/mandos/trunk : revision 589.1.1

9

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

10

*

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* Everything else is

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13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

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42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

44

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

45

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

46

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

55

opendir(), DIR */

56

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

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

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inet_pton(), connect(),

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getnameinfo() */

60

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

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inet_pton(), connect() */

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

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60

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

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61

*/

63

62

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

64

63

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(),

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unlinkat() */

78

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

76

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

77

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

79

78

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

80

79

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

81

80

argp_state, struct argp,

89

88

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

90

89

WEXITSTATUS(), WTERMSIG() */

91

90

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

92

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

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argz_delete(), argz_append(),

94

argz_stringify(), argz_add(),

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

98

91

99

92

#ifdef __linux__

100

93

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

142

135

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

143

136

char *connect_to = NULL;

144

137

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

uid_t uid = 65534;

147

gid_t gid = 65534;

148

138

149

139

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

150

140

typedef struct server{

151

141

const char *ip;

152

in_port_t port;

142

uint16_t port;

153

143

AvahiIfIndex if_index;

154

144

int af;

155

145

struct timespec last_seen;

159

149

160

150

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

161

151

typedef struct {

152

AvahiSimplePoll *simple_poll;

162

153

AvahiServer *server;

163

154

gnutls_certificate_credentials_t cred;

164

155

unsigned int dh_bits;

166

157

const char *priority;

167

158

gpgme_ctx_t ctx;

168

159

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

171

160

} mandos_context;

172

161

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

162

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

163

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

164

.dh_bits = 1024, .priority = "SECURE256"

165

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

166

.current_server = NULL };

175

167

176

168

sig_atomic_t quit_now = 0;

177

169

int signal_received = 0;

185

177

perror(print_text);

186

178

}

187

179

188

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

180

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

189

181

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

190

182

va_list ap;

191

183

va_start (ap, format);

192

184

193

185

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

194

186

program_invocation_short_name));

195

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

187

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

196

188

}

197

189

198

190

/*

200

192

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

201

193

* "buffer_length" is how much is already used.

202

194

*/

203

__attribute__((nonnull, warn_unused_result))

204

195

size_t incbuffer(char **buffer, size_t buffer_length,

205

196

size_t buffer_capacity){

206

197

if(buffer_length + BUFFER_SIZE > buffer_capacity){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

198

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

199

if(buffer == NULL){

213

200

return 0;

214

201

}

215

*buffer = new_buf;

216

202

buffer_capacity += BUFFER_SIZE;

217

203

}

218

204

return buffer_capacity;

219

205

}

220

206

221

207

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

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){

208

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

209

int af){

225

210

int ret;

226

211

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

227

212

if(new_server == NULL){

234

219

.af = af };

235

220

if(new_server->ip == NULL){

236

221

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

222

return false;

253

223

}

254

224

/* Special case of first server */

255

if(*current_server == NULL){

225

if (mc.current_server == NULL){

256

226

new_server->next = new_server;

257

227

new_server->prev = new_server;

258

*current_server = new_server;

228

mc.current_server = new_server;

229

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

259

230

} else {

260

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

261

new_server->next = *current_server;

262

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

231

new_server->next = mc.current_server;

232

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

263

233

new_server->prev->next = new_server;

264

(*current_server)->prev = new_server;

234

mc.current_server->prev = new_server;

235

}

236

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

237

if(ret == -1){

238

perror_plus("clock_gettime");

239

return false;

265

240

}

266

241

return true;

267

242

}

269

244

/*

270

245

* Initialize GPGME.

271

246

*/

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){

247

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

248

const char *tempdir){

277

249

gpgme_error_t rc;

278

250

gpgme_engine_info_t engine_info;

279

251

252

280

253

/*

281

254

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

282

255

*/

283

bool import_key(const char * const filename){

256

bool import_key(const char *filename){

284

257

int ret;

285

258

int fd;

286

259

gpgme_data_t pgp_data;

298

271

return false;

299

272

}

300

273

301

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

274

rc = gpgme_op_import(mc.ctx, pgp_data);

302

275

if(rc != GPG_ERR_NO_ERROR){

303

276

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

304

277

gpgme_strsource(rc), gpgme_strerror(rc));

348

321

}

349

322

350

323

/* Create new GPGME "context" */

351

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

324

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

352

325

if(rc != GPG_ERR_NO_ERROR){

353

326

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

354

327

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

367

340

* Decrypt OpenPGP data.

