/mandos/trunk : revision 876

9

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

10

*

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* Everything else is

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13

12

13

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*

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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40

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

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

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stdout, ferror(), remove() */

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stdout, ferror() */

44

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

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#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> /* memset(), strcmp(), strlen(),

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

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

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asprintf(), strncpy(), strsignal()

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*/

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52

#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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56

opendir(), DIR */

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57

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

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inet_pton(), connect(),

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getnameinfo() */

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

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62

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

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63

*/

62

64

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

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65

strtoimax() */

64

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

66

#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,

65

71

program_invocation_short_name */

66

72

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

67

73

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

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78

*/

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79

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

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

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

76

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

81

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

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unlinkat() */

83

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

77

84

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

78

85

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

79

86

argp_state, struct argp,

91

98

argz_delete(), argz_append(),

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99

argz_stringify(), argz_add(),

93

100

argz_count() */

101

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

102

EAI_SYSTEM, gai_strerror() */

94

103

95

104

#ifdef __linux__

96

105

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

138

147

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

139

148

char *connect_to = NULL;

140

149

const char *hookdir = HOOKDIR;

150

int hookdir_fd = -1;

141

151

uid_t uid = 65534;

142

152

gid_t gid = 65534;

143

153

154

164

155

165

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

156

166

typedef struct {

157

AvahiSimplePoll *simple_poll;

158

167

AvahiServer *server;

159

168

gnutls_certificate_credentials_t cred;

160

169

unsigned int dh_bits;

162

171

const char *priority;

163

172

gpgme_ctx_t ctx;

164

173

server *current_server;

174

char *interfaces;

175

size_t interfaces_size;

165

176

} mandos_context;

166

177

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 };

178

/* global so signal handler can reach it*/

179

AvahiSimplePoll *simple_poll;

172

180

173

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sig_atomic_t quit_now = 0;

174

182

int signal_received = 0;

182

190

perror(print_text);

183

191

}

184

192

185

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

193

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

186

194

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

187

195

va_list ap;

188

196

va_start (ap, format);

189

197

190

198

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

191

199

program_invocation_short_name));

192

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

200

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

193

201

}

194

202

195

203

/*

197

205

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

198

206

* "buffer_length" is how much is already used.

199

207

*/

208

__attribute__((nonnull, warn_unused_result))

200

209

size_t incbuffer(char **buffer, size_t buffer_length,

201

210

size_t buffer_capacity){

202

211

if(buffer_length + BUFFER_SIZE > buffer_capacity){

203

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

204

if(buffer == NULL){

212

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

213

if(new_buf == NULL){

214

int old_errno = errno;

215

free(*buffer);

216

errno = old_errno;

217

*buffer = NULL;

205

218

return 0;

206

219

}

220

*buffer = new_buf;

207

221

buffer_capacity += BUFFER_SIZE;

208

222

}

209

223

return buffer_capacity;

210

224

}

211

225

212

226

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

227

__attribute__((nonnull, warn_unused_result))

213

228

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

214

int af){

229

int af, server **current_server){

215

230

int ret;

216

231

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

217

232

if(new_server == NULL){

224

239

.af = af };

225

240

if(new_server->ip == NULL){

226

241

perror_plus("strdup");

242

free(new_server);

243

return false;

244

}

245

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

246

if(ret == -1){

247

perror_plus("clock_gettime");

248

#ifdef __GNUC__

249

#pragma GCC diagnostic push

250

#pragma GCC diagnostic ignored "-Wcast-qual"

251

#endif

252

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

253

#ifdef __GNUC__

254

#pragma GCC diagnostic pop

255

#endif

256

free(new_server);

227

257

return false;

228

258

}

229

259

/* Special case of first server */

230

if (mc.current_server == NULL){

260

if(*current_server == NULL){

231

261

new_server->next = new_server;

232

262

new_server->prev = new_server;

233

mc.current_server = new_server;

234

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

263

*current_server = new_server;

235

264

} else {

236

new_server->next = mc.current_server;

237

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

265

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

266

new_server->next = *current_server;

267

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

238

268

new_server->prev->next = 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

(*current_server)->prev = new_server;

245

270

}

246

271

return true;

247

272

}

249

274

/*

250

275

* Initialize GPGME.

251

276

*/

252

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

253

const char *tempdir){

277

__attribute__((nonnull, warn_unused_result))

278

static bool init_gpgme(const char * const seckey,

279

const char * const pubkey,

280

const char * const tempdir,

281

mandos_context *mc){

254

282

gpgme_error_t rc;

255

283

gpgme_engine_info_t engine_info;

256

284

257

258

285

/*

259

286

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

260

287

*/

261

bool import_key(const char *filename){

288

bool import_key(const char * const filename){

262

289

int ret;

263

290

int fd;

264

291

gpgme_data_t pgp_data;

276

303

return false;

277

304

}

278

305

279

rc = gpgme_op_import(mc.ctx, pgp_data);

306

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

280

307

if(rc != GPG_ERR_NO_ERROR){

281

308

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

282

309

gpgme_strsource(rc), gpgme_strerror(rc));

283

310

return false;

284

311

}

285

312

286

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

313

ret = close(fd);

287

314

if(ret == -1){

288

315

perror_plus("close");

289

316

}

326

353

}

327

354

328

355

/* Create new GPGME "context" */

329

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

356

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

330

357

if(rc != GPG_ERR_NO_ERROR){

331

358

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

332

359

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

345

372

* Decrypt OpenPGP data.

346

373

* Returns -1 on error

347

374

*/

375

__attribute__((nonnull, warn_unused_result))

348

376

static ssize_t pgp_packet_decrypt(const char *cryptotext,

349

377

size_t crypto_size,

350

char **plaintext){

378

char **plaintext,

379

mandos_context *mc){

351

380

gpgme_data_t dh_crypto, dh_plain;

352

381

gpgme_error_t rc;

353

382

ssize_t ret;

379

408

380

409

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

381

410

data buffer */

382

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

411

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

383

412

if(rc != GPG_ERR_NO_ERROR){

384

413

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

385

414

gpgme_strsource(rc), gpgme_strerror(rc));

386

415

plaintext_length = -1;

387

416

if(debug){

388

417

gpgme_decrypt_result_t result;

389

result = gpgme_op_decrypt_result(mc.ctx);

418

result = gpgme_op_decrypt_result(mc->ctx);

390

419

if(result == NULL){

391

420

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

392

421

} else {

469

498

return plaintext_length;

470

499

}

471

500

472

static const char * safer_gnutls_strerror(int value){

501

__attribute__((warn_unused_result, const))

502

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

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

508

__attribute__((warn_unused_result))

509

static const char *safer_gnutls_strerror(int value){

473

510

const char *ret = gnutls_strerror(value);

474

if(ret == NULL)

475

ret = "(unknown)";

476

return ret;

511

return safe_string(ret);

