/mandos/release : revision 237.7.149

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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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21

* 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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30

*/

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32

/* 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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53

sockaddr_in6, PF_INET6,

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55

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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62

#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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66

#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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73

#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() */

75

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

76

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

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

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78

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

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79

argp_state, struct argp,

99

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

102

#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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96

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

148

138

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

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139

char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

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141

uid_t uid = 65534;

153

142

gid_t gid = 65534;

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143

172

161

const char *priority;

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162

gpgme_ctx_t ctx;

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server *current_server;

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char *interfaces;

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size_t interfaces_size;

177

164

} mandos_context;

178

165

179

166

/* global so signal handler can reach it*/

180

167

AvahiSimplePoll *simple_poll;

168

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

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

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

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182

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sig_atomic_t quit_now = 0;

183

173

int signal_received = 0;

191

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perror(print_text);

192

182

}

193

183

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

184

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

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185

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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188

199

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

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program_invocation_short_name));

201

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

191

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

202

192

}

203

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/*

206

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

207

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* "buffer_length" is how much is already used.

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198

*/

209

__attribute__((nonnull, warn_unused_result))

210

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size_t incbuffer(char **buffer, size_t buffer_length,

211

200

size_t buffer_capacity){

212

201

if(buffer_length + BUFFER_SIZE > buffer_capacity){

213

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

214

if(new_buf == NULL){

215

int old_errno = errno;

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free(*buffer);

217

errno = old_errno;

218

*buffer = NULL;

202

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

203

if(buffer == NULL){

219

204

return 0;

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205

}

221

*buffer = new_buf;

222

206

buffer_capacity += BUFFER_SIZE;

223

207

}

224

208

return buffer_capacity;

225

209

}

226

210

227

211

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

228

__attribute__((nonnull, warn_unused_result))

229

212

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

230

int af, server **current_server){

213

int af){

231

214

int ret;

232

215

server *new_server = malloc(sizeof(server));

233

216

if(new_server == NULL){

240

223

.af = af };

241

224

if(new_server->ip == NULL){

242

225

perror_plus("strdup");

243

free(new_server);

244

return false;

245

}

246

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);

258

226

return false;

259

227

}

260

228

/* Special case of first server */

261

if(*current_server == NULL){

229

if (mc.current_server == NULL){

262

230

new_server->next = new_server;

263

231

new_server->prev = new_server;

264

*current_server = new_server;

232

mc.current_server = new_server;

233

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

265

234

} else {

266

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

267

new_server->next = *current_server;

268

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

235

new_server->next = mc.current_server;

236

new_server->prev = mc.current_server->prev;

269

237

new_server->prev->next = new_server;

270

(*current_server)->prev = new_server;

238

mc.current_server->prev = new_server;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

return false;

271

244

}

272

245

return true;

273

246

}

275

248

/*

276

249

* Initialize GPGME.

277

250

*/

278

__attribute__((nonnull, warn_unused_result))

279

static bool init_gpgme(const char * const seckey,

280

const char * const pubkey,

281

const char * const tempdir,

282

mandos_context *mc){

251

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

252

const char *tempdir){

283

253

gpgme_error_t rc;

284

254

gpgme_engine_info_t engine_info;

285

255

286

256

/*

287

257

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

288

258

*/

289

bool import_key(const char * const filename){

259

bool import_key(const char *filename){

290

260

int ret;

291

261

int fd;

292

262

gpgme_data_t pgp_data;

304

274

return false;

305

275

}

306

276

307

rc = gpgme_op_import(mc->ctx, pgp_data);

277

rc = gpgme_op_import(mc.ctx, pgp_data);

308

278

if(rc != GPG_ERR_NO_ERROR){

309

279

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

310

280

gpgme_strsource(rc), gpgme_strerror(rc));

311

281

return false;

312

282

}

313

283

314

ret = close(fd);

284

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

315

285

if(ret == -1){

316

286

perror_plus("close");

317

287

}

354

324

}

355

325

356

326

/* Create new GPGME "context" */

357

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

327

rc = gpgme_new(&(mc.ctx));

358

328

if(rc != GPG_ERR_NO_ERROR){

359

329

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

360

330

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

373

343

* Decrypt OpenPGP data.

374

344

* Returns -1 on error

375

345

*/

376

__attribute__((nonnull, warn_unused_result))

377

346

static ssize_t pgp_packet_decrypt(const char *cryptotext,

378

347

size_t crypto_size,

379

char **plaintext,

380

mandos_context *mc){

348

char **plaintext){

381

349

gpgme_data_t dh_crypto, dh_plain;

382

350

gpgme_error_t rc;

383

351

ssize_t ret;

409

377

410

378

/* Decrypt data from the cryptotext data buffer to the plaintext

411

379

data buffer */

412

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

380

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

413

381

if(rc != GPG_ERR_NO_ERROR){

414

382

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

415

383

gpgme_strsource(rc), gpgme_strerror(rc));

416

384

plaintext_length = -1;

417

385

if(debug){

418

386

gpgme_decrypt_result_t result;

419

result = gpgme_op_decrypt_result(mc->ctx);

387

result = gpgme_op_decrypt_result(mc.ctx);

420

388

if(result == NULL){

421

389

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

422

390

} else {

499

467

return plaintext_length;

500

468

}

501

469

502

__attribute__((warn_unused_result, const))

503

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

504

if(str == NULL)

505

return "(unknown)";

506

return str;

507

}

508

509

__attribute__((warn_unused_result))

510

static const char *safer_gnutls_strerror(int value){

470

static const char * safer_gnutls_strerror(int value){

511

471

const char *ret = gnutls_strerror(value);

512

return safe_string(ret);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

513

475

}

514

476

515

477

/* GnuTLS log function callback */

516

__attribute__((nonnull))

517

478

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

518

479

const char* string){

519

480

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

520

481

}

521

482

522

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

523

483

static int init_gnutls_global(const char *pubkeyfilename,

524

const char *seckeyfilename,

525

const char *dhparamsfilename,

526

mandos_context *mc){

484

const char *seckeyfilename){

527

485

int ret;

528

unsigned int uret;

529

486

530

487

if(debug){

531

488

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

532

489

}

533

490

491

ret = gnutls_global_init();

492

if(ret != GNUTLS_E_SUCCESS){

493

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

494

safer_gnutls_strerror(ret));

495

return -1;

496

}

497

534

498

if(debug){

535

499

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

536

500

* - GnuTLS manual

540

504

}

541

505

542

506

/* OpenPGP credentials */

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

507

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

508

if(ret != GNUTLS_E_SUCCESS){

545

509

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

546

510

safer_gnutls_strerror(ret));

511

gnutls_global_deinit();

547

512

return -1;

548

513

}

549

514

555

520

}

556

521

557

522

ret = gnutls_certificate_set_openpgp_key_file

558

(mc->cred, pubkeyfilename, seckeyfilename,

523

(mc.cred, pubkeyfilename, seckeyfilename,

559

524

GNUTLS_OPENPGP_FMT_BASE64);

560

525

if(ret != GNUTLS_E_SUCCESS){

561

526

fprintf_plus(stderr,

567

532

}

568

533

569

534

/* GnuTLS server initialization */

570

ret = gnutls_dh_params_init(&mc->dh_params);

535

ret = gnutls_dh_params_init(&mc.dh_params);

571

536

if(ret != GNUTLS_E_SUCCESS){

572

537

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

573

538

" initialization: %s\n",

574

539

safer_gnutls_strerror(ret));

575

540

goto globalfail;

576

541

}

577

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

578

if(dhparamsfilename != NULL){

579

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

580

do {

581

int dhpfile = open(dhparamsfilename, O_RDONLY);

582

if(dhpfile == -1){

583

perror_plus("open");

584

dhparamsfilename = NULL;

585

break;

586

}

587

size_t params_capacity = 0;

588

while(true){

589

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

590

(size_t)params.size,

591

(size_t)params_capacity);

592

if(params_capacity == 0){

593

perror_plus("incbuffer");

594

free(params.data);

595

params.data = NULL;

596

dhparamsfilename = NULL;

597

break;

