/mandos/release : revision 237.7.147

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

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* 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

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#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(),

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stdout, ferror() */

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stdout, ferror(), remove() */

44

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

45

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

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

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strtof(), abort() */

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

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

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asprintf(), strncpy() */

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

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

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#include <sys/ioctl.h> /* ioctl */

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#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

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sockaddr_in6, PF_INET6,

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opendir(), DIR */

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#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(), AT_REMOVEDIR */

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inet_pton(), connect() */

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

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

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61

*/

63

62

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

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63

strtoimax() */

65

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

64

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

70

65

program_invocation_short_name */

71

66

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

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67

#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

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72

*/

78

73

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

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

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

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unlinkat() */

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

75

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

76

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

83

77

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

84

78

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

85

79

argp_state, struct argp,

97

91

argz_delete(), argz_append(),

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92

argz_stringify(), argz_add(),

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93

argz_count() */

100

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

101

EAI_SYSTEM, gai_strerror() */

102

94

103

95

#ifdef __linux__

104

96

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

146

138

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

147

139

char *connect_to = NULL;

148

140

const char *hookdir = HOOKDIR;

149

int hookdir_fd = -1;

150

141

uid_t uid = 65534;

151

142

gid_t gid = 65534;

152

143

163

154

164

155

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

165

156

typedef struct {

157

AvahiSimplePoll *simple_poll;

166

158

AvahiServer *server;

167

159

gnutls_certificate_credentials_t cred;

168

160

unsigned int dh_bits;

170

162

const char *priority;

171

163

gpgme_ctx_t ctx;

172

164

server *current_server;

173

char *interfaces;

174

size_t interfaces_size;

175

165

} mandos_context;

176

166

177

/* global so signal handler can reach it*/

178

AvahiSimplePoll *simple_poll;

167

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

168

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

169

.dh_bits = 1024, .priority = "SECURE256"

170

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

171

.current_server = NULL };

179

172

180

173

sig_atomic_t quit_now = 0;

181

174

int signal_received = 0;

189

182

perror(print_text);

190

183

}

191

184

192

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

185

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

193

186

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

194

187

va_list ap;

195

188

va_start (ap, format);

196

189

197

190

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

198

191

program_invocation_short_name));

199

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

192

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

200

193

}

201

194

202

195

/*

204

197

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

205

198

* "buffer_length" is how much is already used.

206

199

*/

207

__attribute__((nonnull, warn_unused_result))

208

200

size_t incbuffer(char **buffer, size_t buffer_length,

209

201

size_t buffer_capacity){

210

202

if(buffer_length + BUFFER_SIZE > buffer_capacity){

211

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

212

if(new_buf == NULL){

213

int old_errno = errno;

214

free(*buffer);

215

errno = old_errno;

216

*buffer = NULL;

203

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

204

if(buffer == NULL){

217

205

return 0;

218

206

}

219

*buffer = new_buf;

220

207

buffer_capacity += BUFFER_SIZE;

221

208

}

222

209

return buffer_capacity;

223

210

}

224

211

225

212

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

226

__attribute__((nonnull, warn_unused_result))

227

213

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

228

int af, server **current_server){

214

int af){

229

215

int ret;

230

216

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

231

217

if(new_server == NULL){

238

224

.af = af };

239

225

if(new_server->ip == NULL){

240

226

perror_plus("strdup");

241

free(new_server);

242

return false;

243

}

244

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

245

if(ret == -1){

246

perror_plus("clock_gettime");

247

#ifdef __GNUC__

248

#pragma GCC diagnostic push

249

#pragma GCC diagnostic ignored "-Wcast-qual"

250

#endif

251

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

252

#ifdef __GNUC__

253

#pragma GCC diagnostic pop

254

#endif

255

free(new_server);

256

227

return false;

257

228

}

258

229

/* Special case of first server */

259

if(*current_server == NULL){

230

if (mc.current_server == NULL){

260

231

new_server->next = new_server;

261

232

new_server->prev = new_server;

262

*current_server = new_server;

233

mc.current_server = new_server;

234

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

263

235

} else {

264

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

265

new_server->next = *current_server;

266

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

236

new_server->next = mc.current_server;

237

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

267

238

new_server->prev->next = new_server;

268

(*current_server)->prev = new_server;

239

mc.current_server->prev = new_server;

240

}

241

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

242

if(ret == -1){

243

perror_plus("clock_gettime");

244

return false;

269

245

}

270

246

return true;

271

247

}

273

249

/*

274

250

* Initialize GPGME.

275

251

*/

276

__attribute__((nonnull, warn_unused_result))

277

static bool init_gpgme(const char * const seckey,

278

const char * const pubkey,

279

const char * const tempdir,

280

mandos_context *mc){

252

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

253

const char *tempdir){

281

254

gpgme_error_t rc;

282

255

gpgme_engine_info_t engine_info;

283

256

257

284

258

/*

285

259

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

286

260

*/

287

bool import_key(const char * const filename){

261

bool import_key(const char *filename){

288

262

int ret;

289

263

int fd;

290

264

gpgme_data_t pgp_data;

302

276

return false;

303

277

}

304

278

305

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

279

rc = gpgme_op_import(mc.ctx, pgp_data);

306

280

if(rc != GPG_ERR_NO_ERROR){

307

281

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

308

282

gpgme_strsource(rc), gpgme_strerror(rc));

309

283

return false;

310

284

}

311

285

312

ret = close(fd);

286

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

313

287

if(ret == -1){

314

288

perror_plus("close");

315

289

}

352

326

}

353

327

354

328

/* Create new GPGME "context" */

355

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

329

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

356

330

if(rc != GPG_ERR_NO_ERROR){

357

331

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

358

332

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

371

345

* Decrypt OpenPGP data.

372

346

* Returns -1 on error

373

347

*/

374

__attribute__((nonnull, warn_unused_result))

375

348

static ssize_t pgp_packet_decrypt(const char *cryptotext,

376

349

size_t crypto_size,

377

char **plaintext,

378

mandos_context *mc){

350

char **plaintext){

379

351

gpgme_data_t dh_crypto, dh_plain;

380

352

gpgme_error_t rc;

381

353

ssize_t ret;

407

379

408

380

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

409

381

data buffer */

410

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

382

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

411

383

if(rc != GPG_ERR_NO_ERROR){

412

384

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

413

385

gpgme_strsource(rc), gpgme_strerror(rc));

414

386

plaintext_length = -1;

415

387

if(debug){

416

388

gpgme_decrypt_result_t result;

417

result = gpgme_op_decrypt_result(mc->ctx);

389

result = gpgme_op_decrypt_result(mc.ctx);

418

390

if(result == NULL){

419

391

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

420

392

} else {

497

469

return plaintext_length;

498

470

}

499

471

500

__attribute__((warn_unused_result, const))

501

static const char *safe_string(const char *str){

502

if(str == NULL)

503

return "(unknown)";

504

return str;

505

}

506

507

__attribute__((warn_unused_result))

508

static const char *safer_gnutls_strerror(int value){

472

static const char * safer_gnutls_strerror(int value){

509

473

const char *ret = gnutls_strerror(value);

510

return safe_string(ret);

474

if(ret == NULL)

475

ret = "(unknown)";

476

return ret;

511

477

}

512

478

513

479

/* GnuTLS log function callback */

514

__attribute__((nonnull))

515

480

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

516

481

const char* string){

517

482

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

518

483

}

519

484

520

__attribute__((nonnull(1, 2, 4), warn_unused_result))

521

485

static int init_gnutls_global(const char *pubkeyfilename,

522

const char *seckeyfilename,

523

const char *dhparamsfilename,

524

mandos_context *mc){

486

const char *seckeyfilename){

525

487

int ret;

526

unsigned int uret;

527

488

528

489

if(debug){

529

490

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

530

491

}

531

492

493

ret = gnutls_global_init();

494

if(ret != GNUTLS_E_SUCCESS){

495

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

496

safer_gnutls_strerror(ret));

497

return -1;

498

}

499

532

500

if(debug){

533

501

/* "Use a log level over 10 to enable all debugging options."

