/mandos/trunk : revision 594.1.2

9

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

10

*

11

* Everything else is

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13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#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 */

57

#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(),

93

argz_delete(), argz_append(),

94

argz_stringify(), argz_add(),

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

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

138

uid_t uid = 65534;

147

139

gid_t gid = 65534;

148

140

149

141

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

150

142

typedef struct server{

151

143

const char *ip;

152

in_port_t port;

144

uint16_t port;

153

145

AvahiIfIndex if_index;

154

146

int af;

155

147

struct timespec last_seen;

159

151

160

152

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

161

153

typedef struct {

154

AvahiSimplePoll *simple_poll;

162

155

AvahiServer *server;

163

156

gnutls_certificate_credentials_t cred;

164

157

unsigned int dh_bits;

166

159

const char *priority;

167

160

gpgme_ctx_t ctx;

168

161

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

171

162

} mandos_context;

172

163

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

164

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

165

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

166

.dh_bits = 1024, .priority = "SECURE256"

167

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

168

.current_server = NULL };

175

169

176

170

sig_atomic_t quit_now = 0;

177

171

int signal_received = 0;

185

179

perror(print_text);

186

180

}

187

181

188

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

182

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

189

183

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

190

184

va_list ap;

191

185

va_start (ap, format);

192

186

193

187

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

194

188

program_invocation_short_name));

195

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

189

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

196

190

}

197

191

198

192

/*

200

194

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

201

195

* "buffer_length" is how much is already used.

202

196

*/

203

__attribute__((nonnull, warn_unused_result))

204

197

size_t incbuffer(char **buffer, size_t buffer_length,

205

198

size_t buffer_capacity){

206

199

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;

200

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

201

if(buffer == NULL){

213

202

return 0;

214

203

}

215

*buffer = new_buf;

216

204

buffer_capacity += BUFFER_SIZE;

217

205

}

218

206

return buffer_capacity;

219

207

}

220

208

221

209

/* 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){

210

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

211

int af){

225

212

int ret;

226

213

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

227

214

if(new_server == NULL){

234

221

.af = af };

235

222

if(new_server->ip == NULL){

236

223

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

224

return false;

253

225

}

254

226

/* Special case of first server */

255

if(*current_server == NULL){

227

if (mc.current_server == NULL){

256

228

new_server->next = new_server;

257

229

new_server->prev = new_server;

258

*current_server = new_server;

230

mc.current_server = new_server;

231

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

259

232

} else {

260

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

261

new_server->next = *current_server;

262

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

233

new_server->next = mc.current_server;

234

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

263

235

new_server->prev->next = new_server;

264

(*current_server)->prev = new_server;

236

mc.current_server->prev = new_server;

237

}

238

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

239

if(ret == -1){

240

perror_plus("clock_gettime");

241

return false;

265

242

}

266

243

return true;

267

244

}

269

246

/*

270

247

* Initialize GPGME.

271

248

*/

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){

249

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

250

const char *tempdir){

277

251

gpgme_error_t rc;

278

252

gpgme_engine_info_t engine_info;

279

253

254

280

255

/*

281

256

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

282

257

*/

283

bool import_key(const char * const filename){

258

bool import_key(const char *filename){

284

259

int ret;

285

260

int fd;

286

261

gpgme_data_t pgp_data;

298

273

return false;

299

274

}

300

275

301

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

276

rc = gpgme_op_import(mc.ctx, pgp_data);

302

277

if(rc != GPG_ERR_NO_ERROR){

303

278

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

304

279

gpgme_strsource(rc), gpgme_strerror(rc));

348

323

}

349

324

350

325

/* Create new GPGME "context" */

351

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

326

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

352

327

if(rc != GPG_ERR_NO_ERROR){

353

328

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

354

329

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

367

342

* Decrypt OpenPGP data.

368

343

* Returns -1 on error

369

344

*/

370

__attribute__((nonnull, warn_unused_result))

371

345

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

346

size_t crypto_size,

373

char **plaintext,

374

mandos_context *mc){

347

char **plaintext){

375

348

gpgme_data_t dh_crypto, dh_plain;

376

349

gpgme_error_t rc;

377

350

ssize_t ret;

403

376

404

377

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

405

378

data buffer */

406

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

379

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

407

380

if(rc != GPG_ERR_NO_ERROR){

408

381

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

409

382

gpgme_strsource(rc), gpgme_strerror(rc));

410

383

plaintext_length = -1;

411

384

if(debug){

412

385

gpgme_decrypt_result_t result;

413

result = gpgme_op_decrypt_result(mc->ctx);

386

result = gpgme_op_decrypt_result(mc.ctx);

414

387

if(result == NULL){

415

388

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

416

389

} else {

493

466

return plaintext_length;

494

467

}

495

468

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);

469

static const char * safer_gnutls_strerror(int value){

470

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

471

-Wunreachable-code */

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

507

475

}

508

476

509

477

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

478

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

512

479

const char* string){

513

480

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

514

481

}

515

482

516

__attribute__((nonnull, warn_unused_result))

517

483

static int init_gnutls_global(const char *pubkeyfilename,

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

mandos_context *mc){

484

const char *seckeyfilename){

521

485

int ret;

