/mandos/trunk : revision 601

9

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

10

*

11

* Everything else is

12

13

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

41

42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

strtof(), abort() */

48

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

49

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

50

asprintf(), strncpy(), strsignal()

51

*/

49

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

50

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

52

51

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

53

52

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

54

53

sockaddr_in6, PF_INET6,

56

55

opendir(), DIR */

57

56

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

58

57

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

59

inet_pton(), connect(),

60

getnameinfo() */

61

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

58

inet_pton(), connect() */

59

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

62

60

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

63

61

*/

64

62

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

65

63

strtoimax() */

66

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

67

EAI_SYSTEM, ENETUNREACH,

68

EHOSTUNREACH, ECONNREFUSED, EPROTO,

69

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

70

ENOTEMPTY,

64

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

71

65

program_invocation_short_name */

72

66

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

73

67

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

78

72

*/

79

73

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

80

74

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

81

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

82

unlinkat() */

83

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

75

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

76

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

84

77

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

85

78

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

86

79

argp_state, struct argp,

98

91

argz_delete(), argz_append(),

99

92

argz_stringify(), argz_add(),

100

93

argz_count() */

101

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

102

EAI_SYSTEM, gai_strerror() */

103

94

104

95

#ifdef __linux__

105

96

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

147

138

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

148

139

char *connect_to = NULL;

149

140

const char *hookdir = HOOKDIR;

150

int hookdir_fd = -1;

151

141

uid_t uid = 65534;

152

142

gid_t gid = 65534;

153

143

171

161

const char *priority;

172

162

gpgme_ctx_t ctx;

173

163

server *current_server;

174

char *interfaces;

175

size_t interfaces_size;

176

164

} mandos_context;

177

165

178

166

/* global so signal handler can reach it*/

179

167

AvahiSimplePoll *simple_poll;

168

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

169

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

170

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

180

171

181

172

sig_atomic_t quit_now = 0;

182

173

int signal_received = 0;

190

181

perror(print_text);

191

182

}

192

183

193

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

184

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

194

185

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

195

186

va_list ap;

196

187

va_start (ap, format);

197

188

198

189

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

199

190

program_invocation_short_name));

200

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

191

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

201

192

}

202

193

203

194

/*

205

196

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

206

197

* "buffer_length" is how much is already used.

207

198

*/

208

__attribute__((nonnull, warn_unused_result))

209

199

size_t incbuffer(char **buffer, size_t buffer_length,

210

200

size_t buffer_capacity){

211

201

if(buffer_length + BUFFER_SIZE > buffer_capacity){

212

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

213

if(new_buf == NULL){

214

int old_errno = errno;

215

free(*buffer);

216

errno = old_errno;

217

*buffer = NULL;

202

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

203

if(buffer == NULL){

218

204

return 0;

219

205

}

220

*buffer = new_buf;

221

206

buffer_capacity += BUFFER_SIZE;

222

207

}

223

208

return buffer_capacity;

224

209

}

225

210

226

211

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

227

__attribute__((nonnull, warn_unused_result))

228

212

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

229

int af, server **current_server){

213

int af){

230

214

int ret;

231

215

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

232

216

if(new_server == NULL){

239

223

.af = af };

240

224

if(new_server->ip == NULL){

241

225

perror_plus("strdup");

242

free(new_server);

243

return false;

244

}

245

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

246

if(ret == -1){

247

perror_plus("clock_gettime");

248

#ifdef __GNUC__

249

#pragma GCC diagnostic push

250

#pragma GCC diagnostic ignored "-Wcast-qual"

251

#endif

252

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

253

#ifdef __GNUC__

254

#pragma GCC diagnostic pop

255

#endif

256

free(new_server);

257

226

return false;

258

227

}

259

228

/* Special case of first server */

260

if(*current_server == NULL){

229

if (mc.current_server == NULL){

261

230

new_server->next = new_server;

262

231

new_server->prev = new_server;

263

*current_server = new_server;

232

mc.current_server = new_server;

233

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

264

234

} else {

265

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

266

new_server->next = *current_server;

267

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

235

new_server->next = mc.current_server;

236

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

268

237

new_server->prev->next = new_server;

269

(*current_server)->prev = new_server;

238

mc.current_server->prev = new_server;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

return false;

270

244

}

271

245

return true;

272

246

}

274

248

/*

275

249

* Initialize GPGME.

276

250

*/

277

__attribute__((nonnull, warn_unused_result))

278

static bool init_gpgme(const char * const seckey,

279

const char * const pubkey,

280

const char * const tempdir,

281

mandos_context *mc){

251

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

252

const char *tempdir){

282

253

gpgme_error_t rc;

283

254

gpgme_engine_info_t engine_info;

284

255

285

256

/*

286

257

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

287

258

*/

288

bool import_key(const char * const filename){

259

bool import_key(const char *filename){

289

260

int ret;

290

261

int fd;

291

262

gpgme_data_t pgp_data;

303

274

return false;

304

275

}

305

276

306

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

277

rc = gpgme_op_import(mc.ctx, pgp_data);

307

278

if(rc != GPG_ERR_NO_ERROR){

308

279

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

309

280

gpgme_strsource(rc), gpgme_strerror(rc));

310

281

return false;

311

282

}

312

283

313

ret = close(fd);

284

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

314

285

if(ret == -1){

315

286

perror_plus("close");

316

287

}

353

324

}

354

325

355

326

/* Create new GPGME "context" */

356

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

327

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

357

328

if(rc != GPG_ERR_NO_ERROR){

358

329

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

359

330

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

372

343

* Decrypt OpenPGP data.

373

344

* Returns -1 on error

374

345

*/

375

__attribute__((nonnull, warn_unused_result))

376

346

static ssize_t pgp_packet_decrypt(const char *cryptotext,

377

347

size_t crypto_size,

378

char **plaintext,

379

mandos_context *mc){

348

char **plaintext){

380

349

gpgme_data_t dh_crypto, dh_plain;

381

350

gpgme_error_t rc;

382

351

ssize_t ret;

408

377

409

378

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

410

379

data buffer */

411

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

380

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

412

381

if(rc != GPG_ERR_NO_ERROR){

413

382

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

414

383

gpgme_strsource(rc), gpgme_strerror(rc));

415

384

plaintext_length = -1;

416

385

if(debug){

417

386

gpgme_decrypt_result_t result;

418

result = gpgme_op_decrypt_result(mc->ctx);

387

result = gpgme_op_decrypt_result(mc.ctx);

419

388

if(result == NULL){

420

389

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

421

390

} else {

498

467

return plaintext_length;

499

468

}

500

469

501

__attribute__((warn_unused_result, const))

502

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

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

508

__attribute__((warn_unused_result))

509

static const char *safer_gnutls_strerror(int value){

470

static const char * safer_gnutls_strerror(int value){

510

471

const char *ret = gnutls_strerror(value);

511

return safe_string(ret);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

512

475

}

513

476

514

477

/* GnuTLS log function callback */

515

__attribute__((nonnull))

516

478

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

517

479

const char* string){

518

480

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

519

481

}

520

482

521

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

522

483

static int init_gnutls_global(const char *pubkeyfilename,

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

mandos_context *mc){

484

const char *seckeyfilename){

526

485

int ret;

527

unsigned int uret;

528

486

529

487

if(debug){

530

488

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

531

489

}

532

490

491

ret = gnutls_global_init();

492

if(ret != GNUTLS_E_SUCCESS){

493

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

494

safer_gnutls_strerror(ret));

495

return -1;

496

}

497

533

498

if(debug){

534

499

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

535

500

* - GnuTLS manual

539

504

}

540

505

541

506

/* OpenPGP credentials */

542

ret = gnutls_certificate_allocate_credentials(&mc->cred);

507

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

508

if(ret != GNUTLS_E_SUCCESS){

544

509

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

545

510

safer_gnutls_strerror(ret));

511

gnutls_global_deinit();

546

512

return -1;

547

513

}

548

514

554

520

}

555

521

556

522

ret = gnutls_certificate_set_openpgp_key_file

557

(mc->cred, pubkeyfilename, seckeyfilename,

523

(mc.cred, pubkeyfilename, seckeyfilename,

558

524

GNUTLS_OPENPGP_FMT_BASE64);

