/mandos/release : revision 237.7.152

9

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

10

*

11

* Everything else is

12

13

14

*

15

* This file is part of Mandos.

16

*

17

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

18

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

19

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

20

* (at your option) any later version.

21

*

22

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

12

13

14

*

15

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

16

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

17

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

18

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

19

*

20

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

23

21

* WITHOUT ANY WARRANTY; without even the implied warranty of

24

22

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

25

23

* General Public License for more details.

26

24

*

27

25

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

28

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

26

* along with this program. If not, see

27

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

29

28

*

30

29

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

31

30

*/

33

32

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

34

33

#ifndef _LARGEFILE_SOURCE

35

34

#define _LARGEFILE_SOURCE

36

#endif /* not _LARGEFILE_SOURCE */

35

#endif

37

36

#ifndef _FILE_OFFSET_BITS

38

37

#define _FILE_OFFSET_BITS 64

39

#endif /* not _FILE_OFFSET_BITS */

38

#endif

40

39

41

40

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

42

41

43

42

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

44

stdout, ferror() */

43

stdout, ferror(), remove() */

45

44

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

46

45

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

47

46

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

48

47

strtof(), abort() */

49

48

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

50

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

51

asprintf(), strncpy(), strsignal()

52

*/

49

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

50

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

53

51

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

54

52

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

55

53

sockaddr_in6, PF_INET6,

57

55

opendir(), DIR */

58

56

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

59

57

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

60

inet_pton(), connect(),

61

getnameinfo() */

62

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

58

inet_pton(), connect() */

59

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

63

60

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

64

61

*/

65

62

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

66

63

strtoimax() */

67

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

68

EAI_SYSTEM, ENETUNREACH,

69

EHOSTUNREACH, ECONNREFUSED, EPROTO,

70

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

71

ENOTEMPTY,

64

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

72

65

program_invocation_short_name */

73

66

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

74

67

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

79

72

*/

80

73

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

81

74

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

82

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

83

unlinkat() */

84

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

75

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

76

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

85

77

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

86

78

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

87

79

argp_state, struct argp,

99

91

argz_delete(), argz_append(),

100

92

argz_stringify(), argz_add(),

101

93

argz_count() */

102

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

103

EAI_SYSTEM, gai_strerror() */

104

94

105

95

#ifdef __linux__

106

96

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

123

113

gnutls_*

124

114

init_gnutls_session(),

125

115

GNUTLS_* */

126

#if GNUTLS_VERSION_NUMBER < 0x030600

127

116

#include <gnutls/openpgp.h>

128

117

/* gnutls_certificate_set_openpgp_key_file(),

129

118

GNUTLS_OPENPGP_FMT_BASE64 */

130

#elif GNUTLS_VERSION_NUMBER >= 0x030606

131

#include <gnutls/x509.h> /* gnutls_pkcs_encrypt_flags_t,

132

GNUTLS_PKCS_PLAIN,

133

GNUTLS_PKCS_NULL_PASSWORD */

134

#endif

135

119

136

120

/* GPGME */

137

121

#include <gpgme.h> /* All GPGME types, constants and

145

129

#define PATHDIR "/conf/conf.d/mandos"

146

130

#define SECKEY "seckey.txt"

147

131

#define PUBKEY "pubkey.txt"

148

#define TLS_PRIVKEY "tls-privkey.pem"

149

#define TLS_PUBKEY "tls-pubkey.pem"

150

132

#define HOOKDIR "/lib/mandos/network-hooks.d"

151

133

152

134

bool debug = false;

156

138

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

157

139

char *connect_to = NULL;

158

140

const char *hookdir = HOOKDIR;

159

int hookdir_fd = -1;

160

141

uid_t uid = 65534;

161

142

gid_t gid = 65534;

162

143

199

180

perror(print_text);

200

181

}

201

182

202

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

183

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

203

184

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

204

185

va_list ap;

205

186

va_start (ap, format);

206

187

207

188

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

208

189

program_invocation_short_name));

209

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

190

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

210

191

}

211

192

212

193

/*

214

195

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

215

196

* "buffer_length" is how much is already used.

216

197

*/

217

__attribute__((nonnull, warn_unused_result))

218

198

size_t incbuffer(char **buffer, size_t buffer_length,

219

199

size_t buffer_capacity){

220

200

if(buffer_length + BUFFER_SIZE > buffer_capacity){

221

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

222

if(new_buf == NULL){

223

int old_errno = errno;

224

free(*buffer);

225

errno = old_errno;

226

*buffer = NULL;

201

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

202

if(buffer == NULL){

227

203

return 0;

228

204

}

229

*buffer = new_buf;

230

205

buffer_capacity += BUFFER_SIZE;

231

206

}

232

207

return buffer_capacity;

233

208

}

234

209

235

210

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

236

__attribute__((nonnull, warn_unused_result))

237

211

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

238

212

int af, server **current_server){

239

213

int ret;

248

222

.af = af };

249

223

if(new_server->ip == NULL){

250

224

perror_plus("strdup");

251

free(new_server);

252

return false;

253

}

254

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

255

if(ret == -1){

256

perror_plus("clock_gettime");

257

#ifdef __GNUC__

258

#pragma GCC diagnostic push

259

#pragma GCC diagnostic ignored "-Wcast-qual"

260

#endif

261

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

262

#ifdef __GNUC__

263

#pragma GCC diagnostic pop

264

#endif

265

free(new_server);

266

225

return false;

267

226

}

268

227

/* Special case of first server */

270

229

new_server->next = new_server;

271

230

new_server->prev = new_server;

272

231

*current_server = new_server;

232

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

273

233

} else {

274

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

275

234

new_server->next = *current_server;

276

235

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

277

236

new_server->prev->next = new_server;

278

237

(*current_server)->prev = new_server;

279

238

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

280

244

return true;

281

245

}

282

246

283

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

284

__attribute__((warn_unused_result))

285

int raise_privileges(void){

286

int old_errno = errno;

287

int ret = 0;

288

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

289

ret = errno;

290

}

291

errno = old_errno;

292

return ret;

293

}

294

295

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

296

__attribute__((warn_unused_result))

297

int raise_privileges_permanently(void){

298

int old_errno = errno;

299

int ret = raise_privileges();

300

if(ret != 0){

301

errno = old_errno;

302

return ret;

303

}

304

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

305

ret = errno;

306

}

307

errno = old_errno;

308

return ret;

309

}

310

311

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

312

__attribute__((warn_unused_result))

313

int lower_privileges(void){

314

int old_errno = errno;

315

int ret = 0;

316

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

317

ret = errno;

318

}

319

errno = old_errno;

320

return ret;

321

}

322

323

/* Lower privileges permanently */

324

__attribute__((warn_unused_result))

325

int lower_privileges_permanently(void){

326

int old_errno = errno;

327

int ret = 0;

328

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

329

ret = errno;

330

}

331

errno = old_errno;

332

return ret;

333

}

334

335

247

/*

336

248

* Initialize GPGME.

337

249

*/

338

__attribute__((nonnull, warn_unused_result))

339

static bool init_gpgme(const char * const seckey,

340

const char * const pubkey,

341

const char * const tempdir,

342

mandos_context *mc){

250

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

251

const char *tempdir, mandos_context *mc){

343

252

gpgme_error_t rc;

344

253

gpgme_engine_info_t engine_info;

345

254

346

255

/*

347

256

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

348

257

*/

349

bool import_key(const char * const filename){

258

bool import_key(const char *filename){

350

259

int ret;

351

260

int fd;

352

261

gpgme_data_t pgp_data;

357

266

return false;

358

267

}

359

268

360

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

361

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

362

do {

363

{

364

time_t currtime = time(NULL);

365

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

366

struct tm tm;

367

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

368

perror_plus("gmtime_r");

369

break;

370

}

371

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

372

break;

373

}

374

if(debug){

375

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

376

}

377

} else {

378

if(debug){

379

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

380

}

381

}

382

}

383

struct stat keystat;

384

ret = fstat(fd, &keystat);

385

if(ret != 0){

386

perror_plus("fstat");

387

break;

388

}

389

ret = raise_privileges();

390

if(ret != 0){

391

errno = ret;

392

perror_plus("Failed to raise privileges");

393

break;

394

}

395

if(debug){

396

fprintf_plus(stderr,

397

"Setting system clock to key file mtime");

398

}

399

time_t keytime = keystat.st_mtim.tv_sec;

400

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

401

perror_plus("stime");

402

}

403

ret = lower_privileges();

404

if(ret != 0){

405

errno = ret;

406

perror_plus("Failed to lower privileges");

407

}

408

} while(false);

409

410

269

rc = gpgme_data_new_from_fd(&pgp_data, fd);

411

270

if(rc != GPG_ERR_NO_ERROR){

412

271

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

420

279

gpgme_strsource(rc), gpgme_strerror(rc));

