/mandos/trunk : revision 774

9

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

10

*

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* Everything else is

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13

12

13

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*

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* 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() */

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42

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

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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(),

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strtof(), abort() */

48

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

49

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

50

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

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

50

asprintf(), strcpy() */

51

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

52

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

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sockaddr_in6, PF_INET6,

55

opendir(), DIR */

56

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

57

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

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inet_pton(), connect() */

59

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

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inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

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62

*/

62

63

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

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73

*/

73

74

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

74

75

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

75

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

76

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

76

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

77

unlinkat() */

78

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

77

79

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

78

80

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

79

81

argp_state, struct argp,

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93

argz_delete(), argz_append(),

92

94

argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

141

146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

154

159

155

160

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

156

161

typedef struct {

157

AvahiSimplePoll *simple_poll;

158

162

AvahiServer *server;

159

163

gnutls_certificate_credentials_t cred;

160

164

unsigned int dh_bits;

162

166

const char *priority;

163

167

gpgme_ctx_t ctx;

164

168

server *current_server;

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char *interfaces;

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size_t interfaces_size;

165

171

} mandos_context;

166

172

167

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

168

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

169

.dh_bits = 1024, .priority = "SECURE256"

170

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

171

.current_server = NULL };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

172

175

173

176

sig_atomic_t quit_now = 0;

174

177

int signal_received = 0;

182

185

perror(print_text);

183

186

}

184

187

185

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

188

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

186

189

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

187

190

va_list ap;

188

191

va_start (ap, format);

189

192

190

193

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

191

194

program_invocation_short_name));

192

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

195

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

193

196

}

194

197

195

198

/*

197

200

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

198

201

* "buffer_length" is how much is already used.

199

202

*/

203

__attribute__((nonnull, warn_unused_result))

200

204

size_t incbuffer(char **buffer, size_t buffer_length,

201

205

size_t buffer_capacity){

202

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

203

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

204

if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

205

213

return 0;

206

214

}

215

*buffer = new_buf;

207

216

buffer_capacity += BUFFER_SIZE;

208

217

}

209

218

return buffer_capacity;

210

219

}

211

220

212

221

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

222

__attribute__((nonnull, warn_unused_result))

213

223

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

214

int af){

224

int af, server **current_server){

215

225

int ret;

216

226

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

217

227

if(new_server == NULL){

224

234

.af = af };

225

235

if(new_server->ip == NULL){

226

236

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

227

252

return false;

228

253

}

229

254

/* Special case of first server */

230

if (mc.current_server == NULL){

255

if(*current_server == NULL){

231

256

new_server->next = new_server;

232

257

new_server->prev = new_server;

233

mc.current_server = new_server;

234

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

258

*current_server = new_server;

235

259

} else {

236

new_server->next = mc.current_server;

237

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

260

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

261

new_server->next = *current_server;

262

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

238

263

new_server->prev->next = new_server;

239

mc.current_server->prev = new_server;

240

}

241

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

242

if(ret == -1){

243

perror_plus("clock_gettime");

244

return false;

264

(*current_server)->prev = new_server;

245

265

}

246

266

return true;

247

267

}

249

269

/*

250

270

* Initialize GPGME.

251

271

*/

252

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

253

const char *tempdir){

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

254

277

gpgme_error_t rc;

255

278

gpgme_engine_info_t engine_info;

256

279

257

258

280

/*

259

281

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

260

282

*/

261

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

262

284

int ret;

263

285

int fd;

264

286

gpgme_data_t pgp_data;

276

298

return false;

277

299

}

278

300

279

rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

280

302

if(rc != GPG_ERR_NO_ERROR){

281

303

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

282

304

gpgme_strsource(rc), gpgme_strerror(rc));

283

305

return false;

284

306

}

285

307

286

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

308

ret = close(fd);

287

309

if(ret == -1){

288

310

perror_plus("close");

289

311

}

326

348

}

327

349

328

350

/* Create new GPGME "context" */

329

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

351

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

330

352

if(rc != GPG_ERR_NO_ERROR){

331

353

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

332

354

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

345

367

* Decrypt OpenPGP data.

346

368

* Returns -1 on error

347

369

*/

370

__attribute__((nonnull, warn_unused_result))

348

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

349

372

size_t crypto_size,

350

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

351

375

gpgme_data_t dh_crypto, dh_plain;

352

376

gpgme_error_t rc;

353

377

ssize_t ret;

379

403

380

404

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

381

405

data buffer */

382

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

406

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

383

407

if(rc != GPG_ERR_NO_ERROR){

384

408

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

385

409

gpgme_strsource(rc), gpgme_strerror(rc));

386

410

plaintext_length = -1;

387

411

if(debug){

388

412

gpgme_decrypt_result_t result;

389

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

390

414

if(result == NULL){

391

415

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

392

416

} else {

469

493

return plaintext_length;

470

494

}

471

495

472

static const char * safer_gnutls_strerror(int value){

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

473

505

const char *ret = gnutls_strerror(value);

474

if(ret == NULL)

475

ret = "(unknown)";

476

return ret;

506

return safe_string(ret);

477

507

}

478

508

479

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

480

511

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

481

512

const char* string){

482

513

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

483

514

}

484

515

516

__attribute__((nonnull, warn_unused_result))

485

517

static int init_gnutls_global(const char *pubkeyfilename,

486

const char *seckeyfilename){

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

487

521

int ret;

522

unsigned int uret;

488

523

489

524

if(debug){

490

525

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

506

541

}

507

542

508

543

/* OpenPGP credentials */

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

510

545

if(ret != GNUTLS_E_SUCCESS){

511

546

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

512

547

safer_gnutls_strerror(ret));

522

557

}

523

558

524

559

ret = gnutls_certificate_set_openpgp_key_file

525

(mc.cred, pubkeyfilename, seckeyfilename,

560

(mc->cred, pubkeyfilename, seckeyfilename,

526

561

GNUTLS_OPENPGP_FMT_BASE64);

527

562

if(ret != GNUTLS_E_SUCCESS){

528

563

fprintf_plus(stderr,

534

569

}

535

570

536

571

/* GnuTLS server initialization */

537

ret = gnutls_dh_params_init(&mc.dh_params);

572

ret = gnutls_dh_params_init(&mc->dh_params);

