/mandos/release : revision 237.7.147

9

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

10

*

11

* Everything else is

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13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

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() */

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stdout, ferror(), remove() */

44

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

45

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

46

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

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strtof(), abort() */

48

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

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

50

asprintf(), strcpy() */

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

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

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#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 */

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

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inet_pton(), connect(),

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getnameinfo() */

60

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

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inet_pton(), connect() */

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

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60

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

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61

*/

63

62

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

73

72

*/

74

73

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

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74

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

76

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

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unlinkat() */

78

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

75

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

76

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

79

77

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

80

78

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

81

79

argp_state, struct argp,

93

91

argz_delete(), argz_append(),

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92

argz_stringify(), argz_add(),

95

93

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

98

94

99

95

#ifdef __linux__

100

96

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

142

138

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

143

139

char *connect_to = NULL;

144

140

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

141

uid_t uid = 65534;

147

142

gid_t gid = 65534;

148

143

159

154

160

155

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

161

156

typedef struct {

157

AvahiSimplePoll *simple_poll;

162

158

AvahiServer *server;

163

159

gnutls_certificate_credentials_t cred;

164

160

unsigned int dh_bits;

166

162

const char *priority;

167

163

gpgme_ctx_t ctx;

168

164

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

171

165

} mandos_context;

172

166

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

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 };

175

172

176

173

sig_atomic_t quit_now = 0;

177

174

int signal_received = 0;

185

182

perror(print_text);

186

183

}

187

184

188

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

185

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

189

186

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

190

187

va_list ap;

191

188

va_start (ap, format);

192

189

193

190

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

194

191

program_invocation_short_name));

195

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

192

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

196

193

}

197

194

198

195

/*

200

197

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

201

198

* "buffer_length" is how much is already used.

202

199

*/

203

__attribute__((nonnull, warn_unused_result))

204

200

size_t incbuffer(char **buffer, size_t buffer_length,

205

201

size_t buffer_capacity){

206

202

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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;

203

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

204

if(buffer == NULL){

213

205

return 0;

214

206

}

215

*buffer = new_buf;

216

207

buffer_capacity += BUFFER_SIZE;

217

208

}

218

209

return buffer_capacity;

219

210

}

220

211

221

212

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

222

__attribute__((nonnull, warn_unused_result))

223

213

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

224

int af, server **current_server){

214

int af){

225

215

int ret;

226

216

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

227

217

if(new_server == NULL){

234

224

.af = af };

235

225

if(new_server->ip == NULL){

236

226

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);

252

227

return false;

253

228

}

254

229

/* Special case of first server */

255

if(*current_server == NULL){

230

if (mc.current_server == NULL){

256

231

new_server->next = new_server;

257

232

new_server->prev = new_server;

258

*current_server = new_server;

233

mc.current_server = new_server;

234

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

259

235

} else {

260

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

261

new_server->next = *current_server;

262

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

236

new_server->next = mc.current_server;

237

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

263

238

new_server->prev->next = new_server;

264

(*current_server)->prev = 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;

265

245

}

266

246

return true;

267

247

}

269

249

/*

270

250

* Initialize GPGME.

271

251

*/

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){

252

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

253

const char *tempdir){

277

254

gpgme_error_t rc;

278

255

gpgme_engine_info_t engine_info;

279

256

257

280

258

/*

281

259

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

282

260

*/

283

bool import_key(const char * const filename){

261

bool import_key(const char *filename){

284

262

int ret;

285

263

int fd;

286

264

gpgme_data_t pgp_data;

298

276

return false;

299

277

}

300

278

301

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

279

rc = gpgme_op_import(mc.ctx, pgp_data);

302

280

if(rc != GPG_ERR_NO_ERROR){

303

281

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

304

282

gpgme_strsource(rc), gpgme_strerror(rc));

305

283

return false;

306

284

}

307

285

308

ret = close(fd);

286

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

309

287

if(ret == -1){

310

288

perror_plus("close");

311

289

}

348

326

}

349

327

350

328

/* Create new GPGME "context" */

351

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

329

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

352

330

if(rc != GPG_ERR_NO_ERROR){

353

331

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

354

332

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

367

345

* Decrypt OpenPGP data.

368

346

* Returns -1 on error

369

347

*/

370

__attribute__((nonnull, warn_unused_result))

371

348

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

349

size_t crypto_size,

373

char **plaintext,

374

mandos_context *mc){

350

char **plaintext){

375

351

gpgme_data_t dh_crypto, dh_plain;

376

352

gpgme_error_t rc;

377

353

ssize_t ret;

403

379

404

380

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

405

381

data buffer */

406

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

382

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

407

383

if(rc != GPG_ERR_NO_ERROR){

408

384

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

409

385

gpgme_strsource(rc), gpgme_strerror(rc));

410

386

plaintext_length = -1;

411

387

if(debug){

412

388

gpgme_decrypt_result_t result;

413

result = gpgme_op_decrypt_result(mc->ctx);

389

result = gpgme_op_decrypt_result(mc.ctx);

414

390

if(result == NULL){

415

391

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

416

392

} else {

493

469

return plaintext_length;

494

470

}

495

471

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){

472

static const char * safer_gnutls_strerror(int value){

505

473

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

474

if(ret == NULL)

475

ret = "(unknown)";

476

return ret;

