/mandos/trunk : revision 594.1.4

9

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

10

*

11

* Everything else is

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13

12

13

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*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

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#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 */

46

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

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strtof(), abort() */

48

#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() */

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#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,

64

63

strtoimax() */

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#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 <assert.h> /* assert() */

65

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

70

66

program_invocation_short_name */

71

67

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

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68

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

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73

*/

78

74

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

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

80

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

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unlinkat() */

82

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

76

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

77

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

83

78

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

84

79

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

85

80

argp_state, struct argp,

97

92

argz_delete(), argz_append(),

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93

argz_stringify(), argz_add(),

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94

argz_count() */

100

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

101

EAI_SYSTEM, gai_strerror() */

102

95

103

96

#ifdef __linux__

104

97

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

146

139

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

147

140

char *connect_to = NULL;

148

141

const char *hookdir = HOOKDIR;

149

int hookdir_fd = -1;

150

142

uid_t uid = 65534;

151

143

gid_t gid = 65534;

152

144

153

145

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

154

146

typedef struct server{

155

147

const char *ip;

156

in_port_t port;

148

uint16_t port;

157

149

AvahiIfIndex if_index;

158

150

int af;

159

151

struct timespec last_seen;

163

155

164

156

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

165

157

typedef struct {

158

AvahiSimplePoll *simple_poll;

166

159

AvahiServer *server;

167

160

gnutls_certificate_credentials_t cred;

168

161

unsigned int dh_bits;

170

163

const char *priority;

171

164

gpgme_ctx_t ctx;

172

165

server *current_server;

173

char *interfaces;

174

size_t interfaces_size;

175

166

} mandos_context;

176

167

177

/* global so signal handler can reach it*/

178

AvahiSimplePoll *simple_poll;

168

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

169

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

170

.dh_bits = 1024, .priority = "SECURE256"

171

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

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.current_server = NULL };

179

173

180

174

sig_atomic_t quit_now = 0;

181

175

int signal_received = 0;

189

183

perror(print_text);

190

184

}

191

185

192

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

186

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

193

187

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

194

188

va_list ap;

195

189

va_start (ap, format);

196

190

197

191

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

198

192

program_invocation_short_name));

199

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

193

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

200

194

}

201

195

202

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/*

204

198

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

205

199

* "buffer_length" is how much is already used.

206

200

*/

207

__attribute__((nonnull, warn_unused_result))

208

201

size_t incbuffer(char **buffer, size_t buffer_length,

209

202

size_t buffer_capacity){

210

203

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;

204

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

205

if(buffer == NULL){

217

206

return 0;

218

207

}

219

*buffer = new_buf;

220

208

buffer_capacity += BUFFER_SIZE;

221

209

}

222

210

return buffer_capacity;

223

211

}

224

212

225

213

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

226

__attribute__((nonnull, warn_unused_result))

227

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

228

int af, server **current_server){

214

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

215

int af){

229

216

int ret;

230

217

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

231

218

if(new_server == NULL){

238

225

.af = af };

239

226

if(new_server->ip == NULL){

240

227

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

228

return false;

257

229

}

258

230

/* Special case of first server */

259

if(*current_server == NULL){

231

if (mc.current_server == NULL){

260

232

new_server->next = new_server;

261

233

new_server->prev = new_server;

262

*current_server = new_server;

234

mc.current_server = new_server;

235

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

263

236

} else {

264

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

265

new_server->next = *current_server;

266

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

237

new_server->next = mc.current_server;

238

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

267

239

new_server->prev->next = new_server;

268

(*current_server)->prev = new_server;

240

mc.current_server->prev = new_server;

241

}

242

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

243

if(ret == -1){

244

perror_plus("clock_gettime");

245

return false;

269

246

}

270

247

return true;

271

248

}

273

250

/*

274

251

* Initialize GPGME.

275

252

*/

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){

253

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

254

const char *tempdir){

281

255

gpgme_error_t rc;

282

256

gpgme_engine_info_t engine_info;

283

257

258

284

259

/*

285

260

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

286

261

*/

287

bool import_key(const char * const filename){

262

bool import_key(const char *filename){

288

263

int ret;

289

264

int fd;

290

265

gpgme_data_t pgp_data;

302

277

return false;

303

278

}

304

279

305

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

280

rc = gpgme_op_import(mc.ctx, pgp_data);

306

281

if(rc != GPG_ERR_NO_ERROR){

307

282

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

308

283

gpgme_strsource(rc), gpgme_strerror(rc));

309

284

return false;

310

285

}

311

286

312

ret = close(fd);

287

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

313

288

if(ret == -1){

314

289

perror_plus("close");

315

290

}

352

327

}

353

328

354

329

/* Create new GPGME "context" */

355

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

330

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

356

331

if(rc != GPG_ERR_NO_ERROR){

357

332

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

358

333

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

371

346

* Decrypt OpenPGP data.

