/mandos/release : revision 237.7.310

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

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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(),

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() */

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61

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

61

62

*/

62

63

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

63

64

strtoimax() */

64

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

65

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

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program_invocation_short_name */

67

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

73

*/

74

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

75

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

76

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

77

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

76

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

77

unlinkat() */

78

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

78

79

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

79

80

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

80

81

argp_state, struct argp,

88

89

#include <sys/wait.h> /* waitpid(), WIFEXITED(),

89

90

WEXITSTATUS(), WTERMSIG() */

90

91

#include <grp.h> /* setgroups() */

92

#include <argz.h> /* argz_add_sep(), argz_next(),

93

argz_delete(), argz_append(),

94

argz_stringify(), argz_add(),

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

91

98

92

99

#ifdef __linux__

93

100

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

135

142

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

136

143

char *connect_to = NULL;

137

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

138

146

uid_t uid = 65534;

139

147

gid_t gid = 65534;

140

148

141

149

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

142

150

typedef struct server{

143

151

const char *ip;

144

uint16_t port;

152

in_port_t port;

145

153

AvahiIfIndex if_index;

146

154

int af;

147

155

struct timespec last_seen;

151

159

152

160

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

153

161

typedef struct {

154

AvahiSimplePoll *simple_poll;

155

162

AvahiServer *server;

156

163

gnutls_certificate_credentials_t cred;

157

164

unsigned int dh_bits;

159

166

const char *priority;

160

167

gpgme_ctx_t ctx;

161

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

162

171

} mandos_context;

163

172

164

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

165

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

166

.dh_bits = 1024, .priority = "SECURE256"

167

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

168

.current_server = NULL };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

169

175

170

176

sig_atomic_t quit_now = 0;

171

177

int signal_received = 0;

179

185

perror(print_text);

180

186

}

181

187

182

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

188

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

183

189

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

184

190

va_list ap;

185

191

va_start (ap, format);

186

192

187

193

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

188

194

program_invocation_short_name));

189

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

195

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

190

196

}

191

197

192

198

/*

194

200

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

195

201

* "buffer_length" is how much is already used.

196

202

*/

203

__attribute__((nonnull, warn_unused_result))

197

204

size_t incbuffer(char **buffer, size_t buffer_length,

198

205

size_t buffer_capacity){

199

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

200

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

201

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;

202

213

return 0;

203

214

}

215

*buffer = new_buf;

204

216

buffer_capacity += BUFFER_SIZE;

205

217

}

206

218

return buffer_capacity;

207

219

}

208

220

209

221

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

210

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

211

int af){

222

__attribute__((nonnull, warn_unused_result))

223

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

224

int af, server **current_server){

212

225

int ret;

213

226

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

214

227

if(new_server == NULL){

221

234

.af = af };

222

235

if(new_server->ip == NULL){

223

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);

224

252

return false;

225

253

}

226

254

/* Special case of first server */

227

if (mc.current_server == NULL){

255

if(*current_server == NULL){

228

256

new_server->next = new_server;

229

257

new_server->prev = new_server;

230

mc.current_server = new_server;

231

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

258

*current_server = new_server;

232

259

} else {

233

new_server->next = mc.current_server;

234

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;

235

263

new_server->prev->next = new_server;

236

mc.current_server->prev = new_server;

237

}

238

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

239

if(ret == -1){

240

perror_plus("clock_gettime");

241

return false;

264

(*current_server)->prev = new_server;

242

265

}

243

266

return true;

244

267

}

246

269

/*

247

270

* Initialize GPGME.

248

271

*/

249

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

250

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){

251

277

gpgme_error_t rc;

252

278

gpgme_engine_info_t engine_info;

253

279

254

255

280

/*

256

281

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

257

282

*/

258

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

259

284

int ret;

260

285

int fd;

261

286

gpgme_data_t pgp_data;

273

298

return false;

274

299

}

275

300

276

rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

277

302

if(rc != GPG_ERR_NO_ERROR){

278

303

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

279

304

gpgme_strsource(rc), gpgme_strerror(rc));

323

348

}

324

349

325

350

/* Create new GPGME "context" */

326

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

351

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

327

352

if(rc != GPG_ERR_NO_ERROR){

328

353

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

329

354

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

342

367

* Decrypt OpenPGP data.

343

368

* Returns -1 on error

344

369

*/

370

__attribute__((nonnull, warn_unused_result))

345

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

346

372

size_t crypto_size,

347

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

348

375

gpgme_data_t dh_crypto, dh_plain;

349

376

gpgme_error_t rc;

350

377

ssize_t ret;

376

403

377

404

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

378

405

data buffer */

379

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

406

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

380

407

if(rc != GPG_ERR_NO_ERROR){

381

408

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

382

409

gpgme_strsource(rc), gpgme_strerror(rc));

383

410

plaintext_length = -1;

384

411

if(debug){

385

412

gpgme_decrypt_result_t result;

386

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

387

414

if(result == NULL){

388

415

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

389

416

} else {

466

493

return plaintext_length;

467

494

}

468

495

469

static const char * safer_gnutls_strerror(int value){

470

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

471

-Wunreachable-code */

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

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){

505

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

475

507

}

476

508

477

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

478

511

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

479

512

const char* string){

480

513

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

481

514

}

482

515

516

__attribute__((nonnull, warn_unused_result))

483

517

static int init_gnutls_global(const char *pubkeyfilename,

484

const char *seckeyfilename){

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

485

521

int ret;

522

unsigned int uret;

486

523

487

524

if(debug){

488

525

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

504

541

}

505

542

506

543

/* OpenPGP credentials */

507

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

508

545

if(ret != GNUTLS_E_SUCCESS){

509

546

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

510

547

safer_gnutls_strerror(ret));

520

557

}

521

558

522

559

ret = gnutls_certificate_set_openpgp_key_file

523

(mc.cred, pubkeyfilename, seckeyfilename,

560

(mc->cred, pubkeyfilename, seckeyfilename,

524

561

GNUTLS_OPENPGP_FMT_BASE64);

525

562

if(ret != GNUTLS_E_SUCCESS){

526

563

fprintf_plus(stderr,

532

569

}

533

570

534

571

/* GnuTLS server initialization */

535

ret = gnutls_dh_params_init(&mc.dh_params);

572

ret = gnutls_dh_params_init(&mc->dh_params);

536

573

if(ret != GNUTLS_E_SUCCESS){

537

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

538

575

" initialization: %s\n",

539

576

safer_gnutls_strerror(ret));

540

577

goto globalfail;

541

578

}

542

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

543

if(ret != GNUTLS_E_SUCCESS){

544

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

545

safer_gnutls_strerror(ret));

546

goto globalfail;

547

}

548

549

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

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);

550

752

551

753

return 0;

552

754

553

755

globalfail:

554

756

555

gnutls_certificate_free_credentials(mc.cred);

757

gnutls_certificate_free_credentials(mc->cred);

556

758

gnutls_global_deinit();

557

gnutls_dh_params_deinit(mc.dh_params);

759

gnutls_dh_params_deinit(mc->dh_params);

558

760

return -1;

559

761

}

560

762

561

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){

562

766

int ret;

