/mandos/release : revision 237.7.471

9

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

10

*

11

* Everything else is

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

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

21

23

* WITHOUT ANY WARRANTY; without even the implied warranty of

22

24

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

23

25

* General Public License for more details.

24

26

*

25

27

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

26

* along with this program. If not, see

27

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

28

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

28

29

*

29

30

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

30

31

*/

32

33

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

33

34

#ifndef _LARGEFILE_SOURCE

34

35

#define _LARGEFILE_SOURCE

35

#endif

36

#endif /* not _LARGEFILE_SOURCE */

36

37

#ifndef _FILE_OFFSET_BITS

37

38

#define _FILE_OFFSET_BITS 64

38

#endif

39

#endif /* not _FILE_OFFSET_BITS */

39

40

41

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

41

42

43

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

43

stdout, ferror(), remove() */

44

stdout, ferror() */

44

45

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

45

46

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

46

47

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

47

48

strtof(), abort() */

48

49

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

49

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

50

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

50

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

51

asprintf(), strncpy(), strsignal()

52

*/

51

53

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

52

54

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

53

55

sockaddr_in6, PF_INET6,

55

57

opendir(), DIR */

56

58

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

57

59

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

58

inet_pton(), connect() */

59

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

60

inet_pton(), connect(),

61

getnameinfo() */

62

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

60

63

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

61

64

*/

62

65

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

63

66

strtoimax() */

64

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

67

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

68

EAI_SYSTEM, ENETUNREACH,

69

EHOSTUNREACH, ECONNREFUSED, EPROTO,

70

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

71

ENOTEMPTY,

65

72

program_invocation_short_name */

66

73

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

67

74

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

72

79

*/

73

80

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

74

81

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

75

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

76

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

82

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

83

unlinkat() */

84

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

77

85

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

78

86

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

79

87

argp_state, struct argp,

91

99

argz_delete(), argz_append(),

92

100

argz_stringify(), argz_add(),

93

101

argz_count() */

102

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

103

EAI_SYSTEM, gai_strerror() */

94

104

95

105

#ifdef __linux__

96

106

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

138

148

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

139

149

char *connect_to = NULL;

140

150

const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

141

152

uid_t uid = 65534;

142

153

gid_t gid = 65534;

143

154

165

155

166

/* Used for passing in values through the Avahi callback functions */

156

167

typedef struct {

157

AvahiSimplePoll *simple_poll;

158

168

AvahiServer *server;

159

169

gnutls_certificate_credentials_t cred;

160

170

unsigned int dh_bits;

162

172

const char *priority;

163

173

gpgme_ctx_t ctx;

164

174

server *current_server;

175

char *interfaces;

176

size_t interfaces_size;

165

177

} mandos_context;

166

178

167

/* global context so signal handler can reach it*/

168

mandos_context mc = { .simple_poll = NULL, .server = NULL,

169

.dh_bits = 1024, .priority = "SECURE256"

170

":!CTYPE-X.509:+CTYPE-OPENPGP",

171

.current_server = NULL };

179

/* global so signal handler can reach it*/

180

AvahiSimplePoll *simple_poll;

172

181

173

182

sig_atomic_t quit_now = 0;

174

183

int signal_received = 0;

182

191

perror(print_text);

183

192

}

184

193

185

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

194

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

186

195

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

187

196

va_list ap;

188

197

va_start (ap, format);

189

198

190

199

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

191

200

program_invocation_short_name));

192

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

201

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

193

202

}

194

203

195

204

/*

197

206

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

198

207

* "buffer_length" is how much is already used.

199

208

*/

209

__attribute__((nonnull, warn_unused_result))

200

210

size_t incbuffer(char **buffer, size_t buffer_length,

201

211

size_t buffer_capacity){

202

212

if(buffer_length + BUFFER_SIZE > buffer_capacity){

203

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

204

if(buffer == NULL){

213

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

214

if(new_buf == NULL){

215

int old_errno = errno;

216

free(*buffer);

217

errno = old_errno;

218

*buffer = NULL;

205

219

return 0;

206

220

}

221

*buffer = new_buf;

207

222

buffer_capacity += BUFFER_SIZE;

208

223

}

209

224

return buffer_capacity;

210

225

}

211

226

212

227

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

228

__attribute__((nonnull, warn_unused_result))

213

229

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

214

int af){

230

int af, server **current_server){

215

231

int ret;

216

232

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

217

233

if(new_server == NULL){

224

240

.af = af };

225

241

if(new_server->ip == NULL){

226

242

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);

227

258

return false;

228

259

}

229

260

/* Special case of first server */

230

if (mc.current_server == NULL){

261

if(*current_server == NULL){

231

262

new_server->next = new_server;

232

263

new_server->prev = new_server;

233

mc.current_server = new_server;

234

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

264

*current_server = new_server;

235

265

} else {

236

new_server->next = mc.current_server;

237

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

266

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

267

new_server->next = *current_server;

268

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

238

269

new_server->prev->next = new_server;

239

mc.current_server->prev = new_server;

240

}

241

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

242

if(ret == -1){

243

perror_plus("clock_gettime");

244

return false;

270

(*current_server)->prev = new_server;

245

271

}

246

272

return true;

247

273

}

249

275

/*

250

276

* Initialize GPGME.

251

277

*/

252

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

253

const char *tempdir){

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){

254

283

gpgme_error_t rc;

255

284

gpgme_engine_info_t engine_info;

256

285

257

258

286

/*

259

287

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

260

288

*/

261

bool import_key(const char *filename){

289

bool import_key(const char * const filename){

262

290

int ret;

263

291

int fd;

264

292

gpgme_data_t pgp_data;

276

304

return false;

277

305

}

278

306

279

rc = gpgme_op_import(mc.ctx, pgp_data);

307

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

280

308

if(rc != GPG_ERR_NO_ERROR){

281

309

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

282

310

gpgme_strsource(rc), gpgme_strerror(rc));

283

311

return false;

284

312

}

285

313

286

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

314

ret = close(fd);

287

315

if(ret == -1){

288

316

perror_plus("close");

289

317

}

326

354

}

327

355

328

356

/* Create new GPGME "context" */

329

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

357

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

330

358

if(rc != GPG_ERR_NO_ERROR){

331

359

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

332

360

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

345

373

* Decrypt OpenPGP data.