538

573

if(ret != GNUTLS_E_SUCCESS){

539

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

540

575

" initialization: %s\n",

541

576

safer_gnutls_strerror(ret));

542

577

goto globalfail;

543

578

}

544

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

545

if(ret != GNUTLS_E_SUCCESS){

546

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

547

safer_gnutls_strerror(ret));

548

goto globalfail;

549

}

550

551

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

579

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

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

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

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

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

628

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

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

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

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

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

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

751

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

552

752

553

753

return 0;

554

754

555

755

globalfail:

556

756

557

gnutls_certificate_free_credentials(mc.cred);

757

gnutls_certificate_free_credentials(mc->cred);

558

758

gnutls_global_deinit();

559

gnutls_dh_params_deinit(mc.dh_params);

759

gnutls_dh_params_deinit(mc->dh_params);

560

760

return -1;

561

761

}

562

762

563

static int init_gnutls_session(gnutls_session_t *session){

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

564

766

int ret;

565

767

/* GnuTLS session creation */

566

768

do {

578

780

{

579

781

const char *err;

580

782

do {

581

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

783

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

582

784

if(quit_now){

583

785

gnutls_deinit(*session);

584

786

return -1;

595

797

596

798

do {

597

799

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

598

mc.cred);

800

mc->cred);

599

801

if(quit_now){

600

802

gnutls_deinit(*session);

601

803

return -1;

611

813

/* ignore client certificate if any. */

612

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

815

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

615

616

816

return 0;

617

817

}

618

818

620

820

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

621

821

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

622

822

823

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

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

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

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

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

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

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

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

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

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

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

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

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

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

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

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

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

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

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

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

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

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

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

901

if(devnull == -1){

902

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

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

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

932

_exit(EX_OSERR);

933

}

934

ret = close(devnull);

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

_exit(EX_UNAVAILABLE);

958

}

959

close(helperdir_fd);

960

#ifdef __GNUC__

961

#pragma GCC diagnostic push

962

#pragma GCC diagnostic ignored "-Wcast-qual"

963

#endif

964

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

965

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

966

interface, debug ? debug_flag : NULL, NULL },

967

environ) == -1){

968

#ifdef __GNUC__

969

#pragma GCC diagnostic pop

970

#endif

971

perror_plus("fexecve");

972

_exit(EXIT_FAILURE);

973

}

974

}

975

if(pid == -1){

976

perror_plus("fork");

977

return false;

978

}

979

int status;

980

pid_t pret = -1;

981

errno = 0;

982

do {

983

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

984

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

985

int errno_raising = 0;

986

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

987

errno_raising = errno;

988

perror_plus("Failed to raise privileges in order to"

989

" kill helper program");

990

}

991

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

992

perror_plus("kill");

993

}

994

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

995

perror_plus("Failed to lower privileges after killing"

996

" helper program");

997

}

998

return false;

999

}

1000

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

1001

if(pret == -1){

1002

perror_plus("waitpid");

1003

return false;

1004

}

1005

if(WIFEXITED(status)){

1006

if(WEXITSTATUS(status) != 0){

1007

fprintf_plus(stderr, "Error: iprouteadddel exited"

1008

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

1009

return false;

1010

}

1011

return true;

1012

}

1013

if(WIFSIGNALED(status)){

1014

fprintf_plus(stderr, "Error: iprouteadddel died by"

1015

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

1016

return false;

1017

}

1018

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

1019

return false;

1020

}

1021

1022

__attribute__((nonnull, warn_unused_result))

1023

static bool add_local_route(const char *address,

1024

AvahiIfIndex if_index){

1025

if(debug){

1026

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

1027

}

1028

return add_delete_local_route(true, address, if_index);

1029

}

1030

1031

__attribute__((nonnull, warn_unused_result))

1032

static bool delete_local_route(const char *address,

1033

AvahiIfIndex if_index){

1034

if(debug){

1035

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

1036

}

1037

return add_delete_local_route(false, address, if_index);

1038

}

1039

623

1040

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

624

1042

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

625

1043

AvahiIfIndex if_index,

626

int af){

1044

int af, mandos_context *mc){

627

1045

int ret, tcp_sd = -1;

628

1046

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1047

struct sockaddr_storage to;

633

1048

char *buffer = NULL;

634

1049

char *decrypted_buffer = NULL;

635

1050

size_t buffer_length = 0;

638

1053

int retval = -1;

639

1054

gnutls_session_t session;

640

1055

int pf; /* Protocol family */

1056

bool route_added = false;

641

1057

642

1058

errno = 0;

643

1059

659

1075

return -1;

660

1076

}

661

1077

662

ret = init_gnutls_session(&session);

1078

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

1079

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

1080

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

1081

bool match = false;

1082

{

1083

char *interface = NULL;

1084

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

1085

interface))){

1086

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

1087

match = true;

1088

break;

1089

}

1090

}

1091

}

1092

if(not match){

1093

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

1094

connect to the server */

1095

if(debug){

1096

char interface[IF_NAMESIZE];

1097

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

1098

perror_plus("if_indextoname");

1099

} else {

1100

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

1101

" \"%s\"\n",

1102

if_indextoname((unsigned int)if_index,

1103

interface));

1104

}

1105

}

1106

return -1;

1107

}

1108

}

1109

1110

ret = init_gnutls_session(&session, mc);

663

1111

if(ret != 0){

664

1112

return -1;

665

1113

}

669

1117

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

670

1118

}

671

1119

672

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

673

1121

if(tcp_sd < 0){

674

1122

int e = errno;

675

1123

perror_plus("socket");

682

1130

goto mandos_end;

683

1131

}

684

1132

685

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

686

1133

if(af == AF_INET6){

687

to.in6.sin6_family = (sa_family_t)af;

688

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

1134

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

1135

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

1136

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

689

1137

} else { /* IPv4 */

690

to.in.sin_family = (sa_family_t)af;

691

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

1138

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

1139

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

1140

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

692

1141

}

693

1142

if(ret < 0 ){

694

1143

int e = errno;

703

1152

goto mandos_end;

704

1153

}

705

1154

if(af == AF_INET6){

706

to.in6.sin6_port = htons(port);

707

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

708

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

709

-Wunreachable-code*/

1155

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

1156

if(IN6_IS_ADDR_LINKLOCAL

1157

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

710

1158

if(if_index == AVAHI_IF_UNSPEC){

711

1159

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

712

1160

" incomplete without a network interface\n");

