/mandos/trunk : revision 505.3.13

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

41

42

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

43

stdout, ferror() */

44

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

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

strtof(), abort() */

48

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

49

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

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asprintf(), strncpy(), strsignal()

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*/

49

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

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

52

51

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

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52

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

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53

sockaddr_in6, PF_INET6,

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55

opendir(), DIR */

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56

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

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

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inet_pton(), connect(),

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getnameinfo() */

61

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

58

inet_pton(), connect() */

59

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

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60

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

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61

*/

64

62

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

65

63

strtoimax() */

66

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

69

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

70

ENOTEMPTY,

64

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

65

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

71

66

program_invocation_short_name */

72

67

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

73

68

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

78

73

*/

79

74

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

80

75

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

81

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

82

unlinkat() */

83

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

76

setgid(), pause() */

77

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

84

78

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

85

79

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

86

80

argp_state, struct argp,

93

87

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

94

88

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

95

89

WEXITSTATUS(), WTERMSIG() */

96

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

97

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

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argz_delete(), argz_append(),

99

argz_stringify(), argz_add(),

100

argz_count() */

101

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

102

EAI_SYSTEM, gai_strerror() */

103

90

104

91

#ifdef __linux__

105

92

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

147

134

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

148

135

char *connect_to = NULL;

149

136

const char *hookdir = HOOKDIR;

150

int hookdir_fd = -1;

151

uid_t uid = 65534;

152

gid_t gid = 65534;

153

137

154

138

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

155

139

typedef struct server{

156

140

const char *ip;

157

in_port_t port;

141

uint16_t port;

158

142

AvahiIfIndex if_index;

159

143

int af;

160

144

struct timespec last_seen;

164

148

165

149

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

166

150

typedef struct {

151

AvahiSimplePoll *simple_poll;

167

152

AvahiServer *server;

168

153

gnutls_certificate_credentials_t cred;

169

154

unsigned int dh_bits;

171

156

const char *priority;

172

157

gpgme_ctx_t ctx;

173

158

server *current_server;

174

char *interfaces;

175

size_t interfaces_size;

176

159

} mandos_context;

177

160

178

/* global so signal handler can reach it*/

179

AvahiSimplePoll *simple_poll;

161

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

162

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

163

.dh_bits = 1024, .priority = "SECURE256"

164

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

165

.current_server = NULL };

180

166

181

167

sig_atomic_t quit_now = 0;

182

168

int signal_received = 0;

183

169

184

170

/* Function to use when printing errors */

185

171

void perror_plus(const char *print_text){

186

int e = errno;

187

172

fprintf(stderr, "Mandos plugin %s: ",

188

173

program_invocation_short_name);

189

errno = e;

190

174

perror(print_text);

191

175

}

192

176

193

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

194

177

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

195

178

va_list ap;

196

179

va_start (ap, format);

197

180

198

181

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

199

182

program_invocation_short_name));

200

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

183

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

201

184

}

202

185

203

186

/*

205

188

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

206

189

* "buffer_length" is how much is already used.

207

190

*/

208

__attribute__((nonnull, warn_unused_result))

209

191

size_t incbuffer(char **buffer, size_t buffer_length,

210

192

size_t buffer_capacity){

211

193

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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;

194

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

195

if(buffer == NULL){

218

196

return 0;

219

197

}

220

*buffer = new_buf;

221

198

buffer_capacity += BUFFER_SIZE;

222

199

}

223

200

return buffer_capacity;

224

201

}

225

202

226

203

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

227

__attribute__((nonnull, warn_unused_result))

228

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

229

int af, server **current_server){

204

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

205

int af){

230

206

int ret;

231

207

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

232

208

if(new_server == NULL){

233

209

perror_plus("malloc");

234

return false;

210

return -1;

235

211

}

236

212

*new_server = (server){ .ip = strdup(ip),

237

213

.port = port,

239

215

.af = af };

240

216

if(new_server->ip == NULL){

241

217

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);

257

return false;

218

return -1;

258

219

}

259

220

/* Special case of first server */

260

if(*current_server == NULL){

221

if (mc.current_server == NULL){

261

222

new_server->next = new_server;

262

223

new_server->prev = new_server;

263

*current_server = new_server;

224

mc.current_server = new_server;

225

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

264

226

} else {

265

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

266

new_server->next = *current_server;

267

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

227

new_server->next = mc.current_server;

228

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

268

229

new_server->prev->next = new_server;

269

(*current_server)->prev = new_server;

270

}

271

return true;

230

mc.current_server->prev = new_server;

231

}

232

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

233

if(ret == -1){

234

perror_plus("clock_gettime");

235

return -1;

236

}

237

return 0;

272

238

}

273

239

274

240

/*

275

241

* Initialize GPGME.