559

525

if(ret != GNUTLS_E_SUCCESS){

560

526

fprintf_plus(stderr,

566

532

}

567

533

568

534

/* GnuTLS server initialization */

569

ret = gnutls_dh_params_init(&mc->dh_params);

535

ret = gnutls_dh_params_init(&mc.dh_params);

570

536

if(ret != GNUTLS_E_SUCCESS){

571

537

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

572

538

" initialization: %s\n",

573

539

safer_gnutls_strerror(ret));

574

540

goto globalfail;

575

541

}

576

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

577

if(dhparamsfilename != NULL){

578

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

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

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

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

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

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

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

625

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

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

free(params.data);

630

} while(false);

631

}

632

if(dhparamsfilename == NULL){

633

if(mc->dh_bits == 0){

634

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

635

/* Try to read the private key file */

636

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

637

do {

638

int secfile = open(seckeyfilename, O_RDONLY);

639

if(secfile == -1){

640

perror_plus("open");

641

break;

642

}

643

size_t buffer_capacity = 0;

644

while(true){

645

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

646

(size_t)buffer.size,

647

(size_t)buffer_capacity);

648

if(buffer_capacity == 0){

649

perror_plus("incbuffer");

650

free(buffer.data);

651

buffer.data = NULL;

652

break;

653

}

654

ssize_t bytes_read = read(secfile,

655

buffer.data + buffer.size,

656

BUFFER_SIZE);

657

/* EOF */

658

if(bytes_read == 0){

659

break;

660

}

661

/* check bytes_read for failure */

662

if(bytes_read < 0){

663

perror_plus("read");

664

free(buffer.data);

665

buffer.data = NULL;

666

break;

667

}

668

buffer.size += (unsigned int)bytes_read;

669

}

670

close(secfile);

671

} while(false);

672

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

673

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

674

if(buffer.data != NULL){

675

{

676

gnutls_openpgp_privkey_t privkey = NULL;

677

ret = gnutls_openpgp_privkey_init(&privkey);

678

if(ret != GNUTLS_E_SUCCESS){

679

fprintf_plus(stderr, "Error initializing OpenPGP key"

680

" structure: %s",

681

safer_gnutls_strerror(ret));

682

free(buffer.data);

683

buffer.data = NULL;

684

} else {

685

ret = gnutls_openpgp_privkey_import

686

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

687

if(ret != GNUTLS_E_SUCCESS){

688

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

689

safer_gnutls_strerror(ret));

690

privkey = NULL;

691

}

692

free(buffer.data);

693

buffer.data = NULL;

694

if(privkey != NULL){

695

/* Use private key to suggest an appropriate

696

sec_param */

697

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

698

gnutls_openpgp_privkey_deinit(privkey);

699

if(debug){

700

fprintf_plus(stderr, "This OpenPGP key implies using"

701

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

702

safe_string(gnutls_sec_param_get_name

703

(sec_param)));

704

}

705

}

706

}

707

}

708

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

709

/* Err on the side of caution */

710

sec_param = GNUTLS_SEC_PARAM_ULTRA;

711

if(debug){

712

fprintf_plus(stderr, "Falling back to security parameter"

713

" \"%s\"\n",

714

safe_string(gnutls_sec_param_get_name

715

(sec_param)));

716

}

717

}

718

}

719

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

720

if(uret != 0){

721

mc->dh_bits = uret;

722

if(debug){

723

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

724

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

725

safe_string(gnutls_sec_param_get_name

726

(sec_param)),

727

mc->dh_bits);

728

}

729

} else {

730

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

731

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

732

safe_string(gnutls_sec_param_get_name

733

(sec_param)),

734

safer_gnutls_strerror(ret));

735

goto globalfail;

736

}

737

} else if(debug){

738

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

739

mc->dh_bits);

740

}

741

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

742

if(ret != GNUTLS_E_SUCCESS){

743

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

744

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

745

safer_gnutls_strerror(ret));

746

goto globalfail;

747

}

748

}

749

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

542

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

543

if(ret != GNUTLS_E_SUCCESS){

544

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

545

safer_gnutls_strerror(ret));

546

goto globalfail;

547

}

548

549

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

750

550

751

551

return 0;

752

552

753

553

globalfail:

754

554

755

gnutls_certificate_free_credentials(mc->cred);

756

gnutls_dh_params_deinit(mc->dh_params);

555

gnutls_certificate_free_credentials(mc.cred);

556

gnutls_global_deinit();

557

gnutls_dh_params_deinit(mc.dh_params);

757

558

return -1;

758

559

}

759

560

760

__attribute__((nonnull, warn_unused_result))

761

static int init_gnutls_session(gnutls_session_t *session,

762

mandos_context *mc){

561

static int init_gnutls_session(gnutls_session_t *session){

763

562

int ret;

764

563

/* GnuTLS session creation */

765

564

do {

777

576

{

778

577

const char *err;

779

578

do {

780

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

579

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

781

580

if(quit_now){

782

581

gnutls_deinit(*session);

783

582

return -1;

794

593

795

594

do {

796

595

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

797

mc->cred);

596

mc.cred);

798

597

if(quit_now){

799

598

gnutls_deinit(*session);

800

599

return -1;

810

609

/* ignore client certificate if any. */

811

610

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

812

611

612

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

613

813

614

return 0;

814

615

}

815

616

817

618

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

818

619

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

819

620

820

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

821

__attribute__((warn_unused_result))

822

int raise_privileges(void){

823

int old_errno = errno;

824

int ret = 0;

825

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

826

ret = errno;

827

}

828

errno = old_errno;

829

return ret;

830

}

831

832

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

833

__attribute__((warn_unused_result))

834

int raise_privileges_permanently(void){

835

int old_errno = errno;

836

int ret = raise_privileges();

837

if(ret != 0){

838

errno = old_errno;

839

return ret;

840

}

841

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

842

ret = errno;

843

}

844

errno = old_errno;

845

return ret;

846

}

847

848

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

849

__attribute__((warn_unused_result))

850

int lower_privileges(void){

851

int old_errno = errno;

852

int ret = 0;

853

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

854

ret = errno;

855

}

856

errno = old_errno;

857

return ret;

858

}

859

860

/* Lower privileges permanently */

861

__attribute__((warn_unused_result))

862

int lower_privileges_permanently(void){

863

int old_errno = errno;

864

int ret = 0;

865

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

866

ret = errno;

867

}

868

errno = old_errno;

869

return ret;

870

}

871

872

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

873

__attribute__((nonnull, warn_unused_result))

874

static bool add_delete_local_route(const bool add,

875

const char *address,

876

AvahiIfIndex if_index){

877

int ret;

878

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

879

char add_arg[] = "add";

880

char delete_arg[] = "delete";

881

char debug_flag[] = "--debug";

882

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

883

if(pluginhelperdir == NULL){

884

if(debug){

885

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

886

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

887

}

888

return false;

889

}

890

891

char interface[IF_NAMESIZE];

892

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

893

perror_plus("if_indextoname");

894

return false;

895

}

896

897

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

898

if(devnull == -1){

899

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

900

return false;

901

}

902

pid_t pid = fork();

903

if(pid == 0){

904

/* Child */

905

/* Raise privileges */

906

errno = raise_privileges_permanently();

907

if(errno != 0){

908

perror_plus("Failed to raise privileges");

909

/* _exit(EX_NOPERM); */

910

} else {

911

/* Set group */

912

errno = 0;

913

ret = setgid(0);

914

if(ret == -1){

915

perror_plus("setgid");

916

_exit(EX_NOPERM);

917

}

918

/* Reset supplementary groups */

919

errno = 0;

920

ret = setgroups(0, NULL);

921

if(ret == -1){

922

perror_plus("setgroups");

923

_exit(EX_NOPERM);

924

}

925

}

926

ret = dup2(devnull, STDIN_FILENO);

927

if(ret == -1){

928

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

929

_exit(EX_OSERR);

930

}

931

ret = close(devnull);

932

if(ret == -1){

933

perror_plus("close");

934

_exit(EX_OSERR);

935

}

936

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

937

if(ret == -1){

938

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

939

_exit(EX_OSERR);