714

1162

goto mandos_end;

715

1163

}

716

1164

/* Set the network interface number as scope */

717

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

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

718

1166

}

719

1167

} else {

720

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

721

-Wconversion and

722

-Wunreachable-code */

1168

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

723

1169

}

724

1170

725

1171

if(quit_now){

742

1188

}

743

1189

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

744

1190

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

745

const char *pcret;

746

if(af == AF_INET6){

747

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

748

sizeof(addrstr));

749

} else {

750

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

751

sizeof(addrstr));

752

}

753

if(pcret == NULL){

754

perror_plus("inet_ntop");

755

} else {

756

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

757

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

758

}

759

}

760

}

761

762

if(quit_now){

763

errno = EINTR;

764

goto mandos_end;

765

}

766

767

if(af == AF_INET6){

768

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

769

} else {

770

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

771

}

772

if(ret < 0){

773

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

774

int e = errno;

775

perror_plus("connect");

776

errno = e;

777

}

778

goto mandos_end;

779

}

780

781

if(quit_now){

782

errno = EINTR;

783

goto mandos_end;

1191

if(af == AF_INET6){

1192

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

1193

sizeof(struct sockaddr_in6),

1194

addrstr, sizeof(addrstr), NULL, 0,

1195

NI_NUMERICHOST);

1196

} else {

1197

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

1198

sizeof(struct sockaddr_in),

1199

addrstr, sizeof(addrstr), NULL, 0,

1200

NI_NUMERICHOST);

1201

}

1202

if(ret == EAI_SYSTEM){

1203

perror_plus("getnameinfo");

1204

} else if(ret != 0) {

1205

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

1206

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

1207

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

1208

}

1209

}

1210

1211

if(quit_now){

1212

errno = EINTR;

1213

goto mandos_end;

1214

}

1215

1216

while(true){

1217

if(af == AF_INET6){

1218

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

1219

sizeof(struct sockaddr_in6));

1220

} else {

1221

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

1222

sizeof(struct sockaddr_in));

1223

}

1224

if(ret < 0){

1225

if(errno == ENETUNREACH

1226

and if_index != AVAHI_IF_UNSPEC

1227

and connect_to == NULL

1228

and not route_added and

1229

((af == AF_INET6 and not

1230

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1231

&to)->sin6_addr)))

1232

or (af == AF_INET and

1233

/* Not a a IPv4LL address */

1234

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

1235

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

1236

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

1237

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

1238

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

1239

connect to a Mandos server announced by Avahi on a server

1240

host with a global address. Work around this by retrying

1241

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

1242

1243

Avahi bug reference:

1244

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

1245

https://bugs.debian.org/587961

1246

*/

1247

if(debug){

1248

fprintf_plus(stderr, "Mandos server unreachable, trying"

1249

" direct route\n");

1250

}

1251

int e = errno;

1252

route_added = add_local_route(ip, if_index);

1253

if(route_added){

1254

continue;

1255

}

1256

errno = e;

1257

}

1258

if(errno != ECONNREFUSED or debug){

1259

int e = errno;

1260

perror_plus("connect");

1261

errno = e;

1262

}

1263

goto mandos_end;

1264

}

1265

1266

if(quit_now){

1267

errno = EINTR;

1268

goto mandos_end;

1269

}

1270

break;

784

1271

}

785

1272

786

1273

const char *out = mandos_protocol_version;

937

1424

if(buffer_length > 0){

938

1425

ssize_t decrypted_buffer_size;

939

1426

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

940

&decrypted_buffer);

1427

&decrypted_buffer, mc);

941

1428

if(decrypted_buffer_size >= 0){

942

1429

943

1430

written = 0;

969

1456

970

1457

mandos_end:

971

1458

{

1459

if(route_added){

1460

if(not delete_local_route(ip, if_index)){

1461

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

1462

" interface %d", ip, if_index);

1463

}

1464

}

972

1465

int e = errno;

973

1466

free(decrypted_buffer);

974

1467

free(buffer);

975

1468

if(tcp_sd >= 0){

976

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

1469

ret = close(tcp_sd);

977

1470

}

978

1471

if(ret == -1){

979

1472

if(e == 0){

991

1484

return retval;

992

1485

}

993

1486

1487

__attribute__((nonnull))

994

1488

static void resolve_callback(AvahiSServiceResolver *r,

995

1489

AvahiIfIndex interface,

996

1490

AvahiProtocol proto,

1004

1498

AVAHI_GCC_UNUSED AvahiStringList *txt,

1005

1499

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1006

1500

flags,

1007

AVAHI_GCC_UNUSED void* userdata){

1501

void *mc){

1008

1502

if(r == NULL){

1009

1503

return;

1010

1504

}

1013

1507

timed out */

1014

1508

1015

1509

if(quit_now){

1510

avahi_s_service_resolver_free(r);

1016

1511

return;

1017

1512

}

1018

1513

1022

1517

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

1023

1518

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

1024

1519

domain,

1025

avahi_strerror(avahi_server_errno(mc.server)));

1520

avahi_strerror(avahi_server_errno

1521

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

1026

1522

break;

1027

1523

1028

1524

case AVAHI_RESOLVER_FOUND:

1036

1532

}

1037

1533

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

1038

1534

interface,

1039

avahi_proto_to_af(proto));

1535

avahi_proto_to_af(proto),

1536

mc);

1040

1537

if(ret == 0){

1041

avahi_simple_poll_quit(mc.simple_poll);

1538

avahi_simple_poll_quit(simple_poll);

1042

1539

} else {

1043

1540

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

1044

avahi_proto_to_af(proto))){

1541

avahi_proto_to_af(proto),

1542

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

1045

1543

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

1046

1544

" list\n", name);

1047

1545

}

1060

1558

const char *domain,

1061

1559

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1062

1560

flags,

1063

AVAHI_GCC_UNUSED void* userdata){

1561

void *mc){

1064

1562

if(b == NULL){

1065

1563

return;

1066

1564

}

1077

1575

case AVAHI_BROWSER_FAILURE:

1078

1576

1079

1577

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1578

avahi_strerror(avahi_server_errno

1579

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

1580

avahi_simple_poll_quit(simple_poll);

1082

1581

return;

1083

1582

1084

1583

case AVAHI_BROWSER_NEW:

