/mandos/trunk : revision 955

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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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195

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){

213

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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229

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

241

if(new_server->ip == NULL){

224

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perror_plus("strdup");

243

free(new_server);

244

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

263

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;

237

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(*current_server)->prev = new_server;

238

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.

249

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;

267

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

665

1206

bool match = false;

666

1207

{

667

1208

char *interface = NULL;

668

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

669

interface))){

1209

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

1210

mc->interfaces_size,

1211

interface))){

670

1212

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

671

1213

match = true;

672

1214

break;

701

1243

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

702

1244

}

703

1245

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1246

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

705

1247

if(tcp_sd < 0){

706

1248

int e = errno;

707

1249

perror_plus("socket");

714

1256

goto mandos_end;

715

1257

}

716

1258

717

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

718

1259

if(af == AF_INET6){

719

to.in6.sin6_family = (sa_family_t)af;

720

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);

721

1263

} else { /* IPv4 */

722

to.in.sin_family = (sa_family_t)af;

723

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);

724

1267

}

725

1268

if(ret < 0 ){

726

1269

int e = errno;

735

1278

goto mandos_end;

736

1279

}

737

1280

if(af == AF_INET6){

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

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

741

-Wunreachable-code*/

1281

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

1282

if(IN6_IS_ADDR_LINKLOCAL

1283

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

742

1284

if(if_index == AVAHI_IF_UNSPEC){

743

1285

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

744

1286

" incomplete without a network interface\n");

746

1288

goto mandos_end;

747

1289

}

748

1290

/* Set the network interface number as scope */

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1291

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

750

1292

}

751

1293

} else {

752

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

753

-Wconversion and

754

-Wunreachable-code */

1294

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

755

1295

}

756

1296

757

1297

if(quit_now){

774

1314

}

775

1315

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

776

1316

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

777

const char *pcret;

778

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

781

} else {

782

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

783

sizeof(addrstr));

784

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

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

789

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

790

}

791

}

792

}

793

794

if(quit_now){

795

errno = EINTR;

796

goto mandos_end;

797

}

798

799

if(af == AF_INET6){

800

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

801

} else {

802

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

803

}

804

if(ret < 0){

805

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

806

int e = errno;

807

perror_plus("connect");

808

errno = e;

809

}

810

goto mandos_end;

811

}

812

813

if(quit_now){

814

errno = EINTR;

815

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;

816

1397

}

817

1398

818

1399

const char *out = mandos_protocol_version;

972

1553

&decrypted_buffer, mc);

973

1554

if(decrypted_buffer_size >= 0){

974

1555

1556

clearerr(stdout);

975

1557

written = 0;

976

1558

while(written < (size_t) decrypted_buffer_size){

977

1559

if(quit_now){

993

1575

}

994

1576

written += (size_t)ret;

995

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

}

996

1588

retval = 0;

997

1589

}

998

1590

}

1001

1593

1002

1594

mandos_end:

1003

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

}

1004

1602

int e = errno;

1005

1603

free(decrypted_buffer);

1006

1604

free(buffer);

1007

1605

if(tcp_sd >= 0){

1008

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

1606

ret = close(tcp_sd);

1009

1607

}

1010

1608

if(ret == -1){

1011

1609

if(e == 0){

1036

1634

AVAHI_GCC_UNUSED AvahiStringList *txt,

1037

1635

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1038

1636

flags,

1039

void* mc){

1637

void *mc){

1040

1638

if(r == NULL){

1041

1639

return;

1042

1640

}

1045

1643

timed out */

1046

1644

1047

1645

if(quit_now){

1646

avahi_s_service_resolver_free(r);

1048

1647

return;

1049

1648

}

1050

1649

1095

1694

const char *domain,

1096

1695

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1097

1696

flags,

1098

void* mc){

1697

void *mc){

1099

1698

if(b == NULL){

1100

1699

return;

1101

1700

}

1161

1760

errno = old_errno;

1162

1761

}

1163

1762

1763

__attribute__((nonnull, warn_unused_result))

1164

1764

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

1165

1765

int ret;

1166

error_t ret_errno;

1766

int old_errno;

1167

1767

1168

1768

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

1169

1769

if(s < 0){

1170

ret_errno = errno;

1770

old_errno = errno;

1171

1771

perror_plus("socket");

1172

errno = ret_errno;

1772

errno = old_errno;

1173

1773

return false;

1174

1774

}

1175

strcpy(ifr->ifr_name, ifname);

1775

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

1776

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

1176

1777

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1177

1778

if(ret == -1){

1178

1779

if(debug){

1179

ret_errno = errno;

1780

old_errno = errno;

1180

1781

perror_plus("ioctl SIOCGIFFLAGS");

1181

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;

1182

1788

}

1183

1789

return false;

1184

1790

}

1791

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

1792

old_errno = errno;

1793

perror_plus("close");

1794

errno = old_errno;

1795

}

1185

1796

return true;

1186

1797

}

1187

1798

1799

__attribute__((nonnull, warn_unused_result))

1188

1800

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

1189

1801

1190

1802

/* Reject the loopback device */

1232

1844

* corresponds to an acceptable network device.