421

280

return false;

422

281

}

423

{

424

gpgme_import_result_t import_result

425

= gpgme_op_import_result(mc->ctx);

426

if((import_result->imported < 1

427

or import_result->not_imported > 0)

428

and import_result->unchanged == 0){

429

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

430

fprintf_plus(stderr,

431

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

432

import_result->considered);

433

fprintf_plus(stderr,

434

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

435

import_result->no_user_id);

436

fprintf_plus(stderr,

437

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

438

import_result->imported);

439

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

440

import_result->imported_rsa);

441

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

442

import_result->unchanged);

443

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

444

import_result->new_user_ids);

445

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

446

import_result->new_sub_keys);

447

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

448

import_result->new_signatures);

449

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

450

import_result->new_revocations);

451

fprintf_plus(stderr,

452

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

453

import_result->secret_read);

454

fprintf_plus(stderr,

455

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

456

import_result->secret_imported);

457

fprintf_plus(stderr,

458

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

459

import_result->secret_unchanged);

460

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

461

import_result->not_imported);

462

for(gpgme_import_status_t import_status

463

= import_result->imports;

464

import_status != NULL;

465

import_status = import_status->next){

466

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

467

import_status->fpr);

468

if(import_status->result != GPG_ERR_NO_ERROR){

469

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

470

gpgme_strsource(import_status->result),

471

gpgme_strerror(import_status->result));

472

}

473

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

474

fprintf_plus(stderr,

475

import_status->status & GPGME_IMPORT_NEW

476

? "The key was new.\n"

477

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

478

fprintf_plus(stderr,

479

import_status->status & GPGME_IMPORT_UID

480

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

481

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

482

fprintf_plus(stderr,

483

import_status->status & GPGME_IMPORT_SIG

484

? "The key contained new signatures.\n"

485

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

486

fprintf_plus(stderr,

487

import_status->status & GPGME_IMPORT_SUBKEY

488

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

489

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

490

fprintf_plus(stderr,

491

import_status->status & GPGME_IMPORT_SECRET

492

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

493

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

494

}

495

return false;

496

}

497

}

498

282

499

ret = close(fd);

283

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

500

284

if(ret == -1){

501

285

perror_plus("close");

502

286

}

541

325

/* Create new GPGME "context" */

542

326

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

543

327

if(rc != GPG_ERR_NO_ERROR){

544

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

545

gpgme_strsource(rc), gpgme_strerror(rc));

328

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

329

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

330

gpgme_strerror(rc));

546

331

return false;

547

332

}

548

333

557

342

* Decrypt OpenPGP data.

558

343

* Returns -1 on error

559

344

*/

560

__attribute__((nonnull, warn_unused_result))

561

345

static ssize_t pgp_packet_decrypt(const char *cryptotext,

562

346

size_t crypto_size,

563

347

char **plaintext,

584

368

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

585

369

rc = gpgme_data_new(&dh_plain);

586

370

if(rc != GPG_ERR_NO_ERROR){

587

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

371

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

372

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

588

373

gpgme_strsource(rc), gpgme_strerror(rc));

589

374

gpgme_data_release(dh_crypto);

590

375

return -1;

603

388

if(result == NULL){

604

389

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

605

390

} else {

606

if(result->unsupported_algorithm != NULL) {

607

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

608

result->unsupported_algorithm);

609

}

610

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

611

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

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);

612

395

if(result->file_name != NULL){

613

396

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

614

397

}

615

616

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

617

r = r->next){

398

gpgme_recipient_t recipient;

399

recipient = result->recipients;

400

while(recipient != NULL){

618

401

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

619

gpgme_pubkey_algo_name(r->pubkey_algo));

620

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

402

gpgme_pubkey_algo_name

403

(recipient->pubkey_algo));

404

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

621

405

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

622

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

406

recipient->status == GPG_ERR_NO_SECKEY

407

? "No" : "Yes");

408

recipient = recipient->next;

623

409

}

624

410

}

625

411

}

681

467

return plaintext_length;

682

468

}

683

469

684

__attribute__((warn_unused_result, const))

685

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

686

if(str == NULL)

687

return "(unknown)";

688

return str;

689

}

690

691

__attribute__((warn_unused_result))

692

static const char *safer_gnutls_strerror(int value){

470

static const char * safer_gnutls_strerror(int value){

693

471

const char *ret = gnutls_strerror(value);

694

return safe_string(ret);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

695

475

}

696

476

697

477

/* GnuTLS log function callback */

698

__attribute__((nonnull))

699

478

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

700

479

const char* string){

701

480

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

702

481

}

703

482

704

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

705

483

static int init_gnutls_global(const char *pubkeyfilename,

706

484

const char *seckeyfilename,

707

const char *dhparamsfilename,

708

485

mandos_context *mc){

709

486

int ret;

710

487

712

489

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

713

490

}

714

491

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

715

499

if(debug){

716

500

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

717

501

* - GnuTLS manual

725

509

if(ret != GNUTLS_E_SUCCESS){

726

510

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

727

511

safer_gnutls_strerror(ret));

512

gnutls_global_deinit();

728

513

return -1;

729

514

}

730

515

731

516

if(debug){

732

fprintf_plus(stderr, "Attempting to use public key %s and"

733

" private key %s as GnuTLS credentials\n",

517

fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"

518

" secret key %s as GnuTLS credentials\n",

734

519

pubkeyfilename,

735

520

seckeyfilename);

736

521

}

737

522

738

#if GNUTLS_VERSION_NUMBER >= 0x030606

739

ret = gnutls_certificate_set_rawpk_key_file

740

(mc->cred, pubkeyfilename, seckeyfilename,

741

GNUTLS_X509_FMT_PEM, /* format */

742

NULL, /* pass */

743

/* key_usage */

744

GNUTLS_KEY_DIGITAL_SIGNATURE | GNUTLS_KEY_KEY_ENCIPHERMENT,

745

NULL, /* names */

746

0, /* names_length */

747

/* privkey_flags */

748

GNUTLS_PKCS_PLAIN | GNUTLS_PKCS_NULL_PASSWORD,

749

0); /* pkcs11_flags */

750

#elif GNUTLS_VERSION_NUMBER < 0x030600

751

523

ret = gnutls_certificate_set_openpgp_key_file

752

524

(mc->cred, pubkeyfilename, seckeyfilename,

753

525

GNUTLS_OPENPGP_FMT_BASE64);

754

#else

755

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

756

#endif

757

526

if(ret != GNUTLS_E_SUCCESS){

758

527

fprintf_plus(stderr,

759

"Error[%d] while reading the key pair ('%s',"

528

"Error[%d] while reading the OpenPGP key pair ('%s',"

760

529

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

761

530

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

762

531

safer_gnutls_strerror(ret));

771

540

safer_gnutls_strerror(ret));

772

541

goto globalfail;

773

542

}

774

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

775

if(dhparamsfilename != NULL){

776

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

777

do {

778

int dhpfile = open(dhparamsfilename, O_RDONLY);

779

if(dhpfile == -1){

780

perror_plus("open");

781

dhparamsfilename = NULL;

782

break;

783

}

784

size_t params_capacity = 0;

785

while(true){

786

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

787

(size_t)params.size,

788

(size_t)params_capacity);

789

if(params_capacity == 0){

790

perror_plus("incbuffer");

791

free(params.data);

792

params.data = NULL;

793

dhparamsfilename = NULL;

794

break;

795

}

796

ssize_t bytes_read = read(dhpfile,

797

params.data + params.size,

798

BUFFER_SIZE);

799

/* EOF */

800

if(bytes_read == 0){

801

break;

802

}

803

/* check bytes_read for failure */

804

if(bytes_read < 0){

805

perror_plus("read");

806

free(params.data);

807

params.data = NULL;

808

dhparamsfilename = NULL;

809

break;

810

}

811

params.size += (unsigned int)bytes_read;

812

}

813

ret = close(dhpfile);

814

if(ret == -1){

815

perror_plus("close");

816

}

817

if(params.data == NULL){

818

dhparamsfilename = NULL;

819

}

820

if(dhparamsfilename == NULL){

821

break;

822

}

823

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

824

GNUTLS_X509_FMT_PEM);

825

if(ret != GNUTLS_E_SUCCESS){

826

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

827

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

828

safer_gnutls_strerror(ret));

829

dhparamsfilename = NULL;

830

}

831

free(params.data);

832

} while(false);

833

}

834

if(dhparamsfilename == NULL){

835

if(mc->dh_bits == 0){

836

#if GNUTLS_VERSION_NUMBER < 0x030600

837

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

838

/* Try to read the private key file */

839

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

840

do {

841

int secfile = open(seckeyfilename, O_RDONLY);

842

if(secfile == -1){

843

perror_plus("open");

844

break;

845

}

846

size_t buffer_capacity = 0;