598

}

599

ssize_t bytes_read = read(dhpfile,

600

params.data + params.size,

601

BUFFER_SIZE);

602

/* EOF */

603

if(bytes_read == 0){

604

break;

605

}

606

/* check bytes_read for failure */

607

if(bytes_read < 0){

608

perror_plus("read");

609

free(params.data);

610

params.data = NULL;

611

dhparamsfilename = NULL;

612

break;

613

}

614

params.size += (unsigned int)bytes_read;

615

}

616

if(params.data == NULL){

617

dhparamsfilename = NULL;

618

}

619

if(dhparamsfilename == NULL){

620

break;

621

}

622

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

623

GNUTLS_X509_FMT_PEM);

624

if(ret != GNUTLS_E_SUCCESS){

625

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

626

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

627

safer_gnutls_strerror(ret));

628

dhparamsfilename = NULL;

629

}

630

free(params.data);

631

} while(false);

632

}

633

if(dhparamsfilename == NULL){

634

if(mc->dh_bits == 0){

635

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

636

/* Try to read the private key file */

637

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

638

do {

639

int secfile = open(seckeyfilename, O_RDONLY);

640

if(secfile == -1){

641

perror_plus("open");

642

break;

643

}

644

size_t buffer_capacity = 0;

645

while(true){

646

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

647

(size_t)buffer.size,

648

(size_t)buffer_capacity);

649

if(buffer_capacity == 0){

650

perror_plus("incbuffer");

651

free(buffer.data);

652

buffer.data = NULL;

653

break;

654

}

655

ssize_t bytes_read = read(secfile,

656

buffer.data + buffer.size,

657

BUFFER_SIZE);

658

/* EOF */

659

if(bytes_read == 0){

660

break;

661

}

662

/* check bytes_read for failure */

663

if(bytes_read < 0){

664

perror_plus("read");

665

free(buffer.data);

666

buffer.data = NULL;

667

break;

668

}

669

buffer.size += (unsigned int)bytes_read;

670

}

671

close(secfile);

672

} while(false);

673

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

674

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

675

if(buffer.data != NULL){

676

{

677

gnutls_openpgp_privkey_t privkey = NULL;

678

ret = gnutls_openpgp_privkey_init(&privkey);

679

if(ret != GNUTLS_E_SUCCESS){

680

fprintf_plus(stderr, "Error initializing OpenPGP key"

681

" structure: %s",

682

safer_gnutls_strerror(ret));

683

free(buffer.data);

684

buffer.data = NULL;

685

} else {

686

ret = gnutls_openpgp_privkey_import

687

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

688

if(ret != GNUTLS_E_SUCCESS){

689

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

690

safer_gnutls_strerror(ret));

691

privkey = NULL;

692

}

693

free(buffer.data);

694

buffer.data = NULL;

695

if(privkey != NULL){

696

/* Use private key to suggest an appropriate

697

sec_param */

698

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

699

gnutls_openpgp_privkey_deinit(privkey);

700

if(debug){

701

fprintf_plus(stderr, "This OpenPGP key implies using"

702

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

703

safe_string(gnutls_sec_param_get_name

704

(sec_param)));

705

}

706

}

707

}

708

}

709

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

710

/* Err on the side of caution */

711

sec_param = GNUTLS_SEC_PARAM_ULTRA;

712

if(debug){

713

fprintf_plus(stderr, "Falling back to security parameter"

714

" \"%s\"\n",

715

safe_string(gnutls_sec_param_get_name

716

(sec_param)));

717

}

718

}

719

}

720

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

721

if(uret != 0){

722

mc->dh_bits = uret;

723

if(debug){

724

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

725

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

726

safe_string(gnutls_sec_param_get_name

727

(sec_param)),

728

mc->dh_bits);

729

}

730

} else {

731

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

732

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

733

safe_string(gnutls_sec_param_get_name

734

(sec_param)),

735

safer_gnutls_strerror(ret));

736

goto globalfail;

737

}

738

} else if(debug){

739

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

740

mc->dh_bits);

741

}

742

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

743

if(ret != GNUTLS_E_SUCCESS){

744

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

745

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

746

safer_gnutls_strerror(ret));

747

goto globalfail;

748

}

749

}

750

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

542

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

543

if(ret != GNUTLS_E_SUCCESS){

544

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

545

safer_gnutls_strerror(ret));

546

goto globalfail;

547

}

548

549

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

751

550

752

551

return 0;

753

552

754

553

globalfail:

755

554

756

gnutls_certificate_free_credentials(mc->cred);

757

gnutls_dh_params_deinit(mc->dh_params);

555

gnutls_certificate_free_credentials(mc.cred);

556

gnutls_global_deinit();

557

gnutls_dh_params_deinit(mc.dh_params);

758

558

return -1;

759

559

}

760

560

761

__attribute__((nonnull, warn_unused_result))

762

static int init_gnutls_session(gnutls_session_t *session,

763

mandos_context *mc){

561

static int init_gnutls_session(gnutls_session_t *session){

764

562

int ret;

765

563

/* GnuTLS session creation */

766

564

do {

778

576

{

779

577

const char *err;

780

578

do {

781

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

579

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

782

580

if(quit_now){

783

581

gnutls_deinit(*session);

784

582

return -1;

795

593

796

594

do {

797

595

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

798

mc->cred);

596

mc.cred);

799

597

if(quit_now){

800

598

gnutls_deinit(*session);

801

599

return -1;

811

609

/* ignore client certificate if any. */

812

610

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

813

611

612

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

613

814

614

return 0;

815

615

}

816

616

818

618

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

819

619

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

820

620

821

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

822

__attribute__((warn_unused_result))

823

int raise_privileges(void){

824

int old_errno = errno;

825

int ret = 0;

826

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

827

ret = errno;

828

}

829

errno = old_errno;

830

return ret;

831

}

832

833

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

834

__attribute__((warn_unused_result))

835

int raise_privileges_permanently(void){

836

int old_errno = errno;

837

int ret = raise_privileges();

838

if(ret != 0){

839

errno = old_errno;

840

return ret;

841

}

842

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

843

ret = errno;

844

}

845

errno = old_errno;

846

return ret;

847

}

848

849

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

850

__attribute__((warn_unused_result))

851

int lower_privileges(void){

852

int old_errno = errno;

853

int ret = 0;

854

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

855

ret = errno;

856

}

857

errno = old_errno;

858

return ret;

859

}

860

861

/* Lower privileges permanently */

862

__attribute__((warn_unused_result))

863

int lower_privileges_permanently(void){

864

int old_errno = errno;

865

int ret = 0;

866

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

867

ret = errno;

868

}

869

errno = old_errno;

870

return ret;

871

}

872

873

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

874

__attribute__((nonnull, warn_unused_result))

875

static bool add_delete_local_route(const bool add,

876

const char *address,

877

AvahiIfIndex if_index){

878

int ret;

879

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

880

char add_arg[] = "add";

881

char delete_arg[] = "delete";

882

char debug_flag[] = "--debug";

883

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

884

if(pluginhelperdir == NULL){

885

if(debug){

886

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

887

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

888

}

889

return false;

890

}

891

892

char interface[IF_NAMESIZE];

893

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

894

perror_plus("if_indextoname");

895

return false;

896

}

897

898

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

899

if(devnull == -1){

900

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

901

return false;

902

}

903

pid_t pid = fork();

904

if(pid == 0){

905

/* Child */

906

/* Raise privileges */

907

errno = raise_privileges_permanently();

908

if(errno != 0){

909

perror_plus("Failed to raise privileges");

910

/* _exit(EX_NOPERM); */

911

} else {

912

/* Set group */

913

errno = 0;

914

ret = setgid(0);

915

if(ret == -1){

916

perror_plus("setgid");

917

_exit(EX_NOPERM);

918

}

919

/* Reset supplementary groups */

920

errno = 0;

921

ret = setgroups(0, NULL);

922

if(ret == -1){

923

perror_plus("setgroups");

924

_exit(EX_NOPERM);

925

}

926

}

927

ret = dup2(devnull, STDIN_FILENO);

928

if(ret == -1){

929

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

930

_exit(EX_OSERR);