940

}

941

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

942

O_RDONLY

943

| O_DIRECTORY

944

| O_PATH

945

| O_CLOEXEC));

946

if(helperdir_fd == -1){

947

perror_plus("open");

948

_exit(EX_UNAVAILABLE);

949

}

950

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

951

helper, O_RDONLY));

952

if(helper_fd == -1){

953

perror_plus("openat");

954

close(helperdir_fd);

955

_exit(EX_UNAVAILABLE);

956

}

957

close(helperdir_fd);

958

#ifdef __GNUC__

959

#pragma GCC diagnostic push

960

#pragma GCC diagnostic ignored "-Wcast-qual"

961

#endif

962

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

963

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

964

interface, debug ? debug_flag : NULL, NULL },

965

environ) == -1){

966

#ifdef __GNUC__

967

#pragma GCC diagnostic pop

968

#endif

969

perror_plus("fexecve");

970

_exit(EXIT_FAILURE);

971

}

972

}

973

if(pid == -1){

974

perror_plus("fork");

975

return false;

976

}

977

int status;

978

pid_t pret = -1;

979

errno = 0;

980

do {

981

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

982

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

983

int errno_raising = 0;

984

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

985

errno_raising = errno;

986

perror_plus("Failed to raise privileges in order to"

987

" kill helper program");

988

}

989

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

990

perror_plus("kill");

991

}

992

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

993

perror_plus("Failed to lower privileges after killing"

994

" helper program");

995

}

996

return false;

997

}

998

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

999

if(pret == -1){

1000

perror_plus("waitpid");

1001

return false;

1002

}

1003

if(WIFEXITED(status)){

1004

if(WEXITSTATUS(status) != 0){

1005

fprintf_plus(stderr, "Error: iprouteadddel exited"

1006

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

1007

return false;

1008

}

1009

return true;

1010

}

1011

if(WIFSIGNALED(status)){

1012

fprintf_plus(stderr, "Error: iprouteadddel died by"

1013

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

1014

return false;

1015

}

1016

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

1017

return false;

1018

}

1019

1020

__attribute__((nonnull, warn_unused_result))

1021

static bool add_local_route(const char *address,

1022

AvahiIfIndex if_index){

1023

if(debug){

1024

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

1025

}

1026

return add_delete_local_route(true, address, if_index);

1027

}

1028

1029

__attribute__((nonnull, warn_unused_result))

1030

static bool delete_local_route(const char *address,

1031

AvahiIfIndex if_index){

1032

if(debug){

1033

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

1034

}

1035

return add_delete_local_route(false, address, if_index);

1036

}

1037

1038

621

/* Called when a Mandos server is found */

1039

__attribute__((nonnull, warn_unused_result))

1040

622

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

1041

623

AvahiIfIndex if_index,

1042

int af, mandos_context *mc){

624

int af){

1043

625

int ret, tcp_sd = -1;

1044

626

ssize_t sret;

1045

struct sockaddr_storage to;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

1046

631

char *buffer = NULL;

1047

632

char *decrypted_buffer = NULL;

1048

633

size_t buffer_length = 0;

1051

636

int retval = -1;

1052

637

gnutls_session_t session;

1053

638

int pf; /* Protocol family */

1054

bool route_added = false;

1055

639

1056

640

errno = 0;

1057

641

1073

657

return -1;

1074

658

}

1075

659

1076

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

1077

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

1078

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

1079

bool match = false;

1080

{

1081

char *interface = NULL;

1082

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

1083

interface))){

1084

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

1085

match = true;

1086

break;

1087

}

1088

}

1089

}

1090

if(not match){

1091

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

1092

connect to the server */

1093

if(debug){

1094

char interface[IF_NAMESIZE];

1095

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

1096

perror_plus("if_indextoname");

1097

} else {

1098

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

1099

" \"%s\"\n",

1100

if_indextoname((unsigned int)if_index,

1101

interface));

1102

}

1103

}

1104

return -1;

1105

}

1106

}

1107

1108

ret = init_gnutls_session(&session, mc);

660

ret = init_gnutls_session(&session);

1109

661

if(ret != 0){

1110

662

return -1;

1111

663

}

1115

667

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

1116

668

}

1117

669

1118

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

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

1119

671

if(tcp_sd < 0){

1120

672

int e = errno;

1121

673

perror_plus("socket");

1128

680

goto mandos_end;

1129

681

}

1130

682

683

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

1131

684

if(af == AF_INET6){

1132

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

1133

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

1134

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

685

to.in6.sin6_family = (sa_family_t)af;

686

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

1135

687

} else { /* IPv4 */

1136

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

1137

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

1138

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

688

to.in.sin_family = (sa_family_t)af;

689

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

1139

690

}

1140

691

if(ret < 0 ){

1141

692

int e = errno;

1150

701

goto mandos_end;

1151

702

}

1152

703

if(af == AF_INET6){

1153

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

1154

if(IN6_IS_ADDR_LINKLOCAL

1155

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

704

to.in6.sin6_port = htons(port);

705

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

706

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

707

-Wunreachable-code*/

1156

708

if(if_index == AVAHI_IF_UNSPEC){

1157

709

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

1158

710

" incomplete without a network interface\n");

1160

712

goto mandos_end;

1161

713

}

1162

714

/* Set the network interface number as scope */

1163

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

715

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

716

}

1165

717

} else {

1166

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

718

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

719

-Wconversion and

720

-Wunreachable-code */

1167

721

}

1168

722

1169

723

if(quit_now){

1186

740

}

1187

741

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1188

742

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1189

if(af == AF_INET6){

1190

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

1191

sizeof(struct sockaddr_in6),

1192

addrstr, sizeof(addrstr), NULL, 0,

1193

NI_NUMERICHOST);

1194

} else {

1195

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

1196

sizeof(struct sockaddr_in),

1197

addrstr, sizeof(addrstr), NULL, 0,

1198

NI_NUMERICHOST);

1199

}

1200

if(ret == EAI_SYSTEM){

1201

perror_plus("getnameinfo");

1202

} else if(ret != 0) {

1203

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

1204

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

1205

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

1206

}

1207

}

1208

1209

if(quit_now){

1210

errno = EINTR;

1211

goto mandos_end;

1212

}

1213

1214

while(true){

1215

if(af == AF_INET6){

1216

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

1217

sizeof(struct sockaddr_in6));

1218

} else {

1219

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

1220

sizeof(struct sockaddr_in));

1221

}

1222

if(ret < 0){

1223

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

1224

and if_index != AVAHI_IF_UNSPEC

1225

and connect_to == NULL

1226

and not route_added and

1227

((af == AF_INET6 and not

1228

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1229

&to)->sin6_addr)))

1230

or (af == AF_INET and

1231

/* Not a a IPv4LL address */

1232

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

1233

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

1234

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

1235

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

1236

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

1237

connect to a Mandos server announced by Avahi on a server

1238

host with a global address. Work around this by retrying

1239

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

1240

1241

Avahi bug reference:

1242

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

1243

https://bugs.debian.org/587961

1244

*/

1245

if(debug){

1246

fprintf_plus(stderr, "Mandos server unreachable, trying"

1247

" direct route\n");

1248

}

1249

int e = errno;

1250

route_added = add_local_route(ip, if_index);

1251

if(route_added){

1252

continue;

1253

}

1254

errno = e;

1255

}

1256

if(errno != ECONNREFUSED or debug){

1257

int e = errno;

1258

perror_plus("connect");

1259

errno = e;

1260

}

1261

goto mandos_end;

1262

}

1263

1264

if(quit_now){

1265

errno = EINTR;

1266

goto mandos_end;

1267

}

1268

break;

743

const char *pcret;

744

if(af == AF_INET6){

745

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

746

sizeof(addrstr));

747

} else {

748

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

749

sizeof(addrstr));

750

}

751

if(pcret == NULL){

752

perror_plus("inet_ntop");

753

} else {

754

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

755

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

756

}

757

}

758

}

759

760

if(quit_now){

761

errno = EINTR;

762

goto mandos_end;

763

}

764

765

if(af == AF_INET6){

766

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

767

} else {

768

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

769

}

770

if(ret < 0){

771

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

772

int e = errno;

