/mandos/release : revision 237.7.485

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

10

*

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* Everything else is

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*

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

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

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

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

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*

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

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13

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*

15

* This file is part of Mandos.

16

*

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

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

19

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

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* (at your option) any later version.

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*

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

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* WITHOUT ANY WARRANTY; without even the implied warranty of

22

24

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

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25

* General Public License for more details.

24

26

*

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27

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

26

* along with this program. If not, see

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

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

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29

*

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30

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

30

31

*/

32

33

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

33

34

#ifndef _LARGEFILE_SOURCE

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35

#define _LARGEFILE_SOURCE

35

#endif

36

#endif /* not _LARGEFILE_SOURCE */

36

37

#ifndef _FILE_OFFSET_BITS

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38

#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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40

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

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42

43

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

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stdout, ferror(), remove() */

44

stdout, ferror() */

44

45

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

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

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47

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

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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,

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EAI_SYSTEM, ENETUNREACH,

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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,

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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;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

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

1927

if(devnull == -1){

1928

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

1929

return;

1930

}

1931

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

1932

runnable_hook, alphasort);

1452

1933

if(numhooks == -1){

1453

1934

perror_plus("scandir");

1454

} else {

1455

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

1456

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

1457

direntry = direntries[i];

1458

char *fullname = NULL;

1459

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

1460

if(ret < 0){

1935

close(devnull);

1936

return;

1937

}

1938

struct dirent *direntry;

1939

int ret;

1940

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

1941

direntry = direntries[i];

1942

if(debug){

1943

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

1944

direntry->d_name);

1945

}

1946

pid_t hook_pid = fork();

1947

if(hook_pid == 0){

1948

/* Child */

1949

/* Raise privileges */

1950

errno = raise_privileges_permanently();

1951

if(errno != 0){

1952

perror_plus("Failed to raise privileges");

1953

_exit(EX_NOPERM);

1954

}

1955

/* Set group */

1956

errno = 0;

1957

ret = setgid(0);

1958

if(ret == -1){

1959

perror_plus("setgid");

1960

_exit(EX_NOPERM);

1961

}

1962

/* Reset supplementary groups */

1963

errno = 0;

1964

ret = setgroups(0, NULL);

1965

if(ret == -1){

1966

perror_plus("setgroups");

1967

_exit(EX_NOPERM);

1968

}

1969

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

1970

if(ret == -1){

1971

perror_plus("setenv");

1972

_exit(EX_OSERR);

1973

}

1974

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

1975

if(ret == -1){

1976

perror_plus("setenv");

1977

_exit(EX_OSERR);

1978

}

1979

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

1980

if(ret == -1){

1981

perror_plus("setenv");

1982

_exit(EX_OSERR);

1983

}

1984

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

1985

if(ret == -1){

1986

perror_plus("setenv");

1987

_exit(EX_OSERR);

1988

}

1989

char *delaystring;

1990

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

1991

if(ret == -1){

1461

1992

perror_plus("asprintf");

1462

continue;

1463

}

1464

if(debug){

1465

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

1466

direntry->d_name);

1467

}

1468

pid_t hook_pid = fork();

1469

if(hook_pid == 0){

1470

/* Child */

1471

/* Raise privileges */

1472

raise_privileges_permanently();

1473

/* Set group */

1474

errno = 0;

1475

ret = setgid(0);

1476

if(ret == -1){

1477

perror_plus("setgid");

1478

}

1479

/* Reset supplementary groups */

1480

errno = 0;

1481

ret = setgroups(0, NULL);

1482

if(ret == -1){

1483

perror_plus("setgroups");

1484

}

1485

dup2(devnull, STDIN_FILENO);

1486

close(devnull);

1487

dup2(STDERR_FILENO, STDOUT_FILENO);

1488

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

1489

if(ret == -1){

1490

perror_plus("setenv");

1491

_exit(EX_OSERR);

1492

}

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

char *delaystring;