276

242

*/

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){

243

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

244

const char *tempdir){

282

245

gpgme_error_t rc;

283

246

gpgme_engine_info_t engine_info;

284

247

248

285

249

/*

286

250

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

287

251

*/

288

bool import_key(const char * const filename){

252

bool import_key(const char *filename){

289

253

int ret;

290

254

int fd;

291

255

gpgme_data_t pgp_data;

303

267

return false;

304

268

}

305

269

306

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

270

rc = gpgme_op_import(mc.ctx, pgp_data);

307

271

if(rc != GPG_ERR_NO_ERROR){

308

272

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

309

273

gpgme_strsource(rc), gpgme_strerror(rc));

310

274

return false;

311

275

}

312

276

313

ret = close(fd);

277

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

314

278

if(ret == -1){

315

279

perror_plus("close");

316

280

}

353

317

}

354

318

355

319

/* Create new GPGME "context" */

356

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

320

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

357

321

if(rc != GPG_ERR_NO_ERROR){

358

322

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

359

323

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

372

336

* Decrypt OpenPGP data.

373

337

* Returns -1 on error

374

338

*/

375

__attribute__((nonnull, warn_unused_result))

376

339

static ssize_t pgp_packet_decrypt(const char *cryptotext,

377

340

size_t crypto_size,

378

char **plaintext,

379

mandos_context *mc){

341

char **plaintext){

380

342

gpgme_data_t dh_crypto, dh_plain;

381

343

gpgme_error_t rc;

382

344

ssize_t ret;

408

370

409

371

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

410

372

data buffer */

411

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

373

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

412

374

if(rc != GPG_ERR_NO_ERROR){

413

375

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

414

376

gpgme_strsource(rc), gpgme_strerror(rc));

415

377

plaintext_length = -1;

416

378

if(debug){

417

379

gpgme_decrypt_result_t result;

418

result = gpgme_op_decrypt_result(mc->ctx);

380

result = gpgme_op_decrypt_result(mc.ctx);

419

381

if(result == NULL){

420

382

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

421

383

} else {

498

460

return plaintext_length;

499

461

}

500

462

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){

510

const char *ret = gnutls_strerror(value);

511

return safe_string(ret);

463

static const char * safer_gnutls_strerror(int value){

464

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

465

-Wunreachable-code */

466

if(ret == NULL)

467

ret = "(unknown)";

468

return ret;

512

469

}

513

470

514

471

/* GnuTLS log function callback */

515

__attribute__((nonnull))

516

472

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

517

473

const char* string){

518

474

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

519

475

}

520

476

521

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

522

477

static int init_gnutls_global(const char *pubkeyfilename,

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

mandos_context *mc){

478

const char *seckeyfilename){

526

479

int ret;

527

unsigned int uret;

528

480

529

481

if(debug){

530

482

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

531

483

}

532

484

485

ret = gnutls_global_init();

486

if(ret != GNUTLS_E_SUCCESS){

487

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

488

safer_gnutls_strerror(ret));

489

return -1;

490

}

491

533

492

if(debug){

534

493

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

535

494

* - GnuTLS manual

539

498

}

540

499

541

500

/* OpenPGP credentials */

542

ret = gnutls_certificate_allocate_credentials(&mc->cred);

501

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

502

if(ret != GNUTLS_E_SUCCESS){

544

503

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

545

504

safer_gnutls_strerror(ret));

505

gnutls_global_deinit();

546

506

return -1;

547

507

}

548

508

554

514

}

555

515

556

516

ret = gnutls_certificate_set_openpgp_key_file

557

(mc->cred, pubkeyfilename, seckeyfilename,

517

(mc.cred, pubkeyfilename, seckeyfilename,

558

518

GNUTLS_OPENPGP_FMT_BASE64);

559

519

if(ret != GNUTLS_E_SUCCESS){

560

520

fprintf_plus(stderr,

566

526

}

567

527

568

528

/* GnuTLS server initialization */

569

ret = gnutls_dh_params_init(&mc->dh_params);

529

ret = gnutls_dh_params_init(&mc.dh_params);

570

530

if(ret != GNUTLS_E_SUCCESS){

571

531

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

572

532

" initialization: %s\n",

573

533

safer_gnutls_strerror(ret));

574

534

goto globalfail;

575

535

}

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

free(params.data);

630

} while(false);

631

}

632

if(dhparamsfilename == NULL){

633

if(mc->dh_bits == 0){

634

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

635

/* Try to read the private key file */

636

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

637

do {

638

int secfile = open(seckeyfilename, O_RDONLY);

639

if(secfile == -1){

640

perror_plus("open");

641

break;

642

}

643

size_t buffer_capacity = 0;