346

374

* Returns -1 on error

347

375

*/

376

__attribute__((nonnull, warn_unused_result))

348

377

static ssize_t pgp_packet_decrypt(const char *cryptotext,

349

378

size_t crypto_size,

350

char **plaintext){

379

char **plaintext,

380

mandos_context *mc){

351

381

gpgme_data_t dh_crypto, dh_plain;

352

382

gpgme_error_t rc;

353

383

ssize_t ret;

379

409

380

410

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

381

411

data buffer */

382

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

412

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

383

413

if(rc != GPG_ERR_NO_ERROR){

384

414

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

385

415

gpgme_strsource(rc), gpgme_strerror(rc));

386

416

plaintext_length = -1;

387

417

if(debug){

388

418

gpgme_decrypt_result_t result;

389

result = gpgme_op_decrypt_result(mc.ctx);

419

result = gpgme_op_decrypt_result(mc->ctx);

390

420

if(result == NULL){

391

421

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

392

422

} else {

469

499

return plaintext_length;

470

500

}

471

501

472

static const char * safer_gnutls_strerror(int value){

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){

473

511

const char *ret = gnutls_strerror(value);

474

if(ret == NULL)

475

ret = "(unknown)";

476

return ret;

512

return safe_string(ret);

477

513

}

478

514

479

515

/* GnuTLS log function callback */

516

__attribute__((nonnull))

480

517

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

481

518

const char* string){

482

519

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

483

520

}

484

521

522

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

485

523

static int init_gnutls_global(const char *pubkeyfilename,

486

const char *seckeyfilename){

524

const char *seckeyfilename,

525

const char *dhparamsfilename,

526

mandos_context *mc){

487

527

int ret;

528

unsigned int uret;

488

529

489

530

if(debug){

490

531

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

491

532

}

492

533

493

ret = gnutls_global_init();

494

if(ret != GNUTLS_E_SUCCESS){

495

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

496

safer_gnutls_strerror(ret));

497

return -1;

498

}

499

500

534

if(debug){

501

535

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

502

536

* - GnuTLS manual

506

540

}

507

541

508

542

/* OpenPGP credentials */

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

510

544

if(ret != GNUTLS_E_SUCCESS){

511

545

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

512

546

safer_gnutls_strerror(ret));

513

gnutls_global_deinit();

514

547

return -1;

515

548

}

516

549

522

555

}

523

556

524

557

ret = gnutls_certificate_set_openpgp_key_file

525

(mc.cred, pubkeyfilename, seckeyfilename,

558

(mc->cred, pubkeyfilename, seckeyfilename,

526

559

GNUTLS_OPENPGP_FMT_BASE64);

527

560

if(ret != GNUTLS_E_SUCCESS){

528

561

fprintf_plus(stderr,

534

567

}

535

568

536

569

/* GnuTLS server initialization */

537

ret = gnutls_dh_params_init(&mc.dh_params);

570

ret = gnutls_dh_params_init(&mc->dh_params);

538

571

if(ret != GNUTLS_E_SUCCESS){

539

572

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

540

573

" initialization: %s\n",

541

574

safer_gnutls_strerror(ret));

542

575

goto globalfail;

543

576

}

544

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

545

if(ret != GNUTLS_E_SUCCESS){

546

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

547

safer_gnutls_strerror(ret));

548

goto globalfail;

549

}

550

551

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

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);

552

751

553

752

return 0;

554

753

555

754

globalfail:

556

755

557

gnutls_certificate_free_credentials(mc.cred);

558

gnutls_global_deinit();

559

gnutls_dh_params_deinit(mc.dh_params);

756

gnutls_certificate_free_credentials(mc->cred);

757

gnutls_dh_params_deinit(mc->dh_params);

560

758

return -1;

561

759

}

562

760

563

static int init_gnutls_session(gnutls_session_t *session){

761

__attribute__((nonnull, warn_unused_result))

762

static int init_gnutls_session(gnutls_session_t *session,

763

mandos_context *mc){

564

764

int ret;

565

765

/* GnuTLS session creation */

566

766

do {

578

778

{

579

779

const char *err;

580

780

do {

581

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

781

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

582

782

if(quit_now){

583

783

gnutls_deinit(*session);

584

784

return -1;

595

795

596

796

do {

597

797

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

598

mc.cred);

798

mc->cred);

599

799

if(quit_now){

600

800

gnutls_deinit(*session);

601

801

return -1;

611

811

/* ignore client certificate if any. */

612

812

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

813

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

615

616

814

return 0;

617

815

}

618

816

620

818

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

621

819

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

622

820

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

623

1039

/* Called when a Mandos server is found */

1040

__attribute__((nonnull, warn_unused_result))

624

1041

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

625

1042

AvahiIfIndex if_index,

626

int af){

1043

int af, mandos_context *mc){

627

1044

int ret, tcp_sd = -1;

628

1045

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1046

struct sockaddr_storage to;

633

1047

char *buffer = NULL;

634

1048

char *decrypted_buffer = NULL;

635

1049

size_t buffer_length = 0;

638

1052

int retval = -1;

639

1053

gnutls_session_t session;

640

1054

int pf; /* Protocol family */

1055

bool route_added = false;

641

1056

642

1057

errno = 0;

643

1058

659

1074

return -1;