931

}

932

ret = close(devnull);

933

if(ret == -1){

934

perror_plus("close");

935

_exit(EX_OSERR);

936

}

937

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

938

if(ret == -1){

939

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

940

_exit(EX_OSERR);

941

}

942

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

943

O_RDONLY

944

| O_DIRECTORY

945

| O_PATH

946

| O_CLOEXEC));

947

if(helperdir_fd == -1){

948

perror_plus("open");

949

_exit(EX_UNAVAILABLE);

950

}

951

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

952

helper, O_RDONLY));

953

if(helper_fd == -1){

954

perror_plus("openat");

955

close(helperdir_fd);

956

_exit(EX_UNAVAILABLE);

957

}

958

close(helperdir_fd);

959

#ifdef __GNUC__

960

#pragma GCC diagnostic push

961

#pragma GCC diagnostic ignored "-Wcast-qual"

962

#endif

963

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

964

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

965

interface, debug ? debug_flag : NULL, NULL },

966

environ) == -1){

967

#ifdef __GNUC__

968

#pragma GCC diagnostic pop

969

#endif

970

perror_plus("fexecve");

971

_exit(EXIT_FAILURE);

972

}

973

}

974

if(pid == -1){

975

perror_plus("fork");

976

return false;

977

}

978

int status;

979

pid_t pret = -1;

980

errno = 0;

981

do {

982

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

983

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

984

int errno_raising = 0;

985

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

986

errno_raising = errno;

987

perror_plus("Failed to raise privileges in order to"

988

" kill helper program");

989

}

990

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

991

perror_plus("kill");

992

}

993

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

994

perror_plus("Failed to lower privileges after killing"

995

" helper program");

996

}

997

return false;

998

}

999

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

1000

if(pret == -1){

1001

perror_plus("waitpid");

1002

return false;

1003

}

1004

if(WIFEXITED(status)){

1005

if(WEXITSTATUS(status) != 0){

1006

fprintf_plus(stderr, "Error: iprouteadddel exited"

1007

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

1008

return false;

1009

}

1010

return true;

1011

}

1012

if(WIFSIGNALED(status)){

1013

fprintf_plus(stderr, "Error: iprouteadddel died by"

1014

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

1015

return false;

1016

}

1017

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

1018

return false;

1019

}

1020

1021

__attribute__((nonnull, warn_unused_result))

1022

static bool add_local_route(const char *address,

1023

AvahiIfIndex if_index){

1024

if(debug){

1025

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

1026

}

1027

return add_delete_local_route(true, address, if_index);

1028

}

1029

1030

__attribute__((nonnull, warn_unused_result))

1031

static bool delete_local_route(const char *address,

1032

AvahiIfIndex if_index){

1033

if(debug){

1034

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

1035

}

1036

return add_delete_local_route(false, address, if_index);

1037

}

1038

1039

621

/* Called when a Mandos server is found */

1040

__attribute__((nonnull, warn_unused_result))

1041

622

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

1042

623

AvahiIfIndex if_index,

1043

int af, mandos_context *mc){

624

int af){

1044

625

int ret, tcp_sd = -1;

1045

626

ssize_t sret;

1046

struct sockaddr_storage to;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

1047

631

char *buffer = NULL;

1048

632

char *decrypted_buffer = NULL;

1049

633

size_t buffer_length = 0;

1052

636

int retval = -1;

1053

637

gnutls_session_t session;

1054

638

int pf; /* Protocol family */

1055

bool route_added = false;

1056

639

1057

640

errno = 0;

1058

641

1074

657

return -1;

1075

658

}

1076

659

1077

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

1078

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

1079

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

1080

bool match = false;

1081

{

1082

char *interface = NULL;

1083

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

1084

mc->interfaces_size,

1085

interface))){

1086

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

1087

match = true;

1088

break;

1089

}

1090

}

1091

}

1092

if(not match){

1093

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

1094

connect to the server */

1095

if(debug){

1096

char interface[IF_NAMESIZE];

1097

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

1098

perror_plus("if_indextoname");

1099

} else {

1100

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

1101

" \"%s\"\n",

1102

if_indextoname((unsigned int)if_index,

1103

interface));

1104

}

1105

}

1106

return -1;

1107

}

1108

}

1109

1110

ret = init_gnutls_session(&session, mc);

660

ret = init_gnutls_session(&session);

1111

661

if(ret != 0){

1112

662

return -1;

1113

663

}

1117

667

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

1118

668

}

1119

669

1120

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

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

671

if(tcp_sd < 0){

1122

672

int e = errno;

1123

673

perror_plus("socket");

1130

680

goto mandos_end;

1131

681

}

1132

682

683

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

1133

684

if(af == AF_INET6){

1134

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

1135

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

1136

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

685

to.in6.sin6_family = (sa_family_t)af;

686

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

1137

687

} else { /* IPv4 */

1138

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

1139

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

1140

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

688

to.in.sin_family = (sa_family_t)af;

689

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

1141

690

}

1142

691

if(ret < 0 ){

1143

692

int e = errno;

1152

701

goto mandos_end;

1153

702

}

1154

703

if(af == AF_INET6){

1155

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

1156

if(IN6_IS_ADDR_LINKLOCAL

1157

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

704

to.in6.sin6_port = htons(port);

705

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

706

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

707

-Wunreachable-code*/

1158

708

if(if_index == AVAHI_IF_UNSPEC){

1159

709

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

1160

710

" incomplete without a network interface\n");

1162

712

goto mandos_end;

1163

713

}

1164

714

/* Set the network interface number as scope */

1165

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

715

to.in6.sin6_scope_id = (uint32_t)if_index;

1166

716

}

1167

717

} else {

1168

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

718

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

719

-Wconversion and

720

-Wunreachable-code */

1169

721

}

1170

722

1171

723

if(quit_now){

1188

740

}

1189

741

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1190

742

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1191

if(af == AF_INET6){

1192

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

1193

sizeof(struct sockaddr_in6),

1194

addrstr, sizeof(addrstr), NULL, 0,

1195

NI_NUMERICHOST);

1196

} else {

1197

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

1198

sizeof(struct sockaddr_in),

1199

addrstr, sizeof(addrstr), NULL, 0,

1200

NI_NUMERICHOST);

1201

}

1202

if(ret == EAI_SYSTEM){

1203

perror_plus("getnameinfo");

1204

} else if(ret != 0) {

1205

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

1206

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

1207

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

1208

}

1209

}

1210

1211

if(quit_now){

1212

errno = EINTR;

1213

goto mandos_end;

1214

}

1215

1216

while(true){

1217

if(af == AF_INET6){

1218

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

1219

sizeof(struct sockaddr_in6));

1220

} else {

1221

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

1222

sizeof(struct sockaddr_in));

1223

}

1224

if(ret < 0){

1225

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

1226

and if_index != AVAHI_IF_UNSPEC

1227

and connect_to == NULL

1228

and not route_added and

1229

((af == AF_INET6 and not

1230

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1231

&to)->sin6_addr)))

1232

or (af == AF_INET and

1233

/* Not a a IPv4LL address */

1234

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

1235

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

1236

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

1237

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

1238

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

1239

connect to a Mandos server announced by Avahi on a server

1240

host with a global address. Work around this by retrying

1241

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

1242

1243

Avahi bug reference:

1244

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

1245

https://bugs.debian.org/587961

1246

*/

1247

if(debug){

1248

fprintf_plus(stderr, "Mandos server unreachable, trying"

1249

" direct route\n");

1250

}

1251

int e = errno;

1252

route_added = add_local_route(ip, if_index);

1253

if(route_added){

1254

continue;

1255

}

1256

errno = e;

1257

}

1258

if(errno != ECONNREFUSED or debug){

1259

int e = errno;

1260

perror_plus("connect");

1261

errno = e;

1262

}

1263

goto mandos_end;

1264

}

1265

1266

if(quit_now){

1267

errno = EINTR;

1268

goto mandos_end;

1269

}

1270

break;

743

const char *pcret;

744

if(af == AF_INET6){

745

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

746

sizeof(addrstr));

747

} else {

748

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

749

sizeof(addrstr));