534

502

* - GnuTLS manual

538

506

}

539

507

540

508

/* OpenPGP credentials */

541

ret = gnutls_certificate_allocate_credentials(&mc->cred);

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

542

510

if(ret != GNUTLS_E_SUCCESS){

543

511

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

544

512

safer_gnutls_strerror(ret));

513

gnutls_global_deinit();

545

514

return -1;

546

515

}

547

516

553

522

}

554

523

555

524

ret = gnutls_certificate_set_openpgp_key_file

556

(mc->cred, pubkeyfilename, seckeyfilename,

525

(mc.cred, pubkeyfilename, seckeyfilename,

557

526

GNUTLS_OPENPGP_FMT_BASE64);

558

527

if(ret != GNUTLS_E_SUCCESS){

559

528

fprintf_plus(stderr,

565

534

}

566

535

567

536

/* GnuTLS server initialization */

568

ret = gnutls_dh_params_init(&mc->dh_params);

537

ret = gnutls_dh_params_init(&mc.dh_params);

569

538

if(ret != GNUTLS_E_SUCCESS){

570

539

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

571

540

" initialization: %s\n",

572

541

safer_gnutls_strerror(ret));

573

542

goto globalfail;

574

543

}

575

/* If a Diffie-Hellman parameters file was given, try to use it */

576

if(dhparamsfilename != NULL){

577

gnutls_datum_t params = { .data = NULL, .size = 0 };

578

do {

579

int dhpfile = open(dhparamsfilename, O_RDONLY);

580

if(dhpfile == -1){

581

perror_plus("open");

582

dhparamsfilename = NULL;

583

break;

584

}

585

size_t params_capacity = 0;

586

while(true){

587

params_capacity = incbuffer((char **)&params.data,

588

(size_t)params.size,

589

(size_t)params_capacity);

590

if(params_capacity == 0){

591

perror_plus("incbuffer");

592

free(params.data);

593

params.data = NULL;

594

dhparamsfilename = NULL;

595

break;

596

}

597

ssize_t bytes_read = read(dhpfile,

598

params.data + params.size,

599

BUFFER_SIZE);

600

/* EOF */

601

if(bytes_read == 0){

602

break;

603

}

604

/* check bytes_read for failure */

605

if(bytes_read < 0){

606

perror_plus("read");

607

free(params.data);

608

params.data = NULL;

609

dhparamsfilename = NULL;

610

break;

611

}

612

params.size += (unsigned int)bytes_read;

613

}

614

if(params.data == NULL){

615

dhparamsfilename = NULL;

616

}

617

if(dhparamsfilename == NULL){

618

break;

619

}

620

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

621

GNUTLS_X509_FMT_PEM);

622

if(ret != GNUTLS_E_SUCCESS){

623

fprintf_plus(stderr, "Failed to parse DH parameters in file"

624

" \"%s\": %s\n", dhparamsfilename,

625

safer_gnutls_strerror(ret));

626

dhparamsfilename = NULL;

627

}

628

} while(false);

629

}

630

if(dhparamsfilename == NULL){

631

if(mc->dh_bits == 0){

632

/* Find out the optimal number of DH bits */

633

/* Try to read the private key file */

634

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

635

do {

636

int secfile = open(seckeyfilename, O_RDONLY);

637

if(secfile == -1){

638

perror_plus("open");

639

break;

640

}

641

size_t buffer_capacity = 0;

642

while(true){

643

buffer_capacity = incbuffer((char **)&buffer.data,

644

(size_t)buffer.size,

645

(size_t)buffer_capacity);

646

if(buffer_capacity == 0){

647

perror_plus("incbuffer");

648

free(buffer.data);

649

buffer.data = NULL;

650

break;

651

}

652

ssize_t bytes_read = read(secfile,

653

buffer.data + buffer.size,

654

BUFFER_SIZE);

655

/* EOF */

656

if(bytes_read == 0){

657

break;

658

}

659

/* check bytes_read for failure */

660

if(bytes_read < 0){

661

perror_plus("read");

662

free(buffer.data);

663

buffer.data = NULL;

664

break;

665

}

666

buffer.size += (unsigned int)bytes_read;

667

}

668

close(secfile);

669

} while(false);

670

/* If successful, use buffer to parse private key */

671

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

672

if(buffer.data != NULL){

673

{

674

gnutls_openpgp_privkey_t privkey = NULL;

675

ret = gnutls_openpgp_privkey_init(&privkey);

676

if(ret != GNUTLS_E_SUCCESS){

677

fprintf_plus(stderr, "Error initializing OpenPGP key"

678

" structure: %s",

679

safer_gnutls_strerror(ret));

680

free(buffer.data);

681

buffer.data = NULL;

682

} else {

683

ret = gnutls_openpgp_privkey_import

684

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

685

if(ret != GNUTLS_E_SUCCESS){

686

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

687

safer_gnutls_strerror(ret));

688

privkey = NULL;

689

}

690

free(buffer.data);

691

buffer.data = NULL;

692

if(privkey != NULL){

693

/* Use private key to suggest an appropriate

694

sec_param */

695

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

696

gnutls_openpgp_privkey_deinit(privkey);

697

if(debug){

698

fprintf_plus(stderr, "This OpenPGP key implies using"

699

" a GnuTLS security parameter \"%s\".\n",

700

safe_string(gnutls_sec_param_get_name

701

(sec_param)));

702

}

703

}

704

}

705

}

706

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

707

/* Err on the side of caution */

708

sec_param = GNUTLS_SEC_PARAM_ULTRA;

709

if(debug){

710

fprintf_plus(stderr, "Falling back to security parameter"

711

" \"%s\"\n",

712

safe_string(gnutls_sec_param_get_name

713

(sec_param)));

714

}

715

}

716

}

717

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

718

if(uret != 0){

719

mc->dh_bits = uret;

720

if(debug){

721

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

722

" implies %u DH bits; using that.\n",

723

safe_string(gnutls_sec_param_get_name

724

(sec_param)),

725

mc->dh_bits);

726

}

727

} else {

728

fprintf_plus(stderr, "Failed to get implied number of DH"

729

" bits for security parameter \"%s\"): %s\n",

730

safe_string(gnutls_sec_param_get_name

731

(sec_param)),

732

safer_gnutls_strerror(ret));

733

goto globalfail;

734

}

735

} else if(debug){

736

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

737

mc->dh_bits);

738

}

739

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

740

if(ret != GNUTLS_E_SUCCESS){

741

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

742

" bits): %s\n", mc->dh_bits,

743

safer_gnutls_strerror(ret));

744

goto globalfail;

745

}

746

}

747

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

544

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

545

if(ret != GNUTLS_E_SUCCESS){

546

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

547

safer_gnutls_strerror(ret));

548

goto globalfail;

549

}

550

551

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

748

552

749

553

return 0;

750

554

751

555

globalfail:

752

556

753

gnutls_certificate_free_credentials(mc->cred);

754

gnutls_dh_params_deinit(mc->dh_params);

557

gnutls_certificate_free_credentials(mc.cred);

558

gnutls_global_deinit();

559

gnutls_dh_params_deinit(mc.dh_params);

755

560

return -1;

756

561

}

757

562

758

__attribute__((nonnull, warn_unused_result))

759

static int init_gnutls_session(gnutls_session_t *session,

760

mandos_context *mc){

563

static int init_gnutls_session(gnutls_session_t *session){

761

564

int ret;

762

565

/* GnuTLS session creation */

763

566

do {

775

578

{

776

579

const char *err;

777

580

do {

778

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

581

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

779

582

if(quit_now){

780

583

gnutls_deinit(*session);

781

584

return -1;

792

595

793

596

do {

794

597

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

795

mc->cred);

598

mc.cred);

796

599

if(quit_now){

797

600

gnutls_deinit(*session);

798

601

return -1;

808

611

/* ignore client certificate if any. */

809

612

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

810

613

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

615

811

616

return 0;

812

617

}

813

618

815

620

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

816

621

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

817

622

818

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

819

__attribute__((warn_unused_result))

820

int raise_privileges(void){

821

int old_errno = errno;

822

int ret = 0;

823

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

824

ret = errno;

825

}

826

errno = old_errno;

827

return ret;

828

}

829

830

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

831

__attribute__((warn_unused_result))

832

int raise_privileges_permanently(void){

833

int old_errno = errno;

834

int ret = raise_privileges();

835

if(ret != 0){

836

errno = old_errno;

837

return ret;

838

}

839

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

840

ret = errno;

841

}

842

errno = old_errno;

843

return ret;

844

}

845

846

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

847

__attribute__((warn_unused_result))

848

int lower_privileges(void){

849

int old_errno = errno;

850

int ret = 0;

851

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

852

ret = errno;

853

}

854

errno = old_errno;

855

return ret;

856

}

857

858

/* Lower privileges permanently */

859

__attribute__((warn_unused_result))

860

int lower_privileges_permanently(void){

861

int old_errno = errno;

862

int ret = 0;

863

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

864

ret = errno;

865

}

866

errno = old_errno;

867

return ret;

868

}

869

870

/* Helper function to add_local_route() and delete_local_route() */

871

__attribute__((nonnull, warn_unused_result))

872

static bool add_delete_local_route(const bool add,

873

const char *address,

874

AvahiIfIndex if_index){

875

int ret;

876

char helper[] = "mandos-client-iprouteadddel";