1087

1586

the callback function is called the Avahi server will free the

1088

1587

resolver for us. */

1089

1588

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1589

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

1590

interface, protocol, name, type,

1591

domain, protocol, 0,

1592

resolve_callback, mc) == NULL)

1093

1593

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

1094

1594

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1595

avahi_strerror(avahi_server_errno

1596

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

1096

1597

break;

1097

1598

1098

1599

case AVAHI_BROWSER_REMOVE:

1117

1618

signal_received = sig;

1118

1619

int old_errno = errno;

1119

1620

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1621

if(simple_poll != NULL){

1622

avahi_simple_poll_quit(simple_poll);

1122

1623

}

1123

1624

errno = old_errno;

1124

1625

}

1125

1626

1627

__attribute__((nonnull, warn_unused_result))

1126

1628

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

1127

1629

int ret;

1128

1630

error_t ret_errno;

1147

1649

return true;

1148

1650

}

1149

1651

1652

__attribute__((nonnull, warn_unused_result))

1150

1653

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

1151

1654

1152

1655

/* Reject the loopback device */

1194

1697

* corresponds to an acceptable network device.

1195

1698

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

1196

1699

*/

1700

__attribute__((nonnull, warn_unused_result))

1197

1701

int good_interface(const struct dirent *if_entry){

1198

1702

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

1199

1703

return 0;

1217

1721

/*

1218

1722

* This function determines if a network interface is up.

1219

1723

*/

1724

__attribute__((nonnull, warn_unused_result))

1220

1725

bool interface_is_up(const char *interface){

1221

1726

struct ifreq ifr;

1222

1727

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

1233

1738

/*

1234

1739

* This function determines if a network interface is running

1235

1740

*/

1741

__attribute__((nonnull, warn_unused_result))

1236

1742

bool interface_is_running(const char *interface){

1237

1743

struct ifreq ifr;

1238

1744

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

1246

1752

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

1247

1753

}

1248

1754

1755

__attribute__((nonnull, pure, warn_unused_result))

1249

1756

int notdotentries(const struct dirent *direntry){

1250

1757

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

1251

1758

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

1258

1765

}

1259

1766

1260

1767

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

1768

__attribute__((nonnull, warn_unused_result))

1261

1769

int runnable_hook(const struct dirent *direntry){

1262

1770

int ret;

1263

1771

size_t sret;

1271

1779

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

1272

1780

"abcdefghijklmnopqrstuvwxyz"

1273

1781

"0123456789"

1274

"_-");

1782

"_.-");

1275

1783

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

1276

1784

/* Contains non-allowed characters */

1277

1785

if(debug){

1281

1789

return 0;

1282

1790

}

1283

1791

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);

1792

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

1292

1793

if(ret == -1){

1293

1794

if(debug){

1294

1795

perror_plus("Could not stat hook");

1318

1819

return 1;

1319

1820

}

1320

1821

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1822

__attribute__((nonnull, warn_unused_result))

1823

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1824

mandos_context *mc){

1322

1825

int ret;

1323

1826

struct timespec now;

1324

1827

struct timespec waited_time;

1325

1828

intmax_t block_time;

1326

1829

1327

1830

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1831

if(mc->current_server == NULL){

1832

if(debug){

1330

1833

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

1331

1834

" No timeout!\n");

1332

1835

}

1333

1836

ret = avahi_simple_poll_iterate(s, -1);

1334

1837

} else {

1335

if (debug){

1838

if(debug){

1336

1839

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

1337

1840

" it, or wait\n");

1338

1841

}

1345

1848

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

1346

1849

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

1347

1850

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1851

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

1349

1852

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1853

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

1351

1854

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

1352

1855

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

1353

1856

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

1355

1858

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

1356

1859

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

1357

1860

1358

if (debug){

1861

if(debug){

1359

1862

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

1360

1863

block_time);

1361

1864

}

1362

1865

1363

1866

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);

1867

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

1868

mc->current_server->port,

1869

mc->current_server->if_index,

1870

mc->current_server->af, mc);

1368

1871

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1872

avahi_simple_poll_quit(s);

1370

1873

return 0;

1371

1874

}

1372

1875

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1876

&mc->current_server->last_seen);

1374

1877

if(ret == -1){

1375

1878

perror_plus("clock_gettime");

1376

1879

return -1;

1377

1880

}

1378

mc.current_server = mc.current_server->next;

1881

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

1379

1882

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

1380

1883

servers, but don't block */

1381

1884

}

1383

1886

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

1384

1887

}

1385

1888

if(ret != 0){

1386

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

1889

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

1387

1890

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

1388

1891

}

1389

1892

}

1390

1893

}

1391

1894

}

1392

1895

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,

1896

__attribute__((nonnull))

1897

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

1446

1898

const float delay){

1447

struct dirent **direntries;

1899

struct dirent **direntries = NULL;

1900

if(hookdir_fd == -1){

1901

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1902

| O_CLOEXEC);

1903

if(hookdir_fd == -1){

1904

if(errno == ENOENT){

1905

if(debug){

1906

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

1907

" found\n", hookdir);

1908

}

1909

} else {

1910

perror_plus("open");

1911

}

1912

return;

1913

}

1914

}

1915

#ifdef __GLIBC__

1916

#if __GLIBC_PREREQ(2, 15)

1917

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

1918

runnable_hook, alphasort);

1919

#else /* not __GLIBC_PREREQ(2, 15) */

1920

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

1921

alphasort);

1922

#endif /* not __GLIBC_PREREQ(2, 15) */

1923

#else /* not __GLIBC__ */

1924

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

1925

alphasort);

1926

#endif /* not __GLIBC__ */

1927

if(numhooks == -1){

1928

perror_plus("scandir");

1929

return;

1930

}

1448

1931

struct dirent *direntry;

1449

1932

int ret;

1450

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

1451

alphasort);

1452

if(numhooks == -1){

1453

if(errno == ENOENT){

1454

if(debug){

1455

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

1456

" found\n", hookdir);

1457

}

1458

} else {

1459

perror_plus("scandir");

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);

1460

1943

}

1461

} else {

1462

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

1463

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

1464

direntry = direntries[i];

1465

char *fullname = NULL;

1466

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

1467

if(ret < 0){

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){

1468

1990

perror_plus("asprintf");

1469

continue;

1470

}

1471

if(debug){

1472

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

1473

direntry->d_name);