563

767

/* GnuTLS session creation */

564

768

do {

576

780

{

577

781

const char *err;

578

782

do {

579

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

783

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

580

784

if(quit_now){

581

785

gnutls_deinit(*session);

582

786

return -1;

593

797

594

798

do {

595

799

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

596

mc.cred);

800

mc->cred);

597

801

if(quit_now){

598

802

gnutls_deinit(*session);

599

803

return -1;

609

813

/* ignore client certificate if any. */

610

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

611

815

612

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

613

614

816

return 0;

615

817

}

616

818

618

820

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

619

821

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

620

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 = (int)TEMP_FAILURE_RETRY(close(devnull));

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

_exit(EX_UNAVAILABLE);

958

}

959

TEMP_FAILURE_RETRY(close(helperdir_fd));

960

#ifdef __GNUC__

961

#pragma GCC diagnostic push

962

#pragma GCC diagnostic ignored "-Wcast-qual"

963

#endif

964

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

965

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

966

interface, debug ? debug_flag : NULL, NULL },

967

environ) == -1){

968

#ifdef __GNUC__

969

#pragma GCC diagnostic pop

970

#endif

971

perror_plus("fexecve");

972

_exit(EXIT_FAILURE);

973

}

974

}

975

if(pid == -1){

976

perror_plus("fork");

977

return false;

978

}

979

int status;

980

pid_t pret = -1;

981

errno = 0;

982

do {

983

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

984

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

985

int errno_raising = 0;

986

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

987

errno_raising = errno;

988

perror_plus("Failed to raise privileges in order to"

989

" kill helper program");

990

}

991

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

992

perror_plus("kill");

993

}

994

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

995

perror_plus("Failed to lower privileges after killing"

996

" helper program");

997

}

998

return false;

999

}

1000

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

1001

if(pret == -1){

1002

perror_plus("waitpid");

1003

return false;

1004

}

1005

if(WIFEXITED(status)){

1006

if(WEXITSTATUS(status) != 0){

1007

fprintf_plus(stderr, "Error: iprouteadddel exited"

1008

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

1009

return false;

1010

}

1011

return true;

1012

}

1013

if(WIFSIGNALED(status)){

1014

fprintf_plus(stderr, "Error: iprouteadddel died by"

1015

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

1016

return false;

1017

}

1018

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

1019

return false;

1020

}

1021

1022

__attribute__((nonnull, warn_unused_result))

1023

static bool add_local_route(const char *address,

1024

AvahiIfIndex if_index){

1025

if(debug){

1026

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

1027

}

1028

return add_delete_local_route(true, address, if_index);

1029

}

1030

1031

__attribute__((nonnull, warn_unused_result))

1032

static bool delete_local_route(const char *address,

1033

AvahiIfIndex if_index){

1034

if(debug){

1035

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

1036

}

1037

return add_delete_local_route(false, address, if_index);

1038

}

1039

621

1040

/* Called when a Mandos server is found */

622

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

1041

__attribute__((nonnull, warn_unused_result))

1042

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

623

1043

AvahiIfIndex if_index,

624

int af){

1044

int af, mandos_context *mc){

625

1045

int ret, tcp_sd = -1;

626

1046

ssize_t sret;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

1047

struct sockaddr_storage to;

631

1048

char *buffer = NULL;

632

1049

char *decrypted_buffer = NULL;

633

1050

size_t buffer_length = 0;

636

1053

int retval = -1;

637

1054

gnutls_session_t session;

638

1055

int pf; /* Protocol family */

1056

bool route_added = false;

639

1057

640

1058

errno = 0;

641

1059

657

1075

return -1;

658

1076

}

659

1077

660

ret = init_gnutls_session(&session);

1078

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

1079

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

1080

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

1081

bool match = false;

1082

{

1083

char *interface = NULL;

1084

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

1085

interface))){

1086

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

1087

match = true;

1088

break;

1089

}

1090

}

1091

}

1092

if(not match){

1093

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

1094

connect to the server */

1095

if(debug){

1096

char interface[IF_NAMESIZE];

1097

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

1098

perror_plus("if_indextoname");

1099

} else {

1100

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

1101

" \"%s\"\n",

1102

if_indextoname((unsigned int)if_index,

1103

interface));

1104

}

1105

}

1106

return -1;

1107

}

1108

}

1109

1110

ret = init_gnutls_session(&session, mc);

661

1111

if(ret != 0){

662

1112

return -1;

663

1113

}

664

1114

665

1115

if(debug){

666

1116

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

667

PRIu16 "\n", ip, port);

1117

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

668

1118

}

669

1119

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

671

1121

if(tcp_sd < 0){

672

1122

int e = errno;

673

1123

perror_plus("socket");

682

1132

683

1133

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

684

1134

if(af == AF_INET6){

685

to.in6.sin6_family = (sa_family_t)af;

686

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

1135

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

1136

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

687

1137

} else { /* IPv4 */

688

to.in.sin_family = (sa_family_t)af;

689

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

1138

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

1139

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

690

1140

}

691

1141

if(ret < 0 ){

692

1142

int e = errno;

701

1151

goto mandos_end;

702

1152

}

703

1153

if(af == AF_INET6){

704

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

705

-Wconversion and

706

-Wunreachable-code */

707

708

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

709

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

710

-Wunreachable-code*/

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

711

1157

if(if_index == AVAHI_IF_UNSPEC){

712

1158

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

713

1159

" incomplete without a network interface\n");

715

1161

goto mandos_end;

716

1162

}

717

1163

/* Set the network interface number as scope */

718

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

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

719

1165

}

720

1166

} else {

721

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

722

-Wconversion and

723

-Wunreachable-code */

1167

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

724

1168

}

725

1169

726

1170

if(quit_now){

734

1178

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

735

1179

perror_plus("if_indextoname");

736

1180

} else {

737

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

738

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

1181

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

1182

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

739

1183

}

740

1184

} else {

741

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

742

ip, port);

1185

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

1186

ip, (uintmax_t)port);

743

1187

}

744

1188

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

745

1189

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

746

const char *pcret;

747

if(af == AF_INET6){

748

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

749

sizeof(addrstr));

750

} else {

751

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

752

sizeof(addrstr));

753

}

754

if(pcret == NULL){

755

perror_plus("inet_ntop");

756

} else {

757

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

758

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

759

}

760

}

761

}

762

763

if(quit_now){

764

errno = EINTR;

765

goto mandos_end;

766

}

767

768

if(af == AF_INET6){

769

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

770

} else {

771

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

772

}

773

if(ret < 0){

774

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

775

int e = errno;

776

perror_plus("connect");

777

errno = e;

778

}

779

goto mandos_end;

780

}

781

782

if(quit_now){

783

errno = EINTR;

784

goto mandos_end;

1190

if(af == AF_INET6){

1191

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

1192

sizeof(struct sockaddr_in6),

1193

addrstr, sizeof(addrstr), NULL, 0,

1194

NI_NUMERICHOST);

1195

} else {

1196

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

1197

sizeof(struct sockaddr_in),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

}

1201

if(ret == EAI_SYSTEM){

1202

perror_plus("getnameinfo");