877

char add_arg[] = "add";

878

char delete_arg[] = "delete";

879

char debug_flag[] = "--debug";

880

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

881

if(pluginhelperdir == NULL){

882

if(debug){

883

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

884

" variable not set; cannot run helper\n");

885

}

886

return false;

887

}

888

889

char interface[IF_NAMESIZE];

890

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

891

perror_plus("if_indextoname");

892

return false;

893

}

894

895

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

896

if(devnull == -1){

897

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

898

return false;

899

}

900

pid_t pid = fork();

901

if(pid == 0){

902

/* Child */

903

/* Raise privileges */

904

errno = raise_privileges_permanently();

905

if(errno != 0){

906

perror_plus("Failed to raise privileges");

907

/* _exit(EX_NOPERM); */

908

} else {

909

/* Set group */

910

errno = 0;

911

ret = setgid(0);

912

if(ret == -1){

913

perror_plus("setgid");

914

_exit(EX_NOPERM);

915

}

916

/* Reset supplementary groups */

917

errno = 0;

918

ret = setgroups(0, NULL);

919

if(ret == -1){

920

perror_plus("setgroups");

921

_exit(EX_NOPERM);

922

}

923

}

924

ret = dup2(devnull, STDIN_FILENO);

925

if(ret == -1){

926

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

927

_exit(EX_OSERR);

928

}

929

ret = close(devnull);

930

if(ret == -1){

931

perror_plus("close");

932

_exit(EX_OSERR);

933

}

934

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

935

if(ret == -1){

936

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

937

_exit(EX_OSERR);

938

}

939

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

940

O_RDONLY

941

| O_DIRECTORY

942

| O_PATH

943

| O_CLOEXEC));

944

if(helperdir_fd == -1){

945

perror_plus("open");

946

_exit(EX_UNAVAILABLE);

947

}

948

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

949

helper, O_RDONLY));

950

if(helper_fd == -1){

951

perror_plus("openat");

952

close(helperdir_fd);

953

_exit(EX_UNAVAILABLE);

954

}

955

close(helperdir_fd);

956

#ifdef __GNUC__

957

#pragma GCC diagnostic push

958

#pragma GCC diagnostic ignored "-Wcast-qual"

959

#endif

960

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

961

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

962

interface, debug ? debug_flag : NULL, NULL },

963

environ) == -1){

964

#ifdef __GNUC__

965

#pragma GCC diagnostic pop

966

#endif

967

perror_plus("fexecve");

968

_exit(EXIT_FAILURE);

969

}

970

}

971

if(pid == -1){

972

perror_plus("fork");

973

return false;

974

}

975

int status;

976

pid_t pret = -1;

977

errno = 0;

978

do {

979

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

980

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

981

int errno_raising = 0;

982

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

983

errno_raising = errno;

984

perror_plus("Failed to raise privileges in order to"

985

" kill helper program");

986

}

987

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

988

perror_plus("kill");

989

}

990

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

991

perror_plus("Failed to lower privileges after killing"

992

" helper program");

993

}

994

return false;

995

}

996

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

997

if(pret == -1){

998

perror_plus("waitpid");

999

return false;

1000

}

1001

if(WIFEXITED(status)){

1002

if(WEXITSTATUS(status) != 0){

1003

fprintf_plus(stderr, "Error: iprouteadddel exited"

1004

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

1005

return false;

1006

}

1007

return true;

1008

}

1009

if(WIFSIGNALED(status)){

1010

fprintf_plus(stderr, "Error: iprouteadddel died by"

1011

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

1012

return false;

1013

}

1014

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

1015

return false;

1016

}

1017

1018

__attribute__((nonnull, warn_unused_result))

1019

static bool add_local_route(const char *address,

1020

AvahiIfIndex if_index){

1021

if(debug){

1022

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

1023

}

1024

return add_delete_local_route(true, address, if_index);

1025

}

1026

1027

__attribute__((nonnull, warn_unused_result))

1028

static bool delete_local_route(const char *address,

1029

AvahiIfIndex if_index){

1030

if(debug){

1031

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

1032

}

1033

return add_delete_local_route(false, address, if_index);

1034

}

1035

1036

623

/* Called when a Mandos server is found */

1037

__attribute__((nonnull, warn_unused_result))

1038

624

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

1039

625

AvahiIfIndex if_index,

1040

int af, mandos_context *mc){

626

int af){

1041

627

int ret, tcp_sd = -1;

1042

628

ssize_t sret;

1043

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1044

633

char *buffer = NULL;

1045

634

char *decrypted_buffer = NULL;

1046

635

size_t buffer_length = 0;

1049

638

int retval = -1;

1050

639

gnutls_session_t session;

1051

640

int pf; /* Protocol family */

1052

bool route_added = false;

1053

641

1054

642

errno = 0;

1055

643

1071

659

return -1;

1072

660

}

1073

661

1074

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

1075

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

1076

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

1077

bool match = false;

1078

{

1079

char *interface = NULL;

1080

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

1081

interface))){

1082

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

1083

match = true;

1084

break;

1085

}

1086

}

1087

}

1088

if(not match){

1089

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

1090

connect to the server */

1091

if(debug){

1092

char interface[IF_NAMESIZE];

1093

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

1094

perror_plus("if_indextoname");

1095

} else {

1096

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

1097

" \"%s\"\n",

1098

if_indextoname((unsigned int)if_index,

1099

interface));

1100

}

1101

}

1102

return -1;

1103

}

1104

}

1105

1106

ret = init_gnutls_session(&session, mc);

662

ret = init_gnutls_session(&session);

1107

663

if(ret != 0){

1108

664

return -1;

1109

665

}

1113

669

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

1114

670

}

1115

671

1116

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

672

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

673

if(tcp_sd < 0){

1118

674

int e = errno;

1119

675

perror_plus("socket");

1126

682

goto mandos_end;

1127

683

}

1128

684

685

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

1129

686

if(af == AF_INET6){

1130

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1131

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1132

ret = inet_pton(af, ip, &to6->sin6_addr);

687

to.in6.sin6_family = (sa_family_t)af;

688

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

1133

689

} else { /* IPv4 */

1134

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1135

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1136

ret = inet_pton(af, ip, &to4->sin_addr);

690

to.in.sin_family = (sa_family_t)af;

691

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

1137

692

}

1138

693

if(ret < 0 ){

1139

694

int e = errno;

1148

703

goto mandos_end;

1149

704

}

1150

705

if(af == AF_INET6){

1151

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

1152

if(IN6_IS_ADDR_LINKLOCAL

1153

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

706

to.in6.sin6_port = htons(port);

707

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

708

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

709

-Wunreachable-code*/

1154

710

if(if_index == AVAHI_IF_UNSPEC){

1155

711

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

1156

712

" incomplete without a network interface\n");

1158

714

goto mandos_end;

1159

715

}

1160

716

/* Set the network interface number as scope */

1161

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

717

to.in6.sin6_scope_id = (uint32_t)if_index;

1162

718

}

1163

719

} else {

1164

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

720

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

721

-Wconversion and

722

-Wunreachable-code */

1165

723

}

1166

724

1167

725

if(quit_now){

1184

742

}

1185

743

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1186

744

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1187

if(af == AF_INET6){

1188

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

1189

sizeof(struct sockaddr_in6),

1190

addrstr, sizeof(addrstr), NULL, 0,

1191

NI_NUMERICHOST);

1192

} else {

1193

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

1194

sizeof(struct sockaddr_in),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

}

1198

if(ret == EAI_SYSTEM){

1199

perror_plus("getnameinfo");

1200

} else if(ret != 0) {

1201

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

1202

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

1203

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

1204

}

1205

}

1206

1207

if(quit_now){

1208

errno = EINTR;

1209

goto mandos_end;

1210

}

1211

1212

while(true){

1213

if(af == AF_INET6){

1214

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

1215

sizeof(struct sockaddr_in6));

1216

} else {

1217

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

1218

sizeof(struct sockaddr_in));

1219

}

1220

if(ret < 0){

1221

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1222

and if_index != AVAHI_IF_UNSPEC

1223

and connect_to == NULL

1224

and not route_added and

1225

((af == AF_INET6 and not

1226

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1227

&to)->sin6_addr)))

1228

or (af == AF_INET and

1229

/* Not a a IPv4LL address */

1230

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

1231

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

1232

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

1233

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

1234

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

1235

connect to a Mandos server announced by Avahi on a server

1236

host with a global address. Work around this by retrying

1237

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

1238

1239

Avahi bug reference:

1240

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

1241

https://bugs.debian.org/587961

1242

*/

1243

if(debug){

1244

fprintf_plus(stderr, "Mandos server unreachable, trying"