372

347

* Returns -1 on error

373

348

*/

374

__attribute__((nonnull, warn_unused_result))

375

349

static ssize_t pgp_packet_decrypt(const char *cryptotext,

376

350

size_t crypto_size,

377

char **plaintext,

378

mandos_context *mc){

351

char **plaintext){

379

352

gpgme_data_t dh_crypto, dh_plain;

380

353

gpgme_error_t rc;

381

354

ssize_t ret;

407

380

408

381

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

409

382

data buffer */

410

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

383

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

411

384

if(rc != GPG_ERR_NO_ERROR){

412

385

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

413

386

gpgme_strsource(rc), gpgme_strerror(rc));

414

387

plaintext_length = -1;

415

388

if(debug){

416

389

gpgme_decrypt_result_t result;

417

result = gpgme_op_decrypt_result(mc->ctx);

390

result = gpgme_op_decrypt_result(mc.ctx);

418

391

if(result == NULL){

419

392

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

420

393

} else {

497

470

return plaintext_length;

498

471

}

499

472

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){

509

const char *ret = gnutls_strerror(value);

510

return safe_string(ret);

473

static const char * safer_gnutls_strerror(int value){

474

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

475

-Wunreachable-code */

476

if(ret == NULL)

477

ret = "(unknown)";

478

return ret;

511

479

}

512

480

513

481

/* GnuTLS log function callback */

514

__attribute__((nonnull))

515

482

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

516

483

const char* string){

517

484

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

518

485

}

519

486

520

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

521

487

static int init_gnutls_global(const char *pubkeyfilename,

522

const char *seckeyfilename,

523

const char *dhparamsfilename,

524

mandos_context *mc){

488

const char *seckeyfilename){

525

489

int ret;

526

unsigned int uret;

527

490

528

491

if(debug){

529

492

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

530

493

}

531

494

495

ret = gnutls_global_init();

496

if(ret != GNUTLS_E_SUCCESS){

497

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

498

safer_gnutls_strerror(ret));

499

return -1;

500

}

501

532

502

if(debug){

533

503

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

534

504

* - GnuTLS manual

538

508

}

539

509

540

510

/* OpenPGP credentials */

541

ret = gnutls_certificate_allocate_credentials(&mc->cred);

511

ret = gnutls_certificate_allocate_credentials(&mc.cred);

542

512

if(ret != GNUTLS_E_SUCCESS){

543

513

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

544

514

safer_gnutls_strerror(ret));

515

gnutls_global_deinit();

545

516

return -1;

546

517

}

547

518

553

524

}

554

525

555

526

ret = gnutls_certificate_set_openpgp_key_file

556

(mc->cred, pubkeyfilename, seckeyfilename,

527

(mc.cred, pubkeyfilename, seckeyfilename,

557

528

GNUTLS_OPENPGP_FMT_BASE64);

558

529

if(ret != GNUTLS_E_SUCCESS){

559

530

fprintf_plus(stderr,

565

536

}

566

537

567

538

/* GnuTLS server initialization */

568

ret = gnutls_dh_params_init(&mc->dh_params);

539

ret = gnutls_dh_params_init(&mc.dh_params);

569

540

if(ret != GNUTLS_E_SUCCESS){

570

541

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

571

542

" initialization: %s\n",

572

543

safer_gnutls_strerror(ret));

573

544

goto globalfail;

574

545

}

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);

546

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

547

if(ret != GNUTLS_E_SUCCESS){

548

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

549

safer_gnutls_strerror(ret));

550

goto globalfail;

551

}

552

553

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

748

554

749

555

return 0;

750

556

751

557

globalfail:

752

558

753

gnutls_certificate_free_credentials(mc->cred);

754

gnutls_dh_params_deinit(mc->dh_params);

559

gnutls_certificate_free_credentials(mc.cred);

560

gnutls_global_deinit();

561

gnutls_dh_params_deinit(mc.dh_params);

755

562

return -1;

756

563

}

757

564

758

__attribute__((nonnull, warn_unused_result))

759

static int init_gnutls_session(gnutls_session_t *session,

760

mandos_context *mc){

565

static int init_gnutls_session(gnutls_session_t *session){

761

566

int ret;