368

341

* Returns -1 on error

369

342

*/

370

__attribute__((nonnull, warn_unused_result))

371

343

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

344

size_t crypto_size,

373

char **plaintext,

374

mandos_context *mc){

345

char **plaintext){

375

346

gpgme_data_t dh_crypto, dh_plain;

376

347

gpgme_error_t rc;

377

348

ssize_t ret;

403

374

404

375

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

405

376

data buffer */

406

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

377

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

407

378

if(rc != GPG_ERR_NO_ERROR){

408

379

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

409

380

gpgme_strsource(rc), gpgme_strerror(rc));

410

381

plaintext_length = -1;

411

382

if(debug){

412

383

gpgme_decrypt_result_t result;

413

result = gpgme_op_decrypt_result(mc->ctx);

384

result = gpgme_op_decrypt_result(mc.ctx);

414

385

if(result == NULL){

415

386

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

416

387

} else {

493

464

return plaintext_length;

494

465

}

495

466

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);

467

static const char * safer_gnutls_strerror(int value){

468

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

469

-Wunreachable-code */

470

if(ret == NULL)

471

ret = "(unknown)";

472

return ret;

507

473

}

508

474

509

475

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

476

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

512

477

const char* string){

513

478

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

514

479

}

515

480

516

__attribute__((nonnull, warn_unused_result))

517

481

static int init_gnutls_global(const char *pubkeyfilename,

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

482

const char *seckeyfilename){

521

483

int ret;

522

unsigned int uret;

523

484

524

485

if(debug){

525

486

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

541

502

}

542

503

543

504

/* OpenPGP credentials */

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

545

506

if(ret != GNUTLS_E_SUCCESS){

546

507

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

547

508

safer_gnutls_strerror(ret));

557

518

}

558

519

559

520

ret = gnutls_certificate_set_openpgp_key_file

560

(mc->cred, pubkeyfilename, seckeyfilename,

521

(mc.cred, pubkeyfilename, seckeyfilename,

561

522

GNUTLS_OPENPGP_FMT_BASE64);

562

523

if(ret != GNUTLS_E_SUCCESS){

563

524

fprintf_plus(stderr,

569

530

}

570

531

571

532

/* GnuTLS server initialization */

572

ret = gnutls_dh_params_init(&mc->dh_params);

533

ret = gnutls_dh_params_init(&mc.dh_params);

573

534

if(ret != GNUTLS_E_SUCCESS){

574

535

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

575

536

" initialization: %s\n",

576

537

safer_gnutls_strerror(ret));

577

538

goto globalfail;

578

539

}

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);

540

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

541

if(ret != GNUTLS_E_SUCCESS){

542

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

543

safer_gnutls_strerror(ret));

544

goto globalfail;

545

}

546

547

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

752

548

753

549

return 0;

754

550

755

551

globalfail:

756

552

757

gnutls_certificate_free_credentials(mc->cred);

553

gnutls_certificate_free_credentials(mc.cred);

758

554

gnutls_global_deinit();

759

gnutls_dh_params_deinit(mc->dh_params);

555

gnutls_dh_params_deinit(mc.dh_params);

760

556

return -1;

761

557

}

762

558

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

559

static int init_gnutls_session(gnutls_session_t *session){

766

560

int ret;

767

561

/* GnuTLS session creation */

768

562

do {

780

574

{

781

575

const char *err;

782

576

do {

783

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

577

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

784

578

if(quit_now){

785

579

gnutls_deinit(*session);

786

580

return -1;

797

591

798

592

do {

799

593

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

800

mc->cred);

594

mc.cred);

801

595

if(quit_now){

802

596

gnutls_deinit(*session);

803

597

return -1;

813

607

/* ignore client certificate if any. */

814

608

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

609

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

611

816

612

return 0;

817

613

}

818

614

820

616

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

821

617

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

822

618

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

1040

619

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

1042

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

620

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

1043

621

AvahiIfIndex if_index,

1044

int af, mandos_context *mc){

622

int af){

1045

623

int ret, tcp_sd = -1;

1046

624

ssize_t sret;

1047

struct sockaddr_storage to;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

1048

629

char *buffer = NULL;

1049

630

char *decrypted_buffer = NULL;

1050

631

size_t buffer_length = 0;

1053

634

int retval = -1;

1054

635

gnutls_session_t session;

1055

636

int pf; /* Protocol family */

1056

bool route_added = false;

1057

637

1058

638

errno = 0;

1059

639

1075

655

return -1;

1076

656

}

1077

657

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);

658

ret = init_gnutls_session(&session);

1111

659

if(ret != 0){

1112

660

return -1;

1113

661

}

1114

662

1115

663

if(debug){

1116

664

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

1117

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

665

PRIu16 "\n", ip, port);

1118

666

}

1119

667

1120

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

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

669

if(tcp_sd < 0){

1122

670

int e = errno;

1123

671

perror_plus("socket");

1132

680

1133

681

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

1134

682

if(af == AF_INET6){

1135

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

1136

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

683

to.in6.sin6_family = (sa_family_t)af;

684

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

1137

685

} else { /* IPv4 */

1138

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

1139

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

686

to.in.sin_family = (sa_family_t)af;

687

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

1140

688

}

1141

689

if(ret < 0 ){

1142

690

int e = errno;

1151

699

goto mandos_end;

1152

700

}

1153

701

if(af == AF_INET6){

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

702

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

703

-Wconversion and

704

-Wunreachable-code */

705

706

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

707

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

708

-Wunreachable-code*/

1157

709

if(if_index == AVAHI_IF_UNSPEC){

1158

710

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

1159

711

" incomplete without a network interface\n");

1161

713

goto mandos_end;

