/mandos/trunk : revision 666

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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 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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*

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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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* WITHOUT ANY WARRANTY; without even the implied warranty of

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22

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

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* along with this program. If not, see

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* <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 /* not _LARGEFILE_SOURCE */

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#endif

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif /* not _FILE_OFFSET_BITS */

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#endif

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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() */

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stdout, ferror(), remove() */

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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 */

50

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

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asprintf(), strncpy(), strsignal()

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*/

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

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

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51

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

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52

#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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getnameinfo() */

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

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inet_pton(), connect() */

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

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

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61

*/

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

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63

strtoimax() */

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

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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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unlinkat() */

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

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

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

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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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105

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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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143

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perror(print_text);

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}

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

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

195

184

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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* 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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198

size_t incbuffer(char **buffer, size_t buffer_length,

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size_t buffer_capacity){

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200

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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}

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

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__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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int af, server **current_server){

231

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int ret;

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.af = af };

241

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if(new_server->ip == NULL){

242

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perror_plus("strdup");

243

free(new_server);

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return false;

245

}

246

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

247

if(ret == -1){

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perror_plus("clock_gettime");

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#ifdef __GNUC__

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#pragma GCC diagnostic push

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#pragma GCC diagnostic ignored "-Wcast-qual"

252

#endif

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

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#ifdef __GNUC__

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#pragma GCC diagnostic pop

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#endif

257

free(new_server);

258

230

return false;

259

231

}

260

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/* Special case of first server */

262

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new_server->next = new_server;

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new_server->prev = new_server;

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*current_server = new_server;

237

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

265

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} else {

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

267

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new_server->next = *current_server;

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

269

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new_server->prev->next = new_server;

270

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(*current_server)->prev = new_server;

271

243

}

244

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

245

if(ret == -1){

246

perror_plus("clock_gettime");

247

return false;

248

}

272

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return true;

273

250

}

274

251

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/* 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

327

252

/*

328

253

* Initialize GPGME.

329

254

*/

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){

255

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

256

const char *tempdir, mandos_context *mc){

335

257

gpgme_error_t rc;

336

258

gpgme_engine_info_t engine_info;

337

259

338

260

/*

339

261

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

340

262

*/

341

bool import_key(const char * const filename){

263

bool import_key(const char *filename){

342

264

int ret;

343

265

int fd;

344

266

gpgme_data_t pgp_data;

349

271

return false;

350

272

}

351

273

352

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

353

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){

364

break;

365

}

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");

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break;

380

}

381

ret = raise_privileges();

382

if(ret != 0){

383

errno = ret;

384

perror_plus("Failed to raise privileges");

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break;

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}

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

402

274

rc = gpgme_data_new_from_fd(&pgp_data, fd);

403

275

if(rc != GPG_ERR_NO_ERROR){

404

276

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

412

284

gpgme_strsource(rc), gpgme_strerror(rc));

413

285

return false;

414

286

}

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

}

490

287

491

ret = close(fd);

288

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

492

289

if(ret == -1){

493

290

perror_plus("close");

494

291

}

533

330

/* Create new GPGME "context" */

534

331

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

535

332

if(rc != GPG_ERR_NO_ERROR){

536

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

537

gpgme_strsource(rc), gpgme_strerror(rc));

333

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

334

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

335

gpgme_strerror(rc));

538

336

return false;

539

337

}

540

338

549

347

* Decrypt OpenPGP data.

550

348

* Returns -1 on error

551

349

*/

552

__attribute__((nonnull, warn_unused_result))

553

350

static ssize_t pgp_packet_decrypt(const char *cryptotext,

554

351

size_t crypto_size,

555

352

char **plaintext,

576

373

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

577

374

rc = gpgme_data_new(&dh_plain);

578

375

if(rc != GPG_ERR_NO_ERROR){

579

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

376

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

377

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

580

378

gpgme_strsource(rc), gpgme_strerror(rc));

581

379

gpgme_data_release(dh_crypto);

582

380

return -1;

595

393

if(result == NULL){

596

394

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

597

395

} else {

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");

396

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

397

result->unsupported_algorithm);

398

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

399

result->wrong_key_usage);

604

400

if(result->file_name != NULL){

605

401

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

606

402

}

607

608

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

609

r = r->next){

403

gpgme_recipient_t recipient;

404

recipient = result->recipients;

405

while(recipient != NULL){

610

406

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

611

gpgme_pubkey_algo_name(r->pubkey_algo));