507

477

}

508

478

509

479

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

480

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

512

481

const char* string){

513

482

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

514

483

}

515

484

516

__attribute__((nonnull, warn_unused_result))

517

485

static int init_gnutls_global(const char *pubkeyfilename,

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

486

const char *seckeyfilename){

521

487

int ret;

522

unsigned int uret;

523

488

524

489

if(debug){

525

490

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

541

506

}

542

507

543

508

/* OpenPGP credentials */

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

545

510

if(ret != GNUTLS_E_SUCCESS){

546

511

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

547

512

safer_gnutls_strerror(ret));

557

522

}

558

523

559

524

ret = gnutls_certificate_set_openpgp_key_file

560

(mc->cred, pubkeyfilename, seckeyfilename,

525

(mc.cred, pubkeyfilename, seckeyfilename,

561

526

GNUTLS_OPENPGP_FMT_BASE64);

562

527

if(ret != GNUTLS_E_SUCCESS){

563

528

fprintf_plus(stderr,

569

534

}

570

535

571

536

/* GnuTLS server initialization */

572

ret = gnutls_dh_params_init(&mc->dh_params);

537

ret = gnutls_dh_params_init(&mc.dh_params);

573

538

if(ret != GNUTLS_E_SUCCESS){

574

539

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

575

540

" initialization: %s\n",

576

541

safer_gnutls_strerror(ret));

577

542

goto globalfail;

578

543

}

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);

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);

752

552

753

553

return 0;

754

554

755

555

globalfail:

756

556

757

gnutls_certificate_free_credentials(mc->cred);

557

gnutls_certificate_free_credentials(mc.cred);

758

558

gnutls_global_deinit();

759

gnutls_dh_params_deinit(mc->dh_params);

559

gnutls_dh_params_deinit(mc.dh_params);

760

560

return -1;

761

561

}

762

562

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

563

static int init_gnutls_session(gnutls_session_t *session){

766

564

int ret;

767

565

/* GnuTLS session creation */

768

566

do {

780

578

{

781

579

const char *err;

782

580

do {

783

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

581

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

784

582

if(quit_now){

785

583

gnutls_deinit(*session);

786

584

return -1;

797

595

798

596

do {

799

597

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

800

mc->cred);

598

mc.cred);

801

599

if(quit_now){

802

600

gnutls_deinit(*session);

803

601

return -1;

813

611

/* ignore client certificate if any. */

814

612

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

613

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

615

816

616

return 0;

817

617

}

818

618

820

620

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

821

621

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

822

622

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

close(helperdir_fd);

958

_exit(EX_UNAVAILABLE);

959

}

960

close(helperdir_fd);

961

#ifdef __GNUC__

962

#pragma GCC diagnostic push

963

#pragma GCC diagnostic ignored "-Wcast-qual"

964

#endif

965

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

966

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

967

interface, debug ? debug_flag : NULL, NULL },

968

environ) == -1){

969

#ifdef __GNUC__

970

#pragma GCC diagnostic pop

971

#endif

972

perror_plus("fexecve");

973

_exit(EXIT_FAILURE);

974

}

975

}

976

if(pid == -1){

977

perror_plus("fork");

978

return false;

979

}

980

int status;

981

pid_t pret = -1;

982

errno = 0;

983

do {

984

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

985

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

986

int errno_raising = 0;

987

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

988

errno_raising = errno;

989

perror_plus("Failed to raise privileges in order to"

990

" kill helper program");

991

}

992

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

993

perror_plus("kill");

994

}

995

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

996

perror_plus("Failed to lower privileges after killing"

997

" helper program");

998

}

999

return false;

1000

}

1001

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

1002

if(pret == -1){

1003

perror_plus("waitpid");

1004

return false;

1005

}

1006

if(WIFEXITED(status)){

1007

if(WEXITSTATUS(status) != 0){

1008

fprintf_plus(stderr, "Error: iprouteadddel exited"

1009

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

1010

return false;

1011

}

1012

return true;

1013

}

1014

if(WIFSIGNALED(status)){

1015

fprintf_plus(stderr, "Error: iprouteadddel died by"

1016

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

1017

return false;

1018

}

1019

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

1020

return false;

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool add_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(true, address, if_index);

1030

}

1031

1032

__attribute__((nonnull, warn_unused_result))

1033

static bool delete_local_route(const char *address,

1034

AvahiIfIndex if_index){

1035

if(debug){

1036

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

1037

}

1038

return add_delete_local_route(false, address, if_index);

1039

}

1040

1041

623

/* Called when a Mandos server is found */

1042

__attribute__((nonnull, warn_unused_result))

1043

624

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

1044

625

AvahiIfIndex if_index,

1045

int af, mandos_context *mc){

626

int af){

1046

627

int ret, tcp_sd = -1;

1047

628

ssize_t sret;

1048

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1049

633

char *buffer = NULL;

1050

634

char *decrypted_buffer = NULL;

1051

635

size_t buffer_length = 0;

1054

638

int retval = -1;

1055

639

gnutls_session_t session;

1056

640

int pf; /* Protocol family */

1057

bool route_added = false;

1058

641

1059

642

errno = 0;

1060

643

1076

659

return -1;

1077

660

}

1078

661

1079

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

1080

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

1081

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

1082

bool match = false;

1083

{

1084

char *interface = NULL;

1085

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

1086

interface))){

1087

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

1088

match = true;