477

512

}

478

513

479

514

/* GnuTLS log function callback */

515

__attribute__((nonnull))

480

516

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

481

517

const char* string){

482

518

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

483

519

}

484

520

521

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

485

522

static int init_gnutls_global(const char *pubkeyfilename,

486

const char *seckeyfilename){

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

mandos_context *mc){

487

526

int ret;

527

unsigned int uret;

488

528

489

529

if(debug){

490

530

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

491

531

}

492

532

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

500

533

if(debug){

501

534

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

502

535

* - GnuTLS manual

506

539

}

507

540

508

541

/* OpenPGP credentials */

509

ret = gnutls_certificate_allocate_credentials(&mc.cred);

542

ret = gnutls_certificate_allocate_credentials(&mc->cred);

510

543

if(ret != GNUTLS_E_SUCCESS){

511

544

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

512

545

safer_gnutls_strerror(ret));

513

gnutls_global_deinit();

514

546

return -1;

515

547

}

516

548

522

554

}

523

555

524

556

ret = gnutls_certificate_set_openpgp_key_file

525

(mc.cred, pubkeyfilename, seckeyfilename,

557

(mc->cred, pubkeyfilename, seckeyfilename,

526

558

GNUTLS_OPENPGP_FMT_BASE64);

527

559

if(ret != GNUTLS_E_SUCCESS){

528

560

fprintf_plus(stderr,

534

566

}

535

567

536

568

/* GnuTLS server initialization */

537

ret = gnutls_dh_params_init(&mc.dh_params);

569

ret = gnutls_dh_params_init(&mc->dh_params);

538

570

if(ret != GNUTLS_E_SUCCESS){

539

571

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

540

572

" initialization: %s\n",

541

573

safer_gnutls_strerror(ret));

542

574

goto globalfail;

543

575

}

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);

576

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

577

if(dhparamsfilename != NULL){

578

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

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

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

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

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

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

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

625

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

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

} while(false);

630

}

631

if(dhparamsfilename == NULL){

632

if(mc->dh_bits == 0){

633

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

634

/* Try to read the private key file */

635

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

636

do {

637

int secfile = open(seckeyfilename, O_RDONLY);

638

if(secfile == -1){

639

perror_plus("open");

640

break;

641

}

642

size_t buffer_capacity = 0;

643

while(true){

644

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

645

(size_t)buffer.size,

646

(size_t)buffer_capacity);

647

if(buffer_capacity == 0){

648

perror_plus("incbuffer");

649

free(buffer.data);

650

buffer.data = NULL;

651

break;

652

}

653

ssize_t bytes_read = read(secfile,

654

buffer.data + buffer.size,

655

BUFFER_SIZE);

656

/* EOF */

657

if(bytes_read == 0){

658

break;

659

}

660

/* check bytes_read for failure */

661

if(bytes_read < 0){

662

perror_plus("read");

663

free(buffer.data);

664

buffer.data = NULL;

665

break;

666

}

667

buffer.size += (unsigned int)bytes_read;

668

}

669

close(secfile);

670

} while(false);

671

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

672

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

673

if(buffer.data != NULL){

674

{

675

gnutls_openpgp_privkey_t privkey = NULL;

676

ret = gnutls_openpgp_privkey_init(&privkey);

677

if(ret != GNUTLS_E_SUCCESS){

678

fprintf_plus(stderr, "Error initializing OpenPGP key"

679

" structure: %s",

680

safer_gnutls_strerror(ret));

681

free(buffer.data);

682

buffer.data = NULL;

683

} else {

684

ret = gnutls_openpgp_privkey_import

685

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

686

if(ret != GNUTLS_E_SUCCESS){

687

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

688

safer_gnutls_strerror(ret));

689

privkey = NULL;

690

}

691

free(buffer.data);

692

buffer.data = NULL;

693

if(privkey != NULL){

694

/* Use private key to suggest an appropriate

695

sec_param */

696

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

697

gnutls_openpgp_privkey_deinit(privkey);

698

if(debug){

699

fprintf_plus(stderr, "This OpenPGP key implies using"

700

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

701

safe_string(gnutls_sec_param_get_name

702

(sec_param)));

703

}

704

}

705

}

706

}

707

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

708

/* Err on the side of caution */

709

sec_param = GNUTLS_SEC_PARAM_ULTRA;

710

if(debug){

711

fprintf_plus(stderr, "Falling back to security parameter"

712

" \"%s\"\n",

713

safe_string(gnutls_sec_param_get_name

714

(sec_param)));

715

}

716

}

717

}

718

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

719

if(uret != 0){

720

mc->dh_bits = uret;

721

if(debug){

722

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

723

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

724

safe_string(gnutls_sec_param_get_name

725

(sec_param)),

726

mc->dh_bits);

727

}

728

} else {

729

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

730

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

731

safe_string(gnutls_sec_param_get_name

732

(sec_param)),

733

safer_gnutls_strerror(ret));

734

goto globalfail;

735

}

736

} else if(debug){

737

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

738

mc->dh_bits);

739

}

740

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

741

if(ret != GNUTLS_E_SUCCESS){

742

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

743

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

744

safer_gnutls_strerror(ret));

745

goto globalfail;

746

}

747

}

748

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

552

749

553

750

return 0;

554

751

555

752

globalfail:

556

753

557

gnutls_certificate_free_credentials(mc.cred);

558

gnutls_global_deinit();

559

gnutls_dh_params_deinit(mc.dh_params);

754

gnutls_certificate_free_credentials(mc->cred);

755

gnutls_dh_params_deinit(mc->dh_params);

560

756

return -1;

561

757

}

562

758

563

static int init_gnutls_session(gnutls_session_t *session){

759

__attribute__((nonnull, warn_unused_result))

760

static int init_gnutls_session(gnutls_session_t *session,

761

mandos_context *mc){

564

762

int ret;

565

763

/* GnuTLS session creation */

566

764

do {

578

776

{

579

777

const char *err;

580

778

do {

581

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

779

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

582

780

if(quit_now){

583

781

gnutls_deinit(*session);

584

782

return -1;

595

793

596

794

do {

597

795

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

598

mc.cred);

796

mc->cred);

599

797

if(quit_now){

600

798

gnutls_deinit(*session);

601

799

return -1;

611

809

/* ignore client certificate if any. */

612

810

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

811

614

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

615

616

812

return 0;

617

813

}

618

814

620

816

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

621

817

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

622

818

819

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

820

__attribute__((warn_unused_result))

821

int raise_privileges(void){

822

int old_errno = errno;

823

int ret = 0;

824

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

825

ret = errno;

826

}

827

errno = old_errno;

828

return ret;

829

}

830

831

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

832

__attribute__((warn_unused_result))

833

int raise_privileges_permanently(void){

834

int old_errno = errno;

835

int ret = raise_privileges();

836

if(ret != 0){

837

errno = old_errno;