522

unsigned int uret;

523

486

524

487

if(debug){

525

488

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

541

504

}

542

505

543

506

/* OpenPGP credentials */

544

ret = gnutls_certificate_allocate_credentials(&mc->cred);

507

ret = gnutls_certificate_allocate_credentials(&mc.cred);

545

508

if(ret != GNUTLS_E_SUCCESS){

546

509

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

547

510

safer_gnutls_strerror(ret));

557

520

}

558

521

559

522

ret = gnutls_certificate_set_openpgp_key_file

560

(mc->cred, pubkeyfilename, seckeyfilename,

523

(mc.cred, pubkeyfilename, seckeyfilename,

561

524

GNUTLS_OPENPGP_FMT_BASE64);

562

525

if(ret != GNUTLS_E_SUCCESS){

563

526

fprintf_plus(stderr,

569

532

}

570

533

571

534

/* GnuTLS server initialization */

572

ret = gnutls_dh_params_init(&mc->dh_params);

535

ret = gnutls_dh_params_init(&mc.dh_params);

573

536

if(ret != GNUTLS_E_SUCCESS){

574

537

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

575

538

" initialization: %s\n",

576

539

safer_gnutls_strerror(ret));

577

540

goto globalfail;

578

541

}

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);

542

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

543

if(ret != GNUTLS_E_SUCCESS){

544

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

545

safer_gnutls_strerror(ret));

546

goto globalfail;

547

}

548

549

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

752

550

753

551

return 0;

754

552

755

553

globalfail:

756

554

757

gnutls_certificate_free_credentials(mc->cred);

555

gnutls_certificate_free_credentials(mc.cred);

758

556

gnutls_global_deinit();

759

gnutls_dh_params_deinit(mc->dh_params);

557

gnutls_dh_params_deinit(mc.dh_params);

760

558

return -1;

761

559

}

762

560

763

__attribute__((nonnull, warn_unused_result))

764

static int init_gnutls_session(gnutls_session_t *session,

765

mandos_context *mc){

561

static int init_gnutls_session(gnutls_session_t *session){

766

562

int ret;

767

563

/* GnuTLS session creation */

768

564

do {

780

576

{

781

577

const char *err;

782

578

do {

783

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

579

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

784

580

if(quit_now){

785

581

gnutls_deinit(*session);

786

582

return -1;

797

593

798

594

do {

799

595

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

800

mc->cred);

596

mc.cred);

801

597

if(quit_now){

802

598

gnutls_deinit(*session);

803

599

return -1;

813

609

/* ignore client certificate if any. */

814

610

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

611

612

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

613

816

614

return 0;

817

615

}

818

616

820

618

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

821

619

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

822

620

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

621

/* 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,

622

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

1043

623

AvahiIfIndex if_index,

1044

int af, mandos_context *mc){

624

int af){

1045

625

int ret, tcp_sd = -1;

1046

626

ssize_t sret;

1047

struct sockaddr_storage to;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

1048

631

char *buffer = NULL;

1049

632

char *decrypted_buffer = NULL;

1050

633

size_t buffer_length = 0;

1053

636

int retval = -1;

1054

637

gnutls_session_t session;

1055

638

int pf; /* Protocol family */

1056

bool route_added = false;

1057

639

1058

640

errno = 0;

1059

641

1075

657

return -1;

1076

658

}

1077

659

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);

660

ret = init_gnutls_session(&session);

1111

661

if(ret != 0){

1112

662

return -1;

1113

663

}

1114

664

1115

665

if(debug){

1116

666

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

1117

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

667

PRIu16 "\n", ip, port);

1118

668

}

1119

669

1120

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

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

671

if(tcp_sd < 0){

1122

672

int e = errno;

1123

673

perror_plus("socket");

1132

682

1133

683

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

1134

684

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);

685

to.in6.sin6_family = (sa_family_t)af;

686

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

1137

687

} 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);

688

to.in.sin_family = (sa_family_t)af;

689

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

1140

690

}

1141

691

if(ret < 0 ){

1142

692

int e = errno;

1151

701

goto mandos_end;

1152

702

}

1153

703

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)){

704

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

705

-Wconversion and

706

-Wunreachable-code */

707

708

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

709

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

710

-Wunreachable-code*/

1157

711

if(if_index == AVAHI_IF_UNSPEC){

1158

712

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

1159

713

" incomplete without a network interface\n");

1161

715

goto mandos_end;

1162

716

}

1163

717

/* Set the network interface number as scope */

1164

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

718

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

719

}

1166

720

} else {

1167

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

721

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

722

-Wconversion and

723

-Wunreachable-code */

1168

724

}

1169

725

1170

726

if(quit_now){

1178

734

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

1179

735

perror_plus("if_indextoname");

1180

736

} else {

1181

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

1182

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

737

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

738

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

1183

739

}

1184

740

} else {

1185

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

1186

ip, (uintmax_t)port);

741

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

742

ip, port);

1187

743

}

1188

744

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1189

745

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;

746

const char *pcret;

747

if(af == AF_INET6){

748

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

749

sizeof(addrstr));

750

} else {

751

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

752

sizeof(addrstr));

