/mandos/release : revision 237.7.415

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

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

43

stdout, ferror() */

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> /* memset(), strcmp(), strlen(),

50

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

49

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

50

asprintf(), strncpy() */

51

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

52

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

53

sockaddr_in6, PF_INET6,

55

opendir(), DIR */

56

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

57

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

58

inet_pton(), connect() */

59

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

63

64

strtoimax() */

64

#include <assert.h> /* assert() */

65

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

65

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

66

EAI_SYSTEM, ENETUNREACH,

67

EHOSTUNREACH, ECONNREFUSED, EPROTO,

68

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

69

ENOTEMPTY,

66

70

program_invocation_short_name */

67

71

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

68

72

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

73

77

*/

74

78

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

75

79

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

76

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

77

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

80

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

81

unlinkat() */

82

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

78

83

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

79

84

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

80

85

argp_state, struct argp,

92

97

argz_delete(), argz_append(),

93

98

argz_stringify(), argz_add(),

94

99

argz_count() */

100

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

101

EAI_SYSTEM, gai_strerror() */

95

102

96

103

#ifdef __linux__

97

104

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

139

146

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

140

147

char *connect_to = NULL;

141

148

const char *hookdir = HOOKDIR;

149

int hookdir_fd = -1;

142

150

uid_t uid = 65534;

143

151

gid_t gid = 65534;

144

152

145

153

/* Doubly linked list that need to be circularly linked when used */

146

154

typedef struct server{

147

155

const char *ip;

148

uint16_t port;

156

in_port_t port;

149

157

AvahiIfIndex if_index;

150

158

int af;

151

159

struct timespec last_seen;

155

163

156

164

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

157

165

typedef struct {

158

AvahiSimplePoll *simple_poll;

159

166

AvahiServer *server;

160

167

gnutls_certificate_credentials_t cred;

161

168

unsigned int dh_bits;

163

170

const char *priority;

164

171

gpgme_ctx_t ctx;

165

172

server *current_server;

173

char *interfaces;

174

size_t interfaces_size;

166

175

} mandos_context;

167

176

168

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

169

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

170

.dh_bits = 1024, .priority = "SECURE256"

171

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

172

.current_server = NULL };

177

/* global so signal handler can reach it*/

178

AvahiSimplePoll *simple_poll;

173

179

174

180

sig_atomic_t quit_now = 0;

175

181

int signal_received = 0;

183

189

perror(print_text);

184

190

}

185

191

186

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

192

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

187

193

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

188

194

va_list ap;

189

195

va_start (ap, format);

190

196

191

197

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

192

198

program_invocation_short_name));

193

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

199

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

194

200

}

195

201

196

202

/*

198

204

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

199

205

* "buffer_length" is how much is already used.

200

206

*/

207

__attribute__((nonnull, warn_unused_result))

201

208

size_t incbuffer(char **buffer, size_t buffer_length,

202

209

size_t buffer_capacity){

203

210

if(buffer_length + BUFFER_SIZE > buffer_capacity){

204

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

205

if(buffer == NULL){

211

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

212

if(new_buf == NULL){

213

int old_errno = errno;

214

free(*buffer);

215

errno = old_errno;

216

*buffer = NULL;

206

217

return 0;

207

218

}

219

*buffer = new_buf;

208

220

buffer_capacity += BUFFER_SIZE;

209

221

}

210

222

return buffer_capacity;

211

223

}

212

224

213

225

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

214

bool add_server(const char *ip, uint16_t port, AvahiIfIndex if_index,

215

int af){

226

__attribute__((nonnull, warn_unused_result))

227

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

228

int af, server **current_server){

216

229

int ret;

217

230

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

218

231

if(new_server == NULL){

225

238

.af = af };

226

239

if(new_server->ip == NULL){

227

240

perror_plus("strdup");

241

free(new_server);

242

return false;

243

}

244

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

245

if(ret == -1){

246

perror_plus("clock_gettime");

247

#ifdef __GNUC__

248

#pragma GCC diagnostic push

249

#pragma GCC diagnostic ignored "-Wcast-qual"

250

#endif

251

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

252

#ifdef __GNUC__

253

#pragma GCC diagnostic pop

254

#endif

255

free(new_server);

228

256

return false;

229

257

}

230

258

/* Special case of first server */

231

if (mc.current_server == NULL){

259

if(*current_server == NULL){

232

260

new_server->next = new_server;

233

261

new_server->prev = new_server;

234

mc.current_server = new_server;

235

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

262

*current_server = new_server;

236

263

} else {

237

new_server->next = mc.current_server;

238

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

264

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

265

new_server->next = *current_server;

266

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

239

267

new_server->prev->next = new_server;

240

mc.current_server->prev = new_server;

241

}

242

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

243

if(ret == -1){

244

perror_plus("clock_gettime");

245

return false;

268

(*current_server)->prev = new_server;

246

269

}

247

270

return true;

248

271

}

250

273

/*

251

274

* Initialize GPGME.

252

275

*/

253

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

254

const char *tempdir){

276

__attribute__((nonnull, warn_unused_result))

277

static bool init_gpgme(const char * const seckey,

278

const char * const pubkey,

279

const char * const tempdir,

280

mandos_context *mc){

255

281

gpgme_error_t rc;

256

282

gpgme_engine_info_t engine_info;

257

283

258

259

284

/*

260

285

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

261

286

*/

262

bool import_key(const char *filename){

287

bool import_key(const char * const filename){

263

288

int ret;

264

289

int fd;

265

290

gpgme_data_t pgp_data;

277

302

return false;

278

303

}

279

304

280

rc = gpgme_op_import(mc.ctx, pgp_data);

305

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

281

306

if(rc != GPG_ERR_NO_ERROR){

282

307

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

283

308

gpgme_strsource(rc), gpgme_strerror(rc));

284

309

return false;

285

310

}

286

311

287

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

312

ret = close(fd);

288

313

if(ret == -1){

289

314

perror_plus("close");

290

315

}

327

352

}

328

353

329

354

/* Create new GPGME "context" */

330

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

355

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

331

356

if(rc != GPG_ERR_NO_ERROR){

332

357

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

333

358

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

346

371

* Decrypt OpenPGP data.

347

372

* Returns -1 on error

348

373

*/

374

__attribute__((nonnull, warn_unused_result))

349

375

static ssize_t pgp_packet_decrypt(const char *cryptotext,

350

376

size_t crypto_size,

351

char **plaintext){

377

char **plaintext,

378

mandos_context *mc){

352

379

gpgme_data_t dh_crypto, dh_plain;

353

380

gpgme_error_t rc;

354

381

ssize_t ret;

380

407

381

408

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

382

409

data buffer */

383

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

410

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

384

411

if(rc != GPG_ERR_NO_ERROR){

385

412

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

386

413

gpgme_strsource(rc), gpgme_strerror(rc));

387

414

plaintext_length = -1;

388

415

if(debug){

389

416

gpgme_decrypt_result_t result;

390

result = gpgme_op_decrypt_result(mc.ctx);

417

result = gpgme_op_decrypt_result(mc->ctx);

391

418

if(result == NULL){

392

419

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

393

420

} else {

470

497

return plaintext_length;

471

498

}

472

499

473

static const char * safer_gnutls_strerror(int value){

474

const char *ret = gnutls_strerror(value); /* Spurious warning from

475

-Wunreachable-code */

476

if(ret == NULL)

477

ret = "(unknown)";

478

return ret;

500

__attribute__((warn_unused_result, const))

501

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

502

if(str == NULL)

503

return "(unknown)";

504

return str;

505

}

506

507

__attribute__((warn_unused_result))

508

static const char *safer_gnutls_strerror(int value){

509

const char *ret = gnutls_strerror(value);

510

return safe_string(ret);