1162

714

}

1163

715

/* Set the network interface number as scope */

1164

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

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

717

}

1166

718

} else {

1167

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

719

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

720

-Wconversion and

721

-Wunreachable-code */

1168

722

}

1169

723

1170

724

if(quit_now){

1178

732

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

1179

733

perror_plus("if_indextoname");

1180

734

} else {

1181

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

1182

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

735

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

736

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

1183

737

}

1184

738

} else {

1185

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

1186

ip, (uintmax_t)port);

739

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

740

ip, port);

1187

741

}

1188

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1189

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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;

744

const char *pcret;

745

if(af == AF_INET6){

746

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

747

sizeof(addrstr));

748

} else {

749

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

750

sizeof(addrstr));

751

}

752

if(pcret == NULL){

753

perror_plus("inet_ntop");

754

} else {

755

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

756

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

757

}

758

}

759

}

760

761

if(quit_now){

762

errno = EINTR;

763

goto mandos_end;

764

}

765

766

if(af == AF_INET6){

767

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

768

} else {

769

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

770

}

771

if(ret < 0){

772

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

773

int e = errno;

774

perror_plus("connect");

775

errno = e;

776

}

777

goto mandos_end;

778

}

779

780

if(quit_now){

781

errno = EINTR;

782

goto mandos_end;

1270

783

}

1271

784

1272

785

const char *out = mandos_protocol_version;

1423

936

if(buffer_length > 0){

1424

937

ssize_t decrypted_buffer_size;

1425

938

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1426

&decrypted_buffer, mc);

939

&decrypted_buffer);

1427

940

if(decrypted_buffer_size >= 0){

1428

941

1429

942

written = 0;

1455

968

1456

969

mandos_end:

1457

970

{

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

}

1464

971

int e = errno;

1465

972

free(decrypted_buffer);

1466

973

free(buffer);

1483

990

return retval;

1484

991

}

1485

992

1486

__attribute__((nonnull))

1487

993

static void resolve_callback(AvahiSServiceResolver *r,

1488

994

AvahiIfIndex interface,

1489

995

AvahiProtocol proto,

1497

1003

AVAHI_GCC_UNUSED AvahiStringList *txt,

1498

1004

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1499

1005

flags,

1500

void *mc){

1501

if(r == NULL){

1502

return;

1503

}

1006

AVAHI_GCC_UNUSED void* userdata){

1007

assert(r);

1504

1008

1505

1009

/* Called whenever a service has been resolved successfully or

1506

1010

timed out */

1507

1011

1508

1012

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1510

1013

return;

1511

1014

}

1512

1015

1516

1019

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

1517

1020

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

1518

1021

domain,

1519

avahi_strerror(avahi_server_errno

1520

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

1022

avahi_strerror(avahi_server_errno(mc.server)));

1521

1023

break;

1522

1024

1523

1025

case AVAHI_RESOLVER_FOUND:

1529

1031

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

1530

1032

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

1531

1033

}

1532

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

1533

interface,

1534

avahi_proto_to_af(proto),

1535

mc);

1034

int ret = start_mandos_communication(ip, port, interface,

1035

avahi_proto_to_af(proto));

1536

1036

if(ret == 0){

1537

avahi_simple_poll_quit(simple_poll);

1037

avahi_simple_poll_quit(mc.simple_poll);

1538

1038

} else {

1539

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

1540

avahi_proto_to_af(proto),

1541

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

1039

if(not add_server(ip, port, interface,

1040

avahi_proto_to_af(proto))){

1542

1041

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

1543

1042

" list\n", name);

1544

1043

}

1557

1056

const char *domain,

1558

1057

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1559

1058

flags,

1560

void *mc){

1561

if(b == NULL){

1562

return;

1563

}

1059

AVAHI_GCC_UNUSED void* userdata){

1060

assert(b);

1564

1061

1565

1062

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

1566

1063

is removed from the LAN */

1574

1071

case AVAHI_BROWSER_FAILURE:

1575

1072

1576

1073

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

1577

avahi_strerror(avahi_server_errno

1578

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

1579

avahi_simple_poll_quit(simple_poll);

1074

avahi_strerror(avahi_server_errno(mc.server)));

1075

avahi_simple_poll_quit(mc.simple_poll);

1580

1076

return;

1581

1077

1582

1078

case AVAHI_BROWSER_NEW:

1585

1081

the callback function is called the Avahi server will free the

1586

1082

resolver for us. */

1587

1083

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)

1084

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

1085

name, type, domain, protocol, 0,

1086

resolve_callback, NULL) == NULL)

1592

1087

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

1593

1088

" %s\n", name,

1594

avahi_strerror(avahi_server_errno

1595

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

1089

avahi_strerror(avahi_server_errno(mc.server)));

1596

1090

break;

1597

1091

1598

1092

case AVAHI_BROWSER_REMOVE:

1617

1111

signal_received = sig;

1618

1112

int old_errno = errno;

1619

1113

/* set main loop to exit */

1620

if(simple_poll != NULL){

1621

avahi_simple_poll_quit(simple_poll);

1114

if(mc.simple_poll != NULL){

1115

avahi_simple_poll_quit(mc.simple_poll);