1203

} else if(ret != 0) {

1204

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

1205

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

1206

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

1207

}

1208

}

1209

1210

if(quit_now){

1211

errno = EINTR;

1212

goto mandos_end;

1213

}

1214

1215

while(true){

1216

if(af == AF_INET6){

1217

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

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

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

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

if(errno == ENETUNREACH

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

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

1234

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

1235

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

1236

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

1237

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

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

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

1241

1242

Avahi bug reference:

1243

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

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

785

1270

}

786

1271

787

1272

const char *out = mandos_protocol_version;

938

1423

if(buffer_length > 0){

939

1424

ssize_t decrypted_buffer_size;

940

1425

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

941

&decrypted_buffer);

1426

&decrypted_buffer, mc);

942

1427

if(decrypted_buffer_size >= 0){

943

1428

944

1429

written = 0;

970

1455

971

1456

mandos_end:

972

1457

{

1458

if(route_added){

1459

if(not delete_local_route(ip, if_index)){

1460

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

1461

" interface %d", ip, if_index);

1462

}

1463

}

973

1464

int e = errno;

974

1465

free(decrypted_buffer);

975

1466

free(buffer);

992

1483

return retval;

993

1484

}

994

1485

1486

__attribute__((nonnull))

995

1487

static void resolve_callback(AvahiSServiceResolver *r,

996

1488

AvahiIfIndex interface,

997

1489

AvahiProtocol proto,

1005

1497

AVAHI_GCC_UNUSED AvahiStringList *txt,

1006

1498

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1007

1499

flags,

1008

AVAHI_GCC_UNUSED void* userdata){

1009

assert(r);

1500

void *mc){

1501

if(r == NULL){

1502

return;

1503

}

1010

1504

1011

1505

/* Called whenever a service has been resolved successfully or

1012

1506

timed out */

1013

1507

1014

1508

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1015

1510

return;

1016

1511

}

1017

1512

1021

1516

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

1022

1517

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

1023

1518

domain,

1024

avahi_strerror(avahi_server_errno(mc.server)));

1519

avahi_strerror(avahi_server_errno

1520

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

1025

1521

break;

1026

1522

1027

1523

case AVAHI_RESOLVER_FOUND:

1033

1529

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

1034

1530

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

1035

1531

}

1036

int ret = start_mandos_communication(ip, port, interface,

1037

avahi_proto_to_af(proto));

1532

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

1533

interface,

1534

avahi_proto_to_af(proto),

1535

mc);

1038

1536

if(ret == 0){

1039

avahi_simple_poll_quit(mc.simple_poll);

1537

avahi_simple_poll_quit(simple_poll);

1040

1538

} else {

1041

if(not add_server(ip, port, interface,

1042

avahi_proto_to_af(proto))){

1539

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

1540

avahi_proto_to_af(proto),

1541

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

1043

1542

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

1044

1543

" list\n", name);

1045

1544

}

1058

1557

const char *domain,

1059

1558

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1060

1559

flags,

1061

AVAHI_GCC_UNUSED void* userdata){

1062

assert(b);

1560

void *mc){

1561

if(b == NULL){

1562

return;

1563

}

1063

1564

1064

1565

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

1065

1566

is removed from the LAN */

1073

1574

case AVAHI_BROWSER_FAILURE:

1074

1575

1075

1576

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

1076

avahi_strerror(avahi_server_errno(mc.server)));

1077

avahi_simple_poll_quit(mc.simple_poll);

1577

avahi_strerror(avahi_server_errno

1578

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

1579

avahi_simple_poll_quit(simple_poll);

1078

1580

return;

1079

1581

1080

1582

case AVAHI_BROWSER_NEW:

1083

1585

the callback function is called the Avahi server will free the

1084

1586

resolver for us. */

1085

1587

1086

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

1087

name, type, domain, protocol, 0,

1088

resolve_callback, NULL) == NULL)

1588

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

1589

interface, protocol, name, type,

1590

domain, protocol, 0,

1591

resolve_callback, mc) == NULL)

1089

1592

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

1090

1593

" %s\n", name,

1091

avahi_strerror(avahi_server_errno(mc.server)));

1594

avahi_strerror(avahi_server_errno

1595

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

1092

1596

break;

1093

1597

1094

1598

case AVAHI_BROWSER_REMOVE:

1113

1617

signal_received = sig;

1114

1618

int old_errno = errno;

1115

1619

/* set main loop to exit */

1116

if(mc.simple_poll != NULL){

1117

avahi_simple_poll_quit(mc.simple_poll);

1620

if(simple_poll != NULL){

1621

avahi_simple_poll_quit(simple_poll);

1118

1622

}

1119

1623

errno = old_errno;

1120

1624

}

1121

1625

1626

__attribute__((nonnull, warn_unused_result))

1122

1627

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

1123

1628

int ret;

1629

error_t ret_errno;

1124

1630

1125

1631

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

1126

1632

if(s < 0){

1633

ret_errno = errno;

1127

1634

perror_plus("socket");

1635

errno = ret_errno;

1128

1636

return false;

1129

1637

}

1130

1638

strcpy(ifr->ifr_name, ifname);

1131

1639

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1132

1640

if(ret == -1){

1133

1641

if(debug){

1642

ret_errno = errno;

1134

1643

perror_plus("ioctl SIOCGIFFLAGS");

1644

errno = ret_errno;

1135

1645

}

1136

1646

return false;

1137

1647

}

1138

1648

return true;

1139

1649

}

1140

1650

1651

__attribute__((nonnull, warn_unused_result))

1141

1652

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

1142

1653

1143

1654

/* Reject the loopback device */

1185

1696

* corresponds to an acceptable network device.

1186

1697

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

1187

1698

*/

1699

__attribute__((nonnull, warn_unused_result))

1188

1700

int good_interface(const struct dirent *if_entry){

1189

1701

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

1190

1702

return 0;

1206

1718

}

1207

1719

1208

1720

/*

1209

* This function determines if a directory entry in /sys/class/net

1210

* corresponds to an acceptable network device which is up.

1211

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

1212

*/

1213

int up_interface(const struct dirent *if_entry){

1214

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

1215

return 0;

1216

}

1217

1218

struct ifreq ifr;

1219

if(not get_flags(if_entry->d_name, &ifr)){

1220

if(debug){

1221

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

1222

"\"%s\"\n", if_entry->d_name);

1223

}

1224

return 0;

1225

}

1226

1227

/* Reject down interfaces */

1228

if(not (ifr.ifr_flags & IFF_UP)){

1229

if(debug){

1230

fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",

1231

if_entry->d_name);

1232

}

1233

return 0;

1234

}

1235

1236

/* Reject non-running interfaces */

1237

if(not (ifr.ifr_flags & IFF_RUNNING)){

1238

if(debug){

1239

fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",

1240

if_entry->d_name);

1241

}

1242

return 0;

1243

}

1244

1245

if(not good_flags(if_entry->d_name, &ifr)){

1246

return 0;

1247

}

1248

return 1;

1249

}

1250

1721

* This function determines if a network interface is up.