612

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

407

gpgme_pubkey_algo_name

408

(recipient->pubkey_algo));

409

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

613

410

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

614

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

411

recipient->status == GPG_ERR_NO_SECKEY

412

? "No" : "Yes");

413

recipient = recipient->next;

615

414

}

616

415

}

617

416

}

673

472

return plaintext_length;

674

473

}

675

474

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){

475

static const char * safer_gnutls_strerror(int value){

685

476

const char *ret = gnutls_strerror(value);

686

return safe_string(ret);

477

if(ret == NULL)

478

ret = "(unknown)";

479

return ret;

687

480

}

688

481

689

482

/* GnuTLS log function callback */

690

__attribute__((nonnull))

691

483

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

692

484

const char* string){

693

485

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

694

486

}

695

487

696

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

697

488

static int init_gnutls_global(const char *pubkeyfilename,

698

489

const char *seckeyfilename,

699

const char *dhparamsfilename,

700

490

mandos_context *mc){

701

491

int ret;

702

unsigned int uret;

703

492

704

493

if(debug){

705

494

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

706

495

}

707

496

497

ret = gnutls_global_init();

498

if(ret != GNUTLS_E_SUCCESS){

499

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

500

safer_gnutls_strerror(ret));

501

return -1;

502

}

503

708

504

if(debug){

709

505

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

710

506

* - GnuTLS manual

718

514

if(ret != GNUTLS_E_SUCCESS){

719

515

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

720

516

safer_gnutls_strerror(ret));

517

gnutls_global_deinit();

721

518

return -1;

722

519

}

723

520

748

545

safer_gnutls_strerror(ret));

749

546

goto globalfail;

750

547

}

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

}

548

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

549

if(ret != GNUTLS_E_SUCCESS){

550

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

551

safer_gnutls_strerror(ret));

552

goto globalfail;

553

}

554

928

555

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

929

556

930

557

return 0;

932

559

globalfail:

933

560

934

561

gnutls_certificate_free_credentials(mc->cred);

562

gnutls_global_deinit();

935

563

gnutls_dh_params_deinit(mc->dh_params);

936

564

return -1;

937

565

}

938

566

939

__attribute__((nonnull, warn_unused_result))

940

567

static int init_gnutls_session(gnutls_session_t *session,

941

568

mandos_context *mc){

942

569

int ret;

989

616

/* ignore client certificate if any. */

990

617

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

991

618

619

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

620

992

621

return 0;

993

622

}

994

623

996

625

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

997

626

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

998

627

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

1165

628

/* Called when a Mandos server is found */

1166

__attribute__((nonnull, warn_unused_result))

1167

629

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

1168

630

AvahiIfIndex if_index,

1169

631

int af, mandos_context *mc){

1170

632

int ret, tcp_sd = -1;

1171

633

ssize_t sret;

1172

struct sockaddr_storage to;

634

union {

635

struct sockaddr_in in;

636

struct sockaddr_in6 in6;

637

} to;

1173

638

char *buffer = NULL;

1174

639

char *decrypted_buffer = NULL;

1175

640

size_t buffer_length = 0;

1178

643

int retval = -1;

1179

644

gnutls_session_t session;

1180

645

int pf; /* Protocol family */

1181

bool route_added = false;

1182

646

1183

647

errno = 0;

1184

648

1206

670

bool match = false;

1207

671

{

1208

672

char *interface = NULL;

1209

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

1210

mc->interfaces_size,

1211

interface))){

673

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

674

interface))){

1212

675

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

1213

676

match = true;

1214

677

break;

1243

706

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

1244

707

}

1245

708

1246

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

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1247

710

if(tcp_sd < 0){

1248

711

int e = errno;

1249

712

perror_plus("socket");

1256

719

goto mandos_end;

1257

720

}

1258

721

722

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

1259

723

if(af == AF_INET6){

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);

724

to.in6.sin6_family = (sa_family_t)af;

725

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

1263

726

} else { /* IPv4 */

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);

727

to.in.sin_family = (sa_family_t)af;

728

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

1267

729

}

1268

730

if(ret < 0 ){

1269

731

int e = errno;

1278

740

goto mandos_end;

1279

741

}

1280

742

if(af == AF_INET6){

1281

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

1282

if(IN6_IS_ADDR_LINKLOCAL

1283

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

743

to.in6.sin6_port = htons(port);

744

#ifdef __GNUC__

745

#pragma GCC diagnostic push

746

#pragma GCC diagnostic ignored "-Wstrict-aliasing"