753

}

754

if(pcret == NULL){

755

perror_plus("inet_ntop");

756

} else {

757

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

758

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

759

}

760

}

761

}

762

763

if(quit_now){

764

errno = EINTR;

765

goto mandos_end;

766

}

767

768

if(af == AF_INET6){

769

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

770

} else {

771

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

772

}

773

if(ret < 0){

774

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

775

int e = errno;

776

perror_plus("connect");

777

errno = e;

778

}

779

goto mandos_end;

780

}

781

782

if(quit_now){

783

errno = EINTR;

784

goto mandos_end;

1270

785

}

1271

786

1272

787

const char *out = mandos_protocol_version;

1423

938

if(buffer_length > 0){

1424

939

ssize_t decrypted_buffer_size;

1425

940

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1426

&decrypted_buffer, mc);

941

&decrypted_buffer);

1427

942

if(decrypted_buffer_size >= 0){

1428

943

1429

944

written = 0;

1455

970

1456

971

mandos_end:

1457

972

{

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

973

int e = errno;

1465

974

free(decrypted_buffer);

1466

975

free(buffer);

1483

992

return retval;

1484

993

}

1485

994

1486

__attribute__((nonnull))

1487

995

static void resolve_callback(AvahiSServiceResolver *r,

1488

996

AvahiIfIndex interface,

1489

997

AvahiProtocol proto,

1497

1005

AVAHI_GCC_UNUSED AvahiStringList *txt,

1498

1006

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1499

1007

flags,

1500

void *mc){

1501

if(r == NULL){

1502

return;

1503

}

1008

AVAHI_GCC_UNUSED void* userdata){

1009

assert(r);

1504

1010

1505

1011

/* Called whenever a service has been resolved successfully or

1506

1012

timed out */

1507

1013

1508

1014

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1510

1015

return;

1511

1016

}

1512

1017

1516

1021

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

1517

1022

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

1518

1023

domain,

1519

avahi_strerror(avahi_server_errno

1520

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

1024

avahi_strerror(avahi_server_errno(mc.server)));

1521

1025

break;

1522

1026

1523

1027

case AVAHI_RESOLVER_FOUND:

1529

1033

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

1530

1034

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

1531

1035

}

1532

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

1533

interface,

1534

avahi_proto_to_af(proto),

1535

mc);

1036

int ret = start_mandos_communication(ip, port, interface,

1037

avahi_proto_to_af(proto));

1536

1038

if(ret == 0){

1537

avahi_simple_poll_quit(simple_poll);

1039

avahi_simple_poll_quit(mc.simple_poll);

1538

1040

} else {

1539

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

1540

avahi_proto_to_af(proto),

1541

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

1041

if(not add_server(ip, port, interface,

1042

avahi_proto_to_af(proto))){

1542

1043

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

1543

1044

" list\n", name);

1544

1045

}

1557

1058

const char *domain,

1558

1059

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1559

1060

flags,

1560

void *mc){

1561

if(b == NULL){

1562

return;

1563

}

1061

AVAHI_GCC_UNUSED void* userdata){

1062

assert(b);

1564

1063

1565

1064

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

1566

1065

is removed from the LAN */

1574

1073

case AVAHI_BROWSER_FAILURE:

1575

1074

1576

1075

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);

1076

avahi_strerror(avahi_server_errno(mc.server)));

1077

avahi_simple_poll_quit(mc.simple_poll);

1580

1078

return;

1581

1079

1582

1080

case AVAHI_BROWSER_NEW:

1585

1083

the callback function is called the Avahi server will free the

1586

1084

resolver for us. */

1587

1085

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)

1086

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

1087

name, type, domain, protocol, 0,

1088

resolve_callback, NULL) == NULL)

1592

1089

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

1593

1090

" %s\n", name,

1594

avahi_strerror(avahi_server_errno

1595

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

1091

avahi_strerror(avahi_server_errno(mc.server)));

1596

1092

break;

1597

1093

1598

1094

case AVAHI_BROWSER_REMOVE:

1617

1113

signal_received = sig;

1618

1114

int old_errno = errno;

1619

1115

/* set main loop to exit */

1620

if(simple_poll != NULL){

1621

avahi_simple_poll_quit(simple_poll);

1116

if(mc.simple_poll != NULL){

1117

avahi_simple_poll_quit(mc.simple_poll);

1622

1118

}

1623

1119

errno = old_errno;

1624

1120

}

1625

1121

1626

__attribute__((nonnull, warn_unused_result))

1627

1122

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

1628

1123

int ret;

1629

error_t ret_errno;

1630

1124

1631

1125

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

1632

1126

if(s < 0){

1633

ret_errno = errno;

1634

1127

perror_plus("socket");

1635

errno = ret_errno;

1636

1128

return false;

1637

1129

}

1638

1130

strcpy(ifr->ifr_name, ifname);

1639

1131

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1640

1132

if(ret == -1){

1641

1133

if(debug){

1642

ret_errno = errno;

1643

1134

perror_plus("ioctl SIOCGIFFLAGS");

1644

errno = ret_errno;

1645

1135

}

1646

1136

return false;

1647

1137

}

1648

1138

return true;

1649

1139

}

1650

1140

1651

__attribute__((nonnull, warn_unused_result))

1652

1141

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

1653

1142

1654

1143

/* Reject the loopback device */

1696

1185

* corresponds to an acceptable network device.

