/mandos/release : revision 237.7.337

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

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

43

stdout, ferror() */

44

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

45

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

46

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

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strtof(), abort() */

48

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

49

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

50

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

49

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

50

asprintf(), 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,

58

inet_pton(), connect() */

59

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

72

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,

91

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;

169

char *interfaces;

170

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

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

623

1041

/* Called when a Mandos server is found */

1042

__attribute__((nonnull, warn_unused_result))

624

1043

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

625

1044

AvahiIfIndex if_index,

626

int af){

1045

int af, mandos_context *mc){

627

1046

int ret, tcp_sd = -1;

628

1047

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1048

struct sockaddr_storage to;

633

1049

char *buffer = NULL;

634

1050

char *decrypted_buffer = NULL;

635

1051

size_t buffer_length = 0;

638

1054

int retval = -1;

639

1055

gnutls_session_t session;

640

1056

int pf; /* Protocol family */

1057

bool route_added = false;

641

1058

642

1059

errno = 0;

643

1060

659

1076

return -1;

660

1077

}

661

1078

662

ret = init_gnutls_session(&session);

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);

663

1112

if(ret != 0){

664

1113

return -1;

665

1114

}

669

1118

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

670

1119

}

671

1120

672

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

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

673

1122

if(tcp_sd < 0){

674

1123

int e = errno;

675

1124

perror_plus("socket");

682

1131

goto mandos_end;

683

1132

}

684

1133

685

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

686

1134

if(af == AF_INET6){

687

to.in6.sin6_family = (sa_family_t)af;

688

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

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);

689

1138

} else { /* IPv4 */

690

to.in.sin_family = (sa_family_t)af;

691

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

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);

692

1142

}

693

1143

if(ret < 0 ){

694

1144

int e = errno;

703

1153

goto mandos_end;

704

1154

}

705

1155

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*/

1156

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

1157

if(IN6_IS_ADDR_LINKLOCAL

1158

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

710

1159

if(if_index == AVAHI_IF_UNSPEC){

711

1160

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

712

1161

" incomplete without a network interface\n");

714

1163

goto mandos_end;

715

1164

}

716

1165

/* Set the network interface number as scope */

717

to.in6.sin6_scope_id = (uint32_t)if_index;

1166

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

718

1167

}

719

1168

} else {

720

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

721

-Wconversion and

722

-Wunreachable-code */

1169

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

723

1170

}

724

1171

725

1172

if(quit_now){

742

1189

}

743

1190

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

744

1191

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;

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;

784

1272

}

785

1273

786

1274

const char *out = mandos_protocol_version;

937

1425

if(buffer_length > 0){

938

1426

ssize_t decrypted_buffer_size;

939

1427

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

940

&decrypted_buffer);

1428

&decrypted_buffer, mc);

941

1429

if(decrypted_buffer_size >= 0){

942

1430

943

1431

written = 0;

969

1457

970

1458

mandos_end:

971

1459

{

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

}

972

1466

int e = errno;

973

1467

free(decrypted_buffer);

974

1468

free(buffer);

975

1469

if(tcp_sd >= 0){

976

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

1470

ret = close(tcp_sd);

977

1471

}

978

1472

if(ret == -1){

979

1473

if(e == 0){

991

1485

return retval;

992

1486

}

993

1487

1488

__attribute__((nonnull))

994

1489

static void resolve_callback(AvahiSServiceResolver *r,

995

1490

AvahiIfIndex interface,

996

1491

AvahiProtocol proto,

1004

1499

AVAHI_GCC_UNUSED AvahiStringList *txt,

1005

1500

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1006

1501

flags,

1007

AVAHI_GCC_UNUSED void* userdata){

1502

void *mc){

1008

1503

if(r == NULL){

1009

1504

return;

1010

1505

}

1013

1508

timed out */

1014

1509

1015

1510

if(quit_now){

1511

avahi_s_service_resolver_free(r);

1016

1512

return;

1017

1513

}

1018

1514

1022

1518

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

1023

1519

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

1024

1520

domain,

1025

avahi_strerror(avahi_server_errno(mc.server)));