747

#endif

748

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

749

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

750

#ifdef __GNUC__

751

#pragma GCC diagnostic pop

752

#endif

1284

753

if(if_index == AVAHI_IF_UNSPEC){

1285

754

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

1286

755

" incomplete without a network interface\n");

1288

757

goto mandos_end;

1289

758

}

1290

759

/* Set the network interface number as scope */

1291

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

760

to.in6.sin6_scope_id = (uint32_t)if_index;

1292

761

}

1293

762

} else {

1294

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

763

to.in.sin_port = htons(port);

1295

764

}

1296

765

1297

766

if(quit_now){

1314

783

}

1315

784

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1316

785

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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;

786

const char *pcret;

787

if(af == AF_INET6){

788

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

789

sizeof(addrstr));

790

} else {

791

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

792

sizeof(addrstr));

793

}

794

if(pcret == NULL){

795

perror_plus("inet_ntop");

796

} else {

797

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

798

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

799

}

800

}

801

}

802

803

if(quit_now){

804

errno = EINTR;

805

goto mandos_end;

806

}

807

808

if(af == AF_INET6){

809

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

810

} else {

811

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

812

}

813

if(ret < 0){

814

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

815

int e = errno;

816

perror_plus("connect");

817

errno = e;

818

}

819

goto mandos_end;

820

}

821

822

if(quit_now){

823

errno = EINTR;

824

goto mandos_end;

1397

825

}

1398

826

1399

827

const char *out = mandos_protocol_version;

1553

981

&decrypted_buffer, mc);

1554

982

if(decrypted_buffer_size >= 0){

1555

983

1556

clearerr(stdout);

1557

984

written = 0;

1558

985

while(written < (size_t) decrypted_buffer_size){

1559

986

if(quit_now){

1575

1002

}

1576

1003

written += (size_t)ret;

1577

1004

}

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

}

1588

1005

retval = 0;

1589

1006

}

1590

1007

}

1593

1010

1594

1011

mandos_end:

1595

1012

{

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

}

1602

1013

int e = errno;

1603

1014

free(decrypted_buffer);

1604

1015

free(buffer);

1605

1016

if(tcp_sd >= 0){

1606

ret = close(tcp_sd);

1017

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

1607

1018

}

1608

1019

if(ret == -1){

1609

1020

if(e == 0){

1634

1045

AVAHI_GCC_UNUSED AvahiStringList *txt,

1635

1046

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1636

1047

flags,

1637

void *mc){

1048

void* mc){

1638

1049

if(r == NULL){

1639

1050

return;

1640

1051

}

1643

1054

timed out */

1644

1055

1645

1056

if(quit_now){

1646

avahi_s_service_resolver_free(r);

1647

1057

return;

1648

1058

}

1649

1059

1694

1104

const char *domain,

1695

1105

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1696

1106

flags,

1697

void *mc){

1107

void* mc){

1698

1108

if(b == NULL){

1699

1109

return;

1700

1110

}

1760

1170

errno = old_errno;

1761

1171

}

1762

1172

1763

__attribute__((nonnull, warn_unused_result))

1764

1173

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

1765

1174

int ret;

1766

int old_errno;

1175

error_t ret_errno;

1767

1176

1768

1177

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

1769

1178

if(s < 0){

1770

old_errno = errno;

1179

ret_errno = errno;

1771

1180

perror_plus("socket");

1772

errno = old_errno;

1181

errno = ret_errno;

1773

1182

return false;

1774

1183

}

1775

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

1776

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

1184

strcpy(ifr->ifr_name, ifname);

1777

1185

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1778

1186

if(ret == -1){

1779

1187

if(debug){

1780

old_errno = errno;

1188

ret_errno = errno;

1781

1189

perror_plus("ioctl SIOCGIFFLAGS");

1782

errno = old_errno;

1783

}

1784

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

1785

old_errno = errno;

1786

perror_plus("close");

1787

errno = old_errno;

1190

errno = ret_errno;

1788

1191

}

1789

1192

return false;

1790

1193

}

1791

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

1792

old_errno = errno;

1793

perror_plus("close");

1794

errno = old_errno;

1795

}

1796

1194

return true;

1797

1195

}

1798

1196

1799

__attribute__((nonnull, warn_unused_result))

1800

1197

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

1801

1198

1802

1199

/* Reject the loopback device */

1844

1241

* corresponds to an acceptable network device.