773

perror_plus("connect");

774

errno = e;

775

}

776

goto mandos_end;

777

}

778

779

if(quit_now){

780

errno = EINTR;

781

goto mandos_end;

1269

782

}

1270

783

1271

784

const char *out = mandos_protocol_version;

1422

935

if(buffer_length > 0){

1423

936

ssize_t decrypted_buffer_size;

1424

937

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1425

&decrypted_buffer, mc);

938

&decrypted_buffer);

1426

939

if(decrypted_buffer_size >= 0){

1427

940

1428

clearerr(stdout);

1429

941

written = 0;

1430

942

while(written < (size_t) decrypted_buffer_size){

1431

943

if(quit_now){

1447

959

}

1448

960

written += (size_t)ret;

1449

961

}

1450

ret = fflush(stdout);

1451

if(ret != 0){

1452

int e = errno;

1453

if(debug){

1454

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

1455

strerror(errno));

1456

}

1457

errno = e;

1458

goto mandos_end;

1459

}

1460

962

retval = 0;

1461

963

}

1462

964

}

1465

967

1466

968

mandos_end:

1467

969

{

1468

if(route_added){

1469

if(not delete_local_route(ip, if_index)){

1470

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

1471

" interface %d", ip, if_index);

1472

}

1473

}

1474

970

int e = errno;

1475

971

free(decrypted_buffer);

1476

972

free(buffer);

1477

973

if(tcp_sd >= 0){

1478

ret = close(tcp_sd);

974

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

1479

975

}

1480

976

if(ret == -1){

1481

977

if(e == 0){

1493

989

return retval;

1494

990

}

1495

991

1496

__attribute__((nonnull))

1497

992

static void resolve_callback(AvahiSServiceResolver *r,

1498

993

AvahiIfIndex interface,

1499

994

AvahiProtocol proto,

1507

1002

AVAHI_GCC_UNUSED AvahiStringList *txt,

1508

1003

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1509

1004

flags,

1510

void *mc){

1005

AVAHI_GCC_UNUSED void* userdata){

1511

1006

if(r == NULL){

1512

1007

return;

1513

1008

}

1516

1011

timed out */

1517

1012

1518

1013

if(quit_now){

1519

avahi_s_service_resolver_free(r);

1520

1014

return;

1521

1015

}

1522

1016

1526

1020

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

1527

1021

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

1528

1022

domain,

1529

avahi_strerror(avahi_server_errno

1530

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

1023

avahi_strerror(avahi_server_errno(mc.server)));

1531

1024

break;

1532

1025

1533

1026

case AVAHI_RESOLVER_FOUND:

1541

1034

}

1542

1035

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

1543

1036

interface,

1544

avahi_proto_to_af(proto),

1545

mc);

1037

avahi_proto_to_af(proto));

1546

1038

if(ret == 0){

1547

1039

avahi_simple_poll_quit(simple_poll);

1548

1040

} else {

1549

1041

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

1550

avahi_proto_to_af(proto),

1551

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

1042

avahi_proto_to_af(proto))){

1552

1043

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

1553

1044

" list\n", name);

1554

1045

}

1567

1058

const char *domain,

1568

1059

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1569

1060

flags,

1570

void *mc){

1061

AVAHI_GCC_UNUSED void* userdata){

1571

1062

if(b == NULL){

1572

1063

return;

1573

1064

}

1584

1075

case AVAHI_BROWSER_FAILURE:

1585

1076

1586

1077

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

1587

avahi_strerror(avahi_server_errno

1588

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

1078

avahi_strerror(avahi_server_errno(mc.server)));

1589

1079

avahi_simple_poll_quit(simple_poll);

1590

1080

return;

1591

1081

1595

1085

the callback function is called the Avahi server will free the

1596

1086

resolver for us. */

1597

1087

1598

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

1599

interface, protocol, name, type,

1600

domain, protocol, 0,

1601

resolve_callback, mc) == NULL)

1088

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

1089

name, type, domain, protocol, 0,

1090

resolve_callback, NULL) == NULL)

1602

1091

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

1603

1092

" %s\n", name,

1604

avahi_strerror(avahi_server_errno

1605

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

1093

avahi_strerror(avahi_server_errno(mc.server)));

1606

1094

break;

1607

1095

1608

1096

case AVAHI_BROWSER_REMOVE:

1633

1121

errno = old_errno;

1634

1122

}

1635

1123

1636

__attribute__((nonnull, warn_unused_result))

1637

1124

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

1638

1125

int ret;

1639

int old_errno;

1126

error_t ret_errno;

1640

1127

1641

1128

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

1642

1129

if(s < 0){

1643

old_errno = errno;

1130

ret_errno = errno;

1644

1131

perror_plus("socket");

1645

errno = old_errno;

1132

errno = ret_errno;

1646

1133

return false;

1647

1134

}

1648

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

1649

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

1135

strcpy(ifr->ifr_name, ifname);

1650

1136

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1651

1137

if(ret == -1){

1652

1138

if(debug){

1653

old_errno = errno;

1139

ret_errno = errno;

1654

1140

perror_plus("ioctl SIOCGIFFLAGS");

1655

errno = old_errno;

1141

errno = ret_errno;

1656

1142

}

1657

1143

return false;

1658

1144

}

1659

1145

return true;

1660

1146

}

1661

1147

1662

__attribute__((nonnull, warn_unused_result))

1663

1148

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

1664

1149

1665

1150

/* Reject the loopback device */

1707

1192

* corresponds to an acceptable network device.

1708

1193

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

1709

1194

*/

1710

__attribute__((nonnull, warn_unused_result))

1711

1195

int good_interface(const struct dirent *if_entry){

1712

1196

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

1713

1197

return 0;

1731

1215

/*

1732

1216

* This function determines if a network interface is up.

1733

1217

*/

1734

__attribute__((nonnull, warn_unused_result))

1735

1218

bool interface_is_up(const char *interface){

1736

1219

struct ifreq ifr;

1737

1220

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

1748

1231

/*

1749

1232

* This function determines if a network interface is running

1750

1233

*/

1751

__attribute__((nonnull, warn_unused_result))

1752

1234

bool interface_is_running(const char *interface){

1753

1235

struct ifreq ifr;

1754

1236

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

1762

1244

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

1763

1245

}

1764

1246

1765

__attribute__((nonnull, pure, warn_unused_result))

1766

1247

int notdotentries(const struct dirent *direntry){

1767

1248

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

1768

1249

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

1775

1256

}

1776

1257

1777

1258

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

1778

__attribute__((nonnull, warn_unused_result))

1779

1259

int runnable_hook(const struct dirent *direntry){

1780

1260

int ret;

1781

1261

size_t sret;

1789

1269

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

1790

1270

"abcdefghijklmnopqrstuvwxyz"

1791

1271

"0123456789"

1792

"_.-");

1272

"_-");

1793

1273

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

1794

1274

/* Contains non-allowed characters */

1795

1275

if(debug){

1799

1279

return 0;

1800

1280

}

1801

1281

1802

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

1282

char *fullname = NULL;

1283

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

1284

if(ret < 0){

1285

perror_plus("asprintf");

1286

return 0;

1287

}

1288

1289

ret = stat(fullname, &st);

1803

1290

if(ret == -1){

1804

1291

if(debug){

1805

1292

perror_plus("Could not stat hook");

1829

1316

return 1;

1830

1317

}

1831

1318

1832

__attribute__((nonnull, warn_unused_result))

1833

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1834

mandos_context *mc){

1319

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1835

1320

int ret;

1836

1321

struct timespec now;

1837

1322

struct timespec waited_time;

1838

1323

intmax_t block_time;

1839

1324

1840

1325

while(true){

1841

if(mc->current_server == NULL){

1842

if(debug){

1326

if(mc.current_server == NULL){

1327

if (debug){

1843

1328

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

1844

1329

" No timeout!\n");

1845

1330

}

1846

1331

ret = avahi_simple_poll_iterate(s, -1);

1847

1332

} else {

1848

if(debug){

1333

if (debug){

1849

1334

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

1850

1335

" it, or wait\n");

1851

1336

}

1858

1343

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

1859

1344

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

1860

1345

waited_time.tv_sec = (now.tv_sec

1861

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

1346

- mc.current_server->last_seen.tv_sec);