762

567

/* GnuTLS session creation */

763

568

do {

775

580

{

776

581

const char *err;

777

582

do {

778

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

583

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

779

584

if(quit_now){

780

585

gnutls_deinit(*session);

781

586

return -1;

792

597

793

598

do {

794

599

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

795

mc->cred);

600

mc.cred);

796

601

if(quit_now){

797

602

gnutls_deinit(*session);

798

603

return -1;

808

613

/* ignore client certificate if any. */

809

614

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

810

615

616

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

617

811

618

return 0;

812

619

}

813

620

815

622

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

816

623

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

817

624

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

625

/* Called when a Mandos server is found */

1037

__attribute__((nonnull, warn_unused_result))

1038

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

626

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

1039

627

AvahiIfIndex if_index,

1040

int af, mandos_context *mc){

628

int af){

1041

629

int ret, tcp_sd = -1;

1042

630

ssize_t sret;

1043

struct sockaddr_storage to;

631

union {

632

struct sockaddr_in in;

633

struct sockaddr_in6 in6;

634

} to;

1044

635

char *buffer = NULL;

1045

636

char *decrypted_buffer = NULL;

1046

637

size_t buffer_length = 0;

1049

640

int retval = -1;

1050

641

gnutls_session_t session;

1051

642

int pf; /* Protocol family */

1052

bool route_added = false;

1053

643

1054

644

errno = 0;

1055

645

1071

661

return -1;

1072

662

}

1073

663

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);

664

ret = init_gnutls_session(&session);

1107

665

if(ret != 0){

1108

666

return -1;

1109

667

}

1110

668

1111

669

if(debug){

1112

670

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

1113

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

671

PRIu16 "\n", ip, port);

1114

672

}

1115

673

1116

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

674

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

675

if(tcp_sd < 0){

1118

676

int e = errno;

1119

677

perror_plus("socket");

1126

684

goto mandos_end;

1127

685

}

1128

686

687

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

1129

688

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);

689

to.in6.sin6_family = (sa_family_t)af;

690

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

1133

691

} 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);

692

to.in.sin_family = (sa_family_t)af;

693

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

1137

694

}

1138

695

if(ret < 0 ){

1139

696

int e = errno;

1148

705

goto mandos_end;

1149

706

}

1150

707

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)){

708

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

709

-Wconversion and

710

-Wunreachable-code */

711

712

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

713

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

714

-Wunreachable-code*/

1154

715

if(if_index == AVAHI_IF_UNSPEC){

1155

716

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

1156

717

" incomplete without a network interface\n");

1158

719

goto mandos_end;

1159

720

}

1160

721

/* Set the network interface number as scope */

1161

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

722

to.in6.sin6_scope_id = (uint32_t)if_index;

1162

723

}

1163

724

} else {

1164

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

725

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

726

-Wconversion and

727

-Wunreachable-code */

1165

728

}

1166

729

1167

730

if(quit_now){

1175

738

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

1176

739

perror_plus("if_indextoname");

1177

740

} else {

1178

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

1179

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

741

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

742

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

1180

743

}

1181

744

} else {

1182

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

1183

ip, (uintmax_t)port);

745

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

746

ip, port);

1184

747

}

1185

748

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1186

749

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;

750

const char *pcret;

751

if(af == AF_INET6){

752

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

753

sizeof(addrstr));

754

} else {

755

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

756

sizeof(addrstr));

757

}

758

if(pcret == NULL){

759

perror_plus("inet_ntop");

760

} else {

761

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

762

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

763

}

764

}

765

}

766

767

if(quit_now){

768

errno = EINTR;

769

goto mandos_end;

770

}

771

772

if(af == AF_INET6){

773

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

774

} else {

775

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

776

}

777

if(ret < 0){

778

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

779

int e = errno;

780

perror_plus("connect");

781

errno = e;

782

}

783

goto mandos_end;

784

}

785

786

if(quit_now){

787

errno = EINTR;

788

goto mandos_end;

1267

789

}

1268

790

1269

791

const char *out = mandos_protocol_version;

1420

942

if(buffer_length > 0){

1421

943

ssize_t decrypted_buffer_size;

1422

944

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1423

&decrypted_buffer, mc);

945

&decrypted_buffer);

1424

946

if(decrypted_buffer_size >= 0){

1425

947

1426

948

written = 0;

1452

974

1453

975

mandos_end:

1454

976

{

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

977

int e = errno;

1462

978

free(decrypted_buffer);

1463

979

free(buffer);

1464

980

if(tcp_sd >= 0){

1465

ret = close(tcp_sd);

981

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

1466

982

}

1467

983

if(ret == -1){

1468

984

if(e == 0){

1480

996

return retval;

1481

997

}

1482

998

1483

__attribute__((nonnull))

1484

999

static void resolve_callback(AvahiSServiceResolver *r,

1485

1000

AvahiIfIndex interface,

1486

1001

AvahiProtocol proto,

1494

1009

AVAHI_GCC_UNUSED AvahiStringList *txt,

1495

1010

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1496

1011

flags,

1497

void *mc){

1498

if(r == NULL){

1499

return;

1500

}

1012

AVAHI_GCC_UNUSED void* userdata){

1013

assert(r);

1501

1014

1502

1015

/* Called whenever a service has been resolved successfully or

1503

1016

timed out */

1504

1017

1505

1018

if(quit_now){

1506

avahi_s_service_resolver_free(r);

1507

1019

return;

1508

1020

}

1509

1021

1513

1025

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

1514

1026

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

1515

1027

domain,

1516

avahi_strerror(avahi_server_errno

1517

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

1028

avahi_strerror(avahi_server_errno(mc.server)));

1518

1029

break;

1519

1030

1520

1031

case AVAHI_RESOLVER_FOUND:

1526

1037

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

1527

1038

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

1528

1039

}

1529

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

1530

interface,

1531

avahi_proto_to_af(proto),

1532

mc);

1040

int ret = start_mandos_communication(ip, port, interface,

1041

avahi_proto_to_af(proto));

1533

1042

if(ret == 0){

1534

avahi_simple_poll_quit(simple_poll);

1043

avahi_simple_poll_quit(mc.simple_poll);

1535

1044

} else {

1536

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

1537

avahi_proto_to_af(proto),

1538

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

1045

if(not add_server(ip, port, interface,

1046

avahi_proto_to_af(proto))){

1539

1047

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

1540

1048

" list\n", name);

1541

1049

}

1554

1062

const char *domain,

1555

1063

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1556

1064

flags,

1557

void *mc){

1558

if(b == NULL){

1559

return;

1560

}

1065

AVAHI_GCC_UNUSED void* userdata){

1066

assert(b);

1561

1067

1562

1068

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

1563

1069

is removed from the LAN */

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

1453

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);

1930

}

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){

1454

} else {

1455

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

1456

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

1457

direntry = direntries[i];

1458

char *fullname = NULL;

1459

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

1460

if(ret < 0){

1977

1461

perror_plus("asprintf");

1978

_exit(EX_OSERR);

1979

}

1980

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

1981

if(ret == -1){

1462

continue;

1463

}

1464

if(debug){

1465

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

1466

direntry->d_name);

1467

}

1468

pid_t hook_pid = fork();

1469

if(hook_pid == 0){

1470

/* Child */

1471

/* Raise privileges */

1472

raise_privileges_permanently();

1473

/* Set group */

1474

errno = 0;

1475

ret = setgid(0);

1476

if(ret == -1){

1477

perror_plus("setgid");

1478

}

1479

/* Reset supplementary groups */

1480

errno = 0;

1481

ret = setgroups(0, NULL);

1482

if(ret == -1){

1483

perror_plus("setgroups");

1484

}

1485

dup2(devnull, STDIN_FILENO);

1486

close(devnull);

1487

dup2(STDERR_FILENO, STDOUT_FILENO);

1488

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

1489

if(ret == -1){

1490

perror_plus("setenv");

1491

_exit(EX_OSERR);

1492

}

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

char *delaystring;

1509

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

1510

if(ret == -1){

1511

perror_plus("asprintf");

1512

_exit(EX_OSERR);

1513

}

1514

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

1515

if(ret == -1){

1516

free(delaystring);

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1982

1520

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;

1521

if(connect_to != NULL){

1522

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

1523

if(ret == -1){

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1527

}

1528

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

1529

perror_plus("execl");

1530

_exit(EXIT_FAILURE);

1531

}

2051

1532

} 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);

1533

int status;

1534

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

1535

perror_plus("waitpid");

1536

free(fullname);

1537

continue;

1538

}

1539

if(WIFEXITED(status)){

1540

if(WEXITSTATUS(status) != 0){

1541

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

1542

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

1543

WEXITSTATUS(status));

1544

free(fullname);

1545

continue;