847

while(true){

848

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

849

(size_t)buffer.size,

850

(size_t)buffer_capacity);

851

if(buffer_capacity == 0){

852

perror_plus("incbuffer");

853

free(buffer.data);

854

buffer.data = NULL;

855

break;

856

}

857

ssize_t bytes_read = read(secfile,

858

buffer.data + buffer.size,

859

BUFFER_SIZE);

860

/* EOF */

861

if(bytes_read == 0){

862

break;

863

}

864

/* check bytes_read for failure */

865

if(bytes_read < 0){

866

perror_plus("read");

867

free(buffer.data);

868

buffer.data = NULL;

869

break;

870

}

871

buffer.size += (unsigned int)bytes_read;

872

}

873

close(secfile);

874

} while(false);

875

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

876

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

877

if(buffer.data != NULL){

878

{

879

gnutls_openpgp_privkey_t privkey = NULL;

880

ret = gnutls_openpgp_privkey_init(&privkey);

881

if(ret != GNUTLS_E_SUCCESS){

882

fprintf_plus(stderr, "Error initializing OpenPGP key"

883

" structure: %s",

884

safer_gnutls_strerror(ret));

885

free(buffer.data);

886

buffer.data = NULL;

887

} else {

888

ret = gnutls_openpgp_privkey_import

889

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

890

if(ret != GNUTLS_E_SUCCESS){

891

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

892

safer_gnutls_strerror(ret));

893

privkey = NULL;

894

}

895

free(buffer.data);

896

buffer.data = NULL;

897

if(privkey != NULL){

898

/* Use private key to suggest an appropriate

899

sec_param */

900

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

901

gnutls_openpgp_privkey_deinit(privkey);

902

if(debug){

903

fprintf_plus(stderr, "This OpenPGP key implies using"

904

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

905

safe_string(gnutls_sec_param_get_name

906

(sec_param)));

907

}

908

}

909

}

910

}

911

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

912

/* Err on the side of caution */

913

sec_param = GNUTLS_SEC_PARAM_ULTRA;

914

if(debug){

915

fprintf_plus(stderr, "Falling back to security parameter"

916

" \"%s\"\n",

917

safe_string(gnutls_sec_param_get_name

918

(sec_param)));

919

}

920

}

921

}

922

unsigned int uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

923

if(uret != 0){

924

mc->dh_bits = uret;

925

if(debug){

926

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

927

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

928

safe_string(gnutls_sec_param_get_name

929

(sec_param)),

930

mc->dh_bits);

931

}

932

} else {

933

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

934

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

935

safe_string(gnutls_sec_param_get_name

936

(sec_param)),

937

safer_gnutls_strerror(ret));

938

goto globalfail;

939

}

940

#endif

941

} else { /* dh_bits != 0 */

942

if(debug){

943

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

944

mc->dh_bits);

945

}

946

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

947

if(ret != GNUTLS_E_SUCCESS){

948

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

949

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

950

safer_gnutls_strerror(ret));

951

goto globalfail;

952

}

953

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

954

}

955

}

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

550

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

956

551

957

552

return 0;

958

553

959

554

globalfail:

960

555

961

556

gnutls_certificate_free_credentials(mc->cred);

557

gnutls_global_deinit();

962

558

gnutls_dh_params_deinit(mc->dh_params);

963

559

return -1;

964

560

}

965

561

966

__attribute__((nonnull, warn_unused_result))

967

562

static int init_gnutls_session(gnutls_session_t *session,

968

563

mandos_context *mc){

969

564

int ret;

970

565

/* GnuTLS session creation */

971

566

do {

972

ret = gnutls_init(session, (GNUTLS_SERVER

973

#if GNUTLS_VERSION_NUMBER >= 0x030506

974

| GNUTLS_NO_TICKETS

975

#endif

976

#if GNUTLS_VERSION_NUMBER >= 0x030606

977

| GNUTLS_ENABLE_RAWPK

978

#endif

979

));

567

ret = gnutls_init(session, GNUTLS_SERVER);

980

568

if(quit_now){

981

569

return -1;

982

570

}

1023

611

/* ignore client certificate if any. */

1024

612

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

1025

613

614

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

1026

616

return 0;

1027

617

}

1028

618

1030

620

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

1031

621

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

1032

622

1033

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

1034

__attribute__((nonnull, warn_unused_result))

1035

static bool add_delete_local_route(const bool add,

1036

const char *address,

1037

AvahiIfIndex if_index){

1038

int ret;

1039

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

1040

char add_arg[] = "add";

1041

char delete_arg[] = "delete";

1042

char debug_flag[] = "--debug";

1043

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

1044

if(pluginhelperdir == NULL){

1045

if(debug){

1046

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

1047

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

1048

}

1049

return false;

1050

}

1051

1052

char interface[IF_NAMESIZE];

1053

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

1054

perror_plus("if_indextoname");

1055

return false;

1056

}

1057

1058

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

1059

if(devnull == -1){

1060

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

1061

return false;

1062

}

1063

pid_t pid = fork();

1064

if(pid == 0){

1065

/* Child */

1066

/* Raise privileges */

1067

errno = raise_privileges_permanently();

1068

if(errno != 0){

1069

perror_plus("Failed to raise privileges");

1070

/* _exit(EX_NOPERM); */

1071

} else {

1072

/* Set group */

1073

errno = 0;

1074

ret = setgid(0);

1075

if(ret == -1){

1076

perror_plus("setgid");

1077

_exit(EX_NOPERM);

1078

}

1079

/* Reset supplementary groups */

1080

errno = 0;

1081

ret = setgroups(0, NULL);

1082

if(ret == -1){

1083

perror_plus("setgroups");

1084

_exit(EX_NOPERM);

1085

}

1086

}

1087

ret = dup2(devnull, STDIN_FILENO);

1088

if(ret == -1){

1089

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

1090

_exit(EX_OSERR);

1091

}

1092

ret = close(devnull);

1093

if(ret == -1){

1094

perror_plus("close");

1095

_exit(EX_OSERR);

1096

}

1097

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1098

if(ret == -1){

1099

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

1100

_exit(EX_OSERR);

1101

}

1102

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

1103

O_RDONLY

1104

| O_DIRECTORY

1105

| O_PATH

1106

| O_CLOEXEC));

1107

if(helperdir_fd == -1){

1108

perror_plus("open");

1109

_exit(EX_UNAVAILABLE);

1110

}

1111

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

1112

helper, O_RDONLY));

1113

if(helper_fd == -1){

1114

perror_plus("openat");

1115

close(helperdir_fd);

1116

_exit(EX_UNAVAILABLE);

1117

}

1118

close(helperdir_fd);

1119

#ifdef __GNUC__

1120

#pragma GCC diagnostic push

1121

#pragma GCC diagnostic ignored "-Wcast-qual"

1122

#endif

1123

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

1124

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

1125

interface, debug ? debug_flag : NULL, NULL },

1126

environ) == -1){

1127

#ifdef __GNUC__

1128

#pragma GCC diagnostic pop

1129

#endif

1130

perror_plus("fexecve");

1131

_exit(EXIT_FAILURE);

1132

}

1133

}

1134

if(pid == -1){

1135

perror_plus("fork");

1136

return false;

1137

}

1138

int status;

1139

pid_t pret = -1;

1140

errno = 0;

1141

do {

1142

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

1143

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

1144

int errno_raising = 0;

1145

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

1146

errno_raising = errno;

1147

perror_plus("Failed to raise privileges in order to"

1148

" kill helper program");

1149

}

1150

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

1151

perror_plus("kill");

1152

}

1153

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

1154

perror_plus("Failed to lower privileges after killing"

1155

" helper program");

1156

}

1157

return false;

1158

}

1159

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

1160

if(pret == -1){

1161

perror_plus("waitpid");

1162

return false;

1163

}

1164

if(WIFEXITED(status)){

1165

if(WEXITSTATUS(status) != 0){

1166

fprintf_plus(stderr, "Error: iprouteadddel exited"

1167

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

1168

return false;

1169

}

1170

return true;

1171

}

1172

if(WIFSIGNALED(status)){

1173

fprintf_plus(stderr, "Error: iprouteadddel died by"

1174

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

1175

return false;

1176

}

1177

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

1178

return false;

1179

}

1180

1181

__attribute__((nonnull, warn_unused_result))

1182

static bool add_local_route(const char *address,

1183

AvahiIfIndex if_index){

1184

if(debug){

1185

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

1186

}

1187

return add_delete_local_route(true, address, if_index);

1188

}

1189

1190

__attribute__((nonnull, warn_unused_result))

1191

static bool delete_local_route(const char *address,

1192

AvahiIfIndex if_index){

1193

if(debug){

1194

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

1195

}

1196

return add_delete_local_route(false, address, if_index);

