/mandos/trunk : revision 769

9

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

10

*

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* Everything else is

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13

12

13

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*

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

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#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

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

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stdout, ferror(), remove() */

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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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opendir(), DIR */

56

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

57

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

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inet_pton(), connect() */

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

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inet_pton(), connect(),

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getnameinfo() */

60

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

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61

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

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62

*/

62

63

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

63

64

strtoimax() */

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#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(),

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

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

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

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

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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,

92

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argz_delete(), argz_append(),

93

94

argz_stringify(), argz_add(),

94

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

95

98

96

99

#ifdef __linux__

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100

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

139

142

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

140

143

char *connect_to = NULL;

141

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

142

146

uid_t uid = 65534;

143

147

gid_t gid = 65534;

144

148

145

149

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

146

150

typedef struct server{

147

151

const char *ip;

148

uint16_t port;

152

in_port_t port;

149

153

AvahiIfIndex if_index;

150

154

int af;

151

155

struct timespec last_seen;

155

159

156

160

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

157

161

typedef struct {

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AvahiSimplePoll *simple_poll;

159

162

AvahiServer *server;

160

163

gnutls_certificate_credentials_t cred;

161

164

unsigned int dh_bits;

163

166

const char *priority;

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167

gpgme_ctx_t ctx;

165

168

server *current_server;

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char *interfaces;

170

size_t interfaces_size;

166

171

} mandos_context;

167

172

168

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

169

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

170

.dh_bits = 1024, .priority = "SECURE256"

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

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.current_server = NULL };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

173

175

174

176

sig_atomic_t quit_now = 0;

175

177

int signal_received = 0;

183

185

perror(print_text);

184

186

}

185

187

186

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

188

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

187

189

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

188

190

va_list ap;

189

191

va_start (ap, format);

190

192

191

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

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program_invocation_short_name));

193

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

195

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

194

196

}

195

197

196

198

/*

198

200

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

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* "buffer_length" is how much is already used.

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202

*/

203

__attribute__((nonnull, warn_unused_result))

201

204

size_t incbuffer(char **buffer, size_t buffer_length,

202

205

size_t buffer_capacity){

203

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

204

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

205

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;

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return 0;

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214

}

215

*buffer = new_buf;

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buffer_capacity += BUFFER_SIZE;

209

217

}

210

218

return buffer_capacity;

211

219

}

212

220

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

214

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

215

int af){

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){

216

225

int ret;

217

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

218

227

if(new_server == NULL){

225

234

.af = af };

226

235

if(new_server->ip == NULL){

227

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);

228

252

return false;

229

253

}

230

254

/* Special case of first server */

231

if (mc.current_server == NULL){

255

if(*current_server == NULL){

232

256

new_server->next = new_server;

233

257

new_server->prev = new_server;

234

mc.current_server = new_server;

235

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

258

*current_server = new_server;

236

259

} else {

237

new_server->next = mc.current_server;

238

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;

239

263

new_server->prev->next = new_server;

240

mc.current_server->prev = new_server;

241

}

242

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

243

if(ret == -1){

244

perror_plus("clock_gettime");

245

return false;

264

(*current_server)->prev = new_server;

246

265

}

247

266

return true;

248

267

}

250

269

/*

251

270

* Initialize GPGME.

252

271

*/

253

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

254

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){

255

277

gpgme_error_t rc;

256

278

gpgme_engine_info_t engine_info;

257

279

258

259

280

/*

260

281

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

261

282

*/

262

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

263

284

int ret;

264

285

int fd;

265

286

gpgme_data_t pgp_data;

277

298

return false;

278

299

}

279

300

280

rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

281

302

if(rc != GPG_ERR_NO_ERROR){

282

303

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

283

304

gpgme_strsource(rc), gpgme_strerror(rc));

327

348

}

328

349

329

350

/* Create new GPGME "context" */

330

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

351

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

331

352

if(rc != GPG_ERR_NO_ERROR){

332

353

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

333

354

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

346

367

* Decrypt OpenPGP data.