479

511

}

480

512

481

513

/* GnuTLS log function callback */

514

__attribute__((nonnull))

482

515

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

483

516

const char* string){

484

517

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

485

518

}

486

519

520

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

487

521

static int init_gnutls_global(const char *pubkeyfilename,

488

const char *seckeyfilename){

522

const char *seckeyfilename,

523

const char *dhparamsfilename,

524

mandos_context *mc){

489

525

int ret;

526

unsigned int uret;

490

527

491

528

if(debug){

492

529

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

493

530

}

494

531

495

ret = gnutls_global_init();

496

if(ret != GNUTLS_E_SUCCESS){

497

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

498

safer_gnutls_strerror(ret));

499

return -1;

500

}

501

502

532

if(debug){

503

533

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

504

534

* - GnuTLS manual

508

538

}

509

539

510

540

/* OpenPGP credentials */

511

ret = gnutls_certificate_allocate_credentials(&mc.cred);

541

ret = gnutls_certificate_allocate_credentials(&mc->cred);

512

542

if(ret != GNUTLS_E_SUCCESS){

513

543

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

514

544

safer_gnutls_strerror(ret));

515

gnutls_global_deinit();

516

545

return -1;

517

546

}

518

547

524

553

}

525

554

526

555

ret = gnutls_certificate_set_openpgp_key_file

527

(mc.cred, pubkeyfilename, seckeyfilename,

556

(mc->cred, pubkeyfilename, seckeyfilename,

528

557

GNUTLS_OPENPGP_FMT_BASE64);

529

558

if(ret != GNUTLS_E_SUCCESS){

530

559

fprintf_plus(stderr,

536

565

}

537

566

538

567

/* GnuTLS server initialization */

539

ret = gnutls_dh_params_init(&mc.dh_params);

568

ret = gnutls_dh_params_init(&mc->dh_params);

540

569

if(ret != GNUTLS_E_SUCCESS){

541

570

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

542

571

" initialization: %s\n",

543

572

safer_gnutls_strerror(ret));

544

573

goto globalfail;

545

574

}

546

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

547

if(ret != GNUTLS_E_SUCCESS){

548

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

549

safer_gnutls_strerror(ret));

550

goto globalfail;

551

}

552

553

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

575

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

576

if(dhparamsfilename != NULL){

577

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

578

do {

579

int dhpfile = open(dhparamsfilename, O_RDONLY);

580

if(dhpfile == -1){

581

perror_plus("open");

582

dhparamsfilename = NULL;

583

break;

584

}

585

size_t params_capacity = 0;

586

while(true){

587

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

588

(size_t)params.size,

589

(size_t)params_capacity);

590

if(params_capacity == 0){

591

perror_plus("incbuffer");

592

free(params.data);

593

params.data = NULL;

594

dhparamsfilename = NULL;

595

break;

596

}

597

ssize_t bytes_read = read(dhpfile,

598

params.data + params.size,

599

BUFFER_SIZE);

600

/* EOF */

601

if(bytes_read == 0){

602

break;

603

}

604

/* check bytes_read for failure */

605

if(bytes_read < 0){

606

perror_plus("read");

607

free(params.data);

608

params.data = NULL;

609

dhparamsfilename = NULL;

610

break;

611

}

612

params.size += (unsigned int)bytes_read;

613

}

614

if(params.data == NULL){

615

dhparamsfilename = NULL;

616

}

617

if(dhparamsfilename == NULL){

618

break;

619

}

620

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

621

GNUTLS_X509_FMT_PEM);

622

if(ret != GNUTLS_E_SUCCESS){

623

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

624

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

625

safer_gnutls_strerror(ret));

626

dhparamsfilename = NULL;

627

}

628

} while(false);

629

}

630

if(dhparamsfilename == NULL){

631

if(mc->dh_bits == 0){

632

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

633

/* Try to read the private key file */

634

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

635

do {

636

int secfile = open(seckeyfilename, O_RDONLY);

637

if(secfile == -1){

638

perror_plus("open");

639

break;

640

}

641

size_t buffer_capacity = 0;

642

while(true){

643

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

644

(size_t)buffer.size,

645

(size_t)buffer_capacity);

646

if(buffer_capacity == 0){

647

perror_plus("incbuffer");

648

free(buffer.data);

649

buffer.data = NULL;

650

break;

651

}

652

ssize_t bytes_read = read(secfile,

653

buffer.data + buffer.size,

654

BUFFER_SIZE);

655

/* EOF */

656

if(bytes_read == 0){

657

break;

658

}

659

/* check bytes_read for failure */

660

if(bytes_read < 0){

661

perror_plus("read");

662

free(buffer.data);

663

buffer.data = NULL;

664

break;

665

}

666

buffer.size += (unsigned int)bytes_read;

667

}

668

close(secfile);

669

} while(false);

670

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

671

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

672

if(buffer.data != NULL){

673

{

674

gnutls_openpgp_privkey_t privkey = NULL;

675

ret = gnutls_openpgp_privkey_init(&privkey);

676

if(ret != GNUTLS_E_SUCCESS){

677

fprintf_plus(stderr, "Error initializing OpenPGP key"

678

" structure: %s",

679

safer_gnutls_strerror(ret));

680

free(buffer.data);

681

buffer.data = NULL;

682

} else {

683

ret = gnutls_openpgp_privkey_import

684

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

685

if(ret != GNUTLS_E_SUCCESS){

686

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

687

safer_gnutls_strerror(ret));

688

privkey = NULL;

689

}

690

free(buffer.data);

691

buffer.data = NULL;

692

if(privkey != NULL){

693

/* Use private key to suggest an appropriate

694

sec_param */

695

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

696

gnutls_openpgp_privkey_deinit(privkey);

697

if(debug){

698

fprintf_plus(stderr, "This OpenPGP key implies using"

699

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

700

safe_string(gnutls_sec_param_get_name

701

(sec_param)));

702

}

703

}

704

}

705

}

706

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

707

/* Err on the side of caution */

708

sec_param = GNUTLS_SEC_PARAM_ULTRA;

709

if(debug){

710

fprintf_plus(stderr, "Falling back to security parameter"

711

" \"%s\"\n",

712

safe_string(gnutls_sec_param_get_name

713

(sec_param)));

714

}

715

}

716

}

717

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

718

if(uret != 0){

719

mc->dh_bits = uret;

720

if(debug){

721

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

722

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

723

safe_string(gnutls_sec_param_get_name

724

(sec_param)),

725

mc->dh_bits);

726

}

727

} else {

728

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

729

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

730

safe_string(gnutls_sec_param_get_name

731

(sec_param)),

732

safer_gnutls_strerror(ret));

733

goto globalfail;

734

}

735

} else if(debug){

736

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

737

mc->dh_bits);

738

}

739

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

740

if(ret != GNUTLS_E_SUCCESS){

741

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

742

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

743

safer_gnutls_strerror(ret));

744

goto globalfail;

745

}

746

}

747

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

554

748

555

749

return 0;

556

750

557

751

globalfail:

558

752

559

gnutls_certificate_free_credentials(mc.cred);

560

gnutls_global_deinit();

561

gnutls_dh_params_deinit(mc.dh_params);

753

gnutls_certificate_free_credentials(mc->cred);

754

gnutls_dh_params_deinit(mc->dh_params);

562

755

return -1;

563

756

}

564

757

565

static int init_gnutls_session(gnutls_session_t *session){

758

__attribute__((nonnull, warn_unused_result))

759

static int init_gnutls_session(gnutls_session_t *session,

760

mandos_context *mc){

566

761

int ret;

567

762

/* GnuTLS session creation */

568

763

do {

580

775

{

581

776

const char *err;

582

777

do {

583

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

778

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

584

779

if(quit_now){

585

780

gnutls_deinit(*session);