1697

1186

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

1698

1187

*/

1699

__attribute__((nonnull, warn_unused_result))

1700

1188

int good_interface(const struct dirent *if_entry){

1701

1189

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

1702

1190

return 0;

1718

1206

}

1719

1207

1720

1208

/*

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))

1209

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

1210

* corresponds to an acceptable network device which is up.

1211

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

1212

*/

1213

int up_interface(const struct dirent *if_entry){

1214

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

1215

return 0;

1216

}

1217

1218

struct ifreq ifr;

1219

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

1220

if(debug){

1221

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

1222

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

1223

}

1224

return 0;

1225

}

1226

1227

/* Reject down interfaces */

1228

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

1229

if(debug){

1230

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

1231

if_entry->d_name);

1232

}

1233

return 0;

1234

}

1235

1236

/* Reject non-running interfaces */

1237

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

1238

if(debug){

1239

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

1240

if_entry->d_name);

1241

}

1242

return 0;

1243

}

1244

1245

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

1246

return 0;

1247

}

1248

return 1;

1249

}

1250

1755

1251

int notdotentries(const struct dirent *direntry){

1756

1252

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

1757

1253

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

1764

1260

}

1765

1261

1766

1262

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

1767

__attribute__((nonnull, warn_unused_result))

1768

1263

int runnable_hook(const struct dirent *direntry){

1769

1264

int ret;

1770

1265

size_t sret;

1778

1273

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

1779

1274

"abcdefghijklmnopqrstuvwxyz"

1780

1275

"0123456789"

1781

"_.-");

1276

"_-");

1782

1277

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

1783

1278

/* Contains non-allowed characters */

1784

1279

if(debug){

1788

1283

return 0;

1789

1284

}

1790

1285

1791

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

1286

char *fullname = NULL;

1287

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

1288

if(ret < 0){

1289

perror_plus("asprintf");

1290

return 0;

1291

}

1292

1293

ret = stat(fullname, &st);

1792

1294

if(ret == -1){

1793

1295

if(debug){

1794

1296

perror_plus("Could not stat hook");

1818

1320

return 1;

1819

1321

}

1820

1322

1821

__attribute__((nonnull, warn_unused_result))

1822

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1823

mandos_context *mc){

1323

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1824

1324

int ret;

1825

1325

struct timespec now;

1826

1326

struct timespec waited_time;

1827

1327

intmax_t block_time;

1828

1328

1829

1329

while(true){

1830

if(mc->current_server == NULL){

1831

if(debug){

1330

if(mc.current_server == NULL){

1331

if (debug){

1832

1332

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

1833

1333

" No timeout!\n");

1834

1334

}

1835

1335

ret = avahi_simple_poll_iterate(s, -1);

1836

1336

} else {

1837

if(debug){

1337

if (debug){

1838

1338

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

1839

1339

" it, or wait\n");

1840

1340

}

1847

1347

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

1848

1348

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

1849

1349

waited_time.tv_sec = (now.tv_sec

1850

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

1350

- mc.current_server->last_seen.tv_sec);

1851

1351

waited_time.tv_nsec = (now.tv_nsec

1852

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

1352

- mc.current_server->last_seen.tv_nsec);

1853

1353

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

1854

1354

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

1855

1355

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

1857

1357

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

1858

1358

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

1859

1359

1860

if(debug){

1360

if (debug){

1861

1361

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

1862

1362

block_time);

1863

1363

}

1864

1364

1865

1365

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);

1366

ret = start_mandos_communication(mc.current_server->ip,

1367

mc.current_server->port,

1368

mc.current_server->if_index,

1369

mc.current_server->af);

1870

1370

if(ret == 0){

1871

avahi_simple_poll_quit(s);

1371

avahi_simple_poll_quit(mc.simple_poll);

1872

1372

return 0;

1873

1373

}

1874

1374

ret = clock_gettime(CLOCK_MONOTONIC,

1875

&mc->current_server->last_seen);

1375

&mc.current_server->last_seen);

1876

1376

if(ret == -1){

1877

1377

perror_plus("clock_gettime");

1878

1378

return -1;

1879

1379

}

1880

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

1380

mc.current_server = mc.current_server->next;

1881

1381

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

1882

1382

servers, but don't block */

1883

1383

}

1885

1385

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

1886

1386

}

1887

1387

if(ret != 0){

1888

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

1388

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

1889

1389

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

1890

1390

}

1891

1391

}

1892

1392

}

1893

1393

}

1894

1394

1895

__attribute__((nonnull))

1896

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

1395

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

1396

int raise_privileges(void){

1397

int old_errno = errno;

1398

int ret_errno = 0;

1399

errno = 0;

1400

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

1401

perror_plus("seteuid");

1402

}

1403

ret_errno = errno;

1404

errno = old_errno;

1405

return ret_errno;

1406

}

1407

1408

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

1409

int raise_privileges_permanently(void){

1410

int old_errno = errno;