1622

1116

}

1623

1117

errno = old_errno;

1624

1118

}

1625

1119

1626

__attribute__((nonnull, warn_unused_result))

1627

1120

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

1628

1121

int ret;

1629

error_t ret_errno;

1630

1122

1631

1123

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

1632

1124

if(s < 0){

1633

ret_errno = errno;

1634

1125

perror_plus("socket");

1635

errno = ret_errno;

1636

1126

return false;

1637

1127

}

1638

1128

strcpy(ifr->ifr_name, ifname);

1639

1129

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1640

1130

if(ret == -1){

1641

1131

if(debug){

1642

ret_errno = errno;

1643

1132

perror_plus("ioctl SIOCGIFFLAGS");

1644

errno = ret_errno;

1645

1133

}

1646

1134

return false;

1647

1135

}

1648

1136

return true;

1649

1137

}

1650

1138

1651

__attribute__((nonnull, warn_unused_result))

1652

1139

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

1653

1140

1654

1141

/* Reject the loopback device */

1696

1183

* corresponds to an acceptable network device.

1697

1184

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

1698

1185

*/

1699

__attribute__((nonnull, warn_unused_result))

1700

1186

int good_interface(const struct dirent *if_entry){

1701

1187

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

1702

1188

return 0;

1718

1204

}

1719

1205

1720

1206

/*

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))

1207

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

1208

* corresponds to an acceptable network device which is up.

1209

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

1210

*/

1211

int up_interface(const struct dirent *if_entry){

1212

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

1213

return 0;

1214

}

1215

1216

struct ifreq ifr;

1217

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

1218

if(debug){

1219

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

1220

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

1221

}

1222

return 0;

1223

}

1224

1225

/* Reject down interfaces */

1226

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

1227

if(debug){

1228

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

1229

if_entry->d_name);

1230

}

1231

return 0;

1232

}

1233

1234

/* Reject non-running interfaces */

1235

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

1236

if(debug){

1237

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

1238

if_entry->d_name);

1239

}

1240

return 0;

1241

}

1242

1243

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

1244

return 0;

1245

}

1246

return 1;

1247

}

1248

1755

1249

int notdotentries(const struct dirent *direntry){

1756

1250

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

1757

1251

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

1764

1258

}

1765

1259

1766

1260

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

1767

__attribute__((nonnull, warn_unused_result))

1768

1261

int runnable_hook(const struct dirent *direntry){

1769

1262

int ret;

1770

1263

size_t sret;

1778

1271

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

1779

1272

"abcdefghijklmnopqrstuvwxyz"

1780

1273

"0123456789"

1781

"_.-");

1274

"_-");

1782

1275

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

1783

1276

/* Contains non-allowed characters */

1784

1277

if(debug){

1788

1281

return 0;

1789

1282

}

1790

1283

1791

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

1284

char *fullname = NULL;

1285

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

1286

if(ret < 0){

1287

perror_plus("asprintf");

1288

return 0;

1289

}

1290

1291

ret = stat(fullname, &st);

1792

1292

if(ret == -1){

1793

1293

if(debug){

1794

1294

perror_plus("Could not stat hook");

1818

1318

return 1;

1819

1319

}

1820

1320

1821

__attribute__((nonnull, warn_unused_result))

1822

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1823

mandos_context *mc){

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1824

1322

int ret;

1825

1323

struct timespec now;

1826

1324

struct timespec waited_time;

1827

1325

intmax_t block_time;

1828

1326

1829

1327

while(true){

1830

if(mc->current_server == NULL){

1831

if(debug){

1328

if(mc.current_server == NULL){

1329

if (debug){

1832

1330

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

1833

1331

" No timeout!\n");

1834

1332

}

1835

1333

ret = avahi_simple_poll_iterate(s, -1);

1836

1334

} else {

1837

if(debug){

1335

if (debug){

1838

1336

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

1839

1337

" it, or wait\n");

1840

1338

}

1847

1345

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

1848

1346

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

1849

1347

waited_time.tv_sec = (now.tv_sec

1850

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

1348

- mc.current_server->last_seen.tv_sec);

1851

1349

waited_time.tv_nsec = (now.tv_nsec

1852

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

1350

- mc.current_server->last_seen.tv_nsec);

1853

1351

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

1854

1352

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

1855

1353

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

1857

1355

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

1858

1356

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

1859

1357

1860

if(debug){

1358

if (debug){

1861

1359

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

1862

1360

block_time);

1863

1361

}

1864

1362

1865

1363

if(block_time <= 0){

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);

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);

1870

1368

if(ret == 0){

1871

avahi_simple_poll_quit(s);

1369

avahi_simple_poll_quit(mc.simple_poll);

1872

1370

return 0;

1873

1371

}

1874

1372

ret = clock_gettime(CLOCK_MONOTONIC,

1875

&mc->current_server->last_seen);

1373

&mc.current_server->last_seen);

1876

1374

if(ret == -1){

1877

1375

perror_plus("clock_gettime");

1878

1376

return -1;

1879

1377

}

1880

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

1378

mc.current_server = mc.current_server->next;