1546

}

1547

} else if(WIFSIGNALED(status)){

1548

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

1549

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

1550

WTERMSIG(status));

1551

free(fullname);

1552

continue;

1553

} else {

1554

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

1555

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

1556

free(fullname);

1557

continue;

1558

}

1559

}

1560

free(fullname);

1561

if(debug){

1562

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

1563

direntry->d_name);

1564

}

1565

}

1566

close(devnull);

1567

}

1568

return true;

2071

1569

}

2072

1570

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;

1571

error_t bring_up_interface(const char *const interface,

1572

const float delay){

1573

int sd = -1;

1574

error_t old_errno = errno;

1575

error_t ret_errno = 0;

1576

int ret, ret_setflags;

2078

1577

struct ifreq network;

2079

1578

unsigned int if_index = if_nametoindex(interface);

2080

1579

if(if_index == 0){

2089

1588

}

2090

1589

2091

1590

if(not interface_is_up(interface)){

2092

int ret_errno = 0;

2093

int ioctl_errno = 0;

2094

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

1591

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

2095

1592

ret_errno = errno;

2096

1593

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

2097

1594

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

2098

errno = old_errno;

2099

1595

return ret_errno;

2100

1596

}

2101

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

1597

network.ifr_flags |= IFF_UP;

2102

1598

2103

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

2104

if(sd == -1){

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

2105

1601

ret_errno = errno;

2106

1602

perror_plus("socket");

2107

1603

errno = old_errno;

2108

1604

return ret_errno;

2109

1605

}

2110

1606

2111

1607

if(quit_now){

2112

ret = close(sd);

2113

if(ret == -1){

2114

perror_plus("close");

2115

}

1608

close(sd);

2116

1609

errno = old_errno;

2117

1610

return EINTR;

2118

1611

}

2122

1615

interface);

2123

1616

}

2124

1617

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

}

1618

/* Raise priviliges */

1619

raise_privileges();

2131

1620

2132

1621

#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

}

1622

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1623

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

1624

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

1625

bool restore_loglevel = true;

1626

if(ret_linux == -1){

1627

restore_loglevel = false;

1628

perror_plus("klogctl");

2144

1629

}

2145

1630

#endif /* __linux__ */

2146

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

2147

ioctl_errno = errno;

1631

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

1632

ret_errno = errno;

2148

1633

#ifdef __linux__

2149

1634

if(restore_loglevel){

2150

1635

ret_linux = klogctl(7, NULL, 0);

2154

1639

}

2155

1640

#endif /* __linux__ */

2156

1641

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

}

1642

/* Lower privileges */

1643

lower_privileges();

2166

1644

2167

1645

/* Close the socket */

2168

ret = close(sd);

1646

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

2169

1647

if(ret == -1){

2170

1648

perror_plus("close");

2171

1649

}

2172

1650

2173

1651

if(ret_setflags == -1){

2174

errno = ioctl_errno;

1652

errno = ret_errno;

2175

1653

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2176

1654

errno = old_errno;

2177

return ioctl_errno;

1655

return ret_errno;

2178

1656

}

2179

1657

} else if(debug){

2180

1658

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

2198

1676

return 0;

2199

1677

}

2200

1678

2201

__attribute__((nonnull, warn_unused_result))

2202

int take_down_interface(const char *const interface){

2203

int old_errno = errno;

1679

error_t take_down_interface(const char *const interface){

1680

int sd = -1;

1681

error_t old_errno = errno;

1682

error_t ret_errno = 0;

1683

int ret, ret_setflags;

2204

1684

struct ifreq network;

2205

1685

unsigned int if_index = if_nametoindex(interface);

2206

1686

if(if_index == 0){

2209

1689

return ENXIO;

2210

1690

}

2211

1691

if(interface_is_up(interface)){

2212

int ret_errno = 0;

2213

int ioctl_errno = 0;

2214

1692

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

2215

1693

ret_errno = errno;

2216

1694

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

2217

1695

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

2218

errno = old_errno;

2219

1696

return ret_errno;

2220

1697

}

2221

1698

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

2222

1699

2223

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

2224

if(sd == -1){

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

2225

1702

ret_errno = errno;

2226

1703

perror_plus("socket");

2227

1704

errno = old_errno;

2233

1710

interface);

2234

1711

}

2235

1712

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

}

1713

/* Raise priviliges */

1714

raise_privileges();

1715

1716

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

1717

ret_errno = errno;

1718

1719

/* Lower privileges */

1720

lower_privileges();