1245

" direct route\n");

1246

}

1247

int e = errno;

1248

route_added = add_local_route(ip, if_index);

1249

if(route_added){

1250

continue;

1251

}

1252

errno = e;

1253

}

1254

if(errno != ECONNREFUSED or debug){

1255

int e = errno;

1256

perror_plus("connect");

1257

errno = e;

1258

}

1259

goto mandos_end;

1260

}

1261

1262

if(quit_now){

1263

errno = EINTR;

1264

goto mandos_end;

1265

}

1266

break;

745

const char *pcret;

746

if(af == AF_INET6){

747

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

748

sizeof(addrstr));

749

} else {

750

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

751

sizeof(addrstr));

752

}

753

if(pcret == NULL){

754

perror_plus("inet_ntop");

755

} else {

756

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

757

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

758

}

759

}

760

}

761

762

if(quit_now){

763

errno = EINTR;

764

goto mandos_end;

765

}

766

767

if(af == AF_INET6){

768

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

769

} else {

770

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

771

}

772

if(ret < 0){

773

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

774

int e = errno;

775

perror_plus("connect");

776

errno = e;

777

}

778

goto mandos_end;

779

}

780

781

if(quit_now){

782

errno = EINTR;

783

goto mandos_end;

1267

784

}

1268

785

1269

786

const char *out = mandos_protocol_version;

1420

937

if(buffer_length > 0){

1421

938

ssize_t decrypted_buffer_size;

1422

939

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1423

&decrypted_buffer, mc);

940

&decrypted_buffer);

1424

941

if(decrypted_buffer_size >= 0){

1425

942

1426

943

written = 0;

1452

969

1453

970

mandos_end:

1454

971

{

1455

if(route_added){

1456

if(not delete_local_route(ip, if_index)){

1457

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

1458

" interface %d", ip, if_index);

1459

}

1460

}

1461

972

int e = errno;

1462

973

free(decrypted_buffer);

1463

974

free(buffer);

1464

975

if(tcp_sd >= 0){

1465

ret = close(tcp_sd);

976

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

1466

977

}

1467

978

if(ret == -1){

1468

979

if(e == 0){

1480

991

return retval;

1481

992

}

1482

993

1483

__attribute__((nonnull))

1484

994

static void resolve_callback(AvahiSServiceResolver *r,

1485

995

AvahiIfIndex interface,

1486

996

AvahiProtocol proto,

1494

1004

AVAHI_GCC_UNUSED AvahiStringList *txt,

1495

1005

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1496

1006

flags,

1497

void *mc){

1007

AVAHI_GCC_UNUSED void* userdata){

1498

1008

if(r == NULL){

1499

1009

return;

1500

1010

}

1503

1013

timed out */

1504

1014

1505

1015

if(quit_now){

1506

avahi_s_service_resolver_free(r);

1507

1016

return;

1508

1017

}

1509

1018

1513

1022

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

1514

1023

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

1515

1024

domain,

1516

avahi_strerror(avahi_server_errno

1517

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

1025

avahi_strerror(avahi_server_errno(mc.server)));

1518

1026

break;

1519

1027

1520

1028

case AVAHI_RESOLVER_FOUND:

1528

1036

}

1529

1037

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

1530

1038

interface,

1531

avahi_proto_to_af(proto),

1532

mc);

1039

avahi_proto_to_af(proto));

1533

1040

if(ret == 0){

1534

avahi_simple_poll_quit(simple_poll);

1041

avahi_simple_poll_quit(mc.simple_poll);

1535

1042

} else {

1536

1043

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

1537

avahi_proto_to_af(proto),

1538

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

1044

avahi_proto_to_af(proto))){

1539

1045

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

1540

1046

" list\n", name);

1541

1047

}

1554

1060

const char *domain,

1555

1061

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1556

1062

flags,

1557

void *mc){

1063

AVAHI_GCC_UNUSED void* userdata){

1558

1064

if(b == NULL){

1559

1065

return;

1560

1066

}

1571

1077

case AVAHI_BROWSER_FAILURE:

1572

1078

1573

1079

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

1574

avahi_strerror(avahi_server_errno

1575

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

1576

avahi_simple_poll_quit(simple_poll);

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1577

1082

return;

1578

1083

1579

1084

case AVAHI_BROWSER_NEW:

1582

1087

the callback function is called the Avahi server will free the

1583

1088

resolver for us. */

1584

1089

1585

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

1586

interface, protocol, name, type,

1587

domain, protocol, 0,

1588

resolve_callback, mc) == NULL)

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1589

1093

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

1590

1094

" %s\n", name,

1591

avahi_strerror(avahi_server_errno

1592

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

1095

avahi_strerror(avahi_server_errno(mc.server)));

1593

1096

break;

1594

1097

1595

1098

case AVAHI_BROWSER_REMOVE:

1614

1117

signal_received = sig;

1615

1118

int old_errno = errno;

1616

1119

/* set main loop to exit */

1617

if(simple_poll != NULL){

1618

avahi_simple_poll_quit(simple_poll);

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1619

1122

}

1620

1123

errno = old_errno;

1621

1124

}

1622

1125

1623

__attribute__((nonnull, warn_unused_result))

1624

1126

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

1625

1127

int ret;

1626

int old_errno;

1128

error_t ret_errno;

1627

1129

1628

1130

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

1629

1131

if(s < 0){

1630

old_errno = errno;

1132

ret_errno = errno;

1631

1133

perror_plus("socket");

1632

errno = old_errno;

1134

errno = ret_errno;

1633

1135

return false;

1634

1136

}

1635

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1636

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1137

strcpy(ifr->ifr_name, ifname);

1637

1138

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1638

1139

if(ret == -1){

1639

1140

if(debug){

1640

old_errno = errno;

1141

ret_errno = errno;

1641

1142

perror_plus("ioctl SIOCGIFFLAGS");

1642

errno = old_errno;

1143

errno = ret_errno;

1643

1144

}

1644

1145

return false;

1645

1146

}

1646

1147

return true;

1647

1148

}

1648

1149

1649

__attribute__((nonnull, warn_unused_result))

1650

1150

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

1651

1151

1652

1152

/* Reject the loopback device */

1694

1194

* corresponds to an acceptable network device.

1695

1195

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

1696

1196

*/

1697

__attribute__((nonnull, warn_unused_result))

1698

1197

int good_interface(const struct dirent *if_entry){

1699

1198

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

1700

1199

return 0;

1718

1217

/*

1719

1218

* This function determines if a network interface is up.

1720

1219

*/

1721

__attribute__((nonnull, warn_unused_result))

1722

1220

bool interface_is_up(const char *interface){

1723

1221

struct ifreq ifr;

1724

1222

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

1735

1233

/*

1736

1234

* This function determines if a network interface is running

1737

1235

*/

1738

__attribute__((nonnull, warn_unused_result))

1739

1236

bool interface_is_running(const char *interface){

1740

1237

struct ifreq ifr;

1741

1238

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

1749

1246

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

1750

1247

}

1751

1248

1752

__attribute__((nonnull, pure, warn_unused_result))

1753

1249

int notdotentries(const struct dirent *direntry){

1754

1250

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

1755

1251

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

1762

1258

}

1763

1259

1764

1260

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

1765

__attribute__((nonnull, warn_unused_result))

1766

1261

int runnable_hook(const struct dirent *direntry){

1767

1262

int ret;

1768

1263

size_t sret;

1776

1271

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

1777

1272

"abcdefghijklmnopqrstuvwxyz"

1778

1273

"0123456789"

1779

"_.-");

1274

"_-");

1780

1275

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

1781

1276

/* Contains non-allowed characters */

1782

1277

if(debug){

1786

1281

return 0;

1787

1282

}

1788

1283

1789

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);

1790

1292

if(ret == -1){

1791

1293

if(debug){

1792

1294

perror_plus("Could not stat hook");

1816

1318

return 1;

1817

1319

}

1818

1320

1819

__attribute__((nonnull, warn_unused_result))

1820

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1821

mandos_context *mc){

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1822

1322

int ret;

1823

1323

struct timespec now;

1824

1324

struct timespec waited_time;

1825

1325

intmax_t block_time;

1826

1326

1827

1327

while(true){

1828

if(mc->current_server == NULL){

1829

if(debug){

1328

if(mc.current_server == NULL){

1329

if (debug){

1830

1330

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

1831

1331

" No timeout!\n");

1832

1332

}

1833

1333

ret = avahi_simple_poll_iterate(s, -1);

1834

1334

} else {

1835

if(debug){

1335

if (debug){

1836

1336

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

1837

1337

" it, or wait\n");

1838

1338

}

1845

1345

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

1846

1346

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

1847

1347

waited_time.tv_sec = (now.tv_sec

1848

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

1348

- mc.current_server->last_seen.tv_sec);