838

return ret;

839

}

840

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

841

ret = errno;

842

}

843

errno = old_errno;

844

return ret;

845

}

846

847

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

848

__attribute__((warn_unused_result))

849

int lower_privileges(void){

850

int old_errno = errno;

851

int ret = 0;

852

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

853

ret = errno;

854

}

855

errno = old_errno;

856

return ret;

857

}

858

859

/* Lower privileges permanently */

860

__attribute__((warn_unused_result))

861

int lower_privileges_permanently(void){

862

int old_errno = errno;

863

int ret = 0;

864

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

865

ret = errno;

866

}

867

errno = old_errno;

868

return ret;

869

}

870

871

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

872

__attribute__((nonnull, warn_unused_result))

873

static bool add_delete_local_route(const bool add,

874

const char *address,

875

AvahiIfIndex if_index){

876

int ret;

877

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

878

char add_arg[] = "add";

879

char delete_arg[] = "delete";

880

char debug_flag[] = "--debug";

881

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

882

if(pluginhelperdir == NULL){

883

if(debug){

884

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

885

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

886

}

887

return false;

888

}

889

890

char interface[IF_NAMESIZE];

891

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

892

perror_plus("if_indextoname");

893

return false;

894

}

895

896

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

897

if(devnull == -1){

898

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

899

return false;

900

}

901

pid_t pid = fork();

902

if(pid == 0){

903

/* Child */

904

/* Raise privileges */

905

errno = raise_privileges_permanently();

906

if(errno != 0){

907

perror_plus("Failed to raise privileges");

908

/* _exit(EX_NOPERM); */

909

} else {

910

/* Set group */

911

errno = 0;

912

ret = setgid(0);

913

if(ret == -1){

914

perror_plus("setgid");

915

_exit(EX_NOPERM);

916

}

917

/* Reset supplementary groups */

918

errno = 0;

919

ret = setgroups(0, NULL);

920

if(ret == -1){

921

perror_plus("setgroups");

922

_exit(EX_NOPERM);

923

}

924

}

925

ret = dup2(devnull, STDIN_FILENO);

926

if(ret == -1){

927

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

928

_exit(EX_OSERR);

929

}

930

ret = close(devnull);

931

if(ret == -1){

932

perror_plus("close");

933

_exit(EX_OSERR);

934

}

935

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

936

if(ret == -1){

937

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

938

_exit(EX_OSERR);

939

}

940

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

941

O_RDONLY

942

| O_DIRECTORY

943

| O_PATH

944

| O_CLOEXEC));

945

if(helperdir_fd == -1){

946

perror_plus("open");

947

_exit(EX_UNAVAILABLE);

948

}

949

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

950

helper, O_RDONLY));

951

if(helper_fd == -1){

952

perror_plus("openat");

953

close(helperdir_fd);

954

_exit(EX_UNAVAILABLE);

955

}

956

close(helperdir_fd);

957

#ifdef __GNUC__

958

#pragma GCC diagnostic push

959

#pragma GCC diagnostic ignored "-Wcast-qual"

960

#endif

961

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

962

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

963

interface, debug ? debug_flag : NULL, NULL },

964

environ) == -1){

965

#ifdef __GNUC__

966

#pragma GCC diagnostic pop

967

#endif

968

perror_plus("fexecve");

969

_exit(EXIT_FAILURE);

970

}

971

}

972

if(pid == -1){

973

perror_plus("fork");

974

return false;

975

}

976

int status;

977

pid_t pret = -1;

978

errno = 0;

979

do {

980

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

981

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

982

int errno_raising = 0;

983

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

984

errno_raising = errno;

985

perror_plus("Failed to raise privileges in order to"

986

" kill helper program");

987

}

988

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

989

perror_plus("kill");

990

}

991

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

992

perror_plus("Failed to lower privileges after killing"

993

" helper program");

994

}

995

return false;

996

}

997

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

998

if(pret == -1){

999

perror_plus("waitpid");

1000

return false;

1001

}

1002

if(WIFEXITED(status)){

1003

if(WEXITSTATUS(status) != 0){

1004

fprintf_plus(stderr, "Error: iprouteadddel exited"

1005

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

1006

return false;

1007

}

1008

return true;

1009

}

1010

if(WIFSIGNALED(status)){

1011

fprintf_plus(stderr, "Error: iprouteadddel died by"

1012

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

1013

return false;

1014

}

1015

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

1016

return false;

1017

}

1018

1019

__attribute__((nonnull, warn_unused_result))

1020

static bool add_local_route(const char *address,

1021

AvahiIfIndex if_index){

1022

if(debug){

1023

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

1024

}

1025

return add_delete_local_route(true, address, if_index);

1026

}

1027

1028

__attribute__((nonnull, warn_unused_result))

1029

static bool delete_local_route(const char *address,

1030

AvahiIfIndex if_index){

1031

if(debug){

1032

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

1033

}

1034

return add_delete_local_route(false, address, if_index);

1035

}

1036

623

1037

/* Called when a Mandos server is found */

1038

__attribute__((nonnull, warn_unused_result))

624

1039

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

625

1040

AvahiIfIndex if_index,

626

int af){

1041

int af, mandos_context *mc){

627

1042

int ret, tcp_sd = -1;

628

1043

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1044

struct sockaddr_storage to;

633

1045

char *buffer = NULL;

634

1046

char *decrypted_buffer = NULL;

635

1047

size_t buffer_length = 0;

638

1050

int retval = -1;

639

1051

gnutls_session_t session;

640

1052

int pf; /* Protocol family */

1053

bool route_added = false;

641

1054

642

1055

errno = 0;

643

1056

659

1072

return -1;

660

1073

}

661

1074

662

ret = init_gnutls_session(&session);

1075

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

1076

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

1077

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

1078

bool match = false;

1079

{

1080

char *interface = NULL;

1081

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

1082

interface))){

1083

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

1084

match = true;

1085

break;

1086

}

1087

}

1088

}

1089

if(not match){

1090

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

1091

connect to the server */

1092

if(debug){

1093

char interface[IF_NAMESIZE];

1094

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

1095

perror_plus("if_indextoname");

1096

} else {

1097

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

1098

" \"%s\"\n",

1099

if_indextoname((unsigned int)if_index,

1100

interface));

1101

}

1102

}

1103

return -1;

1104

}

1105

}

1106

1107

ret = init_gnutls_session(&session, mc);

663

1108

if(ret != 0){

664

1109

return -1;

665

1110

}

669

1114

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

670

1115

}

671

1116

672

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

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

673

1118

if(tcp_sd < 0){

674

1119

int e = errno;

675

1120

perror_plus("socket");

682

1127

goto mandos_end;

683

1128

}

684

1129

685

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

686

1130

if(af == AF_INET6){

687

to.in6.sin6_family = (sa_family_t)af;