1411

int ret_errno = raise_privileges();

1412

if(ret_errno != 0){

1413

errno = old_errno;

1414

return ret_errno;

1415

}

1416

errno = 0;

1417

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

1418

perror_plus("seteuid");

1419

}

1420

ret_errno = errno;

1421

errno = old_errno;

1422

return ret_errno;

1423

}

1424

1425

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

1426

int lower_privileges(void){

1427

int old_errno = errno;

1428

int ret_errno = 0;

1429

errno = 0;

1430

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

1431

perror_plus("seteuid");

1432

}

1433

ret_errno = errno;

1434

errno = old_errno;

1435

return ret_errno;

1436

}

1437

1438

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

1897

1439

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__ */

1440

struct dirent **direntries;

1441

struct dirent *direntry;

1442

int ret;

1443

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

1444

alphasort);

1926

1445

if(numhooks == -1){

1927

1446

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){

1447

} else {

1448

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

1449

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

1450

direntry = direntries[i];

1451

char *fullname = NULL;

1452

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

1453

if(ret < 0){

1989

1454

perror_plus("asprintf");

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1455

continue;

1456

}

1457

if(debug){

1458

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

1459

direntry->d_name);

1460

}

1461

pid_t hook_pid = fork();

1462

if(hook_pid == 0){

1463

/* Child */

1464

/* Raise privileges */

1465

raise_privileges_permanently();

1466

/* Set group */

1467

errno = 0;

1468

ret = setgid(0);

1469

if(ret == -1){

1470

perror_plus("setgid");

1471

}

1472

/* Reset supplementary groups */

1473

errno = 0;

1474

ret = setgroups(0, NULL);

1475

if(ret == -1){

1476

perror_plus("setgroups");

1477

}

1478

dup2(devnull, STDIN_FILENO);

1479

close(devnull);

1480

dup2(STDERR_FILENO, STDOUT_FILENO);

1481

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

1482

if(ret == -1){

1483

perror_plus("setenv");

1484

_exit(EX_OSERR);

1485

}

1486

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

1487

if(ret == -1){

1488

perror_plus("setenv");

1489

_exit(EX_OSERR);

1490

}

1491

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

1492

if(ret == -1){

1493

perror_plus("setenv");

1494

_exit(EX_OSERR);

1495

}

1496

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

1497

if(ret == -1){

1498

perror_plus("setenv");

1499

_exit(EX_OSERR);

1500

}

1501

char *delaystring;

1502

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

1503

if(ret == -1){

1504

perror_plus("asprintf");

1505

_exit(EX_OSERR);

1506

}

1507

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

1508

if(ret == -1){

1509

free(delaystring);

1510

perror_plus("setenv");

1511

_exit(EX_OSERR);

1512

}

1994

1513

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;

1514

if(connect_to != NULL){

1515

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

1516

if(ret == -1){

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1520

}

1521

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

1522

perror_plus("execl");

1523

_exit(EXIT_FAILURE);

1524

}

2063

1525

} 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);

1526

int status;

1527

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

1528

perror_plus("waitpid");

1529

free(fullname);

1530

continue;

1531

}

1532

if(WIFEXITED(status)){

1533

if(WEXITSTATUS(status) != 0){

1534

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

1535

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

1536

WEXITSTATUS(status));

1537

free(fullname);

1538

continue;

1539

}

1540

} else if(WIFSIGNALED(status)){

1541

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

1542

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

1543

WTERMSIG(status));

1544

free(fullname);

1545

continue;

1546

} else {

1547

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

1548

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

1549

free(fullname);

1550

continue;

1551

}

1552

}

1553

free(fullname);

1554

if(debug){

1555

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

1556

direntry->d_name);

1557

}

1558

}

1559

close(devnull);

1560

}

1561

return true;

2083

1562

}

2084

1563

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;

1564

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

1565

int sd = -1;

1566

int old_errno = errno;

1567

int ret_errno = 0;

2089

1568

int ret;

2090

1569

struct ifreq network;

2091

unsigned int if_index = if_nametoindex(interface);

1570

AvahiIfIndex if_index = (AvahiIfIndex)if_nametoindex(interface);

2092

1571

if(if_index == 0){

2093

1572

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

2094

1573

errno = old_errno;

2100

1579

return EINTR;

2101

1580

}

2102

1581

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));

1582

/* Re-raise priviliges */

1583

raise_privileges();

1584

1585

#ifdef __linux__

1586

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1587

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

1588

ret = klogctl(8, NULL, 5);

1589

bool restore_loglevel = true;

1590

if(ret == -1){

1591

restore_loglevel = false;

1592

perror_plus("klogctl");

1593

}

1594

#endif /* __linux__ */

1595

1596

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1597

if(sd < 0){

1598

ret_errno = errno;

1599

perror_plus("socket");

1600

#ifdef __linux__

1601

if(restore_loglevel){

1602

ret = klogctl(7, NULL, 0);

1603

if(ret == -1){

1604

perror_plus("klogctl");

1605

}

1606

}

1607

#endif /* __linux__ */

1608

/* Lower privileges */

1609

lower_privileges();

1610

errno = old_errno;

1611

return ret_errno;