1509

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

1510

if(ret == -1){

1511

perror_plus("asprintf");

1512

_exit(EX_OSERR);

1513

}

1514

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

1515

if(ret == -1){

1516

free(delaystring);

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1993

_exit(EX_OSERR);

1994

}

1995

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

1996

if(ret == -1){

1520

1997

free(delaystring);

1521

if(connect_to != NULL){

1522

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

1523

if(ret == -1){

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1527

}

1528

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

1529

perror_plus("execl");

1530

_exit(EXIT_FAILURE);

1531

}

1998

perror_plus("setenv");

1999

_exit(EX_OSERR);

2000

}

2001

free(delaystring);

2002

if(connect_to != NULL){

2003

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

2004

if(ret == -1){

2005

perror_plus("setenv");

2006

_exit(EX_OSERR);

2007

}

2008

}

2009

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

2010

direntry->d_name,

2011

O_RDONLY));

2012

if(hook_fd == -1){

2013

perror_plus("openat");

2014

_exit(EXIT_FAILURE);

2015

}

2016

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

2017

perror_plus("close");

2018

_exit(EXIT_FAILURE);

2019

}

2020

ret = dup2(devnull, STDIN_FILENO);

2021

if(ret == -1){

2022

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

2023

_exit(EX_OSERR);

2024

}

2025

ret = close(devnull);

2026

if(ret == -1){

2027

perror_plus("close");

2028

_exit(EX_OSERR);

2029

}

2030

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2031

if(ret == -1){

2032

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

2033

_exit(EX_OSERR);

2034

}

2035

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

2036

environ) == -1){

2037

perror_plus("fexecve");

2038

_exit(EXIT_FAILURE);

2039

}

2040

} else {

2041

if(hook_pid == -1){

2042

perror_plus("fork");

2043

free(direntry);

2044

continue;

2045

}

2046

int status;

2047

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

2048

perror_plus("waitpid");

2049

free(direntry);

2050

continue;

2051

}

2052

if(WIFEXITED(status)){

2053

if(WEXITSTATUS(status) != 0){

2054

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

2055

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

2056

WEXITSTATUS(status));

2057

free(direntry);

2058

continue;

2059

}

2060

} else if(WIFSIGNALED(status)){

2061

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

2062

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

2063

WTERMSIG(status));

2064

free(direntry);

2065

continue;

1532

2066

} else {

1533

int status;

1534

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

1535

perror_plus("waitpid");

1536

free(fullname);

1537

continue;

1538

}

1539

if(WIFEXITED(status)){

1540

if(WEXITSTATUS(status) != 0){

1541

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

1542

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

1543

WEXITSTATUS(status));

1544

free(fullname);

1545

continue;

1546

}

1547

} else if(WIFSIGNALED(status)){

1548

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

1549

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

1550

WTERMSIG(status));

1551

free(fullname);

1552

continue;

1553

} else {

1554

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

1555

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

1556

free(fullname);

1557

continue;

1558

}

1559

}

1560

free(fullname);

1561

if(debug){

1562

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

1563

direntry->d_name);

1564

}

1565

}

1566

close(devnull);

1567

}

1568

return true;

2067

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

2068

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

2069

free(direntry);

2070

continue;

2071

}

2072

}

2073

if(debug){

2074

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

2075

direntry->d_name);

2076

}

2077

free(direntry);

2078

}

2079

free(direntries);

2080

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

2081

perror_plus("close");

2082

} else {

2083

hookdir_fd = -1;

2084

}

2085

close(devnull);

1569

2086

}

1570

2087

1571

error_t bring_up_interface(const char *const interface,

1572

const float delay){

1573

int sd = -1;

1574

error_t old_errno = errno;

1575

error_t ret_errno = 0;

1576

int ret, ret_setflags;

2088

__attribute__((nonnull, warn_unused_result))

2089

int bring_up_interface(const char *const interface,

2090

const float delay){

2091

int old_errno = errno;