1881

1379

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

1882

1380

servers, but don't block */

1883

1381

}

1885

1383

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

1886

1384

}

1887

1385

if(ret != 0){

1888

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

1386

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

1889

1387

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

1890

1388

}

1891

1389

}

1892

1390

}

1893

1391

}

1894

1392

1895

__attribute__((nonnull))

1896

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

1393

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

1897

1394

const float delay){

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__ */

1395

struct dirent **direntries;

1396

struct dirent *direntry;

1397

int ret;

1398

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

1399

alphasort);

1926

1400

if(numhooks == -1){

1927

1401

perror_plus("scandir");

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){

1402

} else {

1403

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

1404

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

1405

direntry = direntries[i];

1406

char *fullname = NULL;

1407

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

1408

if(ret < 0){

1989

1409

perror_plus("asprintf");

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1410

continue;

1411

}

1412

if(debug){

1413

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

1414

direntry->d_name);

1415

}

1416

pid_t hook_pid = fork();

1417

if(hook_pid == 0){

1418

/* Child */

1419

/* Raise privileges */

1420

errno = 0;

1421

ret = seteuid(0);

1422

if(ret == -1){

1423

perror_plus("seteuid");

1424

}

1425

/* Raise privileges even more */

1426

errno = 0;

1427

ret = setuid(0);

1428

if(ret == -1){

1429

perror_plus("setuid");

1430

}

1431

/* Set group */

1432

errno = 0;

1433

ret = setgid(0);

1434

if(ret == -1){

1435

perror_plus("setgid");

1436

}

1437

/* Reset supplementary groups */

1438

errno = 0;

1439

ret = setgroups(0, NULL);

1440

if(ret == -1){

1441

perror_plus("setgroups");

1442

}

1443

dup2(devnull, STDIN_FILENO);

1444

close(devnull);

1445

dup2(STDERR_FILENO, STDOUT_FILENO);

1446

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

1447

if(ret == -1){

1448

perror_plus("setenv");

1449

_exit(EX_OSERR);

1450

}

1451

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

1452

if(ret == -1){

1453

perror_plus("setenv");

1454

_exit(EX_OSERR);

1455

}

1456

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

1457

if(ret == -1){

1458

perror_plus("setenv");

1459

_exit(EX_OSERR);

1460

}

1461

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

1462

if(ret == -1){

1463

perror_plus("setenv");

1464

_exit(EX_OSERR);

1465

}

1466

char *delaystring;

1467

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

1468

if(ret == -1){

1469

perror_plus("asprintf");

1470

_exit(EX_OSERR);

1471

}

1472

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

1473

if(ret == -1){

1474

free(delaystring);

1475

perror_plus("setenv");

1476

_exit(EX_OSERR);

1477

}

1994

1478

free(delaystring);

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;

2063

} else {

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);

2083

}

2084

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;

2089

int ret;

2090

struct ifreq network;

2091

unsigned int if_index = if_nametoindex(interface);

2092

if(if_index == 0){

2093

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

2094

errno = old_errno;

2095

return ENXIO;

2096

}

2097

2098

if(quit_now){

2099

errno = old_errno;

2100

return EINTR;

2101

}

2102

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));

2180

if(ret == -1){

2181

perror_plus("close");

2182

}

2183

2184

if(ret_setflags == -1){

2185

errno = ioctl_errno;

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2187

errno = old_errno;

2188

return ioctl_errno;

2189

}

2190

} else if(debug){

2191

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

2192

interface);

2193

}

2194

2195

/* Sleep checking until interface is running.

2196

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

2197

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

2198

if(interface_is_running(interface)){

2199

break;

2200

}

2201

struct timespec sleeptime = { .tv_nsec = 250000000 };

2202

ret = nanosleep(&sleeptime, NULL);

2203

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

2204

perror_plus("nanosleep");

2205

}

2206

}

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;

2221

}

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));

2268

if(ret == -1){

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);

2281

}

2282

2283

errno = old_errno;

2284

return 0;

1479

if(connect_to != NULL){

1480

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

1481

if(ret == -1){

1482

perror_plus("setenv");

1483

_exit(EX_OSERR);

1484

}

1485

}

1486

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

1487

perror_plus("execl");

1488

_exit(EXIT_FAILURE);

1489

}

1490

} else {

1491

int status;

1492

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

1493

perror_plus("waitpid");

1494

free(fullname);

1495

continue;

1496

}

1497

if(WIFEXITED(status)){

1498

if(WEXITSTATUS(status) != 0){

1499

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

1500

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

1501

WEXITSTATUS(status));

1502

free(fullname);

1503

continue;

1504

}

1505

} else if(WIFSIGNALED(status)){

1506

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

1507

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

1508

WTERMSIG(status));

1509

free(fullname);

1510

continue;

1511

} else {

1512

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

1513

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

1514

free(fullname);

1515

continue;

1516

}

1517

}

1518

free(fullname);

1519

if(debug){

1520

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

1521

direntry->d_name);

1522

}

1523

}

1524

close(devnull);

1525

}

1526

return true;