1845

1242

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

1846

1243

*/

1847

__attribute__((nonnull, warn_unused_result))

1848

1244

int good_interface(const struct dirent *if_entry){

1849

1245

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

1850

1246

return 0;

1868

1264

/*

1869

1265

* This function determines if a network interface is up.

1870

1266

*/

1871

__attribute__((nonnull, warn_unused_result))

1872

1267

bool interface_is_up(const char *interface){

1873

1268

struct ifreq ifr;

1874

1269

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

1885

1280

/*

1886

1281

* This function determines if a network interface is running

1887

1282

*/

1888

__attribute__((nonnull, warn_unused_result))

1889

1283

bool interface_is_running(const char *interface){

1890

1284

struct ifreq ifr;

1891

1285

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

1899

1293

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

1900

1294

}

1901

1295

1902

__attribute__((nonnull, pure, warn_unused_result))

1903

1296

int notdotentries(const struct dirent *direntry){

1904

1297

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

1905

1298

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

1912

1305

}

1913

1306

1914

1307

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

1915

__attribute__((nonnull, warn_unused_result))

1916

1308

int runnable_hook(const struct dirent *direntry){

1917

1309

int ret;

1918

1310

size_t sret;

1926

1318

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

1927

1319

"abcdefghijklmnopqrstuvwxyz"

1928

1320

"0123456789"

1929

"_.-");

1321

"_-");

1930

1322

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

1931

1323

/* Contains non-allowed characters */

1932

1324

if(debug){

1936

1328

return 0;

1937

1329

}

1938

1330

1939

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

1331

char *fullname = NULL;

1332

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

1333

if(ret < 0){

1334

perror_plus("asprintf");

1335

return 0;

1336

}

1337

1338

ret = stat(fullname, &st);

1940

1339

if(ret == -1){

1941

1340

if(debug){

1942

1341

perror_plus("Could not stat hook");

1966

1365

return 1;

1967

1366

}

1968

1367

1969

__attribute__((nonnull, warn_unused_result))

1970

1368

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1971

1369

mandos_context *mc){

1972

1370

int ret;

1976

1374

1977

1375

while(true){

1978

1376

if(mc->current_server == NULL){

1979

if(debug){

1377

if (debug){

1980

1378

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

1981

1379

" No timeout!\n");

1982

1380

}

1983

1381

ret = avahi_simple_poll_iterate(s, -1);

1984

1382

} else {

1985

if(debug){

1383

if (debug){

1986

1384

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

1987

1385

" it, or wait\n");

1988

1386

}

2005

1403

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

2006

1404

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

2007

1405

2008

if(debug){

1406

if (debug){

2009

1407

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

2010

1408

block_time);

2011

1409

}

2033

1431

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

2034

1432

}

2035

1433

if(ret != 0){

2036

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

1434

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

2037

1435

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

2038

1436

}

2039

1437

}

2040

1438

}

2041

1439

}

2042

1440

2043

__attribute__((nonnull))

2044

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

1441

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

1442

error_t raise_privileges(void){

1443

error_t old_errno = errno;

1444

error_t ret_errno = 0;

1445

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

1446

ret_errno = errno;

1447

perror_plus("seteuid");

1448

}

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

1453

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

1454

error_t raise_privileges_permanently(void){

1455

error_t old_errno = errno;

1456

error_t ret_errno = raise_privileges();

1457

if(ret_errno != 0){

1458

errno = old_errno;

1459

return ret_errno;

1460

}

1461

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

1462

ret_errno = errno;

1463

perror_plus("seteuid");

1464

}

1465

errno = old_errno;

1466

return ret_errno;

1467

}

1468

1469

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

1470

error_t lower_privileges(void){

1471

error_t old_errno = errno;

1472

error_t ret_errno = 0;

1473

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

1474

ret_errno = errno;

1475

perror_plus("seteuid");

1476

}

1477

errno = old_errno;

1478

return ret_errno;

1479

}

1480

1481

/* Lower privileges permanently */

1482

error_t lower_privileges_permanently(void){

1483

error_t old_errno = errno;

1484

error_t ret_errno = 0;

1485

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

1486

ret_errno = errno;

1487

perror_plus("setuid");

1488

}

1489

errno = old_errno;

1490

return ret_errno;

1491

}

1492

1493

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

2045

1494

const float delay){

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);

1495

struct dirent **direntries;

1496

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

1497

alphasort);

2069

1498

if(numhooks == -1){

2070

perror_plus("scandir");

2071

close(devnull);

2072

return;

2073

}

2074

struct dirent *direntry;