347

368

* Returns -1 on error

348

369

*/

370

__attribute__((nonnull, warn_unused_result))

349

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

350

372

size_t crypto_size,

351

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

352

375

gpgme_data_t dh_crypto, dh_plain;

353

376

gpgme_error_t rc;

354

377

ssize_t ret;

380

403

381

404

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

382

405

data buffer */

383

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

406

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

384

407

if(rc != GPG_ERR_NO_ERROR){

385

408

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

386

409

gpgme_strsource(rc), gpgme_strerror(rc));

387

410

plaintext_length = -1;

388

411

if(debug){

389

412

gpgme_decrypt_result_t result;

390

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

391

414

if(result == NULL){

392

415

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

393

416

} else {

470

493

return plaintext_length;

471

494

}

472

495

473

static const char * safer_gnutls_strerror(int value){

474

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

475

-Wunreachable-code */

476

if(ret == NULL)

477

ret = "(unknown)";

478

return ret;

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);

479

507

}

480

508

481

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

482

511

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

483

512

const char* string){

484

513

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

485

514

}

486

515

516

__attribute__((nonnull, warn_unused_result))

487

517

static int init_gnutls_global(const char *pubkeyfilename,

488

const char *seckeyfilename){

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

489

521

int ret;

522

unsigned int uret;

490

523

491

524

if(debug){

492

525

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

508

541

}

509

542

510

543

/* OpenPGP credentials */

511

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

512

545

if(ret != GNUTLS_E_SUCCESS){

513

546

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

514

547

safer_gnutls_strerror(ret));

524

557

}

525

558

526

559

ret = gnutls_certificate_set_openpgp_key_file

527

(mc.cred, pubkeyfilename, seckeyfilename,

560

(mc->cred, pubkeyfilename, seckeyfilename,

528

561

GNUTLS_OPENPGP_FMT_BASE64);

529

562

if(ret != GNUTLS_E_SUCCESS){

530

563

fprintf_plus(stderr,

536

569

}

537

570

538

571

/* GnuTLS server initialization */

539

ret = gnutls_dh_params_init(&mc.dh_params);

572

ret = gnutls_dh_params_init(&mc->dh_params);

540

573

if(ret != GNUTLS_E_SUCCESS){

541

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

542

575

" initialization: %s\n",

543

576

safer_gnutls_strerror(ret));

544

577

goto globalfail;

545

578

}

546

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

547

if(ret != GNUTLS_E_SUCCESS){

548

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

549

safer_gnutls_strerror(ret));

550

goto globalfail;

551

}

552

553

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

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);

554

752

555

753

return 0;

556

754

557

755

globalfail:

558

756

559

gnutls_certificate_free_credentials(mc.cred);

757

gnutls_certificate_free_credentials(mc->cred);

560

758

gnutls_global_deinit();

561

gnutls_dh_params_deinit(mc.dh_params);

759

gnutls_dh_params_deinit(mc->dh_params);

562

760

return -1;

563

761

}

564

762

565

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){

566

766

int ret;

567

767

/* GnuTLS session creation */

568

768

do {

580

780

{

581

781

const char *err;

582

782

do {

583

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

783

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

584

784

if(quit_now){

585

785

gnutls_deinit(*session);

586

786

return -1;

597

797

598

798

do {

599

799

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

600

mc.cred);

800

mc->cred);

601

801

if(quit_now){

602

802

gnutls_deinit(*session);

603

803

return -1;

613

813

/* ignore client certificate if any. */

614

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

615

815

616

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

617

618

816

return 0;

619

817

}

620

818

622

820

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

623

821

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

624

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

625

1040

/* Called when a Mandos server is found */

626

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,

627

1043

AvahiIfIndex if_index,

628

int af){

1044

int af, mandos_context *mc){

629

1045

int ret, tcp_sd = -1;

630

1046

ssize_t sret;

631

union {

632

struct sockaddr_in in;

633

struct sockaddr_in6 in6;

634

} to;

1047

struct sockaddr_storage to;

635

1048

char *buffer = NULL;

636

1049

char *decrypted_buffer = NULL;

637

1050

size_t buffer_length = 0;

640

1053

int retval = -1;

641

1054

gnutls_session_t session;

642

1055

int pf; /* Protocol family */

1056

bool route_added = false;

643

1057

644

1058

errno = 0;

645

1059

661

1075

return -1;

662

1076

}

663

1077

664

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);

665

1111

if(ret != 0){

666

1112

return -1;

667

1113

}

668

1114

669

1115

if(debug){

670

1116

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

671

PRIu16 "\n", ip, port);

1117

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

672

1118

}

673

1119

674

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

675

1121

if(tcp_sd < 0){

676

1122

int e = errno;

677

1123

perror_plus("socket");

686

1132

687

1133

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

688

1134

if(af == AF_INET6){

689

to.in6.sin6_family = (sa_family_t)af;

690

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);

691

1137

} else { /* IPv4 */

692

to.in.sin_family = (sa_family_t)af;

693

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);

694

1140

}

695

1141

if(ret < 0 ){

696

1142

int e = errno;