1089

break;

1090

}

1091

}

1092

}

1093

if(not match){

1094

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

1095

connect to the server */

1096

if(debug){

1097

char interface[IF_NAMESIZE];

1098

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

1099

perror_plus("if_indextoname");

1100

} else {

1101

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

1102

" \"%s\"\n",

1103

if_indextoname((unsigned int)if_index,

1104

interface));

1105

}

1106

}

1107

return -1;

1108

}

1109

}

1110

1111

ret = init_gnutls_session(&session, mc);

662

ret = init_gnutls_session(&session);

1112

663

if(ret != 0){

1113

664

return -1;

1114

665

}

1118

669

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

1119

670

}

1120

671

1121

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

672

tcp_sd = socket(pf, SOCK_STREAM, 0);

1122

673

if(tcp_sd < 0){

1123

674

int e = errno;

1124

675

perror_plus("socket");

1131

682

goto mandos_end;

1132

683

}

1133

684

685

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

1134

686

if(af == AF_INET6){

1135

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

1136

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

1137

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

687

to.in6.sin6_family = (sa_family_t)af;

688

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

1138

689

} else { /* IPv4 */

1139

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

1140

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

1141

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

690

to.in.sin_family = (sa_family_t)af;

691

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

1142

692

}

1143

693

if(ret < 0 ){

1144

694

int e = errno;

1153

703

goto mandos_end;

1154

704

}

1155

705

if(af == AF_INET6){

1156

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

1157

if(IN6_IS_ADDR_LINKLOCAL

1158

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

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*/

1159

710

if(if_index == AVAHI_IF_UNSPEC){

1160

711

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

1161

712

" incomplete without a network interface\n");

1163

714

goto mandos_end;

1164

715

}

1165

716

/* Set the network interface number as scope */

1166

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

717

to.in6.sin6_scope_id = (uint32_t)if_index;

1167

718

}

1168

719

} else {

1169

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

720

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

721

-Wconversion and

722

-Wunreachable-code */

1170

723

}

1171

724

1172

725

if(quit_now){

1189

742

}

1190

743

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1191

744

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1192

if(af == AF_INET6){

1193

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

1194

sizeof(struct sockaddr_in6),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

} else {

1198

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

1199

sizeof(struct sockaddr_in),

1200

addrstr, sizeof(addrstr), NULL, 0,

1201

NI_NUMERICHOST);

1202

}

1203

if(ret == EAI_SYSTEM){

1204

perror_plus("getnameinfo");

1205

} else if(ret != 0) {

1206

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

1207

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

1208

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

1209

}

1210

}

1211

1212

if(quit_now){

1213

errno = EINTR;

1214

goto mandos_end;

1215

}

1216

1217

while(true){

1218

if(af == AF_INET6){

1219

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

1220

sizeof(struct sockaddr_in6));

1221

} else {

1222

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

1223

sizeof(struct sockaddr_in));

1224

}

1225

if(ret < 0){

1226

if(errno == ENETUNREACH

1227

and if_index != AVAHI_IF_UNSPEC

1228

and connect_to == NULL

1229

and not route_added and

1230

((af == AF_INET6 and not

1231

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1232

&to)->sin6_addr)))

1233

or (af == AF_INET and

1234

/* Not a a IPv4LL address */

1235

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

1236

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

1237

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

1238

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

1239

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

1240

connect to a Mandos server announced by Avahi on a server

1241

host with a global address. Work around this by retrying

1242

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

1243

1244

Avahi bug reference:

1245

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

1246

https://bugs.debian.org/587961

1247

*/

1248

if(debug){

1249

fprintf_plus(stderr, "Mandos server unreachable, trying"

1250

" direct route\n");

1251

}

1252

int e = errno;

1253

route_added = add_local_route(ip, if_index);

1254

if(route_added){

1255

continue;

1256

}

1257

errno = e;

1258

}

1259

if(errno != ECONNREFUSED or debug){

1260

int e = errno;

1261

perror_plus("connect");

1262

errno = e;

1263

}

1264

goto mandos_end;

1265

}

1266

1267

if(quit_now){

1268

errno = EINTR;

1269

goto mandos_end;

1270

}

1271

break;

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;

1272

784

}

1273

785

1274

786

const char *out = mandos_protocol_version;

1425

937

if(buffer_length > 0){

1426

938

ssize_t decrypted_buffer_size;

1427

939

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1428

&decrypted_buffer, mc);

940

&decrypted_buffer);

1429

941

if(decrypted_buffer_size >= 0){

1430

942

1431

943

written = 0;

1457

969

1458

970

mandos_end:

1459

971

{

1460

if(route_added){

1461

if(not delete_local_route(ip, if_index)){

1462

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

1463

" interface %d", ip, if_index);

1464

}

1465

}

1466

972

int e = errno;

1467

973

free(decrypted_buffer);

1468

974

free(buffer);

1469

975

if(tcp_sd >= 0){

1470

ret = close(tcp_sd);

976

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

1471

977

}

1472

978

if(ret == -1){

1473

979

if(e == 0){

1485

991

return retval;