1862

1347

waited_time.tv_nsec = (now.tv_nsec

1863

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

1348

- mc.current_server->last_seen.tv_nsec);

1864

1349

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

1865

1350

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

1866

1351

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

1868

1353

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

1869

1354

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

1870

1355

1871

if(debug){

1356

if (debug){

1872

1357

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

1873

1358

block_time);

1874

1359

}

1875

1360

1876

1361

if(block_time <= 0){

1877

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

1878

mc->current_server->port,

1879

mc->current_server->if_index,

1880

mc->current_server->af, mc);

1362

ret = start_mandos_communication(mc.current_server->ip,

1363

mc.current_server->port,

1364

mc.current_server->if_index,

1365

mc.current_server->af);

1881

1366

if(ret == 0){

1882

avahi_simple_poll_quit(s);

1367

avahi_simple_poll_quit(simple_poll);

1883

1368

return 0;

1884

1369

}

1885

1370

ret = clock_gettime(CLOCK_MONOTONIC,

1886

&mc->current_server->last_seen);

1371

&mc.current_server->last_seen);

1887

1372

if(ret == -1){

1888

1373

perror_plus("clock_gettime");

1889

1374

return -1;

1890

1375

}

1891

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

1376

mc.current_server = mc.current_server->next;

1892

1377

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

1893

1378

servers, but don't block */

1894

1379

}

1896

1381

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

1897

1382

}

1898

1383

if(ret != 0){

1899

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

1384

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

1900

1385

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

1901

1386

}

1902

1387

}

1903

1388

}

1904

1389

}

1905

1390

1906

__attribute__((nonnull))

1907

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

1391

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

1392

error_t raise_privileges(void){

1393

error_t old_errno = errno;

1394

error_t ret_errno = 0;

1395

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

1396

ret_errno = errno;

1397

perror_plus("seteuid");

1398

}

1399

errno = old_errno;

1400

return ret_errno;

1401

}

1402

1403

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

1404

error_t raise_privileges_permanently(void){

1405

error_t old_errno = errno;

1406

error_t ret_errno = raise_privileges();

1407

if(ret_errno != 0){

1408

errno = old_errno;

1409

return ret_errno;

1410

}

1411

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

1412

ret_errno = errno;

1413

perror_plus("seteuid");

1414

}

1415

errno = old_errno;

1416

return ret_errno;

1417

}

1418

1419

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

1420

error_t lower_privileges(void){

1421

error_t old_errno = errno;

1422

error_t ret_errno = 0;

1423

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

1424

ret_errno = errno;

1425

perror_plus("seteuid");

1426

}

1427

errno = old_errno;

1428

return ret_errno;

1429

}

1430

1431

/* Lower privileges permanently */

1432

error_t lower_privileges_permanently(void){

1433

error_t old_errno = errno;

1434

error_t ret_errno = 0;

1435

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

1436

ret_errno = errno;

1437

perror_plus("setuid");

1438

}

1439

errno = old_errno;

1440

return ret_errno;

1441

}

1442

1443

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

1908

1444

const float delay){

1909

struct dirent **direntries = NULL;

1910

if(hookdir_fd == -1){

1911

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1912

| O_CLOEXEC);

1913

if(hookdir_fd == -1){

1914

if(errno == ENOENT){

1915

if(debug){

1916

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

1917

" found\n", hookdir);

1918

}

1919

} else {

1920

perror_plus("open");

1921

}

1922

return;

1923

}

1924

}

1925

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

1926

runnable_hook, alphasort);

1445

struct dirent **direntries;

1446

struct dirent *direntry;

1447

int ret;

1448

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

1449

alphasort);

1927

1450

if(numhooks == -1){

1928

perror_plus("scandir");

1929

return;

1930

}

1931

struct dirent *direntry;

1932

int ret;

1933

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

1934

if(devnull == -1){

1935

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

1936

return;

1937

}

1938

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

1939

direntry = direntries[i];

1940

if(debug){

1941

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

1942

direntry->d_name);

1451

if(errno == ENOENT){

1452

if(debug){

1453

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

1454

" found\n", hookdir);

1455

}

1456

} else {

1457

perror_plus("scandir");

1943

1458

}

1944

pid_t hook_pid = fork();

1945

if(hook_pid == 0){

1946

/* Child */

1947

/* Raise privileges */

1948

errno = raise_privileges_permanently();

1949

if(errno != 0){

1950

perror_plus("Failed to raise privileges");

1951

_exit(EX_NOPERM);

1952

}

1953

/* Set group */

1954

errno = 0;

1955

ret = setgid(0);

1956

if(ret == -1){

1957

perror_plus("setgid");

1958

_exit(EX_NOPERM);

1959

}

1960

/* Reset supplementary groups */

1961

errno = 0;

1962

ret = setgroups(0, NULL);

1963

if(ret == -1){

1964

perror_plus("setgroups");

1965

_exit(EX_NOPERM);

1966

}

1967

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

1968

if(ret == -1){

1969

perror_plus("setenv");

1970

_exit(EX_OSERR);

1971

}

1972

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

1973

if(ret == -1){

1974

perror_plus("setenv");

1975

_exit(EX_OSERR);

1976

}

1977

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

1978

if(ret == -1){

1979

perror_plus("setenv");

1980

_exit(EX_OSERR);

1981

}

1982

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

1983

if(ret == -1){

1984

perror_plus("setenv");

1985

_exit(EX_OSERR);

1986

}

1987

char *delaystring;

1988

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

1989

if(ret == -1){

1459

} else {

1460

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

1461

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

1462

direntry = direntries[i];

1463

char *fullname = NULL;

1464

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

1465

if(ret < 0){

1990

1466

perror_plus("asprintf");

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1467

continue;

1468

}

1469

if(debug){

1470

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

1471

direntry->d_name);

1472

}

1473

pid_t hook_pid = fork();

1474

if(hook_pid == 0){

1475

/* Child */

1476

/* Raise privileges */

1477

raise_privileges_permanently();

1478

/* Set group */

1479

errno = 0;

1480

ret = setgid(0);

1481

if(ret == -1){

1482

perror_plus("setgid");

1483

}

1484

/* Reset supplementary groups */

1485

errno = 0;

1486

ret = setgroups(0, NULL);

1487

if(ret == -1){

1488

perror_plus("setgroups");

1489

}

1490

dup2(devnull, STDIN_FILENO);

1491

close(devnull);

1492

dup2(STDERR_FILENO, STDOUT_FILENO);

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

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

1509

if(ret == -1){

1510

perror_plus("setenv");

1511

_exit(EX_OSERR);

1512

}

1513

char *delaystring;

1514

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

1515

if(ret == -1){

1516

perror_plus("asprintf");

1517

_exit(EX_OSERR);

1518

}

1519

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

1520

if(ret == -1){

1521

free(delaystring);

1522

perror_plus("setenv");

1523

_exit(EX_OSERR);

1524

}

1995

1525

free(delaystring);

1996

perror_plus("setenv");

1997

_exit(EX_OSERR);

1998

}

1999

free(delaystring);

2000

if(connect_to != NULL){

2001

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

2002

if(ret == -1){

2003

perror_plus("setenv");

2004

_exit(EX_OSERR);

2005

}

2006

}

2007

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

2008

direntry->d_name,

2009

O_RDONLY));

2010

if(hook_fd == -1){

2011

perror_plus("openat");

2012

_exit(EXIT_FAILURE);

2013

}

2014

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

2015

perror_plus("close");

2016

_exit(EXIT_FAILURE);

2017

}

2018

ret = dup2(devnull, STDIN_FILENO);

2019

if(ret == -1){

2020

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

2021

_exit(EX_OSERR);

2022

}

2023

ret = close(devnull);

2024

if(ret == -1){

2025

perror_plus("close");

2026

_exit(EX_OSERR);

2027

}

2028

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2029

if(ret == -1){

2030

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

2031

_exit(EX_OSERR);

2032

}

2033

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

2034

environ) == -1){

2035

perror_plus("fexecve");

2036

_exit(EXIT_FAILURE);

2037

}

2038

} else {

2039

if(hook_pid == -1){

2040

perror_plus("fork");