1233

1845

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

1234

1846

*/

1847

__attribute__((nonnull, warn_unused_result))

1235

1848

int good_interface(const struct dirent *if_entry){

1236

1849

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

1237

1850

return 0;

1255

1868

/*

1256

1869

* This function determines if a network interface is up.

1257

1870

*/

1871

__attribute__((nonnull, warn_unused_result))

1258

1872

bool interface_is_up(const char *interface){

1259

1873

struct ifreq ifr;

1260

1874

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

1271

1885

/*

1272

1886

* This function determines if a network interface is running

1273

1887

*/

1888

__attribute__((nonnull, warn_unused_result))

1274

1889

bool interface_is_running(const char *interface){

1275

1890

struct ifreq ifr;

1276

1891

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

1284

1899

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

1285

1900

}

1286

1901

1902

__attribute__((nonnull, pure, warn_unused_result))

1287

1903

int notdotentries(const struct dirent *direntry){

1288

1904

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

1289

1905

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

1296

1912

}

1297

1913

1298

1914

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

1915

__attribute__((nonnull, warn_unused_result))

1299

1916

int runnable_hook(const struct dirent *direntry){

1300

1917

int ret;

1301

1918

size_t sret;

1309

1926

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

1310

1927

"abcdefghijklmnopqrstuvwxyz"

1311

1928

"0123456789"

1312

"_-");

1929

"_.-");

1313

1930

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

1314

1931

/* Contains non-allowed characters */

1315

1932

if(debug){

1319

1936

return 0;

1320

1937

}

1321

1938

1322

char *fullname = NULL;

1323

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

1324

if(ret < 0){

1325

perror_plus("asprintf");

1326

return 0;

1327

}

1328

1329

ret = stat(fullname, &st);

1939

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

1330

1940

if(ret == -1){

1331

1941

if(debug){

1332

1942

perror_plus("Could not stat hook");

1356

1966

return 1;

1357

1967

}

1358

1968

1969

__attribute__((nonnull, warn_unused_result))

1359

1970

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1360

1971

mandos_context *mc){

1361

1972

int ret;

1365

1976

1366

1977

while(true){

1367

1978

if(mc->current_server == NULL){

1368

if (debug){

1979

if(debug){

1369

1980

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

1370

1981

" No timeout!\n");

1371

1982

}

1372

1983

ret = avahi_simple_poll_iterate(s, -1);

1373

1984

} else {

1374

if (debug){

1985

if(debug){

1375

1986

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

1376

1987

" it, or wait\n");

1377

1988

}

1394

2005

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

1395

2006

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

1396

2007

1397

if (debug){

2008

if(debug){

1398

2009

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

1399

2010

block_time);

1400

2011

}

1422

2033

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

1423

2034

}

1424

2035

if(ret != 0){

1425

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

2036

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

1426

2037

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

1427

2038

}

1428

2039

}

1429

2040

}

1430

2041

}

1431

2042

1432

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

1433

error_t raise_privileges(void){

1434

error_t old_errno = errno;

1435

error_t ret_errno = 0;

1436

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

1437

ret_errno = errno;

1438

perror_plus("seteuid");

1439

}

1440

errno = old_errno;

1441

return ret_errno;

1442

}

1443

1444

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

1445

error_t raise_privileges_permanently(void){

1446

error_t old_errno = errno;

1447

error_t ret_errno = raise_privileges();

1448

if(ret_errno != 0){

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

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

1453

ret_errno = errno;

1454

perror_plus("seteuid");

1455

}

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

1460

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

1461

error_t lower_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

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

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

/* Lower privileges permanently */

1473

error_t lower_privileges_permanently(void){

1474

error_t old_errno = errno;

1475

error_t ret_errno = 0;

1476

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

1477

ret_errno = errno;

1478

perror_plus("setuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

2043

__attribute__((nonnull))

2044

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

1485

2045

const float delay){

1486

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

}

1487

2074

struct dirent *direntry;