644

while(true){

645

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

646

(size_t)buffer.size,

647

(size_t)buffer_capacity);

648

if(buffer_capacity == 0){

649

perror_plus("incbuffer");

650

free(buffer.data);

651

buffer.data = NULL;

652

break;

653

}

654

ssize_t bytes_read = read(secfile,

655

buffer.data + buffer.size,

656

BUFFER_SIZE);

657

/* EOF */

658

if(bytes_read == 0){

659

break;

660

}

661

/* check bytes_read for failure */

662

if(bytes_read < 0){

663

perror_plus("read");

664

free(buffer.data);

665

buffer.data = NULL;

666

break;

667

}

668

buffer.size += (unsigned int)bytes_read;

669

}

670

close(secfile);

671

} while(false);

672

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

673

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

674

if(buffer.data != NULL){

675

{

676

gnutls_openpgp_privkey_t privkey = NULL;

677

ret = gnutls_openpgp_privkey_init(&privkey);

678

if(ret != GNUTLS_E_SUCCESS){

679

fprintf_plus(stderr, "Error initializing OpenPGP key"

680

" structure: %s",

681

safer_gnutls_strerror(ret));

682

free(buffer.data);

683

buffer.data = NULL;

684

} else {

685

ret = gnutls_openpgp_privkey_import

686

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

687

if(ret != GNUTLS_E_SUCCESS){

688

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

689

safer_gnutls_strerror(ret));

690

privkey = NULL;

691

}

692

free(buffer.data);

693

buffer.data = NULL;

694

if(privkey != NULL){

695

/* Use private key to suggest an appropriate

696

sec_param */

697

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

698

gnutls_openpgp_privkey_deinit(privkey);

699

if(debug){

700

fprintf_plus(stderr, "This OpenPGP key implies using"

701

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

702

safe_string(gnutls_sec_param_get_name

703

(sec_param)));

704

}

705

}

706

}

707

}

708

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

709

/* Err on the side of caution */

710

sec_param = GNUTLS_SEC_PARAM_ULTRA;

711

if(debug){

712

fprintf_plus(stderr, "Falling back to security parameter"

713

" \"%s\"\n",

714

safe_string(gnutls_sec_param_get_name

715

(sec_param)));

716

}

717

}

718

}

719

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

720

if(uret != 0){

721

mc->dh_bits = uret;

722

if(debug){

723

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

724

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

725

safe_string(gnutls_sec_param_get_name

726

(sec_param)),

727

mc->dh_bits);

728

}

729

} else {

730

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

731

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

732

safe_string(gnutls_sec_param_get_name

733

(sec_param)),

734

safer_gnutls_strerror(ret));

735

goto globalfail;

736

}

737

} else if(debug){

738

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

739

mc->dh_bits);

740

}

741

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

742

if(ret != GNUTLS_E_SUCCESS){

743

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

744

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

745

safer_gnutls_strerror(ret));

746

goto globalfail;

747

}

748

}

749

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

536

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

537

if(ret != GNUTLS_E_SUCCESS){

538

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

539

safer_gnutls_strerror(ret));

540

goto globalfail;

541

}

542

543

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

750

544

751

545

return 0;

752

546

753

547

globalfail:

754

548

755

gnutls_certificate_free_credentials(mc->cred);

756

gnutls_dh_params_deinit(mc->dh_params);

549

gnutls_certificate_free_credentials(mc.cred);

550

gnutls_global_deinit();

551

gnutls_dh_params_deinit(mc.dh_params);

757

552

return -1;

758

553

}

759

554

760

__attribute__((nonnull, warn_unused_result))

761

static int init_gnutls_session(gnutls_session_t *session,

762

mandos_context *mc){

555

static int init_gnutls_session(gnutls_session_t *session){

763

556

int ret;

764

557

/* GnuTLS session creation */

765

558

do {

777

570

{

778

571

const char *err;

779

572

do {

780

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

573

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

781

574

if(quit_now){

782

575

gnutls_deinit(*session);

783

576

return -1;

794

587

795

588

do {

796

589

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

797

mc->cred);

590

mc.cred);

798

591

if(quit_now){

799

592

gnutls_deinit(*session);

800

593

return -1;

810

603

/* ignore client certificate if any. */

811

604

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

812

605

606

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

607

813

608

return 0;

814

609

}

815

610

817

612

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

818

613

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

819

614

820

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

821

__attribute__((warn_unused_result))

822

int raise_privileges(void){

823

int old_errno = errno;

824

int ret = 0;

825

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

826

ret = errno;

827

}

828

errno = old_errno;

829

return ret;

830

}

831

832

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

833

__attribute__((warn_unused_result))

834

int raise_privileges_permanently(void){

835

int old_errno = errno;