2092

int ret;

1577

2093

struct ifreq network;

1578

2094

unsigned int if_index = if_nametoindex(interface);

1579

2095

if(if_index == 0){

1588

2104

}

1589

2105

1590

2106

if(not interface_is_up(interface)){

1591

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

2107

int ret_errno = 0;

2108

int ioctl_errno = 0;

2109

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

1592

2110

ret_errno = errno;

1593

2111

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

1594

2112

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

2113

errno = old_errno;

1595

2114

return ret_errno;

1596

2115

}

1597

network.ifr_flags |= IFF_UP;

2116

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

1598

2117

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

2118

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

2119

if(sd == -1){

1601

2120

ret_errno = errno;

1602

2121

perror_plus("socket");

1603

2122

errno = old_errno;

1604

2123

return ret_errno;

1605

2124

}

1606

2125

1607

2126

if(quit_now){

1608

close(sd);

2127

ret = close(sd);

2128

if(ret == -1){

2129

perror_plus("close");

2130

}

1609

2131

errno = old_errno;

1610

2132

return EINTR;

1611

2133

}

1615

2137

interface);

1616

2138

}

1617

2139

1618

/* Raise priviliges */

1619

raise_privileges();

2140

/* Raise privileges */

2141

ret_errno = raise_privileges();

2142

if(ret_errno != 0){

2143

errno = ret_errno;

2144

perror_plus("Failed to raise privileges");

2145

}

1620

2146

1621

2147

#ifdef __linux__

1622

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1623

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

1624

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

1625

bool restore_loglevel = true;

1626

if(ret_linux == -1){

1627

restore_loglevel = false;

1628

perror_plus("klogctl");

2148

int ret_linux;

2149

bool restore_loglevel = false;

2150

if(ret_errno == 0){

2151

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2152

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

2153

ret_linux = klogctl(8, NULL, 5);

2154

if(ret_linux == -1){

2155

perror_plus("klogctl");

2156

} else {

2157

restore_loglevel = true;

2158

}

1629

2159

}

1630

2160

#endif /* __linux__ */

1631

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

1632

ret_errno = errno;

2161

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

2162

ioctl_errno = errno;

1633

2163

#ifdef __linux__

1634

2164

if(restore_loglevel){

1635

2165

ret_linux = klogctl(7, NULL, 0);

1639

2169

}

1640

2170

#endif /* __linux__ */

1641

2171

1642

/* Lower privileges */

1643

lower_privileges();

2172

/* If raise_privileges() succeeded above */

2173

if(ret_errno == 0){

2174

/* Lower privileges */

2175

ret_errno = lower_privileges();

2176

if(ret_errno != 0){

2177

errno = ret_errno;

2178

perror_plus("Failed to lower privileges");

2179

}

2180

}

1644

2181

1645

2182

/* Close the socket */

1646

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

2183

ret = close(sd);

1647

2184

if(ret == -1){

1648

2185

perror_plus("close");

1649

2186

}

1650

2187

1651

2188

if(ret_setflags == -1){

1652

errno = ret_errno;

2189

errno = ioctl_errno;

1653

2190

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1654

2191

errno = old_errno;

1655

return ret_errno;

2192

return ioctl_errno;

1656

2193

}

1657

2194

} else if(debug){

1658

2195

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

1661

2198

1662

2199

/* Sleep checking until interface is running.