2285

1527

}

2286

1528

2287

1529

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 };

2292

1530

AvahiSServiceBrowser *sb = NULL;

2293

error_t ret_errno;

1531

int error;

2294

1532

int ret;

2295

1533

intmax_t tmpmax;

2296

1534

char *tmp;

2297

1535

int exitcode = EXIT_SUCCESS;

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;

1536

const char *interface = "";

1537

struct ifreq network;

1538

int sd = -1;

1539

bool take_down_interface = false;

1540

uid_t uid;

1541

gid_t gid;

1542

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

1543

bool tempdir_created = false;

2303

1544

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2304

1545

const char *seckey = PATHDIR "/" SECKEY;

2305

1546

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

char *interfaces_hooks = NULL;

2308

1547

2309

1548

bool gnutls_initialized = false;

2310

1549

bool gpgme_initialized = false;

2362

1601

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

2363

1602

" Diffie-Hellman key exchange",

2364

1603

.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 },

2370

1604

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

2371

1605

.arg = "STRING",

2372

1606

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

2406

1640

connect_to = arg;

2407

1641

break;

2408

1642

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

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

}

1643

interface = arg;

2414

1644

break;

2415

1645

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

2416

1646

seckey = arg;

2427

1657

}

2428

1658

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

2429

1659

break;

2430

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

2431

dh_params_file = arg;

2432

break;

2433

1660

case 130: /* --priority */

2434

1661

mc.priority = arg;

2435

1662

break;

2491

1718

goto end;

2492

1719

}

2493

1720

}

2494

1721

2495

1722

{

2496

1723

/* Work around Debian bug #633582:

2497

1724

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

2498

1725

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");

1726

/* Re-raise priviliges */

1727

errno = 0;

1728

ret = seteuid(0);

1729

if(ret == -1){

1730

perror_plus("seteuid");

2504

1731

} else {

2505

1732

struct stat st;

2506

1733

2524

1751

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

1752

}

2526

1753

}

2527

1754

2528

1755

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

2529

1756

int pubkey_fd = open(pubkey, O_RDONLY);

2530

1757

if(pubkey_fd == -1){

2545

1772

TEMP_FAILURE_RETRY(close(pubkey_fd));

2546

1773

}

2547

1774

}

2548

1775

2549

1776

/* Lower privileges */

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;

1777

errno = 0;

1778

ret = seteuid(uid);

1779

if(ret == -1){

1780

perror_plus("seteuid");

2571

1781

}

2572

1782

}

2573

1783

}

2574

1784

2575

1785

/* Run network hooks */

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);

1786

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

1787

goto end;

2588

1788

}

2589

1789

2590

1790

if(not debug){

2591

1791

avahi_set_log_function(empty_log);

2592

1792

}

2593

1793

1794

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

1795

struct dirent **direntries;

1796

/* First look for interfaces that are up */

1797

ret = scandir(sys_class_net, &direntries, up_interface,

1798

alphasort);

1799

if(ret == 0){

1800

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

1801

free(direntries);

1802

ret = scandir(sys_class_net, &direntries, good_interface,

1803

alphasort);

1804

}

1805

if(ret >= 1){

1806

/* Pick the first interface returned */

1807

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

1808

if(debug){

1809

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

1810

}

1811

if(interface == NULL){

1812

perror_plus("malloc");

1813

free(direntries);

1814

exitcode = EXIT_FAILURE;

1815

goto end;

1816

}

1817

free(direntries);

1818

} else {

1819

free(direntries);

1820

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

1821

exitcode = EXIT_FAILURE;

1822

goto end;

1823

}

1824

}

1825

2594

1826

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

2595

1827

from the signal handler */

2596

1828

/* Initialize the pseudo-RNG for Avahi */

2597

1829

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

2598

simple_poll = avahi_simple_poll_new();

2599

if(simple_poll == NULL){

1830

mc.simple_poll = avahi_simple_poll_new();

1831

if(mc.simple_poll == NULL){

2600

1832

fprintf_plus(stderr,

2601

1833

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

2602

1834

exitcode = EX_UNAVAILABLE;

2666

1898

}

2667

1899

}

2668

1900

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;

1901

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

1902

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

1903

if_index = (AvahiIfIndex) if_nametoindex(interface);

1904

if(if_index == 0){

1905

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

1906

exitcode = EX_UNAVAILABLE;

1907

goto end;

1908

}

1909

1910

if(quit_now){

1911

goto end;

1912

}

1913

1914

/* Re-raise priviliges */

1915

errno = 0;

1916

ret = seteuid(0);

1917

if(ret == -1){

1918

perror_plus("seteuid");

1919

}

1920

1921

#ifdef __linux__

1922

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1923

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

1924

ret = klogctl(8, NULL, 5);

1925

bool restore_loglevel = true;

1926

if(ret == -1){

1927

restore_loglevel = false;

1928

perror_plus("klogctl");

1929

}

1930

#endif /* __linux__ */

1931

1932

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1933

if(sd < 0){

1934

perror_plus("socket");

1935

exitcode = EX_OSERR;