1197

}

1198

1199

623

/* Called when a Mandos server is found */

1200

__attribute__((nonnull, warn_unused_result))

1201

624

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

1202

625

AvahiIfIndex if_index,

1203

626

int af, mandos_context *mc){

1204

627

int ret, tcp_sd = -1;

1205

628

ssize_t sret;

1206

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1207

633

char *buffer = NULL;

1208

634

char *decrypted_buffer = NULL;

1209

635

size_t buffer_length = 0;

1212

638

int retval = -1;

1213

639

gnutls_session_t session;

1214

640

int pf; /* Protocol family */

1215

bool route_added = false;

1216

641

1217

642

errno = 0;

1218

643

1234

659

return -1;

1235

660

}

1236

661

1237

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

1238

662

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

1239

663

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

1240

664

bool match = false;

1241

665

{

1242

666

char *interface = NULL;

1243

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

1244

mc->interfaces_size,

1245

interface))){

667

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

668

interface))){

1246

669

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

1247

670

match = true;

1248

671

break;

1250

673

}

1251

674

}

1252

675

if(not match){

1253

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

1254

connect to the server */

1255

676

if(debug){

1256

677

char interface[IF_NAMESIZE];

1257

678

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

1277

698

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

1278

699

}

1279

700

1280

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

701

tcp_sd = socket(pf, SOCK_STREAM, 0);

1281

702

if(tcp_sd < 0){

1282

703

int e = errno;

1283

704

perror_plus("socket");

1290

711

goto mandos_end;

1291

712

}

1292

713

714

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

1293

715

if(af == AF_INET6){

1294

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

1295

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

1296

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

716

to.in6.sin6_family = (sa_family_t)af;

717

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

1297

718

} else { /* IPv4 */

1298

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

1299

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

1300

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

719

to.in.sin_family = (sa_family_t)af;

720

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

1301

721

}

1302

722

if(ret < 0 ){

1303

723

int e = errno;

1312

732

goto mandos_end;

1313

733

}

1314

734

if(af == AF_INET6){

1315

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

1316

if(IN6_IS_ADDR_LINKLOCAL

1317

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

735

to.in6.sin6_port = htons(port);

736

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

737

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

738

-Wunreachable-code*/

1318

739

if(if_index == AVAHI_IF_UNSPEC){

1319

740

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

1320

741

" incomplete without a network interface\n");

1322

743

goto mandos_end;

1323

744

}

1324

745

/* Set the network interface number as scope */

1325

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

746

to.in6.sin6_scope_id = (uint32_t)if_index;

1326

747

}

1327

748

} else {

1328

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

749

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

750

-Wconversion and

751

-Wunreachable-code */

1329

752

}

1330

753

1331

754

if(quit_now){

1348

771

}

1349

772

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1350

773

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1351

if(af == AF_INET6){

1352

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

1353

sizeof(struct sockaddr_in6),

1354

addrstr, sizeof(addrstr), NULL, 0,

1355

NI_NUMERICHOST);

1356

} else {

1357

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

1358

sizeof(struct sockaddr_in),

1359

addrstr, sizeof(addrstr), NULL, 0,

1360

NI_NUMERICHOST);

1361

}

1362

if(ret == EAI_SYSTEM){

1363

perror_plus("getnameinfo");

1364

} else if(ret != 0) {

1365

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

1366

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

1367

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

1368

}

1369

}

1370

1371

if(quit_now){

1372

errno = EINTR;

1373

goto mandos_end;

1374

}

1375

1376

while(true){

1377

if(af == AF_INET6){

1378

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

1379

sizeof(struct sockaddr_in6));

1380

} else {

1381

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

1382

sizeof(struct sockaddr_in));

1383

}

1384

if(ret < 0){

1385

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

1386

and if_index != AVAHI_IF_UNSPEC

1387

and connect_to == NULL

1388

and not route_added and

1389

((af == AF_INET6 and not

1390

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1391

&to)->sin6_addr)))

1392

or (af == AF_INET and

1393

/* Not a a IPv4LL address */

1394

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

1395

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

1396

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

1397

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

1398

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

1399

connect to a Mandos server announced by Avahi on a server

1400

host with a global address. Work around this by retrying

1401

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

1402

1403

Avahi bug reference:

1404

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

1405

https://bugs.debian.org/587961

1406

*/

1407

if(debug){

1408

fprintf_plus(stderr, "Mandos server unreachable, trying"

1409

" direct route\n");

1410

}

1411

int e = errno;

1412

route_added = add_local_route(ip, if_index);

1413

if(route_added){

1414

continue;

1415

}

1416

errno = e;

1417

}

1418

if(errno != ECONNREFUSED or debug){

1419

int e = errno;

1420

perror_plus("connect");

1421

errno = e;

1422

}

1423

goto mandos_end;

1424

}

1425

1426

if(quit_now){

1427

errno = EINTR;

1428

goto mandos_end;

1429

}

1430

break;

774

const char *pcret;

775

if(af == AF_INET6){

776

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

777

sizeof(addrstr));

778

} else {

779

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

780

sizeof(addrstr));

781

}

782

if(pcret == NULL){

783

perror_plus("inet_ntop");

784

} else {

785

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

786

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

787

}

788

}

789

}

790

791

if(quit_now){

792

errno = EINTR;

793

goto mandos_end;

794

}

795

796

if(af == AF_INET6){

797

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

798

} else {

799

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

800

}

801

if(ret < 0){

802

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

803

int e = errno;

804

perror_plus("connect");

805

errno = e;

806

}

807

goto mandos_end;

808

}

809

810

if(quit_now){

811

errno = EINTR;

812

goto mandos_end;

1431

813

}

1432

814

1433

815

const char *out = mandos_protocol_version;

1587

969

&decrypted_buffer, mc);

1588

970

if(decrypted_buffer_size >= 0){

1589

971

1590

clearerr(stdout);

1591

972

written = 0;

1592

973

while(written < (size_t) decrypted_buffer_size){

1593

974

if(quit_now){

1609

990

}

1610

991

written += (size_t)ret;

1611

992

}

1612

ret = fflush(stdout);

1613

if(ret != 0){

1614

int e = errno;

1615

if(debug){

1616

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

1617

strerror(errno));

1618

}

1619

errno = e;

1620

goto mandos_end;

1621

}

1622

993

retval = 0;

1623

994

}

1624

995

}

1627

998

1628

999

mandos_end:

1629

1000

{

1630

if(route_added){

1631

if(not delete_local_route(ip, if_index)){

1632

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

1633

" interface %d", ip, if_index);

1634

}

1635

}

1636

1001

int e = errno;

1637

1002

free(decrypted_buffer);

1638

1003

free(buffer);

1639

1004

if(tcp_sd >= 0){

1640

ret = close(tcp_sd);

1005

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

1641

1006

}

1642

1007

if(ret == -1){

1643

1008

if(e == 0){

1668

1033

AVAHI_GCC_UNUSED AvahiStringList *txt,

1669

1034

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1670

1035

flags,

1671

void *mc){

1036

void* mc){

1672

1037

if(r == NULL){

1673

1038

return;

1674

1039

}

1677

1042

timed out */

1678

1043

1679

1044

if(quit_now){

1680

avahi_s_service_resolver_free(r);

1681

1045

return;

1682

1046

}

1683

1047

1728

1092

const char *domain,

1729

1093

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1730

1094

flags,

1731

void *mc){

1095

void* mc){

1732

1096

if(b == NULL){

1733

1097

return;

1734

1098

}

1794

1158

errno = old_errno;

1795

1159

}

1796

1160

1797

__attribute__((nonnull, warn_unused_result))

1798

1161

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

1799

1162

int ret;

1800

int old_errno;

1163

error_t ret_errno;

1801

1164

1802

1165

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

1803

1166

if(s < 0){

1804

old_errno = errno;

1167

ret_errno = errno;

1805

1168

perror_plus("socket");

1806

errno = old_errno;

1169

errno = ret_errno;

1807

1170

return false;

1808

1171

}

1809

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

1810

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

1172

strcpy(ifr->ifr_name, ifname);

1811

1173

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1812

1174

if(ret == -1){

1813

1175

if(debug){

1814

old_errno = errno;

1176

ret_errno = errno;

1815

1177

perror_plus("ioctl SIOCGIFFLAGS");

1816

errno = old_errno;

1817

}

1818

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

1819

old_errno = errno;

1820

perror_plus("close");

1821

errno = old_errno;

1178

errno = ret_errno;

1822

1179

}

1823

1180

return false;

1824

1181

}

1825

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

1826

old_errno = errno;

1827

perror_plus("close");

1828

errno = old_errno;

1829

}

1830

1182

return true;

1831

1183

}

1832

1184

1833

__attribute__((nonnull, warn_unused_result))

1834

1185

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

1835

1186

1836

1187

/* Reject the loopback device */

1878

1229

* corresponds to an acceptable network device.