1521

avahi_strerror(avahi_server_errno

1522

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

1026

1523

break;

1027

1524

1028

1525

case AVAHI_RESOLVER_FOUND:

1036

1533

}

1037

1534

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

1038

1535

interface,

1039

avahi_proto_to_af(proto));

1536

avahi_proto_to_af(proto),

1537

mc);

1040

1538

if(ret == 0){

1041

avahi_simple_poll_quit(mc.simple_poll);

1539

avahi_simple_poll_quit(simple_poll);

1042

1540

} else {

1043

1541

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

1044

avahi_proto_to_af(proto))){

1542

avahi_proto_to_af(proto),

1543

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

1045

1544

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

1046

1545

" list\n", name);

1047

1546

}

1060

1559

const char *domain,

1061

1560

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1062

1561

flags,

1063

AVAHI_GCC_UNUSED void* userdata){

1562

void *mc){

1064

1563

if(b == NULL){

1065

1564

return;

1066

1565

}

1077

1576

case AVAHI_BROWSER_FAILURE:

1078

1577

1079

1578

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1579

avahi_strerror(avahi_server_errno

1580

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

1581

avahi_simple_poll_quit(simple_poll);

1082

1582

return;

1083

1583

1084

1584

case AVAHI_BROWSER_NEW:

1087

1587

the callback function is called the Avahi server will free the

1088

1588

resolver for us. */

1089

1589

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

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)

1093

1594

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

1094

1595

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1596

avahi_strerror(avahi_server_errno

1597

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

1096

1598

break;

1097

1599

1098

1600

case AVAHI_BROWSER_REMOVE:

1117

1619

signal_received = sig;

1118

1620

int old_errno = errno;

1119

1621

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1622

if(simple_poll != NULL){

1623

avahi_simple_poll_quit(simple_poll);

1122

1624

}

1123

1625

errno = old_errno;

1124

1626

}

1125

1627

1628

__attribute__((nonnull, warn_unused_result))

1126

1629

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

1127

1630

int ret;

1128

1631

error_t ret_errno;

1147

1650

return true;

1148

1651

}

1149

1652

1653

__attribute__((nonnull, warn_unused_result))

1150

1654

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

1151

1655

1152

1656

/* Reject the loopback device */

1194

1698

* corresponds to an acceptable network device.

1195

1699

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

1196

1700

*/

1701

__attribute__((nonnull, warn_unused_result))

1197

1702

int good_interface(const struct dirent *if_entry){

1198

1703

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

1199

1704

return 0;

1217

1722

/*

1218

1723

* This function determines if a network interface is up.

1219

1724

*/

1725

__attribute__((nonnull, warn_unused_result))

1220

1726

bool interface_is_up(const char *interface){

1221

1727

struct ifreq ifr;

1222

1728

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

1233

1739

/*

1234

1740

* This function determines if a network interface is running

1235

1741

*/

1742

__attribute__((nonnull, warn_unused_result))

1236

1743

bool interface_is_running(const char *interface){

1237

1744

struct ifreq ifr;

1238

1745

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

1246

1753

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

1247

1754

}

1248

1755

1756

__attribute__((nonnull, pure, warn_unused_result))

1249

1757

int notdotentries(const struct dirent *direntry){

1250

1758

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

1251

1759

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

1258

1766

}

1259

1767

1260

1768

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

1769

__attribute__((nonnull, warn_unused_result))

1261

1770

int runnable_hook(const struct dirent *direntry){

1262

1771

int ret;

1263

1772

size_t sret;

1271

1780

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

1272

1781

"abcdefghijklmnopqrstuvwxyz"

1273

1782

"0123456789"

1274

"_-");

1783

"_.-");

1275

1784

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

1276

1785

/* Contains non-allowed characters */

1277

1786

if(debug){

1281

1790

return 0;

1282

1791

}

1283

1792

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);

1793

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

1292

1794

if(ret == -1){

1293

1795

if(debug){

1294

1796

perror_plus("Could not stat hook");

1318

1820

return 1;