1849

1349

waited_time.tv_nsec = (now.tv_nsec

1850

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

1350

- mc.current_server->last_seen.tv_nsec);

1851

1351

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

1852

1352

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

1853

1353

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

1855

1355

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

1856

1356

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

1857

1357

1858

if(debug){

1358

if (debug){

1859

1359

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

1860

1360

block_time);

1861

1361

}

1862

1362

1863

1363

if(block_time <= 0){

1864

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

1865

mc->current_server->port,

1866

mc->current_server->if_index,

1867

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);

1868

1368

if(ret == 0){

1869

avahi_simple_poll_quit(s);

1369

avahi_simple_poll_quit(mc.simple_poll);

1870

1370

return 0;

1871

1371

}

1872

1372

ret = clock_gettime(CLOCK_MONOTONIC,

1873

&mc->current_server->last_seen);

1373

&mc.current_server->last_seen);

1874

1374

if(ret == -1){

1875

1375

perror_plus("clock_gettime");

1876

1376

return -1;

1877

1377

}

1878

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

1378

mc.current_server = mc.current_server->next;

1879

1379

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

1880

1380

servers, but don't block */

1881

1381

}

1883

1383

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

1884

1384

}

1885

1385

if(ret != 0){

1886

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

1386

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

1887

1387

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

1888

1388

}

1889

1389

}

1890

1390

}

1891

1391

}

1892

1392

1893

__attribute__((nonnull))

1894

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

1393

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

1394

error_t raise_privileges(void){

1395

error_t old_errno = errno;

1396

error_t ret_errno = 0;

1397

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

1398

ret_errno = errno;

1399

perror_plus("seteuid");

1400

}

1401

errno = old_errno;

1402

return ret_errno;

1403

}

1404

1405

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

1406

error_t raise_privileges_permanently(void){

1407

error_t old_errno = errno;

1408

error_t ret_errno = raise_privileges();

1409

if(ret_errno != 0){

1410

errno = old_errno;

1411

return ret_errno;

1412

}

1413

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

1414

ret_errno = errno;

1415

perror_plus("seteuid");

1416

}

1417

errno = old_errno;

1418

return ret_errno;

1419

}

1420

1421

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

1422

error_t lower_privileges(void){

1423

error_t old_errno = errno;

1424

error_t ret_errno = 0;

1425

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

1426

ret_errno = errno;

1427

perror_plus("seteuid");

1428

}

1429

errno = old_errno;

1430

return ret_errno;

1431

}

1432

1433

/* Lower privileges permanently */

1434

error_t lower_privileges_permanently(void){

1435

error_t old_errno = errno;

1436

error_t ret_errno = 0;

1437

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

1438

ret_errno = errno;

1439

perror_plus("setuid");

1440

}

1441

errno = old_errno;

1442

return ret_errno;

1443

}

1444

1445

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

1895

1446

const float delay){

1896

struct dirent **direntries = NULL;

1897

if(hookdir_fd == -1){

1898

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1899

| O_CLOEXEC);

1900

if(hookdir_fd == -1){

1901

if(errno == ENOENT){

1902

if(debug){

1903

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

1904

" found\n", hookdir);

1905

}

1906

} else {

1907

perror_plus("open");

1908

}

1909

return;

1910

}

1911

}

1912

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

1913

runnable_hook, alphasort);

1447

struct dirent **direntries;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

1914

1452

if(numhooks == -1){

1915

perror_plus("scandir");

1916

return;

1917

}

1918

struct dirent *direntry;

1919

int ret;

1920

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

1921

if(devnull == -1){

1922

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

1923

return;

1924

}

1925

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

1926

direntry = direntries[i];

1927

if(debug){

1928

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

1929

direntry->d_name);

1453

if(errno == ENOENT){

1454

if(debug){

1455

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

1456

" found\n", hookdir);

1457

}

1458

} else {

1459

perror_plus("scandir");

1930

1460

}

1931

pid_t hook_pid = fork();

1932

if(hook_pid == 0){

1933

/* Child */

1934

/* Raise privileges */

1935

errno = raise_privileges_permanently();

1936

if(errno != 0){

1937

perror_plus("Failed to raise privileges");

1938

_exit(EX_NOPERM);

1939

}

1940

/* Set group */

1941

errno = 0;

1942

ret = setgid(0);

1943

if(ret == -1){

1944

perror_plus("setgid");

1945

_exit(EX_NOPERM);

1946

}

1947

/* Reset supplementary groups */

1948

errno = 0;

1949

ret = setgroups(0, NULL);

1950

if(ret == -1){

1951

perror_plus("setgroups");

1952

_exit(EX_NOPERM);

1953

}

1954

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

1955

if(ret == -1){

1956

perror_plus("setenv");

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("setenv");

1962

_exit(EX_OSERR);

1963

}

1964

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

1965

if(ret == -1){

1966

perror_plus("setenv");

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

if(ret == -1){

1971

perror_plus("setenv");

1972

_exit(EX_OSERR);

1973

}

1974

char *delaystring;

1975

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

1976

if(ret == -1){

1461

} else {

1462

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

1463

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

1464

direntry = direntries[i];

1465

char *fullname = NULL;

1466

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

1467

if(ret < 0){

1977

1468

perror_plus("asprintf");

1978

_exit(EX_OSERR);

1979

}

1980

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

1981

if(ret == -1){

1469

continue;

1470

}

1471

if(debug){

1472

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

1473

direntry->d_name);

1474

}

1475

pid_t hook_pid = fork();

1476

if(hook_pid == 0){

1477

/* Child */

1478

/* Raise privileges */

1479

raise_privileges_permanently();

1480

/* Set group */

1481

errno = 0;

1482

ret = setgid(0);

1483

if(ret == -1){

1484

perror_plus("setgid");

1485

}

1486

/* Reset supplementary groups */

1487

errno = 0;

1488

ret = setgroups(0, NULL);

1489

if(ret == -1){

1490

perror_plus("setgroups");

1491

}

1492

dup2(devnull, STDIN_FILENO);

1493

close(devnull);

1494

dup2(STDERR_FILENO, STDOUT_FILENO);

1495

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

1496

if(ret == -1){

1497

perror_plus("setenv");

1498

_exit(EX_OSERR);

1499

}

1500

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

1501

if(ret == -1){

1502

perror_plus("setenv");

1503

_exit(EX_OSERR);

1504

}

1505

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

1506

if(ret == -1){

1507

perror_plus("setenv");

1508

_exit(EX_OSERR);

1509

}

1510

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

1511

if(ret == -1){

1512

perror_plus("setenv");

1513

_exit(EX_OSERR);

1514

}

1515

char *delaystring;

1516

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

1517

if(ret == -1){

1518

perror_plus("asprintf");

1519

_exit(EX_OSERR);

1520

}

1521

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

1522

if(ret == -1){

1523

free(delaystring);

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1982

1527

free(delaystring);

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

free(delaystring);

1987

if(connect_to != NULL){

1988

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

1989

if(ret == -1){

1990

perror_plus("setenv");

1991

_exit(EX_OSERR);

1992

}

1993

}

1994

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

1995

direntry->d_name,

1996

O_RDONLY));

1997

if(hook_fd == -1){

1998

perror_plus("openat");

1999

_exit(EXIT_FAILURE);

2000

}

2001

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

2002

perror_plus("close");

2003

_exit(EXIT_FAILURE);

2004

}

2005

ret = dup2(devnull, STDIN_FILENO);

2006

if(ret == -1){

2007

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

2008

_exit(EX_OSERR);

2009

}

2010

ret = close(devnull);

2011

if(ret == -1){

2012

perror_plus("close");

2013

_exit(EX_OSERR);

2014

}

2015

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2016

if(ret == -1){

2017

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

2018

_exit(EX_OSERR);

2019

}

2020

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

2021

environ) == -1){

2022

perror_plus("fexecve");

2023

_exit(EXIT_FAILURE);

2024

}

2025

} else {

2026

if(hook_pid == -1){

2027

perror_plus("fork");

2028

free(direntry);

2029

continue;

2030

}

2031

int status;

2032

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

2033

perror_plus("waitpid");

2034

free(direntry);

2035

continue;

2036

}

2037

if(WIFEXITED(status)){

2038

if(WEXITSTATUS(status) != 0){

2039

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

2040

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

2041

WEXITSTATUS(status));

2042

free(direntry);

2043

continue;

2044

}

2045

} else if(WIFSIGNALED(status)){

2046

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

2047

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

2048

WTERMSIG(status));

2049

free(direntry);

2050

continue;

1528

if(connect_to != NULL){

1529

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

1530

if(ret == -1){

1531

perror_plus("setenv");