1879

1230

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

1880

1231

*/

1881

__attribute__((nonnull, warn_unused_result))

1882

1232

int good_interface(const struct dirent *if_entry){

1883

1233

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

1884

1234

return 0;

1902

1252

/*

1903

1253

* This function determines if a network interface is up.

1904

1254

*/

1905

__attribute__((nonnull, warn_unused_result))

1906

1255

bool interface_is_up(const char *interface){

1907

1256

struct ifreq ifr;

1908

1257

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

1919

1268

/*

1920

1269

* This function determines if a network interface is running

1921

1270

*/

1922

__attribute__((nonnull, warn_unused_result))

1923

1271

bool interface_is_running(const char *interface){

1924

1272

struct ifreq ifr;

1925

1273

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

1933

1281

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

1934

1282

}

1935

1283

1936

__attribute__((nonnull, pure, warn_unused_result))

1937

1284

int notdotentries(const struct dirent *direntry){

1938

1285

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

1939

1286

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

1946

1293

}

1947

1294

1948

1295

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

1949

__attribute__((nonnull, warn_unused_result))

1950

1296

int runnable_hook(const struct dirent *direntry){

1951

1297

int ret;

1952

1298

size_t sret;

1960

1306

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

1961

1307

"abcdefghijklmnopqrstuvwxyz"

1962

1308

"0123456789"

1963

"_.-");

1309

"_-");

1964

1310

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

1965

1311

/* Contains non-allowed characters */

1966

1312

if(debug){

1970

1316

return 0;

1971

1317

}

1972

1318

1973

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

1319

char *fullname = NULL;

1320

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

1321

if(ret < 0){

1322

perror_plus("asprintf");

1323

return 0;

1324

}

1325

1326

ret = stat(fullname, &st);

1974

1327

if(ret == -1){

1975

1328

if(debug){

1976

1329

perror_plus("Could not stat hook");

2000

1353

return 1;

2001

1354

}

2002

1355

2003

__attribute__((nonnull, warn_unused_result))

2004

1356

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

2005

1357

mandos_context *mc){

2006

1358

int ret;

2010

1362

2011

1363

while(true){

2012

1364

if(mc->current_server == NULL){

2013

if(debug){

1365

if (debug){

2014

1366

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

2015

1367

" No timeout!\n");

2016

1368

}

2017

1369

ret = avahi_simple_poll_iterate(s, -1);

2018

1370

} else {

2019

if(debug){

1371

if (debug){

2020

1372

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

2021

1373

" it, or wait\n");

2022

1374

}

2039

1391

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

2040

1392

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

2041

1393

2042

if(debug){

1394

if (debug){

2043

1395

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

2044

1396

block_time);

2045

1397

}

2067

1419

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

2068

1420

}

2069

1421

if(ret != 0){

2070

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

1422

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

2071

1423

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

2072

1424

}

2073

1425

}

2074

1426

}

2075

1427

}

2076

1428

2077

__attribute__((nonnull))

2078

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

1429

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

1430

error_t raise_privileges(void){

1431

error_t old_errno = errno;

1432

error_t ret_errno = 0;

1433

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

1434

ret_errno = errno;

1435

perror_plus("seteuid");

1436

}

1437

errno = old_errno;

1438

return ret_errno;

1439

}

1440

1441

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

1442

error_t raise_privileges_permanently(void){

1443

error_t old_errno = errno;

1444

error_t ret_errno = raise_privileges();

1445

if(ret_errno != 0){

1446

errno = old_errno;

1447

return ret_errno;

1448

}

1449

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

1450

ret_errno = errno;

1451

perror_plus("seteuid");

1452

}

1453

errno = old_errno;

1454

return ret_errno;

1455

}

1456

1457

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

1458

error_t lower_privileges(void){

1459

error_t old_errno = errno;

1460

error_t ret_errno = 0;

1461

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

1462

ret_errno = errno;

1463

perror_plus("seteuid");

1464

}

1465

errno = old_errno;

1466

return ret_errno;

1467

}

1468

1469

/* Lower privileges permanently */

1470

error_t lower_privileges_permanently(void){

1471

error_t old_errno = errno;

1472

error_t ret_errno = 0;

1473

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

1474

ret_errno = errno;

1475

perror_plus("setuid");

1476

}

1477

errno = old_errno;

1478

return ret_errno;

1479

}

1480

1481

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

2079

1482

const float delay){

2080

struct dirent **direntries = NULL;

2081

if(hookdir_fd == -1){

2082

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

2083

| O_CLOEXEC);

2084

if(hookdir_fd == -1){

2085

if(errno == ENOENT){

2086

if(debug){

2087

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

2088

" found\n", hookdir);

2089

}

2090

} else {

2091

perror_plus("open");

2092

}

2093

return;

2094

}

2095

}

2096

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

2097

if(devnull == -1){

2098

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

2099

return;

2100

}

2101

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

2102

runnable_hook, alphasort);

1483

struct dirent **direntries;

1484

struct dirent *direntry;

1485

int ret;

1486

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

1487

alphasort);

2103

1488

if(numhooks == -1){

2104

perror_plus("scandir");

2105

close(devnull);

2106

return;

2107

}

2108

struct dirent *direntry;

2109

int ret;

2110

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

2111

direntry = direntries[i];

2112

if(debug){

2113

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

2114

direntry->d_name);

1489

if(errno == ENOENT){

1490

if(debug){

1491

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

1492

" found\n", hookdir);

1493

}

1494

} else {

1495

perror_plus("scandir");

2115

1496

}

2116

pid_t hook_pid = fork();

2117

if(hook_pid == 0){

2118

/* Child */

2119

/* Raise privileges */

2120

errno = raise_privileges_permanently();

2121

if(errno != 0){

2122

perror_plus("Failed to raise privileges");

2123

_exit(EX_NOPERM);

2124

}

2125

/* Set group */

2126

errno = 0;

2127

ret = setgid(0);

2128

if(ret == -1){

2129

perror_plus("setgid");

2130

_exit(EX_NOPERM);

2131

}

2132

/* Reset supplementary groups */

2133

errno = 0;

2134

ret = setgroups(0, NULL);

2135

if(ret == -1){

2136

perror_plus("setgroups");

2137

_exit(EX_NOPERM);

2138

}

2139

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

2140

if(ret == -1){

2141

perror_plus("setenv");

2142

_exit(EX_OSERR);

2143

}

2144

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

2145

if(ret == -1){

2146

perror_plus("setenv");

2147

_exit(EX_OSERR);

2148

}

2149

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

2150

if(ret == -1){

2151

perror_plus("setenv");

2152

_exit(EX_OSERR);

2153

}

2154

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

2155

if(ret == -1){

2156

perror_plus("setenv");

2157

_exit(EX_OSERR);

2158

}

2159

char *delaystring;

2160

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

2161

if(ret == -1){

1497

} else {

1498

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

1499

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

1500

direntry = direntries[i];

1501

char *fullname = NULL;

1502

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

1503

if(ret < 0){

2162

1504

perror_plus("asprintf");

2163

_exit(EX_OSERR);

2164

}

2165

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

2166

if(ret == -1){

1505

continue;

1506

}

1507

if(debug){

1508

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

1509

direntry->d_name);

1510

}

1511

pid_t hook_pid = fork();

1512

if(hook_pid == 0){

1513

/* Child */

1514

/* Raise privileges */

1515

raise_privileges_permanently();

1516

/* Set group */

1517

errno = 0;

1518

ret = setgid(0);

1519

if(ret == -1){

1520

perror_plus("setgid");

1521

}

1522

/* Reset supplementary groups */

1523

errno = 0;

1524

ret = setgroups(0, NULL);

1525

if(ret == -1){

1526

perror_plus("setgroups");

1527

}

1528

dup2(devnull, STDIN_FILENO);

1529

close(devnull);

1530

dup2(STDERR_FILENO, STDOUT_FILENO);

1531

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

1532

if(ret == -1){

1533

perror_plus("setenv");

1534

_exit(EX_OSERR);

1535

}

1536

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

1537

if(ret == -1){

1538

perror_plus("setenv");

1539

_exit(EX_OSERR);

1540

}

1541

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

1542

if(ret == -1){

1543

perror_plus("setenv");

1544

_exit(EX_OSERR);

1545

}

1546

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

1547

if(ret == -1){

1548

perror_plus("setenv");

1549

_exit(EX_OSERR);

1550

}

1551

char *delaystring;

1552

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

1553

if(ret == -1){

1554

perror_plus("asprintf");

1555

_exit(EX_OSERR);

1556

}

1557

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

1558

if(ret == -1){

1559

free(delaystring);

1560

perror_plus("setenv");

1561

_exit(EX_OSERR);

1562

}

2167

1563

free(delaystring);

2168

perror_plus("setenv");

2169

_exit(EX_OSERR);