1722

*/

1723

__attribute__((nonnull, warn_unused_result))

1724

bool interface_is_up(const char *interface){

1725

struct ifreq ifr;

1726

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

1727

if(debug){

1728

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

1729

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

1730

}

1731

return false;

1732

}

1733

1734

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

1735

}

1736

1737

/*

1738

* This function determines if a network interface is running

1739

*/

1740

__attribute__((nonnull, warn_unused_result))

1741

bool interface_is_running(const char *interface){

1742

struct ifreq ifr;

1743

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

1744

if(debug){

1745

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

1746

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

1747

}

1748

return false;

1749

}

1750

1751

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

1752

}

1753

1754

__attribute__((nonnull, pure, warn_unused_result))

1251

1755

int notdotentries(const struct dirent *direntry){

1252

1756

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

1253

1757

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

1260

1764

}

1261

1765

1262

1766

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

1767

__attribute__((nonnull, warn_unused_result))

1263

1768

int runnable_hook(const struct dirent *direntry){

1264

1769

int ret;

1265

1770

size_t sret;

1273

1778

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

1274

1779

"abcdefghijklmnopqrstuvwxyz"

1275

1780

"0123456789"

1276

"_-");

1781

"_.-");

1277

1782

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

1278

1783

/* Contains non-allowed characters */

1279

1784

if(debug){

1283

1788

return 0;

1284

1789

}

1285

1790

1286

char *fullname = NULL;

1287

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

1288

if(ret < 0){

1289

perror_plus("asprintf");

1290

return 0;

1291

}

1292

1293

ret = stat(fullname, &st);

1791

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

1294

1792

if(ret == -1){

1295

1793

if(debug){

1296

1794

perror_plus("Could not stat hook");

1320

1818

return 1;

1321

1819

}

1322

1820

1323

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1821

__attribute__((nonnull, warn_unused_result))

1822

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1823

mandos_context *mc){

1324

1824

int ret;

1325

1825

struct timespec now;

1326

1826

struct timespec waited_time;

1327

1827

intmax_t block_time;

1328

1828

1329

1829

while(true){

1330

if(mc.current_server == NULL){

1331

if (debug){

1830

if(mc->current_server == NULL){

1831

if(debug){

1332

1832

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

1333

1833

" No timeout!\n");

1334

1834

}

1335

1835

ret = avahi_simple_poll_iterate(s, -1);

1336

1836

} else {

1337

if (debug){

1837

if(debug){

1338

1838

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

1339

1839

" it, or wait\n");

1340

1840

}

1347

1847

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

1348

1848

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

1349

1849

waited_time.tv_sec = (now.tv_sec

1350

- mc.current_server->last_seen.tv_sec);

1850

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

1351

1851

waited_time.tv_nsec = (now.tv_nsec

1352

- mc.current_server->last_seen.tv_nsec);

1852

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

1353

1853

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

1354

1854

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

1355

1855

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

1357

1857

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

1358

1858

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

1359

1859

1360

if (debug){

1860

if(debug){

1361

1861

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

1362

1862

block_time);

1363

1863

}

1364

1864

1365

1865

if(block_time <= 0){

1366

ret = start_mandos_communication(mc.current_server->ip,

1367

mc.current_server->port,

1368

mc.current_server->if_index,

1369

mc.current_server->af);

1866

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

1867

mc->current_server->port,

1868

mc->current_server->if_index,

1869

mc->current_server->af, mc);

1370

1870

if(ret == 0){

1371

avahi_simple_poll_quit(mc.simple_poll);

1871

avahi_simple_poll_quit(s);

1372

1872

return 0;

1373

1873

}

1374

1874

ret = clock_gettime(CLOCK_MONOTONIC,

1375

&mc.current_server->last_seen);

1875

&mc->current_server->last_seen);

1376

1876

if(ret == -1){

1377

1877

perror_plus("clock_gettime");

1378

1878

return -1;

1379

1879

}

1380

mc.current_server = mc.current_server->next;

1880

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

1381

1881

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

1382

1882

servers, but don't block */

1383

1883

}

1385

1885

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

1386

1886

}

1387

1887

if(ret != 0){

1388

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

1888

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

1389

1889

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

1390

1890

}

1391

1891

}

1392

1892

}

1393

1893

}

1394

1894

1395

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

1396

int raise_privileges(void){

1397

int old_errno = errno;

1398

int ret_errno = 0;

1399

errno = 0;

1400

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

1401

perror_plus("seteuid");

1402

}

1403

ret_errno = errno;

1404

errno = old_errno;

1405

return ret_errno;

1406

}

1407

1408

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

1409

int raise_privileges_permanently(void){

1410

int old_errno = errno;

1411

int ret_errno = raise_privileges();

1412

if(ret_errno != 0){

1413

errno = old_errno;

1414

return ret_errno;

1415

}

1416

errno = 0;

1417

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

1418

perror_plus("seteuid");

1419

}

1420

ret_errno = errno;

1421

errno = old_errno;

1422

return ret_errno;

1423

}

1424

1425

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

1426

int lower_privileges(void){

1427

int old_errno = errno;

1428

int ret_errno = 0;

1429

errno = 0;

1430

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

1431

perror_plus("seteuid");

1432

}

1433

ret_errno = errno;

1434

errno = old_errno;

1435

return ret_errno;

1436

}

1437

1438

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

1895

__attribute__((nonnull))

1896

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

1439

1897

const float delay){

1440

struct dirent **direntries;

1441

struct dirent *direntry;

1442

int ret;

1443

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

1444

alphasort);

1898

struct dirent **direntries = NULL;

1899

if(hookdir_fd == -1){

1900

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1901

| O_CLOEXEC);

1902

if(hookdir_fd == -1){

1903

if(errno == ENOENT){

1904

if(debug){

1905

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

1906

" found\n", hookdir);

1907

}

1908

} else {

1909

perror_plus("open");

1910

}

1911

return;

1912

}

1913

}

1914

#ifdef __GLIBC__

1915

#if __GLIBC_PREREQ(2, 15)

1916

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

1917

runnable_hook, alphasort);

1918

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

1919

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

1920

alphasort);

1921

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

1922

#else /* not __GLIBC__ */

1923

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

1924

alphasort);

1925

#endif /* not __GLIBC__ */

1445

1926

if(numhooks == -1){

1446

1927

perror_plus("scandir");

1447

} else {

1448

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

1449

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

1450

direntry = direntries[i];

1451

char *fullname = NULL;

1452

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

1453

if(ret < 0){

1928

return;

1929

}

1930

struct dirent *direntry;

1931

int ret;

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1937

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

1938

direntry = direntries[i];

1939

if(debug){

1940

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

1941

direntry->d_name);

1942

}

1943

pid_t hook_pid = fork();

1944

if(hook_pid == 0){

1945

/* Child */

1946

/* Raise privileges */

1947

errno = raise_privileges_permanently();

1948

if(errno != 0){

1949

perror_plus("Failed to raise privileges");

1950

_exit(EX_NOPERM);

1951

}

1952

/* Set group */

1953

errno = 0;

1954

ret = setgid(0);

1955

if(ret == -1){

1956

perror_plus("setgid");

1957

_exit(EX_NOPERM);

1958

}

1959

/* Reset supplementary groups */

1960

errno = 0;

1961

ret = setgroups(0, NULL);