705

1151

goto mandos_end;

706

1152

}

707

1153

if(af == AF_INET6){

708

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

709

-Wconversion and

710

-Wunreachable-code */

711

712

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

713

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

714

-Wunreachable-code*/

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

715

1157

if(if_index == AVAHI_IF_UNSPEC){

716

1158

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

717

1159

" incomplete without a network interface\n");

719

1161

goto mandos_end;

720

1162

}

721

1163

/* Set the network interface number as scope */

722

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

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

723

1165

}

724

1166

} else {

725

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

726

-Wconversion and

727

-Wunreachable-code */

1167

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

728

1168

}

729

1169

730

1170

if(quit_now){

738

1178

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

739

1179

perror_plus("if_indextoname");

740

1180

} else {

741

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

742

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

1181

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

1182

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

743

1183

}

744

1184

} else {

745

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

746

ip, port);

1185

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

1186

ip, (uintmax_t)port);

747

1187

}

748

1188

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

749

1189

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

750

const char *pcret;

751

if(af == AF_INET6){

752

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

753

sizeof(addrstr));

754

} else {

755

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

756

sizeof(addrstr));

757

}

758

if(pcret == NULL){

759

perror_plus("inet_ntop");

760

} else {

761

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

762

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

763

}

764

}

765

}

766

767

if(quit_now){

768

errno = EINTR;

769

goto mandos_end;

770

}

771

772

if(af == AF_INET6){

773

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

774

} else {

775

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

776

}

777

if(ret < 0){

778

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

779

int e = errno;

780

perror_plus("connect");

781

errno = e;

782

}

783

goto mandos_end;

784

}

785

786

if(quit_now){

787

errno = EINTR;

788

goto mandos_end;

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;

789

1270

}

790

1271

791

1272

const char *out = mandos_protocol_version;

942

1423

if(buffer_length > 0){

943

1424

ssize_t decrypted_buffer_size;

944

1425

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

945

&decrypted_buffer);

1426

&decrypted_buffer, mc);

946

1427

if(decrypted_buffer_size >= 0){

947

1428

948

1429

written = 0;

974

1455

975

1456

mandos_end:

976

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

}

977

1464

int e = errno;

978

1465

free(decrypted_buffer);

979

1466

free(buffer);

996

1483

return retval;

997

1484

}

998

1485

1486

__attribute__((nonnull))

999

1487

static void resolve_callback(AvahiSServiceResolver *r,

1000

1488

AvahiIfIndex interface,

1001

1489

AvahiProtocol proto,

1009

1497

AVAHI_GCC_UNUSED AvahiStringList *txt,

1010

1498

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1011

1499

flags,

1012

AVAHI_GCC_UNUSED void* userdata){

1013

assert(r);

1500

void *mc){

1501

if(r == NULL){

1502

return;

1503

}

1014

1504

1015

1505

/* Called whenever a service has been resolved successfully or

1016

1506

timed out */

1017

1507

1018

1508

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1019

1510

return;

1020

1511

}

1021

1512

1025

1516

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

1026

1517

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

1027

1518

domain,

1028

avahi_strerror(avahi_server_errno(mc.server)));

1519

avahi_strerror(avahi_server_errno

1520

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

1029

1521

break;

1030

1522

1031

1523

case AVAHI_RESOLVER_FOUND:

1037

1529

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

1038

1530

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

1039

1531

}

1040

int ret = start_mandos_communication(ip, port, interface,

1041

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);

1042

1536

if(ret == 0){

1043

avahi_simple_poll_quit(mc.simple_poll);

1537

avahi_simple_poll_quit(simple_poll);

1044

1538

} else {

1045

if(not add_server(ip, port, interface,

1046

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)){

1047

1542

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

1048

1543

" list\n", name);

1049

1544

}

1062

1557

const char *domain,

1063

1558

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1064

1559

flags,

1065

AVAHI_GCC_UNUSED void* userdata){

1066

assert(b);

1560

void *mc){

1561

if(b == NULL){

1562

return;

1563

}

1067

1564

1068

1565

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

1069

1566

is removed from the LAN */

1077

1574

case AVAHI_BROWSER_FAILURE:

1078

1575

1079

1576

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

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);

1082

1580

return;

1083

1581

1084

1582

case AVAHI_BROWSER_NEW:

1087

1585

the callback function is called the Avahi server will free the

1088

1586

resolver for us. */

1089

1587

1090

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

1091

name, type, domain, protocol, 0,

1092

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)

1093

1592

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

1094

1593

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1594

avahi_strerror(avahi_server_errno

1595

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

1096

1596

break;