836

int ret = raise_privileges();

837

if(ret != 0){

838

errno = old_errno;

839

return ret;

840

}

841

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

842

ret = errno;

843

}

844

errno = old_errno;

845

return ret;

846

}

847

848

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

849

__attribute__((warn_unused_result))

850

int lower_privileges(void){

851

int old_errno = errno;

852

int ret = 0;

853

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

854

ret = errno;

855

}

856

errno = old_errno;

857

return ret;

858

}

859

860

/* Lower privileges permanently */

861

__attribute__((warn_unused_result))

862

int lower_privileges_permanently(void){

863

int old_errno = errno;

864

int ret = 0;

865

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

866

ret = errno;

867

}

868

errno = old_errno;

869

return ret;

870

}

871

872

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

873

__attribute__((nonnull, warn_unused_result))

874

static bool add_delete_local_route(const bool add,

875

const char *address,

876

AvahiIfIndex if_index){

877

int ret;

878

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

879

char add_arg[] = "add";

880

char delete_arg[] = "delete";

881

char debug_flag[] = "--debug";

882

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

883

if(pluginhelperdir == NULL){

884

if(debug){

885

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

886

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

887

}

888

return false;

889

}

890

891

char interface[IF_NAMESIZE];

892

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

893

perror_plus("if_indextoname");

894

return false;

895

}

896

897

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

898

if(devnull == -1){

899

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

900

return false;

901

}

902

pid_t pid = fork();

903

if(pid == 0){

904

/* Child */

905

/* Raise privileges */

906

errno = raise_privileges_permanently();

907

if(errno != 0){

908

perror_plus("Failed to raise privileges");

909

/* _exit(EX_NOPERM); */

910

} else {

911

/* Set group */

912

errno = 0;

913

ret = setgid(0);

914

if(ret == -1){

915

perror_plus("setgid");

916

_exit(EX_NOPERM);

917

}

918

/* Reset supplementary groups */

919

errno = 0;

920

ret = setgroups(0, NULL);

921

if(ret == -1){

922

perror_plus("setgroups");

923

_exit(EX_NOPERM);

924

}

925

}

926

ret = dup2(devnull, STDIN_FILENO);

927

if(ret == -1){

928

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

929

_exit(EX_OSERR);

930

}

931

ret = close(devnull);

932

if(ret == -1){

933

perror_plus("close");

934

_exit(EX_OSERR);

935

}

936

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

937

if(ret == -1){

938

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

939

_exit(EX_OSERR);

940

}

941

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

942

O_RDONLY

943

| O_DIRECTORY

944

| O_PATH

945

| O_CLOEXEC));

946

if(helperdir_fd == -1){

947

perror_plus("open");

948

_exit(EX_UNAVAILABLE);

949

}

950

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

951

helper, O_RDONLY));

952

if(helper_fd == -1){

953

perror_plus("openat");

954

close(helperdir_fd);

955

_exit(EX_UNAVAILABLE);

956

}

957

close(helperdir_fd);

958

#ifdef __GNUC__

959

#pragma GCC diagnostic push

960

#pragma GCC diagnostic ignored "-Wcast-qual"

961

#endif

962

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

963

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

964

interface, debug ? debug_flag : NULL, NULL },

965

environ) == -1){

966

#ifdef __GNUC__

967

#pragma GCC diagnostic pop

968

#endif

969

perror_plus("fexecve");

970

_exit(EXIT_FAILURE);

971

}

972

}

973

if(pid == -1){

974

perror_plus("fork");

975

return false;

976

}

977

int status;

978

pid_t pret = -1;

979

errno = 0;

980

do {

981

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

982

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

983

int errno_raising = 0;

984

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

985

errno_raising = errno;

986

perror_plus("Failed to raise privileges in order to"

987

" kill helper program");

988

}

989

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

990

perror_plus("kill");

991

}

992

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

993

perror_plus("Failed to lower privileges after killing"

994

" helper program");

995

}

996

return false;

997

}

998

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

999

if(pret == -1){

1000

perror_plus("waitpid");

1001

return false;

1002

}

1003

if(WIFEXITED(status)){

1004

if(WEXITSTATUS(status) != 0){

1005

fprintf_plus(stderr, "Error: iprouteadddel exited"

1006

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

1007

return false;

1008

}

1009

return true;

1010

}

1011

if(WIFSIGNALED(status)){

1012

fprintf_plus(stderr, "Error: iprouteadddel died by"

1013

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

1014

return false;

1015

}

1016

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

1017

return false;

1018

}

1019

1020

__attribute__((nonnull, warn_unused_result))

1021

static bool add_local_route(const char *address,

1022

AvahiIfIndex if_index){

1023

if(debug){

1024

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

1025

}

1026

return add_delete_local_route(true, address, if_index);