1319

1821

}

1320

1822

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1823

__attribute__((nonnull, warn_unused_result))

1824

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1825

mandos_context *mc){

1322

1826

int ret;

1323

1827

struct timespec now;

1324

1828

struct timespec waited_time;

1325

1829

intmax_t block_time;

1326

1830

1327

1831

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1832

if(mc->current_server == NULL){

1833

if(debug){

1330

1834

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

1331

1835

" No timeout!\n");

1332

1836

}

1333

1837

ret = avahi_simple_poll_iterate(s, -1);

1334

1838

} else {

1335

if (debug){

1839

if(debug){

1336

1840

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

1337

1841

" it, or wait\n");

1338

1842

}

1345

1849

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

1346

1850

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

1347

1851

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1852

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

1349

1853

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1854

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

1351

1855

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

1352

1856

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

1353

1857

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

1355

1859

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

1356

1860

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

1357

1861

1358

if (debug){

1862

if(debug){

1359

1863

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

1360

1864

block_time);

1361

1865

}

1362

1866

1363

1867

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);

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);

1368

1872

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1873

avahi_simple_poll_quit(s);

1370

1874

return 0;

1371

1875

}

1372

1876

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1877

&mc->current_server->last_seen);

1374

1878

if(ret == -1){

1375

1879

perror_plus("clock_gettime");

1376

1880

return -1;

1377

1881

}

1378

mc.current_server = mc.current_server->next;

1882

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

1379

1883

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

1380

1884

servers, but don't block */

1381

1885

}

1383

1887

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

1384

1888

}

1385

1889

if(ret != 0){

1386

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

1890

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

1387

1891

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

1388

1892

}

1389

1893

}

1390

1894

}

1391

1895

}

1392

1896

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,

1897

__attribute__((nonnull))

1898

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

1446

1899

const float delay){

1447

struct dirent **direntries;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

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__ */

1452

1928

if(numhooks == -1){

1453

1929

perror_plus("scandir");

1454

} else {

1455

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

1456

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

1457

direntry = direntries[i];

1458

char *fullname = NULL;

1459

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

1460

if(ret < 0){

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);

1944

}

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

1991

perror_plus("asprintf");

1462

continue;

1463

}

1464

if(debug){

1465

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

1466

direntry->d_name);

1467

}

1468

pid_t hook_pid = fork();

1469

if(hook_pid == 0){

1470

/* Child */

1471

/* Raise privileges */

1472

raise_privileges_permanently();

1473

/* Set group */

1474

errno = 0;

1475

ret = setgid(0);

1476

if(ret == -1){

1477

perror_plus("setgid");

1478

}

1479

/* Reset supplementary groups */

1480

errno = 0;

1481

ret = setgroups(0, NULL);

1482

if(ret == -1){

1483

perror_plus("setgroups");

1484

}

1485

dup2(devnull, STDIN_FILENO);

1486

close(devnull);

1487

dup2(STDERR_FILENO, STDOUT_FILENO);

1488

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

1489

if(ret == -1){

1490

perror_plus("setenv");

1491

_exit(EX_OSERR);

1492

}

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

char *delaystring;

1509

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

1510

if(ret == -1){

1511

perror_plus("asprintf");

1512

_exit(EX_OSERR);

1513

}

1514

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

1515

if(ret == -1){

1516

free(delaystring);

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1520

1996

free(delaystring);

1521

if(connect_to != NULL){

1522

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

1523

if(ret == -1){

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1527

}

1528

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

1529

perror_plus("execl");

1530

_exit(EXIT_FAILURE);

1531

}

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;

1532

2065

} else {

1533

int status;

1534

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

1535

perror_plus("waitpid");

1536

free(fullname);

1537

continue;

1538

}

1539

if(WIFEXITED(status)){

1540

if(WEXITSTATUS(status) != 0){

1541

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

1542

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

1543

WEXITSTATUS(status));

1544

free(fullname);

1545

continue;

1546

}

1547

} else if(WIFSIGNALED(status)){

1548

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

1549

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

1550

WTERMSIG(status));