750

}

751

if(pcret == NULL){

752

perror_plus("inet_ntop");

753

} else {

754

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

755

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

756

}

757

}

758

}

759

760

if(quit_now){

761

errno = EINTR;

762

goto mandos_end;

763

}

764

765

if(af == AF_INET6){

766

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

767

} else {

768

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

769

}

770

if(ret < 0){

771

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

772

int e = errno;

773

perror_plus("connect");

774

errno = e;

775

}

776

goto mandos_end;

777

}

778

779

if(quit_now){

780

errno = EINTR;

781

goto mandos_end;

1271

782

}

1272

783

1273

784

const char *out = mandos_protocol_version;

1424

935

if(buffer_length > 0){

1425

936

ssize_t decrypted_buffer_size;

1426

937

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1427

&decrypted_buffer, mc);

938

&decrypted_buffer);

1428

939

if(decrypted_buffer_size >= 0){

1429

940

1430

clearerr(stdout);

1431

941

written = 0;

1432

942

while(written < (size_t) decrypted_buffer_size){

1433

943

if(quit_now){

1449

959

}

1450

960

written += (size_t)ret;

1451

961

}

1452

ret = fflush(stdout);

1453

if(ret != 0){

1454

int e = errno;

1455

if(debug){

1456

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

1457

strerror(errno));

1458

}

1459

errno = e;

1460

goto mandos_end;

1461

}

1462

962

retval = 0;

1463

963

}

1464

964

}

1467

967

1468

968

mandos_end:

1469

969

{

1470

if(route_added){

1471

if(not delete_local_route(ip, if_index)){

1472

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

1473

" interface %d", ip, if_index);

1474

}

1475

}

1476

970

int e = errno;

1477

971

free(decrypted_buffer);

1478

972

free(buffer);

1479

973

if(tcp_sd >= 0){

1480

ret = close(tcp_sd);

974

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

1481

975

}

1482

976

if(ret == -1){

1483

977

if(e == 0){

1508

1002

AVAHI_GCC_UNUSED AvahiStringList *txt,

1509

1003

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1510

1004

flags,

1511

void *mc){

1005

AVAHI_GCC_UNUSED void* userdata){

1512

1006

if(r == NULL){

1513

1007

return;

1514

1008

}

1517

1011

timed out */

1518

1012

1519

1013

if(quit_now){

1520

avahi_s_service_resolver_free(r);

1521

1014

return;

1522

1015

}

1523

1016

1527

1020

fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "

1528

1021

"'%s' of type '%s' in domain '%s': %s\n", name, type,

1529

1022

domain,

1530

avahi_strerror(avahi_server_errno

1531

(((mandos_context*)mc)->server)));

1023

avahi_strerror(avahi_server_errno(mc.server)));

1532

1024

break;

1533

1025

1534

1026

case AVAHI_RESOLVER_FOUND:

1542

1034

}

1543

1035

int ret = start_mandos_communication(ip, (in_port_t)port,

1544

1036

interface,

1545

avahi_proto_to_af(proto),

1546

mc);

1037

avahi_proto_to_af(proto));

1547

1038

if(ret == 0){

1548

1039

avahi_simple_poll_quit(simple_poll);

1549

1040

} else {

1550

1041

if(not add_server(ip, (in_port_t)port, interface,

1551

avahi_proto_to_af(proto),

1552

&((mandos_context*)mc)->current_server)){

1042

avahi_proto_to_af(proto))){

1553

1043

fprintf_plus(stderr, "Failed to add server \"%s\" to server"

1554

1044

" list\n", name);

1555

1045

}

1568

1058

const char *domain,

1569

1059

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1570

1060

flags,

1571

void *mc){

1061

AVAHI_GCC_UNUSED void* userdata){

1572

1062

if(b == NULL){

1573

1063

return;

1574

1064

}

1585

1075

case AVAHI_BROWSER_FAILURE:

1586

1076

1587

1077

fprintf_plus(stderr, "(Avahi browser) %s\n",

1588

avahi_strerror(avahi_server_errno

1589

(((mandos_context*)mc)->server)));

1078

avahi_strerror(avahi_server_errno(mc.server)));

1590

1079

avahi_simple_poll_quit(simple_poll);

1591

1080

return;

1592

1081

1596

1085

the callback function is called the Avahi server will free the

1597

1086

resolver for us. */

1598

1087

1599

if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,

1600

interface, protocol, name, type,

1601

domain, protocol, 0,

1602

resolve_callback, mc) == NULL)

1088

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1089

name, type, domain, protocol, 0,

1090

resolve_callback, NULL) == NULL)

1603

1091

fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"

1604

1092

" %s\n", name,

1605

avahi_strerror(avahi_server_errno

1606

(((mandos_context*)mc)->server)));

1093

avahi_strerror(avahi_server_errno(mc.server)));

1607

1094

break;

1608

1095

1609

1096

case AVAHI_BROWSER_REMOVE:

1634

1121

errno = old_errno;

1635

1122

}

1636

1123

1637

__attribute__((nonnull, warn_unused_result))

1638

1124

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

1639

1125

int ret;

1640

int old_errno;

1126

error_t ret_errno;

1641

1127

1642

1128

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

1643

1129

if(s < 0){

1644

old_errno = errno;

1130

ret_errno = errno;

1645

1131

perror_plus("socket");

1646

errno = old_errno;

1132

errno = ret_errno;

1647

1133

return false;

1648

1134

}

1649

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

1650

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

1135

strcpy(ifr->ifr_name, ifname);

1651

1136

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1652

1137

if(ret == -1){

1653

1138

if(debug){

1654

old_errno = errno;

1139

ret_errno = errno;

1655

1140

perror_plus("ioctl SIOCGIFFLAGS");

1656

errno = old_errno;

1141

errno = ret_errno;

1657

1142

}

1658

1143

return false;

1659

1144

}

1660

1145

return true;

1661

1146

}

1662

1147

1663

__attribute__((nonnull, warn_unused_result))

1664

1148

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

1665

1149

1666

1150

/* Reject the loopback device */

1708

1192

* corresponds to an acceptable network device.

1709

1193

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

1710

1194

*/

1711

__attribute__((nonnull, warn_unused_result))

1712

1195

int good_interface(const struct dirent *if_entry){

1713

1196

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

1714

1197

return 0;

1732

1215

/*

1733

1216

* This function determines if a network interface is up.

1734

1217

*/

1735

__attribute__((nonnull, warn_unused_result))

1736

1218

bool interface_is_up(const char *interface){

1737

1219

struct ifreq ifr;

1738

1220

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

1749

1231

/*

1750

1232

* This function determines if a network interface is running

1751

1233

*/

1752

__attribute__((nonnull, warn_unused_result))

1753

1234

bool interface_is_running(const char *interface){

1754

1235

struct ifreq ifr;

1755

1236

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

1763

1244

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

1764

1245

}

1765

1246

1766

__attribute__((nonnull, pure, warn_unused_result))

1767

1247

int notdotentries(const struct dirent *direntry){

1768

1248

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

1769

1249

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

1776

1256

}

1777

1257

1778

1258

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

1779

__attribute__((nonnull, warn_unused_result))

1780

1259

int runnable_hook(const struct dirent *direntry){

1781

1260

int ret;

1782

1261

size_t sret;

1790

1269

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

1791

1270

"abcdefghijklmnopqrstuvwxyz"

1792

1271

"0123456789"

1793

"_.-");

1272

"_-");

1794

1273

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

1795

1274

/* Contains non-allowed characters */

1796

1275

if(debug){

1800

1279

return 0;

1801

1280

}

1802

1281

1803

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

1282

char *fullname = NULL;

1283

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

1284

if(ret < 0){

1285

perror_plus("asprintf");

1286

return 0;

1287

}

1288

1289

ret = stat(fullname, &st);

1804

1290

if(ret == -1){

1805

1291

if(debug){

1806

1292

perror_plus("Could not stat hook");

1830

1316

return 1;

1831

1317

}

1832

1318

1833

__attribute__((nonnull, warn_unused_result))

1834

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1835

mandos_context *mc){

1319

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1836

1320

int ret;

1837

1321

struct timespec now;

1838

1322

struct timespec waited_time;

1839

1323

intmax_t block_time;

1840

1324

1841

1325

while(true){

1842

if(mc->current_server == NULL){

1843

if(debug){

1326

if(mc.current_server == NULL){

1327

if (debug){

1844

1328

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

1845

1329

" No timeout!\n");

1846

1330

}

1847

1331

ret = avahi_simple_poll_iterate(s, -1);

1848

1332

} else {

1849

if(debug){

1333

if (debug){

1850

1334

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

1851

1335

" it, or wait\n");

1852

1336

}

1859

1343

/* Calculating in ms how long time between now and server

1860

1344

who we visted longest time ago. Now - last seen. */

1861

1345

waited_time.tv_sec = (now.tv_sec

1862

- mc->current_server->last_seen.tv_sec);

1346

- mc.current_server->last_seen.tv_sec);

1863

1347

waited_time.tv_nsec = (now.tv_nsec

1864

- mc->current_server->last_seen.tv_nsec);

1348

- mc.current_server->last_seen.tv_nsec);

1865

1349

/* total time is 10s/10,000ms.