1532

_exit(EX_OSERR);

1533

}

1534

}

1535

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

1536

perror_plus("execl");

1537

_exit(EXIT_FAILURE);

1538

}

2051

1539

} else {

2052

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

2053

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

2054

free(direntry);

2055

continue;

2056

}

2057

}

2058

if(debug){

2059

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

2060

direntry->d_name);

2061

}

2062

free(direntry);

2063

}

2064

free(direntries);

2065

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

2066

perror_plus("close");

2067

} else {

2068

hookdir_fd = -1;

2069

}

2070

close(devnull);

1540

int status;

1541

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

1542

perror_plus("waitpid");

1543

free(fullname);

1544

continue;

1545

}

1546

if(WIFEXITED(status)){

1547

if(WEXITSTATUS(status) != 0){

1548

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

1549

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

1550

WEXITSTATUS(status));

1551

free(fullname);

1552

continue;

1553

}

1554

} else if(WIFSIGNALED(status)){

1555

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

1556

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

1557

WTERMSIG(status));

1558

free(fullname);

1559

continue;

1560

} else {

1561

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

1562

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

1563

free(fullname);

1564

continue;

1565

}

1566

}

1567

free(fullname);

1568

if(debug){

1569

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

1570

direntry->d_name);

1571

}

1572

}

1573

close(devnull);

1574

}

1575

return true;

2071

1576

}

2072

1577

2073

__attribute__((nonnull, warn_unused_result))

2074

int bring_up_interface(const char *const interface,

2075

const float delay){

2076

int old_errno = errno;

2077

int ret;

1578

error_t bring_up_interface(const char *const interface,

1579

const float delay){

1580

int sd = -1;

1581

error_t old_errno = errno;

1582

error_t ret_errno = 0;

1583

int ret, ret_setflags;

2078

1584

struct ifreq network;

2079

1585

unsigned int if_index = if_nametoindex(interface);

2080

1586

if(if_index == 0){

2089

1595

}

2090

1596

2091

1597

if(not interface_is_up(interface)){

2092

int ret_errno = 0;

2093

int ioctl_errno = 0;

2094

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

1598

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

2095

1599

ret_errno = errno;

2096

1600

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

2097

1601

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

2098

errno = old_errno;

2099

1602

return ret_errno;

2100

1603

}

2101

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

1604

network.ifr_flags |= IFF_UP;

2102

1605

2103

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

2104

if(sd == -1){

1606

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1607

if(sd < 0){

2105

1608

ret_errno = errno;

2106

1609

perror_plus("socket");

2107

1610

errno = old_errno;

2108

1611

return ret_errno;

2109

1612

}

2110

1613

2111

1614

if(quit_now){

2112

ret = close(sd);

2113

if(ret == -1){

2114

perror_plus("close");

2115

}

1615

close(sd);

2116

1616

errno = old_errno;

2117

1617

return EINTR;

2118

1618

}

2122

1622

interface);

2123

1623

}

2124

1624

2125

/* Raise privileges */

2126

ret_errno = raise_privileges();

2127

if(ret_errno != 0){

2128

errno = ret_errno;

2129

perror_plus("Failed to raise privileges");

2130

}

1625

/* Raise priviliges */

1626

raise_privileges();

2131

1627

2132

1628

#ifdef __linux__

2133

int ret_linux;

2134

bool restore_loglevel = false;

2135

if(ret_errno == 0){

2136

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2137

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

2138

ret_linux = klogctl(8, NULL, 5);

2139

if(ret_linux == -1){

2140

perror_plus("klogctl");

2141

} else {

2142

restore_loglevel = true;

2143

}

1629

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1630

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

1631

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

1632

bool restore_loglevel = true;

1633

if(ret_linux == -1){

1634

restore_loglevel = false;

1635

perror_plus("klogctl");

2144

1636

}

2145

1637

#endif /* __linux__ */

2146

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

2147

ioctl_errno = errno;

1638

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

1639

ret_errno = errno;

2148

1640

#ifdef __linux__

2149

1641

if(restore_loglevel){

2150

1642

ret_linux = klogctl(7, NULL, 0);

2154

1646

}

2155

1647

#endif /* __linux__ */

2156

1648

2157

/* If raise_privileges() succeeded above */

2158

if(ret_errno == 0){

2159

/* Lower privileges */

2160

ret_errno = lower_privileges();

2161

if(ret_errno != 0){

2162

errno = ret_errno;

2163

perror_plus("Failed to lower privileges");

2164

}

2165

}

1649

/* Lower privileges */

1650

lower_privileges();

2166

1651

2167

1652

/* Close the socket */

2168

ret = close(sd);

1653

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

2169

1654

if(ret == -1){

2170

1655

perror_plus("close");

2171

1656

}

2172

1657

2173

1658

if(ret_setflags == -1){

2174

errno = ioctl_errno;

1659

errno = ret_errno;

2175

1660

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2176

1661

errno = old_errno;

2177

return ioctl_errno;

1662

return ret_errno;

2178

1663

}

2179

1664

} else if(debug){

2180

1665

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

2198

1683

return 0;

2199

1684

}

2200

1685

2201

__attribute__((nonnull, warn_unused_result))

2202

int take_down_interface(const char *const interface){

2203

int old_errno = errno;

1686

error_t take_down_interface(const char *const interface){

1687

int sd = -1;

1688

error_t old_errno = errno;

1689

error_t ret_errno = 0;

1690

int ret, ret_setflags;

2204

1691

struct ifreq network;

2205

1692

unsigned int if_index = if_nametoindex(interface);

2206

1693

if(if_index == 0){

2209

1696

return ENXIO;

2210

1697

}

2211

1698

if(interface_is_up(interface)){

2212

int ret_errno = 0;

2213

int ioctl_errno = 0;

2214

1699

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

2215

1700

ret_errno = errno;

2216

1701

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

2217

1702

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

2218

errno = old_errno;

2219

1703

return ret_errno;

2220

1704

}

2221

1705

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

2222

1706

2223

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

2224

if(sd == -1){

1707

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1708

if(sd < 0){

2225

1709

ret_errno = errno;

2226

1710

perror_plus("socket");

2227

1711

errno = old_errno;

2233

1717

interface);

2234

1718

}

2235

1719

2236

/* Raise privileges */

2237

ret_errno = raise_privileges();

2238

if(ret_errno != 0){

2239

errno = ret_errno;

2240

perror_plus("Failed to raise privileges");

2241

}

2242

2243

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

2244

ioctl_errno = errno;

2245

2246

/* If raise_privileges() succeeded above */

2247

if(ret_errno == 0){

2248

/* Lower privileges */

2249

ret_errno = lower_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to lower privileges");

2253

}

2254

}

1720

/* Raise priviliges */

1721

raise_privileges();

1722

1723

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

1724

ret_errno = errno;

1725

1726

/* Lower privileges */

1727

lower_privileges();

2255

1728

2256

1729

/* Close the socket */

2257

int ret = close(sd);

1730

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

2258

1731

if(ret == -1){

2259

1732

perror_plus("close");

2260

1733

}

2261

1734

2262

1735

if(ret_setflags == -1){

2263

errno = ioctl_errno;

1736

errno = ret_errno;

2264

1737

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2265

1738

errno = old_errno;

2266

return ioctl_errno;

1739

return ret_errno;

2267

1740

}

2268

1741

} else if(debug){

2269

1742

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

2275

1748

}

2276

1749

2277

1750

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

2278

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

2279

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

2280

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2281

.current_server = NULL, .interfaces = NULL,

2282

.interfaces_size = 0 };

2283

1751

AvahiSServiceBrowser *sb = NULL;

2284

1752

error_t ret_errno;

2285

1753

int ret;

2286

1754

intmax_t tmpmax;

2287

1755

char *tmp;

2288

1756

int exitcode = EXIT_SUCCESS;

1757

char *interfaces = NULL;

1758

size_t interfaces_size = 0;

2289

1759

char *interfaces_to_take_down = NULL;

2290

1760

size_t interfaces_to_take_down_size = 0;

2291

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

2292

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

2293

char *tempdir = NULL;

1761

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

1762

bool tempdir_created = false;

2294

1763

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2295

1764

const char *seckey = PATHDIR "/" SECKEY;

2296

1765

const char *pubkey = PATHDIR "/" PUBKEY;

2297

const char *dh_params_file = NULL;

2298

1766

char *interfaces_hooks = NULL;

1767

size_t interfaces_hooks_size = 0;

2299

1768

2300

1769

bool gnutls_initialized = false;

2301

1770

bool gpgme_initialized = false;