1551

free(fullname);

1552

continue;

1553

} else {

1554

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

1555

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

1556

free(fullname);

1557

continue;

1558

}

1559

}

1560

free(fullname);

1561

if(debug){

1562

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

1563

direntry->d_name);

1564

}

1565

}

1566

close(devnull);

1567

}

1568

return true;

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);

1569

2085

}

1570

2086

2087

__attribute__((nonnull, warn_unused_result))

1571

2088

error_t bring_up_interface(const char *const interface,

1572

2089

const float delay){

1573

int sd = -1;

1574

2090

error_t old_errno = errno;

1575

error_t ret_errno = 0;

1576

int ret, ret_setflags;

2091

int ret;

1577

2092

struct ifreq network;

1578

2093

unsigned int if_index = if_nametoindex(interface);

1579

2094

if(if_index == 0){

1588

2103

}

1589

2104

1590

2105

if(not interface_is_up(interface)){

1591

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

2106

error_t ret_errno = 0, ioctl_errno = 0;

2107

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

1592

2108

ret_errno = errno;

1593

2109

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

1594

2110

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

2111

errno = old_errno;

1595

2112

return ret_errno;

1596

2113

}

1597

network.ifr_flags |= IFF_UP;

2114

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

1598

2115

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

2116

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

2117

if(sd == -1){

1601

2118

ret_errno = errno;

1602

2119

perror_plus("socket");

1603

2120

errno = old_errno;

1604

2121

return ret_errno;

1605

2122

}

1606

2123

1607

2124

if(quit_now){

1608

close(sd);

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

1609

2129

errno = old_errno;

1610

2130

return EINTR;

1611

2131

}

1615

2135

interface);

1616

2136

}

1617

2137

1618

/* Raise priviliges */

1619

raise_privileges();

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

}

1620

2144

1621

2145

#ifdef __linux__

1622

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1623

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

1624

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

1625

bool restore_loglevel = true;

1626

if(ret_linux == -1){

1627

restore_loglevel = false;

1628

perror_plus("klogctl");

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

2157

}

1630

2158

#endif /* __linux__ */

1631

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

1632

ret_errno = errno;

2159

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

2160

ioctl_errno = errno;

1633

2161

#ifdef __linux__

1634

2162

if(restore_loglevel){

1635

2163

ret_linux = klogctl(7, NULL, 0);

1639

2167

}

1640

2168

#endif /* __linux__ */

1641

2169

1642

/* Lower privileges */

1643

lower_privileges();

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

}

1644

2179

1645

2180

/* Close the socket */

1646

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

2181

ret = close(sd);

1647

2182

if(ret == -1){

1648

2183

perror_plus("close");

1649

2184

}

1650

2185

1651

2186

if(ret_setflags == -1){

1652

errno = ret_errno;

2187

errno = ioctl_errno;

1653

2188

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1654

2189

errno = old_errno;

1655

return ret_errno;

2190

return ioctl_errno;

1656

2191

}

1657

2192

} else if(debug){

1658

2193

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

1676

2211

return 0;

1677

2212

}

1678

2213

2214

__attribute__((nonnull, warn_unused_result))

1679

2215

error_t take_down_interface(const char *const interface){

1680

int sd = -1;

1681

2216

error_t old_errno = errno;

1682

error_t ret_errno = 0;

1683

int ret, ret_setflags;

1684

2217

struct ifreq network;

1685

2218

unsigned int if_index = if_nametoindex(interface);

1686

2219

if(if_index == 0){

1689

2222

return ENXIO;

1690

2223

}

1691

2224

if(interface_is_up(interface)){

2225

error_t ret_errno = 0, ioctl_errno = 0;

1692

2226

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

1693

2227

ret_errno = errno;

1694

2228

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

1695

2229

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

2230

errno = old_errno;

1696

2231

return ret_errno;

1697

2232

}

1698

2233

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

1699

2234

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

2235

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

2236

if(sd == -1){

1702

2237

ret_errno = errno;

1703

2238

perror_plus("socket");