1962

if(ret == -1){

1963

perror_plus("setgroups");

1964

_exit(EX_NOPERM);

1965

}

1966

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

1967

if(ret == -1){

1968

perror_plus("setenv");

1969

_exit(EX_OSERR);

1970

}

1971

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

1972

if(ret == -1){

1973

perror_plus("setenv");

1974

_exit(EX_OSERR);

1975

}

1976

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

1977

if(ret == -1){

1978

perror_plus("setenv");

1979

_exit(EX_OSERR);

1980

}

1981

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

1982

if(ret == -1){

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

char *delaystring;

1987

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

1988

if(ret == -1){

1454

1989

perror_plus("asprintf");

1455

continue;

1456

}

1457

if(debug){

1458

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

1459

direntry->d_name);

1460

}

1461

pid_t hook_pid = fork();

1462

if(hook_pid == 0){

1463

/* Child */

1464

/* Raise privileges */

1465

raise_privileges_permanently();

1466

/* Set group */

1467

errno = 0;

1468

ret = setgid(0);

1469

if(ret == -1){

1470

perror_plus("setgid");

1471

}

1472

/* Reset supplementary groups */

1473

errno = 0;

1474

ret = setgroups(0, NULL);

1475

if(ret == -1){

1476

perror_plus("setgroups");

1477

}

1478

dup2(devnull, STDIN_FILENO);

1479

close(devnull);

1480

dup2(STDERR_FILENO, STDOUT_FILENO);

1481

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

1482

if(ret == -1){

1483

perror_plus("setenv");

1484

_exit(EX_OSERR);

1485

}

1486

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

1487

if(ret == -1){

1488

perror_plus("setenv");

1489

_exit(EX_OSERR);

1490

}

1491

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

1492

if(ret == -1){

1493

perror_plus("setenv");

1494

_exit(EX_OSERR);

1495

}

1496

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

1497

if(ret == -1){

1498

perror_plus("setenv");

1499

_exit(EX_OSERR);

1500

}

1501

char *delaystring;

1502

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

1503

if(ret == -1){

1504

perror_plus("asprintf");

1505

_exit(EX_OSERR);

1506

}

1507

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

1508

if(ret == -1){

1509

free(delaystring);

1510

perror_plus("setenv");

1511

_exit(EX_OSERR);

1512

}

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1513

1994

free(delaystring);

1514

if(connect_to != NULL){

1515

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

1516

if(ret == -1){

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1520

}

1521

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

1522

perror_plus("execl");

1523

_exit(EXIT_FAILURE);

1524

}

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

free(delaystring);

1999

if(connect_to != NULL){

2000

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

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

}

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

2009

if(hook_fd == -1){

2010

perror_plus("openat");

2011

_exit(EXIT_FAILURE);

2012

}

2013

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

2014

perror_plus("close");

2015

_exit(EXIT_FAILURE);

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

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

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

2032

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

2033

environ) == -1){

2034

perror_plus("fexecve");

2035

_exit(EXIT_FAILURE);

2036

}

2037

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

int status;

2044

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

2045

perror_plus("waitpid");

2046

free(direntry);

2047

continue;

2048

}

2049

if(WIFEXITED(status)){

2050

if(WEXITSTATUS(status) != 0){

2051

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

2052

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

2053

WEXITSTATUS(status));

2054

free(direntry);

2055

continue;

2056

}

2057

} else if(WIFSIGNALED(status)){

2058

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

2059

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

2060

WTERMSIG(status));

2061

free(direntry);

2062

continue;

1525

2063

} else {

1526

int status;

1527

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

1528

perror_plus("waitpid");

1529

free(fullname);

1530

continue;

1531

}

1532

if(WIFEXITED(status)){

1533

if(WEXITSTATUS(status) != 0){

1534

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

1535

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

1536

WEXITSTATUS(status));

1537

free(fullname);

1538

continue;

1539

}

1540

} else if(WIFSIGNALED(status)){

1541

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

1542

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

1543

WTERMSIG(status));

1544

free(fullname);

1545

continue;

1546

} else {

1547

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

1548

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

1549

free(fullname);

1550

continue;

1551

}

1552

}

1553

free(fullname);

1554

if(debug){

1555

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

1556

direntry->d_name);

1557

}

1558

}

1559

close(devnull);

1560

}

1561

return true;

2064

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

2065

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

2066

free(direntry);

2067

continue;

2068

}

2069

}

2070

if(debug){

2071

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

2072

direntry->d_name);

2073

}

2074

free(direntry);

2075

}

2076

free(direntries);

2077

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

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

1562

2083

}

1563

2084

1564

int bring_up_interface(const char * const interface, const float delay){

1565

int sd = -1;

2085

__attribute__((nonnull, warn_unused_result))

2086

error_t bring_up_interface(const char *const interface,

2087

const float delay){

2088

error_t old_errno = errno;

1566

2089

int ret;

1567

2090

struct ifreq network;

1568

AvahiIfIndex if_index = (AvahiIfIndex)if_nametoindex(interface);

2091

unsigned int if_index = if_nametoindex(interface);

1569

2092

if(if_index == 0){

1570

2093

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1571

return EX_UNAVAILABLE;

2094

errno = old_errno;

2095

return ENXIO;

1572

2096

}

1573

2097

1574

2098

if(quit_now){

2099

errno = old_errno;

1575

2100

return EINTR;

1576

2101

}

1577

2102

1578

/* Re-raise priviliges */

1579

raise_privileges();

1580

1581

#ifdef __linux__

1582

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1583

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

1584

ret = klogctl(8, NULL, 5);

1585

bool restore_loglevel = true;

1586

if(ret == -1){

1587

restore_loglevel = false;

1588

perror_plus("klogctl");

1589

}

1590

#endif /* __linux__ */

1591

1592

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1593

if(sd < 0){

1594

perror_plus("socket");

1595

#ifdef __linux__

1596

if(restore_loglevel){

1597

ret = klogctl(7, NULL, 0);

1598

if(ret == -1){

1599

perror_plus("klogctl");

1600

}

1601

}

1602

#endif /* __linux__ */

1603

/* Lower privileges */

1604

lower_privileges();

1605

return EX_OSERR;

1606

;

1607

}

1608

strcpy(network.ifr_name, interface);

1609

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1610

if(ret == -1){

1611

perror_plus("ioctl SIOCGIFFLAGS");

1612

#ifdef __linux__

1613

if(restore_loglevel){

1614

ret = klogctl(7, NULL, 0);

1615

if(ret == -1){

1616

perror_plus("klogctl");

1617

}

1618

}

1619

#endif /* __linux__ */

1620

/* Lower privileges */

1621

lower_privileges();

1622

return EX_OSERR;

1623

}

1624

if((network.ifr_flags & IFF_UP) == 0){

1625

network.ifr_flags |= IFF_UP;

1626

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

2103

if(not interface_is_up(interface)){

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

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

2106

ret_errno = errno;

2107

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

2108

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

2109

errno = old_errno;

2110

return ret_errno;

2111

}

2112

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

2113

2114

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

2115

if(sd == -1){

2116

ret_errno = errno;

2117

perror_plus("socket");

2118

errno = old_errno;

2119

return ret_errno;