2075

int ret;

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);

1499

if(errno == ENOENT){

1500

if(debug){

1501

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

1502

" found\n", hookdir);

1503

}

1504

} else {

1505

perror_plus("scandir");

2081

1506

}

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){

1507

} else {

1508

struct dirent *direntry;

1509

int ret;

1510

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

1511

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

1512

direntry = direntries[i];

1513

char *fullname = NULL;

1514

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

1515

if(ret < 0){

2128

1516

perror_plus("asprintf");

2129

_exit(EX_OSERR);

2130

}

2131

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

2132

if(ret == -1){

1517

continue;

1518

}

1519

if(debug){

1520

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

1521

direntry->d_name);

1522

}

1523

pid_t hook_pid = fork();

1524

if(hook_pid == 0){

1525

/* Child */

1526

/* Raise privileges */

1527

raise_privileges_permanently();

1528

/* Set group */

1529

errno = 0;

1530

ret = setgid(0);

1531

if(ret == -1){

1532

perror_plus("setgid");

1533

}

1534

/* Reset supplementary groups */

1535

errno = 0;

1536

ret = setgroups(0, NULL);

1537

if(ret == -1){

1538

perror_plus("setgroups");

1539

}

1540

dup2(devnull, STDIN_FILENO);

1541

close(devnull);

1542

dup2(STDERR_FILENO, STDOUT_FILENO);

1543

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

1544

if(ret == -1){

1545

perror_plus("setenv");

1546

_exit(EX_OSERR);

1547

}

1548

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

1549

if(ret == -1){

1550

perror_plus("setenv");

1551

_exit(EX_OSERR);

1552

}

1553

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

1554

if(ret == -1){

1555

perror_plus("setenv");

1556

_exit(EX_OSERR);

1557

}

1558

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

1559

if(ret == -1){

1560

perror_plus("setenv");

1561

_exit(EX_OSERR);

1562

}

1563

char *delaystring;

1564

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

1565

if(ret == -1){

1566

perror_plus("asprintf");

1567

_exit(EX_OSERR);

1568

}

1569

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

1570

if(ret == -1){

1571

free(delaystring);

1572

perror_plus("setenv");

1573

_exit(EX_OSERR);

1574

}

2133

1575

free(delaystring);

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;

1576

if(connect_to != NULL){

1577

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

1578

if(ret == -1){

1579

perror_plus("setenv");

1580

_exit(EX_OSERR);

1581

}

1582

}

1583

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

1584

perror_plus("execl");

1585

_exit(EXIT_FAILURE);

1586

}

2202

1587

} else {

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);

1588

int status;

1589

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

1590

perror_plus("waitpid");

1591

free(fullname);

1592

continue;

1593

}

1594

if(WIFEXITED(status)){

1595

if(WEXITSTATUS(status) != 0){

1596

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

1597

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

1598

WEXITSTATUS(status));

1599

free(fullname);

1600

continue;

1601

}

1602

} else if(WIFSIGNALED(status)){

1603

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

1604

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

1605

WTERMSIG(status));

1606

free(fullname);

1607

continue;

1608

} else {

1609

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

1610

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

1611

free(fullname);

1612

continue;

1613

}

1614

}

1615

free(fullname);

1616

if(debug){

1617

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

1618

direntry->d_name);

1619

}

1620

}

1621

close(devnull);

1622

}

1623

return true;

2222

1624

}

2223

1625

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;

1626

error_t bring_up_interface(const char *const interface,

1627

const float delay){

1628

int sd = -1;

1629

error_t old_errno = errno;

1630

error_t ret_errno = 0;

1631

int ret, ret_setflags;

2229

1632

struct ifreq network;

2230

1633

unsigned int if_index = if_nametoindex(interface);

2231

1634

if(if_index == 0){

2240

1643

}

2241

1644

2242

1645

if(not interface_is_up(interface)){

2243

int ret_errno = 0;

2244

int ioctl_errno = 0;

2245

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

1646

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

2246

1647

ret_errno = errno;

2247

1648

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

2248

1649

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

2249

errno = old_errno;

2250

1650

return ret_errno;

2251

1651

}

2252

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

1652

network.ifr_flags |= IFF_UP;

2253

1653

2254

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

2255

if(sd == -1){

1654

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1655

if(sd < 0){

2256

1656

ret_errno = errno;

2257

1657

perror_plus("socket");

2258

1658

errno = old_errno;

2259

1659

return ret_errno;