660

1075

}

661

1076

662

ret = init_gnutls_session(&session);

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);

663

1111

if(ret != 0){

664

1112

return -1;

665

1113

}

669

1117

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

670

1118

}

671

1119

672

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

673

1121

if(tcp_sd < 0){

674

1122

int e = errno;

675

1123

perror_plus("socket");

682

1130

goto mandos_end;

683

1131

}

684

1132

685

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

686

1133

if(af == AF_INET6){

687

to.in6.sin6_family = (sa_family_t)af;

688

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

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);

689

1137

} else { /* IPv4 */

690

to.in.sin_family = (sa_family_t)af;

691

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

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);

692

1141

}

693

1142

if(ret < 0 ){

694

1143

int e = errno;

703

1152

goto mandos_end;

704

1153

}

705

1154

if(af == AF_INET6){

706

to.in6.sin6_port = htons(port);

707

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

708

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

709

-Wunreachable-code*/

1155

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

1156

if(IN6_IS_ADDR_LINKLOCAL

1157

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

710

1158

if(if_index == AVAHI_IF_UNSPEC){

711

1159

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

712

1160

" incomplete without a network interface\n");

714

1162

goto mandos_end;

715

1163

}

716

1164

/* Set the network interface number as scope */

717

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

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

718

1166

}

719

1167

} else {

720

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

721

-Wconversion and

722

-Wunreachable-code */

1168

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

723

1169

}

724

1170

725

1171

if(quit_now){

742

1188

}

743

1189

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

744

1190

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

745

const char *pcret;

746

if(af == AF_INET6){

747

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

748

sizeof(addrstr));

749

} else {

750

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

751

sizeof(addrstr));

752

}

753

if(pcret == NULL){

754

perror_plus("inet_ntop");

755

} else {

756

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

757

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

758

}

759

}

760

}

761

762

if(quit_now){

763

errno = EINTR;

764

goto mandos_end;

765

}

766

767

if(af == AF_INET6){

768

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

769

} else {

770

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

771

}

772

if(ret < 0){

773

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

774

int e = errno;

775

perror_plus("connect");

776

errno = e;

777

}

778

goto mandos_end;

779

}

780

781

if(quit_now){

782

errno = EINTR;

783

goto mandos_end;

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;

784

1271

}

785

1272

786

1273

const char *out = mandos_protocol_version;

937

1424

if(buffer_length > 0){

938

1425

ssize_t decrypted_buffer_size;

939

1426

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

940

&decrypted_buffer);

1427

&decrypted_buffer, mc);

941

1428

if(decrypted_buffer_size >= 0){

942

1429

1430

clearerr(stdout);

943

1431

written = 0;

944

1432

while(written < (size_t) decrypted_buffer_size){

945

1433

if(quit_now){

961

1449

}

962

1450

written += (size_t)ret;

963

1451

}

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

}

964

1462

retval = 0;

965

1463

}

966

1464

}

969

1467

970

1468

mandos_end:

971

1469

{

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

}

972

1476

int e = errno;

973

1477

free(decrypted_buffer);

974

1478

free(buffer);

975

1479

if(tcp_sd >= 0){

976

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

1480

ret = close(tcp_sd);

977

1481

}

978

1482

if(ret == -1){

979

1483

if(e == 0){

1004

1508

AVAHI_GCC_UNUSED AvahiStringList *txt,

1005

1509

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1006

1510

flags,

1007

AVAHI_GCC_UNUSED void* userdata){

1511

void *mc){

1008

1512

if(r == NULL){

1009

1513

return;

1010

1514

}

1013

1517

timed out */

1014

1518

1015

1519

if(quit_now){

1520

avahi_s_service_resolver_free(r);

1016

1521

return;

1017

1522

}

1018

1523

1022

1527

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

1023

1528

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

1024

1529

domain,

1025

avahi_strerror(avahi_server_errno(mc.server)));

1530

avahi_strerror(avahi_server_errno

1531

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

1026

1532

break;

1027

1533

1028

1534

case AVAHI_RESOLVER_FOUND:

1036

1542

}

1037

1543

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

1038

1544

interface,

1039

avahi_proto_to_af(proto));

1545

avahi_proto_to_af(proto),

1546

mc);

1040

1547

if(ret == 0){

1041

avahi_simple_poll_quit(mc.simple_poll);

1548

avahi_simple_poll_quit(simple_poll);

1042

1549

} else {

1043

1550

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

1044

avahi_proto_to_af(proto))){

1551

avahi_proto_to_af(proto),

1552

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

1045

1553

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

1046

1554

" list\n", name);

1047

1555

}

1060

1568

const char *domain,

1061

1569

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1062

1570

flags,

1063

AVAHI_GCC_UNUSED void* userdata){

1571

void *mc){

1064

1572

if(b == NULL){

1065

1573

return;

1066

1574

}

1077

1585

case AVAHI_BROWSER_FAILURE:

1078

1586

1079

1587

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1588

avahi_strerror(avahi_server_errno

1589

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

1590

avahi_simple_poll_quit(simple_poll);

1082

1591

return;

1083

1592

1084

1593

case AVAHI_BROWSER_NEW:

1087

1596

the callback function is called the Avahi server will free the

1088

1597

resolver for us. */

1089

1598

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

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)

1093

1603

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

1094

1604

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1605

avahi_strerror(avahi_server_errno

1606

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

1096

1607

break;

1097

1608

1098

1609

case AVAHI_BROWSER_REMOVE:

1117

1628

signal_received = sig;

1118

1629

int old_errno = errno;

1119

1630

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1631

if(simple_poll != NULL){

1632

avahi_simple_poll_quit(simple_poll);

1122

1633

}

1123

1634

errno = old_errno;

1124

1635

}

1125

1636

1637

__attribute__((nonnull, warn_unused_result))

1126

1638

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

1127

1639

int ret;