2041

free(direntry);

2042

continue;

2043

}

2044

int status;

2045

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

2046

perror_plus("waitpid");

2047

free(direntry);

2048

continue;

2049

}

2050

if(WIFEXITED(status)){

2051

if(WEXITSTATUS(status) != 0){

2052

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

2053

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

2054

WEXITSTATUS(status));

2055

free(direntry);

2056

continue;

2057

}

2058

} else if(WIFSIGNALED(status)){

2059

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

2060

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

2061

WTERMSIG(status));

2062

free(direntry);

2063

continue;

1526

if(connect_to != NULL){

1527

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

1528

if(ret == -1){

1529

perror_plus("setenv");

1530

_exit(EX_OSERR);

1531

}

1532

}

1533

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

1534

perror_plus("execl");

1535

_exit(EXIT_FAILURE);

1536

}

2064

1537

} else {

2065

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

2066

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

2067

free(direntry);

2068

continue;

2069

}

2070

}

2071

if(debug){

2072

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

2073

direntry->d_name);

2074

}

2075

free(direntry);

2076

}

2077

free(direntries);

2078

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

2079

perror_plus("close");

2080

} else {

2081

hookdir_fd = -1;

2082

}

2083

close(devnull);

1538

int status;

1539

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

1540

perror_plus("waitpid");

1541

free(fullname);

1542

continue;

1543

}

1544

if(WIFEXITED(status)){

1545

if(WEXITSTATUS(status) != 0){

1546

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

1547

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

1548

WEXITSTATUS(status));

1549

free(fullname);

1550

continue;

1551

}

1552

} else if(WIFSIGNALED(status)){

1553

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

1554

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

1555

WTERMSIG(status));

1556

free(fullname);

1557

continue;

1558

} else {

1559

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

1560

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

1561

free(fullname);

1562

continue;

1563

}

1564

}

1565

free(fullname);

1566

if(debug){

1567

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

1568

direntry->d_name);

1569

}

1570

}

1571

close(devnull);

1572

}

1573

return true;

2084

1574

}

2085

1575

2086

__attribute__((nonnull, warn_unused_result))

2087

int bring_up_interface(const char *const interface,

2088

const float delay){

2089

int old_errno = errno;

2090

int ret;

1576

error_t bring_up_interface(const char *const interface,

1577

const float delay){

1578

int sd = -1;

1579

error_t old_errno = errno;

1580

error_t ret_errno = 0;

1581

int ret, ret_setflags;

2091

1582

struct ifreq network;

2092

1583

unsigned int if_index = if_nametoindex(interface);

2093

1584

if(if_index == 0){

2102

1593

}

2103

1594

2104

1595

if(not interface_is_up(interface)){

2105

int ret_errno = 0;

2106

int ioctl_errno = 0;

2107

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

1596

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

2108

1597

ret_errno = errno;

2109

1598

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

2110

1599

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

2111

errno = old_errno;

2112

1600

return ret_errno;

2113

1601

}

2114

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

1602

network.ifr_flags |= IFF_UP;

2115

1603

2116

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

2117

if(sd == -1){

1604

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1605

if(sd < 0){

2118

1606

ret_errno = errno;

2119

1607

perror_plus("socket");

2120

1608

errno = old_errno;

2121

1609

return ret_errno;

2122

1610

}

2123

1611

2124

1612

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

1613

close(sd);

2129

1614

errno = old_errno;

2130

1615

return EINTR;

2131

1616

}

2135

1620

interface);

2136

1621

}

2137

1622

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

1623

/* Raise priviliges */

1624

raise_privileges();

2144

1625

2145

1626

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

1627

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1628

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

1629

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

1630

bool restore_loglevel = true;

1631

if(ret_linux == -1){

1632

restore_loglevel = false;

1633

perror_plus("klogctl");

2157

1634

}

2158

1635

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

1636

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

1637

ret_errno = errno;

2161

1638

#ifdef __linux__

2162

1639

if(restore_loglevel){

2163

1640

ret_linux = klogctl(7, NULL, 0);

2167

1644

}

2168

1645

#endif /* __linux__ */

2169

1646

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

1647

/* Lower privileges */

1648

lower_privileges();

2179

1649

2180

1650

/* Close the socket */

2181

ret = close(sd);

1651

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

2182

1652

if(ret == -1){

2183

1653

perror_plus("close");

2184

1654

}

2185

1655

2186

1656

if(ret_setflags == -1){

2187

errno = ioctl_errno;

1657

errno = ret_errno;

2188

1658

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

1659

errno = old_errno;

2190

return ioctl_errno;

1660

return ret_errno;

2191

1661

}

2192

1662

} else if(debug){

2193

1663

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

2211

1681

return 0;

2212

1682

}

2213

1683

2214

__attribute__((nonnull, warn_unused_result))

2215

int take_down_interface(const char *const interface){

2216

int old_errno = errno;

1684

error_t take_down_interface(const char *const interface){

1685

int sd = -1;

1686

error_t old_errno = errno;

1687

error_t ret_errno = 0;

1688

int ret, ret_setflags;

2217

1689

struct ifreq network;

2218

1690

unsigned int if_index = if_nametoindex(interface);

2219

1691

if(if_index == 0){

2222

1694

return ENXIO;

2223

1695

}

2224

1696

if(interface_is_up(interface)){

2225

int ret_errno = 0;

2226

int ioctl_errno = 0;

2227

1697

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

2228

1698

ret_errno = errno;

2229

1699

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

2230

1700

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

2231

errno = old_errno;

2232

1701

return ret_errno;

2233

1702

}

2234

1703

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

2235

1704

2236

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

2237

if(sd == -1){

1705

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1706

if(sd < 0){

2238

1707

ret_errno = errno;

2239

1708

perror_plus("socket");

2240

1709

errno = old_errno;

2246

1715

interface);

2247

1716

}

2248

1717

2249

/* Raise privileges */

2250

ret_errno = raise_privileges();

2251

if(ret_errno != 0){

2252

errno = ret_errno;

2253

perror_plus("Failed to raise privileges");

2254

}

2255

2256

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

2257

ioctl_errno = errno;

2258

2259

/* If raise_privileges() succeeded above */

2260

if(ret_errno == 0){

2261

/* Lower privileges */

2262

ret_errno = lower_privileges();

2263

if(ret_errno != 0){

2264

errno = ret_errno;

2265

perror_plus("Failed to lower privileges");

2266

}

2267

}

1718

/* Raise priviliges */

1719

raise_privileges();

1720

1721

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

1722

ret_errno = errno;

1723

1724

/* Lower privileges */

1725

lower_privileges();

2268

1726

2269

1727

/* Close the socket */

2270

int ret = close(sd);

1728

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

2271

1729

if(ret == -1){

2272

1730

perror_plus("close");

2273

1731

}

2274

1732

2275

1733

if(ret_setflags == -1){

2276

errno = ioctl_errno;

1734

errno = ret_errno;

2277

1735

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2278

1736

errno = old_errno;

2279

return ioctl_errno;

1737

return ret_errno;

2280

1738

}

2281

1739

} else if(debug){

2282

1740

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

2288

1746

}

2289

1747

2290

1748

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

2291

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

2292

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

2293

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

2294

.current_server = NULL, .interfaces = NULL,

2295

.interfaces_size = 0 };

2296

1749

AvahiSServiceBrowser *sb = NULL;

2297

1750

error_t ret_errno;

2298

1751

int ret;

2299

1752

intmax_t tmpmax;

2300

1753

char *tmp;

2301

1754

int exitcode = EXIT_SUCCESS;

1755

char *interfaces = NULL;

1756

size_t interfaces_size = 0;

2302

1757

char *interfaces_to_take_down = NULL;

2303

1758

size_t interfaces_to_take_down_size = 0;

2304

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

2305

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

2306

char *tempdir = NULL;

1759

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

1760

bool tempdir_created = false;

2307

1761

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2308

1762

const char *seckey = PATHDIR "/" SECKEY;

2309

1763

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

2311

1764

char *interfaces_hooks = NULL;

1765

size_t interfaces_hooks_size = 0;

2312

1766

2313

1767

bool gnutls_initialized = false;