1663

2200

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

1664

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

2201

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

1665

2202

if(interface_is_running(interface)){

1666

2203

break;

1667

2204

}

1676

2213

return 0;

1677

2214

}

1678

2215

1679

error_t take_down_interface(const char *const interface){

1680

int sd = -1;

1681

error_t old_errno = errno;

1682

error_t ret_errno = 0;

1683

int ret, ret_setflags;

2216

__attribute__((nonnull, warn_unused_result))

2217

int take_down_interface(const char *const interface){

2218

int old_errno = errno;

1684

2219

struct ifreq network;

1685

2220

unsigned int if_index = if_nametoindex(interface);

1686

2221

if(if_index == 0){

1689

2224

return ENXIO;

1690

2225

}

1691

2226

if(interface_is_up(interface)){

2227

int ret_errno = 0;

2228

int ioctl_errno = 0;

1692

2229

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

1693

2230

ret_errno = errno;

1694

2231

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

1695

2232

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

2233

errno = old_errno;

1696

2234

return ret_errno;

1697

2235

}

1698

2236

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

1699

2237

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

2238

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

2239

if(sd == -1){

1702

2240

ret_errno = errno;

1703

2241

perror_plus("socket");

1704

2242

errno = old_errno;

1710

2248

interface);

1711

2249

}

1712

2250

1713

/* Raise priviliges */

1714

raise_privileges();

1715

1716

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

1717

ret_errno = errno;

1718

1719

/* Lower privileges */

1720

lower_privileges();

2251

/* Raise privileges */

2252

ret_errno = raise_privileges();

2253

if(ret_errno != 0){

2254

errno = ret_errno;

2255

perror_plus("Failed to raise privileges");

2256

}

2257

2258

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

2259

ioctl_errno = errno;

2260

2261

/* If raise_privileges() succeeded above */

2262

if(ret_errno == 0){

2263

/* Lower privileges */

2264

ret_errno = lower_privileges();

2265

if(ret_errno != 0){

2266

errno = ret_errno;

2267

perror_plus("Failed to lower privileges");

2268

}

2269

}

1721

2270

1722

2271

/* Close the socket */

1723

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

2272

int ret = close(sd);

1724

2273

if(ret == -1){

1725

2274

perror_plus("close");

1726

2275

}

1727

2276

1728

2277

if(ret_setflags == -1){

1729

errno = ret_errno;

2278

errno = ioctl_errno;

1730

2279

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1731

2280

errno = old_errno;

1732

return ret_errno;

2281

return ioctl_errno;

1733

2282

}

1734

2283

} else if(debug){

1735

2284

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

1741

2290

}

1742

2291

1743

2292

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

2293

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

2294

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

2295

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

2296

.current_server = NULL, .interfaces = NULL,

2297

.interfaces_size = 0 };

1744

2298

AvahiSServiceBrowser *sb = NULL;

1745

2299

error_t ret_errno;

1746

2300

int ret;

1747

2301

intmax_t tmpmax;

1748

2302

char *tmp;

1749

2303

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

1752

2304

char *interfaces_to_take_down = NULL;

1753

2305

size_t interfaces_to_take_down_size = 0;

1754

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

1755

bool tempdir_created = false;

2306

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

2307

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

2308

char *tempdir = NULL;

1756

2309

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1757

2310

const char *seckey = PATHDIR "/" SECKEY;

1758

2311

const char *pubkey = PATHDIR "/" PUBKEY;

2312

const char *dh_params_file = NULL;

1759

2313

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

1761

2314

1762

2315

bool gnutls_initialized = false;

1763

2316

bool gpgme_initialized = false;

1815

2368

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

1816

2369

" Diffie-Hellman key exchange",

1817

2370

.group = 2 },

2371

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

2372

.arg = "FILE",

2373

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

2374

" for the Diffie-Hellman key exchange",

2375

.group = 2 },

1818

2376

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

1819

2377

.arg = "STRING",

1820

2378

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

1854

2412

connect_to = arg;

1855

2413

break;

1856

2414

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

1857

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

1858

(int)',');

2415

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

2416

arg, (int)',');

1859

2417

if(ret_errno != 0){

1860

2418

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

1861

2419

}

1875

2433

}

1876

2434

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

1877

2435

break;

2436

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

2437

dh_params_file = arg;

2438

break;

1878

2439

case 130: /* --priority */

1879

2440

mc.priority = arg;

1880

2441

break;

1920

2481

.args_doc = "",

1921

2482

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

1922

2483

" passwords from a Mandos server" };