586

781

return -1;

597

792

598

793

do {

599

794

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

600

mc.cred);

795

mc->cred);

601

796

if(quit_now){

602

797

gnutls_deinit(*session);

603

798

return -1;

613

808

/* ignore client certificate if any. */

614

809

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

615

810

616

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

617

618

811

return 0;

619

812

}

620

813

622

815

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

623

816

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

624

817

818

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

819

__attribute__((warn_unused_result))

820

int raise_privileges(void){

821

int old_errno = errno;

822

int ret = 0;

823

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

824

ret = errno;

825

}

826

errno = old_errno;

827

return ret;

828

}

829

830

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

831

__attribute__((warn_unused_result))

832

int raise_privileges_permanently(void){

833

int old_errno = errno;

834

int ret = raise_privileges();

835

if(ret != 0){

836

errno = old_errno;

837

return ret;

838

}

839

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

840

ret = errno;

841

}

842

errno = old_errno;

843

return ret;

844

}

845

846

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

847

__attribute__((warn_unused_result))

848

int lower_privileges(void){

849

int old_errno = errno;

850

int ret = 0;

851

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

852

ret = errno;

853

}

854

errno = old_errno;

855

return ret;

856

}

857

858

/* Lower privileges permanently */

859

__attribute__((warn_unused_result))

860

int lower_privileges_permanently(void){

861

int old_errno = errno;

862

int ret = 0;

863

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

864

ret = errno;

865

}

866

errno = old_errno;

867

return ret;

868

}

869

870

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

871

__attribute__((nonnull, warn_unused_result))

872

static bool add_delete_local_route(const bool add,

873

const char *address,

874

AvahiIfIndex if_index){

875

int ret;

876

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

877

char add_arg[] = "add";

878

char delete_arg[] = "delete";

879

char debug_flag[] = "--debug";

880

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

881

if(pluginhelperdir == NULL){

882

if(debug){

883

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

884

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

885

}

886

return false;

887

}

888

889

char interface[IF_NAMESIZE];

890

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

891

perror_plus("if_indextoname");

892

return false;

893

}

894

895

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

896

if(devnull == -1){

897

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

898

return false;

899

}

900

pid_t pid = fork();

901

if(pid == 0){

902

/* Child */

903

/* Raise privileges */

904

errno = raise_privileges_permanently();

905

if(errno != 0){

906

perror_plus("Failed to raise privileges");

907

/* _exit(EX_NOPERM); */

908

} else {

909

/* Set group */

910

errno = 0;

911

ret = setgid(0);

912

if(ret == -1){

913

perror_plus("setgid");

914

_exit(EX_NOPERM);

915

}

916

/* Reset supplementary groups */

917

errno = 0;

918

ret = setgroups(0, NULL);

919

if(ret == -1){

920

perror_plus("setgroups");

921

_exit(EX_NOPERM);

922

}

923

}

924

ret = dup2(devnull, STDIN_FILENO);

925

if(ret == -1){

926

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

927

_exit(EX_OSERR);

928

}

929

ret = close(devnull);

930

if(ret == -1){

931

perror_plus("close");

932

_exit(EX_OSERR);

933

}

934

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

935

if(ret == -1){

936

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

937

_exit(EX_OSERR);

938

}

939

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

940

O_RDONLY

941

| O_DIRECTORY

942

| O_PATH

943

| O_CLOEXEC));

944

if(helperdir_fd == -1){

945

perror_plus("open");

946

_exit(EX_UNAVAILABLE);

947

}

948

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

949

helper, O_RDONLY));

950

if(helper_fd == -1){

951

perror_plus("openat");

952

close(helperdir_fd);

953

_exit(EX_UNAVAILABLE);

954

}

955

close(helperdir_fd);

956

#ifdef __GNUC__

957

#pragma GCC diagnostic push

958

#pragma GCC diagnostic ignored "-Wcast-qual"

959

#endif

960

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

961

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

962

interface, debug ? debug_flag : NULL, NULL },

963

environ) == -1){

964

#ifdef __GNUC__

965

#pragma GCC diagnostic pop

966

#endif

967

perror_plus("fexecve");

968

_exit(EXIT_FAILURE);

969

}

970

}

971

if(pid == -1){

972

perror_plus("fork");

973

return false;

974

}

975

int status;

976

pid_t pret = -1;

977

errno = 0;

978

do {

979

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

980

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

981

int errno_raising = 0;

982

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

983

errno_raising = errno;

984

perror_plus("Failed to raise privileges in order to"

985

" kill helper program");

986

}

987

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

988

perror_plus("kill");

989

}

990

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

991

perror_plus("Failed to lower privileges after killing"

992

" helper program");

993

}

994

return false;

995

}

996

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

997

if(pret == -1){

998

perror_plus("waitpid");

999

return false;

1000

}

1001

if(WIFEXITED(status)){

1002

if(WEXITSTATUS(status) != 0){

1003

fprintf_plus(stderr, "Error: iprouteadddel exited"

1004

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

1005

return false;

1006

}

1007

return true;

1008

}

1009

if(WIFSIGNALED(status)){

1010

fprintf_plus(stderr, "Error: iprouteadddel died by"

1011

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

1012

return false;

1013

}

1014

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

1015

return false;

1016

}

1017

1018

__attribute__((nonnull, warn_unused_result))

1019

static bool add_local_route(const char *address,

1020

AvahiIfIndex if_index){

1021

if(debug){

1022

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

1023

}

1024

return add_delete_local_route(true, address, if_index);

1025

}

1026

1027

__attribute__((nonnull, warn_unused_result))

1028

static bool delete_local_route(const char *address,

1029

AvahiIfIndex if_index){

1030

if(debug){

1031

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

1032

}

1033

return add_delete_local_route(false, address, if_index);

1034

}

1035

625

1036

/* Called when a Mandos server is found */

626

static int start_mandos_communication(const char *ip, uint16_t port,

1037

__attribute__((nonnull, warn_unused_result))

1038

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

627

1039

AvahiIfIndex if_index,

628

int af){

1040

int af, mandos_context *mc){

629

1041

int ret, tcp_sd = -1;

630

1042

ssize_t sret;

631

union {

632

struct sockaddr_in in;

633

struct sockaddr_in6 in6;

634

} to;

1043

struct sockaddr_storage to;

635

1044

char *buffer = NULL;

636

1045

char *decrypted_buffer = NULL;

637

1046

size_t buffer_length = 0;

640

1049

int retval = -1;

641

1050

gnutls_session_t session;

642

1051

int pf; /* Protocol family */

1052

bool route_added = false;

643

1053

644

1054

errno = 0;

645

1055

661

1071

return -1;

662

1072

}

663

1073

664

ret = init_gnutls_session(&session);

1074

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

1075

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

1076

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

1077

bool match = false;

1078

{

1079

char *interface = NULL;

1080

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

1081

interface))){

1082

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

1083

match = true;

1084

break;

1085

}

1086

}

1087

}

1088

if(not match){

1089

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

1090

connect to the server */

1091

if(debug){

1092

char interface[IF_NAMESIZE];

1093

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

1094

perror_plus("if_indextoname");

1095

} else {

1096

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

1097

" \"%s\"\n",

1098

if_indextoname((unsigned int)if_index,

1099

interface));

1100

}

1101

}

1102

return -1;

1103

}

1104

}

1105

1106

ret = init_gnutls_session(&session, mc);

665

1107

if(ret != 0){

666

1108

return -1;

667

1109

}

668

1110

669

1111

if(debug){

670

1112

fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"

671

PRIu16 "\n", ip, port);

1113

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

672

1114

}

673

1115

674

tcp_sd = socket(pf, SOCK_STREAM, 0);