1486

992

}

1487

993

1488

__attribute__((nonnull))

1489

994

static void resolve_callback(AvahiSServiceResolver *r,

1490

995

AvahiIfIndex interface,

1491

996

AvahiProtocol proto,

1499

1004

AVAHI_GCC_UNUSED AvahiStringList *txt,

1500

1005

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1501

1006

flags,

1502

void *mc){

1007

AVAHI_GCC_UNUSED void* userdata){

1503

1008

if(r == NULL){

1504

1009

return;

1505

1010

}

1508

1013

timed out */

1509

1014

1510

1015

if(quit_now){

1511

avahi_s_service_resolver_free(r);

1512

1016

return;

1513

1017

}

1514

1018

1518

1022

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

1519

1023

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

1520

1024

domain,

1521

avahi_strerror(avahi_server_errno

1522

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

1025

avahi_strerror(avahi_server_errno(mc.server)));

1523

1026

break;

1524

1027

1525

1028

case AVAHI_RESOLVER_FOUND:

1533

1036

}

1534

1037

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

1535

1038

interface,

1536

avahi_proto_to_af(proto),

1537

mc);

1039

avahi_proto_to_af(proto));

1538

1040

if(ret == 0){

1539

avahi_simple_poll_quit(simple_poll);

1041

avahi_simple_poll_quit(mc.simple_poll);

1540

1042

} else {

1541

1043

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

1542

avahi_proto_to_af(proto),

1543

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

1044

avahi_proto_to_af(proto))){

1544

1045

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

1545

1046

" list\n", name);

1546

1047

}

1559

1060

const char *domain,

1560

1061

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1561

1062

flags,

1562

void *mc){

1063

AVAHI_GCC_UNUSED void* userdata){

1563

1064

if(b == NULL){

1564

1065

return;

1565

1066

}

1576

1077

case AVAHI_BROWSER_FAILURE:

1577

1078

1578

1079

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

1579

avahi_strerror(avahi_server_errno

1580

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

1581

avahi_simple_poll_quit(simple_poll);

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1582

1082

return;

1583

1083

1584

1084

case AVAHI_BROWSER_NEW:

1587

1087

the callback function is called the Avahi server will free the

1588

1088

resolver for us. */

1589

1089

1590

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

1591

interface, protocol, name, type,

1592

domain, protocol, 0,

1593

resolve_callback, mc) == NULL)

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1594

1093

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

1595

1094

" %s\n", name,

1596

avahi_strerror(avahi_server_errno

1597

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

1095

avahi_strerror(avahi_server_errno(mc.server)));

1598

1096

break;

1599

1097

1600

1098

case AVAHI_BROWSER_REMOVE:

1619

1117

signal_received = sig;

1620

1118

int old_errno = errno;

1621

1119

/* set main loop to exit */

1622

if(simple_poll != NULL){

1623

avahi_simple_poll_quit(simple_poll);

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1624

1122

}

1625

1123

errno = old_errno;

1626

1124

}

1627

1125

1628

__attribute__((nonnull, warn_unused_result))

1629

1126

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

1630

1127

int ret;

1631

1128

error_t ret_errno;

1650

1147

return true;

1651

1148

}

1652

1149

1653

__attribute__((nonnull, warn_unused_result))

1654

1150

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

1655

1151

1656

1152

/* Reject the loopback device */

1698

1194

* corresponds to an acceptable network device.

1699

1195

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

1700

1196

*/

1701

__attribute__((nonnull, warn_unused_result))

1702

1197

int good_interface(const struct dirent *if_entry){

1703

1198

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

1704

1199

return 0;

1722

1217

/*

1723

1218

* This function determines if a network interface is up.

1724

1219

*/

1725

__attribute__((nonnull, warn_unused_result))

1726

1220

bool interface_is_up(const char *interface){

1727

1221

struct ifreq ifr;

1728

1222

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

1739

1233

/*

1740

1234

* This function determines if a network interface is running

1741

1235

*/

1742

__attribute__((nonnull, warn_unused_result))

1743

1236

bool interface_is_running(const char *interface){

1744

1237

struct ifreq ifr;

1745

1238

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

1753

1246

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

1754

1247

}

1755

1248

1756

__attribute__((nonnull, pure, warn_unused_result))

1757

1249

int notdotentries(const struct dirent *direntry){

1758

1250

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

1759

1251

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

1766

1258

}

1767

1259

1768

1260

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

1769

__attribute__((nonnull, warn_unused_result))

1770

1261

int runnable_hook(const struct dirent *direntry){

1771

1262

int ret;

1772

1263

size_t sret;

1780

1271

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

1781

1272

"abcdefghijklmnopqrstuvwxyz"

1782

1273

"0123456789"

1783

"_.-");

1274

"_-");

1784

1275

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

1785

1276

/* Contains non-allowed characters */

1786

1277

if(debug){

1790

1281

return 0;

1791

1282

}

1792

1283

1793

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

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);

1794

1292

if(ret == -1){

1795

1293

if(debug){

1796

1294

perror_plus("Could not stat hook");

1820

1318

return 1;

1821

1319

}

1822

1320

1823

__attribute__((nonnull, warn_unused_result))

1824

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1825

mandos_context *mc){

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1826

1322

int ret;

1827

1323

struct timespec now;

1828

1324

struct timespec waited_time;

1829

1325

intmax_t block_time;

1830

1326

1831

1327

while(true){

1832

if(mc->current_server == NULL){

1833

if(debug){

1328

if(mc.current_server == NULL){

1329

if (debug){

1834

1330

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

1835

1331

" No timeout!\n");

