339

* Helper function to insert pub and seckey to the engine keyring.

257

340

*/

258

bool import_key(const char *filename){

341

bool import_key(const char * const filename){

259

342

int ret;

260

343

int fd;

261

344

gpgme_data_t pgp_data;

266

349

return false;

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350

}

268

351

352

/* Workaround for systems without a real-time clock; see also

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Debian bug #894495: <https://bugs.debian.org/894495> */

354

do {

355

{

356

time_t currtime = time(NULL);

357

if(currtime != (time_t)-1){

358

struct tm tm;

359

if(gmtime_r(&currtime, &tm) == NULL) {

360

perror_plus("gmtime_r");

361

break;

362

}

363

if(tm.tm_year != 70 or tm.tm_mon != 0){

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break;

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}

366

if(debug){

367

fprintf_plus(stderr, "System clock is January 1970");

368

}

369

} else {

370

if(debug){

371

fprintf_plus(stderr, "System clock is invalid");

372

}

373

}

374

}

375

struct stat keystat;

376

ret = fstat(fd, &keystat);

377

if(ret != 0){

378

perror_plus("fstat");

379

break;

380

}

381

ret = raise_privileges();

382

if(ret != 0){

383

errno = ret;

384

perror_plus("Failed to raise privileges");

385

break;

386

}

387

if(debug){

388

fprintf_plus(stderr,

389

"Setting system clock to key file mtime");

390

}

391

time_t keytime = keystat.st_mtim.tv_sec;

392

if(stime(&keytime) != 0){

393

perror_plus("stime");

394

}

395

ret = lower_privileges();

396

if(ret != 0){

397

errno = ret;

398

perror_plus("Failed to lower privileges");

399

}

400

} while(false);

401

269

402

rc = gpgme_data_new_from_fd(&pgp_data, fd);

270

403

if(rc != GPG_ERR_NO_ERROR){

271

404

fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

279

412

gpgme_strsource(rc), gpgme_strerror(rc));

280

413

return false;

281

414

}

415

{

416

gpgme_import_result_t import_result

417

= gpgme_op_import_result(mc->ctx);

418

if((import_result->imported < 1

419

or import_result->not_imported > 0)

420

and import_result->unchanged == 0){

421

fprintf_plus(stderr, "bad gpgme_op_import_results:\n");

422

fprintf_plus(stderr,

423

"The total number of considered keys: %d\n",

424

import_result->considered);

425

fprintf_plus(stderr,

426

"The number of keys without user ID: %d\n",

427

import_result->no_user_id);

428

fprintf_plus(stderr,

429

"The total number of imported keys: %d\n",

430

import_result->imported);

431

fprintf_plus(stderr, "The number of imported RSA keys: %d\n",

432

import_result->imported_rsa);

433

fprintf_plus(stderr, "The number of unchanged keys: %d\n",

434

import_result->unchanged);

435

fprintf_plus(stderr, "The number of new user IDs: %d\n",

436

import_result->new_user_ids);

437

fprintf_plus(stderr, "The number of new sub keys: %d\n",

438

import_result->new_sub_keys);

439

fprintf_plus(stderr, "The number of new signatures: %d\n",

440

import_result->new_signatures);

441

fprintf_plus(stderr, "The number of new revocations: %d\n",

442

import_result->new_revocations);

443

fprintf_plus(stderr,

444

"The total number of secret keys read: %d\n",

445

import_result->secret_read);

446

fprintf_plus(stderr,

447

"The number of imported secret keys: %d\n",

448

import_result->secret_imported);

449

fprintf_plus(stderr,

450

"The number of unchanged secret keys: %d\n",

451

import_result->secret_unchanged);

452

fprintf_plus(stderr, "The number of keys not imported: %d\n",

453

import_result->not_imported);

454

for(gpgme_import_status_t import_status

455

= import_result->imports;

456

import_status != NULL;

457

import_status = import_status->next){

458

fprintf_plus(stderr, "Import status for key: %s\n",

459

import_status->fpr);

460

if(import_status->result != GPG_ERR_NO_ERROR){

461

fprintf_plus(stderr, "Import result: %s: %s\n",

462

gpgme_strsource(import_status->result),

463

gpgme_strerror(import_status->result));

464

}

465

fprintf_plus(stderr, "Key status:\n");

466

fprintf_plus(stderr,

467

import_status->status & GPGME_IMPORT_NEW

468

? "The key was new.\n"

469

: "The key was not new.\n");

470

fprintf_plus(stderr,

471

import_status->status & GPGME_IMPORT_UID

472

? "The key contained new user IDs.\n"

473

: "The key did not contain new user IDs.\n");

474

fprintf_plus(stderr,

475

import_status->status & GPGME_IMPORT_SIG

476

? "The key contained new signatures.\n"

477

: "The key did not contain new signatures.\n");

478

fprintf_plus(stderr,

479

import_status->status & GPGME_IMPORT_SUBKEY

480

? "The key contained new sub keys.\n"

481

: "The key did not contain new sub keys.\n");

482

fprintf_plus(stderr,

483

import_status->status & GPGME_IMPORT_SECRET

484

? "The key contained a secret key.\n"

485

: "The key did not contain a secret key.\n");

486

}

487

return false;

488

}

489

}

282

490

283

ret = (int)TEMP_FAILURE_RETRY(close(fd));

491

ret = close(fd);

284

492

if(ret == -1){

285

493

perror_plus("close");

286

494

}

325

533

/* Create new GPGME "context" */

326

534

rc = gpgme_new(&(mc->ctx));

327

535

if(rc != GPG_ERR_NO_ERROR){

328

fprintf_plus(stderr, "Mandos plugin mandos-client: "

329

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

330

gpgme_strerror(rc));

536

fprintf_plus(stderr, "bad gpgme_new: %s: %s\n",

537

gpgme_strsource(rc), gpgme_strerror(rc));

331

538

return false;

332

539

}

333

540

342

549

* Decrypt OpenPGP data.

343

550

* Returns -1 on error

344

551

*/

552

__attribute__((nonnull, warn_unused_result))

345

553

static ssize_t pgp_packet_decrypt(const char *cryptotext,

346

554

size_t crypto_size,

347

555

char **plaintext,

368

576

/* Create new empty GPGME data buffer for the plaintext */

369

577

rc = gpgme_data_new(&dh_plain);

370

578

if(rc != GPG_ERR_NO_ERROR){

371

fprintf_plus(stderr, "Mandos plugin mandos-client: "

372

"bad gpgme_data_new: %s: %s\n",

579

fprintf_plus(stderr, "bad gpgme_data_new: %s: %s\n",

373

580

gpgme_strsource(rc), gpgme_strerror(rc));

374

581

gpgme_data_release(dh_crypto);

375

582

return -1;

388

595

if(result == NULL){

389

596

fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");

390

597

} else {

391

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

392

result->unsupported_algorithm);

393

fprintf_plus(stderr, "Wrong key usage: %u\n",

394

result->wrong_key_usage);

598

if(result->unsupported_algorithm != NULL) {

599

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

600

result->unsupported_algorithm);

601

}

602

fprintf_plus(stderr, "Wrong key usage: %s\n",

603

result->wrong_key_usage ? "Yes" : "No");

395

604

if(result->file_name != NULL){

396

605

fprintf_plus(stderr, "File name: %s\n", result->file_name);

397

606

}

398

gpgme_recipient_t recipient;

399

recipient = result->recipients;

400

while(recipient != NULL){

607

608

for(gpgme_recipient_t r = result->recipients; r != NULL;

609

r = r->next){

401

610

fprintf_plus(stderr, "Public key algorithm: %s\n",

402

gpgme_pubkey_algo_name

403

(recipient->pubkey_algo));

404

fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);

611

gpgme_pubkey_algo_name(r->pubkey_algo));

612

fprintf_plus(stderr, "Key ID: %s\n", r->keyid);

405

613

fprintf_plus(stderr, "Secret key available: %s\n",

406

recipient->status == GPG_ERR_NO_SECKEY

407

? "No" : "Yes");

408

recipient = recipient->next;

614

r->status == GPG_ERR_NO_SECKEY ? "No" : "Yes");

409

615

}

410

616

}

411

617

}

467

673

return plaintext_length;

468

674

}

469

675

470

static const char * safer_gnutls_strerror(int value){

676

__attribute__((warn_unused_result, const))

677

static const char *safe_string(const char *str){

678

if(str == NULL)

679

return "(unknown)";

680

return str;

681

}

682

683

__attribute__((warn_unused_result))

684

static const char *safer_gnutls_strerror(int value){

471

685

const char *ret = gnutls_strerror(value);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

686

return safe_string(ret);

475

687

}

476

688

477

689

/* GnuTLS log function callback */

690

__attribute__((nonnull))

478

691

static void debuggnutls(__attribute__((unused)) int level,

479

692

const char* string){

480

693

fprintf_plus(stderr, "GnuTLS: %s", string);

481

694

}

482

695

696

__attribute__((nonnull(1, 2, 4), warn_unused_result))

483

697

static int init_gnutls_global(const char *pubkeyfilename,

484

698

const char *seckeyfilename,

699

const char *dhparamsfilename,

485

700

mandos_context *mc){

486

701

int ret;

702

unsigned int uret;

487

703

488

704

if(debug){

489

705

fprintf_plus(stderr, "Initializing GnuTLS\n");

490

706

}

491

707

492

ret = gnutls_global_init();

493

if(ret != GNUTLS_E_SUCCESS){

494

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

495

safer_gnutls_strerror(ret));

496

return -1;

497

}

498

499

708

if(debug){

500

709

/* "Use a log level over 10 to enable all debugging options."