1704

2239

errno = old_errno;

1710

2245

interface);

1711

2246

}

1712

2247

1713

/* Raise priviliges */

1714

raise_privileges();

1715

1716

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

1717

ret_errno = errno;

1718

1719

/* Lower privileges */

1720

lower_privileges();

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

}

1721

2267

1722

2268

/* Close the socket */

1723

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

2269

int ret = close(sd);

1724

2270

if(ret == -1){

1725

2271

perror_plus("close");

1726

2272

}

1727

2273

1728

2274

if(ret_setflags == -1){

1729

errno = ret_errno;

2275

errno = ioctl_errno;

1730

2276

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1731

2277

errno = old_errno;

1732

return ret_errno;

2278

return ioctl_errno;

1733

2279

}

1734

2280

} else if(debug){

1735

2281

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

1741

2287

}

1742

2288

1743

2289

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 };

1744

2295

AvahiSServiceBrowser *sb = NULL;

1745

2296

error_t ret_errno;

1746

2297

int ret;

1747

2298

intmax_t tmpmax;

1748

2299

char *tmp;

1749

2300

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

1752

2301

char *interfaces_to_take_down = NULL;

1753

2302

size_t interfaces_to_take_down_size = 0;

1754

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

1755

bool tempdir_created = false;

2303

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

2304

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

2305

char *tempdir = NULL;

1756

2306

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1757

2307

const char *seckey = PATHDIR "/" SECKEY;

1758

2308

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

1759

2310

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

1761

2311

1762

2312

bool gnutls_initialized = false;

1763

2313

bool gpgme_initialized = false;

1815

2365

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

1816

2366

" Diffie-Hellman key exchange",

1817

2367

.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 },

1818

2373

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

1819

2374

.arg = "STRING",

1820

2375

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

1854

2409

connect_to = arg;

1855

2410

break;

1856

2411

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

1857

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

1858

(int)',');

2412

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

2413

arg, (int)',');

1859

2414

if(ret_errno != 0){

1860

2415

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

1861

2416

}

1875

2430

}

1876

2431

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

1877

2432

break;

2433

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

2434

dh_params_file = arg;

2435

break;

1878

2436

case 130: /* --priority */

1879

2437

mc.priority = arg;

1880

2438

break;

1936

2494

goto end;

1937

2495

}

1938

2496

}

1939

2497

1940

2498

{

1941

2499

/* Work around Debian bug #633582:

1942

2500

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

1943

2501

1944

/* Re-raise priviliges */

1945

if(raise_privileges() == 0){

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 {

1946

2508

struct stat st;

1947

2509

1948

2510

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

1962

2524

}

1963

2525

}

1964

2526

}

1965

TEMP_FAILURE_RETRY(close(seckey_fd));

2527

close(seckey_fd);

1966

2528

}

1967

2529

}

1968

2530

1969

2531

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

1970

2532

int pubkey_fd = open(pubkey, O_RDONLY);

1971

2533

if(pubkey_fd == -1){

1983

2545

}

1984

2546

}

1985

2547

}

1986

TEMP_FAILURE_RETRY(close(pubkey_fd));

1987

}

1988

}

1989

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

1990

2574

/* Lower privileges */

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2575

ret_errno = lower_privileges();

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to lower privileges");

1995

2579

}

1996

2580

}

1997

2581

}

1998

2582

1999

/* Remove empty interface names */

2583

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

2000

2584

{

2001

2585

char *interface = NULL;

2002

while((interface = argz_next(interfaces, interfaces_size,

2586

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

2003

2587

interface))){

2004

if(if_nametoindex(interface) == 0){

2005

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

2588

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

2589

and if_nametoindex(interface) == 0){

2590

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

2006

2591

fprintf_plus(stderr, "Not using nonexisting interface"

2007

2592

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

2008

2593

}

2009

argz_delete(&interfaces, &interfaces_size, interface);

2594

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

2010

2595

interface = NULL;

2011

2596

}

2012

2597

}

2014

2599

2015

2600

/* Run network hooks */

2016

2601

{

2017

ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,

2018

interfaces, interfaces_size);