1128

error_t ret_errno;

1640

int old_errno;

1129

1641

1130

1642

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

1131

1643

if(s < 0){

1132

ret_errno = errno;

1644

old_errno = errno;

1133

1645

perror_plus("socket");

1134

errno = ret_errno;

1646

errno = old_errno;

1135

1647

return false;

1136

1648

}

1137

strcpy(ifr->ifr_name, ifname);

1649

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

1650

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

1138

1651

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1139

1652

if(ret == -1){

1140

1653

if(debug){

1141

ret_errno = errno;

1654

old_errno = errno;

1142

1655

perror_plus("ioctl SIOCGIFFLAGS");

1143

errno = ret_errno;

1656

errno = old_errno;

1144

1657

}

1145

1658

return false;

1146

1659

}

1147

1660

return true;

1148

1661

}

1149

1662

1663

__attribute__((nonnull, warn_unused_result))

1150

1664

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

1151

1665

1152

1666

/* Reject the loopback device */

1194

1708

* corresponds to an acceptable network device.

1195

1709

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

1196

1710

*/

1711

__attribute__((nonnull, warn_unused_result))

1197

1712

int good_interface(const struct dirent *if_entry){

1198

1713

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

1199

1714

return 0;

1217

1732

/*

1218

1733

* This function determines if a network interface is up.

1219

1734

*/

1735

__attribute__((nonnull, warn_unused_result))

1220

1736

bool interface_is_up(const char *interface){

1221

1737

struct ifreq ifr;

1222

1738

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

1233

1749

/*

1234

1750

* This function determines if a network interface is running

1235

1751

*/

1752

__attribute__((nonnull, warn_unused_result))

1236

1753

bool interface_is_running(const char *interface){

1237

1754

struct ifreq ifr;

1238

1755

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

1246

1763

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

1247

1764

}

1248

1765

1766

__attribute__((nonnull, pure, warn_unused_result))

1249

1767

int notdotentries(const struct dirent *direntry){

1250

1768

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

1251

1769

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

1258

1776

}

1259

1777

1260

1778

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

1779

__attribute__((nonnull, warn_unused_result))

1261

1780

int runnable_hook(const struct dirent *direntry){

1262

1781

int ret;

1263

1782

size_t sret;

1271

1790

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

1272

1791

"abcdefghijklmnopqrstuvwxyz"

1273

1792

"0123456789"

1274

"_-");

1793

"_.-");

1275

1794

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

1276

1795

/* Contains non-allowed characters */

1277

1796

if(debug){

1281

1800

return 0;

1282

1801

}

1283

1802

1284

char *fullname = NULL;

1285

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

1286

if(ret < 0){

1287

perror_plus("asprintf");

1288

return 0;

1289

}

1290

1291

ret = stat(fullname, &st);

1803

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

1292

1804

if(ret == -1){

1293

1805

if(debug){

1294

1806

perror_plus("Could not stat hook");

1318

1830

return 1;

1319

1831

}

1320

1832

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1833

__attribute__((nonnull, warn_unused_result))

1834

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1835

mandos_context *mc){

1322

1836

int ret;

1323

1837

struct timespec now;

1324

1838

struct timespec waited_time;

1325

1839

intmax_t block_time;

1326

1840

1327

1841

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1842

if(mc->current_server == NULL){

1843

if(debug){

1330

1844

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

1331

1845

" No timeout!\n");

1332

1846

}

1333

1847

ret = avahi_simple_poll_iterate(s, -1);

1334

1848

} else {

1335

if (debug){

1849

if(debug){

1336

1850

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

1337

1851

" it, or wait\n");

1338

1852

}

1345

1859

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

1346

1860

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

1347

1861

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1862

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

1349

1863

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1864

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

1351

1865

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

1352

1866

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

1353

1867

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

1355

1869

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

1356

1870

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

1357

1871

1358

if (debug){

1872

if(debug){

1359

1873

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

1360

1874

block_time);

1361

1875

}

1362

1876

1363

1877

if(block_time <= 0){

1364

ret = start_mandos_communication(mc.current_server->ip,

1365

mc.current_server->port,

1366

mc.current_server->if_index,

1367

mc.current_server->af);

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);

1368

1882

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1883

avahi_simple_poll_quit(s);

1370

1884

return 0;

1371

1885

}

1372

1886

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1887

&mc->current_server->last_seen);

1374

1888

if(ret == -1){

1375

1889

perror_plus("clock_gettime");

1376

1890

return -1;

1377

1891

}

1378

mc.current_server = mc.current_server->next;

1892

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

1379

1893

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

1380

1894

servers, but don't block */

1381

1895

}

1383

1897

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

1384

1898

}

1385

1899

if(ret != 0){

1386

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

1900

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

1387

1901

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

1388

1902

}

1389

1903

}

1390

1904

}

1391

1905

}

1392

1906

1393

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

1394

error_t raise_privileges(void){

1395

error_t old_errno = errno;

1396

error_t ret_errno = 0;

1397

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

1398

ret_errno = errno;

1399

perror_plus("seteuid");

1400

}

1401

errno = old_errno;

1402

return ret_errno;

1403

}

1404

1405

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

1406

error_t raise_privileges_permanently(void){

1407

error_t old_errno = errno;

1408

error_t ret_errno = raise_privileges();

1409

if(ret_errno != 0){

1410

errno = old_errno;

1411

return ret_errno;

1412

}

1413

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

1414

ret_errno = errno;

1415

perror_plus("seteuid");

1416

}

1417

errno = old_errno;

1418

return ret_errno;

1419

}

1420

1421

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

1422

error_t lower_privileges(void){

1423

error_t old_errno = errno;

1424

error_t ret_errno = 0;

1425

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

1426

ret_errno = errno;