1097

1597

1098

1598

case AVAHI_BROWSER_REMOVE:

1117

1617

signal_received = sig;

1118

1618

int old_errno = errno;

1119

1619

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1620

if(simple_poll != NULL){

1621

avahi_simple_poll_quit(simple_poll);

1122

1622

}

1123

1623

errno = old_errno;

1124

1624

}

1125

1625

1626

__attribute__((nonnull, warn_unused_result))

1126

1627

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

1127

1628

int ret;

1128

1629

error_t ret_errno;

1147

1648

return true;

1148

1649

}

1149

1650

1651

__attribute__((nonnull, warn_unused_result))

1150

1652

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

1151

1653

1152

1654

/* Reject the loopback device */

1194

1696

* corresponds to an acceptable network device.

1195

1697

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

1196

1698

*/

1699

__attribute__((nonnull, warn_unused_result))

1197

1700

int good_interface(const struct dirent *if_entry){

1198

1701

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

1199

1702

return 0;

1217

1720

/*

1218

1721

* This function determines if a network interface is up.

1219

1722

*/

1723

__attribute__((nonnull, warn_unused_result))

1220

1724

bool interface_is_up(const char *interface){

1221

1725

struct ifreq ifr;

1222

1726

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

1233

1737

/*

1234

1738

* This function determines if a network interface is running

1235

1739

*/

1740

__attribute__((nonnull, warn_unused_result))

1236

1741

bool interface_is_running(const char *interface){

1237

1742

struct ifreq ifr;

1238

1743

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

1246

1751

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

1247

1752

}

1248

1753

1754

__attribute__((nonnull, pure, warn_unused_result))

1249

1755

int notdotentries(const struct dirent *direntry){

1250

1756

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

1251

1757

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

1258

1764

}

1259

1765

1260

1766

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

1767

__attribute__((nonnull, warn_unused_result))

1261

1768

int runnable_hook(const struct dirent *direntry){

1262

1769

int ret;

1263

1770

size_t sret;

1271

1778

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

1272

1779

"abcdefghijklmnopqrstuvwxyz"

1273

1780

"0123456789"

1274

"_-");

1781

"_.-");

1275

1782

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

1276

1783

/* Contains non-allowed characters */

1277

1784

if(debug){

1281

1788

return 0;

1282

1789

}

1283

1790

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);

1791

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

1292

1792

if(ret == -1){

1293

1793

if(debug){

1294

1794

perror_plus("Could not stat hook");

1318

1818

return 1;

1319

1819

}

1320

1820

1321

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){

1322

1824

int ret;

1323

1825

struct timespec now;

1324

1826

struct timespec waited_time;

1325

1827

intmax_t block_time;

1326

1828

1327

1829

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1830

if(mc->current_server == NULL){

1831

if(debug){

1330

1832

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

1331

1833

" No timeout!\n");

1332

1834

}

1333

1835

ret = avahi_simple_poll_iterate(s, -1);

1334

1836

} else {

1335

if (debug){

1837

if(debug){

1336

1838

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

1337

1839

" it, or wait\n");

1338

1840

}

1345

1847

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

1346

1848

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

1347

1849

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1850

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

1349

1851

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1852

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

1351

1853

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

1352

1854

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

1353

1855

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

1355

1857

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

1356

1858

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

1357

1859

1358

if (debug){

1860

if(debug){

1359

1861

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

1360

1862

block_time);

1361

1863

}

1362

1864

1363

1865

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);

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);

1368

1870

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1871

avahi_simple_poll_quit(s);

1370

1872

return 0;

1371

1873

}

1372

1874

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1875

&mc->current_server->last_seen);

1374

1876

if(ret == -1){

1375

1877

perror_plus("clock_gettime");

1376

1878

return -1;

1377

1879

}

1378

mc.current_server = mc.current_server->next;

1880

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

1379

1881

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

1380

1882

servers, but don't block */

1381

1883

}

1383

1885

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

1384

1886

}

1385

1887

if(ret != 0){

1386

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

1888

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

1387

1889

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

1388

1890

}

1389

1891

}

1390

1892

}

1391

1893

}

1392

1894

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,

1895

__attribute__((nonnull))

1896

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

1446

1897

const float delay){

1447

struct dirent **direntries;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

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__ */

1452

1926

if(numhooks == -1){

1453

1927

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){

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){

1461

1989

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

}

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1520

1994

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

}

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;

1532

2063

} 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;

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);