1612

}

1613

strcpy(network.ifr_name, interface);

1614

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

1615

if(ret == -1){

1616

ret_errno = errno;

1617

perror_plus("ioctl SIOCGIFFLAGS");

1618

#ifdef __linux__

1619

if(restore_loglevel){

1620

ret = klogctl(7, NULL, 0);

1621

if(ret == -1){

1622

perror_plus("klogctl");

1623

}

1624

}

1625

#endif /* __linux__ */

1626

/* Lower privileges */

1627

lower_privileges();

1628

errno = old_errno;

1629

return ret_errno;

1630

}

1631

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

1632

network.ifr_flags |= IFF_UP;

1633

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

2180

1634

if(ret == -1){

2181

perror_plus("close");

2182

}

2183

2184

if(ret_setflags == -1){

2185

errno = ioctl_errno;

1635

ret_errno = errno;

2186

1636

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1637

#ifdef __linux__

1638

if(restore_loglevel){

1639

ret = klogctl(7, NULL, 0);

1640

if(ret == -1){

1641

perror_plus("klogctl");

1642

}

1643

}

1644

#endif /* __linux__ */

1645

/* Lower privileges */

1646

lower_privileges();

2187

1647

errno = old_errno;

2188

return ioctl_errno;

1648

return ret_errno;

2189

1649

}

2190

} else if(debug){

2191

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

2192

interface);

2193

1650

}

2194

2195

1651

/* Sleep checking until interface is running.

2196

1652

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

2197

1653

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

2198

if(interface_is_running(interface)){

1654

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

1655

if(ret == -1){

1656

perror_plus("ioctl SIOCGIFFLAGS");

1657

} else if(network.ifr_flags & IFF_RUNNING){

2199

1658

break;

2200

1659

}

2201

1660

struct timespec sleeptime = { .tv_nsec = 250000000 };

2204

1663

perror_plus("nanosleep");

2205

1664

}

2206

1665

}

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;

1666

/* Close the socket */

1667

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

1668

if(ret == -1){

1669

perror_plus("close");

2221

1670

}

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));

1671

#ifdef __linux__

1672

if(restore_loglevel){

1673

/* Restores kernel loglevel to default */

1674

ret = klogctl(7, NULL, 0);

2268

1675

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);

1676

perror_plus("klogctl");

1677

}

2281

1678

}

2282

1679

#endif /* __linux__ */

1680

/* Lower privileges */

1681

lower_privileges();

2283

1682

errno = old_errno;

2284

1683

return 0;

2285

1684

}

2286

1685

2287

1686

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

1687

AvahiSServiceBrowser *sb = NULL;

2293

error_t ret_errno;

1688

int error;

2294

1689

int ret;

2295

1690

intmax_t tmpmax;

2296

1691

char *tmp;

2297

1692

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;

1693

const char *interface = "";

1694

struct ifreq network;

1695

int sd = -1;

1696

bool take_down_interface = false;

1697

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

1698

bool tempdir_created = false;

2303

1699

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2304

1700

const char *seckey = PATHDIR "/" SECKEY;

2305

1701

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

char *interfaces_hooks = NULL;

2308

1702

2309

1703

bool gnutls_initialized = false;

2310

1704

bool gpgme_initialized = false;

2362

1756

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

2363

1757

" Diffie-Hellman key exchange",

2364

1758

.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

1759

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

2371

1760

.arg = "STRING",

2372

1761

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

2406

1795

connect_to = arg;

2407

1796

break;

2408

1797

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

}

1798

interface = arg;

2414

1799

break;

2415

1800

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

2416

1801

seckey = arg;

2427

1812

}

2428

1813

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

2429

1814

break;

2430

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

2431

dh_params_file = arg;

2432

break;

2433

1815

case 130: /* --priority */

2434

1816

mc.priority = arg;

2435

1817

break;

2491

1873

goto end;

2492

1874

}

2493

1875

}

2494

1876

2495

1877

{

2496

1878

/* Work around Debian bug #633582:

2497

1879

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

2498

1880

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 {

1881

/* Re-raise priviliges */

1882

if(raise_privileges() == 0){

2505

1883

struct stat st;

2506

1884

2507

1885

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

2524

1902

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

1903

}

2526

1904

}

2527

1905

2528

1906

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

2529

1907

int pubkey_fd = open(pubkey, O_RDONLY);

2530

1908

if(pubkey_fd == -1){

2545

1923

TEMP_FAILURE_RETRY(close(pubkey_fd));

2546

1924

}

2547

1925

}

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

1926

2570

1927

/* Lower privileges */

2571

ret_errno = lower_privileges();

2572

if(ret_errno != 0){

2573

errno = ret_errno;

2574

perror_plus("Failed to lower privileges");

2575

}

2576

}

2577

}

2578

2579

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

2580

{

2581

char *interface = NULL;

2582

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

2583

interface))){

2584

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

2585

and if_nametoindex(interface) == 0){

2586

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

2587

fprintf_plus(stderr, "Not using nonexisting interface"

2588

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

2589

}

2590

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

2591

interface = NULL;

1928

errno = 0;

1929

ret = seteuid(uid);

1930

if(ret == -1){

1931

perror_plus("seteuid");