1936

#ifdef __linux__

1937

if(restore_loglevel){

1938

ret = klogctl(7, NULL, 0);

1939

if(ret == -1){

1940

perror_plus("klogctl");

1941

}

1942

}

1943

#endif /* __linux__ */

1944

/* Lower privileges */

1945

errno = 0;

1946

ret = seteuid(uid);

1947

if(ret == -1){

1948

perror_plus("seteuid");

1949

}

1950

goto end;

1951

}

1952

strcpy(network.ifr_name, interface);

1953

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

1954

if(ret == -1){

1955

perror_plus("ioctl SIOCGIFFLAGS");

1956

#ifdef __linux__

1957

if(restore_loglevel){

1958

ret = klogctl(7, NULL, 0);

1959

if(ret == -1){

1960

perror_plus("klogctl");

1961

}

1962

}

1963

#endif /* __linux__ */

1964

exitcode = EX_OSERR;

1965

/* Lower privileges */

1966

errno = 0;

1967

ret = seteuid(uid);

1968

if(ret == -1){

1969

perror_plus("seteuid");

1970

}

1971

goto end;

1972

}

1973

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

1974

network.ifr_flags |= IFF_UP;

1975

take_down_interface = true;

1976

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

1977

if(ret == -1){

1978

take_down_interface = false;

1979

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1980

exitcode = EX_OSERR;

1981

#ifdef __linux__

1982

if(restore_loglevel){

1983

ret = klogctl(7, NULL, 0);

1984

if(ret == -1){

1985

perror_plus("klogctl");

2720

1986

}

2721

1987

}

1988

#endif /* __linux__ */

1989

/* Lower privileges */

1990

errno = 0;

1991

ret = seteuid(uid);

1992

if(ret == -1){

1993

perror_plus("seteuid");

1994

}

1995

goto end;

1996

}

1997

}

1998

/* Sleep checking until interface is running.

1999

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

2000

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

2001

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

2002

if(ret == -1){

2003

perror_plus("ioctl SIOCGIFFLAGS");

2004

} else if(network.ifr_flags & IFF_RUNNING){

2722

2005

break;

2723

2006

}

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);

2007

struct timespec sleeptime = { .tv_nsec = 250000000 };

2008

ret = nanosleep(&sleeptime, NULL);

2009

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

2010

perror_plus("nanosleep");

2011

}

2012

}

2013

if(not take_down_interface){

2014

/* We won't need the socket anymore */

2015

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

2016

if(ret == -1){

2017

perror_plus("close");

2018

}

2019

}

2020

#ifdef __linux__

2021

if(restore_loglevel){

2022

/* Restores kernel loglevel to default */

2023

ret = klogctl(7, NULL, 0);

2024

if(ret == -1){

2025

perror_plus("klogctl");

2026

}

2027

}

2028

#endif /* __linux__ */

2029

/* Lower privileges */

2030

errno = 0;

2031

/* Lower privileges */

2032

ret = seteuid(uid);

2033

if(ret == -1){

2034

perror_plus("seteuid");

2035

}

2751

2036

}

2752

2037

2753

2038

if(quit_now){

2754

2039

goto end;

2755

2040

}

2756

2041

2757

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

2042

ret = init_gnutls_global(pubkey, seckey);

2758

2043

if(ret == -1){

2759

2044

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

2760

2045

exitcode = EX_UNAVAILABLE;

2767

2052

goto end;

2768

2053

}

2769

2054

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){

2055

if(mkdtemp(tempdir) == NULL){

2780

2056

perror_plus("mkdtemp");

2781

2057

goto end;

2782

2058

}

2059

tempdir_created = true;

2783

2060

2784

2061

if(quit_now){

2785

2062

goto end;

2786

2063

}

2787

2064

2788

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

2065

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

2789

2066

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

2790

2067

exitcode = EX_UNAVAILABLE;

2791

2068

goto end;

2801

2078

/* Connect directly, do not use Zeroconf */

2802

2079

/* (Mainly meant for debugging) */

2803

2080

char *address = strrchr(connect_to, ':');

2804

2805

2081

if(address == NULL){

2806

2082

fprintf_plus(stderr, "No colon in address\n");

2807

2083

exitcode = EX_USAGE;

2812

2088

goto end;

2813

2089

}

2814

2090

2815

in_port_t port;

2091

uint16_t port;

2816

2092

errno = 0;

2817

2093

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

2818

2094

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

2819

or tmpmax != (in_port_t)tmpmax){

2095

or tmpmax != (uint16_t)tmpmax){

2820

2096

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

2821

2097

exitcode = EX_USAGE;

2822

2098

goto end;

2823

2099

}

2824

2100

2825

2101

if(quit_now){

2826

2102

goto end;

2827

2103

}

2828

2104

2829

port = (in_port_t)tmpmax;

2105

port = (uint16_t)tmpmax;

2830

2106

*address = '\0';

2831

2107

/* Colon in address indicates IPv6 */

2832

2108

int af;

2848

2124

}

2849

2125

2850

2126

while(not quit_now){

2851

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

2852

&mc);