1474

}

1475

pid_t hook_pid = fork();

1476

if(hook_pid == 0){

1477

/* Child */

1478

/* Raise privileges */

1479

raise_privileges_permanently();

1480

/* Set group */

1481

errno = 0;

1482

ret = setgid(0);

1483

if(ret == -1){

1484

perror_plus("setgid");

1485

}

1486

/* Reset supplementary groups */

1487

errno = 0;

1488

ret = setgroups(0, NULL);

1489

if(ret == -1){

1490

perror_plus("setgroups");

1491

}

1492

dup2(devnull, STDIN_FILENO);

1493

close(devnull);

1494

dup2(STDERR_FILENO, STDOUT_FILENO);

1495

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

1496

if(ret == -1){

1497

perror_plus("setenv");

1498

_exit(EX_OSERR);

1499

}

1500

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

1501

if(ret == -1){

1502

perror_plus("setenv");

1503

_exit(EX_OSERR);

1504

}

1505

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

1506

if(ret == -1){

1507

perror_plus("setenv");

1508

_exit(EX_OSERR);

1509

}

1510

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

1511

if(ret == -1){

1512

perror_plus("setenv");

1513

_exit(EX_OSERR);

1514

}

1515

char *delaystring;

1516

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

1517

if(ret == -1){

1518

perror_plus("asprintf");

1519

_exit(EX_OSERR);

1520

}

1521

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

1522

if(ret == -1){

1523

free(delaystring);

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1527

1995

free(delaystring);

1528

if(connect_to != NULL){

1529

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

1530

if(ret == -1){

1531

perror_plus("setenv");

1532

_exit(EX_OSERR);

1533

}

1534

}

1535

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

1536

perror_plus("execl");

1537

_exit(EXIT_FAILURE);

1538

}

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;

1539

2064

} else {

1540

int status;

1541

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

1542

perror_plus("waitpid");

1543

free(fullname);

1544

continue;

1545

}

1546

if(WIFEXITED(status)){

1547

if(WEXITSTATUS(status) != 0){

1548

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

1549

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

1550

WEXITSTATUS(status));

1551

free(fullname);

1552

continue;

1553

}

1554

} else if(WIFSIGNALED(status)){

1555

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

1556

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

1557

WTERMSIG(status));

1558

free(fullname);

1559

continue;

1560

} else {

1561

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

1562

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

1563

free(fullname);

1564

continue;

1565

}

1566

}

1567

free(fullname);

1568

if(debug){

1569

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

1570

direntry->d_name);

1571

}

1572

}

1573

close(devnull);

1574

}

1575

return true;

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);

1576

2084

}

1577

2085

2086

__attribute__((nonnull, warn_unused_result))

1578

2087

error_t bring_up_interface(const char *const interface,

1579

2088

const float delay){

1580

int sd = -1;

1581

2089

error_t old_errno = errno;

1582

error_t ret_errno = 0;

1583

int ret, ret_setflags;

2090

int ret;

1584

2091

struct ifreq network;

1585

2092

unsigned int if_index = if_nametoindex(interface);

1586

2093

if(if_index == 0){

1595

2102

}

1596

2103

1597

2104

if(not interface_is_up(interface)){

1598

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

2105

error_t ret_errno = 0, ioctl_errno = 0;

2106

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

1599

2107

ret_errno = errno;

1600

2108

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

1601

2109

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

2110

errno = old_errno;

1602

2111

return ret_errno;

1603

2112

}

1604

network.ifr_flags |= IFF_UP;

2113

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

1605

2114

1606

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1607

if(sd < 0){

2115

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

2116

if(sd == -1){

1608

2117

ret_errno = errno;

1609

2118

perror_plus("socket");

1610

2119

errno = old_errno;

1611

2120

return ret_errno;

1612

2121

}

1613

2122

1614

2123

if(quit_now){

1615

close(sd);

2124

ret = close(sd);

2125

if(ret == -1){

2126

perror_plus("close");

2127

}

1616

2128

errno = old_errno;

1617

2129

return EINTR;

1618

2130

}

1622

2134

interface);

1623

2135

}

1624

2136

1625

/* Raise priviliges */

1626

raise_privileges();

2137

/* Raise privileges */

2138

ret_errno = raise_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to raise privileges");

2142

}

1627

2143

1628

2144

#ifdef __linux__

1629

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1630

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

1631

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

1632

bool restore_loglevel = true;

1633

if(ret_linux == -1){

1634

restore_loglevel = false;

1635

perror_plus("klogctl");

2145

int ret_linux;

2146

bool restore_loglevel = false;

2147

if(ret_errno == 0){

2148

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2149

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

2150

ret_linux = klogctl(8, NULL, 5);

2151

if(ret_linux == -1){

2152

perror_plus("klogctl");

2153

} else {

2154

restore_loglevel = true;

2155

}

1636

2156

}

1637

2157

#endif /* __linux__ */

1638

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

1639

ret_errno = errno;

2158

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

2159

ioctl_errno = errno;

1640

2160

#ifdef __linux__

1641

2161

if(restore_loglevel){

1642

2162

ret_linux = klogctl(7, NULL, 0);

1646

2166

}

1647

2167

#endif /* __linux__ */

1648

2168

1649

/* Lower privileges */

1650

lower_privileges();

2169

/* If raise_privileges() succeeded above */

2170

if(ret_errno == 0){

2171

/* Lower privileges */

2172

ret_errno = lower_privileges();

2173

if(ret_errno != 0){

2174

errno = ret_errno;

2175

perror_plus("Failed to lower privileges");

2176

}

2177

}

1651

2178

1652

2179

/* Close the socket */

1653

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

2180

ret = close(sd);

1654

2181

if(ret == -1){

1655

2182

perror_plus("close");

1656

2183

}

1657

2184

1658

2185

if(ret_setflags == -1){

1659

errno = ret_errno;

2186

errno = ioctl_errno;

1660

2187

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1661

2188

errno = old_errno;

1662

return ret_errno;

2189

return ioctl_errno;

1663

2190

}

1664

2191

} else if(debug){

1665

2192

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

1683

2210

return 0;

1684

2211

}

1685

2212

2213

__attribute__((nonnull, warn_unused_result))

1686

2214

error_t take_down_interface(const char *const interface){

1687

int sd = -1;

1688

2215

error_t old_errno = errno;