1027

}

1028

1029

__attribute__((nonnull, warn_unused_result))

1030

static bool delete_local_route(const char *address,

1031

AvahiIfIndex if_index){

1032

if(debug){

1033

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

1034

}

1035

return add_delete_local_route(false, address, if_index);

1036

}

1037

1038

615

/* Called when a Mandos server is found */

1039

__attribute__((nonnull, warn_unused_result))

1040

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

616

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

1041

617

AvahiIfIndex if_index,

1042

int af, mandos_context *mc){

618

int af){

1043

619

int ret, tcp_sd = -1;

1044

620

ssize_t sret;

1045

struct sockaddr_storage to;

621

union {

622

struct sockaddr_in in;

623

struct sockaddr_in6 in6;

624

} to;

1046

625

char *buffer = NULL;

1047

626

char *decrypted_buffer = NULL;

1048

627

size_t buffer_length = 0;

1051

630

int retval = -1;

1052

631

gnutls_session_t session;

1053

632

int pf; /* Protocol family */

1054

bool route_added = false;

1055

633

1056

634

errno = 0;

1057

635

1073

651

return -1;

1074

652

}

1075

653

1076

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

1077

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

1078

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

1079

bool match = false;

1080

{

1081

char *interface = NULL;

1082

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

1083

mc->interfaces_size,

1084

interface))){

1085

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

1086

match = true;

1087

break;

1088

}

1089

}

1090

}

1091

if(not match){

1092

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

1093

connect to the server */

1094

if(debug){

1095

char interface[IF_NAMESIZE];

1096

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

1097

perror_plus("if_indextoname");

1098

} else {

1099

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

1100

" \"%s\"\n",

1101

if_indextoname((unsigned int)if_index,

1102

interface));

1103

}

1104

}

1105

return -1;

1106

}

1107

}

1108

1109

ret = init_gnutls_session(&session, mc);

654

ret = init_gnutls_session(&session);

1110

655

if(ret != 0){

1111

656

return -1;

1112

657

}

1113

658

1114

659

if(debug){

1115

660

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

1116

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

661

PRIu16 "\n", ip, port);

1117

662

}

1118

663

1119

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

664

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

665

if(tcp_sd < 0){

1121

666

int e = errno;

1122

667

perror_plus("socket");

1129

674

goto mandos_end;

1130

675

}

1131

676

677

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

1132

678

if(af == AF_INET6){

1133

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

1134

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

1135

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

679

to.in6.sin6_family = (sa_family_t)af;

680

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

1136

681

} else { /* IPv4 */

1137

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

1138

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

1139

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

682

to.in.sin_family = (sa_family_t)af;

683

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

1140

684

}

1141

685

if(ret < 0 ){

1142

686

int e = errno;

1151

695

goto mandos_end;

1152

696

}

1153

697

if(af == AF_INET6){

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

698

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

699

-Wconversion and

700

-Wunreachable-code */

701

702

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

703

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

704

-Wunreachable-code*/

1157

705

if(if_index == AVAHI_IF_UNSPEC){

1158

706

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

1159

707

" incomplete without a network interface\n");

1161

709

goto mandos_end;

1162

710

}

1163

711

/* Set the network interface number as scope */

1164

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

712

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

713

}

1166

714

} else {

1167

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

715

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

716

-Wconversion and

717

-Wunreachable-code */

1168

718

}

1169

719

1170

720

if(quit_now){

1178

728

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

1179

729

perror_plus("if_indextoname");

1180

730

} else {

1181

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

1182

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

731

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

732

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

1183

733

}

1184

734

} else {

1185

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

1186

ip, (uintmax_t)port);

735

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

736

ip, port);

1187

737

}

1188

738

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1189

739

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1190

if(af == AF_INET6){

1191

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

1192

sizeof(struct sockaddr_in6),

1193

addrstr, sizeof(addrstr), NULL, 0,

1194

NI_NUMERICHOST);

1195

} else {

1196

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

1197

sizeof(struct sockaddr_in),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

}

1201

if(ret == EAI_SYSTEM){

1202

perror_plus("getnameinfo");

1203

} else if(ret != 0) {

1204

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

1205

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

1206

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

1207

}

1208

}

1209

1210

if(quit_now){

1211

errno = EINTR;

1212

goto mandos_end;

1213

}

1214

1215

while(true){

1216

if(af == AF_INET6){

1217

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

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

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

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

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

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

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

1234

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

1235

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

1236

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

1237

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

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

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

1241

1242

Avahi bug reference:

1243

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

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

740

const char *pcret;

741

if(af == AF_INET6){

742

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

743

sizeof(addrstr));

744

} else {

745

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

746

sizeof(addrstr));