1116

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

675

1117

if(tcp_sd < 0){

676

1118

int e = errno;

677

1119

perror_plus("socket");

684

1126

goto mandos_end;

685

1127

}

686

1128

687

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

688

1129

if(af == AF_INET6){

689

to.in6.sin6_family = (sa_family_t)af;

690

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

1130

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

1131

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

1132

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

691

1133

} else { /* IPv4 */

692

to.in.sin_family = (sa_family_t)af;

693

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

1134

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

1135

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

1136

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

694

1137

}

695

1138

if(ret < 0 ){

696

1139

int e = errno;

705

1148

goto mandos_end;

706

1149

}

707

1150

if(af == AF_INET6){

708

to.in6.sin6_port = htons(port); /* Spurious warnings from

709

-Wconversion and

710

-Wunreachable-code */

711

712

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

713

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

714

-Wunreachable-code*/

1151

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

1152

if(IN6_IS_ADDR_LINKLOCAL

1153

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

715

1154

if(if_index == AVAHI_IF_UNSPEC){

716

1155

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

717

1156

" incomplete without a network interface\n");

719

1158

goto mandos_end;

720

1159

}

721

1160

/* Set the network interface number as scope */

722

to.in6.sin6_scope_id = (uint32_t)if_index;

1161

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

723

1162

}

724

1163

} else {

725

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

726

-Wconversion and

727

-Wunreachable-code */

1164

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

728

1165

}

729

1166

730

1167

if(quit_now){

738

1175

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

739

1176

perror_plus("if_indextoname");

740

1177

} else {

741

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16

742

"\n", ip, interface, port);

1178

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX

1179

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

743

1180

}

744

1181

} else {

745

fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",

746

ip, port);

1182

fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",

1183

ip, (uintmax_t)port);

747

1184

}

748

1185

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

749

1186

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

750

const char *pcret;

751

if(af == AF_INET6){

752

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

753

sizeof(addrstr));

754

} else {

755

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

756

sizeof(addrstr));

757

}

758

if(pcret == NULL){

759

perror_plus("inet_ntop");

760

} else {

761

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

762

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

763

}

764

}

765

}

766

767

if(quit_now){

768

errno = EINTR;

769

goto mandos_end;

770

}

771

772

if(af == AF_INET6){

773

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

774

} else {

775

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

776

}

777

if(ret < 0){

778

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

779

int e = errno;

780

perror_plus("connect");

781

errno = e;

782

}

783

goto mandos_end;

784

}

785

786

if(quit_now){

787

errno = EINTR;

788

goto mandos_end;

1187

if(af == AF_INET6){

1188

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

1189

sizeof(struct sockaddr_in6),

1190

addrstr, sizeof(addrstr), NULL, 0,

1191

NI_NUMERICHOST);

1192

} else {

1193

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

1194

sizeof(struct sockaddr_in),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

}

1198

if(ret == EAI_SYSTEM){

1199

perror_plus("getnameinfo");

1200

} else if(ret != 0) {

1201

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

1202

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

1203

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

1204

}

1205

}

1206

1207

if(quit_now){

1208

errno = EINTR;

1209

goto mandos_end;

1210

}

1211

1212

while(true){

1213

if(af == AF_INET6){

1214

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

1215

sizeof(struct sockaddr_in6));

1216

} else {

1217

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

1218

sizeof(struct sockaddr_in));

1219

}

1220

if(ret < 0){

1221

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

1222

and if_index != AVAHI_IF_UNSPEC

1223

and connect_to == NULL

1224

and not route_added and

1225

((af == AF_INET6 and not

1226

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1227

&to)->sin6_addr)))

1228

or (af == AF_INET and

1229

/* Not a a IPv4LL address */

1230

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

1231

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

1232

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

1233

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

1234

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

1235

connect to a Mandos server announced by Avahi on a server

1236

host with a global address. Work around this by retrying

1237

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

1238

1239

Avahi bug reference:

1240

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

1241

https://bugs.debian.org/587961

1242

*/

1243

if(debug){

1244

fprintf_plus(stderr, "Mandos server unreachable, trying"

1245

" direct route\n");

1246

}

1247

int e = errno;

1248

route_added = add_local_route(ip, if_index);

1249

if(route_added){

1250

continue;

1251

}

1252

errno = e;

1253

}

1254

if(errno != ECONNREFUSED or debug){

1255

int e = errno;

1256

perror_plus("connect");

1257

errno = e;

1258

}

1259

goto mandos_end;

1260

}

1261

1262

if(quit_now){

1263

errno = EINTR;

1264

goto mandos_end;

1265

}

1266

break;

789

1267

}

790

1268

791

1269

const char *out = mandos_protocol_version;

942

1420

if(buffer_length > 0){

943

1421

ssize_t decrypted_buffer_size;

944

1422

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

945

&decrypted_buffer);

1423

&decrypted_buffer, mc);

946

1424

if(decrypted_buffer_size >= 0){

947

1425

1426

clearerr(stdout);

948

1427

written = 0;

949

1428

while(written < (size_t) decrypted_buffer_size){

950

1429

if(quit_now){

966

1445

}

967

1446

written += (size_t)ret;

968

1447

}

1448

ret = fflush(stdout);

1449

if(ret != 0){

1450

int e = errno;

1451

if(debug){

1452

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

1453

strerror(errno));

1454

}

1455

errno = e;

1456

goto mandos_end;

1457

}

969

1458

retval = 0;

970

1459

}

971

1460

}

974

1463

975

1464

mandos_end:

976

1465

{

1466

if(route_added){

1467

if(not delete_local_route(ip, if_index)){

1468

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

1469

" interface %d", ip, if_index);

1470

}

1471

}

977

1472

int e = errno;

978

1473

free(decrypted_buffer);

979

1474

free(buffer);

980

1475

if(tcp_sd >= 0){

981

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

1476

ret = close(tcp_sd);

982

1477

}

983

1478

if(ret == -1){

984

1479

if(e == 0){

996

1491

return retval;

997

1492

}

998

1493

1494

__attribute__((nonnull))

999

1495

static void resolve_callback(AvahiSServiceResolver *r,

1000

1496

AvahiIfIndex interface,

1001

1497

AvahiProtocol proto,

1009

1505

AVAHI_GCC_UNUSED AvahiStringList *txt,

1010

1506

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1011

1507

flags,

1012

AVAHI_GCC_UNUSED void* userdata){

1013

assert(r);

1508

void *mc){

1509

if(r == NULL){

1510

return;

1511

}

1014

1512

1015

1513

/* Called whenever a service has been resolved successfully or

1016

1514

timed out */

1017

1515

1018

1516

if(quit_now){

1517

avahi_s_service_resolver_free(r);

1019

1518

return;

1020

1519

}

1021

1520

1025

1524

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

1026

1525

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

1027

1526

domain,

1028

avahi_strerror(avahi_server_errno(mc.server)));

1527

avahi_strerror(avahi_server_errno

1528

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

1029

1529

break;

1030

1530

1031

1531

case AVAHI_RESOLVER_FOUND:

1037

1537

PRIdMAX ") on port %" PRIu16 "\n", name,

1038

1538

host_name, ip, (intmax_t)interface, port);

1039

1539

}

1040

int ret = start_mandos_communication(ip, port, interface,

1041

avahi_proto_to_af(proto));

1540

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

1541

interface,

1542

avahi_proto_to_af(proto),

1543

mc);

1042

1544

if(ret == 0){

1043

avahi_simple_poll_quit(mc.simple_poll);

1545

avahi_simple_poll_quit(simple_poll);

1044

1546

} else {

1045

if(not add_server(ip, port, interface,

1046

avahi_proto_to_af(proto))){

1547

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

1548

avahi_proto_to_af(proto),

1549

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

1047

1550

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

1048

1551

" list\n", name);