1923

ret = argp_parse(&argp, argc, argv,

1924

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1925

switch(ret){

2484

ret_errno = argp_parse(&argp, argc, argv,

2485

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2486

switch(ret_errno){

1926

2487

case 0:

1927

2488

break;

1928

2489

case ENOMEM:

1929

2490

default:

1930

errno = ret;

2491

errno = ret_errno;

1931

2492

perror_plus("argp_parse");

1932

2493

exitcode = EX_OSERR;

1933

2494

goto end;

1936

2497

goto end;

1937

2498

}

1938

2499

}

1939

2500

1940

2501

{

1941

2502

/* Work around Debian bug #633582:

1942

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

2503

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

1943

2504

1944

/* Re-raise priviliges */

1945

if(raise_privileges() == 0){

2505

/* Re-raise privileges */

2506

ret = raise_privileges();

2507

if(ret != 0){

2508

errno = ret;

2509

perror_plus("Failed to raise privileges");

2510

} else {

1946

2511

struct stat st;

1947

2512

1948

2513

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

1962

2527

}

1963

2528

}

1964

2529

}

1965

TEMP_FAILURE_RETRY(close(seckey_fd));

2530

close(seckey_fd);

1966

2531

}

1967

2532

}

1968

2533

1969

2534

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

1970

2535

int pubkey_fd = open(pubkey, O_RDONLY);

1971

2536

if(pubkey_fd == -1){

1983

2548

}

1984

2549

}

1985

2550

}

1986

TEMP_FAILURE_RETRY(close(pubkey_fd));

1987

}

1988

}

1989

2551

close(pubkey_fd);

2552

}

2553

}

2554

2555

if(dh_params_file != NULL

2556

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

2557

int dhparams_fd = open(dh_params_file, O_RDONLY);

2558

if(dhparams_fd == -1){

2559

perror_plus("open");

2560

} else {

2561

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

2562

if(ret == -1){

2563

perror_plus("fstat");

2564

} else {

2565

if(S_ISREG(st.st_mode)

2566

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

2567

ret = fchown(dhparams_fd, uid, gid);

2568

if(ret == -1){

2569

perror_plus("fchown");

2570

}

2571

}

2572

}

2573

close(dhparams_fd);

2574

}

2575

}

2576

1990

2577

/* Lower privileges */

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2578

ret = lower_privileges();

2579

if(ret != 0){

2580

errno = ret;

2581

perror_plus("Failed to lower privileges");

1995

2582

}

1996

2583

}

1997

2584

}

1998

2585

1999

/* Remove empty interface names */

2586

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

2000

2587

{

2001

2588

char *interface = NULL;

2002

while((interface = argz_next(interfaces, interfaces_size,

2589

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

2003

2590

interface))){

2004

if(if_nametoindex(interface) == 0){

2005

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

2591

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

2592

and if_nametoindex(interface) == 0){

2593

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

2006

2594

fprintf_plus(stderr, "Not using nonexisting interface"

2007

2595

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

2008

2596

}

2009

argz_delete(&interfaces, &interfaces_size, interface);

2597

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

2010

2598

interface = NULL;

2011

2599

}

2012

2600

}

2014

2602

2015

2603

/* Run network hooks */

2016

2604

{

2017

ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,

2018

interfaces, interfaces_size);

2019

if(ret_errno != 0){

2020

errno = ret_errno;

2021

perror_plus("argz_append");

2022

goto end;

2023

}

2024

argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');

2025

if(not run_network_hooks("start", interfaces_hooks, delay)){

2026

goto end;

2027

}

2605

if(mc.interfaces != NULL){

2606

interfaces_hooks = malloc(mc.interfaces_size);

2607

if(interfaces_hooks == NULL){

2608

perror_plus("malloc");

2609

goto end;

2610

}

2611

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

2612

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

2613

}

2614

run_network_hooks("start", interfaces_hooks != NULL ?