747

}

748

if(pcret == NULL){

749

perror_plus("inet_ntop");

750

} else {

751

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

752

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

753

}

754

}

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

760

}

761

762

if(af == AF_INET6){

763

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

764

} else {

765

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

766

}

767

if(ret < 0){

768

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

769

int e = errno;

770

perror_plus("connect");

771

errno = e;

772

}

773

goto mandos_end;

774

}

775

776

if(quit_now){

777

errno = EINTR;

778

goto mandos_end;

1270

779

}

1271

780

1272

781

const char *out = mandos_protocol_version;

1308

817

goto mandos_end;

1309

818

}

1310

819

1311

/* This casting via intptr_t is to eliminate warning about casting

1312

an int to a pointer type. This is exactly how the GnuTLS Guile

1313

function "set-session-transport-fd!" does it. */

1314

gnutls_transport_set_ptr(session,

1315

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

820

/* Spurious warning from -Wint-to-pointer-cast */

821

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1316

822

1317

823

if(quit_now){

1318

824

errno = EINTR;

1423

929

if(buffer_length > 0){

1424

930

ssize_t decrypted_buffer_size;

1425

931

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1426

&decrypted_buffer, mc);

932

&decrypted_buffer);

1427

933

if(decrypted_buffer_size >= 0){

1428

934

1429

clearerr(stdout);

1430

935

written = 0;

1431

936

while(written < (size_t) decrypted_buffer_size){

1432

937

if(quit_now){

1448

953

}

1449

954

written += (size_t)ret;

1450

955

}

1451

ret = fflush(stdout);

1452

if(ret != 0){

1453

int e = errno;

1454

if(debug){

1455

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

1456

strerror(errno));

1457

}

1458

errno = e;

1459

goto mandos_end;

1460

}

1461

956

retval = 0;

1462

957

}

1463

958

}

1466

961

1467

962

mandos_end:

1468

963

{

1469

if(route_added){

1470

if(not delete_local_route(ip, if_index)){

1471

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

1472

" interface %d", ip, if_index);

1473

}

1474

}

1475

964

int e = errno;

1476

965

free(decrypted_buffer);

1477

966

free(buffer);

1478

967

if(tcp_sd >= 0){

1479

ret = close(tcp_sd);

968

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

1480

969

}

1481

970

if(ret == -1){

1482

971

if(e == 0){

1507

996

AVAHI_GCC_UNUSED AvahiStringList *txt,

1508

997

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1509

998

flags,

1510

void *mc){

1511

if(r == NULL){

1512

return;

1513

}

999

AVAHI_GCC_UNUSED void* userdata){

1000

assert(r);

1514

1001

1515

1002

/* Called whenever a service has been resolved successfully or

1516

1003

timed out */

1517

1004

1518

1005

if(quit_now){

1519

avahi_s_service_resolver_free(r);

1520

1006

return;

1521

1007

}

1522

1008

1526

1012

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

1527

1013

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

1528

1014

domain,

1529

avahi_strerror(avahi_server_errno

1530

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

1015

avahi_strerror(avahi_server_errno(mc.server)));

1531

1016

break;

1532

1017

1533

1018

case AVAHI_RESOLVER_FOUND:

1539

1024

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

1540

1025

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

1541

1026

}

1542

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

1543

interface,

1544

avahi_proto_to_af(proto),

1545

mc);

1027

int ret = start_mandos_communication(ip, port, interface,

1028

avahi_proto_to_af(proto));

1546

1029

if(ret == 0){

1547

avahi_simple_poll_quit(simple_poll);

1030

avahi_simple_poll_quit(mc.simple_poll);

1548

1031

} else {

1549

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

1550

avahi_proto_to_af(proto),

1551

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

1552

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

1553

" list\n", name);

1554

}

1032

ret = add_server(ip, port, interface,

1033

avahi_proto_to_af(proto));

1555

1034

}

1556

1035

}

1557

1036

}

1567

1046

const char *domain,

1568

1047

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1569

1048

flags,

1570

void *mc){

1571

if(b == NULL){

1572

return;

1573

}

1049

AVAHI_GCC_UNUSED void* userdata){

1050

assert(b);

1574

1051

1575

1052

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

1576

1053

is removed from the LAN */

1584

1061

case AVAHI_BROWSER_FAILURE:

1585

1062

1586

1063

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

1587

avahi_strerror(avahi_server_errno

1588

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

1589

avahi_simple_poll_quit(simple_poll);

1064

avahi_strerror(avahi_server_errno(mc.server)));

1065

avahi_simple_poll_quit(mc.simple_poll);

1590

1066

return;

1591

1067

1592

1068

case AVAHI_BROWSER_NEW:

1595

1071

the callback function is called the Avahi server will free the

1596

1072

resolver for us. */

1597

1073

1598

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

1599

interface, protocol, name, type,

1600

domain, protocol, 0,

1601

resolve_callback, mc) == NULL)

1074

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

1075

name, type, domain, protocol, 0,

1076

resolve_callback, NULL) == NULL)

1602

1077

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

1603

1078

" %s\n", name,

1604

avahi_strerror(avahi_server_errno

1605

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

1079

avahi_strerror(avahi_server_errno(mc.server)));

1606

1080

break;

1607

1081

1608

1082

case AVAHI_BROWSER_REMOVE:

1627

1101

signal_received = sig;

1628

1102

int old_errno = errno;

1629

1103

/* set main loop to exit */

1630

if(simple_poll != NULL){

1631

avahi_simple_poll_quit(simple_poll);

1104

if(mc.simple_poll != NULL){

1105

avahi_simple_poll_quit(mc.simple_poll);

1632

1106

}

1633

1107

errno = old_errno;

1634

1108

}

1635

1109

1636

__attribute__((nonnull, warn_unused_result))

1637

1110

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

1638

1111

int ret;

1639

int old_errno;

1640

1112

1641

1113

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

1642

1114

if(s < 0){

1643

old_errno = errno;

1644

1115

perror_plus("socket");

1645

errno = old_errno;

1646

1116

return false;

1647

1117

}

1648

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

1649

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

1118

strcpy(ifr->ifr_name, ifname);

1650

1119

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1651

1120

if(ret == -1){

1652

1121

if(debug){

1653

old_errno = errno;

1654

1122

perror_plus("ioctl SIOCGIFFLAGS");

1655

errno = old_errno;

1656

1123

}

1657

1124

return false;

1658

1125

}

1659

1126

return true;

1660

1127

}

1661

1128

1662

__attribute__((nonnull, warn_unused_result))

1663

1129

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

1664

1130

1665

1131

/* Reject the loopback device */

1707

1173

* corresponds to an acceptable network device.

1708

1174

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

1709

1175

*/

1710

__attribute__((nonnull, warn_unused_result))

1711

1176

int good_interface(const struct dirent *if_entry){

1712

1177

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

1713

1178

return 0;

1729

1194

}

1730

1195

1731

1196

/*

1732

* This function determines if a network interface is up.

1733

*/

1734

__attribute__((nonnull, warn_unused_result))

1735

bool interface_is_up(const char *interface){

1736

struct ifreq ifr;

1737

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

1738

if(debug){

1739

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

1740

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

1741

}

1742

return false;

1743

}

1744

1745

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

1746

}

1747

1748

/*

1749

* This function determines if a network interface is running

1750

*/

1751

__attribute__((nonnull, warn_unused_result))

1752

bool interface_is_running(const char *interface){

1753

struct ifreq ifr;

1754

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

1755

if(debug){

1756

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

1757

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

1758

}

1759

return false;

1760

}

1761

1762

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

1763

}

1764

1765

__attribute__((nonnull, pure, warn_unused_result))

1197

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

1198

* corresponds to an acceptable network device which is up.

1199

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

1200

*/

1201

int up_interface(const struct dirent *if_entry){

1202

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

1203

return 0;

1204

}

1205

1206

struct ifreq ifr;

1207

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

1208

if(debug){

1209

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

1210

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

1211

}

1212

return 0;

1213

}

1214

1215

/* Reject down interfaces */

1216

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

1217

if(debug){

1218

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

1219

if_entry->d_name);

1220

}

1221

return 0;

1222

}

1223

1224

/* Reject non-running interfaces */

1225

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

1226

if(debug){

1227

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

1228

if_entry->d_name);

1229

}

1230

return 0;

1231

}

1232

1233

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

1234

return 0;

1235

}

1236

return 1;

1237

}

1238

1766

1239

int notdotentries(const struct dirent *direntry){

1767

1240

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

1768

1241

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

1775

1248

}

1776

1249

1777

1250

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

1778

__attribute__((nonnull, warn_unused_result))

1779

1251

int runnable_hook(const struct dirent *direntry){

1780

1252

int ret;

1781

1253

size_t sret;

1789

1261

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

1790

1262

"abcdefghijklmnopqrstuvwxyz"

1791

1263

"0123456789"

1792

"_.-");

1264

"_-");

1793

1265

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

1794

1266

/* Contains non-allowed characters */

1795

1267

if(debug){

1799

1271

return 0;

1800

1272

}

1801

1273

1802

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

1274

char *fullname = NULL;

1275

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

1276

if(ret < 0){

1277

perror_plus("asprintf");

1278

return 0;

1279

}

1280

1281

ret = stat(fullname, &st);