1866

1350

Converting to s from ms by dividing by 1,000,

1867

1351

and ns to ms by dividing by 1,000,000. */

1869

1353

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

1870

1354

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

1871

1355

1872

if(debug){

1356

if (debug){

1873

1357

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

1874

1358

block_time);

1875

1359

}

1876

1360

1877

1361

if(block_time <= 0){

1878

ret = start_mandos_communication(mc->current_server->ip,

1879

mc->current_server->port,

1880

mc->current_server->if_index,

1881

mc->current_server->af, mc);

1362

ret = start_mandos_communication(mc.current_server->ip,

1363

mc.current_server->port,

1364

mc.current_server->if_index,

1365

mc.current_server->af);

1882

1366

if(ret == 0){

1883

avahi_simple_poll_quit(s);

1367

avahi_simple_poll_quit(simple_poll);

1884

1368

return 0;

1885

1369

}

1886

1370

ret = clock_gettime(CLOCK_MONOTONIC,

1887

&mc->current_server->last_seen);

1371

&mc.current_server->last_seen);

1888

1372

if(ret == -1){

1889

1373

perror_plus("clock_gettime");

1890

1374

return -1;

1891

1375

}

1892

mc->current_server = mc->current_server->next;

1376

mc.current_server = mc.current_server->next;

1893

1377

block_time = 0; /* Call avahi to find new Mandos

1894

1378

servers, but don't block */

1895

1379

}

1897

1381

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

1898

1382

}

1899

1383

if(ret != 0){

1900

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

1384

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

1901

1385

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

1902

1386

}

1903

1387

}

1904

1388

}

1905

1389

}

1906

1390

1907

__attribute__((nonnull))

1908

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

1391

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

1392

error_t raise_privileges(void){

1393

error_t old_errno = errno;

1394

error_t ret_errno = 0;

1395

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

1396

ret_errno = errno;

1397

perror_plus("seteuid");

1398

}

1399

errno = old_errno;

1400

return ret_errno;

1401

}

1402

1403

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

1404

error_t raise_privileges_permanently(void){

1405

error_t old_errno = errno;

1406

error_t ret_errno = raise_privileges();

1407

if(ret_errno != 0){

1408

errno = old_errno;

1409

return ret_errno;

1410

}

1411

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

1412

ret_errno = errno;

1413

perror_plus("seteuid");

1414

}

1415

errno = old_errno;

1416

return ret_errno;

1417

}

1418

1419

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

1420

error_t lower_privileges(void){

1421

error_t old_errno = errno;

1422

error_t ret_errno = 0;

1423

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

1424

ret_errno = errno;

1425

perror_plus("seteuid");

1426

}

1427

errno = old_errno;

1428

return ret_errno;

1429

}

1430

1431

/* Lower privileges permanently */

1432

error_t lower_privileges_permanently(void){

1433

error_t old_errno = errno;

1434

error_t ret_errno = 0;

1435

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

1436

ret_errno = errno;

1437

perror_plus("setuid");

1438

}

1439

errno = old_errno;

1440

return ret_errno;

1441

}

1442

1443

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

1909

1444

const float delay){

1910

struct dirent **direntries = NULL;

1911

if(hookdir_fd == -1){

1912

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1913

| O_CLOEXEC);

1914

if(hookdir_fd == -1){

1915

if(errno == ENOENT){

1916

if(debug){

1917

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

1918

" found\n", hookdir);

1919

}

1920

} else {

1921

perror_plus("open");

1922

}

1923

return;

1924

}

1925

}

1926

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

1927

runnable_hook, alphasort);

1445

struct dirent **direntries;

1446

struct dirent *direntry;

1447

int ret;

1448

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

1449

alphasort);

1928

1450

if(numhooks == -1){

1929

perror_plus("scandir");

1930

return;

1931

}

1932

struct dirent *direntry;

1933

int ret;

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1939

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

1940

direntry = direntries[i];

1941

if(debug){

1942

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

1943

direntry->d_name);

1451

if(errno == ENOENT){

1452

if(debug){

1453

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

1454

" found\n", hookdir);

1455

}

1456

} else {

1457

perror_plus("scandir");

1944

1458

}

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

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

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

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

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

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

1990

if(ret == -1){

1459

} else {

1460

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

1461

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

1462

direntry = direntries[i];

1463

char *fullname = NULL;

1464

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

1465

if(ret < 0){

1991

1466

perror_plus("asprintf");

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1467

continue;

1468

}

1469

if(debug){

1470

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

1471

direntry->d_name);

1472

}

1473

pid_t hook_pid = fork();

1474

if(hook_pid == 0){

1475

/* Child */

1476

/* Raise privileges */

1477

raise_privileges_permanently();

1478

/* Set group */

1479

errno = 0;

1480

ret = setgid(0);

1481

if(ret == -1){

1482

perror_plus("setgid");

1483

}

1484

/* Reset supplementary groups */

1485

errno = 0;

1486

ret = setgroups(0, NULL);

1487

if(ret == -1){

1488

perror_plus("setgroups");

1489

}

1490

dup2(devnull, STDIN_FILENO);

1491

close(devnull);

1492

dup2(STDERR_FILENO, STDOUT_FILENO);

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

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

1509

if(ret == -1){

1510

perror_plus("setenv");

1511

_exit(EX_OSERR);

1512

}

1513

char *delaystring;

1514

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

1515

if(ret == -1){

1516

perror_plus("asprintf");

1517

_exit(EX_OSERR);

1518

}

1519

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

1520

if(ret == -1){

1521

free(delaystring);

1522

perror_plus("setenv");

1523

_exit(EX_OSERR);

1524

}

1996

1525

free(delaystring);

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

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

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

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

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

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

2054

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

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

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

2061

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

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

1526

if(connect_to != NULL){

1527

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

1528

if(ret == -1){

1529

perror_plus("setenv");

1530

_exit(EX_OSERR);

1531

}

1532

}

1533

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

1534

perror_plus("execl");

1535

_exit(EXIT_FAILURE);

1536

}

2065

1537

} else {

2066

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

2067

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

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

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

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

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

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

1538

int status;

1539

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

1540

perror_plus("waitpid");

1541

free(fullname);

1542

continue;

1543

}

1544

if(WIFEXITED(status)){

1545

if(WEXITSTATUS(status) != 0){

1546

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

1547

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

1548

WEXITSTATUS(status));

1549

free(fullname);

1550

continue;

1551

}

1552

} else if(WIFSIGNALED(status)){

1553

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

1554

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

1555

WTERMSIG(status));

1556

free(fullname);

1557

continue;

1558

} else {

1559

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

1560

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

1561

free(fullname);

1562

continue;

1563

}

1564

}

1565

free(fullname);

1566

if(debug){

1567

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

1568

direntry->d_name);

1569

}

1570

}

1571

close(devnull);

1572

}

1573

return true;

2085

1574

}

2086

1575

2087

__attribute__((nonnull, warn_unused_result))

2088

int bring_up_interface(const char *const interface,

2089

const float delay){

2090

int old_errno = errno;