1488

2075

int ret;

1489

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

1490

alphasort);

1491

if(numhooks == -1){

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

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);

1499

2081

}

1500

} else {

1501

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

1502

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

1503

direntry = direntries[i];

1504

char *fullname = NULL;

1505

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

1506

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){

1507

2128

perror_plus("asprintf");

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

2129

_exit(EX_OSERR);

2130

}

2131

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

2132

if(ret == -1){

1566

2133

free(delaystring);

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

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

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

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;

1578

2202

} else {

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

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);

1615

2222

}

1616

2223

1617

error_t bring_up_interface(const char *const interface,

1618

const float delay){

1619

int sd = -1;

1620

error_t old_errno = errno;

1621

error_t ret_errno = 0;

1622

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;

1623

2229

struct ifreq network;

1624

2230

unsigned int if_index = if_nametoindex(interface);

1625

2231

if(if_index == 0){

1634

2240

}

1635

2241

1636

2242

if(not interface_is_up(interface)){

1637

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)){

1638

2246

ret_errno = errno;

1639

2247

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

1640

2248

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

2249

errno = old_errno;

1641

2250

return ret_errno;

1642

2251

}

1643

network.ifr_flags |= IFF_UP;

2252

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

1644

2253

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2254

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

2255

if(sd == -1){

1647

2256

ret_errno = errno;

1648

2257

perror_plus("socket");

1649

2258

errno = old_errno;

1650

2259

return ret_errno;

1651

2260

}

1652

2261

1653

2262

if(quit_now){

1654

close(sd);

2263

ret = close(sd);

2264

if(ret == -1){

2265

perror_plus("close");

2266

}

1655

2267

errno = old_errno;

1656

2268

return EINTR;

1657

2269

}

1661

2273

interface);

1662

2274

}

1663

2275

1664

/* Raise priviliges */

1665

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

}

1666

2282

1667

2283

#ifdef __linux__

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

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

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

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

}

1675

2295

}

1676

2296

#endif /* __linux__ */

1677

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

1678

ret_errno = errno;

2297

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

2298

ioctl_errno = errno;

1679

2299

#ifdef __linux__

1680

2300

if(restore_loglevel){

1681

2301

ret_linux = klogctl(7, NULL, 0);

1685

2305

}

1686

2306

#endif /* __linux__ */

1687

2307

1688

/* Lower privileges */

1689

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

}

1690

2317

1691

2318

/* Close the socket */

1692

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

2319

ret = close(sd);

1693

2320

if(ret == -1){

1694

2321

perror_plus("close");

1695

2322

}

1696

2323

1697

2324

if(ret_setflags == -1){

1698

errno = ret_errno;

2325

errno = ioctl_errno;

1699

2326

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1700

2327

errno = old_errno;

1701

return ret_errno;

2328

return ioctl_errno;

1702

2329

}

1703

2330

} else if(debug){

1704

2331

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

1707

2334

1708

2335

/* Sleep checking until interface is running.

1709

2336

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

1710

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

2337

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

1711

2338

if(interface_is_running(interface)){

1712

2339

break;

1713

2340

}

1722

2349

return 0;

1723

2350

}

1724

2351

1725

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

1727

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

2352

__attribute__((nonnull, warn_unused_result))

2353

int take_down_interface(const char *const interface){

2354

int old_errno = errno;

1730

2355

struct ifreq network;

1731

2356

unsigned int if_index = if_nametoindex(interface);

1732

2357

if(if_index == 0){

1735

2360

return ENXIO;

1736

2361

}

1737

2362

if(interface_is_up(interface)){

2363

int ret_errno = 0;

2364

int ioctl_errno = 0;

1738

2365

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

1739

2366

ret_errno = errno;

1740

2367

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

1741

2368

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

2369

errno = old_errno;

1742

2370

return ret_errno;

1743

2371

}

1744

2372

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

1745

2373

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2374

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

2375

if(sd == -1){

1748

2376

ret_errno = errno;

1749

2377

perror_plus("socket");

1750

2378

errno = old_errno;

1756

2384

interface);

1757

2385

}

1758

2386

1759

/* Raise priviliges */

1760

raise_privileges();

1761

1762

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

1763

ret_errno = errno;

1764

1765

/* Lower privileges */

1766

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

}

1767

2406

1768

2407

/* Close the socket */

1769

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

2408

int ret = close(sd);

1770

2409

if(ret == -1){

1771

2410

perror_plus("close");