2353

1822

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

2354

1823

" Diffie-Hellman key exchange",

2355

1824

.group = 2 },

2356

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

2357

.arg = "FILE",

2358

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

2359

" for the Diffie-Hellman key exchange",

2360

.group = 2 },

2361

1825

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

2362

1826

.arg = "STRING",

2363

1827

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

2397

1861

connect_to = arg;

2398

1862

break;

2399

1863

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

2400

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

2401

arg, (int)',');

1864

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

1865

(int)',');

2402

1866

if(ret_errno != 0){

2403

1867

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

2404

1868

}

2418

1882

}

2419

1883

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

2420

1884

break;

2421

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

2422

dh_params_file = arg;

2423

break;

2424

1885

case 130: /* --priority */

2425

1886

mc.priority = arg;

2426

1887

break;

2466

1927

.args_doc = "",

2467

1928

.doc = "Mandos client -- Get and decrypt"

2468

1929

" passwords from a Mandos server" };

2469

ret_errno = argp_parse(&argp, argc, argv,

2470

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2471

switch(ret_errno){

1930

ret = argp_parse(&argp, argc, argv,

1931

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1932

switch(ret){

2472

1933

case 0:

2473

1934

break;

2474

1935

case ENOMEM:

2475

1936

default:

2476

errno = ret_errno;

1937

errno = ret;

2477

1938

perror_plus("argp_parse");

2478

1939

exitcode = EX_OSERR;

2479

1940

goto end;

2482

1943

goto end;

2483

1944

}

2484

1945

}

2485

1946

2486

1947

{

2487

1948

/* Work around Debian bug #633582:

2488

1949

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

2489

1950

2490

/* Re-raise privileges */

2491

ret = raise_privileges();

2492

if(ret != 0){

2493

errno = ret;

2494

perror_plus("Failed to raise privileges");

2495

} else {

1951

/* Re-raise priviliges */

1952

if(raise_privileges() == 0){

2496

1953

struct stat st;

2497

1954

2498

1955

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

2512

1969

}

2513

1970

}

2514

1971

}

2515

close(seckey_fd);

1972

TEMP_FAILURE_RETRY(close(seckey_fd));

2516

1973

}

2517

1974

}

2518

1975

2519

1976

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

2520

1977

int pubkey_fd = open(pubkey, O_RDONLY);

2521

1978

if(pubkey_fd == -1){

2533

1990

}

2534

1991

}

2535

1992

}

2536

close(pubkey_fd);

2537

}

2538

}

2539

2540

if(dh_params_file != NULL

2541

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

2542

int dhparams_fd = open(dh_params_file, O_RDONLY);

2543

if(dhparams_fd == -1){

2544

perror_plus("open");

2545

} else {

2546

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

2547

if(ret == -1){

2548

perror_plus("fstat");

2549

} else {

2550

if(S_ISREG(st.st_mode)

2551

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

2552

ret = fchown(dhparams_fd, uid, gid);

2553

if(ret == -1){

2554

perror_plus("fchown");

2555

}

2556

}

2557

}

2558

close(dhparams_fd);

2559

}

2560

}

2561

1993

TEMP_FAILURE_RETRY(close(pubkey_fd));

1994

}

1995

}

1996

2562

1997

/* Lower privileges */

2563

ret = lower_privileges();

2564

if(ret != 0){

2565

errno = ret;

2566

perror_plus("Failed to lower privileges");

1998

errno = 0;

1999

ret = seteuid(uid);

2000

if(ret == -1){

2001

perror_plus("seteuid");

2567

2002

}

2568

2003

}

2569

2004

}

2570

2005

2571

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

2006

/* Remove empty interface names */

2572

2007

{

2573

2008

char *interface = NULL;

2574

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

2009

while((interface = argz_next(interfaces, interfaces_size,

2575

2010

interface))){

2576

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

2577

and if_nametoindex(interface) == 0){

2578

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

2011

if(if_nametoindex(interface) == 0){

2012

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

2579

2013

fprintf_plus(stderr, "Not using nonexisting interface"

2580

2014

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

2581

2015

}

2582

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

2016

argz_delete(&interfaces, &interfaces_size, interface);

2583

2017

interface = NULL;

2584

2018

}

2585

2019

}

2587

2021

2588

2022

/* Run network hooks */

2589

2023

{

2590

if(mc.interfaces != NULL){

2591

interfaces_hooks = malloc(mc.interfaces_size);

2024

2025

if(interfaces != NULL){

2026

interfaces_hooks = malloc(interfaces_size);

2592

2027

if(interfaces_hooks == NULL){

2593

2028

perror_plus("malloc");

2594

2029

goto end;

2595

2030

}

2596

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

2597

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

2598

}

2599

run_network_hooks("start", interfaces_hooks != NULL ?

2600

interfaces_hooks : "", delay);

2031

memcpy(interfaces_hooks, interfaces, interfaces_size);

2032

interfaces_hooks_size = interfaces_size;

2033

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2034

(int)',');

2035

}

2036

if(not run_network_hooks("start", interfaces_hooks != NULL ?

2037

interfaces_hooks : "", delay)){

2038

goto end;

2039

}

2601

2040

}

2602

2041

2603

2042

if(not debug){

2608

2047

from the signal handler */

2609

2048

/* Initialize the pseudo-RNG for Avahi */

2610

2049

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

2611

simple_poll = avahi_simple_poll_new();

2612

if(simple_poll == NULL){

2050

mc.simple_poll = avahi_simple_poll_new();

2051

if(mc.simple_poll == NULL){

2613

2052

fprintf_plus(stderr,

2614

2053

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

2615

2054

exitcode = EX_UNAVAILABLE;

2680

2119

}

2681

2120

2682

2121

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

2683

if(mc.interfaces == NULL){

2684

struct dirent **direntries = NULL;

2122

if(interfaces == NULL){

2123

struct dirent **direntries;

2685

2124

/* Look for any good interfaces */

2686

2125

ret = scandir(sys_class_net, &direntries, good_interface,

2687

2126

alphasort);

2688

2127

if(ret >= 1){

2689

2128

/* Add all found interfaces to interfaces list */

2690

2129

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

2691

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

2130

ret_errno = argz_add(&interfaces, &interfaces_size,

2692

2131

direntries[i]->d_name);

2693

2132

if(ret_errno != 0){

2694

errno = ret_errno;

2695

2133

perror_plus("argz_add");

2696

free(direntries[i]);

2697

2134

continue;

2698

2135

}

2699

2136

if(debug){

2700

2137

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

2701

2138

direntries[i]->d_name);

2702

2139

}

2703

free(direntries[i]);

2704

2140

}

2705

2141

free(direntries);

2706

2142

} else {

2707

if(ret == 0){

2708

free(direntries);

2709

}

2143

free(direntries);

2710

2144

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

2711

2145

exitcode = EXIT_FAILURE;

2712

2146

goto end;

2713

2147

}

2714

2148

}

2715

2149

2716

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

2717

{

2150

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

2151

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

2152

if(debug){

2153

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

2154

interfaces);

2155

}

2156

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2157

}

2158

2159

/* Bring up interfaces which are down */

2160

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

2161

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

2718

2162

char *interface = NULL;

2719

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

2163

while((interface = argz_next(interfaces, interfaces_size,

2720

2164

interface))){

2721

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

2722

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

2723

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

2724

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

2725

interface);

2726

interface = NULL;

2727

while((interface = argz_next(mc.interfaces,

2728

mc.interfaces_size, interface))){

2729

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

2730

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

2731

interface);

2732

interface = NULL;

2733

}

2734

}

2735

break;

2736

}

2737

2165

bool interface_was_up = interface_is_up(interface);

2738

errno = bring_up_interface(interface, delay);

2166

ret = bring_up_interface(interface, delay);

2739

2167

if(not interface_was_up){

2740

if(errno != 0){

2741

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

2742

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

2168

if(ret != 0){

2169

errno = ret;

2170

perror_plus("Failed to bring up interface");

2743

2171

} else {

2744

errno = argz_add(&interfaces_to_take_down,

2745

&interfaces_to_take_down_size,

2746

interface);

2747

if(errno != 0){

2748

perror_plus("argz_add");

2749

}

2172

ret_errno = argz_add(&interfaces_to_take_down,

2173

&interfaces_to_take_down_size,

2174

interface);

2750

2175

}

2751

2176

}

2752

2177

}

2178

free(interfaces);

2179

interfaces = NULL;

2180

interfaces_size = 0;

2753

2181

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

2754

2182

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

2755

2183

}

2756

2184

}

2757

2185

2758

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

2759

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

2760

if(debug){

2761

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

2762

mc.interfaces);

2763

}

2764

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

2765

}

2766

2767

2186

if(quit_now){

2768

2187

goto end;

2769

2188

}

2770

2189

2771

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

2190

ret = init_gnutls_global(pubkey, seckey);