1836

1332

}

1837

1333

ret = avahi_simple_poll_iterate(s, -1);

1838

1334

} else {

1839

if(debug){

1335

if (debug){

1840

1336

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

1841

1337

" it, or wait\n");

1842

1338

}

1849

1345

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

1850

1346

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

1851

1347

waited_time.tv_sec = (now.tv_sec

1852

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

1348

- mc.current_server->last_seen.tv_sec);

1853

1349

waited_time.tv_nsec = (now.tv_nsec

1854

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

1350

- mc.current_server->last_seen.tv_nsec);

1855

1351

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

1856

1352

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

1857

1353

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

1859

1355

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

1860

1356

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

1861

1357

1862

if(debug){

1358

if (debug){

1863

1359

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

1864

1360

block_time);

1865

1361

}

1866

1362

1867

1363

if(block_time <= 0){

1868

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

1869

mc->current_server->port,

1870

mc->current_server->if_index,

1871

mc->current_server->af, mc);

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);

1872

1368

if(ret == 0){

1873

avahi_simple_poll_quit(s);

1369

avahi_simple_poll_quit(mc.simple_poll);

1874

1370

return 0;

1875

1371

}

1876

1372

ret = clock_gettime(CLOCK_MONOTONIC,

1877

&mc->current_server->last_seen);

1373

&mc.current_server->last_seen);

1878

1374

if(ret == -1){

1879

1375

perror_plus("clock_gettime");

1880

1376

return -1;

1881

1377

}

1882

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

1378

mc.current_server = mc.current_server->next;

1883

1379

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

1884

1380

servers, but don't block */

1885

1381

}

1887

1383

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

1888

1384

}

1889

1385

if(ret != 0){

1890

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

1386

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

1891

1387

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

1892

1388

}

1893

1389

}

1894

1390

}

1895

1391

}

1896

1392

1897

__attribute__((nonnull))

1898

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

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,

1899

1446

const float delay){

1900

struct dirent **direntries = NULL;

1901

if(hookdir_fd == -1){

1902

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1903

| O_CLOEXEC);

1904

if(hookdir_fd == -1){

1905

if(errno == ENOENT){

1906

if(debug){

1907

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

1908

" found\n", hookdir);

1909

}

1910

} else {

1911

perror_plus("open");

1912

}

1913

return;

1914

}

1915

}

1916

#ifdef __GLIBC__

1917

#if __GLIBC_PREREQ(2, 15)

1918

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

1919

runnable_hook, alphasort);

1920

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

1921

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

1922

alphasort);

1923

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

1924

#else /* not __GLIBC__ */

1925

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

1926

alphasort);

1927

#endif /* not __GLIBC__ */

1447

struct dirent **direntries;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

1928

1452

if(numhooks == -1){

1929

perror_plus("scandir");

1930

return;

1931

}

1932

struct dirent *direntry;

1933

int ret;

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1939

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

1940

direntry = direntries[i];

1941

if(debug){

1942

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

1943

direntry->d_name);

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");

1944

1460

}

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

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

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

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

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

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

1990

if(ret == -1){

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){

1991

1468

perror_plus("asprintf");

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

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

}

1996

1527

free(delaystring);

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

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

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

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

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

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

2054

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

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

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

2061

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

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

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

}

2065

1539

} else {

2066

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

2067

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

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

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

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

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

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

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;

2085

1576

}

2086

1577

2087

__attribute__((nonnull, warn_unused_result))

2088

1578

error_t bring_up_interface(const char *const interface,

2089

1579

const float delay){

1580

int sd = -1;

2090

1581

error_t old_errno = errno;

2091

int ret;

1582

error_t ret_errno = 0;

1583

int ret, ret_setflags;

2092

1584

struct ifreq network;

2093

1585

unsigned int if_index = if_nametoindex(interface);

2094

1586

if(if_index == 0){

2103

1595

}

2104

1596

2105

1597

if(not interface_is_up(interface)){

2106

error_t ret_errno = 0, ioctl_errno = 0;

2107

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

1598

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

2108

1599

ret_errno = errno;

2109

1600

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

2110

1601

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

2111

errno = old_errno;

2112

1602

return ret_errno;

2113

1603

}

2114

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

1604

network.ifr_flags |= IFF_UP;

2115

1605

2116

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

2117

if(sd == -1){

1606

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1607

if(sd < 0){

2118

1608

ret_errno = errno;

2119

1609

perror_plus("socket");

2120

1610

errno = old_errno;

2121

1611

return ret_errno;

2122

1612

}

2123

1613

2124

1614

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

1615

close(sd);

2129

1616

errno = old_errno;

2130

1617

return EINTR;

2131

1618

}

2135

1622

interface);

2136

1623

}

2137

1624

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

1625

/* Raise priviliges */

1626

raise_privileges();

2144

1627

2145

1628

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

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");

2157

1636

}

2158

1637

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

1638

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

1639

ret_errno = errno;

2161

1640

#ifdef __linux__

2162

1641

if(restore_loglevel){

2163

1642

ret_linux = klogctl(7, NULL, 0);

2167

1646

}

2168

1647

#endif /* __linux__ */

2169

1648

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

1649

/* Lower privileges */

1650

lower_privileges();

2179

1651

2180

1652

/* Close the socket */

2181

ret = close(sd);