2091

int ret;

1576

error_t bring_up_interface(const char *const interface,

1577

const float delay){

1578

int sd = -1;

1579

error_t old_errno = errno;

1580

error_t ret_errno = 0;

1581

int ret, ret_setflags;

2092

1582

struct ifreq network;

2093

1583

unsigned int if_index = if_nametoindex(interface);

2094

1584

if(if_index == 0){

2103

1593

}

2104

1594

2105

1595

if(not interface_is_up(interface)){

2106

int ret_errno = 0;

2107

int ioctl_errno = 0;

2108

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

1596

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

2109

1597

ret_errno = errno;

2110

1598

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

2111

1599

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

2112

errno = old_errno;

2113

1600

return ret_errno;

2114

1601

}

2115

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

1602

network.ifr_flags |= IFF_UP;

2116

1603

2117

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

2118

if(sd == -1){

1604

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1605

if(sd < 0){

2119

1606

ret_errno = errno;

2120

1607

perror_plus("socket");

2121

1608

errno = old_errno;

2122

1609

return ret_errno;

2123

1610

}

2124

1611

2125

1612

if(quit_now){

2126

ret = close(sd);

2127

if(ret == -1){

2128

perror_plus("close");

2129

}

1613

close(sd);

2130

1614

errno = old_errno;

2131

1615

return EINTR;

2132

1616

}

2136

1620

interface);

2137

1621

}

2138

1622

2139

/* Raise privileges */

2140

ret_errno = raise_privileges();

2141

if(ret_errno != 0){

2142

errno = ret_errno;

2143

perror_plus("Failed to raise privileges");

2144

}

1623

/* Raise priviliges */

1624

raise_privileges();

2145

1625

2146

1626

#ifdef __linux__

2147

int ret_linux;

2148

bool restore_loglevel = false;

2149

if(ret_errno == 0){

2150

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2151

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

2152

ret_linux = klogctl(8, NULL, 5);

2153

if(ret_linux == -1){

2154

perror_plus("klogctl");

2155

} else {

2156

restore_loglevel = true;

2157

}

1627

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1628

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

1629

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

1630

bool restore_loglevel = true;

1631

if(ret_linux == -1){

1632

restore_loglevel = false;

1633

perror_plus("klogctl");

2158

1634

}

2159

1635

#endif /* __linux__ */

2160

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

2161

ioctl_errno = errno;

1636

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

1637

ret_errno = errno;

2162

1638

#ifdef __linux__

2163

1639

if(restore_loglevel){

2164

1640

ret_linux = klogctl(7, NULL, 0);

2168

1644

}

2169

1645

#endif /* __linux__ */

2170

1646

2171

/* If raise_privileges() succeeded above */

2172

if(ret_errno == 0){

2173

/* Lower privileges */

2174

ret_errno = lower_privileges();

2175

if(ret_errno != 0){

2176

errno = ret_errno;

2177

perror_plus("Failed to lower privileges");

2178

}

2179

}

1647

/* Lower privileges */

1648

lower_privileges();

2180

1649

2181

1650

/* Close the socket */

2182

ret = close(sd);

1651

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

2183

1652

if(ret == -1){

2184

1653

perror_plus("close");

2185

1654

}

2186

1655

2187

1656

if(ret_setflags == -1){

2188

errno = ioctl_errno;

1657

errno = ret_errno;

2189

1658

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2190

1659

errno = old_errno;

2191

return ioctl_errno;

1660

return ret_errno;

2192

1661

}

2193

1662

} else if(debug){

2194

1663

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

2197

1666

2198

1667

/* Sleep checking until interface is running.

2199

1668

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

2200

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

1669

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

2201

1670

if(interface_is_running(interface)){

2202

1671

break;

2203

1672

}

2212

1681

return 0;

2213

1682

}

2214

1683

2215

__attribute__((nonnull, warn_unused_result))

2216

int take_down_interface(const char *const interface){

2217

int old_errno = errno;

1684

error_t take_down_interface(const char *const interface){

1685

int sd = -1;

1686

error_t old_errno = errno;

1687

error_t ret_errno = 0;

1688

int ret, ret_setflags;

2218

1689

struct ifreq network;

2219

1690

unsigned int if_index = if_nametoindex(interface);

2220

1691

if(if_index == 0){

2223

1694

return ENXIO;

2224

1695

}

2225

1696

if(interface_is_up(interface)){

2226

int ret_errno = 0;

2227

int ioctl_errno = 0;

2228

1697

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

2229

1698

ret_errno = errno;

2230

1699

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

2231

1700

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

2232

errno = old_errno;

2233

1701

return ret_errno;

2234

1702

}

2235

1703

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

2236

1704

2237

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

2238

if(sd == -1){

1705

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1706

if(sd < 0){

2239

1707

ret_errno = errno;

2240

1708

perror_plus("socket");

2241

1709

errno = old_errno;

2247

1715

interface);

2248

1716

}

2249

1717

2250

/* Raise privileges */

2251

ret_errno = raise_privileges();

2252

if(ret_errno != 0){

2253

errno = ret_errno;

2254

perror_plus("Failed to raise privileges");

2255

}

2256

2257

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

2258

ioctl_errno = errno;

2259

2260

/* If raise_privileges() succeeded above */

2261

if(ret_errno == 0){

2262

/* Lower privileges */

2263

ret_errno = lower_privileges();

2264

if(ret_errno != 0){

2265

errno = ret_errno;

2266

perror_plus("Failed to lower privileges");

2267

}

2268

}

1718

/* Raise priviliges */

1719

raise_privileges();

1720

1721

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

1722

ret_errno = errno;

1723

1724

/* Lower privileges */

1725

lower_privileges();

2269

1726

2270

1727

/* Close the socket */

2271

int ret = close(sd);

1728

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

2272

1729

if(ret == -1){

2273

1730

perror_plus("close");

2274

1731

}

2275

1732

2276

1733

if(ret_setflags == -1){

2277

errno = ioctl_errno;

1734

errno = ret_errno;

2278

1735

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2279

1736

errno = old_errno;

2280

return ioctl_errno;

1737

return ret_errno;

2281

1738

}

2282

1739

} else if(debug){

2283

1740

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

2289

1746

}

2290

1747

2291

1748

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

2292

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

2293

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

2294

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

2295

.current_server = NULL, .interfaces = NULL,

2296

.interfaces_size = 0 };

2297

1749

AvahiSServiceBrowser *sb = NULL;

2298

1750

error_t ret_errno;

2299

1751

int ret;

2300

1752

intmax_t tmpmax;

2301

1753

char *tmp;

2302

1754

int exitcode = EXIT_SUCCESS;

1755

char *interfaces = NULL;

1756

size_t interfaces_size = 0;

2303

1757

char *interfaces_to_take_down = NULL;

2304

1758

size_t interfaces_to_take_down_size = 0;

2305

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

2306

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

2307

char *tempdir = NULL;

1759

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

1760

bool tempdir_created = false;

2308

1761

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2309

1762

const char *seckey = PATHDIR "/" SECKEY;

2310

1763

const char *pubkey = PATHDIR "/" PUBKEY;

2311

const char *dh_params_file = NULL;

2312

1764

char *interfaces_hooks = NULL;

1765

size_t interfaces_hooks_size = 0;

2313

1766

2314

1767

bool gnutls_initialized = false;

2315

1768

bool gpgme_initialized = false;

2367

1820

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

2368

1821

" Diffie-Hellman key exchange",

2369

1822

.group = 2 },

2370

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

2371

.arg = "FILE",

2372

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

2373

" for the Diffie-Hellman key exchange",

2374

.group = 2 },

2375

1823

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

2376

1824

.arg = "STRING",

2377

1825

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

2411

1859

connect_to = arg;

2412

1860

break;

2413

1861

case 'i': /* --interface */

2414

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

2415

arg, (int)',');

1862

ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,

1863

(int)',');

2416

1864

if(ret_errno != 0){

2417

1865

argp_error(state, "%s", strerror(ret_errno));

2418

1866

}

2432

1880

}

2433

1881

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

2434

1882

break;

2435

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

2436

dh_params_file = arg;

2437

break;