501

710

* - GnuTLS manual

509

718

if(ret != GNUTLS_E_SUCCESS){

510

719

fprintf_plus(stderr, "GnuTLS memory error: %s\n",

511

720

safer_gnutls_strerror(ret));

512

gnutls_global_deinit();

513

721

return -1;

514

722

}

515

723

540

748

safer_gnutls_strerror(ret));

541

749

goto globalfail;

542

750

}

543

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

544

if(ret != GNUTLS_E_SUCCESS){

545

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

546

safer_gnutls_strerror(ret));

547

goto globalfail;

548

}

549

751

/* If a Diffie-Hellman parameters file was given, try to use it */

752

if(dhparamsfilename != NULL){

753

gnutls_datum_t params = { .data = NULL, .size = 0 };

754

do {

755

int dhpfile = open(dhparamsfilename, O_RDONLY);

756

if(dhpfile == -1){

757

perror_plus("open");

758

dhparamsfilename = NULL;

759

break;

760

}

761

size_t params_capacity = 0;

762

while(true){

763

params_capacity = incbuffer((char **)&params.data,

764

(size_t)params.size,

765

(size_t)params_capacity);

766

if(params_capacity == 0){

767

perror_plus("incbuffer");

768

free(params.data);

769

params.data = NULL;

770

dhparamsfilename = NULL;

771

break;

772

}

773

ssize_t bytes_read = read(dhpfile,

774

params.data + params.size,

775

BUFFER_SIZE);

776

/* EOF */

777

if(bytes_read == 0){

778

break;

779

}

780

/* check bytes_read for failure */

781

if(bytes_read < 0){

782

perror_plus("read");

783

free(params.data);

784

params.data = NULL;

785

dhparamsfilename = NULL;

786

break;

787

}

788

params.size += (unsigned int)bytes_read;

789

}

790

ret = close(dhpfile);

791

if(ret == -1){

792

perror_plus("close");

793

}

794

if(params.data == NULL){

795

dhparamsfilename = NULL;

796

}

797

if(dhparamsfilename == NULL){

798

break;

799

}

800

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

801

GNUTLS_X509_FMT_PEM);

802

if(ret != GNUTLS_E_SUCCESS){

803

fprintf_plus(stderr, "Failed to parse DH parameters in file"

804

" \"%s\": %s\n", dhparamsfilename,

805

safer_gnutls_strerror(ret));

806

dhparamsfilename = NULL;

807

}

808

free(params.data);

809

} while(false);

810

}

811

if(dhparamsfilename == NULL){

812

if(mc->dh_bits == 0){

813

/* Find out the optimal number of DH bits */

814

/* Try to read the private key file */

815

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

816

do {

817

int secfile = open(seckeyfilename, O_RDONLY);

818

if(secfile == -1){

819

perror_plus("open");

820

break;

821

}

822

size_t buffer_capacity = 0;

823

while(true){

824

buffer_capacity = incbuffer((char **)&buffer.data,

825

(size_t)buffer.size,

826

(size_t)buffer_capacity);

827

if(buffer_capacity == 0){

828

perror_plus("incbuffer");

829

free(buffer.data);

830

buffer.data = NULL;

831

break;

832

}

833

ssize_t bytes_read = read(secfile,

834

buffer.data + buffer.size,

835

BUFFER_SIZE);

836

/* EOF */

837

if(bytes_read == 0){

838

break;

839

}

840

/* check bytes_read for failure */

841

if(bytes_read < 0){

842

perror_plus("read");

843

free(buffer.data);

844

buffer.data = NULL;

845

break;

846

}

847

buffer.size += (unsigned int)bytes_read;

848

}

849

close(secfile);

850

} while(false);

851

/* If successful, use buffer to parse private key */

852

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

853

if(buffer.data != NULL){

854

{

855

gnutls_openpgp_privkey_t privkey = NULL;

856

ret = gnutls_openpgp_privkey_init(&privkey);

857

if(ret != GNUTLS_E_SUCCESS){

858

fprintf_plus(stderr, "Error initializing OpenPGP key"

859

" structure: %s",

860

safer_gnutls_strerror(ret));

861

free(buffer.data);

862

buffer.data = NULL;

863

} else {

864

ret = gnutls_openpgp_privkey_import

865

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

866

if(ret != GNUTLS_E_SUCCESS){

867

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

868

safer_gnutls_strerror(ret));

869

privkey = NULL;

870

}

871

free(buffer.data);

872

buffer.data = NULL;

873

if(privkey != NULL){

874

/* Use private key to suggest an appropriate

875

sec_param */

876

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

877

gnutls_openpgp_privkey_deinit(privkey);

878

if(debug){

879

fprintf_plus(stderr, "This OpenPGP key implies using"

880

" a GnuTLS security parameter \"%s\".\n",

881

safe_string(gnutls_sec_param_get_name

882

(sec_param)));

883

}

884

}

885

}

886

}

887

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

888

/* Err on the side of caution */

889

sec_param = GNUTLS_SEC_PARAM_ULTRA;

890

if(debug){

891

fprintf_plus(stderr, "Falling back to security parameter"

892

" \"%s\"\n",

893

safe_string(gnutls_sec_param_get_name

894

(sec_param)));

895

}

896

}

897

}

898

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

899

if(uret != 0){

900

mc->dh_bits = uret;

901

if(debug){

902

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

903

" implies %u DH bits; using that.\n",

904

safe_string(gnutls_sec_param_get_name

905

(sec_param)),

906

mc->dh_bits);

907

}

908

} else {

909

fprintf_plus(stderr, "Failed to get implied number of DH"

910

" bits for security parameter \"%s\"): %s\n",

911

safe_string(gnutls_sec_param_get_name

912

(sec_param)),

913

safer_gnutls_strerror(ret));

914

goto globalfail;

915

}

916

} else if(debug){

917

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

918

mc->dh_bits);

919

}

920

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

921

if(ret != GNUTLS_E_SUCCESS){

922

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

923

" bits): %s\n", mc->dh_bits,

924

safer_gnutls_strerror(ret));

925

goto globalfail;

926

}

927

}

550

928

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

551

929

552

930

return 0;

554

932

globalfail:

555

933

556

934

gnutls_certificate_free_credentials(mc->cred);

557

gnutls_global_deinit();

558

935

gnutls_dh_params_deinit(mc->dh_params);

559

936

return -1;

560

937

}

561

938

939

__attribute__((nonnull, warn_unused_result))

562

940

static int init_gnutls_session(gnutls_session_t *session,

563

941

mandos_context *mc){

564

942

int ret;

611

989

/* ignore client certificate if any. */

612

990

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

991

614

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

616

992

return 0;

617

993

}

618

994

620

996

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

621

997

__attribute__((unused)) const char *txt){}

622

998

999

/* Helper function to add_local_route() and delete_local_route() */

1000

__attribute__((nonnull, warn_unused_result))

1001

static bool add_delete_local_route(const bool add,

1002

const char *address,

1003

AvahiIfIndex if_index){

1004

int ret;

1005

char helper[] = "mandos-client-iprouteadddel";

1006

char add_arg[] = "add";

1007

char delete_arg[] = "delete";

1008

char debug_flag[] = "--debug";

1009

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1010

if(pluginhelperdir == NULL){

1011

if(debug){

1012

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1013

" variable not set; cannot run helper\n");

1014

}

1015

return false;

1016

}

1017

1018

char interface[IF_NAMESIZE];

1019

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1020

perror_plus("if_indextoname");

1021

return false;

1022

}

1023

1024

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1025

if(devnull == -1){

1026

perror_plus("open(\"/dev/null\", O_RDONLY)");

1027

return false;

1028

}

1029

pid_t pid = fork();

1030

if(pid == 0){

1031

/* Child */

1032

/* Raise privileges */

1033

errno = raise_privileges_permanently();

1034

if(errno != 0){

1035

perror_plus("Failed to raise privileges");

1036

/* _exit(EX_NOPERM); */

1037

} else {

1038

/* Set group */

1039

errno = 0;

1040

ret = setgid(0);

1041

if(ret == -1){

1042

perror_plus("setgid");

1043

_exit(EX_NOPERM);

1044

}

1045

/* Reset supplementary groups */

1046

errno = 0;

1047

ret = setgroups(0, NULL);

1048

if(ret == -1){

1049

perror_plus("setgroups");

1050

_exit(EX_NOPERM);

1051

}

1052

}

1053

ret = dup2(devnull, STDIN_FILENO);

1054

if(ret == -1){

1055

perror_plus("dup2(devnull, STDIN_FILENO)");

1056

_exit(EX_OSERR);

1057

}

1058

ret = close(devnull);

1059

if(ret == -1){

1060

perror_plus("close");

1061

_exit(EX_OSERR);

1062

}

1063

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1064

if(ret == -1){

1065

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1066

_exit(EX_OSERR);