1653

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

2182

1654

if(ret == -1){

2183

1655

perror_plus("close");

2184

1656

}

2185

1657

2186

1658

if(ret_setflags == -1){

2187

errno = ioctl_errno;

1659

errno = ret_errno;

2188

1660

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

1661

errno = old_errno;

2190

return ioctl_errno;

1662

return ret_errno;

2191

1663

}

2192

1664

} else if(debug){

2193

1665

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

2211

1683

return 0;

2212

1684

}

2213

1685

2214

__attribute__((nonnull, warn_unused_result))

2215

1686

error_t take_down_interface(const char *const interface){

1687

int sd = -1;

2216

1688

error_t old_errno = errno;

1689

error_t ret_errno = 0;

1690

int ret, ret_setflags;

2217

1691

struct ifreq network;

2218

1692

unsigned int if_index = if_nametoindex(interface);

2219

1693

if(if_index == 0){

2222

1696

return ENXIO;

2223

1697

}

2224

1698

if(interface_is_up(interface)){

2225

error_t ret_errno = 0, ioctl_errno = 0;

2226

1699

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

2227

1700

ret_errno = errno;

2228

1701

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

2229

1702

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

2230

errno = old_errno;

2231

1703

return ret_errno;

2232

1704

}

2233

1705

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

2234

1706

2235

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

2236

if(sd == -1){

1707

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1708

if(sd < 0){

2237

1709

ret_errno = errno;

2238

1710

perror_plus("socket");

2239

1711

errno = old_errno;

2245

1717

interface);

2246

1718

}

2247

1719

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

2254

2255

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

2256

ioctl_errno = errno;

2257

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

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();

2267

1728

2268

1729

/* Close the socket */

2269

int ret = close(sd);

1730

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

2270

1731

if(ret == -1){

2271

1732

perror_plus("close");

2272

1733

}

2273

1734

2274

1735

if(ret_setflags == -1){

2275

errno = ioctl_errno;

1736

errno = ret_errno;

2276

1737

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2277

1738

errno = old_errno;

2278

return ioctl_errno;

1739

return ret_errno;

2279

1740

}

2280

1741

} else if(debug){

2281

1742

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

2287

1748

}

2288

1749

2289

1750

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

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

2295

1751

AvahiSServiceBrowser *sb = NULL;

2296

1752

error_t ret_errno;

2297

1753

int ret;

2298

1754

intmax_t tmpmax;

2299

1755

char *tmp;

2300

1756

int exitcode = EXIT_SUCCESS;

1757

char *interfaces = NULL;

1758

size_t interfaces_size = 0;

2301

1759

char *interfaces_to_take_down = NULL;

2302

1760

size_t interfaces_to_take_down_size = 0;

2303

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

2304

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

2305

char *tempdir = NULL;

1761

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

1762

bool tempdir_created = false;

2306

1763

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2307

1764

const char *seckey = PATHDIR "/" SECKEY;

2308

1765

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

2310

1766

char *interfaces_hooks = NULL;

1767

size_t interfaces_hooks_size = 0;

2311

1768

2312

1769

bool gnutls_initialized = false;

2313

1770

bool gpgme_initialized = false;

2365

1822

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

2366

1823

" Diffie-Hellman key exchange",

2367

1824

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

2373

1825

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

2374

1826

.arg = "STRING",

2375

1827

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

2409

1861

connect_to = arg;

2410

1862

break;

2411

1863

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

2412

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

2413

arg, (int)',');

1864

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

1865

(int)',');

2414

1866

if(ret_errno != 0){

2415

1867

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

2416

1868

}

2430

1882

}

2431

1883

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

2432

1884

break;

2433

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

2434

dh_params_file = arg;

2435

break;

2436

1885

case 130: /* --priority */

2437

1886

mc.priority = arg;

2438

1887

break;

2494

1943

goto end;

2495

1944

}

2496

1945

}

2497

1946

2498

1947

{

2499

1948

/* Work around Debian bug #633582:

2500

1949

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

2501

1950

2502

/* Re-raise privileges */

2503

ret_errno = raise_privileges();

2504

if(ret_errno != 0){

2505

errno = ret_errno;

2506

perror_plus("Failed to raise privileges");

2507

} else {

1951

/* Re-raise priviliges */

1952

if(raise_privileges() == 0){

2508

1953

struct stat st;

2509

1954

2510

1955

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

2524

1969

}

2525

1970

}

2526

1971

}

2527

close(seckey_fd);

1972

TEMP_FAILURE_RETRY(close(seckey_fd));

2528

1973

}

2529

1974

}

2530

1975

2531

1976

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

2532

1977

int pubkey_fd = open(pubkey, O_RDONLY);

2533

1978

if(pubkey_fd == -1){

2545

1990

}

2546

1991

}

2547

1992

}

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

1993

TEMP_FAILURE_RETRY(close(pubkey_fd));

1994

}

1995

}

1996

2574

1997

/* Lower privileges */

2575

ret_errno = lower_privileges();

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to lower privileges");

1998

errno = 0;

1999

ret = seteuid(uid);

2000

if(ret == -1){

2001

perror_plus("seteuid");

2579

2002

}

2580

2003

}

2581

2004

}

2582

2005

2583

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

2006

/* Remove empty interface names */

2584

2007

{

2585

2008

char *interface = NULL;