1427

perror_plus("seteuid");

1428

}

1429

errno = old_errno;

1430

return ret_errno;

1431

}

1432

1433

/* Lower privileges permanently */

1434

error_t lower_privileges_permanently(void){

1435

error_t old_errno = errno;

1436

error_t ret_errno = 0;

1437

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

1438

ret_errno = errno;

1439

perror_plus("setuid");

1440

}

1441

errno = old_errno;

1442

return ret_errno;

1443

}

1444

1445

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

1907

__attribute__((nonnull))

1908

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

1446

1909

const float delay){

1447

struct dirent **direntries;

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);

1928

if(numhooks == -1){

1929

perror_plus("scandir");

1930

return;

1931

}

1448

1932

struct dirent *direntry;

1449

1933

int ret;

1450

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

1451

alphasort);

1452

if(numhooks == -1){

1453

if(errno == ENOENT){

1454

if(debug){

1455

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

1456

" found\n", hookdir);

1457

}

1458

} else {

1459

perror_plus("scandir");

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);

1460

1944

}

1461

} else {

1462

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

1463

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

1464

direntry = direntries[i];

1465

char *fullname = NULL;

1466

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

1467

if(ret < 0){

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){

1468

1991

perror_plus("asprintf");

1469

continue;

1470

}

1471

if(debug){

1472

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

1473

direntry->d_name);

1474

}

1475

pid_t hook_pid = fork();

1476

if(hook_pid == 0){

1477

/* Child */

1478

/* Raise privileges */

1479

raise_privileges_permanently();

1480

/* Set group */

1481

errno = 0;

1482

ret = setgid(0);

1483

if(ret == -1){

1484

perror_plus("setgid");

1485

}

1486

/* Reset supplementary groups */

1487

errno = 0;

1488

ret = setgroups(0, NULL);

1489

if(ret == -1){

1490

perror_plus("setgroups");

1491

}

1492

dup2(devnull, STDIN_FILENO);

1493

close(devnull);

1494

dup2(STDERR_FILENO, STDOUT_FILENO);

1495

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

1496

if(ret == -1){

1497

perror_plus("setenv");

1498

_exit(EX_OSERR);

1499

}

1500

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

1501

if(ret == -1){

1502

perror_plus("setenv");

1503

_exit(EX_OSERR);

1504

}

1505

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

1506

if(ret == -1){

1507

perror_plus("setenv");

1508

_exit(EX_OSERR);

1509

}

1510

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

1511

if(ret == -1){

1512

perror_plus("setenv");

1513

_exit(EX_OSERR);

1514

}

1515

char *delaystring;

1516

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

1517

if(ret == -1){

1518

perror_plus("asprintf");

1519

_exit(EX_OSERR);

1520

}

1521

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

1522

if(ret == -1){

1523

free(delaystring);

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1527

1996

free(delaystring);

1528

if(connect_to != NULL){

1529

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

1530

if(ret == -1){

1531

perror_plus("setenv");

1532

_exit(EX_OSERR);

1533

}

1534

}

1535

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

1536

perror_plus("execl");

1537

_exit(EXIT_FAILURE);

1538

}

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;

1539

2065

} else {

1540

int status;

1541

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

1542

perror_plus("waitpid");

1543

free(fullname);

1544

continue;

1545

}

1546

if(WIFEXITED(status)){

1547

if(WEXITSTATUS(status) != 0){

1548

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

1549

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

1550

WEXITSTATUS(status));

1551

free(fullname);

1552

continue;

1553

}

1554

} else if(WIFSIGNALED(status)){

1555

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

1556

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

1557

WTERMSIG(status));

1558

free(fullname);

1559

continue;

1560

} else {

1561

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

1562

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

1563

free(fullname);

1564

continue;

1565

}

1566

}

1567

free(fullname);

1568

if(debug){

1569

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

1570

direntry->d_name);

1571

}

1572

}

1573

close(devnull);

1574

}

1575

return true;

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);

1576

2085

}

1577

2086

1578

error_t bring_up_interface(const char *const interface,

1579

const float delay){

1580

int sd = -1;

1581

error_t old_errno = errno;

1582

error_t ret_errno = 0;

1583

int ret, ret_setflags;

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;

1584

2092

struct ifreq network;

1585

2093

unsigned int if_index = if_nametoindex(interface);

1586

2094

if(if_index == 0){

1595

2103

}

1596

2104

1597

2105

if(not interface_is_up(interface)){

1598

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

2106

int ret_errno = 0;

2107

int ioctl_errno = 0;

2108

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

1599

2109

ret_errno = errno;

1600

2110

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

1601

2111

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

2112

errno = old_errno;

1602

2113

return ret_errno;

1603

2114

}

1604

network.ifr_flags |= IFF_UP;

2115

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

1605

2116

1606

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1607

if(sd < 0){

2117

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

2118

if(sd == -1){

1608

2119

ret_errno = errno;

1609

2120

perror_plus("socket");

1610

2121

errno = old_errno;

1611

2122

return ret_errno;

1612

2123

}

1613

2124

1614

2125

if(quit_now){

1615

close(sd);

2126

ret = close(sd);

2127

if(ret == -1){

2128

perror_plus("close");

2129

}

1616

2130

errno = old_errno;

1617

2131

return EINTR;

1618

2132

}

1622

2136

interface);

1623

2137

}

1624

2138

1625

/* Raise priviliges */

1626

raise_privileges();

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

}

1627

2145

1628

2146

#ifdef __linux__

1629

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1630

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

1631

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

1632

bool restore_loglevel = true;

1633

if(ret_linux == -1){

1634

restore_loglevel = false;

1635

perror_plus("klogctl");

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

}

1636

2158

}

1637

2159

#endif /* __linux__ */

1638

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

1639

ret_errno = errno;