1689

error_t ret_errno = 0;

1690

int ret, ret_setflags;

1691

2216

struct ifreq network;

1692

2217

unsigned int if_index = if_nametoindex(interface);

1693

2218

if(if_index == 0){

1696

2221

return ENXIO;

1697

2222

}

1698

2223

if(interface_is_up(interface)){

2224

error_t ret_errno = 0, ioctl_errno = 0;

1699

2225

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

1700

2226

ret_errno = errno;

1701

2227

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

1702

2228

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

2229

errno = old_errno;

1703

2230

return ret_errno;

1704

2231

}

1705

2232

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

1706

2233

1707

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1708

if(sd < 0){

2234

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

2235

if(sd == -1){

1709

2236

ret_errno = errno;

1710

2237

perror_plus("socket");

1711

2238

errno = old_errno;

1717

2244

interface);

1718

2245

}

1719

2246

1720

/* Raise priviliges */

1721

raise_privileges();

1722

1723

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

1724

ret_errno = errno;

1725

1726

/* Lower privileges */

1727

lower_privileges();

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

}

1728

2266

1729

2267

/* Close the socket */

1730

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

2268

int ret = close(sd);

1731

2269

if(ret == -1){

1732

2270

perror_plus("close");

1733

2271

}

1734

2272

1735

2273

if(ret_setflags == -1){

1736

errno = ret_errno;

2274

errno = ioctl_errno;

1737

2275

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1738

2276

errno = old_errno;

1739

return ret_errno;

2277

return ioctl_errno;

1740

2278

}

1741

2279

} else if(debug){

1742

2280

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

1748

2286

}

1749

2287

1750

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", .current_server = NULL,

2292

.interfaces = NULL, .interfaces_size = 0 };

1751

2293

AvahiSServiceBrowser *sb = NULL;

1752

2294

error_t ret_errno;

1753

2295

int ret;

1754

2296

intmax_t tmpmax;

1755

2297

char *tmp;

1756

2298

int exitcode = EXIT_SUCCESS;

1757

char *interfaces = NULL;

1758

size_t interfaces_size = 0;

1759

2299

char *interfaces_to_take_down = NULL;

1760

2300

size_t interfaces_to_take_down_size = 0;

1761

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

1762

bool tempdir_created = false;

2301

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

2302

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

2303

char *tempdir = NULL;

1763

2304

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1764

2305

const char *seckey = PATHDIR "/" SECKEY;

1765

2306

const char *pubkey = PATHDIR "/" PUBKEY;

2307

const char *dh_params_file = NULL;

1766

2308

char *interfaces_hooks = NULL;

1767

size_t interfaces_hooks_size = 0;

1768

2309

1769

2310

bool gnutls_initialized = false;

1770

2311

bool gpgme_initialized = false;

1822

2363

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

1823

2364

" Diffie-Hellman key exchange",

1824

2365

.group = 2 },

2366

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

2367

.arg = "FILE",

2368

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

2369

" for the Diffie-Hellman key exchange",

2370

.group = 2 },

1825

2371

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

1826

2372

.arg = "STRING",

1827

2373

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

1861

2407

connect_to = arg;

1862

2408

break;

1863

2409

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

1864

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

1865

(int)',');

2410

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

2411

arg, (int)',');

1866

2412

if(ret_errno != 0){

1867

2413

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

1868

2414

}

1882

2428

}

1883

2429

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

1884

2430

break;

2431

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

2432

dh_params_file = arg;

2433

break;

1885

2434

case 130: /* --priority */

1886

2435

mc.priority = arg;

1887

2436

break;

1943

2492

goto end;

1944

2493

}

1945

2494

}

1946

2495

1947

2496

{

1948

2497

/* Work around Debian bug #633582:

1949

2498

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

1950

2499

1951

/* Re-raise priviliges */

1952

if(raise_privileges() == 0){

2500

/* Re-raise privileges */

2501

ret_errno = raise_privileges();

2502

if(ret_errno != 0){

2503

errno = ret_errno;

2504

perror_plus("Failed to raise privileges");

2505

} else {

1953

2506

struct stat st;

1954

2507

1955

2508

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

1969

2522

}

1970

2523

}

1971

2524

}

1972

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

close(seckey_fd);

1973

2526

}

1974

2527

}

1975

2528

1976

2529

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

1977

2530

int pubkey_fd = open(pubkey, O_RDONLY);

1978

2531

if(pubkey_fd == -1){

1990

2543

}

1991

2544

}

1992

2545

}

1993

TEMP_FAILURE_RETRY(close(pubkey_fd));

1994

}

1995

}

1996

2546

close(pubkey_fd);

2547

}

2548

}

2549

2550

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

2551

int dhparams_fd = open(dh_params_file, O_RDONLY);

2552

if(dhparams_fd == -1){

2553

perror_plus("open");

2554

} else {

2555

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

2556

if(ret == -1){

2557

perror_plus("fstat");

2558

} else {

2559

if(S_ISREG(st.st_mode)

2560

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

2561

ret = fchown(dhparams_fd, uid, gid);

2562

if(ret == -1){

2563

perror_plus("fchown");

2564

}

2565

}

2566

}

2567

close(dhparams_fd);

2568

}

2569

}

2570

1997

2571

/* Lower privileges */

1998

errno = 0;

1999

ret = seteuid(uid);

2000

if(ret == -1){

2001

perror_plus("seteuid");

2572

ret_errno = lower_privileges();

2573

if(ret_errno != 0){

2574

errno = ret_errno;

2575

perror_plus("Failed to lower privileges");

2002

2576

}

2003

2577

}

2004

2578

}

2005

2579

2006

/* Remove empty interface names */

2580

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

2007

2581

{

2008

2582

char *interface = NULL;

2009

while((interface = argz_next(interfaces, interfaces_size,

2583

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

2010

2584

interface))){

2011

if(if_nametoindex(interface) == 0){

2012

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

2585

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

2586

and if_nametoindex(interface) == 0){

2587

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

2013

2588

fprintf_plus(stderr, "Not using nonexisting interface"

2014

2589

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

2015

2590

}

2016

argz_delete(&interfaces, &interfaces_size, interface);

2591

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

2017

2592

interface = NULL;

2018

2593

}

2019

2594

}

2021

2596

2022

2597

/* Run network hooks */

2023

2598

{

2024

2025

if(interfaces != NULL){

2026

interfaces_hooks = malloc(interfaces_size);

2599

if(mc.interfaces != NULL){

2600

interfaces_hooks = malloc(mc.interfaces_size);

2027

2601

if(interfaces_hooks == NULL){

2028

2602

perror_plus("malloc");

2029

2603

goto end;

2030

2604

}

2031

memcpy(interfaces_hooks, interfaces, interfaces_size);

2032

interfaces_hooks_size = interfaces_size;

2033

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2034

(int)',');

2035

}

2036

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

2037

interfaces_hooks : "", delay)){

2038

goto end;

2039

}

2605

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

2606

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

2607

}

2608

run_network_hooks("start", interfaces_hooks != NULL ?