2586

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

2009

while((interface = argz_next(interfaces, interfaces_size,

2587

2010

interface))){

2588

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

2589

and if_nametoindex(interface) == 0){

2590

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

2011

if(if_nametoindex(interface) == 0){

2012

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

2591

2013

fprintf_plus(stderr, "Not using nonexisting interface"

2592

2014

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

2593

2015

}

2594

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

2016

argz_delete(&interfaces, &interfaces_size, interface);

2595

2017

interface = NULL;

2596

2018

}

2597

2019

}

2599

2021

2600

2022

/* Run network hooks */

2601

2023

{

2602

if(mc.interfaces != NULL){

2603

interfaces_hooks = malloc(mc.interfaces_size);

2024

2025

if(interfaces != NULL){

2026

interfaces_hooks = malloc(interfaces_size);

2604

2027

if(interfaces_hooks == NULL){

2605

2028

perror_plus("malloc");

2606

2029

goto end;

2607

2030

}

2608

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

2609

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

2610

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

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

}

2613

2040

}

2614

2041

2615

2042

if(not debug){

2620

2047

from the signal handler */

2621

2048

/* Initialize the pseudo-RNG for Avahi */

2622

2049

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

2623

simple_poll = avahi_simple_poll_new();

2624

if(simple_poll == NULL){

2050

mc.simple_poll = avahi_simple_poll_new();

2051

if(mc.simple_poll == NULL){

2625

2052

fprintf_plus(stderr,

2626

2053

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

2627

2054

exitcode = EX_UNAVAILABLE;

2692

2119

}

2693

2120

2694

2121

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

2695

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2122

if(interfaces == NULL){

2123

struct dirent **direntries;

2697

2124

/* Look for any good interfaces */

2698

2125

ret = scandir(sys_class_net, &direntries, good_interface,

2699

2126

alphasort);

2700

2127

if(ret >= 1){

2701

2128

/* Add all found interfaces to interfaces list */

2702

2129

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

2703

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

2130

ret_errno = argz_add(&interfaces, &interfaces_size,

2704

2131

direntries[i]->d_name);

2705

2132

if(ret_errno != 0){

2706

errno = ret_errno;

2707

2133

perror_plus("argz_add");

2708

free(direntries[i]);

2709

2134

continue;

2710

2135

}

2711

2136

if(debug){

2712

2137

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

2713

2138

direntries[i]->d_name);

2714

2139

}

2715

free(direntries[i]);

2716

2140

}

2717

2141

free(direntries);

2718

2142

} else {

2719

if(ret == 0){

2720

free(direntries);

2721

}

2143

free(direntries);

2722

2144

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

2723

2145

exitcode = EXIT_FAILURE;

2724

2146

goto end;

2725

2147

}

2726

2148

}

2727

2149

2728

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

2729

{

2150

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

2151

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

2152

if(debug){

2153

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

2154

interfaces);

2155

}

2156

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2157

}

2158

2159

/* Bring up interfaces which are down */

2160

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

2161

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

2730

2162

char *interface = NULL;

2731

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

2163

while((interface = argz_next(interfaces, interfaces_size,

2732

2164

interface))){

2733

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

2734

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

2735

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

2736

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

2737

interface);

2738

interface = NULL;

2739

while((interface = argz_next(mc.interfaces,

2740

mc.interfaces_size, interface))){

2741

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

2742

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

2743

interface);

2744

interface = NULL;

2745

}

2746

}

2747

break;

2748

}

2749

2165

bool interface_was_up = interface_is_up(interface);

2750

errno = bring_up_interface(interface, delay);

2166

ret = bring_up_interface(interface, delay);

2751

2167

if(not interface_was_up){

2752

if(errno != 0){

2753

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

2754

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

2168

if(ret != 0){

2169

errno = ret;

2170

perror_plus("Failed to bring up interface");

2755

2171

} else {

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

2760

perror_plus("argz_add");

2761

}

2172

ret_errno = argz_add(&interfaces_to_take_down,

2173

&interfaces_to_take_down_size,

2174

interface);

2762

2175

}

2763

2176

}

2764

2177

}

2178

free(interfaces);

2179

interfaces = NULL;

2180

interfaces_size = 0;

2765

2181

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

2766

2182

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

2767

2183

}

2768

2184

}

2769

2185

2770

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

2771

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

2772

if(debug){

2773

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

2774

mc.interfaces);

2775

}

2776

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

2777

}

2778

2779

2186

if(quit_now){

2780

2187

goto end;

2781

2188

}

2782

2189

2783

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

2190

ret = init_gnutls_global(pubkey, seckey);

2784

2191

if(ret == -1){

2785

2192

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

2786

2193

exitcode = EX_UNAVAILABLE;

2793

2200

goto end;

2794

2201

}

2795

2202

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

2203

if(mkdtemp(tempdir) == NULL){

2806

2204

perror_plus("mkdtemp");

2807

2205

goto end;

2808

2206

}

2207

tempdir_created = true;

2809

2208

2810

2209

if(quit_now){

2811

2210

goto end;

2812

2211

}

2813

2212

2814

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

2213

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

2815

2214

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

2816

2215

exitcode = EX_UNAVAILABLE;

2817

2216

goto end;

2847

2246

exitcode = EX_USAGE;

2848

2247

goto end;

2849

2248

}

2850

2249

2851

2250

if(quit_now){

2852

2251

goto end;