2255

1721

2256

1722

/* Close the socket */

2257

int ret = close(sd);

1723

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

2258

1724

if(ret == -1){

2259

1725

perror_plus("close");

2260

1726

}

2261

1727

2262

1728

if(ret_setflags == -1){

2263

errno = ioctl_errno;

1729

errno = ret_errno;

2264

1730

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2265

1731

errno = old_errno;

2266

return ioctl_errno;

1732

return ret_errno;

2267

1733

}

2268

1734

} else if(debug){

2269

1735

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

2275

1741

}

2276

1742

2277

1743

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

1744

AvahiSServiceBrowser *sb = NULL;

2284

1745

error_t ret_errno;

2285

1746

int ret;

2286

1747

intmax_t tmpmax;

2287

1748

char *tmp;

2288

1749

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

2289

1752

char *interfaces_to_take_down = NULL;

2290

1753

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;

1754

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

1755

bool tempdir_created = false;

2294

1756

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2295

1757

const char *seckey = PATHDIR "/" SECKEY;

2296

1758

const char *pubkey = PATHDIR "/" PUBKEY;

2297

const char *dh_params_file = NULL;

2298

1759

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

2299

1761

2300

1762

bool gnutls_initialized = false;

2301

1763

bool gpgme_initialized = false;

2353

1815

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

2354

1816

" Diffie-Hellman key exchange",

2355

1817

.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

1818

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

2362

1819

.arg = "STRING",

2363

1820

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

2397

1854

connect_to = arg;

2398

1855

break;

2399

1856

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

2400

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

2401

arg, (int)',');

1857

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

1858

(int)',');

2402

1859

if(ret_errno != 0){

2403

1860

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

2404

1861

}

2418

1875

}

2419

1876

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

2420

1877

break;

2421

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

2422

dh_params_file = arg;

2423

break;

2424

1878

case 130: /* --priority */

2425

1879

mc.priority = arg;

2426

1880

break;

2466

1920

.args_doc = "",

2467

1921

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

2468

1922

" 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){

1923

ret = argp_parse(&argp, argc, argv,

1924

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1925

switch(ret){

2472

1926

case 0:

2473

1927

break;

2474

1928

case ENOMEM:

2475

1929

default:

2476

errno = ret_errno;

1930

errno = ret;

2477

1931

perror_plus("argp_parse");

2478

1932

exitcode = EX_OSERR;

2479

1933

goto end;

2482

1936

goto end;

2483

1937

}

2484

1938

}

2485

1939

2486

1940

{

2487

1941

/* Work around Debian bug #633582:

2488

1942

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

2489

1943

2490

/* Re-raise privileges */

2491

ret = raise_privileges();

2492

if(ret != 0){

2493

errno = ret;

2494

perror_plus("Failed to raise privileges");

2495

} else {

1944

/* Re-raise priviliges */

1945

if(raise_privileges() == 0){

2496

1946

struct stat st;

2497

1947

2498

1948

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

2512

1962

}

2513

1963

}

2514

1964

}

2515

close(seckey_fd);

1965

TEMP_FAILURE_RETRY(close(seckey_fd));

2516

1966

}

2517

1967

}

2518

1968

2519

1969

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

2520

1970

int pubkey_fd = open(pubkey, O_RDONLY);

2521

1971

if(pubkey_fd == -1){

2533

1983

}

2534

1984

}

2535

1985

}

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

1986

TEMP_FAILURE_RETRY(close(pubkey_fd));

1987

}

1988

}

1989

2562

1990

/* Lower privileges */

2563

ret = lower_privileges();

2564

if(ret != 0){

2565

errno = ret;

2566

perror_plus("Failed to lower privileges");

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2567

1995

}

2568

1996

}

2569

1997

}

2570

1998

2571

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

1999

/* Remove empty interface names */

2572

2000

{

2573

2001

char *interface = NULL;

2574

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

2002

while((interface = argz_next(interfaces, interfaces_size,

2575

2003

interface))){

2576

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

2577

and if_nametoindex(interface) == 0){

2578

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

2004

if(if_nametoindex(interface) == 0){

2005

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

2579

2006

fprintf_plus(stderr, "Not using nonexisting interface"

2580

2007

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

2581

2008

}

2582

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

2009

argz_delete(&interfaces, &interfaces_size, interface);

2583

2010

interface = NULL;

2584

2011

}

2585

2012

}

2587

2014

2588

2015

/* Run network hooks */

2589

2016

{

2590

if(mc.interfaces != NULL){

2591

interfaces_hooks = malloc(mc.interfaces_size);