1049

1552

}

1062

1565

const char *domain,

1063

1566

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1064

1567

flags,

1065

AVAHI_GCC_UNUSED void* userdata){

1066

assert(b);

1568

void *mc){

1569

if(b == NULL){

1570

return;

1571

}

1067

1572

1068

1573

/* Called whenever a new services becomes available on the LAN or

1069

1574

is removed from the LAN */

1077

1582

case AVAHI_BROWSER_FAILURE:

1078

1583

1079

1584

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1585

avahi_strerror(avahi_server_errno

1586

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

1587

avahi_simple_poll_quit(simple_poll);

1082

1588

return;

1083

1589

1084

1590

case AVAHI_BROWSER_NEW:

1087

1593

the callback function is called the Avahi server will free the

1088

1594

resolver for us. */

1089

1595

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1596

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

1597

interface, protocol, name, type,

1598

domain, protocol, 0,

1599

resolve_callback, mc) == NULL)

1093

1600

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

1094

1601

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1602

avahi_strerror(avahi_server_errno

1603

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

1096

1604

break;

1097

1605

1098

1606

case AVAHI_BROWSER_REMOVE:

1117

1625

signal_received = sig;

1118

1626

int old_errno = errno;

1119

1627

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1628

if(simple_poll != NULL){

1629

avahi_simple_poll_quit(simple_poll);

1122

1630

}

1123

1631

errno = old_errno;

1124

1632

}

1125

1633

1634

__attribute__((nonnull, warn_unused_result))

1126

1635

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

1127

1636

int ret;

1128

error_t ret_errno;

1637

int old_errno;

1129

1638

1130

1639

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

1131

1640

if(s < 0){

1132

ret_errno = errno;

1641

old_errno = errno;

1133

1642

perror_plus("socket");

1134

errno = ret_errno;

1643

errno = old_errno;

1135

1644

return false;

1136

1645

}

1137

strcpy(ifr->ifr_name, ifname);

1646

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

1647

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

1138

1648

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1139

1649

if(ret == -1){

1140

1650

if(debug){

1141

ret_errno = errno;

1651

old_errno = errno;

1142

1652

perror_plus("ioctl SIOCGIFFLAGS");

1143

errno = ret_errno;

1653

errno = old_errno;

1144

1654

}

1145

1655

return false;

1146

1656

}

1147

1657

return true;

1148

1658

}

1149

1659

1660

__attribute__((nonnull, warn_unused_result))

1150

1661

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

1151

1662

1152

1663

/* Reject the loopback device */

1194

1705

* corresponds to an acceptable network device.

1195

1706

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

1196

1707

*/

1708

__attribute__((nonnull, warn_unused_result))

1197

1709

int good_interface(const struct dirent *if_entry){

1198

1710

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

1199

1711

return 0;

1217

1729

/*

1218

1730

* This function determines if a network interface is up.

1219

1731

*/

1732

__attribute__((nonnull, warn_unused_result))

1220

1733

bool interface_is_up(const char *interface){

1221

1734

struct ifreq ifr;

1222

1735

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

1233

1746

/*

1234

1747

* This function determines if a network interface is running

1235

1748

*/

1749

__attribute__((nonnull, warn_unused_result))

1236

1750

bool interface_is_running(const char *interface){

1237

1751

struct ifreq ifr;

1238

1752

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

1246

1760

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

1247

1761

}

1248

1762

1763

__attribute__((nonnull, pure, warn_unused_result))

1249

1764

int notdotentries(const struct dirent *direntry){

1250

1765

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

1251

1766

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

1258

1773

}

1259

1774

1260

1775

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

1776

__attribute__((nonnull, warn_unused_result))

1261

1777

int runnable_hook(const struct dirent *direntry){

1262

1778

int ret;

1263

1779

size_t sret;

1271

1787

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

1272

1788

"abcdefghijklmnopqrstuvwxyz"

1273

1789

"0123456789"

1274

"_-");

1790

"_.-");

1275

1791

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

1276

1792

/* Contains non-allowed characters */

1277

1793

if(debug){

1281

1797

return 0;

1282

1798

}

1283

1799

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);

1800

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

1292

1801

if(ret == -1){

1293

1802

if(debug){

1294

1803

perror_plus("Could not stat hook");

1318

1827

return 1;

1319

1828

}

1320

1829

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1830

__attribute__((nonnull, warn_unused_result))

1831

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1832

mandos_context *mc){

1322

1833

int ret;

1323

1834

struct timespec now;

1324

1835

struct timespec waited_time;

1325

1836

intmax_t block_time;

1326

1837

1327

1838

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1839

if(mc->current_server == NULL){

1840

if(debug){

1330

1841

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

1331

1842

" No timeout!\n");

1332

1843

}

1333

1844

ret = avahi_simple_poll_iterate(s, -1);

1334

1845

} else {

1335

if (debug){

1846

if(debug){

1336

1847

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

1337

1848

" it, or wait\n");

1338

1849

}

1345

1856

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

1346

1857

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

1347

1858

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1859

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

1349

1860

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1861

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

1351

1862

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

1352

1863

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

1353

1864

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

1355

1866

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

1356

1867

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

1357

1868

1358

if (debug){

1869

if(debug){

1359

1870

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

1360

1871

block_time);

1361

1872

}

1362

1873

1363

1874

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);

1875

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

1876

mc->current_server->port,

1877

mc->current_server->if_index,

1878

mc->current_server->af, mc);

1368

1879

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1880

avahi_simple_poll_quit(s);

1370

1881

return 0;

1371

1882

}

1372

1883

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1884

&mc->current_server->last_seen);

1374

1885

if(ret == -1){

1375

1886

perror_plus("clock_gettime");

1376

1887

return -1;

1377

1888

}

1378

mc.current_server = mc.current_server->next;

1889

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

1379

1890

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

1380

1891

servers, but don't block */

1381

1892

}

1383

1894

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

1384

1895

}

1385

1896

if(ret != 0){

1386

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

1897

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

1387

1898

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

1388

1899

}

1389

1900

}

1390

1901

}

1391

1902

}

1392

1903

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,

1904

__attribute__((nonnull))

1905

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

1446

1906

const float delay){

1447

struct dirent **direntries;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

1907

struct dirent **direntries = NULL;

1908

if(hookdir_fd == -1){

1909

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1910

| O_CLOEXEC);

1911

if(hookdir_fd == -1){

1912

if(errno == ENOENT){

1913

if(debug){

1914

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

1915

" found\n", hookdir);

1916

}

1917

} else {

1918

perror_plus("open");

1919

}

1920

return;

1921

}

1922

}

1923

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

1924

runnable_hook, alphasort);

1452

1925

if(numhooks == -1){

1453

1926

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){

1927

return;

1928

}

1929

struct dirent *direntry;

1930

int ret;

1931

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

1932

if(devnull == -1){

1933

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

1934

return;

1935

}

1936

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

1937

direntry = direntries[i];

1938

if(debug){

1939

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

1940

direntry->d_name);

1941

}

1942

pid_t hook_pid = fork();

1943

if(hook_pid == 0){

1944

/* Child */

1945

/* Raise privileges */

1946

errno = raise_privileges_permanently();

1947

if(errno != 0){

1948

perror_plus("Failed to raise privileges");

1949

_exit(EX_NOPERM);

1950

}

1951

/* Set group */

1952

errno = 0;

1953

ret = setgid(0);

1954

if(ret == -1){

1955

perror_plus("setgid");

1956

_exit(EX_NOPERM);

1957

}

1958

/* Reset supplementary groups */

1959

errno = 0;

1960

ret = setgroups(0, NULL);

1961

if(ret == -1){

1962

perror_plus("setgroups");

1963

_exit(EX_NOPERM);