2120

}

2121

2122

if(quit_now){

2123

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

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

2127

errno = old_errno;

2128

return EINTR;

2129

}

2130

2131

if(debug){

2132

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

2133

interface);

2134

}

2135

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

2142

2143

#ifdef __linux__

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

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

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

2155

}

2156

#endif /* __linux__ */

2157

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

2158

ioctl_errno = errno;

2159

#ifdef __linux__

2160

if(restore_loglevel){

2161

ret_linux = klogctl(7, NULL, 0);

2162

if(ret_linux == -1){

2163

perror_plus("klogctl");

2164

}

2165

}

2166

#endif /* __linux__ */

2167

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

2177

2178

/* Close the socket */

2179

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

1627

2180

if(ret == -1){

2181

perror_plus("close");

2182

}

2183

2184

if(ret_setflags == -1){

2185

errno = ioctl_errno;

1628

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1629

#ifdef __linux__

1630

if(restore_loglevel){

1631

ret = klogctl(7, NULL, 0);

1632

if(ret == -1){

1633

perror_plus("klogctl");

1634

}

1635

}

1636

#endif /* __linux__ */

1637

/* Lower privileges */

1638

lower_privileges();

1639

return EX_OSERR;

2187

errno = old_errno;

2188

return ioctl_errno;

1640

2189

}

2190

} else if(debug){

2191

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

2192

interface);

1641

2193

}

2194

1642

2195

/* Sleep checking until interface is running.

1643

2196

Check every 0.25s, up to total time of delay */

1644

2197

for(int i=0; i < delay * 4; i++){

1645

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1646

if(ret == -1){

1647

perror_plus("ioctl SIOCGIFFLAGS");

1648

} else if(network.ifr_flags & IFF_RUNNING){

2198

if(interface_is_running(interface)){

1649

2199

break;

1650

2200

}

1651

2201

struct timespec sleeptime = { .tv_nsec = 250000000 };

1654

2204

perror_plus("nanosleep");

1655

2205

}

1656

2206

}

1657

/* Close the socket */

1658

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

1659

if(ret == -1){

1660

perror_plus("close");

2207

2208

errno = old_errno;

2209

return 0;

2210

}

2211

2212

__attribute__((nonnull, warn_unused_result))

2213

error_t take_down_interface(const char *const interface){

2214

error_t old_errno = errno;

2215

struct ifreq network;

2216

unsigned int if_index = if_nametoindex(interface);

2217

if(if_index == 0){

2218

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2219

errno = old_errno;

2220

return ENXIO;

1661

2221

}

1662

#ifdef __linux__

1663

if(restore_loglevel){

1664

/* Restores kernel loglevel to default */

1665

ret = klogctl(7, NULL, 0);

2222

if(interface_is_up(interface)){

2223

error_t ret_errno = 0, ioctl_errno = 0;

2224

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

2225

ret_errno = errno;

2226

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

2227

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

2228

errno = old_errno;

2229

return ret_errno;

2230

}

2231

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

2232

2233

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

2234

if(sd == -1){

2235

ret_errno = errno;

2236

perror_plus("socket");

2237

errno = old_errno;

2238

return ret_errno;

2239

}

2240

2241

if(debug){

2242

fprintf_plus(stderr, "Taking down interface \"%s\"\n",

2243

interface);

2244

}

2245

2246

/* Raise privileges */

2247

ret_errno = raise_privileges();

2248

if(ret_errno != 0){

2249

errno = ret_errno;

2250

perror_plus("Failed to raise privileges");

2251

}

2252

2253

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

2254

ioctl_errno = errno;

2255

2256

/* If raise_privileges() succeeded above */

2257

if(ret_errno == 0){

2258

/* Lower privileges */

2259

ret_errno = lower_privileges();

2260

if(ret_errno != 0){

2261

errno = ret_errno;

2262

perror_plus("Failed to lower privileges");

2263

}

2264

}

2265

2266

/* Close the socket */

2267

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

1666

2268

if(ret == -1){

1667

perror_plus("klogctl");

1668

}

2269

perror_plus("close");

2270

}

2271

2272

if(ret_setflags == -1){

2273

errno = ioctl_errno;

2274

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2275

errno = old_errno;

2276

return ioctl_errno;

2277

}

2278

} else if(debug){

2279

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

2280

interface);

1669

2281

}

1670

#endif /* __linux__ */

1671

/* Lower privileges */

1672

lower_privileges();

1673

return errno;

2282

2283

errno = old_errno;

2284

return 0;

1674

2285

}

1675

2286

1676

2287

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

2288

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

2289

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

2290

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

2291

.interfaces = NULL, .interfaces_size = 0 };

1677

2292

AvahiSServiceBrowser *sb = NULL;

1678

int error;

2293

error_t ret_errno;

1679

2294

int ret;

1680

2295

intmax_t tmpmax;

1681

2296

char *tmp;

1682

2297

int exitcode = EXIT_SUCCESS;

1683

const char *interface = "";

1684

struct ifreq network;

1685

int sd = -1;

1686

bool take_down_interface = false;

1687

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

1688

bool tempdir_created = false;

2298

char *interfaces_to_take_down = NULL;

2299

size_t interfaces_to_take_down_size = 0;

2300

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

2301

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

2302

char *tempdir = NULL;

1689

2303

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1690

2304

const char *seckey = PATHDIR "/" SECKEY;

1691

2305

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

char *interfaces_hooks = NULL;

1692

2308

1693

2309

bool gnutls_initialized = false;

1694

2310

bool gpgme_initialized = false;

1746

2362

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

1747

2363

" Diffie-Hellman key exchange",

1748

2364

.group = 2 },

2365

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

2366

.arg = "FILE",

2367

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

2368

" for the Diffie-Hellman key exchange",

2369

.group = 2 },

1749

2370

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

1750

2371

.arg = "STRING",

1751

2372

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

1785

2406

connect_to = arg;

1786

2407

break;

1787

2408

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

1788

interface = arg;

2409

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

2410

arg, (int)',');

2411

if(ret_errno != 0){

2412

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

2413

}

1789

2414

break;

1790

2415

case 's': /* --seckey */

1791

2416

seckey = arg;

1802

2427

}

1803

2428

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

1804

2429

break;

2430

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

2431

dh_params_file = arg;

2432

break;

1805

2433

case 130: /* --priority */

1806

2434

mc.priority = arg;

1807

2435

break;

1863

2491

goto end;

1864

2492

}

1865

2493

}

1866

2494

1867

2495

{

1868

2496

/* Work around Debian bug #633582:

1869

2497

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

1870

2498

1871

/* Re-raise priviliges */

1872

if(raise_privileges() == 0){

2499

/* Re-raise privileges */

2500

ret_errno = raise_privileges();

2501

if(ret_errno != 0){

2502

errno = ret_errno;

2503

perror_plus("Failed to raise privileges");

2504

} else {

1873

2505

struct stat st;

1874

2506

1875

2507

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

1892

2524

TEMP_FAILURE_RETRY(close(seckey_fd));

1893

2525

}

1894

2526

}

1895

2527

1896

2528

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

1897

2529

int pubkey_fd = open(pubkey, O_RDONLY);