2615

interfaces_hooks : "", delay);

2028

2616

}

2029

2617

2030

2618

if(not debug){

2035

2623

from the signal handler */

2036

2624

/* Initialize the pseudo-RNG for Avahi */

2037

2625

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

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2626

simple_poll = avahi_simple_poll_new();

2627

if(simple_poll == NULL){

2040

2628

fprintf_plus(stderr,

2041

2629

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

2042

2630

exitcode = EX_UNAVAILABLE;

2107

2695

}

2108

2696

2109

2697

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

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2698

if(mc.interfaces == NULL){

2699

struct dirent **direntries = NULL;

2112

2700

/* Look for any good interfaces */

2113

2701

ret = scandir(sys_class_net, &direntries, good_interface,

2114

2702

alphasort);

2115

2703

if(ret >= 1){

2116

2704

/* Add all found interfaces to interfaces list */

2117

2705

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2706

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

2119

2707

direntries[i]->d_name);

2120

2708

if(ret_errno != 0){

2709

errno = ret_errno;

2121

2710

perror_plus("argz_add");

2711

free(direntries[i]);

2122

2712

continue;

2123

2713

}

2124

2714

if(debug){

2125

2715

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

2126

2716

direntries[i]->d_name);

2127

2717

}

2718

free(direntries[i]);

2128

2719

}

2129

2720

free(direntries);

2130

2721

} else {

2131

free(direntries);

2722

if(ret == 0){

2723

free(direntries);

2724

}

2132

2725

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

2133

2726

exitcode = EXIT_FAILURE;

2134

2727

goto end;

2135

2728

}

2136

2729

}

2137

2730

2138

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

2139

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

2140

if(debug){

2141

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

2142

interfaces);

2143

}

2144

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2145

}

2146

2147

/* Bring up interfaces which are down */

2148

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

2149

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

2731

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

2732

{

2150

2733

char *interface = NULL;

2151

while((interface = argz_next(interfaces, interfaces_size,

2734

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

2152

2735

interface))){

2736

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

2737

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

2738

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

2739

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

2740

interface);

2741

interface = NULL;

2742

while((interface = argz_next(mc.interfaces,

2743

mc.interfaces_size, interface))){

2744

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

2745

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

2746

interface);

2747

interface = NULL;

2748

}

2749

}

2750

break;

2751

}

2153

2752

bool interface_was_up = interface_is_up(interface);

2154

ret = bring_up_interface(interface, delay);

2753

errno = bring_up_interface(interface, delay);

2155

2754

if(not interface_was_up){

2156

if(ret != 0){

2157

errno = ret;

2158

perror_plus("Failed to bring up interface");

2755

if(errno != 0){

2756

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

2757

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

2159

2758

} else {

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

interface);

2759

errno = argz_add(&interfaces_to_take_down,

2760

&interfaces_to_take_down_size,

2761

interface);

2762

if(errno != 0){

2763

perror_plus("argz_add");

2764

}

2163

2765

}

2164

2766

}

2165

2767

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2169

2768

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

2170

2769

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

2171

2770

}

2172

2771

}

2173

2772

2773

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

2774

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

2775

if(debug){

2776

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

2777

mc.interfaces);

2778

}

2779

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

2780

}

2781

2174

2782

if(quit_now){

2175

2783

goto end;

2176

2784

}

2177

2785

2178

ret = init_gnutls_global(pubkey, seckey);

2786

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

2179

2787

if(ret == -1){

2180

2788

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

2181

2789

exitcode = EX_UNAVAILABLE;

2188

2796

goto end;

2189

2797

}

2190

2798

2191

if(mkdtemp(tempdir) == NULL){

2799

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

2800

tempdir = mkdtemp(run_tempdir);

2801

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

2802

if(debug){

2803

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

2804

run_tempdir, old_tempdir);

2805

}

2806

tempdir = mkdtemp(old_tempdir);