1067

}

1068

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

1069

O_RDONLY

1070

| O_DIRECTORY

1071

| O_PATH

1072

| O_CLOEXEC));

1073

if(helperdir_fd == -1){

1074

perror_plus("open");

1075

_exit(EX_UNAVAILABLE);

1076

}

1077

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

1078

helper, O_RDONLY));

1079

if(helper_fd == -1){

1080

perror_plus("openat");

1081

close(helperdir_fd);

1082

_exit(EX_UNAVAILABLE);

1083

}

1084

close(helperdir_fd);

1085

#ifdef __GNUC__

1086

#pragma GCC diagnostic push

1087

#pragma GCC diagnostic ignored "-Wcast-qual"

1088

#endif

1089

if(fexecve(helper_fd, (char *const [])

1090

{ helper, add ? add_arg : delete_arg, (char *)address,

1091

interface, debug ? debug_flag : NULL, NULL },

1092

environ) == -1){

1093

#ifdef __GNUC__

1094

#pragma GCC diagnostic pop

1095

#endif

1096

perror_plus("fexecve");

1097

_exit(EXIT_FAILURE);

1098

}

1099

}

1100

if(pid == -1){

1101

perror_plus("fork");

1102

return false;

1103

}

1104

int status;

1105

pid_t pret = -1;

1106

errno = 0;

1107

do {

1108

pret = waitpid(pid, &status, 0);

1109

if(pret == -1 and errno == EINTR and quit_now){

1110

int errno_raising = 0;

1111

if((errno = raise_privileges()) != 0){

1112

errno_raising = errno;

1113

perror_plus("Failed to raise privileges in order to"

1114

" kill helper program");

1115

}

1116

if(kill(pid, SIGTERM) == -1){

1117

perror_plus("kill");

1118

}

1119

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

1120

perror_plus("Failed to lower privileges after killing"

1121

" helper program");

1122

}

1123

return false;

1124

}

1125

} while(pret == -1 and errno == EINTR);

1126

if(pret == -1){

1127

perror_plus("waitpid");

1128

return false;

1129

}

1130

if(WIFEXITED(status)){

1131

if(WEXITSTATUS(status) != 0){

1132

fprintf_plus(stderr, "Error: iprouteadddel exited"

1133

" with status %d\n", WEXITSTATUS(status));

1134

return false;

1135

}

1136

return true;

1137

}

1138

if(WIFSIGNALED(status)){

1139

fprintf_plus(stderr, "Error: iprouteadddel died by"

1140

" signal %d\n", WTERMSIG(status));

1141

return false;

1142

}

1143

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1144

return false;

1145

}

1146

1147

__attribute__((nonnull, warn_unused_result))

1148

static bool add_local_route(const char *address,

1149

AvahiIfIndex if_index){

1150

if(debug){

1151

fprintf_plus(stderr, "Adding route to %s\n", address);

1152

}

1153

return add_delete_local_route(true, address, if_index);

1154

}

1155

1156

__attribute__((nonnull, warn_unused_result))

1157

static bool delete_local_route(const char *address,

1158

AvahiIfIndex if_index){

1159

if(debug){

1160

fprintf_plus(stderr, "Removing route to %s\n", address);

1161

}

1162

return add_delete_local_route(false, address, if_index);

1163

}

1164

623

1165

/* Called when a Mandos server is found */

1166

__attribute__((nonnull, warn_unused_result))

624

1167

static int start_mandos_communication(const char *ip, in_port_t port,

625

1168

AvahiIfIndex if_index,

626

1169

int af, mandos_context *mc){

627

1170

int ret, tcp_sd = -1;

628

1171

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1172

struct sockaddr_storage to;

633

1173

char *buffer = NULL;

634

1174

char *decrypted_buffer = NULL;

635

1175

size_t buffer_length = 0;

638

1178

int retval = -1;

639

1179

gnutls_session_t session;

640

1180

int pf; /* Protocol family */

1181

bool route_added = false;

641

1182

642

1183

errno = 0;

643

1184

659

1200

return -1;

660

1201

}

661

1202

1203

/* If the interface is specified and we have a list of interfaces */

1204

if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){

1205

/* Check if the interface is one of the interfaces we are using */

1206

bool match = false;

1207

{

1208

char *interface = NULL;

1209

while((interface = argz_next(mc->interfaces,

1210

mc->interfaces_size,

1211

interface))){

1212

if(if_nametoindex(interface) == (unsigned int)if_index){

1213

match = true;

1214

break;

1215

}

1216

}

1217

}

1218

if(not match){

1219

/* This interface does not match any in the list, so we don't

1220

connect to the server */

1221

if(debug){

1222

char interface[IF_NAMESIZE];

1223

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1224

perror_plus("if_indextoname");

1225

} else {

1226

fprintf_plus(stderr, "Skipping server on non-used interface"

1227

" \"%s\"\n",

1228

if_indextoname((unsigned int)if_index,

1229

interface));

1230

}

1231

}

1232

return -1;

1233

}

1234

}

1235

662

1236

ret = init_gnutls_session(&session, mc);

663

1237

if(ret != 0){

664

1238

return -1;

669

1243

PRIuMAX "\n", ip, (uintmax_t)port);

670

1244

}

671

1245

672

tcp_sd = socket(pf, SOCK_STREAM, 0);

1246

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

673

1247

if(tcp_sd < 0){

674

1248

int e = errno;

675

1249

perror_plus("socket");

682

1256

goto mandos_end;

683

1257

}

684

1258

685

memset(&to, 0, sizeof(to));

686

1259

if(af == AF_INET6){

687

to.in6.sin6_family = (sa_family_t)af;

688

ret = inet_pton(af, ip, &to.in6.sin6_addr);

1260

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1261

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1262

ret = inet_pton(af, ip, &to6->sin6_addr);

689

1263

} else { /* IPv4 */

690

to.in.sin_family = (sa_family_t)af;

691

ret = inet_pton(af, ip, &to.in.sin_addr);

1264

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1265

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1266

ret = inet_pton(af, ip, &to4->sin_addr);

692

1267

}

693

1268

if(ret < 0 ){

694

1269

int e = errno;

703

1278

goto mandos_end;

704

1279

}

705

1280

if(af == AF_INET6){

706

to.in6.sin6_port = htons(port);

707

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

708

(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and

709

-Wunreachable-code*/

1281

((struct sockaddr_in6 *)&to)->sin6_port = htons(port);

1282

if(IN6_IS_ADDR_LINKLOCAL

1283

(&((struct sockaddr_in6 *)&to)->sin6_addr)){

710

1284

if(if_index == AVAHI_IF_UNSPEC){

711

1285

fprintf_plus(stderr, "An IPv6 link-local address is"

712

1286

" incomplete without a network interface\n");

714

1288

goto mandos_end;

715

1289

}

716

1290

/* Set the network interface number as scope */

717

to.in6.sin6_scope_id = (uint32_t)if_index;

1291

((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;

718

1292

}

719

1293

} else {

720

to.in.sin_port = htons(port); /* Spurious warnings from

721

-Wconversion and

722

-Wunreachable-code */

1294

((struct sockaddr_in *)&to)->sin_port = htons(port);

723

1295

}

724

1296

725

1297

if(quit_now){

742

1314

}

743

1315

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

744

1316

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

745

const char *pcret;

746

if(af == AF_INET6){

747

pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,

748

sizeof(addrstr));

749

} else {

750

pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,

751

sizeof(addrstr));

752

}

753

if(pcret == NULL){

754

perror_plus("inet_ntop");

755

} else {

756

if(strcmp(addrstr, ip) != 0){

757

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

758

}

759

}

760

}

761

762

if(quit_now){

763

errno = EINTR;

764

goto mandos_end;

765

}

766

767

if(af == AF_INET6){

768

ret = connect(tcp_sd, &to.in6, sizeof(to));

769

} else {

770

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

771

}

772

if(ret < 0){

773

if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

774

int e = errno;

775

perror_plus("connect");

776

errno = e;

777

}

778

goto mandos_end;

779

}

780

781

if(quit_now){

782

errno = EINTR;

783

goto mandos_end;

1317

if(af == AF_INET6){

1318

ret = getnameinfo((struct sockaddr *)&to,

1319

sizeof(struct sockaddr_in6),

1320

addrstr, sizeof(addrstr), NULL, 0,

1321

NI_NUMERICHOST);

1322

} else {

1323

ret = getnameinfo((struct sockaddr *)&to,

1324

sizeof(struct sockaddr_in),

1325

addrstr, sizeof(addrstr), NULL, 0,

1326

NI_NUMERICHOST);

1327

}

1328

if(ret == EAI_SYSTEM){

1329

perror_plus("getnameinfo");

1330

} else if(ret != 0) {

1331

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

1332

} else if(strcmp(addrstr, ip) != 0){

1333

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

1334

}

1335

}

1336

1337

if(quit_now){

1338

errno = EINTR;

1339

goto mandos_end;

1340

}

1341

1342

while(true){

1343

if(af == AF_INET6){

1344

ret = connect(tcp_sd, (struct sockaddr *)&to,

1345

sizeof(struct sockaddr_in6));

1346

} else {

1347

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1348

sizeof(struct sockaddr_in));

1349

}

1350

if(ret < 0){

1351

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1352

and if_index != AVAHI_IF_UNSPEC

1353

and connect_to == NULL

1354

and not route_added and

1355

((af == AF_INET6 and not

1356

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1357

&to)->sin6_addr)))

1358

or (af == AF_INET and

1359

/* Not a a IPv4LL address */

1360

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1361

& 0xFFFF0000L) != 0xA9FE0000L))){

1362

/* Work around Avahi bug - Avahi does not announce link-local

1363

addresses if it has a global address, so local hosts with

1364

*only* a link-local address (e.g. Mandos clients) cannot

1365

connect to a Mandos server announced by Avahi on a server

1366

host with a global address. Work around this by retrying

1367

with an explicit route added with the server's address.