2170

}

2171

free(delaystring);

2172

if(connect_to != NULL){

2173

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

2174

if(ret == -1){

2175

perror_plus("setenv");

2176

_exit(EX_OSERR);

2177

}

2178

}

2179

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

2180

direntry->d_name,

2181

O_RDONLY));

2182

if(hook_fd == -1){

2183

perror_plus("openat");

2184

_exit(EXIT_FAILURE);

2185

}

2186

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

2187

perror_plus("close");

2188

_exit(EXIT_FAILURE);

2189

}

2190

ret = dup2(devnull, STDIN_FILENO);

2191

if(ret == -1){

2192

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

2193

_exit(EX_OSERR);

2194

}

2195

ret = close(devnull);

2196

if(ret == -1){

2197

perror_plus("close");

2198

_exit(EX_OSERR);

2199

}

2200

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2201

if(ret == -1){

2202

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

2203

_exit(EX_OSERR);

2204

}

2205

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

2206

environ) == -1){

2207

perror_plus("fexecve");

2208

_exit(EXIT_FAILURE);

2209

}

2210

} else {

2211

if(hook_pid == -1){

2212

perror_plus("fork");

2213

free(direntry);

2214

continue;

2215

}

2216

int status;

2217

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

2218

perror_plus("waitpid");

2219

free(direntry);

2220

continue;

2221

}

2222

if(WIFEXITED(status)){

2223

if(WEXITSTATUS(status) != 0){

2224

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

2225

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

2226

WEXITSTATUS(status));

2227

free(direntry);

2228

continue;

2229

}

2230

} else if(WIFSIGNALED(status)){

2231

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

2232

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

2233

WTERMSIG(status));

2234

free(direntry);

2235

continue;

1564

if(connect_to != NULL){

1565

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

1566

if(ret == -1){

1567

perror_plus("setenv");

1568

_exit(EX_OSERR);

1569

}

1570

}

1571

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

1572

perror_plus("execl");

1573

_exit(EXIT_FAILURE);

1574

}

2236

1575

} else {

2237

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

2238

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

2239

free(direntry);

2240

continue;

2241

}

2242

}

2243

if(debug){

2244

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

2245

direntry->d_name);

2246

}

2247

free(direntry);

2248

}

2249

free(direntries);

2250

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

2251

perror_plus("close");

2252

} else {

2253

hookdir_fd = -1;

2254

}

2255

close(devnull);

1576

int status;

1577

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

1578

perror_plus("waitpid");

1579

free(fullname);

1580

continue;

1581

}

1582

if(WIFEXITED(status)){

1583

if(WEXITSTATUS(status) != 0){

1584

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

1585

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

1586

WEXITSTATUS(status));

1587

free(fullname);

1588

continue;

1589

}

1590

} else if(WIFSIGNALED(status)){

1591

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

1592

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

1593

WTERMSIG(status));

1594

free(fullname);

1595

continue;

1596

} else {

1597

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

1598

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

1599

free(fullname);

1600

continue;

1601

}

1602

}

1603

free(fullname);

1604

if(debug){

1605

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

1606

direntry->d_name);

1607

}

1608

}

1609

close(devnull);

1610

}

1611

return true;

2256

1612

}

2257

1613

2258

__attribute__((nonnull, warn_unused_result))

2259

int bring_up_interface(const char *const interface,

2260

const float delay){

2261

int old_errno = errno;

2262

int ret;

1614

error_t bring_up_interface(const char *const interface,

1615

const float delay){

1616

int sd = -1;

1617

error_t old_errno = errno;

1618

error_t ret_errno = 0;

1619

int ret, ret_setflags;

2263

1620

struct ifreq network;

2264

1621

unsigned int if_index = if_nametoindex(interface);

2265

1622

if(if_index == 0){

2274

1631

}

2275

1632

2276

1633

if(not interface_is_up(interface)){

2277

int ret_errno = 0;

2278

int ioctl_errno = 0;

2279

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

1634

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

2280

1635

ret_errno = errno;

2281

1636

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

2282

1637

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

2283

errno = old_errno;

2284

1638

return ret_errno;

2285

1639

}

2286

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

1640

network.ifr_flags |= IFF_UP;

2287

1641

2288

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

2289

if(sd == -1){

1642

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1643

if(sd < 0){

2290

1644

ret_errno = errno;

2291

1645

perror_plus("socket");

2292

1646

errno = old_errno;

2293

1647

return ret_errno;

2294

1648

}

2295

1649

2296

1650

if(quit_now){

2297

ret = close(sd);

2298

if(ret == -1){

2299

perror_plus("close");

2300

}

1651

close(sd);

2301

1652

errno = old_errno;

2302

1653

return EINTR;

2303

1654

}

2307

1658

interface);

2308

1659

}

2309

1660

2310

/* Raise privileges */

2311

ret_errno = raise_privileges();

2312

if(ret_errno != 0){

2313

errno = ret_errno;

2314

perror_plus("Failed to raise privileges");

2315

}

1661

/* Raise priviliges */

1662

raise_privileges();

2316

1663

2317

1664

#ifdef __linux__

2318

int ret_linux;

2319

bool restore_loglevel = false;

2320

if(ret_errno == 0){

2321

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2322

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

2323

ret_linux = klogctl(8, NULL, 5);

2324

if(ret_linux == -1){

2325

perror_plus("klogctl");

2326

} else {

2327

restore_loglevel = true;

2328

}

1665

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1666

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

1667

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

1668

bool restore_loglevel = true;

1669

if(ret_linux == -1){

1670

restore_loglevel = false;

1671

perror_plus("klogctl");

2329

1672

}

2330

1673

#endif /* __linux__ */

2331

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

2332

ioctl_errno = errno;

1674

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

1675

ret_errno = errno;

2333

1676

#ifdef __linux__

2334

1677

if(restore_loglevel){

2335

1678

ret_linux = klogctl(7, NULL, 0);

2339

1682

}

2340

1683

#endif /* __linux__ */

2341

1684

2342

/* If raise_privileges() succeeded above */

2343

if(ret_errno == 0){

2344

/* Lower privileges */

2345

ret_errno = lower_privileges();

2346

if(ret_errno != 0){

2347

errno = ret_errno;

2348

perror_plus("Failed to lower privileges");

2349

}

2350

}

1685

/* Lower privileges */

1686

lower_privileges();

2351

1687

2352

1688

/* Close the socket */

2353

ret = close(sd);

1689

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

2354

1690

if(ret == -1){

2355

1691

perror_plus("close");

2356

1692

}

2357

1693

2358

1694

if(ret_setflags == -1){

2359

errno = ioctl_errno;

1695

errno = ret_errno;

2360

1696

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2361

1697

errno = old_errno;

2362

return ioctl_errno;

1698

return ret_errno;

2363

1699

}

2364

1700

} else if(debug){

2365

1701

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

2368

1704

2369

1705

/* Sleep checking until interface is running.

2370

1706

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

2371

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

1707

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

2372

1708

if(interface_is_running(interface)){

2373

1709

break;

2374

1710

}

2383

1719

return 0;

2384

1720

}

2385

1721

2386

__attribute__((nonnull, warn_unused_result))

2387

int take_down_interface(const char *const interface){

2388

int old_errno = errno;

1722

error_t take_down_interface(const char *const interface){

1723

int sd = -1;

1724

error_t old_errno = errno;

1725

error_t ret_errno = 0;

1726

int ret, ret_setflags;

2389

1727

struct ifreq network;

2390

1728

unsigned int if_index = if_nametoindex(interface);

2391

1729

if(if_index == 0){

2394

1732

return ENXIO;

2395

1733

}

2396

1734

if(interface_is_up(interface)){

2397

int ret_errno = 0;

2398

int ioctl_errno = 0;

2399

1735

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

2400

1736

ret_errno = errno;

2401

1737

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

2402

1738

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

2403

errno = old_errno;

2404

1739

return ret_errno;

2405

1740

}

2406

1741

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

2407

1742

2408

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

2409

if(sd == -1){

1743

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1744

if(sd < 0){

2410

1745

ret_errno = errno;

2411

1746

perror_plus("socket");

2412

1747

errno = old_errno;

2418

1753

interface);

2419

1754

}

2420

1755

2421

/* Raise privileges */

2422

ret_errno = raise_privileges();

2423

if(ret_errno != 0){

2424

errno = ret_errno;

2425

perror_plus("Failed to raise privileges");

2426

}

2427

2428

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

2429

ioctl_errno = errno;

2430

2431

/* If raise_privileges() succeeded above */

2432

if(ret_errno == 0){

2433

/* Lower privileges */

2434

ret_errno = lower_privileges();

2435

if(ret_errno != 0){

2436

errno = ret_errno;

2437

perror_plus("Failed to lower privileges");

2438

}

2439

}

1756

/* Raise priviliges */

1757

raise_privileges();