2807

}

2808

if(tempdir == NULL){

2192

2809

perror_plus("mkdtemp");

2193

2810

goto end;

2194

2811

}

2195

tempdir_created = true;

2196

2812

2197

2813

if(quit_now){

2198

2814

goto end;

2199

2815

}

2200

2816

2201

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

2817

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

2202

2818

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

2203

2819

exitcode = EX_UNAVAILABLE;

2204

2820

goto end;

2234

2850

exitcode = EX_USAGE;

2235

2851

goto end;

2236

2852

}

2237

2853

2238

2854

if(quit_now){

2239

2855

goto end;

2240

2856

}

2261

2877

}

2262

2878

2263

2879

while(not quit_now){

2264

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

2880

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

2881

&mc);

2265

2882

if(quit_now or ret == 0){

2266

2883

break;

2267

2884

}

2269

2886

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

2270

2887

(int)retry_interval);

2271

2888

}

2272

sleep((int)retry_interval);

2889

sleep((unsigned int)retry_interval);

2273

2890

}

2274

2891

2275

if (not quit_now){

2892

if(not quit_now){

2276

2893

exitcode = EXIT_SUCCESS;

2277

2894

}

2278

2895

2293

2910

config.publish_domain = 0;

2294

2911

2295

2912

/* Allocate a new server */

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2913

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2914

&config, NULL, NULL, &ret);

2299

2915

2300

2916

/* Free the Avahi configuration data */

2301

2917

avahi_server_config_free(&config);

2304

2920

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

2305

2921

if(mc.server == NULL){

2306

2922

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

2307

avahi_strerror(ret_errno));

2923

avahi_strerror(ret));

2308

2924

exitcode = EX_UNAVAILABLE;

2309

2925

goto end;

2310

2926

}

2316

2932

/* Create the Avahi service browser */

2317

2933

sb = avahi_s_service_browser_new(mc.server, if_index,

2318

2934

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2319

NULL, 0, browse_callback, NULL);

2935

NULL, 0, browse_callback,

2936

(void *)&mc);

2320

2937

if(sb == NULL){

2321

2938

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

2322

2939

avahi_strerror(avahi_server_errno(mc.server)));

2333

2950

if(debug){

2334

2951

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

2335

2952

}

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2953

2954

ret = avahi_loop_with_timeout(simple_poll,

2955

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

2339

2956

if(debug){

2340

2957

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

2341

2958

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

2344

2961

end:

2345

2962

2346

2963

if(debug){

2347

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

2964

if(signal_received){

2965

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

2966

argv[0], signal_received,

2967

strsignal(signal_received));

2968

} else {

2969

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

2970

}

2348

2971

}

2349

2972

2350

2973

/* Cleanup things */

2974

free(mc.interfaces);

2975

2351

2976

if(sb != NULL)

2352

2977

avahi_s_service_browser_free(sb);

2353

2978

2354

2979

if(mc.server != NULL)

2355

2980

avahi_server_free(mc.server);

2356

2981

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2982

if(simple_poll != NULL)

2983

avahi_simple_poll_free(simple_poll);

2359

2984

2360

2985

if(gnutls_initialized){

2361

2986

gnutls_certificate_free_credentials(mc.cred);

2362

gnutls_global_deinit();

2363

2987

gnutls_dh_params_deinit(mc.dh_params);

2364

2988

}

2365

2989

2373

2997

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

2374

2998

while(mc.current_server != NULL){

2375

2999

server *next = mc.current_server->next;

3000

#ifdef __GNUC__

3001

#pragma GCC diagnostic push

3002

#pragma GCC diagnostic ignored "-Wcast-qual"

3003

#endif

3004

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

3005

#ifdef __GNUC__

3006

#pragma GCC diagnostic pop

3007

#endif

2376

3008

free(mc.current_server);

2377

3009

mc.current_server = next;

2378

3010

}

2379

3011

}

2380

3012

2381

/* Re-raise priviliges */

3013

/* Re-raise privileges */

2382

3014

{

2383

raise_privileges();