1368

1369

Avahi bug reference:

1370

https://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1371

https://bugs.debian.org/587961

1372

*/

1373

if(debug){

1374

fprintf_plus(stderr, "Mandos server unreachable, trying"

1375

" direct route\n");

1376

}

1377

int e = errno;

1378

route_added = add_local_route(ip, if_index);

1379

if(route_added){

1380

continue;

1381

}

1382

errno = e;

1383

}

1384

if(errno != ECONNREFUSED or debug){

1385

int e = errno;

1386

perror_plus("connect");

1387

errno = e;

1388

}

1389

goto mandos_end;

1390

}

1391

1392

if(quit_now){

1393

errno = EINTR;

1394

goto mandos_end;

1395

}

1396

break;

784

1397

}

785

1398

786

1399

const char *out = mandos_protocol_version;

940

1553

&decrypted_buffer, mc);

941

1554

if(decrypted_buffer_size >= 0){

942

1555

1556

clearerr(stdout);

943

1557

written = 0;

944

1558

while(written < (size_t) decrypted_buffer_size){

945

1559

if(quit_now){

961

1575

}

962

1576

written += (size_t)ret;

963

1577

}

1578

ret = fflush(stdout);

1579

if(ret != 0){

1580

int e = errno;

1581

if(debug){

1582

fprintf_plus(stderr, "Error writing encrypted data: %s\n",

1583

strerror(errno));

1584

}

1585

errno = e;

1586

goto mandos_end;

1587

}

964

1588

retval = 0;

965

1589

}

966

1590

}

969

1593

970

1594

mandos_end:

971

1595

{

1596

if(route_added){

1597

if(not delete_local_route(ip, if_index)){

1598

fprintf_plus(stderr, "Failed to delete local route to %s on"

1599

" interface %d", ip, if_index);

1600

}

1601

}

972

1602

int e = errno;

973

1603

free(decrypted_buffer);

974

1604

free(buffer);

975

1605

if(tcp_sd >= 0){

976

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

1606

ret = close(tcp_sd);

977

1607

}

978

1608

if(ret == -1){

979

1609

if(e == 0){

1004

1634

AVAHI_GCC_UNUSED AvahiStringList *txt,

1005

1635

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1006

1636

flags,

1007

void* mc){

1637

void *mc){

1008

1638

if(r == NULL){

1009

1639

return;

1010

1640

}

1013

1643

timed out */

1014

1644

1015

1645

if(quit_now){

1646

avahi_s_service_resolver_free(r);

1016

1647

return;

1017

1648

}

1018

1649

1063

1694

const char *domain,

1064

1695

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1065

1696

flags,

1066

void* mc){

1697

void *mc){

1067

1698

if(b == NULL){

1068

1699

return;

1069

1700

}

1129

1760

errno = old_errno;

1130

1761

}

1131

1762

1763

__attribute__((nonnull, warn_unused_result))

1132

1764

bool get_flags(const char *ifname, struct ifreq *ifr){

1133

1765

int ret;

1134

error_t ret_errno;

1766

int old_errno;

1135

1767

1136

1768

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1137

1769

if(s < 0){

1138

ret_errno = errno;

1770

old_errno = errno;

1139

1771

perror_plus("socket");

1140

errno = ret_errno;

1772

errno = old_errno;

1141

1773

return false;

1142

1774

}

1143

strcpy(ifr->ifr_name, ifname);

1775

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1776

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1144

1777

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1145

1778

if(ret == -1){

1146

1779

if(debug){

1147

ret_errno = errno;

1780

old_errno = errno;

1148

1781

perror_plus("ioctl SIOCGIFFLAGS");

1149

errno = ret_errno;

1782

errno = old_errno;

1783

}

1784

if((close(s) == -1) and debug){

1785

old_errno = errno;

1786

perror_plus("close");

1787

errno = old_errno;

1150

1788

}

1151

1789

return false;

1152

1790

}

1791

if((close(s) == -1) and debug){

1792

old_errno = errno;

1793

perror_plus("close");

1794

errno = old_errno;

1795

}

1153

1796

return true;

1154

1797

}

1155

1798

1799

__attribute__((nonnull, warn_unused_result))

1156

1800

bool good_flags(const char *ifname, const struct ifreq *ifr){

1157

1801

1158

1802

/* Reject the loopback device */

1200

1844

* corresponds to an acceptable network device.

1201

1845

* (This function is passed to scandir(3) as a filter function.)

1202

1846

*/

1847

__attribute__((nonnull, warn_unused_result))

1203

1848

int good_interface(const struct dirent *if_entry){

1204

1849

if(if_entry->d_name[0] == '.'){

1205

1850

return 0;

1223

1868

/*

1224

1869

* This function determines if a network interface is up.

1225

1870

*/

1871

__attribute__((nonnull, warn_unused_result))

1226

1872

bool interface_is_up(const char *interface){

1227

1873

struct ifreq ifr;

1228

1874

if(not get_flags(interface, &ifr)){

1239

1885

/*

1240

1886

* This function determines if a network interface is running

1241

1887

*/

1888

__attribute__((nonnull, warn_unused_result))

1242

1889

bool interface_is_running(const char *interface){

1243

1890

struct ifreq ifr;

1244

1891

if(not get_flags(interface, &ifr)){

1252

1899

return (bool)(ifr.ifr_flags & IFF_RUNNING);

1253

1900

}

1254

1901

1902

__attribute__((nonnull, pure, warn_unused_result))

1255

1903

int notdotentries(const struct dirent *direntry){

1256

1904

/* Skip "." and ".." */

1257

1905

if(direntry->d_name[0] == '.'

1264

1912

}

1265

1913

1266

1914

/* Is this directory entry a runnable program? */

1915

__attribute__((nonnull, warn_unused_result))

1267

1916

int runnable_hook(const struct dirent *direntry){

1268

1917

int ret;

1269

1918

size_t sret;

1277

1926

sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

1278

1927

"abcdefghijklmnopqrstuvwxyz"

1279

1928

"0123456789"

1280

"_-");

1929

"_.-");

1281

1930

if((direntry->d_name)[sret] != '\0'){

1282

1931

/* Contains non-allowed characters */

1283

1932

if(debug){

1287

1936

return 0;

1288

1937

}

1289

1938

1290

char *fullname = NULL;

1291

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1292

if(ret < 0){

1293

perror_plus("asprintf");

1294

return 0;

1295

}

1296

1297

ret = stat(fullname, &st);

1939

ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);

1298

1940

if(ret == -1){

1299

1941

if(debug){

1300

1942

perror_plus("Could not stat hook");

1324

1966

return 1;

1325

1967

}

1326

1968

1969

__attribute__((nonnull, warn_unused_result))

1327

1970

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1328

1971

mandos_context *mc){

1329

1972

int ret;

1333

1976

1334

1977

while(true){

1335

1978

if(mc->current_server == NULL){

1336

if (debug){

1979

if(debug){

1337

1980

fprintf_plus(stderr, "Wait until first server is found."

1338

1981

" No timeout!\n");

1339

1982

}

1340

1983

ret = avahi_simple_poll_iterate(s, -1);

1341

1984

} else {

1342

if (debug){

1985

if(debug){

1343

1986

fprintf_plus(stderr, "Check current_server if we should run"

1344

1987

" it, or wait\n");

1345

1988

}

1362

2005

- ((intmax_t)waited_time.tv_sec * 1000))

1363

2006

- ((intmax_t)waited_time.tv_nsec / 1000000));

1364

2007

1365

if (debug){

2008

if(debug){

1366

2009

fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",

1367

2010

block_time);

1368

2011

}

1390

2033

ret = avahi_simple_poll_iterate(s, (int)block_time);

1391

2034

}

1392

2035

if(ret != 0){

1393

if (ret > 0 or errno != EINTR){

2036

if(ret > 0 or errno != EINTR){

1394

2037

return (ret != 1) ? ret : 0;

1395

2038

}

1396

2039

}

1397

2040

}

1398

2041

}

1399

2042

1400

/* Set effective uid to 0, return errno */

1401

error_t raise_privileges(void){

1402

error_t old_errno = errno;

1403

error_t ret_errno = 0;

1404

if(seteuid(0) == -1){

1405

ret_errno = errno;

1406

perror_plus("seteuid");

1407

}

1408

errno = old_errno;

1409

return ret_errno;

1410

}

1411

1412

/* Set effective and real user ID to 0. Return errno. */

1413

error_t raise_privileges_permanently(void){

1414

error_t old_errno = errno;