1772

2411

}

1773

2412

1774

2413

if(ret_setflags == -1){

1775

errno = ret_errno;

2414

errno = ioctl_errno;

1776

2415

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1777

2416

errno = old_errno;

1778

return ret_errno;

2417

return ioctl_errno;

1779

2418

}

1780

2419

} else if(debug){

1781

2420

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

1787

2426

}

1788

2427

1789

2428

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

1790

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

1791

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

1792

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

1793

.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 };

1794

2434

AvahiSServiceBrowser *sb = NULL;

1795

2435

error_t ret_errno;

1796

2436

int ret;

1799

2439

int exitcode = EXIT_SUCCESS;

1800

2440

char *interfaces_to_take_down = NULL;

1801

2441

size_t interfaces_to_take_down_size = 0;

1802

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

1803

bool tempdir_created = false;

2442

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

2443

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

2444

char *tempdir = NULL;

1804

2445

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1805

2446

const char *seckey = PATHDIR "/" SECKEY;

1806

2447

const char *pubkey = PATHDIR "/" PUBKEY;

2448

const char *dh_params_file = NULL;

1807

2449

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

1809

2450

1810

2451

bool gnutls_initialized = false;

1811

2452

bool gpgme_initialized = false;

1863

2504

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

1864

2505

" Diffie-Hellman key exchange",

1865

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 },

1866

2512

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

1867

2513

.arg = "STRING",

1868

2514

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

1923

2569

}

1924

2570

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

1925

2571

break;

2572

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

2573

dh_params_file = arg;

2574

break;

1926

2575

case 130: /* --priority */

1927

2576

mc.priority = arg;

1928

2577

break;

1968

2617

.args_doc = "",

1969

2618

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

1970

2619

" passwords from a Mandos server" };

1971

ret = argp_parse(&argp, argc, argv,

1972

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1973

switch(ret){

2620

ret_errno = argp_parse(&argp, argc, argv,

2621

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2622

switch(ret_errno){

1974

2623

case 0:

1975

2624

break;

1976

2625

case ENOMEM:

1977

2626

default:

1978

errno = ret;

2627

errno = ret_errno;

1979

2628

perror_plus("argp_parse");

1980

2629

exitcode = EX_OSERR;

1981

2630

goto end;

1984

2633

goto end;

1985

2634

}

1986

2635

}

1987

2636

1988

2637

{

1989

2638

/* Work around Debian bug #633582:

1990

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

2639

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

1991

2640

1992

/* Re-raise priviliges */

1993

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 {

1994

2647

struct stat st;

1995

2648

1996

2649

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

2010

2663

}

2011

2664

}

2012

2665

}

2013

TEMP_FAILURE_RETRY(close(seckey_fd));

2666

close(seckey_fd);

2014

2667

}

2015

2668

}

2016

2669

2017

2670

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

2018

2671

int pubkey_fd = open(pubkey, O_RDONLY);

2019

2672

if(pubkey_fd == -1){

2031

2684

}

2032

2685

}

2033

2686

}

2034

TEMP_FAILURE_RETRY(close(pubkey_fd));

2035

}

2036

}

2037

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

2038

2713

/* Lower privileges */

2039

lower_privileges();

2714

ret = lower_privileges();

2715

if(ret != 0){

2716

errno = ret;

2717

perror_plus("Failed to lower privileges");

2718

}

2040

2719

}

2041

2720

}

2042

2721

2066

2745

goto end;

2067

2746

}

2068

2747

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

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

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

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2748

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

2749

}

2750

run_network_hooks("start", interfaces_hooks != NULL ?

2751

interfaces_hooks : "", delay);

2077

2752

}

2078

2753

2079

2754

if(not debug){

2157

2832

2158

2833

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

2159

2834

if(mc.interfaces == NULL){

2160

struct dirent **direntries;

2835

struct dirent **direntries = NULL;

2161

2836

/* Look for any good interfaces */

2162

2837

ret = scandir(sys_class_net, &direntries, good_interface,

2163

2838

alphasort);

2167

2842

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

2168

2843

direntries[i]->d_name);

2169

2844

if(ret_errno != 0){

2845

errno = ret_errno;

2170

2846

perror_plus("argz_add");

2847

free(direntries[i]);

2171

2848

continue;

2172

2849

}

2173

2850

if(debug){

2174

2851

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

2175

2852

direntries[i]->d_name);

2176

2853

}

2854

free(direntries[i]);

2177

2855

}

2178

2856

free(direntries);

2179

2857

} else {

2180

free(direntries);