2438

1883

case 130: /* --priority */

2439

1884

mc.priority = arg;

2440

1885

break;

2480

1925

.args_doc = "",

2481

1926

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

2482

1927

" passwords from a Mandos server" };

2483

ret_errno = argp_parse(&argp, argc, argv,

2484

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2485

switch(ret_errno){

1928

ret = argp_parse(&argp, argc, argv,

1929

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1930

switch(ret){

2486

1931

case 0:

2487

1932

break;

2488

1933

case ENOMEM:

2489

1934

default:

2490

errno = ret_errno;

1935

errno = ret;

2491

1936

perror_plus("argp_parse");

2492

1937

exitcode = EX_OSERR;

2493

1938

goto end;

2496

1941

goto end;

2497

1942

}

2498

1943

}

2499

1944

2500

1945

{

2501

1946

/* Work around Debian bug #633582:

2502

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

1947

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

2503

1948

2504

/* Re-raise privileges */

2505

ret = raise_privileges();

2506

if(ret != 0){

2507

errno = ret;

2508

perror_plus("Failed to raise privileges");

2509

} else {

1949

/* Re-raise priviliges */

1950

if(raise_privileges() == 0){

2510

1951

struct stat st;

2511

1952

2512

1953

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

2526

1967

}

2527

1968

}

2528

1969

}

2529

close(seckey_fd);

1970

TEMP_FAILURE_RETRY(close(seckey_fd));

2530

1971

}

2531

1972

}

2532

1973

2533

1974

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

2534

1975

int pubkey_fd = open(pubkey, O_RDONLY);

2535

1976

if(pubkey_fd == -1){

2547

1988

}

2548

1989

}

2549

1990

}

2550

close(pubkey_fd);

2551

}

2552

}

2553

2554

if(dh_params_file != NULL

2555

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

2556

int dhparams_fd = open(dh_params_file, O_RDONLY);

2557

if(dhparams_fd == -1){

2558

perror_plus("open");

2559

} else {

2560

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

2561

if(ret == -1){

2562

perror_plus("fstat");

2563

} else {

2564

if(S_ISREG(st.st_mode)

2565

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

2566

ret = fchown(dhparams_fd, uid, gid);

2567

if(ret == -1){

2568

perror_plus("fchown");

2569

}

2570

}

2571

}

2572

close(dhparams_fd);

2573

}

2574

}

2575

1991

TEMP_FAILURE_RETRY(close(pubkey_fd));

1992

}

1993

}

1994

2576

1995

/* Lower privileges */

2577

ret = lower_privileges();

2578

if(ret != 0){

2579

errno = ret;

2580

perror_plus("Failed to lower privileges");

1996

errno = 0;

1997

ret = seteuid(uid);

1998

if(ret == -1){

1999

perror_plus("seteuid");

2581

2000

}

2582

2001

}

2583

2002

}

2584

2003

2585

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

2004

/* Remove empty interface names */

2586

2005

{

2587

2006

char *interface = NULL;

2588

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

2007

while((interface = argz_next(interfaces, interfaces_size,

2589

2008

interface))){

2590

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

2591

and if_nametoindex(interface) == 0){

2592

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

2009

if(if_nametoindex(interface) == 0){

2010

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

2593

2011

fprintf_plus(stderr, "Not using nonexisting interface"

2594

2012

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

2595

2013

}

2596

argz_delete(&mc.interfaces, &mc.interfaces_size, interface);

2014

argz_delete(&interfaces, &interfaces_size, interface);

2597

2015

interface = NULL;

2598

2016

}

2599

2017

}

2601

2019

2602

2020

/* Run network hooks */

2603

2021

{

2604

if(mc.interfaces != NULL){

2605

interfaces_hooks = malloc(mc.interfaces_size);

2022

2023

if(interfaces != NULL){

2024

interfaces_hooks = malloc(interfaces_size);

2606

2025

if(interfaces_hooks == NULL){

2607

2026

perror_plus("malloc");

2608

2027

goto end;

2609

2028

}

2610

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

2611

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

2612

}

2613

run_network_hooks("start", interfaces_hooks != NULL ?

2614

interfaces_hooks : "", delay);

2029

memcpy(interfaces_hooks, interfaces, interfaces_size);

2030

interfaces_hooks_size = interfaces_size;

2031

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2032

(int)',');

2033

}

2034

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

2035

interfaces_hooks : "", delay)){

2036

goto end;

2037

}

2615

2038

}

2616

2039

2617

2040

if(not debug){

2694

2117

}

2695

2118

2696

2119

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

2697

if(mc.interfaces == NULL){

2698

struct dirent **direntries = NULL;

2120

if(interfaces == NULL){

2121

struct dirent **direntries;

2699

2122

/* Look for any good interfaces */

2700

2123

ret = scandir(sys_class_net, &direntries, good_interface,

2701

2124

alphasort);

2702

2125

if(ret >= 1){

2703

2126

/* Add all found interfaces to interfaces list */

2704

2127

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

2705

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

2128

ret_errno = argz_add(&interfaces, &interfaces_size,

2706

2129

direntries[i]->d_name);

2707

2130

if(ret_errno != 0){

2708

errno = ret_errno;

2709

2131

perror_plus("argz_add");

2710

free(direntries[i]);

2711

2132

continue;

2712

2133

}

2713

2134

if(debug){

2714

2135

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

2715

2136

direntries[i]->d_name);

2716

2137

}

2717

free(direntries[i]);

2718

2138

}

2719

2139

free(direntries);

2720

2140

} else {

2721

if(ret == 0){

2722

free(direntries);

2723

}

2141

free(direntries);

2724

2142

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

2725

2143

exitcode = EXIT_FAILURE;

2726

2144

goto end;

2727

2145

}

2728

2146

}

2729

2147

2730

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

2731

{

2148

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

2149

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

2150

if(debug){

2151

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2152

interfaces);

2153

}

2154

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2155

}

2156

2157

/* Bring up interfaces which are down */

2158

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

2159

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

2732

2160

char *interface = NULL;

2733

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

2161

while((interface = argz_next(interfaces, interfaces_size,

2734

2162

interface))){

2735

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

2736

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

2737

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

2738

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

2739

interface);

2740

interface = NULL;

2741

while((interface = argz_next(mc.interfaces,

2742

mc.interfaces_size, interface))){

2743

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

2744

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

2745

interface);

2746

interface = NULL;

2747

}

2748

}

2749

break;

2750

}

2751

2163

bool interface_was_up = interface_is_up(interface);

2752

errno = bring_up_interface(interface, delay);

2164

ret = bring_up_interface(interface, delay);

2753

2165

if(not interface_was_up){

2754

if(errno != 0){

2755

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

2756

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

2166

if(ret != 0){

2167

errno = ret;

2168

perror_plus("Failed to bring up interface");

2757

2169

} else {

2758

errno = argz_add(&interfaces_to_take_down,

2759

&interfaces_to_take_down_size,

2760

interface);

2761

if(errno != 0){

2762

perror_plus("argz_add");

2763

}

2170

ret_errno = argz_add(&interfaces_to_take_down,

2171

&interfaces_to_take_down_size,

2172

interface);

2764

2173

}

2765

2174

}

2766

2175

}

2176

free(interfaces);

2177

interfaces = NULL;

2178

interfaces_size = 0;

2767

2179

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

2768

2180

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

2769

2181

}

2770

2182

}

2771

2183

2772

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

2773

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

2774

if(debug){

2775

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2776

mc.interfaces);

2777

}

2778

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

2779

}

2780

2781

2184

if(quit_now){

2782

2185

goto end;

2783

2186

}

2784

2187

2785

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

2188

ret = init_gnutls_global(pubkey, seckey);

2786

2189

if(ret == -1){

2787

2190

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

2788

2191

exitcode = EX_UNAVAILABLE;

2795

2198

goto end;

2796

2199

}

2797

2200

2798

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

2799

tempdir = mkdtemp(run_tempdir);

2800

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

2801

if(debug){

2802

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

2803

run_tempdir, old_tempdir);

2804

}

2805

tempdir = mkdtemp(old_tempdir);