688

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

1131

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

1132

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

1133

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

689

1134

} else { /* IPv4 */

690

to.in.sin_family = (sa_family_t)af;

691

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

1135

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

1136

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

1137

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

692

1138

}

693

1139

if(ret < 0 ){

694

1140

int e = errno;

703

1149

goto mandos_end;

704

1150

}

705

1151

if(af == AF_INET6){

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*/

1152

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

1153

if(IN6_IS_ADDR_LINKLOCAL

1154

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

710

1155

if(if_index == AVAHI_IF_UNSPEC){

711

1156

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

712

1157

" incomplete without a network interface\n");

714

1159

goto mandos_end;

715

1160

}

716

1161

/* Set the network interface number as scope */

717

to.in6.sin6_scope_id = (uint32_t)if_index;

1162

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

718

1163

}

719

1164

} else {

720

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

721

-Wconversion and

722

-Wunreachable-code */

1165

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

723

1166

}

724

1167

725

1168

if(quit_now){

742

1185

}

743

1186

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

744

1187

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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;

1188

if(af == AF_INET6){

1189

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

1190

sizeof(struct sockaddr_in6),

1191

addrstr, sizeof(addrstr), NULL, 0,

1192

NI_NUMERICHOST);

1193

} else {

1194

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

1195

sizeof(struct sockaddr_in),

1196

addrstr, sizeof(addrstr), NULL, 0,

1197

NI_NUMERICHOST);

1198

}

1199

if(ret == EAI_SYSTEM){

1200

perror_plus("getnameinfo");

1201

} else if(ret != 0) {

1202

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

1203

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

1204

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

1205

}

1206

}

1207

1208

if(quit_now){

1209

errno = EINTR;

1210

goto mandos_end;

1211

}

1212

1213

while(true){

1214

if(af == AF_INET6){

1215

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

1216

sizeof(struct sockaddr_in6));

1217

} else {

1218

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

1219

sizeof(struct sockaddr_in));

1220

}

1221

if(ret < 0){

1222

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

1223

and if_index != AVAHI_IF_UNSPEC

1224

and connect_to == NULL

1225

and not route_added and

1226

((af == AF_INET6 and not

1227

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1228

&to)->sin6_addr)))

1229

or (af == AF_INET and

1230

/* Not a a IPv4LL address */

1231

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

1232

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

1233

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

1234

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

1235

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

1236

connect to a Mandos server announced by Avahi on a server

1237

host with a global address. Work around this by retrying

1238

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

1239

1240

Avahi bug reference:

1241

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

1242

https://bugs.debian.org/587961

1243

*/

1244

if(debug){

1245

fprintf_plus(stderr, "Mandos server unreachable, trying"

1246

" direct route\n");

1247

}

1248

int e = errno;

1249

route_added = add_local_route(ip, if_index);

1250

if(route_added){

1251

continue;

1252

}

1253

errno = e;

1254

}

1255

if(errno != ECONNREFUSED or debug){

1256

int e = errno;

1257

perror_plus("connect");

1258

errno = e;

1259

}

1260

goto mandos_end;

1261

}

1262

1263

if(quit_now){

1264

errno = EINTR;

1265

goto mandos_end;

1266

}

1267

break;

784

1268

}

785

1269

786

1270

const char *out = mandos_protocol_version;

937

1421

if(buffer_length > 0){

938

1422

ssize_t decrypted_buffer_size;

939

1423

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

940

&decrypted_buffer);

1424

&decrypted_buffer, mc);

941

1425

if(decrypted_buffer_size >= 0){

942

1426

1427

clearerr(stdout);

943

1428

written = 0;

944

1429

while(written < (size_t) decrypted_buffer_size){

945

1430

if(quit_now){

961

1446

}

962

1447

written += (size_t)ret;

963

1448

}

1449

ret = fflush(stdout);

1450

if(ret != 0){

1451

int e = errno;

1452

if(debug){

1453

fprintf_plus(stderr, "Error writing encrypted data: %s\n",

1454

strerror(errno));

1455

}

1456

errno = e;

1457

goto mandos_end;

1458

}

964

1459

retval = 0;

965

1460

}

966

1461

}

969

1464

970

1465

mandos_end:

971

1466

{

1467

if(route_added){

1468

if(not delete_local_route(ip, if_index)){

1469

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

1470

" interface %d", ip, if_index);

1471

}

1472

}

972

1473

int e = errno;

973

1474

free(decrypted_buffer);

974

1475

free(buffer);

975

1476

if(tcp_sd >= 0){

976

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

1477

ret = close(tcp_sd);

977

1478

}

978

1479

if(ret == -1){

979

1480

if(e == 0){

991

1492

return retval;

992

1493

}

993

1494

1495

__attribute__((nonnull))

994

1496

static void resolve_callback(AvahiSServiceResolver *r,

995

1497

AvahiIfIndex interface,

996

1498

AvahiProtocol proto,

1004

1506

AVAHI_GCC_UNUSED AvahiStringList *txt,

1005

1507

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1006

1508

flags,

1007

AVAHI_GCC_UNUSED void* userdata){

1509

void *mc){

1008

1510

if(r == NULL){

1009

1511

return;

1010

1512

}

1013

1515

timed out */

1014

1516

1015

1517

if(quit_now){

1518

avahi_s_service_resolver_free(r);

1016

1519

return;

1017

1520

}

1018

1521

1022

1525

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

1023

1526

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

1024

1527

domain,

1025

avahi_strerror(avahi_server_errno(mc.server)));

1528

avahi_strerror(avahi_server_errno

1529

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

1026

1530

break;

1027

1531

1028

1532

case AVAHI_RESOLVER_FOUND:

1036

1540

}

1037

1541

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

1038

1542

interface,

1039

avahi_proto_to_af(proto));

1543

avahi_proto_to_af(proto),

1544

mc);

1040

1545

if(ret == 0){

1041

avahi_simple_poll_quit(mc.simple_poll);

1546

avahi_simple_poll_quit(simple_poll);

1042

1547

} else {

1043

1548

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

1044

avahi_proto_to_af(proto))){

1549

avahi_proto_to_af(proto),

1550

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

1045

1551

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

1046

1552

" list\n", name);

1047

1553

}

1060

1566

const char *domain,

1061

1567

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1062

1568

flags,

1063

AVAHI_GCC_UNUSED void* userdata){

1569

void *mc){

1064

1570

if(b == NULL){

1065

1571

return;

1066

1572

}

1077

1583

case AVAHI_BROWSER_FAILURE:

1078

1584

1079

1585

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1586

avahi_strerror(avahi_server_errno

1587

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

1588

avahi_simple_poll_quit(simple_poll);

1082

1589

return;

1083

1590

1084

1591

case AVAHI_BROWSER_NEW:

1087

1594

the callback function is called the Avahi server will free the

1088

1595

resolver for us. */

1089

1596

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1597

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

1598

interface, protocol, name, type,

1599

domain, protocol, 0,

1600

resolve_callback, mc) == NULL)

1093

1601

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

1094

1602

" %s\n", name,

1095

avahi_strerror(avahi_server_errno(mc.server)));

1603

avahi_strerror(avahi_server_errno

1604

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

1096

1605

break;

1097

1606

1098

1607

case AVAHI_BROWSER_REMOVE:

1117

1626

signal_received = sig;

1118

1627

int old_errno = errno;

1119

1628

/* set main loop to exit */

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1629

if(simple_poll != NULL){

1630

avahi_simple_poll_quit(simple_poll);

1122

1631

}

1123

1632

errno = old_errno;

1124

1633

}

1125

1634

1635

__attribute__((nonnull, warn_unused_result))

1126

1636

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

1127

1637

int ret;

1128

error_t ret_errno;

1638

int old_errno;

1129

1639

1130

1640

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

1131

1641

if(s < 0){

1132

ret_errno = errno;

1642

old_errno = errno;

1133

1643

perror_plus("socket");

1134

errno = ret_errno;

1644

errno = old_errno;

1135

1645

return false;

1136

1646

}

1137

strcpy(ifr->ifr_name, ifname);

1647

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

1648

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

1138

1649

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1139

1650

if(ret == -1){

1140

1651

if(debug){

1141

ret_errno = errno;

1652

old_errno = errno;

1142

1653

perror_plus("ioctl SIOCGIFFLAGS");

1143

errno = ret_errno;

1654

errno = old_errno;

1144

1655

}

1145

1656

return false;

1146

1657

}

1147

1658

return true;

1148

1659

}

1149

1660

1661

__attribute__((nonnull, warn_unused_result))

1150

1662

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

1151

1663

1152

1664

/* Reject the loopback device */

1194

1706

* corresponds to an acceptable network device.

1195

1707

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

1196

1708

*/

1709

__attribute__((nonnull, warn_unused_result))

1197

1710

int good_interface(const struct dirent *if_entry){

1198

1711

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

1199

1712

return 0;

1217

1730

/*

1218

1731

* This function determines if a network interface is up.

1219

1732

*/

1733

__attribute__((nonnull, warn_unused_result))

1220

1734

bool interface_is_up(const char *interface){

1221

1735

struct ifreq ifr;

1222

1736

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

1233

1747

/*

1234

1748

* This function determines if a network interface is running

1235

1749

*/

1750

__attribute__((nonnull, warn_unused_result))

1236

1751

bool interface_is_running(const char *interface){

1237

1752

struct ifreq ifr;

1238

1753

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

1246

1761

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

1247

1762

}

1248

1763

1764

__attribute__((nonnull, pure, warn_unused_result))

1249

1765

int notdotentries(const struct dirent *direntry){

1250

1766

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

1251

1767

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

1258

1774

}

1259

1775

1260

1776

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

1777

__attribute__((nonnull, warn_unused_result))

1261

1778

int runnable_hook(const struct dirent *direntry){

1262

1779

int ret;

1263

1780

size_t sret;

1271

1788

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

1272

1789

"abcdefghijklmnopqrstuvwxyz"

1273

1790

"0123456789"

1274

"_-");

1791

"_.-");

1275

1792

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

1276

1793

/* Contains non-allowed characters */

1277

1794

if(debug){

1281

1798

return 0;

1282

1799

}

1283

1800

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);

1801

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

1292

1802

if(ret == -1){

1293

1803

if(debug){

1294

1804

perror_plus("Could not stat hook");

1318

1828

return 1;

1319

1829

}

1320

1830

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1831

__attribute__((nonnull, warn_unused_result))

1832

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1833

mandos_context *mc){

1322

1834

int ret;

1323

1835

struct timespec now;

1324

1836

struct timespec waited_time;

1325

1837

intmax_t block_time;

1326

1838

1327

1839

while(true){

1328

if(mc.current_server == NULL){

1329

if (debug){

1840

if(mc->current_server == NULL){

1841

if(debug){

1330

1842

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

1331

1843

" No timeout!\n");

1332

1844

}

1333

1845

ret = avahi_simple_poll_iterate(s, -1);

1334

1846

} else {

1335

if (debug){

1847

if(debug){

1336

1848

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

1337

1849

" it, or wait\n");

1338

1850

}

1345

1857

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

1346

1858

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

1347

1859

waited_time.tv_sec = (now.tv_sec

1348

- mc.current_server->last_seen.tv_sec);

1860

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

1349

1861

waited_time.tv_nsec = (now.tv_nsec

1350

- mc.current_server->last_seen.tv_nsec);

1862

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

1351

1863

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

1352

1864

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

1353

1865

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

1355

1867

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

1356

1868

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

1357

1869

1358

if (debug){

1870

if(debug){

1359

1871

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

1360

1872

block_time);

1361

1873

}

1362

1874

1363

1875

if(block_time <= 0){

1364

ret = start_mandos_communication(mc.current_server->ip,

1365

mc.current_server->port,

1366

mc.current_server->if_index,

1367

mc.current_server->af);

1876

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

1877

mc->current_server->port,

1878

mc->current_server->if_index,

1879

mc->current_server->af, mc);

1368

1880

if(ret == 0){

1369

avahi_simple_poll_quit(mc.simple_poll);

1881

avahi_simple_poll_quit(s);

1370

1882

return 0;

1371

1883

}

1372

1884

ret = clock_gettime(CLOCK_MONOTONIC,

1373

&mc.current_server->last_seen);

1885

&mc->current_server->last_seen);

1374

1886

if(ret == -1){

1375

1887

perror_plus("clock_gettime");

1376

1888

return -1;

1377

1889

}

1378

mc.current_server = mc.current_server->next;

1890

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

1379

1891

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

1380

1892

servers, but don't block */

1381

1893

}

1383

1895

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

1384

1896

}

1385

1897

if(ret != 0){

1386

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

1898

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

1387

1899

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

1388

1900

}

1389

1901

}

1390

1902

}

1391

1903

}

1392

1904

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,

1905

__attribute__((nonnull))

1906

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

1446

1907

const float delay){

1447

struct dirent **direntries;

1908

struct dirent **direntries = NULL;

1909

if(hookdir_fd == -1){

1910

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1911

| O_CLOEXEC);

1912

if(hookdir_fd == -1){

1913

if(errno == ENOENT){

1914

if(debug){

1915

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

1916

" found\n", hookdir);

1917

}

1918

} else {

1919

perror_plus("open");

1920

}

1921

return;

1922

}

1923

}

1924

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

1925

runnable_hook, alphasort);

1926

if(numhooks == -1){

1927

perror_plus("scandir");

1928

return;

1929

}

1448

1930

struct dirent *direntry;

1449

1931

int ret;

1450

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

1451

alphasort);

1452

if(numhooks == -1){

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");