2019

if(ret_errno != 0){

2020

errno = ret_errno;

2021

perror_plus("argz_append");

2022

goto end;

2023

}

2024

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

2025

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

2026

goto end;

2027

}

2602

if(mc.interfaces != NULL){

2603

interfaces_hooks = malloc(mc.interfaces_size);

2604

if(interfaces_hooks == NULL){

2605

perror_plus("malloc");

2606

goto end;

2607

}

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);

2028

2613

}

2029

2614

2030

2615

if(not debug){

2035

2620

from the signal handler */

2036

2621

/* Initialize the pseudo-RNG for Avahi */

2037

2622

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

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2623

simple_poll = avahi_simple_poll_new();

2624

if(simple_poll == NULL){

2040

2625

fprintf_plus(stderr,

2041

2626

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

2042

2627

exitcode = EX_UNAVAILABLE;

2107

2692

}

2108

2693

2109

2694

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

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2695

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2112

2697

/* Look for any good interfaces */

2113

2698

ret = scandir(sys_class_net, &direntries, good_interface,

2114

2699

alphasort);

2115

2700

if(ret >= 1){

2116

2701

/* Add all found interfaces to interfaces list */

2117

2702

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2703

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

2119

2704

direntries[i]->d_name);

2120

2705

if(ret_errno != 0){

2706

errno = ret_errno;

2121

2707

perror_plus("argz_add");

2708

free(direntries[i]);

2122

2709

continue;

2123

2710

}

2124

2711

if(debug){

2125

2712

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

2126

2713

direntries[i]->d_name);

2127

2714

}

2715

free(direntries[i]);

2128

2716

}

2129

2717

free(direntries);

2130

2718

} else {

2131

free(direntries);

2719

if(ret == 0){

2720

free(direntries);

2721

}

2132

2722

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

2133

2723

exitcode = EXIT_FAILURE;

2134

2724

goto end;

2135

2725

}

2136

2726

}

2137

2727

2138

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

2139

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

2140

if(debug){

2141

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

2142

interfaces);

2143

}

2144

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2145

}

2146

2147

/* Bring up interfaces which are down */

2148

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

2149

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

2728

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

2729

{

2150

2730

char *interface = NULL;

2151

while((interface = argz_next(interfaces, interfaces_size,

2731

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

2152

2732

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

}

2153

2749

bool interface_was_up = interface_is_up(interface);

2154

ret = bring_up_interface(interface, delay);

2750

errno = bring_up_interface(interface, delay);

2155

2751

if(not interface_was_up){

2156

if(ret != 0){

2157

errno = ret;

2158

perror_plus("Failed to bring up interface");

2752

if(errno != 0){

2753

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

2754

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

2159

2755

} else {

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

interface);

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

}

2163

2762

}

2164

2763

}

2165

2764

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2169

2765

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

2170

2766

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

2171

2767

}

2172

2768

}

2173

2769

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

2174

2779

if(quit_now){

2175

2780

goto end;

2176

2781

}

2177

2782

2178

ret = init_gnutls_global(pubkey, seckey);

2783

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

2179

2784

if(ret == -1){

2180

2785

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

2181

2786

exitcode = EX_UNAVAILABLE;

2188

2793

goto end;

2189

2794

}

2190

2795

2191

if(mkdtemp(tempdir) == NULL){

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){

2192

2806

perror_plus("mkdtemp");

2193

2807

goto end;

2194

2808

}

2195

tempdir_created = true;

2196

2809

2197

2810

if(quit_now){

2198

2811

goto end;

2199

2812

}

2200

2813

2201

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

2814

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

2202

2815

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

2203

2816

exitcode = EX_UNAVAILABLE;

2204

2817

goto end;

2234

2847

exitcode = EX_USAGE;

2235

2848

goto end;

2236

2849

}

2237

2850

2238

2851

if(quit_now){

2239

2852

goto end;

2240

2853

}

2261

2874

}

2262

2875

2263

2876

while(not quit_now){

2264

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

2877

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

2878

&mc);