2609

interfaces_hooks : "", delay);

2040

2610

}

2041

2611

2042

2612

if(not debug){

2047

2617

from the signal handler */

2048

2618

/* Initialize the pseudo-RNG for Avahi */

2049

2619

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

2050

mc.simple_poll = avahi_simple_poll_new();

2051

if(mc.simple_poll == NULL){

2620

simple_poll = avahi_simple_poll_new();

2621

if(simple_poll == NULL){

2052

2622

fprintf_plus(stderr,

2053

2623

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

2054

2624

exitcode = EX_UNAVAILABLE;

2119

2689

}

2120

2690

2121

2691

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

2122

if(interfaces == NULL){

2123

struct dirent **direntries;

2692

if(mc.interfaces == NULL){

2693

struct dirent **direntries = NULL;

2124

2694

/* Look for any good interfaces */

2125

2695

ret = scandir(sys_class_net, &direntries, good_interface,

2126

2696

alphasort);

2127

2697

if(ret >= 1){

2128

2698

/* Add all found interfaces to interfaces list */

2129

2699

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

2130

ret_errno = argz_add(&interfaces, &interfaces_size,

2700

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

2131

2701

direntries[i]->d_name);

2132

2702

if(ret_errno != 0){

2703

errno = ret_errno;

2133

2704

perror_plus("argz_add");

2705

free(direntries[i]);

2134

2706

continue;

2135

2707

}

2136

2708

if(debug){

2137

2709

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

2138

2710

direntries[i]->d_name);

2139

2711

}

2712

free(direntries[i]);

2140

2713

}

2141

2714

free(direntries);

2142

2715

} else {

2143

free(direntries);

2716

if(ret == 0){

2717

free(direntries);

2718

}

2144

2719

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

2145

2720

exitcode = EXIT_FAILURE;

2146

2721

goto end;

2147

2722

}

2148

2723

}

2149

2724

2150

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

2151

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

2152

if(debug){

2153

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

2154

interfaces);

2155

}

2156

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2157

}

2158

2159

/* Bring up interfaces which are down */

2160

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

2161

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

2725

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

2726

{

2162

2727

char *interface = NULL;

2163

while((interface = argz_next(interfaces, interfaces_size,

2728

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

2164

2729

interface))){

2730

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

2731

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

2732

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

2733

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

2734

interface);

2735

interface = NULL;

2736

while((interface = argz_next(mc.interfaces,

2737

mc.interfaces_size, interface))){

2738

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

2739

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

2740

interface);

2741

interface = NULL;

2742

}

2743

}

2744

break;

2745

}

2165

2746

bool interface_was_up = interface_is_up(interface);

2166

ret = bring_up_interface(interface, delay);

2747

errno = bring_up_interface(interface, delay);

2167

2748

if(not interface_was_up){

2168

if(ret != 0){

2169

errno = ret;

2170

perror_plus("Failed to bring up interface");

2749

if(errno != 0){

2750

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

2751

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

2171

2752

} else {

2172

ret_errno = argz_add(&interfaces_to_take_down,

2173

&interfaces_to_take_down_size,

2174

interface);

2753

errno = argz_add(&interfaces_to_take_down,

2754

&interfaces_to_take_down_size,

2755

interface);

2756

if(errno != 0){

2757

perror_plus("argz_add");

2758

}

2175

2759

}

2176

2760

}

2177

2761

}

2178

free(interfaces);

2179

interfaces = NULL;

2180

interfaces_size = 0;

2181

2762

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

2182

2763

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

2183

2764

}

2184

2765

}

2185

2766

2767

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

2768

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

2769

if(debug){

2770

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

2771

mc.interfaces);

2772

}

2773

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

2774

}

2775

2186

2776

if(quit_now){

2187

2777

goto end;

2188

2778

}

2189

2779

2190

ret = init_gnutls_global(pubkey, seckey);

2780

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

2191

2781

if(ret == -1){

2192

2782

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

2193

2783

exitcode = EX_UNAVAILABLE;

2200

2790

goto end;

2201

2791

}

2202

2792

2203

if(mkdtemp(tempdir) == NULL){

2793

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

2794

tempdir = mkdtemp(run_tempdir);

2795

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

2796

if(debug){

2797

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

2798

run_tempdir, old_tempdir);

2799

}

2800

tempdir = mkdtemp(old_tempdir);

2801

}

2802

if(tempdir == NULL){

2204

2803

perror_plus("mkdtemp");

2205

2804

goto end;

2206

2805

}

2207

tempdir_created = true;

2208

2806

2209

2807

if(quit_now){

2210

2808

goto end;

2211

2809

}

2212

2810

2213

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

2811

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

2214

2812

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

2215

2813

exitcode = EX_UNAVAILABLE;

2216

2814

goto end;

2246

2844

exitcode = EX_USAGE;

2247

2845

goto end;

2248

2846

}

2249

2847

2250

2848

if(quit_now){

2251

2849

goto end;

2252

2850

}

2273

2871

}

2274

2872

2275

2873

while(not quit_now){

2276

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

2874

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

2875

&mc);

2277

2876

if(quit_now or ret == 0){

2278

2877

break;

2279

2878

}

2281

2880

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

2282

2881

(int)retry_interval);

2283

2882

}

2284

sleep((int)retry_interval);

2883

sleep((unsigned int)retry_interval);

2285

2884

}

2286

2885

2287

if (not quit_now){

2886

if(not quit_now){

2288

2887

exitcode = EXIT_SUCCESS;

2289

2888

}

2290

2889

2305

2904

config.publish_domain = 0;