1964

}

1965

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

1966

if(ret == -1){

1967

perror_plus("setenv");

1968

_exit(EX_OSERR);

1969

}

1970

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

1971

if(ret == -1){

1972

perror_plus("setenv");

1973

_exit(EX_OSERR);

1974

}

1975

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

1976

if(ret == -1){

1977

perror_plus("setenv");

1978

_exit(EX_OSERR);

1979

}

1980

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

1981

if(ret == -1){

1982

perror_plus("setenv");

1983

_exit(EX_OSERR);

1984

}

1985

char *delaystring;

1986

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

1987

if(ret == -1){

1461

1988

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

}

1989

_exit(EX_OSERR);

1990

}

1991

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

1992

if(ret == -1){

1520

1993

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

}

1994

perror_plus("setenv");

1995

_exit(EX_OSERR);

1996

}

1997

free(delaystring);

1998

if(connect_to != NULL){

1999

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

2000

if(ret == -1){

2001

perror_plus("setenv");

2002

_exit(EX_OSERR);

2003

}

2004

}

2005

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

2006

direntry->d_name,

2007

O_RDONLY));

2008

if(hook_fd == -1){

2009

perror_plus("openat");

2010

_exit(EXIT_FAILURE);

2011

}

2012

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

2013

perror_plus("close");

2014

_exit(EXIT_FAILURE);

2015

}

2016

ret = dup2(devnull, STDIN_FILENO);

2017

if(ret == -1){

2018

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

2019

_exit(EX_OSERR);

2020

}

2021

ret = close(devnull);

2022

if(ret == -1){

2023

perror_plus("close");

2024

_exit(EX_OSERR);

2025

}

2026

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2027

if(ret == -1){

2028

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

2029

_exit(EX_OSERR);

2030

}

2031

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

2032

environ) == -1){

2033

perror_plus("fexecve");

2034

_exit(EXIT_FAILURE);

2035

}

2036

} else {

2037

if(hook_pid == -1){

2038

perror_plus("fork");

2039

free(direntry);

2040

continue;

2041

}

2042

int status;

2043

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

2044

perror_plus("waitpid");

2045

free(direntry);

2046

continue;

2047

}

2048

if(WIFEXITED(status)){

2049

if(WEXITSTATUS(status) != 0){

2050

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

2051

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

2052

WEXITSTATUS(status));

2053

free(direntry);

2054

continue;

2055

}

2056

} else if(WIFSIGNALED(status)){

2057

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

2058

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

2059

WTERMSIG(status));

2060

free(direntry);

2061

continue;

1532

2062

} 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;

2063

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

2064

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

2065

free(direntry);

2066

continue;

2067

}

2068

}

2069

if(debug){

2070

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

2071

direntry->d_name);

2072

}

2073

free(direntry);

2074

}

2075

free(direntries);

2076

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

2077

perror_plus("close");

2078

} else {

2079

hookdir_fd = -1;

2080

}

2081

close(devnull);

1569

2082

}

1570

2083

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;

2084

__attribute__((nonnull, warn_unused_result))

2085

int bring_up_interface(const char *const interface,

2086

const float delay){

2087

int old_errno = errno;

2088

int ret;

1577

2089

struct ifreq network;

1578

2090

unsigned int if_index = if_nametoindex(interface);

1579

2091

if(if_index == 0){

1588

2100

}

1589

2101

1590

2102

if(not interface_is_up(interface)){

1591

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

2103

int ret_errno = 0;

2104

int ioctl_errno = 0;

2105

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

1592

2106

ret_errno = errno;

1593

2107

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

1594

2108

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

2109

errno = old_errno;

1595

2110

return ret_errno;

1596

2111

}

1597

network.ifr_flags |= IFF_UP;

2112

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

1598

2113

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

2114

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

2115

if(sd == -1){

1601

2116

ret_errno = errno;

1602

2117

perror_plus("socket");

1603

2118

errno = old_errno;

1604

2119

return ret_errno;

1605

2120

}

1606

2121

1607

2122

if(quit_now){

1608

close(sd);

2123

ret = close(sd);

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

1609

2127

errno = old_errno;

1610

2128

return EINTR;

1611

2129

}

1615

2133

interface);

1616

2134

}

1617

2135

1618

/* Raise priviliges */

1619

raise_privileges();

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

1620

2142

1621

2143

#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");

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

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

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

1629

2155

}

1630

2156

#endif /* __linux__ */

1631

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

1632

ret_errno = errno;

2157

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

2158

ioctl_errno = errno;

1633

2159

#ifdef __linux__

1634

2160

if(restore_loglevel){

1635

2161

ret_linux = klogctl(7, NULL, 0);

1639

2165

}

1640

2166

#endif /* __linux__ */

1641

2167

1642

/* Lower privileges */

1643

lower_privileges();

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

1644

2177

1645

2178

/* Close the socket */

1646

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

2179

ret = close(sd);

1647

2180

if(ret == -1){

1648

2181

perror_plus("close");

1649

2182

}

1650

2183

1651

2184

if(ret_setflags == -1){

1652

errno = ret_errno;

2185

errno = ioctl_errno;

1653

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1654

2187

errno = old_errno;

1655

return ret_errno;

2188

return ioctl_errno;

1656

2189

}

1657

2190

} else if(debug){

1658

2191

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

1676

2209

return 0;

1677

2210

}

1678

2211

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;

2212

__attribute__((nonnull, warn_unused_result))

2213

int take_down_interface(const char *const interface){

2214

int old_errno = errno;

1684

2215

struct ifreq network;

1685

2216

unsigned int if_index = if_nametoindex(interface);

1686

2217

if(if_index == 0){

1689

2220

return ENXIO;

1690

2221

}

1691

2222

if(interface_is_up(interface)){

2223

int ret_errno = 0;

2224

int ioctl_errno = 0;

1692

2225

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

1693

2226

ret_errno = errno;

1694

2227

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

1695

2228

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

2229

errno = old_errno;

1696

2230

return ret_errno;

1697

2231

}

1698

2232

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

1699

2233

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

2234

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

2235

if(sd == -1){

1702

2236

ret_errno = errno;

1703

2237

perror_plus("socket");

1704

2238

errno = old_errno;

1710

2244

interface);

1711

2245

}

1712

2246

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();

2247

/* Raise privileges */

2248

ret_errno = raise_privileges();

2249

if(ret_errno != 0){

2250

errno = ret_errno;

2251

perror_plus("Failed to raise privileges");

2252

}

2253

2254

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

2255

ioctl_errno = errno;

2256

2257

/* If raise_privileges() succeeded above */

2258

if(ret_errno == 0){

2259

/* Lower privileges */

2260

ret_errno = lower_privileges();

2261

if(ret_errno != 0){

2262

errno = ret_errno;

2263

perror_plus("Failed to lower privileges");

2264

}

2265

}

1721

2266

1722

2267

/* Close the socket */

1723

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

2268

int ret = close(sd);

1724

2269

if(ret == -1){

1725

2270

perror_plus("close");

1726

2271

}

1727

2272

1728

2273

if(ret_setflags == -1){

1729

errno = ret_errno;

2274

errno = ioctl_errno;

1730

2275

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1731

2276

errno = old_errno;

1732

return ret_errno;

2277

return ioctl_errno;

1733

2278

}

1734

2279

} else if(debug){

1735

2280

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

1741

2286

}

1742

2287

1743

2288

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

2289

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

2290

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

2291

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

2292

.current_server = NULL, .interfaces = NULL,

2293

.interfaces_size = 0 };

1744

2294

AvahiSServiceBrowser *sb = NULL;

1745

2295

error_t ret_errno;

1746

2296

int ret;

1747

2297

intmax_t tmpmax;

1748

2298

char *tmp;