1415

error_t ret_errno = raise_privileges();

1416

if(ret_errno != 0){

1417

errno = old_errno;

1418

return ret_errno;

1419

}

1420

if(setuid(0) == -1){

1421

ret_errno = errno;

1422

perror_plus("seteuid");

1423

}

1424

errno = old_errno;

1425

return ret_errno;

1426

}

1427

1428

/* Set effective user ID to unprivileged saved user ID */

1429

error_t lower_privileges(void){

1430

error_t old_errno = errno;

1431

error_t ret_errno = 0;

1432

if(seteuid(uid) == -1){

1433

ret_errno = errno;

1434

perror_plus("seteuid");

1435

}

1436

errno = old_errno;

1437

return ret_errno;

1438

}

1439

1440

/* Lower privileges permanently */

1441

error_t lower_privileges_permanently(void){

1442

error_t old_errno = errno;

1443

error_t ret_errno = 0;

1444

if(setuid(uid) == -1){

1445

ret_errno = errno;

1446

perror_plus("setuid");

1447

}

1448

errno = old_errno;

1449

return ret_errno;

1450

}

1451

1452

bool run_network_hooks(const char *mode, const char *interface,

2043

__attribute__((nonnull))

2044

void run_network_hooks(const char *mode, const char *interface,

1453

2045

const float delay){

1454

struct dirent **direntries;

2046

struct dirent **direntries = NULL;

2047

if(hookdir_fd == -1){

2048

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2049

| O_CLOEXEC);

2050

if(hookdir_fd == -1){

2051

if(errno == ENOENT){

2052

if(debug){

2053

fprintf_plus(stderr, "Network hook directory \"%s\" not"

2054

" found\n", hookdir);

2055

}

2056

} else {

2057

perror_plus("open");

2058

}

2059

return;

2060

}

2061

}

2062

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

2063

if(devnull == -1){

2064

perror_plus("open(\"/dev/null\", O_RDONLY)");

2065

return;

2066

}

2067

int numhooks = scandirat(hookdir_fd, ".", &direntries,

2068

runnable_hook, alphasort);

2069

if(numhooks == -1){

2070

perror_plus("scandir");

2071

close(devnull);

2072

return;

2073

}

1455

2074

struct dirent *direntry;

1456

2075

int ret;

1457

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1458

alphasort);

1459

if(numhooks == -1){

1460

if(errno == ENOENT){

1461

if(debug){

1462

fprintf_plus(stderr, "Network hook directory \"%s\" not"

1463

" found\n", hookdir);

1464

}

1465

} else {

1466

perror_plus("scandir");

2076

for(int i = 0; i < numhooks; i++){

2077

direntry = direntries[i];

2078

if(debug){

2079

fprintf_plus(stderr, "Running network hook \"%s\"\n",

2080

direntry->d_name);

1467

2081

}

1468

} else {

1469

int devnull = open("/dev/null", O_RDONLY);

1470

for(int i = 0; i < numhooks; i++){

1471

direntry = direntries[i];

1472

char *fullname = NULL;

1473

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1474

if(ret < 0){

2082

pid_t hook_pid = fork();

2083

if(hook_pid == 0){

2084

/* Child */

2085

/* Raise privileges */

2086

errno = raise_privileges_permanently();

2087

if(errno != 0){

2088

perror_plus("Failed to raise privileges");

2089

_exit(EX_NOPERM);

2090

}

2091

/* Set group */

2092

errno = 0;

2093

ret = setgid(0);

2094

if(ret == -1){

2095

perror_plus("setgid");

2096

_exit(EX_NOPERM);

2097

}

2098

/* Reset supplementary groups */

2099

errno = 0;

2100

ret = setgroups(0, NULL);

2101

if(ret == -1){

2102

perror_plus("setgroups");

2103

_exit(EX_NOPERM);

2104

}

2105

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

2106

if(ret == -1){

2107

perror_plus("setenv");

2108

_exit(EX_OSERR);

2109

}

2110

ret = setenv("DEVICE", interface, 1);

2111

if(ret == -1){

2112

perror_plus("setenv");

2113

_exit(EX_OSERR);

2114

}

2115

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

2116

if(ret == -1){

2117

perror_plus("setenv");

2118

_exit(EX_OSERR);

2119

}

2120

ret = setenv("MODE", mode, 1);

2121

if(ret == -1){

2122

perror_plus("setenv");

2123

_exit(EX_OSERR);

2124

}

2125

char *delaystring;

2126

ret = asprintf(&delaystring, "%f", (double)delay);

2127

if(ret == -1){

1475

2128

perror_plus("asprintf");

1476

continue;

1477

}

1478

if(debug){

1479

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1480

direntry->d_name);

1481

}

1482

pid_t hook_pid = fork();

1483

if(hook_pid == 0){

1484

/* Child */

1485

/* Raise privileges */

1486

raise_privileges_permanently();

1487

/* Set group */

1488

errno = 0;

1489

ret = setgid(0);

1490

if(ret == -1){

1491

perror_plus("setgid");

1492

}

1493

/* Reset supplementary groups */

1494

errno = 0;

1495

ret = setgroups(0, NULL);

1496

if(ret == -1){

1497

perror_plus("setgroups");

1498

}

1499

dup2(devnull, STDIN_FILENO);

1500

close(devnull);

1501

dup2(STDERR_FILENO, STDOUT_FILENO);

1502

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1503

if(ret == -1){

1504

perror_plus("setenv");

1505

_exit(EX_OSERR);

1506

}

1507

ret = setenv("DEVICE", interface, 1);

1508

if(ret == -1){

1509

perror_plus("setenv");

1510

_exit(EX_OSERR);

1511

}

1512

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

1513

if(ret == -1){

1514

perror_plus("setenv");

1515

_exit(EX_OSERR);

1516

}

1517

ret = setenv("MODE", mode, 1);

1518

if(ret == -1){

1519

perror_plus("setenv");

1520

_exit(EX_OSERR);

1521

}

1522

char *delaystring;

1523

ret = asprintf(&delaystring, "%f", delay);

1524

if(ret == -1){

1525

perror_plus("asprintf");

1526

_exit(EX_OSERR);

1527

}

1528

ret = setenv("DELAY", delaystring, 1);

1529

if(ret == -1){

1530

free(delaystring);

1531

perror_plus("setenv");

1532

_exit(EX_OSERR);

1533

}

2129

_exit(EX_OSERR);

2130

}

2131

ret = setenv("DELAY", delaystring, 1);

2132

if(ret == -1){

1534

2133

free(delaystring);

1535

if(connect_to != NULL){

1536

ret = setenv("CONNECT", connect_to, 1);

1537

if(ret == -1){

1538

perror_plus("setenv");

1539

_exit(EX_OSERR);

1540

}

1541

}

1542

if(execl(fullname, direntry->d_name, mode, NULL) == -1){

1543

perror_plus("execl");

1544

_exit(EXIT_FAILURE);

1545

}

2134

perror_plus("setenv");

2135

_exit(EX_OSERR);

2136

}

2137

free(delaystring);

2138

if(connect_to != NULL){

2139

ret = setenv("CONNECT", connect_to, 1);

2140

if(ret == -1){

2141

perror_plus("setenv");

2142

_exit(EX_OSERR);

2143

}

2144

}

2145

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2146

direntry->d_name,

2147

O_RDONLY));

2148

if(hook_fd == -1){

2149

perror_plus("openat");

2150

_exit(EXIT_FAILURE);

2151

}

2152

if(close(hookdir_fd) == -1){

2153

perror_plus("close");

2154

_exit(EXIT_FAILURE);

2155

}

2156

ret = dup2(devnull, STDIN_FILENO);

2157

if(ret == -1){

2158

perror_plus("dup2(devnull, STDIN_FILENO)");

2159

_exit(EX_OSERR);

2160

}

2161

ret = close(devnull);

2162

if(ret == -1){

2163

perror_plus("close");

2164

_exit(EX_OSERR);

2165

}

2166

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2167

if(ret == -1){

2168

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2169

_exit(EX_OSERR);

2170

}

2171

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

2172

environ) == -1){

2173

perror_plus("fexecve");

2174

_exit(EXIT_FAILURE);

2175

}

2176

} else {

2177

if(hook_pid == -1){

2178

perror_plus("fork");

2179

free(direntry);

2180

continue;

2181

}

2182

int status;

2183

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

2184

perror_plus("waitpid");

2185

free(direntry);

2186

continue;

2187

}

2188

if(WIFEXITED(status)){

2189

if(WEXITSTATUS(status) != 0){

2190

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

2191

" with status %d\n", direntry->d_name,

2192

WEXITSTATUS(status));

2193

free(direntry);

2194

continue;

2195

}

2196

} else if(WIFSIGNALED(status)){

2197

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

2198

" signal %d\n", direntry->d_name,

2199

WTERMSIG(status));

2200

free(direntry);

2201

continue;

1546

2202

} else {

1547

int status;

1548

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1549

perror_plus("waitpid");

1550

free(fullname);

1551

continue;

1552

}

1553

if(WIFEXITED(status)){

1554

if(WEXITSTATUS(status) != 0){

1555

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1556

" with status %d\n", direntry->d_name,

1557

WEXITSTATUS(status));