1569

2083

}

1570

2084

2085

__attribute__((nonnull, warn_unused_result))

1571

2086

error_t bring_up_interface(const char *const interface,

1572

2087

const float delay){

1573

int sd = -1;

1574

2088

error_t old_errno = errno;

1575

error_t ret_errno = 0;

1576

int ret, ret_setflags;

2089

int ret;

1577

2090

struct ifreq network;

1578

2091

unsigned int if_index = if_nametoindex(interface);

1579

2092

if(if_index == 0){

1588

2101

}

1589

2102

1590

2103

if(not interface_is_up(interface)){

1591

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

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

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

1592

2106

ret_errno = errno;

1593

2107

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

1594

2108

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

2109

errno = old_errno;

1595

2110

return ret_errno;

1596

2111

}

1597

network.ifr_flags |= IFF_UP;

2112

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

1598

2113

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

2114

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

2115

if(sd == -1){

1601

2116

ret_errno = errno;

1602

2117

perror_plus("socket");

1603

2118

errno = old_errno;

1604

2119

return ret_errno;

1605

2120

}

1606

2121

1607

2122

if(quit_now){

1608

close(sd);

2123

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

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

1609

2127

errno = old_errno;

1610

2128

return EINTR;

1611

2129

}

1615

2133

interface);

1616

2134

}

1617

2135

1618

/* Raise priviliges */

1619

raise_privileges();

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

1620

2142

1621

2143

#ifdef __linux__

1622

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1623

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

1624

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

1625

bool restore_loglevel = true;

1626

if(ret_linux == -1){

1627

restore_loglevel = false;

1628

perror_plus("klogctl");

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

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

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

1629

2155

}

1630

2156

#endif /* __linux__ */

1631

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

1632

ret_errno = errno;

2157

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

2158

ioctl_errno = errno;

1633

2159

#ifdef __linux__

1634

2160

if(restore_loglevel){

1635

2161

ret_linux = klogctl(7, NULL, 0);

1639

2165

}

1640

2166

#endif /* __linux__ */

1641

2167

1642

/* Lower privileges */

1643

lower_privileges();

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

1644

2177

1645

2178

/* Close the socket */

1646

2179

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

1649

2182

}

1650

2183

1651

2184

if(ret_setflags == -1){

1652

errno = ret_errno;

2185

errno = ioctl_errno;

1653

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1654

2187

errno = old_errno;

1655

return ret_errno;

2188

return ioctl_errno;

1656

2189

}

1657

2190

} else if(debug){

1658

2191

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

1676

2209

return 0;

1677

2210

}

1678

2211

2212

__attribute__((nonnull, warn_unused_result))

1679

2213

error_t take_down_interface(const char *const interface){

1680

int sd = -1;

1681

2214

error_t old_errno = errno;

1682

error_t ret_errno = 0;

1683

int ret, ret_setflags;

1684

2215

struct ifreq network;

1685

2216

unsigned int if_index = if_nametoindex(interface);

1686

2217

if(if_index == 0){

1689

2220

return ENXIO;

1690

2221

}

1691

2222

if(interface_is_up(interface)){

2223

error_t ret_errno = 0, ioctl_errno = 0;

1692

2224

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

1693

2225

ret_errno = errno;

1694

2226

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

1695

2227

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

2228

errno = old_errno;

1696

2229

return ret_errno;

1697

2230

}

1698

2231

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

1699

2232

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

2233

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

2234

if(sd == -1){

1702

2235

ret_errno = errno;

1703

2236

perror_plus("socket");

1704

2237

errno = old_errno;

1710

2243

interface);

1711

2244

}

1712

2245

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();

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

}

1721

2265

1722

2266

/* Close the socket */

1723

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

2267

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

1724

2268

if(ret == -1){

1725

2269

perror_plus("close");

1726

2270

}

1727

2271

1728

2272

if(ret_setflags == -1){

1729

errno = ret_errno;

2273

errno = ioctl_errno;

1730

2274

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1731

2275

errno = old_errno;

1732

return ret_errno;

2276

return ioctl_errno;

1733

2277

}

1734

2278

} else if(debug){

1735

2279

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

1741

2285

}

1742

2286

1743

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 };

1744

2292

AvahiSServiceBrowser *sb = NULL;

1745

2293

error_t ret_errno;

1746

2294

int ret;

1747

2295

intmax_t tmpmax;

1748

2296

char *tmp;

1749

2297

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

1752

2298

char *interfaces_to_take_down = NULL;

1753

2299

size_t interfaces_to_take_down_size = 0;

1754

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

1755

bool tempdir_created = false;