2806

}

2807

if(tempdir == NULL){

2201

if(mkdtemp(tempdir) == NULL){

2808

2202

perror_plus("mkdtemp");

2809

2203

goto end;

2810

2204

}

2205

tempdir_created = true;

2811

2206

2812

2207

if(quit_now){

2813

2208

goto end;

2814

2209

}

2815

2210

2816

if(not init_gpgme(pubkey, seckey, tempdir, &mc)){

2211

if(not init_gpgme(pubkey, seckey, tempdir)){

2817

2212

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

2818

2213

exitcode = EX_UNAVAILABLE;

2819

2214

goto end;

2849

2244

exitcode = EX_USAGE;

2850

2245

goto end;

2851

2246

}

2852

2247

2853

2248

if(quit_now){

2854

2249

goto end;

2855

2250

}

2876

2271

}

2877

2272

2878

2273

while(not quit_now){

2879

ret = start_mandos_communication(address, port, if_index, af,

2880

&mc);

2274

ret = start_mandos_communication(address, port, if_index, af);

2881

2275

if(quit_now or ret == 0){

2882

2276

break;

2883

2277

}

2885

2279

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

2886

2280

(int)retry_interval);

2887

2281

}

2888

sleep((unsigned int)retry_interval);

2282

sleep((int)retry_interval);

2889

2283

}

2890

2284

2891

if(not quit_now){

2285

if (not quit_now){

2892

2286

exitcode = EXIT_SUCCESS;

2893

2287

}

2894

2288

2910

2304

2911

2305

/* Allocate a new server */

2912

2306

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2913

&config, NULL, NULL, &ret);

2307

&config, NULL, NULL, &ret_errno);

2914

2308

2915

2309

/* Free the Avahi configuration data */

2916

2310

avahi_server_config_free(&config);

2919

2313

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

2920

2314

if(mc.server == NULL){

2921

2315

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

2922

avahi_strerror(ret));

2316

avahi_strerror(ret_errno));

2923

2317

exitcode = EX_UNAVAILABLE;

2924

2318

goto end;

2925

2319

}

2931

2325

/* Create the Avahi service browser */

2932

2326

sb = avahi_s_service_browser_new(mc.server, if_index,

2933

2327

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2934

NULL, 0, browse_callback,

2935

(void *)&mc);

2328

NULL, 0, browse_callback, NULL);

2936

2329

if(sb == NULL){

2937

2330

fprintf_plus(stderr, "Failed to create service browser: %s\n",

2938

2331

avahi_strerror(avahi_server_errno(mc.server)));

2949

2342

if(debug){

2950

2343

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

2951

2344

}

2952

2345

2953

2346

ret = avahi_loop_with_timeout(simple_poll,

2954

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

2347

(int)(retry_interval * 1000));

2955

2348

if(debug){

2956

2349

fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",

2957

2350

(ret == 0) ? "successfully" : "with error");

2960

2353

end:

2961

2354

2962

2355

if(debug){

2963

if(signal_received){

2964

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

2965

argv[0], signal_received,

2966

strsignal(signal_received));

2967

} else {

2968

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

2969

}

2356

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

2970

2357

}

2971

2358

2972

2359

/* Cleanup things */

2973

free(mc.interfaces);

2974

2975

2360

if(sb != NULL)

2976

2361

avahi_s_service_browser_free(sb);

2977

2362

2983

2368

2984

2369

if(gnutls_initialized){

2985

2370

gnutls_certificate_free_credentials(mc.cred);

2371

gnutls_global_deinit();

2986

2372

gnutls_dh_params_deinit(mc.dh_params);

2987

2373

}

2988

2374

2996

2382

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

2997

2383

while(mc.current_server != NULL){

2998

2384

server *next = mc.current_server->next;

2999

#ifdef __GNUC__

3000

#pragma GCC diagnostic push

3001

#pragma GCC diagnostic ignored "-Wcast-qual"

3002

#endif

3003

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

3004

#ifdef __GNUC__

3005

#pragma GCC diagnostic pop

3006

#endif

3007

2385

free(mc.current_server);

3008

2386

mc.current_server = next;

3009

2387

}

3010

2388

}

3011

2389

3012

/* Re-raise privileges */

2390

/* Re-raise priviliges */

3013

2391

{

3014

ret = raise_privileges();

3015

if(ret != 0){

3016

errno = ret;

3017

perror_plus("Failed to raise privileges");

3018

} else {

3019

3020

/* Run network hooks */

3021

run_network_hooks("stop", interfaces_hooks != NULL ?

3022

interfaces_hooks : "", delay);

3023

3024

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

3025

{

3026

char *interface = NULL;

3027

while((interface = argz_next(interfaces_to_take_down,

3028

interfaces_to_take_down_size,

3029

interface))){

3030

ret = take_down_interface(interface);

3031

if(ret != 0){

3032

errno = ret;

3033

perror_plus("Failed to take down interface");

3034

}

3035

}

3036

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

3037

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

3038

" down\n");

3039

}

3040

}

3041

}

3042

3043

ret = lower_privileges_permanently();

3044

if(ret != 0){

3045

errno = ret;

3046

perror_plus("Failed to lower privileges permanently");

3047

}

2392

raise_privileges();

2393

2394

/* Run network hooks */

2395

run_network_hooks("stop", interfaces_hooks != NULL ?

2396

interfaces_hooks : "", delay);

2397

2398

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

2399

{

2400

char *interface = NULL;

2401

while((interface=argz_next(interfaces_to_take_down,

2402

interfaces_to_take_down_size,

2403

interface))){

2404

ret_errno = take_down_interface(interface);

2405

if(ret_errno != 0){

2406

errno = ret_errno;

2407

perror_plus("Failed to take down interface");

2408

}

2409

}

2410

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

2411

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

2412

" down\n");

2413

}

2414

}

2415

2416

lower_privileges_permanently();

3048

2417

}

3049

2418

3050

2419

free(interfaces_to_take_down);

3051

2420

free(interfaces_hooks);

3052

2421

3053

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

3054

uintmax_t level){

2422

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

2423

if(tempdir_created){

3055

2424

struct dirent **direntries = NULL;

3056

int dret;

3057

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

3058

O_RDONLY

3059

| O_NOFOLLOW

3060

| O_DIRECTORY

3061

| O_PATH));

3062

if(dir_fd == -1){

3063

perror_plus("open");

3064

}

3065

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

3066

notdotentries, alphasort);

3067

if(numentries >= 0){

2425

struct dirent *direntry = NULL;

2426

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

2427

alphasort);

2428

if (numentries > 0){

3068

2429

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

3069

if(debug){

3070

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

3071

dirname, direntries[i]->d_name);

3072

}

3073

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

3074

if(dret == -1){

3075

if(errno == EISDIR){

3076

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

3077

AT_REMOVEDIR);

3078

}

3079

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

3080

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

3081

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

3082

/* Recurse only in this special case */

3083

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

3084

dret = 0;

3085

}

3086

if(dret == -1){

3087

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

3088

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

3089

}

3090

}

3091

free(direntries[i]);

3092

}

3093

3094

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

3095

free(direntries);

3096

if(numentries == -1){

3097

perror_plus("scandirat");

3098

}

3099

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3100

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

3101

perror_plus("rmdir");

3102

}

3103

} else {

3104

perror_plus("scandirat");

3105

}

3106

close(dir_fd);

3107

}

3108

3109

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

3110

if(tempdir != NULL){

3111

clean_dir_at(-1, tempdir, 0);

2430

direntry = direntries[i];

2431

char *fullname = NULL;

2432

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

2433

direntry->d_name);

2434

if(ret < 0){

2435

perror_plus("asprintf");

2436

continue;

2437

}

2438

ret = remove(fullname);

2439

if(ret == -1){

2440

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

2441

strerror(errno));

2442

}

2443

free(fullname);

2444

}

2445

}

2446

2447

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

2448

free(direntries);

2449

if (numentries == -1){

2450

perror_plus("scandir");

2451

}

2452

ret = rmdir(tempdir);

2453

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

2454

perror_plus("rmdir");

2455

}

3112

2456

}

3113

2457

3114

2458

if(quit_now){