2260

1660

}

2261

1661

2262

1662

if(quit_now){

2263

ret = close(sd);

2264

if(ret == -1){

2265

perror_plus("close");

2266

}

1663

close(sd);

2267

1664

errno = old_errno;

2268

1665

return EINTR;

2269

1666

}

2273

1670

interface);

2274

1671

}

2275

1672

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

}

1673

/* Raise priviliges */

1674

raise_privileges();

2282

1675

2283

1676

#ifdef __linux__

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

}

1677

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1678

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

1679

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

1680

bool restore_loglevel = true;

1681

if(ret_linux == -1){

1682

restore_loglevel = false;

1683

perror_plus("klogctl");

2295

1684

}

2296

1685

#endif /* __linux__ */

2297

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

2298

ioctl_errno = errno;

1686

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

1687

ret_errno = errno;

2299

1688

#ifdef __linux__

2300

1689

if(restore_loglevel){

2301

1690

ret_linux = klogctl(7, NULL, 0);

2305

1694

}

2306

1695

#endif /* __linux__ */

2307

1696

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

}

1697

/* Lower privileges */

1698

lower_privileges();

2317

1699

2318

1700

/* Close the socket */

2319

ret = close(sd);

1701

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

2320

1702

if(ret == -1){

2321

1703

perror_plus("close");

2322

1704

}

2323

1705

2324

1706

if(ret_setflags == -1){

2325

errno = ioctl_errno;

1707

errno = ret_errno;

2326

1708

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2327

1709

errno = old_errno;

2328

return ioctl_errno;

1710

return ret_errno;

2329

1711

}

2330

1712

} else if(debug){

2331

1713

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

2334

1716

2335

1717

/* Sleep checking until interface is running.

2336

1718

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

2337

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

1719

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

2338

1720

if(interface_is_running(interface)){

2339

1721

break;

2340

1722

}

2349

1731

return 0;

2350

1732

}

2351

1733

2352

__attribute__((nonnull, warn_unused_result))

2353

int take_down_interface(const char *const interface){

2354

int old_errno = errno;

1734

error_t take_down_interface(const char *const interface){

1735

error_t old_errno = errno;

2355

1736

struct ifreq network;

2356

1737

unsigned int if_index = if_nametoindex(interface);

2357

1738

if(if_index == 0){

2360

1741

return ENXIO;

2361

1742

}

2362

1743

if(interface_is_up(interface)){

2363

int ret_errno = 0;

2364

int ioctl_errno = 0;

1744

error_t ret_errno = 0;

2365

1745

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

2366

1746

ret_errno = errno;

2367

1747

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

2368

1748

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

2369

errno = old_errno;

2370

1749

return ret_errno;

2371

1750

}

2372

1751

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

2373

1752

2374

1753

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

2375

if(sd == -1){

1754

if(sd < 0){

2376

1755

ret_errno = errno;

2377

1756

perror_plus("socket");

2378

1757

errno = old_errno;

2384

1763

interface);

2385

1764

}

2386

1765

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

}

1766

/* Raise priviliges */

1767

raise_privileges();

2393

1768

2394

1769

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

2395

ioctl_errno = errno;

1770

ret_errno = errno;

2396

1771

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

}

1772

/* Lower privileges */

1773

lower_privileges();

2406

1774

2407

1775

/* Close the socket */

2408

int ret = close(sd);

1776

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

2409

1777

if(ret == -1){

2410

1778

perror_plus("close");

2411

1779

}

2412

1780

2413

1781

if(ret_setflags == -1){

2414

errno = ioctl_errno;

1782

errno = ret_errno;

2415

1783

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2416

1784

errno = old_errno;

2417

return ioctl_errno;

1785

return ret_errno;

2418

1786

}

2419

1787

} else if(debug){

2420

1788

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

2426

1794

}

2427

1795

2428

1796

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

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 };

1797

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

1798

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

1799

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

1800

.interfaces = NULL, .interfaces_size = 0 };

2434

1801

AvahiSServiceBrowser *sb = NULL;

2435

1802

error_t ret_errno;

2436

1803

int ret;

2439

1806

int exitcode = EXIT_SUCCESS;

2440

1807

char *interfaces_to_take_down = NULL;

2441

1808

size_t interfaces_to_take_down_size = 0;

2442

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

2443

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

2444

char *tempdir = NULL;

1809

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

1810

bool tempdir_created = false;

2445

1811

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2446

1812

const char *seckey = PATHDIR "/" SECKEY;