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);

1460

1942

}

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){

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){

1468

1989

perror_plus("asprintf");

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

}

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1527

1994

free(delaystring);

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

}

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(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 = 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;

1539

2063

} else {

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;

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(close(hookdir_fd) == -1){

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

1576

2083

}

1577

2084

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;

2085

__attribute__((nonnull, warn_unused_result))

2086

int bring_up_interface(const char *const interface,

2087

const float delay){

2088

int old_errno = errno;

2089

int ret;

1584

2090

struct ifreq network;

1585

2091

unsigned int if_index = if_nametoindex(interface);

1586

2092

if(if_index == 0){

1595

2101

}

1596

2102

1597

2103

if(not interface_is_up(interface)){

1598

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

2104

int ret_errno = 0;

2105

int ioctl_errno = 0;

2106

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

1599

2107

ret_errno = errno;

1600

2108

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

1601

2109

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

2110

errno = old_errno;

1602

2111

return ret_errno;

1603

2112

}

1604

network.ifr_flags |= IFF_UP;

2113

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

1605

2114

1606

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1607

if(sd < 0){

2115

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

2116

if(sd == -1){

1608

2117

ret_errno = errno;

1609

2118

perror_plus("socket");

1610

2119

errno = old_errno;

1611

2120

return ret_errno;

1612

2121

}

1613

2122

1614

2123

if(quit_now){

1615

close(sd);

2124

ret = close(sd);

2125

if(ret == -1){

2126

perror_plus("close");

2127

}

1616

2128

errno = old_errno;

1617

2129

return EINTR;

1618

2130

}

1622

2134

interface);

1623

2135

}

1624

2136

1625

/* Raise priviliges */

1626

raise_privileges();

2137

/* Raise privileges */

2138

ret_errno = raise_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to raise privileges");

2142

}

1627

2143

1628

2144

#ifdef __linux__

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");

2145

int ret_linux;

2146

bool restore_loglevel = false;

2147

if(ret_errno == 0){

2148

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2149

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

2150

ret_linux = klogctl(8, NULL, 5);

2151

if(ret_linux == -1){

2152

perror_plus("klogctl");

2153

} else {

2154

restore_loglevel = true;

2155

}

1636

2156

}

1637

2157

#endif /* __linux__ */

1638

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

1639

ret_errno = errno;

2158

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

2159

ioctl_errno = errno;

1640

2160

#ifdef __linux__

1641

2161

if(restore_loglevel){

1642

2162

ret_linux = klogctl(7, NULL, 0);

1646

2166

}

1647

2167

#endif /* __linux__ */

1648

2168

1649

/* Lower privileges */

1650

lower_privileges();

2169

/* If raise_privileges() succeeded above */

2170

if(ret_errno == 0){

2171

/* Lower privileges */

2172

ret_errno = lower_privileges();

2173

if(ret_errno != 0){

2174

errno = ret_errno;

2175

perror_plus("Failed to lower privileges");

2176

}

2177

}

1651

2178

1652

2179

/* Close the socket */

1653

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

2180

ret = close(sd);

1654

2181

if(ret == -1){

1655

2182

perror_plus("close");

1656

2183

}

1657

2184

1658

2185

if(ret_setflags == -1){

1659

errno = ret_errno;

2186

errno = ioctl_errno;

1660

2187

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1661

2188

errno = old_errno;

1662

return ret_errno;

2189

return ioctl_errno;

1663

2190

}

1664

2191

} else if(debug){

1665

2192

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

1683

2210

return 0;

1684

2211

}

1685

2212

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;

2213

__attribute__((nonnull, warn_unused_result))

2214

int take_down_interface(const char *const interface){

2215

int old_errno = errno;

1691

2216

struct ifreq network;

1692

2217

unsigned int if_index = if_nametoindex(interface);

1693

2218

if(if_index == 0){

1696

2221

return ENXIO;

1697

2222

}

1698

2223

if(interface_is_up(interface)){

2224

int ret_errno = 0;

2225

int ioctl_errno = 0;

1699

2226

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

1700

2227

ret_errno = errno;

1701

2228

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

1702

2229

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

2230

errno = old_errno;

1703

2231

return ret_errno;

1704

2232

}

1705

2233

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

1706

2234

1707

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1708

if(sd < 0){

2235

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

2236

if(sd == -1){

1709

2237

ret_errno = errno;

1710

2238

perror_plus("socket");

1711

2239

errno = old_errno;

1717

2245

interface);

1718

2246

}

1719

2247

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();

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

2254

2255

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

2256

ioctl_errno = errno;

2257

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

1728

2267

1729

2268

/* Close the socket */

1730

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

2269

int ret = close(sd);

1731

2270

if(ret == -1){

1732

2271

perror_plus("close");

1733

2272

}

1734

2273

1735

2274

if(ret_setflags == -1){

1736

errno = ret_errno;

2275

errno = ioctl_errno;

1737

2276

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1738

2277

errno = old_errno;

1739

return ret_errno;

2278

return ioctl_errno;

1740

2279

}

1741

2280

} else if(debug){

1742

2281

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

1748

2287

}

1749

2288

1750

2289

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

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

1751

2295

AvahiSServiceBrowser *sb = NULL;

1752

2296

error_t ret_errno;

1753

2297

int ret;

1754

2298

intmax_t tmpmax;

1755

2299

char *tmp;

1756

2300

int exitcode = EXIT_SUCCESS;

1757

char *interfaces = NULL;

1758

size_t interfaces_size = 0;

1759

2301

char *interfaces_to_take_down = NULL;

1760

2302

size_t interfaces_to_take_down_size = 0;

1761

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

1762

bool tempdir_created = false;

2303

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

2304

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

2305

char *tempdir = NULL;

1763

2306

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1764

2307

const char *seckey = PATHDIR "/" SECKEY;

1765

2308

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

1766

2310

char *interfaces_hooks = NULL;

1767

size_t interfaces_hooks_size = 0;

1768

2311

1769

2312

bool gnutls_initialized = false;

1770

2313

bool gpgme_initialized = false;

1822

2365

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

1823

2366

" Diffie-Hellman key exchange",

1824

2367

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

1825

2373

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

1826

2374

.arg = "STRING",

1827

2375

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

1861

2409

connect_to = arg;

1862

2410

break;

1863

2411

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

1864

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

1865

(int)',');

2412

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

2413

arg, (int)',');

1866

2414

if(ret_errno != 0){

1867

2415

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

1868

2416

}

1882

2430

}

1883

2431

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

1884

2432

break;

2433

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

2434

dh_params_file = arg;

2435

break;

1885

2436

case 130: /* --priority */

1886

2437

mc.priority = arg;

1887

2438

break;

1927

2478

.args_doc = "",

1928

2479

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

1929

2480

" passwords from a Mandos server" };