2853

2252

}

2874

2273

}

2875

2274

2876

2275

while(not quit_now){

2877

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

2878

&mc);

2276

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

2879

2277

if(quit_now or ret == 0){

2880

2278

break;

2881

2279

}

2883

2281

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

2884

2282

(int)retry_interval);

2885

2283

}

2886

sleep((unsigned int)retry_interval);

2284

sleep((int)retry_interval);

2887

2285

}

2888

2286

2889

if(not quit_now){

2287

if (not quit_now){

2890

2288

exitcode = EXIT_SUCCESS;

2891

2289

}

2892

2290

2907

2305

config.publish_domain = 0;

2908

2306

2909

2307

/* Allocate a new server */

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2911

&config, NULL, NULL, &ret_errno);

2308

mc.server = avahi_server_new(avahi_simple_poll_get

2309

(mc.simple_poll), &config, NULL,

2310

NULL, &ret_errno);

2912

2311

2913

2312

/* Free the Avahi configuration data */

2914

2313

avahi_server_config_free(&config);

2929

2328

/* Create the Avahi service browser */

2930

2329

sb = avahi_s_service_browser_new(mc.server, if_index,

2931

2330

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2932

NULL, 0, browse_callback,

2933

(void *)&mc);

2331

NULL, 0, browse_callback, NULL);

2934

2332

if(sb == NULL){

2935

2333

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

2936

2334

avahi_strerror(avahi_server_errno(mc.server)));

2947

2345

if(debug){

2948

2346

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

2949

2347

}

2950

2951

ret = avahi_loop_with_timeout(simple_poll,

2952

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

2348

2349

ret = avahi_loop_with_timeout(mc.simple_poll,

2350

(int)(retry_interval * 1000));

2953

2351

if(debug){

2954

2352

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

2955

2353

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

2962

2360

}

2963

2361

2964

2362

/* Cleanup things */

2965

free(mc.interfaces);

2966

2967

2363

if(sb != NULL)

2968

2364

avahi_s_service_browser_free(sb);

2969

2365

2970

2366

if(mc.server != NULL)

2971

2367

avahi_server_free(mc.server);

2972

2368

2973

if(simple_poll != NULL)

2974

avahi_simple_poll_free(simple_poll);

2369

if(mc.simple_poll != NULL)

2370

avahi_simple_poll_free(mc.simple_poll);

2975

2371

2976

2372

if(gnutls_initialized){

2977

2373

gnutls_certificate_free_credentials(mc.cred);

2989

2385

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

2990

2386

while(mc.current_server != NULL){

2991

2387

server *next = mc.current_server->next;

2992

#ifdef __GNUC__

2993

#pragma GCC diagnostic push

2994

#pragma GCC diagnostic ignored "-Wcast-qual"

2995

#endif

2996

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

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic pop

2999

#endif

3000

2388

free(mc.current_server);

3001

2389

mc.current_server = next;

3002

2390

}

3003

2391

}

3004

2392

3005

/* Re-raise privileges */

2393

/* Re-raise priviliges */

3006

2394

{

3007

ret_errno = raise_privileges();

3008

if(ret_errno != 0){

3009

errno = ret_errno;

3010

perror_plus("Failed to raise privileges");

3011

} else {

3012

3013

/* Run network hooks */

3014

run_network_hooks("stop", interfaces_hooks != NULL ?

3015

interfaces_hooks : "", delay);

3016

3017

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

3018

{

3019

char *interface = NULL;

3020

while((interface=argz_next(interfaces_to_take_down,

3021

interfaces_to_take_down_size,

3022

interface))){

3023

ret_errno = take_down_interface(interface);

3024

if(ret_errno != 0){

3025

errno = ret_errno;

3026

perror_plus("Failed to take down interface");

3027

}

3028

}

3029

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

3030

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

3031

" down\n");

3032

}

3033

}

3034

}

3035

3036

ret_errno = lower_privileges_permanently();

3037

if(ret_errno != 0){

3038

errno = ret_errno;

3039

perror_plus("Failed to lower privileges permanently");

3040

}

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();

3041

2420

}

3042

2421

3043

2422

free(interfaces_to_take_down);

3044

2423

free(interfaces_hooks);

3045

2424

3046

2425

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

3047

if(tempdir != NULL){

2426

if(tempdir_created){

3048

2427

struct dirent **direntries = NULL;

3049

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

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(tempdir_fd == -1){

3054

perror_plus("open");

3055

} else {

3056

#ifdef __GLIBC__

3057

#if __GLIBC_PREREQ(2, 15)

3058

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

3059

notdotentries, alphasort);

3060

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

3061

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

3062

alphasort);

3063

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

3064

#else /* not __GLIBC__ */

3065

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

3066

alphasort);

3067

#endif /* not __GLIBC__ */

3068

if(numentries >= 0){

3069

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

3070

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

3071

if(ret == -1){

3072

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

3073

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

3074

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

3075

}

3076

free(direntries[i]);

3077

}

3078

3079

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

3080

free(direntries);

3081

if(numentries == -1){

3082

perror_plus("scandir");

3083

}

3084

ret = rmdir(tempdir);

3085

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

3086

perror_plus("rmdir");

3087

}

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);

3088

2447

}

3089

close(tempdir_fd);

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");

3090

2458

}

3091

2459

}

3092

2460