2160

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

2161

ioctl_errno = errno;

1640

2162

#ifdef __linux__

1641

2163

if(restore_loglevel){

1642

2164

ret_linux = klogctl(7, NULL, 0);

1646

2168

}

1647

2169

#endif /* __linux__ */

1648

2170

1649

/* Lower privileges */

1650

lower_privileges();

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

}

1651

2180

1652

2181

/* Close the socket */

1653

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

2182

ret = close(sd);

1654

2183

if(ret == -1){

1655

2184

perror_plus("close");

1656

2185

}

1657

2186

1658

2187

if(ret_setflags == -1){

1659

errno = ret_errno;

2188

errno = ioctl_errno;

1660

2189

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1661

2190

errno = old_errno;

1662

return ret_errno;

2191

return ioctl_errno;

1663

2192

}

1664

2193

} else if(debug){

1665

2194

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

1668

2197

1669

2198

/* Sleep checking until interface is running.

1670

2199

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

1671

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

2200

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

1672

2201

if(interface_is_running(interface)){

1673

2202

break;

1674

2203

}

1683

2212

return 0;

1684

2213

}

1685

2214

1686

error_t take_down_interface(const char *const interface){

1687

int sd = -1;

1688

error_t old_errno = errno;

1689

error_t ret_errno = 0;

1690

int ret, ret_setflags;

2215

__attribute__((nonnull, warn_unused_result))

2216

int take_down_interface(const char *const interface){

2217

int old_errno = errno;

1691

2218

struct ifreq network;

1692

2219

unsigned int if_index = if_nametoindex(interface);

1693

2220

if(if_index == 0){

1696

2223

return ENXIO;

1697

2224

}

1698

2225

if(interface_is_up(interface)){

2226

int ret_errno = 0;

2227

int ioctl_errno = 0;

1699

2228

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

1700

2229

ret_errno = errno;

1701

2230

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

1702

2231

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

2232

errno = old_errno;

1703

2233

return ret_errno;

1704

2234

}

1705

2235

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

1706

2236

1707

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1708

if(sd < 0){

2237

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

2238

if(sd == -1){

1709

2239

ret_errno = errno;

1710

2240

perror_plus("socket");

1711

2241

errno = old_errno;

1717

2247

interface);

1718

2248

}

1719

2249

1720

/* Raise priviliges */

1721

raise_privileges();

1722

1723

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

1724

ret_errno = errno;

1725

1726

/* Lower privileges */

1727

lower_privileges();

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

}

1728

2269

1729

2270

/* Close the socket */

1730

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

2271

int ret = close(sd);

1731

2272

if(ret == -1){

1732

2273

perror_plus("close");

1733

2274

}

1734

2275

1735

2276

if(ret_setflags == -1){

1736

errno = ret_errno;

2277

errno = ioctl_errno;

1737

2278

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1738

2279

errno = old_errno;

1739

return ret_errno;

2280

return ioctl_errno;

1740

2281

}

1741

2282

} else if(debug){

1742

2283

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

1748

2289

}

1749

2290

1750

2291

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 };

1751

2297

AvahiSServiceBrowser *sb = NULL;

1752

2298

error_t ret_errno;

1753

2299

int ret;

1754

2300

intmax_t tmpmax;

1755

2301

char *tmp;

1756

2302

int exitcode = EXIT_SUCCESS;

1757

char *interfaces = NULL;

1758

size_t interfaces_size = 0;

1759

2303

char *interfaces_to_take_down = NULL;

1760

2304

size_t interfaces_to_take_down_size = 0;

1761

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

1762

bool tempdir_created = false;

2305

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

2306

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

2307

char *tempdir = NULL;

1763

2308

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1764

2309

const char *seckey = PATHDIR "/" SECKEY;

1765

2310

const char *pubkey = PATHDIR "/" PUBKEY;

2311

const char *dh_params_file = NULL;

1766

2312

char *interfaces_hooks = NULL;

1767

size_t interfaces_hooks_size = 0;

1768

2313

1769

2314

bool gnutls_initialized = false;

1770

2315

bool gpgme_initialized = false;

1822

2367

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

1823

2368

" Diffie-Hellman key exchange",

1824

2369

.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 },

1825

2375

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

1826

2376

.arg = "STRING",

1827

2377

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

1861

2411

connect_to = arg;

1862

2412

break;

1863

2413

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

1864

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

1865

(int)',');

2414

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

2415

arg, (int)',');

1866

2416

if(ret_errno != 0){

1867

2417

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

1868

2418

}

1882

2432

}

1883

2433

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

1884

2434

break;

2435

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

2436

dh_params_file = arg;

2437

break;

1885

2438

case 130: /* --priority */

1886

2439

mc.priority = arg;

1887

2440

break;

1927

2480

.args_doc = "",

1928

2481

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

1929

2482

" passwords from a Mandos server" };

1930

ret = argp_parse(&argp, argc, argv,

1931

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1932

switch(ret){

2483

ret_errno = argp_parse(&argp, argc, argv,

2484

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2485

switch(ret_errno){

1933

2486

case 0:

1934

2487

break;

1935

2488

case ENOMEM:

1936

2489

default:

1937

errno = ret;

2490

errno = ret_errno;

1938

2491

perror_plus("argp_parse");

1939

2492

exitcode = EX_OSERR;

1940

2493

goto end;

1943

2496

goto end;

1944

2497

}

1945

2498

}

1946

2499

1947

2500

{

1948

2501

/* Work around Debian bug #633582:

1949

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

2502

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

1950

2503

1951

/* Re-raise priviliges */

1952

if(raise_privileges() == 0){

2504

/* Re-raise privileges */

2505

ret = raise_privileges();

2506

if(ret != 0){

2507

errno = ret;

2508

perror_plus("Failed to raise privileges");