2314

1768

bool gpgme_initialized = false;

2366

1820

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

2367

1821

" Diffie-Hellman key exchange",

2368

1822

.group = 2 },

2369

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

2370

.arg = "FILE",

2371

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

2372

" for the Diffie-Hellman key exchange",

2373

.group = 2 },

2374

1823

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

2375

1824

.arg = "STRING",

2376

1825

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

2410

1859

connect_to = arg;

2411

1860

break;

2412

1861

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

2413

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

2414

arg, (int)',');

1862

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

1863

(int)',');

2415

1864

if(ret_errno != 0){

2416

1865

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

2417

1866

}

2431

1880

}

2432

1881

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

2433

1882

break;

2434

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

2435

dh_params_file = arg;

2436

break;

2437

1883

case 130: /* --priority */

2438

1884

mc.priority = arg;

2439

1885

break;

2479

1925

.args_doc = "",

2480

1926

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

2481

1927

" passwords from a Mandos server" };

2482

ret_errno = argp_parse(&argp, argc, argv,

2483

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2484

switch(ret_errno){

1928

ret = argp_parse(&argp, argc, argv,

1929

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1930

switch(ret){

2485

1931

case 0:

2486

1932

break;

2487

1933

case ENOMEM:

2488

1934

default:

2489

errno = ret_errno;

1935

errno = ret;

2490

1936

perror_plus("argp_parse");

2491

1937

exitcode = EX_OSERR;

2492

1938

goto end;

2495

1941

goto end;

2496

1942

}

2497

1943

}

2498

1944

2499

1945

{

2500

1946

/* Work around Debian bug #633582:

2501

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

1947

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

2502

1948

2503

/* Re-raise privileges */

2504

ret = raise_privileges();

2505

if(ret != 0){

2506

errno = ret;

2507

perror_plus("Failed to raise privileges");

2508

} else {

1949

/* Re-raise priviliges */

1950

if(raise_privileges() == 0){

2509

1951

struct stat st;

2510

1952

2511

1953

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

2525

1967

}

2526

1968

}

2527

1969

}

2528

close(seckey_fd);

1970

TEMP_FAILURE_RETRY(close(seckey_fd));

2529

1971

}

2530

1972

}

2531

1973

2532

1974

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

2533

1975

int pubkey_fd = open(pubkey, O_RDONLY);

2534

1976

if(pubkey_fd == -1){

2546

1988

}

2547

1989

}

2548

1990

}

2549

close(pubkey_fd);

2550

}

2551

}

2552

2553

if(dh_params_file != NULL

2554

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

2555

int dhparams_fd = open(dh_params_file, O_RDONLY);

2556

if(dhparams_fd == -1){

2557

perror_plus("open");

2558

} else {

2559

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

2560

if(ret == -1){

2561

perror_plus("fstat");

2562

} else {

2563

if(S_ISREG(st.st_mode)

2564

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

2565

ret = fchown(dhparams_fd, uid, gid);

2566

if(ret == -1){

2567

perror_plus("fchown");

2568

}

2569

}

2570

}

2571

close(dhparams_fd);

2572

}

2573

}

2574

1991

TEMP_FAILURE_RETRY(close(pubkey_fd));

1992

}

1993

}

1994

2575

1995

/* Lower privileges */

2576

ret = lower_privileges();

2577

if(ret != 0){

2578

errno = ret;

2579

perror_plus("Failed to lower privileges");

1996

errno = 0;

1997

ret = seteuid(uid);

1998

if(ret == -1){

1999

perror_plus("seteuid");

2580

2000

}

2581

2001

}

2582

2002

}

2583

2003

2584

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

2004

/* Remove empty interface names */

2585

2005

{

2586

2006

char *interface = NULL;

2587

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

2007

while((interface = argz_next(interfaces, interfaces_size,

2588

2008

interface))){

2589

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

2590

and if_nametoindex(interface) == 0){

2591

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

2009

if(if_nametoindex(interface) == 0){

2010

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

2592

2011

fprintf_plus(stderr, "Not using nonexisting interface"

2593

2012

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

2594

2013

}

2595

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

2014

argz_delete(&interfaces, &interfaces_size, interface);

2596

2015

interface = NULL;

2597

2016

}

2598

2017

}

2600

2019

2601

2020

/* Run network hooks */

2602

2021

{

2603

if(mc.interfaces != NULL){

2604

interfaces_hooks = malloc(mc.interfaces_size);

2022

2023

if(interfaces != NULL){

2024

interfaces_hooks = malloc(interfaces_size);

2605

2025

if(interfaces_hooks == NULL){

2606

2026

perror_plus("malloc");

2607

2027

goto end;

2608

2028

}

2609

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

2610

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

2611

}

2612

run_network_hooks("start", interfaces_hooks != NULL ?

2613

interfaces_hooks : "", delay);

2029

memcpy(interfaces_hooks, interfaces, interfaces_size);

2030

interfaces_hooks_size = interfaces_size;

2031

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2032

(int)',');

2033

}

2034

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

2035

interfaces_hooks : "", delay)){

2036

goto end;

2037

}

2614

2038

}

2615

2039

2616

2040

if(not debug){

2693

2117

}

2694

2118

2695

2119

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

2696

if(mc.interfaces == NULL){

2697

struct dirent **direntries = NULL;

2120

if(interfaces == NULL){

2121

struct dirent **direntries;

2698

2122

/* Look for any good interfaces */

2699

2123

ret = scandir(sys_class_net, &direntries, good_interface,

2700

2124

alphasort);

2701

2125

if(ret >= 1){

2702

2126

/* Add all found interfaces to interfaces list */

2703

2127

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

2704

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

2128

ret_errno = argz_add(&interfaces, &interfaces_size,

2705

2129

direntries[i]->d_name);

2706

2130

if(ret_errno != 0){

2707

errno = ret_errno;

2708

2131

perror_plus("argz_add");

2709

free(direntries[i]);

2710

2132

continue;

2711

2133

}

2712

2134

if(debug){

2713

2135

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

2714

2136

direntries[i]->d_name);

2715

2137

}

2716

free(direntries[i]);

2717

2138

}

2718

2139

free(direntries);

2719

2140

} else {

2720

if(ret == 0){

2721

free(direntries);

2722

}

2141

free(direntries);

2723

2142

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

2724

2143

exitcode = EXIT_FAILURE;

2725

2144

goto end;

2726

2145

}

2727

2146

}

2728

2147

2729

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

2730

{

2148

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

2149

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

2150

if(debug){

2151

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

2152

interfaces);

2153

}

2154

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2155

}

2156

2157

/* Bring up interfaces which are down */

2158

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

2159

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

2731

2160

char *interface = NULL;

2732

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

2161

while((interface = argz_next(interfaces, interfaces_size,

2733

2162

interface))){

2734

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

2735

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

2736

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

2737

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

2738

interface);

2739

interface = NULL;

2740

while((interface = argz_next(mc.interfaces,

2741

mc.interfaces_size, interface))){

2742

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

2743

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

2744

interface);

2745

interface = NULL;

2746

}

2747

}

2748

break;

2749

}

2750

2163

bool interface_was_up = interface_is_up(interface);

2751

errno = bring_up_interface(interface, delay);

2164

ret = bring_up_interface(interface, delay);

2752

2165

if(not interface_was_up){

2753

if(errno != 0){

2754

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

2755

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

2166

if(ret != 0){

2167

errno = ret;

2168

perror_plus("Failed to bring up interface");

2756

2169

} else {

2757

errno = argz_add(&interfaces_to_take_down,

2758

&interfaces_to_take_down_size,

2759

interface);

2760

if(errno != 0){

2761

perror_plus("argz_add");

2762

}

2170

ret_errno = argz_add(&interfaces_to_take_down,

2171

&interfaces_to_take_down_size,

2172

interface);

2763

2173

}

2764

2174

}

2765

2175

}

2176

free(interfaces);

2177

interfaces = NULL;

2178

interfaces_size = 0;

2766

2179

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

2767

2180

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

2768

2181

}

2769

2182

}

2770

2183

2771

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

2772

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

2773

if(debug){

2774

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

2775

mc.interfaces);

2776

}

2777

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

2778

}

2779

2780

2184

if(quit_now){

2781

2185

goto end;