2306

2905

2307

2906

/* Allocate a new server */

2308

mc.server = avahi_server_new(avahi_simple_poll_get

2309

(mc.simple_poll), &config, NULL,

2310

NULL, &ret_errno);

2907

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2908

&config, NULL, NULL, &ret_errno);

2311

2909

2312

2910

/* Free the Avahi configuration data */

2313

2911

avahi_server_config_free(&config);

2328

2926

/* Create the Avahi service browser */

2329

2927

sb = avahi_s_service_browser_new(mc.server, if_index,

2330

2928

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2331

NULL, 0, browse_callback, NULL);

2929

NULL, 0, browse_callback,

2930

(void *)&mc);

2332

2931

if(sb == NULL){

2333

2932

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

2334

2933

avahi_strerror(avahi_server_errno(mc.server)));

2345

2944

if(debug){

2346

2945

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

2347

2946

}

2348

2349

ret = avahi_loop_with_timeout(mc.simple_poll,

2350

(int)(retry_interval * 1000));

2947

2948

ret = avahi_loop_with_timeout(simple_poll,

2949

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

2351

2950

if(debug){

2352

2951

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

2353

2952

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

2360

2959

}

2361

2960

2362

2961

/* Cleanup things */

2962

free(mc.interfaces);

2963

2363

2964

if(sb != NULL)

2364

2965

avahi_s_service_browser_free(sb);

2365

2966

2366

2967

if(mc.server != NULL)

2367

2968

avahi_server_free(mc.server);

2368

2969

2369

if(mc.simple_poll != NULL)

2370

avahi_simple_poll_free(mc.simple_poll);

2970

if(simple_poll != NULL)

2971

avahi_simple_poll_free(simple_poll);

2371

2972

2372

2973

if(gnutls_initialized){

2373

2974

gnutls_certificate_free_credentials(mc.cred);

2385

2986

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

2386

2987

while(mc.current_server != NULL){

2387

2988

server *next = mc.current_server->next;

2989

#ifdef __GNUC__

2990

#pragma GCC diagnostic push

2991

#pragma GCC diagnostic ignored "-Wcast-qual"

2992

#endif

2993

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

2994

#ifdef __GNUC__

2995

#pragma GCC diagnostic pop

2996

#endif

2388

2997

free(mc.current_server);

2389

2998

mc.current_server = next;

2390

2999

}

2391

3000

}

2392

3001

2393

/* Re-raise priviliges */

3002

/* Re-raise privileges */

2394

3003

{

2395

raise_privileges();

2396

2397

/* Run network hooks */

2398

run_network_hooks("stop", interfaces_hooks != NULL ?

2399

interfaces_hooks : "", delay);

2400

2401

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

2402

{

2403

char *interface = NULL;

2404

while((interface=argz_next(interfaces_to_take_down,

2405

interfaces_to_take_down_size,

2406

interface))){

2407

ret_errno = take_down_interface(interface);

2408

if(ret_errno != 0){

2409

errno = ret_errno;

2410

perror_plus("Failed to take down interface");

2411

}

2412

}

2413

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

2414

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

2415

" down\n");

2416

}

2417

}

2418

2419

lower_privileges_permanently();

3004

ret_errno = raise_privileges();

3005

if(ret_errno != 0){

3006

errno = ret_errno;

3007

perror_plus("Failed to raise privileges");

3008

} else {

3009

3010

/* Run network hooks */

3011

run_network_hooks("stop", interfaces_hooks != NULL ?

3012

interfaces_hooks : "", delay);

3013

3014

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

3015

{

3016

char *interface = NULL;

3017

while((interface=argz_next(interfaces_to_take_down,

3018

interfaces_to_take_down_size,

3019

interface))){

3020

ret_errno = take_down_interface(interface);

3021

if(ret_errno != 0){

3022

errno = ret_errno;

3023

perror_plus("Failed to take down interface");

3024

}

3025

}

3026

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

3027

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

3028

" down\n");

3029

}

3030

}

3031

}

3032

3033

ret_errno = lower_privileges_permanently();

3034

if(ret_errno != 0){

3035

errno = ret_errno;

3036

perror_plus("Failed to lower privileges permanently");

3037

}

2420

3038

}

2421

3039

2422

3040

free(interfaces_to_take_down);

2423

3041

free(interfaces_hooks);

2424

3042

2425

3043

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

2426

if(tempdir_created){

3044

if(tempdir != NULL){

2427

3045

struct dirent **direntries = NULL;

2428

struct dirent *direntry = NULL;

2429

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

2430

alphasort);

2431

if (numentries > 0){

2432

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

2433

direntry = direntries[i];

2434

char *fullname = NULL;

2435

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

2436

direntry->d_name);

2437

if(ret < 0){

2438

perror_plus("asprintf");

2439

continue;

2440

}

2441

ret = remove(fullname);

2442

if(ret == -1){

2443

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

2444

strerror(errno));

2445

}

2446

free(fullname);

3046

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY

3047

| O_NOFOLLOW

3048

| O_DIRECTORY

3049

| O_PATH));

3050

if(tempdir_fd == -1){

3051

perror_plus("open");

3052

} else {

3053

#ifdef __GLIBC__

3054

#if __GLIBC_PREREQ(2, 15)

3055

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

3056

notdotentries, alphasort);

3057

#else /* not __GLIBC_PREREQ(2, 15) */

3058

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

3059

alphasort);

3060

#endif /* not __GLIBC_PREREQ(2, 15) */

3061

#else /* not __GLIBC__ */

3062

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

3063

alphasort);

3064

#endif /* not __GLIBC__ */

3065

if(numentries >= 0){

3066

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

3067

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

3068

if(ret == -1){

3069

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

3070

" \"%s\", 0): %s\n", tempdir,

3071

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

3072

}

3073

free(direntries[i]);

3074

}

3075

3076

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

3077

free(direntries);

3078

if(numentries == -1){

3079

perror_plus("scandir");

3080

}

3081

ret = rmdir(tempdir);

3082

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

3083

perror_plus("rmdir");

3084

}

2447

3085

}

2448

}

2449

2450

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

2451

free(direntries);

2452

if (numentries == -1){

2453

perror_plus("scandir");

2454

}

2455

ret = rmdir(tempdir);

2456

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

2457

perror_plus("rmdir");

3086

close(tempdir_fd);

2458

3087

}

2459

3088

}

2460

3089