1758

1759

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

1760

ret_errno = errno;

1761

1762

/* Lower privileges */

1763

lower_privileges();

2440

1764

2441

1765

/* Close the socket */

2442

int ret = close(sd);

1766

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

2443

1767

if(ret == -1){

2444

1768

perror_plus("close");

2445

1769

}

2446

1770

2447

1771

if(ret_setflags == -1){

2448

errno = ioctl_errno;

1772

errno = ret_errno;

2449

1773

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2450

1774

errno = old_errno;

2451

return ioctl_errno;

1775

return ret_errno;

2452

1776

}

2453

1777

} else if(debug){

2454

1778

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

2460

1784

}

2461

1785

2462

1786

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

2463

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

2464

#if GNUTLS_VERSION_NUMBER >= 0x030606

2465

.priority = "SECURE128:!CTYPE-X.509"

2466

":+CTYPE-RAWPK:!RSA:!VERS-ALL:+VERS-TLS1.3"

2467

":%PROFILE_ULTRA",

2468

#elif GNUTLS_VERSION_NUMBER < 0x030600

2469

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

2470

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

2471

#else

2472

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

2473

#endif

2474

.current_server = NULL, .interfaces = NULL,

2475

.interfaces_size = 0 };

1787

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

1788

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

1789

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

1790

.interfaces = NULL, .interfaces_size = 0 };

2476

1791

AvahiSServiceBrowser *sb = NULL;

2477

1792

error_t ret_errno;

2478

1793

int ret;

2481

1796

int exitcode = EXIT_SUCCESS;

2482

1797

char *interfaces_to_take_down = NULL;

2483

1798

size_t interfaces_to_take_down_size = 0;

2484

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

2485

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

2486

char *tempdir = NULL;

1799

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

1800

bool tempdir_created = false;

2487

1801

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2488

1802

const char *seckey = PATHDIR "/" SECKEY;

2489

1803

const char *pubkey = PATHDIR "/" PUBKEY;

2490

#if GNUTLS_VERSION_NUMBER >= 0x030606

2491

const char *tls_privkey = PATHDIR "/" TLS_PRIVKEY;

2492

const char *tls_pubkey = PATHDIR "/" TLS_PUBKEY;

2493

#endif

2494

const char *dh_params_file = NULL;

2495

1804

char *interfaces_hooks = NULL;

1805

size_t interfaces_hooks_size = 0;

2496

1806

2497

1807

bool gnutls_initialized = false;

2498

1808

bool gpgme_initialized = false;

2544

1854

{ .name = "pubkey", .key = 'p',

2545

1855

.arg = "FILE",

2546

1856

.doc = "OpenPGP public key file base name",

2547

.group = 1 },

2548

{ .name = "tls-privkey", .key = 't',

2549

.arg = "FILE",

2550

#if GNUTLS_VERSION_NUMBER >= 0x030606

2551

.doc = "TLS private key file base name",

2552

#else

2553

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2554

#endif

2555

.group = 1 },

2556

{ .name = "tls-pubkey", .key = 'T',

2557

.arg = "FILE",

2558

#if GNUTLS_VERSION_NUMBER >= 0x030606

2559

.doc = "TLS public key file base name",

2560

#else

2561

.doc = "Dummy; ignored (requires GnuTLS 3.6.6)",

2562

#endif

2563

.group = 1 },

1857

.group = 2 },

2564

1858

{ .name = "dh-bits", .key = 129,

2565

1859

.arg = "BITS",

2566

1860

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

2567

1861

" Diffie-Hellman key exchange",

2568

1862

.group = 2 },

2569

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

2570

.arg = "FILE",

2571

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

2572

" for the Diffie-Hellman key exchange",

2573

.group = 2 },

2574

1863

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

2575

1864

.arg = "STRING",

2576

1865

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

2622

1911

case 'p': /* --pubkey */

2623

1912

pubkey = arg;

2624

1913

break;

2625

case 't': /* --tls-privkey */

2626

#if GNUTLS_VERSION_NUMBER >= 0x030606

2627

tls_privkey = arg;

2628

#endif

2629

break;

2630

case 'T': /* --tls-pubkey */

2631

#if GNUTLS_VERSION_NUMBER >= 0x030606

2632

tls_pubkey = arg;

2633

#endif

2634

break;

2635

1914

case 129: /* --dh-bits */

2636

1915

errno = 0;

2637

1916

tmpmax = strtoimax(arg, &tmp, 10);

2641

1920

}

2642

1921

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

2643

1922

break;

2644

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

2645

dh_params_file = arg;

2646

break;

2647

1923

case 130: /* --priority */

2648

1924

mc.priority = arg;

2649

1925

break;

2672

1948

argp_state_help(state, state->out_stream,

2673

1949

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

2674

1950

& ~(unsigned int)ARGP_HELP_EXIT_OK);

2675

__builtin_unreachable();

2676

1951

case -3: /* --usage */

2677

1952

argp_state_help(state, state->out_stream,

2678

1953

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2679

__builtin_unreachable();

2680

1954

case 'V': /* --version */

2681

1955

fprintf_plus(state->out_stream, "%s\n", argp_program_version);

2682

1956

exit(argp_err_exit_status);

2691

1965

.args_doc = "",

2692

1966

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

2693

1967

" passwords from a Mandos server" };

2694

ret_errno = argp_parse(&argp, argc, argv,

2695

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2696

switch(ret_errno){

1968

ret = argp_parse(&argp, argc, argv,

1969

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1970

switch(ret){

2697

1971

case 0:

2698

1972

break;

2699

1973

case ENOMEM:

2700

1974

default:

2701

errno = ret_errno;

1975

errno = ret;

2702

1976

perror_plus("argp_parse");

2703

1977

exitcode = EX_OSERR;

2704

1978

goto end;

2707

1981

goto end;

2708

1982

}

2709

1983

}

2710

1984

2711

1985

{

2712

1986

/* Work around Debian bug #633582:

2713

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

1987

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

2714

1988

2715

/* Re-raise privileges */

2716

ret = raise_privileges();

2717

if(ret != 0){

2718

errno = ret;

2719

perror_plus("Failed to raise privileges");

2720

} else {

1989

/* Re-raise priviliges */

1990

if(raise_privileges() == 0){

2721

1991

struct stat st;

2722

1992

2723

1993

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

2737

2007

}

2738

2008

}

2739

2009

}

2740

close(seckey_fd);

2010

TEMP_FAILURE_RETRY(close(seckey_fd));

2741

2011

}

2742

2012

}

2743

2013

2744

2014

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

2745

2015

int pubkey_fd = open(pubkey, O_RDONLY);

2746

2016

if(pubkey_fd == -1){

2758

2028

}

2759

2029

}

2760

2030

}

2761

close(pubkey_fd);

2762

}

2763

}

2764

2765

if(dh_params_file != NULL

2766

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

2767

int dhparams_fd = open(dh_params_file, O_RDONLY);

2768

if(dhparams_fd == -1){

2769

perror_plus("open");

2770

} else {

2771

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

2772

if(ret == -1){

2773

perror_plus("fstat");

2774

} else {

2775

if(S_ISREG(st.st_mode)

2776

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

2777

ret = fchown(dhparams_fd, uid, gid);

2778

if(ret == -1){

2779

perror_plus("fchown");

2780

}

2781

}

2782

}

2783

close(dhparams_fd);

2784

}

2785

}

2786

2031

TEMP_FAILURE_RETRY(close(pubkey_fd));

2032

}

2033

}

2034

2787

2035

/* Lower privileges */

2788

ret = lower_privileges();

2789

if(ret != 0){

2790

errno = ret;

2791

perror_plus("Failed to lower privileges");

2792

}

2036

lower_privileges();

2793

2037

}

2794

2038

}

2795

2039

2819

2063

goto end;

2820

2064

}

2821

2065

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

2822

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

2823

}

2824

run_network_hooks("start", interfaces_hooks != NULL ?