1898

2530

if(pubkey_fd == -1){

1913

2545

TEMP_FAILURE_RETRY(close(pubkey_fd));

1914

2546

}

1915

2547

}

1916

2548

1917

2549

/* Lower privileges */

1918

errno = 0;

1919

ret = seteuid(uid);

1920

if(ret == -1){

1921

perror_plus("seteuid");

2550

ret_errno = lower_privileges();

2551

if(ret_errno != 0){

2552

errno = ret_errno;

2553

perror_plus("Failed to lower privileges");

2554

}

2555

}

2556

}

2557

2558

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

2559

{

2560

char *interface = NULL;

2561

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

2562

interface))){

2563

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

2564

and if_nametoindex(interface) == 0){

2565

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

2566

fprintf_plus(stderr, "Not using nonexisting interface"

2567

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

2568

}

2569

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

2570

interface = NULL;

1922

2571

}

1923

2572

}

1924

2573

}

1925

2574

1926

2575

/* Run network hooks */

1927

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

1928

goto end;

2576

{

2577

if(mc.interfaces != NULL){

2578

interfaces_hooks = malloc(mc.interfaces_size);

2579

if(interfaces_hooks == NULL){

2580

perror_plus("malloc");

2581

goto end;

2582

}

2583

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

2584

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

2585

}

2586

run_network_hooks("start", interfaces_hooks != NULL ?

2587

interfaces_hooks : "", delay);

1929

2588

}

1930

2589

1931

2590

if(not debug){

1932

2591

avahi_set_log_function(empty_log);

1933

2592

}

1934

2593

1935

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

1936

struct dirent **direntries;

1937

/* First look for interfaces that are up */

1938

ret = scandir(sys_class_net, &direntries, up_interface,

1939

alphasort);

1940

if(ret == 0){

1941

/* No up interfaces, look for any good interfaces */

1942

free(direntries);

1943

ret = scandir(sys_class_net, &direntries, good_interface,

1944

alphasort);

1945

}

1946

if(ret >= 1){

1947

/* Pick the first interface returned */

1948

interface = strdup(direntries[0]->d_name);

1949

if(debug){

1950

fprintf_plus(stderr, "Using interface \"%s\"\n", interface);

1951

}

1952

if(interface == NULL){

1953

perror_plus("malloc");

1954

free(direntries);

1955

exitcode = EXIT_FAILURE;

1956

goto end;

1957

}

1958

free(direntries);

1959

} else {

1960

free(direntries);

1961

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

1962

exitcode = EXIT_FAILURE;

1963

goto end;

1964

}

1965

}

1966

1967

2594

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

1968

2595

from the signal handler */

1969

2596

/* Initialize the pseudo-RNG for Avahi */

1970

2597

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

1971

mc.simple_poll = avahi_simple_poll_new();

1972

if(mc.simple_poll == NULL){

2598

simple_poll = avahi_simple_poll_new();

2599

if(simple_poll == NULL){

1973

2600

fprintf_plus(stderr,

1974

2601

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

1975

2602

exitcode = EX_UNAVAILABLE;

2039

2666

}

2040

2667

}

2041

2668

2042

/* If the interface is down, bring it up */

2043

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

2044

ret = bring_up_interface(interface, delay);

2045

if(ret){

2046

errno = ret;

2047

perror_plus("Failed to bring up interface");

2048

}

2669

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

2670

if(mc.interfaces == NULL){

2671

struct dirent **direntries = NULL;

2672

/* Look for any good interfaces */

2673

ret = scandir(sys_class_net, &direntries, good_interface,

2674

alphasort);

2675

if(ret >= 1){

2676

/* Add all found interfaces to interfaces list */

2677

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

2678

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

2679

direntries[i]->d_name);

2680

if(ret_errno != 0){

2681

errno = ret_errno;

2682

perror_plus("argz_add");

2683

free(direntries[i]);

2684

continue;

2685

}

2686

if(debug){

2687

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

2688

direntries[i]->d_name);

2689

}

2690

free(direntries[i]);

2691

}

2692

free(direntries);

2693

} else {

2694

if(ret == 0){

2695

free(direntries);

2696

}

2697

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

2698

exitcode = EXIT_FAILURE;

2699

goto end;

2700

}

2701

}

2702

2703

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

2704

{

2705

char *interface = NULL;

2706

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

2707

interface))){

2708

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

2709

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

2710

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

2711

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

2712

interface);

2713

interface = NULL;

2714

while((interface = argz_next(mc.interfaces,

2715

mc.interfaces_size, interface))){

2716

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

2717

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

2718

interface);

2719

interface = NULL;

2720

}

2721

}

2722

break;

2723

}

2724

bool interface_was_up = interface_is_up(interface);

2725

errno = bring_up_interface(interface, delay);

2726

if(not interface_was_up){

2727

if(errno != 0){

2728

perror_plus("Failed to bring up interface");

2729

} else {

2730

errno = argz_add(&interfaces_to_take_down,

2731

&interfaces_to_take_down_size,

2732

interface);

2733

if(errno != 0){

2734

perror_plus("argz_add");

2735

}

2736

}

2737

}

2738

}

2739

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

2740

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

2741

}

2742

}

2743

2744

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

2745

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

2746

if(debug){

2747

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

2748

mc.interfaces);

2749

}

2750

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

2049

2751

}

2050

2752

2051

2753

if(quit_now){

2052

2754

goto end;

2053

2755

}

2054

2756

2055

ret = init_gnutls_global(pubkey, seckey);

2757

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

2056

2758

if(ret == -1){

2057

2759

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

2058

2760

exitcode = EX_UNAVAILABLE;

2065

2767

goto end;

2066

2768

}

2067

2769

2068

if(mkdtemp(tempdir) == NULL){

2770

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

2771

tempdir = mkdtemp(run_tempdir);

2772

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

2773

if(debug){

2774

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

2775

run_tempdir, old_tempdir);

2776

}

2777

tempdir = mkdtemp(old_tempdir);

2778

}

2779

if(tempdir == NULL){

2069

2780

perror_plus("mkdtemp");

2070

2781

goto end;

2071

2782

}

2072

tempdir_created = true;

2073

2783

2074

2784

if(quit_now){

2075

2785

goto end;

2076

2786

}

2077

2787

2078

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

2788

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

2079

2789

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

2080

2790

exitcode = EX_UNAVAILABLE;

2081

2791

goto end;

2102

2812

goto end;

2103

2813

}

2104

2814

2105

uint16_t port;

2815

in_port_t port;

2106

2816

errno = 0;

2107

2817

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

2108

2818

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

2109

or tmpmax != (uint16_t)tmpmax){

2819

or tmpmax != (in_port_t)tmpmax){

2110

2820

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

2111

2821

exitcode = EX_USAGE;

2112

2822

goto end;

2113

2823

}

2114

2824

2115

2825

if(quit_now){

2116

2826

goto end;

2117

2827

}

2118

2828

2119

port = (uint16_t)tmpmax;

2829

port = (in_port_t)tmpmax;

2120

2830

*address = '\0';

2121

2831

/* Colon in address indicates IPv6 */

2122

2832

int af;