2447

1813

const char *pubkey = PATHDIR "/" PUBKEY;

2448

const char *dh_params_file = NULL;

2449

1814

char *interfaces_hooks = NULL;

2450

1815

2451

1816

bool gnutls_initialized = false;

2504

1869

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

2505

1870

" Diffie-Hellman key exchange",

2506

1871

.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 },

2512

1872

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

2513

1873

.arg = "STRING",

2514

1874

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

2569

1929

}

2570

1930

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

2571

1931

break;

2572

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

2573

dh_params_file = arg;

2574

break;

2575

1932

case 130: /* --priority */

2576

1933

mc.priority = arg;

2577

1934

break;

2617

1974

.args_doc = "",

2618

1975

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

2619

1976

" passwords from a Mandos server" };

2620

ret_errno = argp_parse(&argp, argc, argv,

2621

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2622

switch(ret_errno){

1977

ret = argp_parse(&argp, argc, argv,

1978

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1979

switch(ret){

2623

1980

case 0:

2624

1981

break;

2625

1982

case ENOMEM:

2626

1983

default:

2627

errno = ret_errno;

1984

errno = ret;

2628

1985

perror_plus("argp_parse");

2629

1986

exitcode = EX_OSERR;

2630

1987

goto end;

2633

1990

goto end;

2634

1991

}

2635

1992

}

2636

1993

2637

1994

{

2638

1995

/* Work around Debian bug #633582:

2639

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

1996

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

2640

1997

2641

/* Re-raise privileges */

2642

ret = raise_privileges();

2643

if(ret != 0){

2644

errno = ret;

2645

perror_plus("Failed to raise privileges");

2646

} else {

1998

/* Re-raise priviliges */

1999

if(raise_privileges() == 0){

2647

2000

struct stat st;

2648

2001

2649

2002

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

2663

2016

}

2664

2017

}

2665

2018

}

2666

close(seckey_fd);

2019

TEMP_FAILURE_RETRY(close(seckey_fd));

2667

2020

}

2668

2021

}

2669

2022

2670

2023

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

2671

2024

int pubkey_fd = open(pubkey, O_RDONLY);

2672

2025

if(pubkey_fd == -1){

2684

2037

}

2685

2038

}

2686

2039

}

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

2040

TEMP_FAILURE_RETRY(close(pubkey_fd));

2041

}

2042

}

2043

2713

2044

/* Lower privileges */

2714

ret = lower_privileges();

2715

if(ret != 0){

2716

errno = ret;

2717

perror_plus("Failed to lower privileges");

2718

}

2045

lower_privileges();

2719

2046

}

2720

2047

}

2721

2048

2747

2074

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

2748

2075

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

2749

2076

}

2750

run_network_hooks("start", interfaces_hooks != NULL ?

2751

interfaces_hooks : "", delay);

2077

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

2078

interfaces_hooks : "", delay)){

2079

goto end;

2080

}

2752

2081

}

2753

2082

2754

2083

if(not debug){

2832

2161

2833

2162

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

2834

2163

if(mc.interfaces == NULL){

2835

struct dirent **direntries = NULL;

2164

struct dirent **direntries;

2836

2165

/* Look for any good interfaces */

2837

2166

ret = scandir(sys_class_net, &direntries, good_interface,

2838

2167

alphasort);

2844

2173

if(ret_errno != 0){

2845

2174

errno = ret_errno;

2846

2175

perror_plus("argz_add");

2847

free(direntries[i]);

2848

2176

continue;

2849

2177

}

2850

2178

if(debug){

2851

2179

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

2852

2180

direntries[i]->d_name);

2853

2181

}

2854

free(direntries[i]);

2855

2182

}

2856

2183

free(direntries);

2857

2184

} else {

2858

if(ret == 0){

2859

free(direntries);

2860

}

2185

free(direntries);

2861

2186

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

2862

2187

exitcode = EXIT_FAILURE;

2863

2188

goto end;

2886

2211

break;

2887

2212

}

2888

2213

bool interface_was_up = interface_is_up(interface);

2889

errno = bring_up_interface(interface, delay);

2214

ret = bring_up_interface(interface, delay);

2890

2215

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));

2216

if(ret != 0){

2217

errno = ret;

2218

perror_plus("Failed to bring up interface");

2894

2219

} else {

2895

errno = argz_add(&interfaces_to_take_down,

2896

&interfaces_to_take_down_size,

2897

interface);