2825

interfaces_hooks : "", delay);

2066

interfaces_hooks_size = mc.interfaces_size;

2067

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2068

(int)',');

2069

}

2070

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

2071

interfaces_hooks : "", delay)){

2072

goto end;

2073

}

2826

2074

}

2827

2075

2828

2076

if(not debug){

2906

2154

2907

2155

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

2908

2156

if(mc.interfaces == NULL){

2909

struct dirent **direntries = NULL;

2157

struct dirent **direntries;

2910

2158

/* Look for any good interfaces */

2911

2159

ret = scandir(sys_class_net, &direntries, good_interface,

2912

2160

alphasort);

2916

2164

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

2917

2165

direntries[i]->d_name);

2918

2166

if(ret_errno != 0){

2919

errno = ret_errno;

2920

2167

perror_plus("argz_add");

2921

free(direntries[i]);

2922

2168

continue;

2923

2169

}

2924

2170

if(debug){

2925

2171

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

2926

2172

direntries[i]->d_name);

2927

2173

}

2928

free(direntries[i]);

2929

2174

}

2930

2175

free(direntries);

2931

2176

} else {

2932

if(ret == 0){

2933

free(direntries);

2934

}

2177

free(direntries);

2935

2178

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

2936

2179

exitcode = EXIT_FAILURE;

2937

2180

goto end;

2938

2181

}

2939

2182

}

2940

2183

2941

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

2184

/* Bring up interfaces which are down */

2942

2185

{

2943

2186

char *interface = NULL;

2944

2187

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

2960

2203

break;

2961

2204

}

2962

2205

bool interface_was_up = interface_is_up(interface);

2963

errno = bring_up_interface(interface, delay);

2206

ret = bring_up_interface(interface, delay);

2964

2207

if(not interface_was_up){

2965

if(errno != 0){

2966

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

2967

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

2208

if(ret != 0){

2209

errno = ret;

2210

perror_plus("Failed to bring up interface");

2968

2211

} else {

2969

errno = argz_add(&interfaces_to_take_down,

2970

&interfaces_to_take_down_size,

2971

interface);

2972

if(errno != 0){

2973

perror_plus("argz_add");

2974

}

2212

ret_errno = argz_add(&interfaces_to_take_down,

2213

&interfaces_to_take_down_size,

2214

interface);

2975

2215

}

2976

2216

}

2977

2217

}

2993

2233

goto end;

2994

2234

}

2995

2235

2996

#if GNUTLS_VERSION_NUMBER >= 0x030606

2997

ret = init_gnutls_global(tls_pubkey, tls_privkey, dh_params_file, &mc);

2998

#elif GNUTLS_VERSION_NUMBER < 0x030600

2999

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

3000

#else

3001

#error "Needs GnuTLS 3.6.6 or later, or before 3.6.0"

3002

#endif

2236

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

3003

2237

if(ret == -1){

3004

2238

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

3005

2239

exitcode = EX_UNAVAILABLE;

3012

2246

goto end;

3013

2247

}

3014

2248

3015

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

3016

tempdir = mkdtemp(run_tempdir);

3017

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

3018

if(debug){

3019

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

3020

run_tempdir, old_tempdir);

3021

}

3022

tempdir = mkdtemp(old_tempdir);

3023

}

3024

if(tempdir == NULL){

2249

if(mkdtemp(tempdir) == NULL){

3025

2250

perror_plus("mkdtemp");

3026

2251

goto end;

3027

2252

}

2253

tempdir_created = true;

3028

2254

3029

2255

if(quit_now){

3030

2256

goto end;

3102

2328

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

3103

2329

(int)retry_interval);

3104

2330

}

3105

sleep((unsigned int)retry_interval);

2331

sleep((int)retry_interval);

3106

2332

}

3107

2333

3108

if(not quit_now){

2334

if (not quit_now){

3109

2335

exitcode = EXIT_SUCCESS;

3110

2336

}

3111

2337

3127

2353

3128

2354

/* Allocate a new server */

3129

2355

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

3130

&config, NULL, NULL, &ret);

2356

&config, NULL, NULL, &ret_errno);

3131

2357

3132

2358

/* Free the Avahi configuration data */

3133

2359

avahi_server_config_free(&config);

3136

2362

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

3137

2363

if(mc.server == NULL){

3138

2364

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

3139

avahi_strerror(ret));

2365

avahi_strerror(ret_errno));

3140

2366

exitcode = EX_UNAVAILABLE;

3141

2367

goto end;

3142

2368

}

3166

2392

if(debug){

3167

2393

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

3168

2394

}

3169

2395

3170

2396

ret = avahi_loop_with_timeout(simple_poll,

3171

2397

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

3172

2398

if(debug){

3177

2403

end:

3178

2404

3179

2405

if(debug){

3180

if(signal_received){

3181

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

3182

argv[0], signal_received,

3183

strsignal(signal_received));

3184

} else {

3185

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

3186

}

2406

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

3187

2407

}

3188

2408

3189

2409

/* Cleanup things */

3200

2420

3201

2421

if(gnutls_initialized){

3202

2422

gnutls_certificate_free_credentials(mc.cred);

2423

gnutls_global_deinit();

3203

2424

gnutls_dh_params_deinit(mc.dh_params);

3204

2425

}

3205

2426

3213

2434

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

3214

2435

while(mc.current_server != NULL){

3215

2436

server *next = mc.current_server->next;

3216

#ifdef __GNUC__

3217

#pragma GCC diagnostic push

3218

#pragma GCC diagnostic ignored "-Wcast-qual"

3219

#endif

3220

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

3221

#ifdef __GNUC__

3222

#pragma GCC diagnostic pop

3223

#endif

3224

2437

free(mc.current_server);

3225

2438

mc.current_server = next;

3226

2439

}

3227

2440

}

3228

2441

3229

/* Re-raise privileges */

2442

/* Re-raise priviliges */

3230

2443

{

3231

ret = raise_privileges();

3232

if(ret != 0){

3233

errno = ret;

3234

perror_plus("Failed to raise privileges");

3235

} else {

3236

3237

/* Run network hooks */

3238

run_network_hooks("stop", interfaces_hooks != NULL ?

3239

interfaces_hooks : "", delay);

3240

3241

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

3242

{

3243

char *interface = NULL;

3244

while((interface = argz_next(interfaces_to_take_down,

3245

interfaces_to_take_down_size,

3246

interface))){

3247

ret = take_down_interface(interface);

3248

if(ret != 0){

3249

errno = ret;

3250

perror_plus("Failed to take down interface");

3251

}

3252

}

3253

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

3254

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

3255

" down\n");

3256

}

3257

}

3258

}

3259

3260

ret = lower_privileges_permanently();

3261

if(ret != 0){

3262

errno = ret;

3263

perror_plus("Failed to lower privileges permanently");

3264

}

2444

raise_privileges();

2445

2446

/* Run network hooks */

2447

run_network_hooks("stop", interfaces_hooks != NULL ?

2448

interfaces_hooks : "", delay);

2449

2450

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

2451

{

2452

char *interface = NULL;

2453

while((interface=argz_next(interfaces_to_take_down,

2454

interfaces_to_take_down_size,

2455

interface))){

2456

ret_errno = take_down_interface(interface);

2457

if(ret_errno != 0){

2458

errno = ret_errno;

2459

perror_plus("Failed to take down interface");

2460

}

2461

}

2462

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

2463

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

2464

" down\n");

2465

}

2466

}

2467

2468

lower_privileges_permanently();

3265

2469

}

3266

2470

3267

2471

free(interfaces_to_take_down);

3268

2472

free(interfaces_hooks);

3269

2473

3270

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

3271

uintmax_t level){

2474

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

2475

if(tempdir_created){

3272

2476

struct dirent **direntries = NULL;

3273

int dret;

3274

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

3275

O_RDONLY

3276

| O_NOFOLLOW

3277

| O_DIRECTORY

3278

| O_PATH));

3279

if(dir_fd == -1){

3280

perror_plus("open");

3281

return;

3282

}

3283

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

3284

notdotentries, alphasort);

3285

if(numentries >= 0){

2477

struct dirent *direntry = NULL;

2478

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

2479

alphasort);

2480

if (numentries > 0){

3286

2481

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

3287

if(debug){

3288

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

3289

dirname, direntries[i]->d_name);

3290

}

3291

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

3292

if(dret == -1){

3293

if(errno == EISDIR){

3294

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

3295

AT_REMOVEDIR);

3296

}

3297

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

3298

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

3299

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

3300

/* Recurse only in this special case */

3301

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

3302

dret = 0;

3303

}

3304

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

3305

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

3306

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

3307

}

3308

}

3309

free(direntries[i]);

3310

}

3311

3312

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

3313

free(direntries);

3314

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3315

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

3316

perror_plus("rmdir");

3317

}

3318

} else {

3319

perror_plus("scandirat");

3320

}

3321

close(dir_fd);

3322

}

3323

3324

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

3325

if(tempdir != NULL){

3326

clean_dir_at(-1, tempdir, 0);

2482

direntry = direntries[i];

2483

char *fullname = NULL;

2484

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

2485

direntry->d_name);

2486

if(ret < 0){

2487

perror_plus("asprintf");

2488

continue;

2489

}

2490

ret = remove(fullname);

2491

if(ret == -1){

2492

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

2493

strerror(errno));

2494

}

2495

free(fullname);

2496

}

2497

}

2498

2499

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

2500

free(direntries);

2501

if (numentries == -1){

2502

perror_plus("scandir");

2503

}

2504

ret = rmdir(tempdir);

2505

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

2506

perror_plus("rmdir");

2507

}

3327

2508

}

3328

2509

3329

2510

if(quit_now){