2138

2848

}

2139

2849

2140

2850

while(not quit_now){

2141

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

2851

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

2852

&mc);

2142

2853

if(quit_now or ret == 0){

2143

2854

break;

2144

2855

}

2146

2857

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

2147

2858

(int)retry_interval);

2148

2859

}

2149

sleep((int)retry_interval);

2860

sleep((unsigned int)retry_interval);

2150

2861

}

2151

2862

2152

if (not quit_now){

2863

if(not quit_now){

2153

2864

exitcode = EXIT_SUCCESS;

2154

2865

}

2155

2866

2170

2881

config.publish_domain = 0;

2171

2882

2172

2883

/* Allocate a new server */

2173

mc.server = avahi_server_new(avahi_simple_poll_get

2174

(mc.simple_poll), &config, NULL,

2175

NULL, &error);

2884

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2885

&config, NULL, NULL, &ret_errno);

2176

2886

2177

2887

/* Free the Avahi configuration data */

2178

2888

avahi_server_config_free(&config);

2181

2891

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

2182

2892

if(mc.server == NULL){

2183

2893

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

2184

avahi_strerror(error));

2894

avahi_strerror(ret_errno));

2185

2895

exitcode = EX_UNAVAILABLE;

2186

2896

goto end;

2187

2897

}

2193

2903

/* Create the Avahi service browser */

2194

2904

sb = avahi_s_service_browser_new(mc.server, if_index,

2195

2905

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2196

NULL, 0, browse_callback, NULL);

2906

NULL, 0, browse_callback,

2907

(void *)&mc);

2197

2908

if(sb == NULL){

2198

2909

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

2199

2910

avahi_strerror(avahi_server_errno(mc.server)));

2210

2921

if(debug){

2211

2922

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

2212

2923

}

2213

2214

ret = avahi_loop_with_timeout(mc.simple_poll,

2215

(int)(retry_interval * 1000));

2924

2925

ret = avahi_loop_with_timeout(simple_poll,

2926

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

2216

2927

if(debug){

2217

2928

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

2218

2929

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

2225

2936

}

2226

2937

2227

2938

/* Cleanup things */

2939

free(mc.interfaces);

2940

2228

2941

if(sb != NULL)

2229

2942

avahi_s_service_browser_free(sb);

2230

2943

2231

2944

if(mc.server != NULL)

2232

2945

avahi_server_free(mc.server);

2233

2946

2234

if(mc.simple_poll != NULL)

2235

avahi_simple_poll_free(mc.simple_poll);

2947

if(simple_poll != NULL)

2948

avahi_simple_poll_free(simple_poll);

2236

2949

2237

2950

if(gnutls_initialized){

2238

2951

gnutls_certificate_free_credentials(mc.cred);

2250

2963

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

2251

2964

while(mc.current_server != NULL){

2252

2965

server *next = mc.current_server->next;

2966

#ifdef __GNUC__

2967

#pragma GCC diagnostic push

2968

#pragma GCC diagnostic ignored "-Wcast-qual"

2969

#endif

2970

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

2971

#ifdef __GNUC__

2972

#pragma GCC diagnostic pop

2973

#endif

2253

2974

free(mc.current_server);

2254

2975

mc.current_server = next;

2255

2976

}

2256

2977

}

2257

2978

2258

/* Run network hooks */

2259

run_network_hooks("stop", interface, delay);

2260

2261

/* Re-raise priviliges */

2979

/* Re-raise privileges */

2262

2980

{

2263

raise_privileges();

2981

ret_errno = raise_privileges();

2982

if(ret_errno != 0){

2983

errno = ret_errno;

2984

perror_plus("Failed to raise privileges");

2985

} else {

2986

2987

/* Run network hooks */

2988

run_network_hooks("stop", interfaces_hooks != NULL ?

2989

interfaces_hooks : "", delay);

2990

2991

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

2992

{

2993

char *interface = NULL;

2994

while((interface=argz_next(interfaces_to_take_down,

2995

interfaces_to_take_down_size,

2996

interface))){

2997

ret_errno = take_down_interface(interface);

2998

if(ret_errno != 0){

2999

errno = ret_errno;

3000

perror_plus("Failed to take down interface");

3001

}

3002

}

3003

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

3004

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

3005

" down\n");

3006

}

3007

}

3008

}

2264

3009

2265

/* Take down the network interface */

2266

if(take_down_interface and geteuid() == 0){

2267

ret = ioctl(sd, SIOCGIFFLAGS, &network);

2268

if(ret == -1){

2269

perror_plus("ioctl SIOCGIFFLAGS");

2270

} else if(network.ifr_flags & IFF_UP){

2271

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

2272

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

2273

if(ret == -1){

2274

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2275

}

2276

}

2277

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

2278

if(ret == -1){

2279

perror_plus("close");

2280

}

3010

ret_errno = lower_privileges_permanently();

3011

if(ret_errno != 0){

3012

errno = ret_errno;

3013

perror_plus("Failed to lower privileges permanently");

2281

3014

}

2282

3015

}

2283

/* Lower privileges permanently */

2284

errno = 0;

2285

ret = setuid(uid);

2286

if(ret == -1){

2287

perror_plus("setuid");

2288

}

3016

3017

free(interfaces_to_take_down);

3018

free(interfaces_hooks);

2289

3019

2290

3020

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

2291

if(tempdir_created){

3021

if(tempdir != NULL){

2292

3022

struct dirent **direntries = NULL;

2293

struct dirent *direntry = NULL;

2294

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

2295

alphasort);

2296

if (numentries > 0){

2297

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

2298

direntry = direntries[i];

2299

char *fullname = NULL;

2300

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

2301

direntry->d_name);

2302

if(ret < 0){

2303

perror_plus("asprintf");

2304

continue;

2305

}

2306

ret = remove(fullname);

2307

if(ret == -1){

2308

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

2309

strerror(errno));

2310

}

2311

free(fullname);

3023

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

3024

| O_NOFOLLOW

3025

| O_DIRECTORY

3026

| O_PATH));

3027

if(tempdir_fd == -1){

3028

perror_plus("open");

3029

} else {

3030

#ifdef __GLIBC__

3031

#if __GLIBC_PREREQ(2, 15)

3032

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

3033

notdotentries, alphasort);

3034

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

3035

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

3036

alphasort);

3037

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

3038

#else /* not __GLIBC__ */

3039

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

3040

alphasort);

3041

#endif /* not __GLIBC__ */

3042

if(numentries >= 0){

3043

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

3044

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

3045

if(ret == -1){

3046

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

3047

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

3048

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

3049

}

3050

free(direntries[i]);

3051

}

3052

3053

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

3054

free(direntries);

3055

if(numentries == -1){

3056

perror_plus("scandir");

3057

}

3058

ret = rmdir(tempdir);

3059

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

3060

perror_plus("rmdir");

3061

}

2312

3062

}

2313

}

2314

2315

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

2316

free(direntries);

2317

if (numentries == -1){

2318

perror_plus("scandir");

2319

}

2320

ret = rmdir(tempdir);

2321

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

2322

perror_plus("rmdir");

3063

TEMP_FAILURE_RETRY(close(tempdir_fd));

2323

3064

}

2324

3065

}

2325

3066