2127

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

2853

2128

if(quit_now or ret == 0){

2854

2129

break;

2855

2130

}

2857

2132

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

2858

2133

(int)retry_interval);

2859

2134

}

2860

sleep((unsigned int)retry_interval);

2135

sleep((int)retry_interval);

2861

2136

}

2862

2137

2863

if(not quit_now){

2138

if (not quit_now){

2864

2139

exitcode = EXIT_SUCCESS;

2865

2140

}

2866

2141

2881

2156

config.publish_domain = 0;

2882

2157

2883

2158

/* Allocate a new server */

2884

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2885

&config, NULL, NULL, &ret_errno);

2159

mc.server = avahi_server_new(avahi_simple_poll_get

2160

(mc.simple_poll), &config, NULL,

2161

NULL, &error);

2886

2162

2887

2163

/* Free the Avahi configuration data */

2888

2164

avahi_server_config_free(&config);

2891

2167

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

2892

2168

if(mc.server == NULL){

2893

2169

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

2894

avahi_strerror(ret_errno));

2170

avahi_strerror(error));

2895

2171

exitcode = EX_UNAVAILABLE;

2896

2172

goto end;

2897

2173

}

2903

2179

/* Create the Avahi service browser */

2904

2180

sb = avahi_s_service_browser_new(mc.server, if_index,

2905

2181

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2906

NULL, 0, browse_callback,

2907

(void *)&mc);

2182

NULL, 0, browse_callback, NULL);

2908

2183

if(sb == NULL){

2909

2184

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

2910

2185

avahi_strerror(avahi_server_errno(mc.server)));

2921

2196

if(debug){

2922

2197

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

2923

2198

}

2924

2925

ret = avahi_loop_with_timeout(simple_poll,

2926

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

2199

2200

ret = avahi_loop_with_timeout(mc.simple_poll,

2201

(int)(retry_interval * 1000));

2927

2202

if(debug){

2928

2203

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

2929

2204

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

2936

2211

}

2937

2212

2938

2213

/* Cleanup things */

2939

free(mc.interfaces);

2940

2941

2214

if(sb != NULL)

2942

2215

avahi_s_service_browser_free(sb);

2943

2216

2944

2217

if(mc.server != NULL)

2945

2218

avahi_server_free(mc.server);

2946

2219

2947

if(simple_poll != NULL)

2948

avahi_simple_poll_free(simple_poll);

2220

if(mc.simple_poll != NULL)

2221

avahi_simple_poll_free(mc.simple_poll);

2949

2222

2950

2223

if(gnutls_initialized){

2951

2224

gnutls_certificate_free_credentials(mc.cred);

2963

2236

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

2964

2237

while(mc.current_server != NULL){

2965

2238

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

2974

2239

free(mc.current_server);

2975

2240

mc.current_server = next;

2976

2241

}

2977

2242

}

2978

2243

2979

/* Re-raise privileges */

2244

/* Run network hooks */

2245

run_network_hooks("stop", interface, delay);

2246

2247

/* Re-raise priviliges */

2980

2248

{

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

}

2249

errno = 0;

2250

ret = seteuid(0);

2251

if(ret == -1){

2252

perror_plus("seteuid");

3008

2253

}

3009

2254

3010

ret_errno = lower_privileges_permanently();

3011

if(ret_errno != 0){

3012

errno = ret_errno;

3013

perror_plus("Failed to lower privileges permanently");

2255

/* Take down the network interface */

2256

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

2257

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

2258

if(ret == -1){

2259

perror_plus("ioctl SIOCGIFFLAGS");

2260

} else if(network.ifr_flags & IFF_UP){

2261

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

2262

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

2263

if(ret == -1){

2264

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2265

}

2266

}

2267

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

2268

if(ret == -1){

2269

perror_plus("close");

2270

}

3014

2271

}

3015

2272

}

3016

3017

free(interfaces_to_take_down);

3018

free(interfaces_hooks);

2273

/* Lower privileges permanently */

2274

errno = 0;

2275

ret = setuid(uid);

2276

if(ret == -1){

2277

perror_plus("setuid");

2278

}

3019

2279

3020

2280

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

3021

if(tempdir != NULL){

2281

if(tempdir_created){

3022

2282

struct dirent **direntries = NULL;

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

}

2283

struct dirent *direntry = NULL;

2284

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

2285

alphasort);

2286

if (numentries > 0){

2287

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

2288

direntry = direntries[i];

2289

char *fullname = NULL;

2290

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

2291

direntry->d_name);

2292

if(ret < 0){

2293

perror_plus("asprintf");

2294

continue;

2295

}

2296

ret = remove(fullname);

2297

if(ret == -1){

2298

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

2299

strerror(errno));

2300

}

2301

free(fullname);

3062

2302

}

3063

TEMP_FAILURE_RETRY(close(tempdir_fd));

2303

}

2304

2305

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

2306

free(direntries);

2307

if (numentries == -1){

2308

perror_plus("scandir");

2309

}

2310

ret = rmdir(tempdir);

2311

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

2312

perror_plus("rmdir");

3064

2313

}

3065

2314

}

3066

2315