1749

2299

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

1752

2300

char *interfaces_to_take_down = NULL;

1753

2301

size_t interfaces_to_take_down_size = 0;

1754

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

1755

bool tempdir_created = false;

2302

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

2303

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

2304

char *tempdir = NULL;

1756

2305

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1757

2306

const char *seckey = PATHDIR "/" SECKEY;

1758

2307

const char *pubkey = PATHDIR "/" PUBKEY;

2308

const char *dh_params_file = NULL;

1759

2309

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

1761

2310

1762

2311

bool gnutls_initialized = false;

1763

2312

bool gpgme_initialized = false;

1815

2364

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

1816

2365

" Diffie-Hellman key exchange",

1817

2366

.group = 2 },

2367

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

2368

.arg = "FILE",

2369

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

2370

" for the Diffie-Hellman key exchange",

2371

.group = 2 },

1818

2372

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

1819

2373

.arg = "STRING",

1820

2374

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

1854

2408

connect_to = arg;

1855

2409

break;

1856

2410

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

1857

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

1858

(int)',');

2411

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

2412

arg, (int)',');

1859

2413

if(ret_errno != 0){

1860

2414

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

1861

2415

}

1875

2429

}

1876

2430

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

1877

2431

break;

2432

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

2433

dh_params_file = arg;

2434

break;

1878

2435

case 130: /* --priority */

1879

2436

mc.priority = arg;

1880

2437

break;

1920

2477

.args_doc = "",

1921

2478

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

1922

2479

" passwords from a Mandos server" };

1923

ret = argp_parse(&argp, argc, argv,

1924

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1925

switch(ret){

2480

ret_errno = argp_parse(&argp, argc, argv,

2481

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2482

switch(ret_errno){

1926

2483

case 0:

1927

2484

break;

1928

2485

case ENOMEM:

1929

2486

default:

1930

errno = ret;

2487

errno = ret_errno;

1931

2488

perror_plus("argp_parse");

1932

2489

exitcode = EX_OSERR;

1933

2490

goto end;

1936

2493

goto end;

1937

2494

}

1938

2495

}

1939

2496

1940

2497

{

1941

2498

/* Work around Debian bug #633582:

1942

2499

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

1943

2500

1944

/* Re-raise priviliges */

1945

if(raise_privileges() == 0){

2501

/* Re-raise privileges */

2502

ret = raise_privileges();

2503

if(ret != 0){

2504

errno = ret;

2505

perror_plus("Failed to raise privileges");

2506

} else {

1946

2507

struct stat st;

1947

2508

1948

2509

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

1962

2523

}

1963

2524

}

1964

2525

}

1965

TEMP_FAILURE_RETRY(close(seckey_fd));

2526

close(seckey_fd);

1966

2527

}

1967

2528

}

1968

2529

1969

2530

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

1970

2531

int pubkey_fd = open(pubkey, O_RDONLY);

1971

2532

if(pubkey_fd == -1){

1983

2544

}

1984

2545

}

1985

2546

}

1986

TEMP_FAILURE_RETRY(close(pubkey_fd));

1987

}

1988

}

1989

2547

close(pubkey_fd);

2548

}

2549

}

2550

2551

if(dh_params_file != NULL

2552

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

2553

int dhparams_fd = open(dh_params_file, O_RDONLY);

2554

if(dhparams_fd == -1){

2555

perror_plus("open");

2556

} else {

2557

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

2558

if(ret == -1){

2559

perror_plus("fstat");

2560

} else {

2561

if(S_ISREG(st.st_mode)

2562

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

2563

ret = fchown(dhparams_fd, uid, gid);

2564

if(ret == -1){

2565

perror_plus("fchown");

2566

}

2567

}

2568

}

2569

close(dhparams_fd);

2570

}

2571

}

2572

1990

2573

/* Lower privileges */

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2574

ret = lower_privileges();

2575

if(ret != 0){

2576

errno = ret;

2577

perror_plus("Failed to lower privileges");

1995

2578

}

1996

2579

}

1997

2580

}

1998

2581

1999

/* Remove empty interface names */

2582

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

2000

2583

{

2001

2584

char *interface = NULL;

2002

while((interface = argz_next(interfaces, interfaces_size,

2585

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

2003

2586

interface))){

2004

if(if_nametoindex(interface) == 0){

2005

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

2587

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

2588

and if_nametoindex(interface) == 0){

2589

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

2006

2590

fprintf_plus(stderr, "Not using nonexisting interface"

2007

2591

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

2008

2592

}

2009

argz_delete(&interfaces, &interfaces_size, interface);

2593

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

2010

2594

interface = NULL;

2011

2595

}

2012

2596

}

2014

2598

2015

2599

/* Run network hooks */

2016

2600

{

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

}

2601

if(mc.interfaces != NULL){

2602

interfaces_hooks = malloc(mc.interfaces_size);

2603

if(interfaces_hooks == NULL){

2604

perror_plus("malloc");

2605

goto end;

2606

}

2607

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

2608

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

2609

}

2610

run_network_hooks("start", interfaces_hooks != NULL ?

2611

interfaces_hooks : "", delay);

2028

2612

}

2029

2613

2030

2614

if(not debug){

2035

2619

from the signal handler */

2036

2620

/* Initialize the pseudo-RNG for Avahi */

2037

2621

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

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2622

simple_poll = avahi_simple_poll_new();

2623

if(simple_poll == NULL){

2040

2624

fprintf_plus(stderr,

2041

2625

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

2042

2626

exitcode = EX_UNAVAILABLE;

2107

2691

}

2108

2692

2109

2693

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

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2694

if(mc.interfaces == NULL){

2695

struct dirent **direntries = NULL;

2112

2696

/* Look for any good interfaces */

2113

2697

ret = scandir(sys_class_net, &direntries, good_interface,

2114

2698

alphasort);

2115

2699

if(ret >= 1){

2116

2700

/* Add all found interfaces to interfaces list */

2117

2701

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2702

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

2119

2703

direntries[i]->d_name);

2120

2704

if(ret_errno != 0){

2705

errno = ret_errno;

2121

2706

perror_plus("argz_add");

2707

free(direntries[i]);

2122

2708

continue;

2123

2709

}

2124

2710

if(debug){

2125

2711

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

2126

2712

direntries[i]->d_name);

2127

2713

}

2714

free(direntries[i]);

2128

2715

}

2129

2716

free(direntries);

2130

2717

} else {

2131

free(direntries);

2718

if(ret == 0){

2719

free(direntries);

2720

}

2132

2721

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

2133

2722

exitcode = EXIT_FAILURE;

2134

2723

goto end;

2135

2724

}

2136

2725

}

2137

2726

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)){

2727

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

2728

{

2150

2729

char *interface = NULL;

2151

while((interface = argz_next(interfaces, interfaces_size,

2730

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

2152

2731

interface))){

2732

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

2733

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

2734

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

2735

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

2736

interface);

2737

interface = NULL;

2738

while((interface = argz_next(mc.interfaces,

2739

mc.interfaces_size, interface))){

2740

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

2741

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

2742

interface);

2743

interface = NULL;

2744

}

2745

}

2746

break;

2747

}

2153

2748

bool interface_was_up = interface_is_up(interface);

2154

ret = bring_up_interface(interface, delay);

2749

errno = bring_up_interface(interface, delay);

2155

2750

if(not interface_was_up){

2156

if(ret != 0){

2157

errno = ret;

2158

perror_plus("Failed to bring up interface");

2751

if(errno != 0){

2752

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

2753

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

2159

2754

} else {

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

interface);

2755

errno = argz_add(&interfaces_to_take_down,

2756

&interfaces_to_take_down_size,

2757

interface);

2758

if(errno != 0){

2759

perror_plus("argz_add");