2898

if(errno != 0){

2220

ret_errno = argz_add(&interfaces_to_take_down,

2221

&interfaces_to_take_down_size,

2222

interface);

2223

if(ret_errno != 0){

2224

errno = ret_errno;

2899

2225

perror_plus("argz_add");

2900

2226

}

2901

2227

}

2919

2245

goto end;

2920

2246

}

2921

2247

2922

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

2248

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

2923

2249

if(ret == -1){

2924

2250

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

2925

2251

exitcode = EX_UNAVAILABLE;

2932

2258

goto end;

2933

2259

}

2934

2260

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){

2261

if(mkdtemp(tempdir) == NULL){

2945

2262

perror_plus("mkdtemp");

2946

2263

goto end;

2947

2264

}

2265

tempdir_created = true;

2948

2266

2949

2267

if(quit_now){

2950

2268

goto end;

3025

2343

sleep((unsigned int)retry_interval);

3026

2344

}

3027

2345

3028

if(not quit_now){

2346

if (not quit_now){

3029

2347

exitcode = EXIT_SUCCESS;

3030

2348

}

3031

2349

3047

2365

3048

2366

/* Allocate a new server */

3049

2367

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3050

&config, NULL, NULL, &ret);

2368

&config, NULL, NULL, &ret_errno);

3051

2369

3052

2370

/* Free the Avahi configuration data */

3053

2371

avahi_server_config_free(&config);

3056

2374

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

3057

2375

if(mc.server == NULL){

3058

2376

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

3059

avahi_strerror(ret));

2377

avahi_strerror(ret_errno));

3060

2378

exitcode = EX_UNAVAILABLE;

3061

2379

goto end;

3062

2380

}

3086

2404

if(debug){

3087

2405

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

3088

2406

}

3089

2407

3090

2408

ret = avahi_loop_with_timeout(simple_poll,

3091

2409

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

3092

2410

if(debug){

3097

2415

end:

3098

2416

3099

2417

if(debug){

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

}

2418

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

3107

2419

}

3108

2420

3109

2421

/* Cleanup things */

3120

2432

3121

2433

if(gnutls_initialized){

3122

2434

gnutls_certificate_free_credentials(mc.cred);

2435

gnutls_global_deinit();

3123

2436

gnutls_dh_params_deinit(mc.dh_params);

3124

2437

}

3125

2438

3133

2446

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

3134

2447

while(mc.current_server != NULL){

3135

2448

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

3144

2449

free(mc.current_server);

3145

2450

mc.current_server = next;

3146

2451

}

3147

2452

}

3148

2453

3149

/* Re-raise privileges */

2454

/* Re-raise priviliges */

3150

2455

{

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

}

2456

raise_privileges();

2457

2458

/* Run network hooks */

2459

run_network_hooks("stop", interfaces_hooks != NULL ?

2460

interfaces_hooks : "", delay);

2461

2462

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

2463

{

2464

char *interface = NULL;

2465

while((interface=argz_next(interfaces_to_take_down,

2466

interfaces_to_take_down_size,

2467

interface))){

2468

ret_errno = take_down_interface(interface);

2469

if(ret_errno != 0){

2470

errno = ret_errno;

2471

perror_plus("Failed to take down interface");

2472

}

2473

}

2474

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

2475

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

2476

" down\n");

2477

}

2478

}

2479

2480

lower_privileges_permanently();

3185

2481

}

3186

2482

3187

2483

free(interfaces_to_take_down);

3188

2484

free(interfaces_hooks);

3189

2485

3190

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

3191

uintmax_t level){

2486

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

2487

if(tempdir_created){

3192

2488

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){

2489

struct dirent *direntry = NULL;

2490

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

2491

alphasort);

2492

if (numentries > 0){

3206

2493

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

3244

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

3245

if(tempdir != NULL){

3246

clean_dir_at(-1, tempdir, 0);

2494

direntry = direntries[i];

2495

char *fullname = NULL;

2496

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

2497

direntry->d_name);

2498

if(ret < 0){

2499

perror_plus("asprintf");

2500

continue;

2501

}

2502

ret = remove(fullname);

2503

if(ret == -1){

2504

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

2505

strerror(errno));

2506

}

2507

free(fullname);

2508

}

2509

}

2510

2511

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

2512

free(direntries);

2513

if (numentries == -1){

2514

perror_plus("scandir");

2515

}

2516

ret = rmdir(tempdir);

2517

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

2518

perror_plus("rmdir");

2519

}

3247

2520

}

3248

2521

3249

2522

if(quit_now){