2592

if(interfaces_hooks == NULL){

2593

perror_plus("malloc");

2594

goto end;

2595

}

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);

2017

ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,

2018

interfaces, interfaces_size);

2019

if(ret_errno != 0){

2020

errno = ret_errno;

2021

perror_plus("argz_append");

2022

goto end;

2023

}

2024

argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');

2025

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

2026

goto end;

2027

}

2601

2028

}

2602

2029

2603

2030

if(not debug){

2608

2035

from the signal handler */

2609

2036

/* Initialize the pseudo-RNG for Avahi */

2610

2037

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

2611

simple_poll = avahi_simple_poll_new();

2612

if(simple_poll == NULL){

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2613

2040

fprintf_plus(stderr,

2614

2041

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

2615

2042

exitcode = EX_UNAVAILABLE;

2680

2107

}

2681

2108

2682

2109

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

2683

if(mc.interfaces == NULL){

2684

struct dirent **direntries = NULL;

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2685

2112

/* Look for any good interfaces */

2686

2113

ret = scandir(sys_class_net, &direntries, good_interface,

2687

2114

alphasort);

2688

2115

if(ret >= 1){

2689

2116

/* Add all found interfaces to interfaces list */

2690

2117

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

2691

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2692

2119

direntries[i]->d_name);

2693

2120

if(ret_errno != 0){

2694

errno = ret_errno;

2695

2121

perror_plus("argz_add");

2696

free(direntries[i]);

2697

2122

continue;

2698

2123

}

2699

2124

if(debug){

2700

2125

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

2701

2126

direntries[i]->d_name);

2702

2127

}

2703

free(direntries[i]);

2704

2128

}

2705

2129

free(direntries);

2706

2130

} else {

2707

if(ret == 0){

2708

free(direntries);

2709

}

2131

free(direntries);

2710

2132

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

2711

2133

exitcode = EXIT_FAILURE;

2712

2134

goto end;

2713

2135

}

2714

2136

}

2715

2137

2716

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

2717

{

2138

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

2139

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

2140

if(debug){

2141

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

2142

interfaces);

2143

}

2144

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2145

}

2146

2147

/* Bring up interfaces which are down */

2148

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

2149

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

2718

2150

char *interface = NULL;

2719

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

2151

while((interface = argz_next(interfaces, interfaces_size,

2720

2152

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

2153

bool interface_was_up = interface_is_up(interface);

2738

errno = bring_up_interface(interface, delay);

2154

ret = bring_up_interface(interface, delay);

2739

2155

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));

2156

if(ret != 0){

2157

errno = ret;

2158

perror_plus("Failed to bring up interface");

2743

2159

} 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

}

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

interface);

2750

2163

}

2751

2164

}

2752

2165

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2753

2169

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

2754

2170

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

2755

2171

}

2756

2172

}

2757

2173

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

2174

if(quit_now){

2768

2175

goto end;

2769

2176

}

2770

2177

2771

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

2178

ret = init_gnutls_global(pubkey, seckey);

2772

2179

if(ret == -1){

2773

2180

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

2774

2181

exitcode = EX_UNAVAILABLE;

2781

2188

goto end;

2782

2189

}

2783

2190

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){

2191

if(mkdtemp(tempdir) == NULL){

2794

2192

perror_plus("mkdtemp");

2795

2193

goto end;

2796

2194

}

2195

tempdir_created = true;

2797

2196

2798

2197

if(quit_now){

2799

2198

goto end;

2800

2199

}

2801

2200

2802

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

2201

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

2803

2202

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

2804

2203

exitcode = EX_UNAVAILABLE;

2805

2204

goto end;

2826

2225

goto end;

2827

2226

}

2828

2227

2829

in_port_t port;

2228

uint16_t port;

2830

2229

errno = 0;

2831

2230

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

2832

2231

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

2833

or tmpmax != (in_port_t)tmpmax){

2232

or tmpmax != (uint16_t)tmpmax){

2834

2233

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

2835

2234

exitcode = EX_USAGE;

2836

2235

goto end;

2837

2236

}

2838

2237

2839

2238

if(quit_now){

2840

2239

goto end;

2841

2240

}

2842

2241

2843

port = (in_port_t)tmpmax;

2242

port = (uint16_t)tmpmax;

2844

2243

*address = '\0';

2845

2244

/* Colon in address indicates IPv6 */

2846

2245

int af;