2760

}

2163

2761

}

2164

2762

}

2165

2763

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2169

2764

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

2170

2765

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

2171

2766

}

2172

2767

}

2173

2768

2769

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

2770

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

2771

if(debug){

2772

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

2773

mc.interfaces);

2774

}

2775

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

2776

}

2777

2174

2778

if(quit_now){

2175

2779

goto end;

2176

2780

}

2177

2781

2178

ret = init_gnutls_global(pubkey, seckey);

2782

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

2179

2783

if(ret == -1){

2180

2784

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

2181

2785

exitcode = EX_UNAVAILABLE;

2188

2792

goto end;

2189

2793

}

2190

2794

2191

if(mkdtemp(tempdir) == NULL){

2795

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

2796

tempdir = mkdtemp(run_tempdir);

2797

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

2798

if(debug){

2799

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

2800

run_tempdir, old_tempdir);

2801

}

2802

tempdir = mkdtemp(old_tempdir);

2803

}

2804

if(tempdir == NULL){

2192

2805

perror_plus("mkdtemp");

2193

2806

goto end;

2194

2807

}

2195

tempdir_created = true;

2196

2808

2197

2809

if(quit_now){

2198

2810

goto end;

2199

2811

}

2200

2812

2201

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

2813

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

2202

2814

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

2203

2815

exitcode = EX_UNAVAILABLE;

2204

2816

goto end;

2225

2837

goto end;

2226

2838

}

2227

2839

2228

uint16_t port;

2840

in_port_t port;

2229

2841

errno = 0;

2230

2842

tmpmax = strtoimax(address+1, &tmp, 10);

2231

2843

if(errno != 0 or tmp == address+1 or *tmp != '\0'

2232

or tmpmax != (uint16_t)tmpmax){

2844

or tmpmax != (in_port_t)tmpmax){

2233

2845

fprintf_plus(stderr, "Bad port number\n");

2234

2846

exitcode = EX_USAGE;

2235

2847

goto end;

2236

2848

}

2237

2849

2238

2850

if(quit_now){

2239

2851

goto end;

2240

2852

}

2241

2853

2242

port = (uint16_t)tmpmax;

2854

port = (in_port_t)tmpmax;

2243

2855

*address = '\0';

2244

2856

/* Colon in address indicates IPv6 */

2245

2857

int af;

2261

2873

}

2262

2874

2263

2875

while(not quit_now){

2264

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

2876

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

2877

&mc);

2265

2878

if(quit_now or ret == 0){

2266

2879

break;

2267

2880

}

2269

2882

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

2270

2883

(int)retry_interval);

2271

2884

}

2272

sleep((int)retry_interval);

2885

sleep((unsigned int)retry_interval);

2273

2886

}

2274

2887

2275

if (not quit_now){

2888

if(not quit_now){

2276

2889

exitcode = EXIT_SUCCESS;

2277

2890

}

2278

2891

2293

2906

config.publish_domain = 0;

2294

2907

2295

2908

/* Allocate a new server */

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2909

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2910

&config, NULL, NULL, &ret);

2299

2911

2300

2912

/* Free the Avahi configuration data */

2301

2913

avahi_server_config_free(&config);

2304

2916

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

2305

2917

if(mc.server == NULL){

2306

2918

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

2307

avahi_strerror(ret_errno));

2919

avahi_strerror(ret));

2308

2920

exitcode = EX_UNAVAILABLE;

2309

2921

goto end;

2310

2922

}

2316

2928

/* Create the Avahi service browser */

2317

2929

sb = avahi_s_service_browser_new(mc.server, if_index,

2318

2930

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2319

NULL, 0, browse_callback, NULL);

2931

NULL, 0, browse_callback,

2932

(void *)&mc);

2320

2933

if(sb == NULL){

2321

2934

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

2322

2935

avahi_strerror(avahi_server_errno(mc.server)));

2333

2946

if(debug){

2334

2947

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

2335

2948

}

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2949

2950

ret = avahi_loop_with_timeout(simple_poll,

2951

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

2339

2952

if(debug){

2340

2953

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

2341

2954

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

2348

2961

}

2349

2962

2350

2963

/* Cleanup things */

2964

free(mc.interfaces);

2965

2351

2966

if(sb != NULL)

2352

2967

avahi_s_service_browser_free(sb);

2353

2968

2354

2969

if(mc.server != NULL)

2355

2970

avahi_server_free(mc.server);

2356

2971

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2972

if(simple_poll != NULL)

2973

avahi_simple_poll_free(simple_poll);

2359

2974

2360

2975

if(gnutls_initialized){

2361

2976

gnutls_certificate_free_credentials(mc.cred);

2362

gnutls_global_deinit();

2363

2977

gnutls_dh_params_deinit(mc.dh_params);

2364

2978

}

2365

2979

2373

2987

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

2374

2988

while(mc.current_server != NULL){

2375

2989

server *next = mc.current_server->next;

2990

#ifdef __GNUC__

2991

#pragma GCC diagnostic push

2992

#pragma GCC diagnostic ignored "-Wcast-qual"

2993

#endif

2994

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

2995

#ifdef __GNUC__

2996

#pragma GCC diagnostic pop

2997

#endif

2376

2998

free(mc.current_server);

2377

2999

mc.current_server = next;

2378

3000

}

2379

3001

}

2380

3002

2381

/* Re-raise priviliges */

3003

/* Re-raise privileges */

2382

3004

{

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();

3005

ret = raise_privileges();

3006

if(ret != 0){

3007

errno = ret;

3008

perror_plus("Failed to raise privileges");

3009

} else {

3010

3011

/* Run network hooks */

3012

run_network_hooks("stop", interfaces_hooks != NULL ?

3013

interfaces_hooks : "", delay);

3014

3015

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

3016

{

3017

char *interface = NULL;

3018

while((interface=argz_next(interfaces_to_take_down,

3019

interfaces_to_take_down_size,

3020

interface))){

3021

ret = take_down_interface(interface);

3022

if(ret != 0){

3023

errno = ret;

3024

perror_plus("Failed to take down interface");

3025

}

3026

}

3027

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

3028

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

3029

" down\n");

3030

}

3031

}

3032

}

3033

3034

ret = lower_privileges_permanently();

3035

if(ret != 0){

3036

errno = ret;

3037

perror_plus("Failed to lower privileges permanently");

3038

}

2407

3039

}

2408

3040

2409

3041

free(interfaces_to_take_down);

2410

3042

free(interfaces_hooks);

2411

3043

3044

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

3045

uintmax_t level){

3046

struct dirent **direntries = NULL;

3047

int dret;

3048

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

3049

O_RDONLY

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(dir_fd == -1){

3054

perror_plus("open");

3055

}

3056

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

3057

notdotentries, alphasort);

3058

if(numentries >= 0){

3059

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

3060

if(debug){

3061

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

3062

dirname, direntries[i]->d_name);

3063

}

3064

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

3065

if(dret == -1){

3066

if(errno == EISDIR){

3067

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

3068

AT_REMOVEDIR);

3069

}

3070

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

3071

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

3072

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

3073

/* Recurse only in this special case */

3074

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

3075

dret = 0;

3076

}

3077

if(dret == -1){

3078

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

3079

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

3080

}

3081

}

3082

free(direntries[i]);

3083

}

3084

3085

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

3086

free(direntries);

3087

if(numentries == -1){

3088

perror_plus("scandirat");

3089

}

3090

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3091

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

3092

perror_plus("rmdir");

3093

}

3094

} else {

3095

perror_plus("scandirat");

3096

}

3097

close(dir_fd);

3098

}

3099

2412

3100

/* 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

}

3101

if(tempdir != NULL){

3102

clean_dir_at(-1, tempdir, 0);

2446

3103

}

2447

3104

2448

3105

if(quit_now){