2592

1932

}

2593

1933

}

2594

1934

}

2595

1935

2596

1936

/* Run network hooks */

2597

{

2598

if(mc.interfaces != NULL){

2599

interfaces_hooks = malloc(mc.interfaces_size);

2600

if(interfaces_hooks == NULL){

1937

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

1938

goto end;

1939

}

1940

1941

if(not debug){

1942

avahi_set_log_function(empty_log);

1943

}

1944

1945

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

1946

struct dirent **direntries;

1947

/* First look for interfaces that are up */

1948

ret = scandir(sys_class_net, &direntries, up_interface,

1949

alphasort);

1950

if(ret == 0){

1951

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

1952

free(direntries);

1953

ret = scandir(sys_class_net, &direntries, good_interface,

1954

alphasort);

1955

}

1956

if(ret >= 1){

1957

/* Pick the first interface returned */

1958

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

1959

if(debug){

1960

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

1961

}

1962

if(interface == NULL){

2601

1963

perror_plus("malloc");

1964

free(direntries);

1965

exitcode = EXIT_FAILURE;

2602

1966

goto end;

2603

1967

}

2604

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

2605

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

1968

free(direntries);

1969

} else {

1970

free(direntries);

1971

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

1972

exitcode = EXIT_FAILURE;

1973

goto end;

2606

1974

}

2607

run_network_hooks("start", interfaces_hooks != NULL ?

2608

interfaces_hooks : "", delay);

2609

}

2610

2611

if(not debug){

2612

avahi_set_log_function(empty_log);

2613

1975

}

2614

1976

2615

1977

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

2616

1978

from the signal handler */

2617

1979

/* Initialize the pseudo-RNG for Avahi */

2618

1980

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

2619

simple_poll = avahi_simple_poll_new();

2620

if(simple_poll == NULL){

1981

mc.simple_poll = avahi_simple_poll_new();

1982

if(mc.simple_poll == NULL){

2621

1983

fprintf_plus(stderr,

2622

1984

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

2623

1985

exitcode = EX_UNAVAILABLE;

2687

2049

}

2688

2050

}

2689

2051

2690

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

2691

if(mc.interfaces == NULL){

2692

struct dirent **direntries = NULL;

2693

/* Look for any good interfaces */

2694

ret = scandir(sys_class_net, &direntries, good_interface,

2695

alphasort);

2696

if(ret >= 1){

2697

/* Add all found interfaces to interfaces list */

2698

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

2699

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

2700

direntries[i]->d_name);

2701

if(ret_errno != 0){

2702

errno = ret_errno;

2703

perror_plus("argz_add");

2704

free(direntries[i]);

2705

continue;

2706

}

2707

if(debug){

2708

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

2709

direntries[i]->d_name);

2710

}

2711

free(direntries[i]);

2712

}

2713

free(direntries);

2714

} else {

2715

if(ret == 0){

2716

free(direntries);

2717

}

2718

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

2719

exitcode = EXIT_FAILURE;

2720

goto end;

2721

}

2722

}

2723

2724

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

2725

{

2726

char *interface = NULL;

2727

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

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

}

2745

bool interface_was_up = interface_is_up(interface);

2746

errno = bring_up_interface(interface, delay);

2747

if(not interface_was_up){

2748

if(errno != 0){

2749

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

2750

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

2751

} else {

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

}

2758

}

2759

}

2760

}

2761

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

2762

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

2763

}

2764

}

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);

2052

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

2053

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

2054

ret = bring_up_interface(interface, delay);

2055

if(ret != 0){

2056

errno = ret;

2057

perror_plus("Failed to bring up interface");

2058

}

2773

2059

}

2774

2060

2775

2061

if(quit_now){

2776

2062

goto end;

2777

2063

}

2778

2064

2779

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

2065

ret = init_gnutls_global(pubkey, seckey);

2780

2066

if(ret == -1){

2781

2067

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

2782

2068

exitcode = EX_UNAVAILABLE;

2789

2075

goto end;

2790

2076

}

2791

2077

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){

2078

if(mkdtemp(tempdir) == NULL){

2802

2079

perror_plus("mkdtemp");

2803

2080

goto end;

2804

2081

}

2082

tempdir_created = true;

2805

2083

2806

2084

if(quit_now){

2807

2085

goto end;

2808

2086

}

2809

2087

2810

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

2088

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

2811

2089

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

2812

2090

exitcode = EX_UNAVAILABLE;

2813

2091

goto end;

2834

2112

goto end;

2835

2113

}

2836

2114

2837

in_port_t port;

2115

uint16_t port;

2838

2116

errno = 0;

2839

2117

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

2840

2118

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

2841

or tmpmax != (in_port_t)tmpmax){

2119

or tmpmax != (uint16_t)tmpmax){

2842

2120

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

2843

2121

exitcode = EX_USAGE;

2844

2122

goto end;

2845

2123

}

2846

2124

2847

2125

if(quit_now){

2848

2126

goto end;

2849

2127

}

2850

2128

2851

port = (in_port_t)tmpmax;

2129

port = (uint16_t)tmpmax;

2852

2130

*address = '\0';