2862

2261

}

2863

2262

2864

2263

while(not quit_now){

2865

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

2866

&mc);

2264

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

2867

2265

if(quit_now or ret == 0){

2868

2266

break;

2869

2267

}

2871

2269

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

2872

2270

(int)retry_interval);

2873

2271

}

2874

sleep((unsigned int)retry_interval);

2272

sleep((int)retry_interval);

2875

2273

}

2876

2274

2877

if(not quit_now){

2275

if (not quit_now){

2878

2276

exitcode = EXIT_SUCCESS;

2879

2277

}

2880

2278

2895

2293

config.publish_domain = 0;

2896

2294

2897

2295

/* Allocate a new server */

2898

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2899

&config, NULL, NULL, &ret);

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2900

2299

2901

2300

/* Free the Avahi configuration data */

2902

2301

avahi_server_config_free(&config);

2905

2304

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

2906

2305

if(mc.server == NULL){

2907

2306

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

2908

avahi_strerror(ret));

2307

avahi_strerror(ret_errno));

2909

2308

exitcode = EX_UNAVAILABLE;

2910

2309

goto end;

2911

2310

}

2917

2316

/* Create the Avahi service browser */

2918

2317

sb = avahi_s_service_browser_new(mc.server, if_index,

2919

2318

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2920

NULL, 0, browse_callback,

2921

(void *)&mc);

2319

NULL, 0, browse_callback, NULL);

2922

2320

if(sb == NULL){

2923

2321

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

2924

2322

avahi_strerror(avahi_server_errno(mc.server)));

2935

2333

if(debug){

2936

2334

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

2937

2335

}

2938

2939

ret = avahi_loop_with_timeout(simple_poll,

2940

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

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2941

2339

if(debug){

2942

2340

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

2943

2341

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

2950

2348

}

2951

2349

2952

2350

/* Cleanup things */

2953

free(mc.interfaces);

2954

2955

2351

if(sb != NULL)

2956

2352

avahi_s_service_browser_free(sb);

2957

2353

2958

2354

if(mc.server != NULL)

2959

2355

avahi_server_free(mc.server);

2960

2356

2961

if(simple_poll != NULL)

2962

avahi_simple_poll_free(simple_poll);

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2963

2359

2964

2360

if(gnutls_initialized){

2965

2361

gnutls_certificate_free_credentials(mc.cred);

2362

gnutls_global_deinit();

2966

2363

gnutls_dh_params_deinit(mc.dh_params);

2967

2364

}

2968

2365

2976

2373

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

2977

2374

while(mc.current_server != NULL){

2978

2375

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

2376

free(mc.current_server);

2988

2377

mc.current_server = next;

2989

2378

}

2990

2379

}

2991

2380

2992

/* Re-raise privileges */

2381

/* Re-raise priviliges */

2993

2382

{

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

}

2383

raise_privileges();

2384

2385

/* Run network hooks */

2386

run_network_hooks("stop", interfaces_hooks, delay);

2387

2388

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

2389

{

2390

char *interface = NULL;

2391

while((interface=argz_next(interfaces_to_take_down,

2392

interfaces_to_take_down_size,

2393

interface))){

2394

ret_errno = take_down_interface(interface);

2395

if(ret_errno != 0){

2396

errno = ret_errno;

2397

perror_plus("Failed to take down interface");

2398

}

2399

}

2400

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

2401

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

2402

" down\n");

2403

}

2404

}

2405

2406

lower_privileges_permanently();

3028

2407

}

3029

2408

3030

2409

free(interfaces_to_take_down);

3031

2410

free(interfaces_hooks);

3032

2411

3033

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

3034

uintmax_t level){

2412

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

2413

if(tempdir_created){

3035

2414

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){

2415

struct dirent *direntry = NULL;

2416

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

2417

alphasort);

2418

if (numentries > 0){

3048

2419

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);

2420

direntry = direntries[i];

2421

char *fullname = NULL;

2422

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

2423

direntry->d_name);

2424

if(ret < 0){

2425

perror_plus("asprintf");

2426

continue;

2427

}

2428

ret = remove(fullname);

2429

if(ret == -1){

2430

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

2431

strerror(errno));

2432

}

2433

free(fullname);

2434

}

2435

}

2436

2437

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

2438

free(direntries);

2439

if (numentries == -1){

2440

perror_plus("scandir");

2441

}

2442

ret = rmdir(tempdir);

2443

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

2444

perror_plus("rmdir");

2445

}

3092

2446

}

3093

2447

3094

2448

if(quit_now){