1930

ret = argp_parse(&argp, argc, argv,

1931

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1932

switch(ret){

2481

ret_errno = argp_parse(&argp, argc, argv,

2482

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2483

switch(ret_errno){

1933

2484

case 0:

1934

2485

break;

1935

2486

case ENOMEM:

1936

2487

default:

1937

errno = ret;

2488

errno = ret_errno;

1938

2489

perror_plus("argp_parse");

1939

2490

exitcode = EX_OSERR;

1940

2491

goto end;

1943

2494

goto end;

1944

2495

}

1945

2496

}

1946

2497

1947

2498

{

1948

2499

/* Work around Debian bug #633582:

1949

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

2500

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

1950

2501

1951

/* Re-raise priviliges */

1952

if(raise_privileges() == 0){

2502

/* Re-raise privileges */

2503

ret = raise_privileges();

2504

if(ret != 0){

2505

errno = ret;

2506

perror_plus("Failed to raise privileges");

2507

} else {

1953

2508

struct stat st;

1954

2509

1955

2510

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

1969

2524

}

1970

2525

}

1971

2526

}

1972

TEMP_FAILURE_RETRY(close(seckey_fd));

2527

close(seckey_fd);

1973

2528

}

1974

2529

}

1975

2530

1976

2531

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

1977

2532

int pubkey_fd = open(pubkey, O_RDONLY);

1978

2533

if(pubkey_fd == -1){

1990

2545

}

1991

2546

}

1992

2547

}

1993

TEMP_FAILURE_RETRY(close(pubkey_fd));

1994

}

1995

}

1996

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

1997

2574

/* Lower privileges */

1998

errno = 0;

1999

ret = seteuid(uid);

2000

if(ret == -1){

2001

perror_plus("seteuid");

2575

ret = lower_privileges();

2576

if(ret != 0){

2577

errno = ret;

2578

perror_plus("Failed to lower privileges");

2002

2579

}

2003

2580

}

2004

2581

}

2005

2582

2006

/* Remove empty interface names */

2583

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

2007

2584

{

2008

2585

char *interface = NULL;

2009

while((interface = argz_next(interfaces, interfaces_size,

2586

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

2010

2587

interface))){

2011

if(if_nametoindex(interface) == 0){

2012

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

2588

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

2589

and if_nametoindex(interface) == 0){

2590

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

2013

2591

fprintf_plus(stderr, "Not using nonexisting interface"

2014

2592

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

2015

2593

}

2016

argz_delete(&interfaces, &interfaces_size, interface);

2594

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

2017

2595

interface = NULL;

2018

2596

}

2019

2597

}

2021

2599

2022

2600

/* Run network hooks */

2023

2601

{

2024

2025

if(interfaces != NULL){

2026

interfaces_hooks = malloc(interfaces_size);

2602

if(mc.interfaces != NULL){

2603

interfaces_hooks = malloc(mc.interfaces_size);

2027

2604

if(interfaces_hooks == NULL){

2028

2605

perror_plus("malloc");

2029

2606

goto end;

2030

2607

}

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

}

2608

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

2609

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

2610

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

2040

2613

}

2041

2614

2042

2615

if(not debug){

2047

2620

from the signal handler */

2048

2621

/* Initialize the pseudo-RNG for Avahi */

2049

2622

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

2050

mc.simple_poll = avahi_simple_poll_new();

2051

if(mc.simple_poll == NULL){

2623

simple_poll = avahi_simple_poll_new();

2624

if(simple_poll == NULL){

2052

2625

fprintf_plus(stderr,

2053

2626

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

2054

2627

exitcode = EX_UNAVAILABLE;

2119

2692

}

2120

2693

2121

2694

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

2122

if(interfaces == NULL){

2123

struct dirent **direntries;

2695

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2124

2697

/* Look for any good interfaces */

2125

2698

ret = scandir(sys_class_net, &direntries, good_interface,

2126

2699

alphasort);

2127

2700

if(ret >= 1){

2128

2701

/* Add all found interfaces to interfaces list */

2129

2702

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

2130

ret_errno = argz_add(&interfaces, &interfaces_size,

2703

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

2131

2704

direntries[i]->d_name);

2132

2705

if(ret_errno != 0){

2706

errno = ret_errno;

2133

2707

perror_plus("argz_add");

2708

free(direntries[i]);

2134

2709

continue;

2135

2710

}

2136

2711

if(debug){

2137

2712

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

2138

2713

direntries[i]->d_name);

2139

2714

}

2715

free(direntries[i]);

2140

2716

}

2141

2717

free(direntries);

2142

2718

} else {

2143

free(direntries);

2719

if(ret == 0){

2720

free(direntries);

2721

}

2144

2722

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

2145

2723

exitcode = EXIT_FAILURE;

2146

2724

goto end;

2147

2725

}

2148

2726

}

2149

2727

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)){

2728

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

2729

{

2162

2730

char *interface = NULL;

2163

while((interface = argz_next(interfaces, interfaces_size,

2731

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

2164

2732

interface))){

2733

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

2734

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

2735

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

2736

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

2737

interface);

2738

interface = NULL;

2739

while((interface = argz_next(mc.interfaces,

2740

mc.interfaces_size, interface))){

2741

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

2742

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

2743

interface);

2744

interface = NULL;

2745

}

2746

}

2747

break;

2748

}

2165

2749

bool interface_was_up = interface_is_up(interface);

2166

ret = bring_up_interface(interface, delay);

2750

errno = bring_up_interface(interface, delay);

2167

2751

if(not interface_was_up){

2168

if(ret != 0){

2169

errno = ret;

2170

perror_plus("Failed to bring up interface");

2752

if(errno != 0){

2753

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

2754

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

2171

2755

} else {

2172

ret_errno = argz_add(&interfaces_to_take_down,

2173

&interfaces_to_take_down_size,

2174

interface);

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

2760

perror_plus("argz_add");

2761

}

2175

2762

}

2176

2763

}

2177

2764

}

2178

free(interfaces);

2179

interfaces = NULL;

2180

interfaces_size = 0;

2181

2765

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

2182

2766

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

2183

2767

}

2184

2768

}

2185

2769

2770

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

2771

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

2772

if(debug){

2773

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

2774

mc.interfaces);

2775

}

2776

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

2777

}

2778

2186

2779

if(quit_now){

2187

2780

goto end;

2188

2781

}

2189

2782

2190

ret = init_gnutls_global(pubkey, seckey);

2783

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

2191

2784

if(ret == -1){

2192

2785

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

2193

2786

exitcode = EX_UNAVAILABLE;

2200

2793

goto end;

2201

2794

}

2202

2795

2203

if(mkdtemp(tempdir) == NULL){

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

2204

2806

perror_plus("mkdtemp");

2205

2807

goto end;

2206

2808

}

2207

tempdir_created = true;

2208

2809

2209

2810

if(quit_now){

2210

2811

goto end;