2300

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

2301

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

2302

char *tempdir = NULL;

1756

2303

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1757

2304

const char *seckey = PATHDIR "/" SECKEY;

1758

2305

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

1759

2307

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

1761

2308

1762

2309

bool gnutls_initialized = false;

1763

2310

bool gpgme_initialized = false;

1815

2362

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

1816

2363

" Diffie-Hellman key exchange",

1817

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 },

1818

2370

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

1819

2371

.arg = "STRING",

1820

2372

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

1854

2406

connect_to = arg;

1855

2407

break;

1856

2408

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

1857

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

1858

(int)',');

2409

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

2410

arg, (int)',');

1859

2411

if(ret_errno != 0){

1860

2412

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

1861

2413

}

1875

2427

}

1876

2428

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

1877

2429

break;

2430

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

2431

dh_params_file = arg;

2432

break;

1878

2433

case 130: /* --priority */

1879

2434

mc.priority = arg;

1880

2435

break;

1936

2491

goto end;

1937

2492

}

1938

2493

}

1939

2494

1940

2495

{

1941

2496

/* Work around Debian bug #633582:

1942

2497

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

1943

2498

1944

/* Re-raise priviliges */

1945

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 {

1946

2505

struct stat st;

1947

2506

1948

2507

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

1965

2524

TEMP_FAILURE_RETRY(close(seckey_fd));

1966

2525

}

1967

2526

}

1968

2527

1969

2528

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

1970

2529

int pubkey_fd = open(pubkey, O_RDONLY);

1971

2530

if(pubkey_fd == -1){

1986

2545

TEMP_FAILURE_RETRY(close(pubkey_fd));

1987

2546

}

1988

2547

}

1989

2548

2549

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

2550

int dhparams_fd = open(dh_params_file, O_RDONLY);

2551

if(dhparams_fd == -1){

2552

perror_plus("open");

2553

} else {

2554

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

2555

if(ret == -1){

2556

perror_plus("fstat");

2557

} else {

2558

if(S_ISREG(st.st_mode)

2559

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

2560

ret = fchown(dhparams_fd, uid, gid);

2561

if(ret == -1){

2562

perror_plus("fchown");

2563

}

2564

}

2565

}

2566

TEMP_FAILURE_RETRY(close(dhparams_fd));

2567

}

2568

}

2569

1990

2570

/* Lower privileges */

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2571

ret_errno = lower_privileges();

2572

if(ret_errno != 0){

2573

errno = ret_errno;

2574

perror_plus("Failed to lower privileges");

1995

2575

}

1996

2576

}

1997

2577

}

1998

2578

1999

/* Remove empty interface names */

2579

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

2000

2580

{

2001

2581

char *interface = NULL;

2002

while((interface = argz_next(interfaces, interfaces_size,

2582

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

2003

2583

interface))){

2004

if(if_nametoindex(interface) == 0){

2005

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

2584

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

2585

and if_nametoindex(interface) == 0){

2586

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

2006

2587

fprintf_plus(stderr, "Not using nonexisting interface"

2007

2588

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

2008

2589

}

2009

argz_delete(&interfaces, &interfaces_size, interface);

2590

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

2010

2591

interface = NULL;

2011

2592

}

2012

2593

}

2014

2595

2015

2596

/* Run network hooks */

2016

2597

{

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

}

2598

if(mc.interfaces != NULL){

2599

interfaces_hooks = malloc(mc.interfaces_size);

2600

if(interfaces_hooks == NULL){

2601

perror_plus("malloc");

2602

goto end;

2603

}

2604

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

2605

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

2606

}

2607

run_network_hooks("start", interfaces_hooks != NULL ?

2608

interfaces_hooks : "", delay);

2028

2609

}

2029

2610

2030

2611

if(not debug){

2035

2616

from the signal handler */

2036

2617

/* Initialize the pseudo-RNG for Avahi */

2037

2618

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

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2619

simple_poll = avahi_simple_poll_new();

2620

if(simple_poll == NULL){

2040

2621

fprintf_plus(stderr,

2041

2622

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

2042

2623

exitcode = EX_UNAVAILABLE;

2107

2688

}

2108

2689

2109

2690

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

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2691

if(mc.interfaces == NULL){

2692

struct dirent **direntries = NULL;

2112

2693

/* Look for any good interfaces */

2113

2694

ret = scandir(sys_class_net, &direntries, good_interface,

2114

2695

alphasort);

2115

2696

if(ret >= 1){

2116

2697

/* Add all found interfaces to interfaces list */

2117

2698

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2699

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

2119

2700

direntries[i]->d_name);