1558

free(fullname);

1559

continue;

1560

}

1561

} else if(WIFSIGNALED(status)){

1562

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1563

" signal %d\n", direntry->d_name,

1564

WTERMSIG(status));

1565

free(fullname);

1566

continue;

1567

} else {

1568

fprintf_plus(stderr, "Warning: network hook \"%s\""

1569

" crashed\n", direntry->d_name);

1570

free(fullname);

1571

continue;

1572

}

1573

}

1574

free(fullname);

1575

if(debug){

1576

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1577

direntry->d_name);

1578

}

1579

}

1580

close(devnull);

1581

}

1582

return true;

2203

fprintf_plus(stderr, "Warning: network hook \"%s\""

2204

" crashed\n", direntry->d_name);

2205

free(direntry);

2206

continue;

2207

}

2208

}

2209

if(debug){

2210

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

2211

direntry->d_name);

2212

}

2213

free(direntry);

2214

}

2215

free(direntries);

2216

if(close(hookdir_fd) == -1){

2217

perror_plus("close");

2218

} else {

2219

hookdir_fd = -1;

2220

}

2221

close(devnull);

1583

2222

}

1584

2223

1585

error_t bring_up_interface(const char *const interface,

1586

const float delay){

1587

int sd = -1;

1588

error_t old_errno = errno;

1589

error_t ret_errno = 0;

1590

int ret, ret_setflags;

2224

__attribute__((nonnull, warn_unused_result))

2225

int bring_up_interface(const char *const interface,

2226

const float delay){

2227

int old_errno = errno;

2228

int ret;

1591

2229

struct ifreq network;

1592

2230

unsigned int if_index = if_nametoindex(interface);

1593

2231

if(if_index == 0){

1602

2240

}

1603

2241

1604

2242

if(not interface_is_up(interface)){

1605

if(not get_flags(interface, &network) and debug){

2243

int ret_errno = 0;

2244

int ioctl_errno = 0;

2245

if(not get_flags(interface, &network)){

1606

2246

ret_errno = errno;

1607

2247

fprintf_plus(stderr, "Failed to get flags for interface "

1608

2248

"\"%s\"\n", interface);

2249

errno = old_errno;

1609

2250

return ret_errno;

1610

2251

}

1611

network.ifr_flags |= IFF_UP;

2252

network.ifr_flags |= IFF_UP; /* set flag */

1612

2253

1613

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1614

if(sd < 0){

2254

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2255

if(sd == -1){

1615

2256

ret_errno = errno;

1616

2257

perror_plus("socket");

1617

2258

errno = old_errno;

1618

2259

return ret_errno;

1619

2260

}

1620

2261

1621

2262

if(quit_now){

1622

close(sd);

2263

ret = close(sd);

2264

if(ret == -1){

2265

perror_plus("close");

2266

}

1623

2267

errno = old_errno;

1624

2268

return EINTR;

1625

2269

}

1629

2273

interface);

1630

2274

}

1631

2275

1632

/* Raise priviliges */

1633

raise_privileges();

2276

/* Raise privileges */

2277

ret_errno = raise_privileges();

2278

if(ret_errno != 0){

2279

errno = ret_errno;

2280

perror_plus("Failed to raise privileges");

2281

}

1634

2282

1635

2283

#ifdef __linux__

1636

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1637

messages about the network interface to mess up the prompt */

1638

int ret_linux = klogctl(8, NULL, 5);

1639

bool restore_loglevel = true;

1640

if(ret_linux == -1){

1641

restore_loglevel = false;

1642

perror_plus("klogctl");

2284

int ret_linux;

2285

bool restore_loglevel = false;

2286

if(ret_errno == 0){

2287

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2288

messages about the network interface to mess up the prompt */

2289

ret_linux = klogctl(8, NULL, 5);

2290

if(ret_linux == -1){

2291

perror_plus("klogctl");

2292

} else {

2293

restore_loglevel = true;

2294

}

1643

2295

}

1644

2296

#endif /* __linux__ */

1645

ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

1646

ret_errno = errno;

2297

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2298

ioctl_errno = errno;

1647

2299

#ifdef __linux__

1648

2300

if(restore_loglevel){

1649

2301

ret_linux = klogctl(7, NULL, 0);

1653

2305

}

1654

2306

#endif /* __linux__ */

1655

2307

1656

/* Lower privileges */

1657

lower_privileges();

2308

/* If raise_privileges() succeeded above */

2309

if(ret_errno == 0){

2310

/* Lower privileges */

2311

ret_errno = lower_privileges();

2312

if(ret_errno != 0){

2313

errno = ret_errno;

2314

perror_plus("Failed to lower privileges");

2315

}

2316

}

1658

2317

1659

2318

/* Close the socket */

1660

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2319

ret = close(sd);

1661

2320

if(ret == -1){

1662

2321

perror_plus("close");

1663

2322

}

1664

2323

1665

2324

if(ret_setflags == -1){

1666

errno = ret_errno;

2325

errno = ioctl_errno;

1667

2326

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1668

2327

errno = old_errno;

1669

return ret_errno;

2328

return ioctl_errno;

1670

2329

}

1671

2330

} else if(debug){

1672

2331

fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",

1675

2334

1676

2335

/* Sleep checking until interface is running.

1677

2336

Check every 0.25s, up to total time of delay */

1678

for(int i=0; i < delay * 4; i++){

2337

for(int i = 0; i < delay * 4; i++){

1679

2338

if(interface_is_running(interface)){

1680

2339

break;

1681

2340

}

1690

2349

return 0;

1691

2350

}

1692

2351

1693

error_t take_down_interface(const char *const interface){

1694

int sd = -1;

1695

error_t old_errno = errno;

1696

error_t ret_errno = 0;

1697

int ret, ret_setflags;

2352

__attribute__((nonnull, warn_unused_result))

2353

int take_down_interface(const char *const interface){

2354

int old_errno = errno;

1698

2355

struct ifreq network;

1699

2356

unsigned int if_index = if_nametoindex(interface);

1700

2357

if(if_index == 0){

1703

2360

return ENXIO;

1704

2361

}

1705

2362

if(interface_is_up(interface)){

2363

int ret_errno = 0;

2364

int ioctl_errno = 0;

1706

2365

if(not get_flags(interface, &network) and debug){

1707

2366

ret_errno = errno;

1708

2367

fprintf_plus(stderr, "Failed to get flags for interface "

1709

2368

"\"%s\"\n", interface);

2369

errno = old_errno;

1710

2370

return ret_errno;

1711

2371

}

1712

2372

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

1713

2373

1714

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1715

if(sd < 0){

2374

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2375

if(sd == -1){

1716

2376

ret_errno = errno;

1717

2377

perror_plus("socket");

1718

2378

errno = old_errno;

1724

2384

interface);

1725

2385

}

1726

2386

1727

/* Raise priviliges */

1728

raise_privileges();

1729

1730

ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

1731

ret_errno = errno;

1732

1733

/* Lower privileges */

1734

lower_privileges();

2387

/* Raise privileges */

2388

ret_errno = raise_privileges();

2389

if(ret_errno != 0){

2390

errno = ret_errno;

2391

perror_plus("Failed to raise privileges");

2392

}

2393

2394

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2395

ioctl_errno = errno;

2396

2397

/* If raise_privileges() succeeded above */

2398

if(ret_errno == 0){

2399

/* Lower privileges */

2400

ret_errno = lower_privileges();

2401

if(ret_errno != 0){

2402

errno = ret_errno;

2403

perror_plus("Failed to lower privileges");

2404

}

2405

}

1735

2406

1736

2407

/* Close the socket */

1737

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2408

int ret = close(sd);

1738

2409

if(ret == -1){

1739

2410

perror_plus("close");

1740

2411

}

1741

2412

1742

2413

if(ret_setflags == -1){

1743

errno = ret_errno;

2414

errno = ioctl_errno;

1744

2415

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1745

2416

errno = old_errno;

1746

return ret_errno;

2417

return ioctl_errno;

1747

2418

}

1748

2419

} else if(debug){

1749

2420

fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",

1755

2426

}

1756

2427

1757

2428

int main(int argc, char *argv[]){

1758

mandos_context mc = { .server = NULL, .dh_bits = 1024,

1759

.priority = "SECURE256:!CTYPE-X.509:"

1760

"+CTYPE-OPENPGP", .current_server = NULL,

1761

.interfaces = NULL, .interfaces_size = 0 };

2429

mandos_context mc = { .server = NULL, .dh_bits = 0,

2430

.priority = "SECURE256:!CTYPE-X.509"

2431

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2432

.current_server = NULL, .interfaces = NULL,

2433

.interfaces_size = 0 };

1762

2434

AvahiSServiceBrowser *sb = NULL;

1763

2435

error_t ret_errno;

1764

2436

int ret;

1767

2439

int exitcode = EXIT_SUCCESS;

1768

2440

char *interfaces_to_take_down = NULL;

1769

2441

size_t interfaces_to_take_down_size = 0;

1770

char tempdir[] = "/tmp/mandosXXXXXX";

1771

bool tempdir_created = false;

2442

char run_tempdir[] = "/run/tmp/mandosXXXXXX";