2782

2186

}

2783

2187

2784

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

2188

ret = init_gnutls_global(pubkey, seckey);

2785

2189

if(ret == -1){

2786

2190

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

2787

2191

exitcode = EX_UNAVAILABLE;

2794

2198

goto end;

2795

2199

}

2796

2200

2797

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

2798

tempdir = mkdtemp(run_tempdir);

2799

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

2800

if(debug){

2801

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

2802

run_tempdir, old_tempdir);

2803

}

2804

tempdir = mkdtemp(old_tempdir);

2805

}

2806

if(tempdir == NULL){

2201

if(mkdtemp(tempdir) == NULL){

2807

2202

perror_plus("mkdtemp");

2808

2203

goto end;

2809

2204

}

2205

tempdir_created = true;

2810

2206

2811

2207

if(quit_now){

2812

2208

goto end;

2813

2209

}

2814

2210

2815

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

2211

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

2816

2212

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

2817

2213

exitcode = EX_UNAVAILABLE;

2818

2214

goto end;

2848

2244

exitcode = EX_USAGE;

2849

2245

goto end;

2850

2246

}

2851

2247

2852

2248

if(quit_now){

2853

2249

goto end;

2854

2250

}

2875

2271

}

2876

2272

2877

2273

while(not quit_now){

2878

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

2879

&mc);

2274

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

2880

2275

if(quit_now or ret == 0){

2881

2276

break;

2882

2277

}

2884

2279

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

2885

2280

(int)retry_interval);

2886

2281

}

2887

sleep((unsigned int)retry_interval);

2282

sleep((int)retry_interval);

2888

2283

}

2889

2284

2890

if(not quit_now){

2285

if (not quit_now){

2891

2286

exitcode = EXIT_SUCCESS;

2892

2287

}

2893

2288

2909

2304

2910

2305

/* Allocate a new server */

2911

2306

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2912

&config, NULL, NULL, &ret);

2307

&config, NULL, NULL, &ret_errno);

2913

2308

2914

2309

/* Free the Avahi configuration data */

2915

2310

avahi_server_config_free(&config);

2918

2313

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

2919

2314

if(mc.server == NULL){

2920

2315

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

2921

avahi_strerror(ret));

2316

avahi_strerror(ret_errno));

2922

2317

exitcode = EX_UNAVAILABLE;

2923

2318

goto end;

2924

2319

}

2930

2325

/* Create the Avahi service browser */

2931

2326

sb = avahi_s_service_browser_new(mc.server, if_index,

2932

2327

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2933

NULL, 0, browse_callback,

2934

(void *)&mc);

2328

NULL, 0, browse_callback, NULL);

2935

2329

if(sb == NULL){

2936

2330

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

2937

2331

avahi_strerror(avahi_server_errno(mc.server)));

2948

2342

if(debug){

2949

2343

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

2950

2344

}

2951

2345

2952

2346

ret = avahi_loop_with_timeout(simple_poll,

2953

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

2347

(int)(retry_interval * 1000));

2954

2348

if(debug){

2955

2349

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

2956

2350

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

2959

2353

end:

2960

2354

2961

2355

if(debug){

2962

if(signal_received){

2963

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

2964

argv[0], signal_received,

2965

strsignal(signal_received));

2966

} else {

2967

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

2968

}

2356

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

2969

2357

}

2970

2358

2971

2359

/* Cleanup things */

2972

free(mc.interfaces);

2973

2974

2360

if(sb != NULL)

2975

2361

avahi_s_service_browser_free(sb);

2976

2362

2982

2368

2983

2369

if(gnutls_initialized){

2984

2370

gnutls_certificate_free_credentials(mc.cred);

2371

gnutls_global_deinit();

2985

2372

gnutls_dh_params_deinit(mc.dh_params);

2986

2373

}

2987

2374

2995

2382

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

2996

2383

while(mc.current_server != NULL){

2997

2384

server *next = mc.current_server->next;

2998

#ifdef __GNUC__

2999

#pragma GCC diagnostic push

3000

#pragma GCC diagnostic ignored "-Wcast-qual"

3001

#endif

3002

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

3003

#ifdef __GNUC__

3004

#pragma GCC diagnostic pop

3005

#endif

3006

2385

free(mc.current_server);

3007

2386

mc.current_server = next;

3008

2387

}

3009

2388

}

3010

2389

3011

/* Re-raise privileges */

2390

/* Re-raise priviliges */

3012

2391

{

3013

ret = raise_privileges();

3014

if(ret != 0){

3015

errno = ret;

3016

perror_plus("Failed to raise privileges");

3017

} else {

3018

3019

/* Run network hooks */

3020

run_network_hooks("stop", interfaces_hooks != NULL ?

3021

interfaces_hooks : "", delay);

3022

3023

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

3024

{

3025

char *interface = NULL;

3026

while((interface=argz_next(interfaces_to_take_down,

3027

interfaces_to_take_down_size,

3028

interface))){

3029

ret = take_down_interface(interface);

3030

if(ret != 0){

3031

errno = ret;

3032

perror_plus("Failed to take down interface");

3033

}

3034

}

3035

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

3036

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

3037

" down\n");

3038

}

3039

}

3040

}

3041

3042

ret = lower_privileges_permanently();

3043

if(ret != 0){

3044

errno = ret;

3045

perror_plus("Failed to lower privileges permanently");

3046

}

2392

raise_privileges();

2393

2394

/* Run network hooks */

2395

run_network_hooks("stop", interfaces_hooks != NULL ?

2396

interfaces_hooks : "", delay);

2397

2398

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

2399

{

2400

char *interface = NULL;

2401

while((interface=argz_next(interfaces_to_take_down,

2402

interfaces_to_take_down_size,

2403

interface))){

2404

ret_errno = take_down_interface(interface);

2405

if(ret_errno != 0){

2406

errno = ret_errno;

2407

perror_plus("Failed to take down interface");

2408

}

2409

}

2410

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

2411

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

2412

" down\n");

2413

}

2414

}

2415

2416

lower_privileges_permanently();

3047

2417

}

3048

2418

3049

2419

free(interfaces_to_take_down);

3050

2420

free(interfaces_hooks);

3051

2421

3052

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

3053

uintmax_t level){

2422

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

2423

if(tempdir_created){

3054

2424

struct dirent **direntries = NULL;

3055

int dret;

3056

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

3057

O_RDONLY

3058

| O_NOFOLLOW

3059

| O_DIRECTORY

3060

| O_PATH));

3061

if(dir_fd == -1){

3062

perror_plus("open");

3063

}

3064

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

3065

notdotentries, alphasort);

3066

if(numentries >= 0){

2425

struct dirent *direntry = NULL;

2426

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

2427

alphasort);

2428

if (numentries > 0){

3067

2429

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

3068

if(debug){

3069

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

3070

dirname, direntries[i]->d_name);

3071

}

3072

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

3073

if(dret == -1){

3074

if(errno == EISDIR){

3075

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

3076

AT_REMOVEDIR);

3077

}

3078

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

3079

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

3080

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

3081

/* Recurse only in this special case */

3082

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

3083

dret = 0;

3084

}

3085

if(dret == -1){

3086

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

3087

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

3088

}

3089

}

3090

free(direntries[i]);

3091

}

3092

3093

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

3094

free(direntries);

3095

if(numentries == -1){

3096

perror_plus("scandirat");

3097

}

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

3108

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

3109

if(tempdir != NULL){

3110

clean_dir_at(-1, tempdir, 0);

2430

direntry = direntries[i];

2431

char *fullname = NULL;

2432

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

2433

direntry->d_name);

2434

if(ret < 0){

2435

perror_plus("asprintf");

2436

continue;

2437

}

2438

ret = remove(fullname);

2439

if(ret == -1){

2440

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

2441

strerror(errno));

2442

}

2443

free(fullname);

2444

}

2445

}

2446

2447

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

2448

free(direntries);

2449

if (numentries == -1){

2450

perror_plus("scandir");

2451

}

2452

ret = rmdir(tempdir);

2453

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

2454

perror_plus("rmdir");

2455

}

3111

2456

}

3112

2457

3113

2458

if(quit_now){