2120

2701

if(ret_errno != 0){

2702

errno = ret_errno;

2121

2703

perror_plus("argz_add");

2704

free(direntries[i]);

2122

2705

continue;

2123

2706

}

2124

2707

if(debug){

2125

2708

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

2126

2709

direntries[i]->d_name);

2127

2710

}

2711

free(direntries[i]);

2128

2712

}

2129

2713

free(direntries);

2130

2714

} else {

2131

free(direntries);

2715

if(ret == 0){

2716

free(direntries);

2717

}

2132

2718

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

2133

2719

exitcode = EXIT_FAILURE;

2134

2720

goto end;

2135

2721

}

2136

2722

}

2137

2723

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)){

2724

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

2725

{

2150

2726

char *interface = NULL;

2151

while((interface = argz_next(interfaces, interfaces_size,

2727

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

2152

2728

interface))){

2729

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

2730

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

2731

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

2732

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

2733

interface);

2734

interface = NULL;

2735

while((interface = argz_next(mc.interfaces,

2736

mc.interfaces_size, interface))){

2737

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

2738

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

2739

interface);

2740

interface = NULL;

2741

}

2742

}

2743

break;

2744

}

2153

2745

bool interface_was_up = interface_is_up(interface);

2154

ret = bring_up_interface(interface, delay);

2746

errno = bring_up_interface(interface, delay);

2155

2747

if(not interface_was_up){

2156

if(ret != 0){

2157

errno = ret;

2158

perror_plus("Failed to bring up interface");

2748

if(errno != 0){

2749

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

2750

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

2159

2751

} else {

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

interface);

2752

errno = argz_add(&interfaces_to_take_down,

2753

&interfaces_to_take_down_size,

2754

interface);

2755

if(errno != 0){

2756

perror_plus("argz_add");

2757

}

2163

2758

}

2164

2759

}

2165

2760

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2169

2761

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

2170

2762

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

2171

2763

}

2172

2764

}

2173

2765

2766

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

2767

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

2768

if(debug){

2769

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

2770

mc.interfaces);

2771

}

2772

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

2773

}

2774

2174

2775

if(quit_now){

2175

2776

goto end;

2176

2777

}

2177

2778

2178

ret = init_gnutls_global(pubkey, seckey);

2779

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

2179

2780

if(ret == -1){

2180

2781

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

2181

2782

exitcode = EX_UNAVAILABLE;

2188

2789

goto end;

2189

2790

}

2190

2791

2191

if(mkdtemp(tempdir) == NULL){

2792

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

2793

tempdir = mkdtemp(run_tempdir);

2794

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

2795

if(debug){

2796

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

2797

run_tempdir, old_tempdir);

2798

}

2799

tempdir = mkdtemp(old_tempdir);

2800

}

2801

if(tempdir == NULL){

2192

2802

perror_plus("mkdtemp");

2193

2803

goto end;

2194

2804

}

2195

tempdir_created = true;

2196

2805

2197

2806

if(quit_now){

2198

2807

goto end;

2199

2808

}

2200

2809

2201

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

2810

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

2202

2811

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

2203

2812

exitcode = EX_UNAVAILABLE;

2204

2813

goto end;

2225

2834

goto end;

2226

2835

}

2227

2836

2228

uint16_t port;

2837

in_port_t port;

2229

2838

errno = 0;

2230

2839

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

2231

2840

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

2232

or tmpmax != (uint16_t)tmpmax){

2841

or tmpmax != (in_port_t)tmpmax){

2233

2842

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

2234

2843

exitcode = EX_USAGE;

2235

2844

goto end;

2236

2845

}

2237

2846

2238

2847

if(quit_now){

2239

2848

goto end;

2240

2849

}

2241

2850

2242

port = (uint16_t)tmpmax;

2851

port = (in_port_t)tmpmax;

2243

2852

*address = '\0';

2244

2853

/* Colon in address indicates IPv6 */

2245

2854

int af;

2261

2870

}

2262

2871

2263

2872

while(not quit_now){

2264

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

2873

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

2874

&mc);

2265

2875

if(quit_now or ret == 0){

2266

2876

break;

2267

2877

}

2269

2879

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

2270

2880

(int)retry_interval);

2271

2881

}

2272

sleep((int)retry_interval);

2882

sleep((unsigned int)retry_interval);

2273

2883

}

2274

2884

2275

if (not quit_now){

2885

if(not quit_now){

2276

2886

exitcode = EXIT_SUCCESS;