2772

2191

if(ret == -1){

2773

2192

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

2774

2193

exitcode = EX_UNAVAILABLE;

2781

2200

goto end;

2782

2201

}

2783

2202

2784

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

2785

tempdir = mkdtemp(run_tempdir);

2786

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

2787

if(debug){

2788

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

2789

run_tempdir, old_tempdir);

2790

}

2791

tempdir = mkdtemp(old_tempdir);

2792

}

2793

if(tempdir == NULL){

2203

if(mkdtemp(tempdir) == NULL){

2794

2204

perror_plus("mkdtemp");

2795

2205

goto end;

2796

2206

}

2207

tempdir_created = true;

2797

2208

2798

2209

if(quit_now){

2799

2210

goto end;

2800

2211

}

2801

2212

2802

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

2213

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

2803

2214

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

2804

2215

exitcode = EX_UNAVAILABLE;

2805

2216

goto end;

2835

2246

exitcode = EX_USAGE;

2836

2247

goto end;

2837

2248

}

2838

2249

2839

2250

if(quit_now){

2840

2251

goto end;

2841

2252

}

2862

2273

}

2863

2274

2864

2275

while(not quit_now){

2865

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

2866

&mc);

2276

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

2867

2277

if(quit_now or ret == 0){

2868

2278

break;

2869

2279

}

2871

2281

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

2872

2282

(int)retry_interval);

2873

2283

}

2874

sleep((unsigned int)retry_interval);

2284

sleep((int)retry_interval);

2875

2285

}

2876

2286

2877

if(not quit_now){

2287

if (not quit_now){

2878

2288

exitcode = EXIT_SUCCESS;

2879

2289

}

2880

2290

2895

2305

config.publish_domain = 0;

2896

2306

2897

2307

/* Allocate a new server */

2898

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2899

&config, NULL, NULL, &ret);

2308

mc.server = avahi_server_new(avahi_simple_poll_get

2309

(mc.simple_poll), &config, NULL,

2310

NULL, &ret_errno);

2900

2311

2901

2312

/* Free the Avahi configuration data */

2902

2313

avahi_server_config_free(&config);

2905

2316

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

2906

2317

if(mc.server == NULL){

2907

2318

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

2908

avahi_strerror(ret));

2319

avahi_strerror(ret_errno));

2909

2320

exitcode = EX_UNAVAILABLE;

2910

2321

goto end;

2911

2322

}

2917

2328

/* Create the Avahi service browser */

2918

2329

sb = avahi_s_service_browser_new(mc.server, if_index,

2919

2330

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2920

NULL, 0, browse_callback,

2921

(void *)&mc);

2331

NULL, 0, browse_callback, NULL);

2922

2332

if(sb == NULL){

2923

2333

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

2924

2334

avahi_strerror(avahi_server_errno(mc.server)));

2935

2345

if(debug){

2936

2346

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

2937

2347

}

2938

2939

ret = avahi_loop_with_timeout(simple_poll,

2940

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

2348

2349

ret = avahi_loop_with_timeout(mc.simple_poll,

2350

(int)(retry_interval * 1000));

2941

2351

if(debug){

2942

2352

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

2943

2353

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

2950

2360

}

2951

2361

2952

2362

/* Cleanup things */

2953

free(mc.interfaces);

2954

2955

2363

if(sb != NULL)

2956

2364

avahi_s_service_browser_free(sb);

2957

2365

2958

2366

if(mc.server != NULL)

2959

2367

avahi_server_free(mc.server);

2960

2368

2961

if(simple_poll != NULL)

2962

avahi_simple_poll_free(simple_poll);

2369

if(mc.simple_poll != NULL)

2370

avahi_simple_poll_free(mc.simple_poll);

2963

2371

2964

2372

if(gnutls_initialized){

2965

2373

gnutls_certificate_free_credentials(mc.cred);

2374

gnutls_global_deinit();

2966

2375

gnutls_dh_params_deinit(mc.dh_params);

2967

2376

}

2968

2377

2976

2385

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

2977

2386

while(mc.current_server != NULL){

2978

2387

server *next = mc.current_server->next;

2979

#ifdef __GNUC__

2980

#pragma GCC diagnostic push

2981

#pragma GCC diagnostic ignored "-Wcast-qual"

2982

#endif

2983

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

2984

#ifdef __GNUC__

2985

#pragma GCC diagnostic pop

2986

#endif

2987

2388

free(mc.current_server);

2988

2389

mc.current_server = next;

2989

2390

}

2990

2391

}

2991

2392

2992

/* Re-raise privileges */

2393

/* Re-raise priviliges */

2993

2394

{

2994

ret = raise_privileges();

2995

if(ret != 0){

2996

errno = ret;

2997

perror_plus("Failed to raise privileges");

2998

} else {

2999

3000

/* Run network hooks */

3001

run_network_hooks("stop", interfaces_hooks != NULL ?

3002

interfaces_hooks : "", delay);

3003

3004

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

3005

{

3006

char *interface = NULL;

3007

while((interface=argz_next(interfaces_to_take_down,

3008

interfaces_to_take_down_size,

3009

interface))){

3010

ret = take_down_interface(interface);

3011

if(ret != 0){

3012

errno = ret;

3013

perror_plus("Failed to take down interface");

3014

}

3015

}

3016

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

3017

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

3018

" down\n");

3019

}

3020

}

3021

}

3022

3023

ret = lower_privileges_permanently();

3024

if(ret != 0){

3025

errno = ret;

3026

perror_plus("Failed to lower privileges permanently");

3027

}

2395

raise_privileges();

2396

2397

/* Run network hooks */

2398

run_network_hooks("stop", interfaces_hooks != NULL ?

2399

interfaces_hooks : "", delay);

2400

2401

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

2402

{

2403

char *interface = NULL;

2404

while((interface=argz_next(interfaces_to_take_down,

2405

interfaces_to_take_down_size,

2406

interface))){

2407

ret_errno = take_down_interface(interface);

2408

if(ret_errno != 0){

2409

errno = ret_errno;

2410

perror_plus("Failed to take down interface");

2411

}

2412

}

2413

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

2414

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

2415

" down\n");

2416

}

2417

}

2418

2419

lower_privileges_permanently();

3028

2420

}

3029

2421

3030

2422

free(interfaces_to_take_down);

3031

2423

free(interfaces_hooks);

3032

2424

3033

void clean_dir_at(int base, const char * const dirname,

3034

uintmax_t level){

2425

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

2426

if(tempdir_created){

3035

2427

struct dirent **direntries = NULL;

3036

int dret;

3037

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3038

O_RDONLY

3039

| O_NOFOLLOW

3040

| O_DIRECTORY

3041

| O_PATH));

3042

if(dir_fd == -1){

3043

perror_plus("open");

3044

}

3045

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

3046

notdotentries, alphasort);

3047

if(numentries >= 0){

2428

struct dirent *direntry = NULL;

2429

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

2430

alphasort);

2431

if (numentries > 0){

3048

2432

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

3049

if(debug){

3050

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3051

dirname, direntries[i]->d_name);

3052

}

3053

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3054

if(dret == -1){

3055

if(errno == EISDIR){

3056

dret = unlinkat(dir_fd, direntries[i]->d_name,

3057

AT_REMOVEDIR);

3058

}

3059

if((dret == -1) and (errno == ENOTEMPTY)

3060

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3061

== 0) and (level == 0)){

3062

/* Recurse only in this special case */

3063

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3064

dret = 0;

3065

}

3066

if(dret == -1){

3067

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3068

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

3069

}

3070

}

3071

free(direntries[i]);

3072

}

3073

3074

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

3075

free(direntries);

3076

if(numentries == -1){

3077

perror_plus("scandirat");

3078

}

3079

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3080

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

3081

perror_plus("rmdir");

3082

}

3083

} else {

3084

perror_plus("scandirat");

3085

}

3086

close(dir_fd);

3087

}

3088

3089

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

3090

if(tempdir != NULL){

3091

clean_dir_at(-1, tempdir, 0);

2433

direntry = direntries[i];

2434

char *fullname = NULL;

2435

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

2436

direntry->d_name);

2437

if(ret < 0){

2438

perror_plus("asprintf");

2439

continue;

2440

}

2441

ret = remove(fullname);

2442

if(ret == -1){

2443

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

2444

strerror(errno));

2445

}

2446

free(fullname);

2447

}

2448

}

2449

2450

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

2451

free(direntries);

2452

if (numentries == -1){

2453

perror_plus("scandir");

2454

}

2455

ret = rmdir(tempdir);

2456

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

2457

perror_plus("rmdir");

2458

}

3092

2459

}

3093

2460

3094

2461

if(quit_now){