2443

char old_tempdir[] = "/tmp/mandosXXXXXX";

2444

char *tempdir = NULL;

1772

2445

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1773

2446

const char *seckey = PATHDIR "/" SECKEY;

1774

2447

const char *pubkey = PATHDIR "/" PUBKEY;

2448

const char *dh_params_file = NULL;

1775

2449

char *interfaces_hooks = NULL;

1776

size_t interfaces_hooks_size = 0;

1777

2450

1778

2451

bool gnutls_initialized = false;

1779

2452

bool gpgme_initialized = false;

1831

2504

.doc = "Bit length of the prime number used in the"

1832

2505

" Diffie-Hellman key exchange",

1833

2506

.group = 2 },

2507

{ .name = "dh-params", .key = 134,

2508

.arg = "FILE",

2509

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2510

" for the Diffie-Hellman key exchange",

2511

.group = 2 },

1834

2512

{ .name = "priority", .key = 130,

1835

2513

.arg = "STRING",

1836

2514

.doc = "GnuTLS priority string for the TLS handshake",

1891

2569

}

1892

2570

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

1893

2571

break;

2572

case 134: /* --dh-params */

2573

dh_params_file = arg;

2574

break;

1894

2575

case 130: /* --priority */

1895

2576

mc.priority = arg;

1896

2577

break;

1936

2617

.args_doc = "",

1937

2618

.doc = "Mandos client -- Get and decrypt"

1938

2619

" passwords from a Mandos server" };

1939

ret = argp_parse(&argp, argc, argv,

1940

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1941

switch(ret){

2620

ret_errno = argp_parse(&argp, argc, argv,

2621

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2622

switch(ret_errno){

1942

2623

case 0:

1943

2624

break;

1944

2625

case ENOMEM:

1945

2626

default:

1946

errno = ret;

2627

errno = ret_errno;

1947

2628

perror_plus("argp_parse");

1948

2629

exitcode = EX_OSERR;

1949

2630

goto end;

1952

2633

goto end;

1953

2634

}

1954

2635

}

1955

2636

1956

2637

{

1957

2638

/* Work around Debian bug #633582:

1958

<http://bugs.debian.org/633582> */

2639

<https://bugs.debian.org/633582> */

1959

2640

1960

/* Re-raise priviliges */

1961

if(raise_privileges() == 0){

2641

/* Re-raise privileges */

2642

ret = raise_privileges();

2643

if(ret != 0){

2644

errno = ret;

2645

perror_plus("Failed to raise privileges");

2646

} else {

1962

2647

struct stat st;

1963

2648

1964

2649

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

1978

2663

}

1979

2664

}

1980

2665

}

1981

TEMP_FAILURE_RETRY(close(seckey_fd));

2666

close(seckey_fd);

1982

2667

}

1983

2668

}

1984

2669

1985

2670

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

1986

2671

int pubkey_fd = open(pubkey, O_RDONLY);

1987

2672

if(pubkey_fd == -1){

1999

2684

}

2000

2685

}

2001

2686

}

2002

TEMP_FAILURE_RETRY(close(pubkey_fd));

2003

}

2004

}

2005

2687

close(pubkey_fd);

2688

}

2689

}

2690

2691

if(dh_params_file != NULL

2692

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2693

int dhparams_fd = open(dh_params_file, O_RDONLY);

2694

if(dhparams_fd == -1){

2695

perror_plus("open");

2696

} else {

2697

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2698

if(ret == -1){

2699

perror_plus("fstat");

2700

} else {

2701

if(S_ISREG(st.st_mode)

2702

and st.st_uid == 0 and st.st_gid == 0){

2703

ret = fchown(dhparams_fd, uid, gid);

2704

if(ret == -1){

2705

perror_plus("fchown");

2706

}

2707

}

2708

}

2709

close(dhparams_fd);

2710

}

2711

}

2712

2006

2713

/* Lower privileges */

2007

errno = 0;

2008

ret = seteuid(uid);

2009

if(ret == -1){

2010

perror_plus("seteuid");

2714

ret = lower_privileges();

2715

if(ret != 0){

2716

errno = ret;

2717

perror_plus("Failed to lower privileges");

2011

2718

}

2012

2719

}

2013

2720

}

2014

2721

2015

/* Remove empty interface names */

2722

/* Remove invalid interface names (except "none") */

2016

2723

{

2017

2724

char *interface = NULL;

2018

2725

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2019

2726

interface))){

2020

if(if_nametoindex(interface) == 0){

2021

if(interface[0] != '\0' and strcmp(interface, "none") != 0){

2727

if(strcmp(interface, "none") != 0

2728

and if_nametoindex(interface) == 0){

2729

if(interface[0] != '\0'){

2022

2730

fprintf_plus(stderr, "Not using nonexisting interface"

2023

2731

" \"%s\"\n", interface);

2024

2732

}

2030

2738

2031

2739

/* Run network hooks */

2032

2740

{

2033

2034

2741

if(mc.interfaces != NULL){

2035

2742

interfaces_hooks = malloc(mc.interfaces_size);

2036

2743

if(interfaces_hooks == NULL){

2038

2745

goto end;

2039

2746

}

2040

2747

memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);

2041

interfaces_hooks_size = mc.interfaces_size;

2042

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2043

(int)',');

2044

}

2045

if(not run_network_hooks("start", interfaces_hooks != NULL ?

2046

interfaces_hooks : "", delay)){

2047

goto end;

2048

}

2748

argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');

2749

}

2750

run_network_hooks("start", interfaces_hooks != NULL ?

2751

interfaces_hooks : "", delay);

2049

2752

}

2050

2753

2051

2754

if(not debug){

2129

2832

2130

2833

/* If no interfaces were specified, make a list */

2131

2834

if(mc.interfaces == NULL){

2132

struct dirent **direntries;

2835

struct dirent **direntries = NULL;

2133

2836

/* Look for any good interfaces */

2134

2837

ret = scandir(sys_class_net, &direntries, good_interface,

2135

2838

alphasort);

2139

2842

ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,

2140

2843

direntries[i]->d_name);

2141

2844

if(ret_errno != 0){

2845

errno = ret_errno;

2142

2846

perror_plus("argz_add");

2847

free(direntries[i]);

2143

2848

continue;

2144

2849

}

2145

2850

if(debug){

2146

2851

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2147

2852

direntries[i]->d_name);

2148

2853

}

2854

free(direntries[i]);

2149

2855

}

2150

2856

free(direntries);

2151

2857

} else {

2152

free(direntries);

2858

if(ret == 0){

2859

free(direntries);

2860

}

2153

2861

fprintf_plus(stderr, "Could not find a network interface\n");

2154

2862

exitcode = EXIT_FAILURE;

2155

2863

goto end;

2156

2864

}

2157

2865

}

2158

2866

2867

/* Bring up interfaces which are down, and remove any "none"s */

2868

{

2869

char *interface = NULL;

2870

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2871

interface))){

2872

/* If interface name is "none", stop bringing up interfaces.

2873

Also remove all instances of "none" from the list */

2874

if(strcmp(interface, "none") == 0){

2875

argz_delete(&mc.interfaces, &mc.interfaces_size,

2876

interface);

2877

interface = NULL;

2878

while((interface = argz_next(mc.interfaces,

2879

mc.interfaces_size, interface))){

2880

if(strcmp(interface, "none") == 0){

2881

argz_delete(&mc.interfaces, &mc.interfaces_size,

2882

interface);

2883

interface = NULL;

2884

}

2885

}

2886

break;

2887

}

2888

bool interface_was_up = interface_is_up(interface);

2889

errno = bring_up_interface(interface, delay);

2890

if(not interface_was_up){

2891

if(errno != 0){

2892

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2893

" %s\n", interface, strerror(errno));

2894

} else {

2895

errno = argz_add(&interfaces_to_take_down,

2896

&interfaces_to_take_down_size,

2897

interface);

2898

if(errno != 0){

2899

perror_plus("argz_add");

2900

}

2901

}

2902

}

2903

}

2904

if(debug and (interfaces_to_take_down == NULL)){

2905

fprintf_plus(stderr, "No interfaces were brought up\n");

2906

}

2907

}

2908

2159

2909

/* If we only got one interface, explicitly use only that one */

2160

2910

if(argz_count(mc.interfaces, mc.interfaces_size) == 1){

2161

2911

if(debug){

2165

2915

if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);

2166

2916

}

2167

2917

2168

/* Bring up interfaces which are down */

2169

if(not (argz_count(mc.interfaces, mc.interfaces_size) == 1

2170

and strcmp(mc.interfaces, "none") == 0)){

2171

char *interface = NULL;

2172

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2173

interface))){

2174

bool interface_was_up = interface_is_up(interface);

2175

ret = bring_up_interface(interface, delay);

2176

if(not interface_was_up){

2177

if(ret != 0){

2178

errno = ret;

2179

perror_plus("Failed to bring up interface");

2180

} else {

2181

ret_errno = argz_add(&interfaces_to_take_down,

2182

&interfaces_to_take_down_size,

2183

interface);

2184

}

2185

}

2186

}

2187

free(mc.interfaces);

2188

mc.interfaces = NULL;

2189

mc.interfaces_size = 0;