2211

2812

}

2212

2813

2213

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

2814

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

2214

2815

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

2215

2816

exitcode = EX_UNAVAILABLE;

2216

2817

goto end;

2246

2847

exitcode = EX_USAGE;

2247

2848

goto end;

2248

2849

}

2249

2850

2250

2851

if(quit_now){

2251

2852

goto end;

2252

2853

}

2273

2874

}

2274

2875

2275

2876

while(not quit_now){

2276

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

2877

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

2878

&mc);

2277

2879

if(quit_now or ret == 0){

2278

2880

break;

2279

2881

}

2281

2883

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

2282

2884

(int)retry_interval);

2283

2885

}

2284

sleep((int)retry_interval);

2886

sleep((unsigned int)retry_interval);

2285

2887

}

2286

2888

2287

if (not quit_now){

2889

if(not quit_now){

2288

2890

exitcode = EXIT_SUCCESS;

2289

2891

}

2290

2892

2305

2907

config.publish_domain = 0;

2306

2908

2307

2909

/* Allocate a new server */

2308

mc.server = avahi_server_new(avahi_simple_poll_get

2309

(mc.simple_poll), &config, NULL,

2310

NULL, &ret_errno);

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2911

&config, NULL, NULL, &ret);

2311

2912

2312

2913

/* Free the Avahi configuration data */

2313

2914

avahi_server_config_free(&config);

2316

2917

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

2317

2918

if(mc.server == NULL){

2318

2919

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

2319

avahi_strerror(ret_errno));

2920

avahi_strerror(ret));

2320

2921

exitcode = EX_UNAVAILABLE;

2321

2922

goto end;

2322

2923

}

2328

2929

/* Create the Avahi service browser */

2329

2930

sb = avahi_s_service_browser_new(mc.server, if_index,

2330

2931

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2331

NULL, 0, browse_callback, NULL);

2932

NULL, 0, browse_callback,

2933

(void *)&mc);

2332

2934

if(sb == NULL){

2333

2935

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

2334

2936

avahi_strerror(avahi_server_errno(mc.server)));

2345

2947

if(debug){

2346

2948

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

2347

2949

}

2348

2349

ret = avahi_loop_with_timeout(mc.simple_poll,

2350

(int)(retry_interval * 1000));

2950

2951

ret = avahi_loop_with_timeout(simple_poll,

2952

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

2351

2953

if(debug){

2352

2954

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

2353

2955

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

2356

2958

end:

2357

2959

2358

2960

if(debug){

2359

fprintf_plus(stderr, "%s exiting\n", argv[0]);

2961

if(signal_received){

2962

fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",

2963

argv[0], signal_received,

2964

strsignal(signal_received));

2965

} else {

2966

fprintf_plus(stderr, "%s exiting\n", argv[0]);

2967

}

2360

2968

}

2361

2969

2362

2970

/* Cleanup things */

2971

free(mc.interfaces);

2972

2363

2973

if(sb != NULL)

2364

2974

avahi_s_service_browser_free(sb);

2365

2975

2366

2976

if(mc.server != NULL)

2367

2977

avahi_server_free(mc.server);

2368

2978

2369

if(mc.simple_poll != NULL)

2370

avahi_simple_poll_free(mc.simple_poll);

2979

if(simple_poll != NULL)

2980

avahi_simple_poll_free(simple_poll);

2371

2981

2372

2982

if(gnutls_initialized){

2373

2983

gnutls_certificate_free_credentials(mc.cred);

2374

gnutls_global_deinit();

2375

2984

gnutls_dh_params_deinit(mc.dh_params);

2376

2985

}

2377

2986

2385

2994

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

2386

2995

while(mc.current_server != NULL){

2387

2996

server *next = mc.current_server->next;

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic push

2999

#pragma GCC diagnostic ignored "-Wcast-qual"

3000

#endif

3001

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

3002

#ifdef __GNUC__

3003

#pragma GCC diagnostic pop

3004

#endif

2388

3005

free(mc.current_server);

2389

3006

mc.current_server = next;

2390

3007

}

2391

3008

}

2392

3009

2393

/* Re-raise priviliges */

3010

/* Re-raise privileges */

2394

3011

{

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();

3012

ret = raise_privileges();

3013

if(ret != 0){

3014

errno = ret;

3015

perror_plus("Failed to raise privileges");

3016

} else {

3017

3018

/* Run network hooks */

3019

run_network_hooks("stop", interfaces_hooks != NULL ?

3020

interfaces_hooks : "", delay);

3021

3022

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

3023

{

3024

char *interface = NULL;

3025

while((interface=argz_next(interfaces_to_take_down,

3026

interfaces_to_take_down_size,

3027

interface))){

3028

ret = take_down_interface(interface);

3029

if(ret != 0){

3030

errno = ret;

3031

perror_plus("Failed to take down interface");

3032

}

3033

}

3034

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

3035

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

3036

" down\n");

3037

}

3038

}

3039

}

3040

3041

ret = lower_privileges_permanently();

3042

if(ret != 0){

3043

errno = ret;

3044

perror_plus("Failed to lower privileges permanently");

3045

}

2420

3046

}

2421

3047

2422

3048

free(interfaces_to_take_down);

2423

3049

free(interfaces_hooks);

2424

3050

3051

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

3052

uintmax_t level){

3053

struct dirent **direntries = NULL;

3054

int dret;

3055

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

3056

O_RDONLY

3057

| O_NOFOLLOW

3058

| O_DIRECTORY

3059

| O_PATH));

3060

if(dir_fd == -1){

3061

perror_plus("open");

3062

}

3063

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

3064

notdotentries, alphasort);

3065

if(numentries >= 0){

3066

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

3067

if(debug){

3068

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

3069

dirname, direntries[i]->d_name);

3070

}

3071

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

3072

if(dret == -1){

3073

if(errno == EISDIR){

3074

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

3075

AT_REMOVEDIR);

3076

}

3077

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

3078

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

3079

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

3080

/* Recurse only in this special case */

3081

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

3082

dret = 0;

3083

}

3084

if(dret == -1){

3085

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

3086

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

3087

}

3088

}

3089

free(direntries[i]);

3090

}

3091

3092

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

3093

free(direntries);

3094

if(numentries == -1){

3095

perror_plus("scandirat");

3096

}

3097

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3098

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

3099

perror_plus("rmdir");

3100

}

3101

} else {

3102

perror_plus("scandirat");

3103

}

3104

close(dir_fd);

3105

}

3106

2425

3107

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

2426

if(tempdir_created){

2427

struct dirent **direntries = NULL;

2428

struct dirent *direntry = NULL;

2429

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

2430

alphasort);

2431

if (numentries > 0){

2432

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

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

}

3108

if(tempdir != NULL){

3109

clean_dir_at(-1, tempdir, 0);

2459

3110

}

2460

3111

2461

3112

if(quit_now){