2509

} else {

1953

2510

struct stat st;

1954

2511

1955

2512

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

1969

2526

}

1970

2527

}

1971

2528

}

1972

TEMP_FAILURE_RETRY(close(seckey_fd));

2529

close(seckey_fd);

1973

2530

}

1974

2531

}

1975

2532

1976

2533

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

1977

2534

int pubkey_fd = open(pubkey, O_RDONLY);

1978

2535

if(pubkey_fd == -1){

1990

2547

}

1991

2548

}

1992

2549

}

1993

TEMP_FAILURE_RETRY(close(pubkey_fd));

1994

}

1995

}

1996

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

1997

2576

/* Lower privileges */

1998

errno = 0;

1999

ret = seteuid(uid);

2000

if(ret == -1){

2001

perror_plus("seteuid");

2577

ret = lower_privileges();

2578

if(ret != 0){

2579

errno = ret;

2580

perror_plus("Failed to lower privileges");

2002

2581

}

2003

2582

}

2004

2583

}

2005

2584

2006

/* Remove empty interface names */

2585

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

2007

2586

{

2008

2587

char *interface = NULL;

2009

while((interface = argz_next(interfaces, interfaces_size,

2588

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

2010

2589

interface))){

2011

if(if_nametoindex(interface) == 0){

2012

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

2590

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

2591

and if_nametoindex(interface) == 0){

2592

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

2013

2593

fprintf_plus(stderr, "Not using nonexisting interface"

2014

2594

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

2015

2595

}

2016

argz_delete(&interfaces, &interfaces_size, interface);

2596

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

2017

2597

interface = NULL;

2018

2598

}

2019

2599

}

2021

2601

2022

2602

/* Run network hooks */

2023

2603

{

2024

2025

if(interfaces != NULL){

2026

interfaces_hooks = malloc(interfaces_size);

2604

if(mc.interfaces != NULL){

2605

interfaces_hooks = malloc(mc.interfaces_size);

2027

2606

if(interfaces_hooks == NULL){

2028

2607

perror_plus("malloc");

2029

2608

goto end;

2030

2609

}

2031

memcpy(interfaces_hooks, interfaces, interfaces_size);

2032

interfaces_hooks_size = interfaces_size;

2033

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2034

(int)',');

2035

}

2036

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

2037

interfaces_hooks : "", delay)){

2038

goto end;

2039

}

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);

2040

2615

}

2041

2616

2042

2617

if(not debug){

2047

2622

from the signal handler */

2048

2623

/* Initialize the pseudo-RNG for Avahi */

2049

2624

srand((unsigned int) time(NULL));

2050

mc.simple_poll = avahi_simple_poll_new();

2051

if(mc.simple_poll == NULL){

2625

simple_poll = avahi_simple_poll_new();

2626

if(simple_poll == NULL){

2052

2627

fprintf_plus(stderr,

2053

2628

"Avahi: Failed to create simple poll object.\n");

2054

2629

exitcode = EX_UNAVAILABLE;

2119

2694

}

2120

2695

2121

2696

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

2122

if(interfaces == NULL){

2123

struct dirent **direntries;

2697

if(mc.interfaces == NULL){

2698

struct dirent **direntries = NULL;

2124

2699

/* Look for any good interfaces */

2125

2700

ret = scandir(sys_class_net, &direntries, good_interface,

2126

2701

alphasort);

2127

2702

if(ret >= 1){

2128

2703

/* Add all found interfaces to interfaces list */

2129

2704

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

2130

ret_errno = argz_add(&interfaces, &interfaces_size,

2705

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

2131

2706

direntries[i]->d_name);

2132

2707

if(ret_errno != 0){

2708

errno = ret_errno;

2133

2709

perror_plus("argz_add");

2710

free(direntries[i]);

2134

2711

continue;

2135

2712

}

2136

2713

if(debug){

2137

2714

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

2138

2715

direntries[i]->d_name);

2139

2716

}

2717

free(direntries[i]);

2140

2718

}

2141

2719

free(direntries);

2142

2720

} else {

2143

free(direntries);

2721

if(ret == 0){

2722

free(direntries);

2723

}

2144

2724

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

2145

2725

exitcode = EXIT_FAILURE;

2146

2726

goto end;

2147

2727

}

2148

2728

}

2149

2729

2150

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

2151

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

2152

if(debug){

2153

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

2154

interfaces);

2155

}

2156

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2157

}

2158

2159

/* Bring up interfaces which are down */

2160

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

2161

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

2730

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

2731

{

2162

2732

char *interface = NULL;

2163

while((interface = argz_next(interfaces, interfaces_size,

2733

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

2164

2734

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

}

2165

2751

bool interface_was_up = interface_is_up(interface);

2166

ret = bring_up_interface(interface, delay);

2752

errno = bring_up_interface(interface, delay);

2167

2753

if(not interface_was_up){

2168

if(ret != 0){

2169

errno = ret;

2170

perror_plus("Failed to bring up interface");

2754

if(errno != 0){

2755

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

2756

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

2171

2757

} else {

2172

ret_errno = argz_add(&interfaces_to_take_down,

2173

&interfaces_to_take_down_size,

2174

interface);

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

}

2175

2764

}

2176

2765

}

2177

2766

}

2178

free(interfaces);

2179

interfaces = NULL;

2180

interfaces_size = 0;

2181

2767

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

2182

2768

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

2183

2769

}

2184

2770

}

2185

2771

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

2186

2781

if(quit_now){

2187

2782

goto end;

2188

2783

}

2189

2784

2190

ret = init_gnutls_global(pubkey, seckey);

2785

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

2191

2786

if(ret == -1){

2192

2787

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

2193

2788

exitcode = EX_UNAVAILABLE;

2200

2795

goto end;