2384

2385

/* Run network hooks */

2386

run_network_hooks("stop", interfaces_hooks, delay);

2387

2388

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

2389

{

2390

char *interface = NULL;

2391

while((interface=argz_next(interfaces_to_take_down,

2392

interfaces_to_take_down_size,

2393

interface))){

2394

ret_errno = take_down_interface(interface);

2395

if(ret_errno != 0){

2396

errno = ret_errno;

2397

perror_plus("Failed to take down interface");

2398

}

2399

}

2400

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

2401

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

2402

" down\n");

2403

}

2404

}

2405

2406

lower_privileges_permanently();

3015

ret = raise_privileges();

3016

if(ret != 0){

3017

errno = ret;

3018

perror_plus("Failed to raise privileges");

3019

} else {

3020

3021

/* Run network hooks */

3022

run_network_hooks("stop", interfaces_hooks != NULL ?

3023

interfaces_hooks : "", delay);

3024

3025

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

3026

{

3027

char *interface = NULL;

3028

while((interface = argz_next(interfaces_to_take_down,

3029

interfaces_to_take_down_size,

3030

interface))){

3031

ret = take_down_interface(interface);

3032

if(ret != 0){

3033

errno = ret;

3034

perror_plus("Failed to take down interface");

3035

}

3036

}

3037

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

3038

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

3039

" down\n");

3040

}

3041

}

3042

}

3043

3044

ret = lower_privileges_permanently();

3045

if(ret != 0){

3046

errno = ret;

3047

perror_plus("Failed to lower privileges permanently");

3048

}

2407

3049

}

2408

3050

2409

3051

free(interfaces_to_take_down);

2410

3052

free(interfaces_hooks);

2411

3053

3054

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

3055

uintmax_t level){

3056

struct dirent **direntries = NULL;

3057

int dret;

3058

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

3059

O_RDONLY

3060

| O_NOFOLLOW

3061

| O_DIRECTORY

3062

| O_PATH));

3063

if(dir_fd == -1){

3064

perror_plus("open");

3065

return;

3066

}

3067

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

3068

notdotentries, alphasort);

3069

if(numentries >= 0){

3070

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

3071

if(debug){

3072

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

3073

dirname, direntries[i]->d_name);

3074

}

3075

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

3076

if(dret == -1){

3077

if(errno == EISDIR){

3078

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

3079

AT_REMOVEDIR);

3080

}

3081

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

3082

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

3083

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

3084

/* Recurse only in this special case */

3085

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

3086

dret = 0;

3087

}

3088

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

3089

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

3090

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

3091

}

3092

}

3093

free(direntries[i]);

3094

}

3095

3096

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

3097

free(direntries);

3098

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3099

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

3100

perror_plus("rmdir");

3101

}

3102

} else {

3103

perror_plus("scandirat");

3104

}

3105

close(dir_fd);

3106

}

3107

2412

3108

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

2413

if(tempdir_created){

2414

struct dirent **direntries = NULL;

2415

struct dirent *direntry = NULL;

2416

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

2417

alphasort);

2418

if (numentries > 0){

2419

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

2420

direntry = direntries[i];

2421

char *fullname = NULL;

2422

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

2423

direntry->d_name);

2424

if(ret < 0){

2425

perror_plus("asprintf");

2426

continue;

2427

}

2428

ret = remove(fullname);

2429

if(ret == -1){

2430

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

2431

strerror(errno));

2432

}

2433

free(fullname);

2434

}

2435

}

2436

2437

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

2438

free(direntries);

2439

if (numentries == -1){

2440

perror_plus("scandir");

2441

}

2442

ret = rmdir(tempdir);

2443

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

2444

perror_plus("rmdir");

2445

}

3109

if(tempdir != NULL){

3110

clean_dir_at(-1, tempdir, 0);

2446

3111

}

2447

3112

2448

3113

if(quit_now){