2853

2131

/* Colon in address indicates IPv6 */

2854

2132

int af;

2870

2148

}

2871

2149

2872

2150

while(not quit_now){

2873

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

2874

&mc);

2151

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

2875

2152

if(quit_now or ret == 0){

2876

2153

break;

2877

2154

}

2879

2156

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

2880

2157

(int)retry_interval);

2881

2158

}

2882

sleep((unsigned int)retry_interval);

2159

sleep((int)retry_interval);

2883

2160

}

2884

2161

2885

if(not quit_now){

2162

if (not quit_now){

2886

2163

exitcode = EXIT_SUCCESS;

2887

2164

}

2888

2165

2903

2180

config.publish_domain = 0;

2904

2181

2905

2182

/* Allocate a new server */

2906

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2907

&config, NULL, NULL, &ret_errno);

2183

mc.server = avahi_server_new(avahi_simple_poll_get

2184

(mc.simple_poll), &config, NULL,

2185

NULL, &error);

2908

2186

2909

2187

/* Free the Avahi configuration data */

2910

2188

avahi_server_config_free(&config);

2913

2191

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

2914

2192

if(mc.server == NULL){

2915

2193

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

2916

avahi_strerror(ret_errno));

2194

avahi_strerror(error));

2917

2195

exitcode = EX_UNAVAILABLE;

2918

2196

goto end;

2919

2197

}

2925

2203

/* Create the Avahi service browser */

2926

2204

sb = avahi_s_service_browser_new(mc.server, if_index,

2927

2205

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2928

NULL, 0, browse_callback,

2929

(void *)&mc);

2206

NULL, 0, browse_callback, NULL);

2930

2207

if(sb == NULL){

2931

2208

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

2932

2209

avahi_strerror(avahi_server_errno(mc.server)));

2943

2220

if(debug){

2944

2221

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

2945

2222

}

2946

2947

ret = avahi_loop_with_timeout(simple_poll,

2948

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

2223

2224

ret = avahi_loop_with_timeout(mc.simple_poll,

2225

(int)(retry_interval * 1000));

2949

2226

if(debug){

2950

2227

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

2951

2228

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

2958

2235

}

2959

2236

2960

2237

/* Cleanup things */

2961

free(mc.interfaces);

2962

2963

2238

if(sb != NULL)

2964

2239

avahi_s_service_browser_free(sb);

2965

2240

2966

2241

if(mc.server != NULL)

2967

2242

avahi_server_free(mc.server);

2968

2243

2969

if(simple_poll != NULL)

2970

avahi_simple_poll_free(simple_poll);

2244

if(mc.simple_poll != NULL)

2245

avahi_simple_poll_free(mc.simple_poll);

2971

2246

2972

2247

if(gnutls_initialized){

2973

2248

gnutls_certificate_free_credentials(mc.cred);

2985

2260

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

2986

2261

while(mc.current_server != NULL){

2987

2262

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

2996

2263

free(mc.current_server);

2997

2264

mc.current_server = next;

2998

2265

}

2999

2266

}

3000

2267

3001

/* Re-raise privileges */

2268

/* Run network hooks */

2269

run_network_hooks("stop", interface, delay);

2270

2271

/* Re-raise priviliges */

3002

2272

{

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

}

2273

raise_privileges();

3031

2274

3032

ret_errno = lower_privileges_permanently();

3033

if(ret_errno != 0){

3034

errno = ret_errno;

3035

perror_plus("Failed to lower privileges permanently");

2275

/* Take down the network interface */

2276

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

2277

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

2278

if(ret == -1){

2279

perror_plus("ioctl SIOCGIFFLAGS");

2280

} else if(network.ifr_flags & IFF_UP){

2281

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

2282

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

2283

if(ret == -1){

2284

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2285

}

2286

}

2287

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

2288

if(ret == -1){

2289

perror_plus("close");

2290

}

3036

2291

}

3037

2292

}

3038

3039

free(interfaces_to_take_down);

3040

free(interfaces_hooks);

2293

/* Lower privileges permanently */

2294

errno = 0;

2295

ret = setuid(uid);

2296

if(ret == -1){

2297

perror_plus("setuid");

2298

}

3041

2299

3042

2300

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

3043

if(tempdir != NULL){

2301

if(tempdir_created){

3044

2302

struct dirent **direntries = NULL;

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

}

2303

struct dirent *direntry = NULL;

2304

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

2305

alphasort);

2306

if (numentries > 0){

2307

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

2308

direntry = direntries[i];

2309

char *fullname = NULL;

2310

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

2311

direntry->d_name);

2312

if(ret < 0){

2313

perror_plus("asprintf");

2314

continue;

2315

}

2316

ret = remove(fullname);

2317

if(ret == -1){

2318

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

2319

strerror(errno));

2320

}

2321

free(fullname);

3084

2322

}

3085

TEMP_FAILURE_RETRY(close(tempdir_fd));

2323

}

2324

2325

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

2326

free(direntries);

2327

if (numentries == -1){

2328

perror_plus("scandir");

2329

}

2330

ret = rmdir(tempdir);

2331

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

2332

perror_plus("rmdir");

3086

2333

}

3087

2334

}

3088

2335