2201

2796

}

2202

2797

2203

if(mkdtemp(tempdir) == NULL){

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){

2204

2808

perror_plus("mkdtemp");

2205

2809

goto end;

2206

2810

}

2207

tempdir_created = true;

2208

2811

2209

2812

if(quit_now){

2210

2813

goto end;

2211

2814

}

2212

2815

2213

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

2816

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

2214

2817

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

2215

2818

exitcode = EX_UNAVAILABLE;

2216

2819

goto end;

2246

2849

exitcode = EX_USAGE;

2247

2850

goto end;

2248

2851

}

2249

2852

2250

2853

if(quit_now){

2251

2854

goto end;

2252

2855

}

2273

2876

}

2274

2877

2275

2878

while(not quit_now){

2276

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

2879

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

2880

&mc);

2277

2881

if(quit_now or ret == 0){

2278

2882

break;

2279

2883

}

2281

2885

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

2282

2886

(int)retry_interval);

2283

2887

}

2284

sleep((int)retry_interval);

2888

sleep((unsigned int)retry_interval);

2285

2889

}

2286

2890

2287

if (not quit_now){

2891

if(not quit_now){

2288

2892

exitcode = EXIT_SUCCESS;

2289

2893

}

2290

2894

2305

2909

config.publish_domain = 0;

2306

2910

2307

2911

/* Allocate a new server */

2308

mc.server = avahi_server_new(avahi_simple_poll_get

2309

(mc.simple_poll), &config, NULL,

2310

NULL, &ret_errno);

2912

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2913

&config, NULL, NULL, &ret);

2311

2914

2312

2915

/* Free the Avahi configuration data */

2313

2916

avahi_server_config_free(&config);

2316

2919

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

2317

2920

if(mc.server == NULL){

2318

2921

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

2319

avahi_strerror(ret_errno));

2922

avahi_strerror(ret));

2320

2923

exitcode = EX_UNAVAILABLE;

2321

2924

goto end;

2322

2925

}

2328

2931

/* Create the Avahi service browser */

2329

2932

sb = avahi_s_service_browser_new(mc.server, if_index,

2330

2933

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2331

NULL, 0, browse_callback, NULL);

2934

NULL, 0, browse_callback,

2935

(void *)&mc);

2332

2936

if(sb == NULL){

2333

2937

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

2334

2938

avahi_strerror(avahi_server_errno(mc.server)));

2345

2949

if(debug){

2346

2950

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

2347

2951

}

2348

2349

ret = avahi_loop_with_timeout(mc.simple_poll,

2350

(int)(retry_interval * 1000));

2952

2953

ret = avahi_loop_with_timeout(simple_poll,

2954

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

2351

2955

if(debug){

2352

2956

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

2353

2957

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

2356

2960

end:

2357

2961

2358

2962

if(debug){

2359

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

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

}

2360

2970

}

2361

2971

2362

2972

/* Cleanup things */

2973

free(mc.interfaces);

2974

2363

2975

if(sb != NULL)

2364

2976

avahi_s_service_browser_free(sb);

2365

2977

2366

2978

if(mc.server != NULL)

2367

2979

avahi_server_free(mc.server);

2368

2980

2369

if(mc.simple_poll != NULL)

2370

avahi_simple_poll_free(mc.simple_poll);

2981

if(simple_poll != NULL)

2982

avahi_simple_poll_free(simple_poll);

2371

2983

2372

2984

if(gnutls_initialized){

2373

2985

gnutls_certificate_free_credentials(mc.cred);

2374

gnutls_global_deinit();

2375

2986

gnutls_dh_params_deinit(mc.dh_params);

2376

2987

}

2377

2988

2385

2996

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

2386

2997

while(mc.current_server != NULL){

2387

2998

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

2388

3007

free(mc.current_server);

2389

3008

mc.current_server = next;

2390

3009

}

2391

3010

}

2392

3011

2393

/* Re-raise priviliges */

3012

/* Re-raise privileges */

2394

3013

{

2395

raise_privileges();

2396

2397

/* Run network hooks */

2398

run_network_hooks("stop", interfaces_hooks != NULL ?

2399

interfaces_hooks : "", delay);

2400

2401

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

2402

{

2403

char *interface = NULL;

2404

while((interface=argz_next(interfaces_to_take_down,

2405

interfaces_to_take_down_size,

2406

interface))){

2407

ret_errno = take_down_interface(interface);

2408

if(ret_errno != 0){

2409

errno = ret_errno;

2410

perror_plus("Failed to take down interface");

2411

}

2412

}

2413

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

2414

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

2415

" down\n");

2416

}

2417

}

2418

2419

lower_privileges_permanently();

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

}

2420

3048

}

2421

3049

2422

3050

free(interfaces_to_take_down);

2423

3051

free(interfaces_hooks);

2424

3052

3053

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

3054

uintmax_t level){

3055

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){

3068

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

2425

3109

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

2426

if(tempdir_created){

2427

struct dirent **direntries = NULL;

2428

struct dirent *direntry = NULL;

2429

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

2430

alphasort);

2431

if (numentries > 0){

2432

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

2433

direntry = direntries[i];

2434

char *fullname = NULL;

2435

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

2436

direntry->d_name);

2437

if(ret < 0){

2438

perror_plus("asprintf");

2439

continue;

2440

}

2441

ret = remove(fullname);

2442

if(ret == -1){

2443

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

2444

strerror(errno));

2445

}

2446

free(fullname);

2447

}

2448

}

2449

2450

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

2451

free(direntries);

2452

if (numentries == -1){

2453

perror_plus("scandir");

2454

}

2455

ret = rmdir(tempdir);

2456

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

2457

perror_plus("rmdir");

2458

}

3110

if(tempdir != NULL){

3111

clean_dir_at(-1, tempdir, 0);

2459

3112

}

2460

3113

2461

3114

if(quit_now){