2858

if(ret == 0){

2859

free(direntries);

2860

}

2181

2861

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

2182

2862

exitcode = EXIT_FAILURE;

2183

2863

goto end;

2206

2886

break;

2207

2887

}

2208

2888

bool interface_was_up = interface_is_up(interface);

2209

ret = bring_up_interface(interface, delay);

2889

errno = bring_up_interface(interface, delay);

2210

2890

if(not interface_was_up){

2211

if(ret != 0){

2212

errno = ret;

2213

perror_plus("Failed to bring up interface");

2891

if(errno != 0){

2892

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

2893

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

2214

2894

} else {

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

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

}

2218

2901

}

2219

2902

}

2220

2903

}

2236

2919

goto end;

2237

2920

}

2238

2921

2239

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

2922

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

2240

2923

if(ret == -1){

2241

2924

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

2242

2925

exitcode = EX_UNAVAILABLE;

2249

2932

goto end;

2250

2933

}

2251

2934

2252

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){

2253

2945

perror_plus("mkdtemp");

2254

2946

goto end;

2255

2947

}

2256

tempdir_created = true;

2257

2948

2258

2949

if(quit_now){

2259

2950

goto end;

2331

3022

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

2332

3023

(int)retry_interval);

2333

3024

}

2334

sleep((int)retry_interval);

3025

sleep((unsigned int)retry_interval);

2335

3026

}

2336

3027

2337

if (not quit_now){

3028

if(not quit_now){

2338

3029

exitcode = EXIT_SUCCESS;

2339

3030

}

2340

3031

2356

3047

2357

3048

/* Allocate a new server */

2358

3049

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2359

&config, NULL, NULL, &ret_errno);

3050

&config, NULL, NULL, &ret);

2360

3051

2361

3052

/* Free the Avahi configuration data */

2362

3053

avahi_server_config_free(&config);

2365

3056

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

2366

3057

if(mc.server == NULL){

2367

3058

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

2368

avahi_strerror(ret_errno));

3059

avahi_strerror(ret));

2369

3060

exitcode = EX_UNAVAILABLE;

2370

3061

goto end;

2371

3062

}

2395

3086

if(debug){

2396

3087

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

2397

3088

}

2398

3089

2399

3090

ret = avahi_loop_with_timeout(simple_poll,

2400

3091

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

2401

3092

if(debug){

2406

3097

end:

2407

3098

2408

3099

if(debug){

2409

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

}

2410

3107

}

2411

3108

2412

3109

/* Cleanup things */

2423

3120

2424

3121

if(gnutls_initialized){

2425

3122

gnutls_certificate_free_credentials(mc.cred);

2426

gnutls_global_deinit();

2427

3123

gnutls_dh_params_deinit(mc.dh_params);

2428

3124

}

2429

3125

2437

3133

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

2438

3134

while(mc.current_server != NULL){

2439

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

2440

3144

free(mc.current_server);

2441

3145

mc.current_server = next;

2442

3146

}

2443

3147

}

2444

3148

2445

/* Re-raise priviliges */

3149

/* Re-raise privileges */

2446

3150

{

2447

raise_privileges();

2448

2449

/* Run network hooks */

2450

run_network_hooks("stop", interfaces_hooks != NULL ?

2451

interfaces_hooks : "", delay);

2452

2453

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

2454

{

2455

char *interface = NULL;

2456

while((interface=argz_next(interfaces_to_take_down,

2457

interfaces_to_take_down_size,

2458

interface))){

2459

ret_errno = take_down_interface(interface);

2460

if(ret_errno != 0){

2461

errno = ret_errno;

2462

perror_plus("Failed to take down interface");

2463

}

2464

}

2465

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

2466

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

2467

" down\n");

2468

}

2469

}

2470

2471

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

}

2472

3185

}

2473

3186

2474

3187

free(interfaces_to_take_down);

2475

3188

free(interfaces_hooks);

2476

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

2477

3244

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

2478

if(tempdir_created){

2479

struct dirent **direntries = NULL;

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

2484

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

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

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

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

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

2496

strerror(errno));

2497

}

2498

free(fullname);

2499

}

2500

}

2501

2502

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

2503

free(direntries);

2504

if (numentries == -1){

2505

perror_plus("scandir");

2506

}

2507

ret = rmdir(tempdir);

2508

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

2509

perror_plus("rmdir");

2510

}

3245

if(tempdir != NULL){

3246

clean_dir_at(-1, tempdir, 0);

2511

3247

}

2512

3248

2513

3249

if(quit_now){