2265

2879

if(quit_now or ret == 0){

2266

2880

break;

2267

2881

}

2269

2883

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

2270

2884

(int)retry_interval);

2271

2885

}

2272

sleep((int)retry_interval);

2886

sleep((unsigned int)retry_interval);

2273

2887

}

2274

2888

2275

if (not quit_now){

2889

if(not quit_now){

2276

2890

exitcode = EXIT_SUCCESS;

2277

2891

}

2278

2892

2293

2907

config.publish_domain = 0;

2294

2908

2295

2909

/* Allocate a new server */

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2911

&config, NULL, NULL, &ret_errno);

2299

2912

2300

2913

/* Free the Avahi configuration data */

2301

2914

avahi_server_config_free(&config);

2316

2929

/* Create the Avahi service browser */

2317

2930

sb = avahi_s_service_browser_new(mc.server, if_index,

2318

2931

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2319

NULL, 0, browse_callback, NULL);

2932

NULL, 0, browse_callback,

2933

(void *)&mc);

2320

2934

if(sb == NULL){

2321

2935

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

2322

2936

avahi_strerror(avahi_server_errno(mc.server)));

2333

2947

if(debug){

2334

2948

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

2335

2949

}

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2950

2951

ret = avahi_loop_with_timeout(simple_poll,

2952

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

2339

2953

if(debug){

2340

2954

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

2341

2955

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

2348

2962

}

2349

2963

2350

2964

/* Cleanup things */

2965

free(mc.interfaces);

2966

2351

2967

if(sb != NULL)

2352

2968

avahi_s_service_browser_free(sb);

2353

2969

2354

2970

if(mc.server != NULL)

2355

2971

avahi_server_free(mc.server);

2356

2972

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2973

if(simple_poll != NULL)

2974

avahi_simple_poll_free(simple_poll);

2359

2975

2360

2976

if(gnutls_initialized){

2361

2977

gnutls_certificate_free_credentials(mc.cred);

2373

2989

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

2374

2990

while(mc.current_server != NULL){

2375

2991

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

2376

3000

free(mc.current_server);

2377

3001

mc.current_server = next;

2378

3002

}

2379

3003

}

2380

3004

2381

/* Re-raise priviliges */

3005

/* Re-raise privileges */

2382

3006

{

2383

raise_privileges();

2384

2385

/* Run network hooks */

2386

run_network_hooks("stop", interfaces_hooks, delay);

2387

2388

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

2389

{

2390

char *interface = NULL;

2391

while((interface=argz_next(interfaces_to_take_down,

2392

interfaces_to_take_down_size,

2393

interface))){

2394

ret_errno = take_down_interface(interface);

2395

if(ret_errno != 0){

2396

errno = ret_errno;

2397

perror_plus("Failed to take down interface");

2398

}

2399

}

2400

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

2401

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

2402

" down\n");

2403

}

2404

}

2405

2406

lower_privileges_permanently();

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

}

2407

3041

}

2408

3042

2409

3043

free(interfaces_to_take_down);

2410

3044

free(interfaces_hooks);

2411

3045

2412

3046

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

2413

if(tempdir_created){

3047

if(tempdir != NULL){

2414

3048

struct dirent **direntries = NULL;

2415

struct dirent *direntry = NULL;

2416

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

2417

alphasort);

2418

if (numentries > 0){

2419

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

2420

direntry = direntries[i];

2421

char *fullname = NULL;

2422

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

2423

direntry->d_name);

2424

if(ret < 0){

2425

perror_plus("asprintf");

2426

continue;

2427

}

2428

ret = remove(fullname);

2429

if(ret == -1){

2430

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

2431

strerror(errno));

2432

}

2433

free(fullname);

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

}

2434

3088

}

2435

}

2436

2437

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

2438

free(direntries);

2439

if (numentries == -1){

2440

perror_plus("scandir");

2441

}

2442

ret = rmdir(tempdir);

2443

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

2444

perror_plus("rmdir");

3089

close(tempdir_fd);

2445

3090

}

2446

3091

}

2447

3092