2277

2887

}

2278

2888

2293

2903

config.publish_domain = 0;

2294

2904

2295

2905

/* Allocate a new server */

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2906

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2907

&config, NULL, NULL, &ret_errno);

2299

2908

2300

2909

/* Free the Avahi configuration data */

2301

2910

avahi_server_config_free(&config);

2316

2925

/* Create the Avahi service browser */

2317

2926

sb = avahi_s_service_browser_new(mc.server, if_index,

2318

2927

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2319

NULL, 0, browse_callback, NULL);

2928

NULL, 0, browse_callback,

2929

(void *)&mc);

2320

2930

if(sb == NULL){

2321

2931

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

2322

2932

avahi_strerror(avahi_server_errno(mc.server)));

2333

2943

if(debug){

2334

2944

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

2335

2945

}

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2946

2947

ret = avahi_loop_with_timeout(simple_poll,

2948

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

2339

2949

if(debug){

2340

2950

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

2341

2951

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

2348

2958

}

2349

2959

2350

2960

/* Cleanup things */

2961

free(mc.interfaces);

2962

2351

2963

if(sb != NULL)

2352

2964

avahi_s_service_browser_free(sb);

2353

2965

2354

2966

if(mc.server != NULL)

2355

2967

avahi_server_free(mc.server);

2356

2968

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2969

if(simple_poll != NULL)

2970

avahi_simple_poll_free(simple_poll);

2359

2971

2360

2972

if(gnutls_initialized){

2361

2973

gnutls_certificate_free_credentials(mc.cred);

2373

2985

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

2374

2986

while(mc.current_server != NULL){

2375

2987

server *next = mc.current_server->next;

2988

#ifdef __GNUC__

2989

#pragma GCC diagnostic push

2990

#pragma GCC diagnostic ignored "-Wcast-qual"

2991

#endif

2992

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

2993

#ifdef __GNUC__

2994

#pragma GCC diagnostic pop

2995

#endif

2376

2996

free(mc.current_server);

2377

2997

mc.current_server = next;

2378

2998

}

2379

2999

}

2380

3000

2381

/* Re-raise priviliges */

3001

/* Re-raise privileges */

2382

3002

{

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();

3003

ret_errno = raise_privileges();

3004

if(ret_errno != 0){

3005

errno = ret_errno;

3006

perror_plus("Failed to raise privileges");

3007

} else {

3008

3009

/* Run network hooks */

3010

run_network_hooks("stop", interfaces_hooks != NULL ?

3011

interfaces_hooks : "", delay);

3012

3013

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

3014

{

3015

char *interface = NULL;

3016

while((interface=argz_next(interfaces_to_take_down,

3017

interfaces_to_take_down_size,

3018

interface))){

3019

ret_errno = take_down_interface(interface);

3020

if(ret_errno != 0){

3021

errno = ret_errno;

3022

perror_plus("Failed to take down interface");

3023

}

3024

}

3025

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

3026

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

3027

" down\n");

3028

}

3029

}

3030

}

3031

3032

ret_errno = lower_privileges_permanently();

3033

if(ret_errno != 0){

3034

errno = ret_errno;

3035

perror_plus("Failed to lower privileges permanently");

3036

}

2407

3037

}

2408

3038

2409

3039

free(interfaces_to_take_down);

2410

3040

free(interfaces_hooks);

2411

3041

2412

3042

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

2413

if(tempdir_created){

3043

if(tempdir != NULL){

2414

3044

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);

3045

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

3046

| O_NOFOLLOW

3047

| O_DIRECTORY

3048

| O_PATH));

3049

if(tempdir_fd == -1){

3050

perror_plus("open");

3051

} else {

3052

#ifdef __GLIBC__

3053

#if __GLIBC_PREREQ(2, 15)

3054

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

3055

notdotentries, alphasort);

3056

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

3057

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

3058

alphasort);

3059

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

3060

#else /* not __GLIBC__ */

3061

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

3062

alphasort);

3063

#endif /* not __GLIBC__ */

3064

if(numentries >= 0){

3065

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

3066

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

3067

if(ret == -1){

3068

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

3069

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

3070

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

3071

}

3072

free(direntries[i]);

3073

}

3074

3075

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

3076

free(direntries);

3077

if(numentries == -1){

3078

perror_plus("scandir");

3079

}

3080

ret = rmdir(tempdir);

3081

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

3082

perror_plus("rmdir");

3083

}

2434

3084

}

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");

3085

TEMP_FAILURE_RETRY(close(tempdir_fd));

2445

3086

}

2446

3087

}

2447

3088