2190

if(debug and (interfaces_to_take_down == NULL)){

2191

fprintf_plus(stderr, "No interfaces were brought up\n");

2192

}

2193

}

2194

2195

2918

if(quit_now){

2196

2919

goto end;

2197

2920

}

2198

2921

2199

ret = init_gnutls_global(pubkey, seckey, &mc);

2922

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

2200

2923

if(ret == -1){

2201

2924

fprintf_plus(stderr, "init_gnutls_global failed\n");

2202

2925

exitcode = EX_UNAVAILABLE;

2209

2932

goto end;

2210

2933

}

2211

2934

2212

if(mkdtemp(tempdir) == NULL){

2935

/* Try /run/tmp before /tmp */

2936

tempdir = mkdtemp(run_tempdir);

2937

if(tempdir == NULL and errno == ENOENT){

2938

if(debug){

2939

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

2940

run_tempdir, old_tempdir);

2941

}

2942

tempdir = mkdtemp(old_tempdir);

2943

}

2944

if(tempdir == NULL){

2213

2945

perror_plus("mkdtemp");

2214

2946

goto end;

2215

2947

}

2216

tempdir_created = true;

2217

2948

2218

2949

if(quit_now){

2219

2950

goto end;

2255

2986

exitcode = EX_USAGE;

2256

2987

goto end;

2257

2988

}

2258

2989

2259

2990

if(quit_now){

2260

2991

goto end;

2261

2992

}

2291

3022

fprintf_plus(stderr, "Retrying in %d seconds\n",

2292

3023

(int)retry_interval);

2293

3024

}

2294

sleep((int)retry_interval);

3025

sleep((unsigned int)retry_interval);

2295

3026

}

2296

3027

2297

if (not quit_now){

3028

if(not quit_now){

2298

3029

exitcode = EXIT_SUCCESS;

2299

3030

}

2300

3031

2316

3047

2317

3048

/* Allocate a new server */

2318

3049

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2319

&config, NULL, NULL, &ret_errno);

3050

&config, NULL, NULL, &ret);

2320

3051

2321

3052

/* Free the Avahi configuration data */

2322

3053

avahi_server_config_free(&config);

2325

3056

/* Check if creating the Avahi server object succeeded */

2326

3057

if(mc.server == NULL){

2327

3058

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2328

avahi_strerror(ret_errno));

3059

avahi_strerror(ret));

2329

3060

exitcode = EX_UNAVAILABLE;

2330

3061

goto end;

2331

3062

}

2355

3086

if(debug){

2356

3087

fprintf_plus(stderr, "Starting Avahi loop search\n");

2357

3088

}

2358

3089

2359

3090

ret = avahi_loop_with_timeout(simple_poll,

2360

3091

(int)(retry_interval * 1000), &mc);

2361

3092

if(debug){

2366

3097

end:

2367

3098

2368

3099

if(debug){

2369

fprintf_plus(stderr, "%s exiting\n", argv[0]);

3100

if(signal_received){

3101

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

3102

argv[0], signal_received,

3103

strsignal(signal_received));

3104

} else {

3105

fprintf_plus(stderr, "%s exiting\n", argv[0]);

3106

}

2370

3107

}

2371

3108

2372

3109

/* Cleanup things */

3110

free(mc.interfaces);

3111

2373

3112

if(sb != NULL)

2374

3113

avahi_s_service_browser_free(sb);

2375

3114

2381

3120

2382

3121

if(gnutls_initialized){

2383

3122

gnutls_certificate_free_credentials(mc.cred);

2384

gnutls_global_deinit();

2385

3123

gnutls_dh_params_deinit(mc.dh_params);

2386

3124

}

2387

3125

2395

3133

mc.current_server->prev->next = NULL;

2396

3134

while(mc.current_server != NULL){

2397

3135

server *next = mc.current_server->next;

3136

#ifdef __GNUC__

3137

#pragma GCC diagnostic push

3138

#pragma GCC diagnostic ignored "-Wcast-qual"

3139

#endif

3140

free((char *)(mc.current_server->ip));

3141

#ifdef __GNUC__

3142

#pragma GCC diagnostic pop

3143

#endif

2398

3144

free(mc.current_server);

2399

3145

mc.current_server = next;

2400

3146

}

2401

3147

}

2402

3148

2403

/* Re-raise priviliges */

3149

/* Re-raise privileges */

2404

3150

{

2405

raise_privileges();

2406

2407

/* Run network hooks */

2408

run_network_hooks("stop", interfaces_hooks != NULL ?

2409

interfaces_hooks : "", delay);

2410

2411

/* Take down the network interfaces which were brought up */

2412

{

2413

char *interface = NULL;

2414

while((interface=argz_next(interfaces_to_take_down,

2415

interfaces_to_take_down_size,

2416

interface))){

2417

ret_errno = take_down_interface(interface);

2418

if(ret_errno != 0){

2419

errno = ret_errno;

2420

perror_plus("Failed to take down interface");

2421

}

2422

}

2423

if(debug and (interfaces_to_take_down == NULL)){

2424

fprintf_plus(stderr, "No interfaces needed to be taken"

2425

" down\n");

2426

}

2427

}

2428

2429

lower_privileges_permanently();

3151

ret = raise_privileges();

3152

if(ret != 0){

3153

errno = ret;

3154

perror_plus("Failed to raise privileges");

3155

} else {

3156

3157

/* Run network hooks */

3158

run_network_hooks("stop", interfaces_hooks != NULL ?

3159

interfaces_hooks : "", delay);

3160

3161

/* Take down the network interfaces which were brought up */

3162

{

3163

char *interface = NULL;

3164

while((interface = argz_next(interfaces_to_take_down,

3165

interfaces_to_take_down_size,

3166

interface))){

3167

ret = take_down_interface(interface);

3168

if(ret != 0){

3169

errno = ret;

3170

perror_plus("Failed to take down interface");

3171

}

3172

}

3173

if(debug and (interfaces_to_take_down == NULL)){

3174

fprintf_plus(stderr, "No interfaces needed to be taken"

3175

" down\n");

3176

}

3177

}

3178

}

3179

3180

ret = lower_privileges_permanently();

3181

if(ret != 0){

3182

errno = ret;

3183

perror_plus("Failed to lower privileges permanently");

3184

}

2430

3185

}

2431

3186

2432

3187

free(interfaces_to_take_down);

2433

3188

free(interfaces_hooks);

2434

3189

3190

void clean_dir_at(int base, const char * const dirname,

3191

uintmax_t level){

3192

struct dirent **direntries = NULL;

3193

int dret;

3194

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3195

O_RDONLY

3196

| O_NOFOLLOW

3197

| O_DIRECTORY

3198

| O_PATH));

3199

if(dir_fd == -1){

3200

perror_plus("open");

3201

return;

3202

}

3203

int numentries = scandirat(dir_fd, ".", &direntries,

3204

notdotentries, alphasort);

3205

if(numentries >= 0){

3206

for(int i = 0; i < numentries; i++){

3207

if(debug){

3208

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3209

dirname, direntries[i]->d_name);

3210

}

3211

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3212

if(dret == -1){

3213

if(errno == EISDIR){

3214

dret = unlinkat(dir_fd, direntries[i]->d_name,

3215

AT_REMOVEDIR);

3216

}

3217

if((dret == -1) and (errno == ENOTEMPTY)

3218

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3219

== 0) and (level == 0)){

3220

/* Recurse only in this special case */

3221

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3222

dret = 0;

3223

}

3224

if((dret == -1) and (errno != ENOENT)){

3225

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3226

direntries[i]->d_name, strerror(errno));

3227

}

3228

}

3229

free(direntries[i]);

3230

}

3231

3232

/* need to clean even if 0 because man page doesn't specify */

3233

free(direntries);

3234

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3235

if(dret == -1 and errno != ENOENT){

3236

perror_plus("rmdir");

3237

}

3238

} else {

3239

perror_plus("scandirat");

3240

}

3241

close(dir_fd);

3242

}

3243

2435

3244

/* Removes the GPGME temp directory and all files inside */

2436

if(tempdir_created){

2437

struct dirent **direntries = NULL;

2438

struct dirent *direntry = NULL;

2439

int numentries = scandir(tempdir, &direntries, notdotentries,

2440

alphasort);

2441

if (numentries > 0){

2442

for(int i = 0; i < numentries; i++){

2443

direntry = direntries[i];

2444

char *fullname = NULL;

2445

ret = asprintf(&fullname, "%s/%s", tempdir,

2446

direntry->d_name);

2447

if(ret < 0){

2448

perror_plus("asprintf");

2449

continue;

2450

}

2451

ret = remove(fullname);

2452

if(ret == -1){

2453

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2454

strerror(errno));

2455

}

2456

free(fullname);

2457

}

2458

}

2459

2460

/* need to clean even if 0 because man page doesn't specify */

2461

free(direntries);

2462

if (numentries == -1){

2463

perror_plus("scandir");

2464

}

2465

ret = rmdir(tempdir);

2466

if(ret == -1 and errno != ENOENT){

2467

perror_plus("rmdir");

2468

}

3245

if(tempdir != NULL){

3246

clean_dir_at(-1, tempdir, 0);

2469

3247

}

2470

3248

2471

3249

if(quit_now){