1803

1282

if(ret == -1){

1804

1283

if(debug){

1805

1284

perror_plus("Could not stat hook");

1829

1308

return 1;

1830

1309

}

1831

1310

1832

__attribute__((nonnull, warn_unused_result))

1833

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1834

mandos_context *mc){

1311

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1835

1312

int ret;

1836

1313

struct timespec now;

1837

1314

struct timespec waited_time;

1838

1315

intmax_t block_time;

1839

1316

1840

1317

while(true){

1841

if(mc->current_server == NULL){

1842

if(debug){

1318

if(mc.current_server == NULL){

1319

if (debug){

1843

1320

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

1844

1321

" No timeout!\n");

1845

1322

}

1846

1323

ret = avahi_simple_poll_iterate(s, -1);

1847

1324

} else {

1848

if(debug){

1325

if (debug){

1849

1326

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

1850

1327

" it, or wait\n");

1851

1328

}

1858

1335

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

1859

1336

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

1860

1337

waited_time.tv_sec = (now.tv_sec

1861

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

1338

- mc.current_server->last_seen.tv_sec);

1862

1339

waited_time.tv_nsec = (now.tv_nsec

1863

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

1340

- mc.current_server->last_seen.tv_nsec);

1864

1341

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

1865

1342

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

1866

1343

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

1868

1345

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

1869

1346

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

1870

1347

1871

if(debug){

1348

if (debug){

1872

1349

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

1873

1350

block_time);

1874

1351

}

1875

1352

1876

1353

if(block_time <= 0){

1877

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

1878

mc->current_server->port,

1879

mc->current_server->if_index,

1880

mc->current_server->af, mc);

1354

ret = start_mandos_communication(mc.current_server->ip,

1355

mc.current_server->port,

1356

mc.current_server->if_index,

1357

mc.current_server->af);

1881

1358

if(ret == 0){

1882

avahi_simple_poll_quit(s);

1359

avahi_simple_poll_quit(mc.simple_poll);

1883

1360

return 0;

1884

1361

}

1885

1362

ret = clock_gettime(CLOCK_MONOTONIC,

1886

&mc->current_server->last_seen);

1363

&mc.current_server->last_seen);

1887

1364

if(ret == -1){

1888

1365

perror_plus("clock_gettime");

1889

1366

return -1;

1890

1367

}

1891

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

1368

mc.current_server = mc.current_server->next;

1892

1369

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

1893

1370

servers, but don't block */

1894

1371

}

1896

1373

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

1897

1374

}

1898

1375

if(ret != 0){

1899

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

1376

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

1900

1377

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

1901

1378

}

1902

1379

}

1903

1380

}

1904

1381

}

1905

1382

1906

__attribute__((nonnull))

1907

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

1383

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

1908

1384

const float delay){

1909

struct dirent **direntries = NULL;

1910

if(hookdir_fd == -1){

1911

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1912

| O_CLOEXEC);

1913

if(hookdir_fd == -1){

1914

if(errno == ENOENT){

1915

if(debug){

1916

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

1917

" found\n", hookdir);

1918

}

1919

} else {

1920

perror_plus("open");

1921

}

1922

return;

1923

}

1924

}

1925

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

1926

runnable_hook, alphasort);

1385

struct dirent **direntries;

1386

struct dirent *direntry;

1387

int ret;

1388

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

1389

alphasort);

1927

1390

if(numhooks == -1){

1928

1391

perror_plus("scandir");

1929

return;

1930

}

1931

struct dirent *direntry;

1932

int ret;

1933

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

1934

if(devnull == -1){

1935

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

1936

return;

1937

}

1938

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

1939

direntry = direntries[i];

1940

if(debug){

1941

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

1942

direntry->d_name);

1943

}

1944

pid_t hook_pid = fork();

1945

if(hook_pid == 0){

1946

/* Child */

1947

/* Raise privileges */

1948

errno = raise_privileges_permanently();

1949

if(errno != 0){

1950

perror_plus("Failed to raise privileges");

1951

_exit(EX_NOPERM);

1952

}

1953

/* Set group */

1954

errno = 0;

1955

ret = setgid(0);

1956

if(ret == -1){

1957

perror_plus("setgid");

1958

_exit(EX_NOPERM);

1959

}

1960

/* Reset supplementary groups */

1961

errno = 0;

1962

ret = setgroups(0, NULL);

1963

if(ret == -1){

1964

perror_plus("setgroups");

1965

_exit(EX_NOPERM);

1966

}

1967

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

1968

if(ret == -1){

1969

perror_plus("setenv");

1970

_exit(EX_OSERR);

1971

}

1972

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

1973

if(ret == -1){

1974

perror_plus("setenv");

1975

_exit(EX_OSERR);

1976

}

1977

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

1978

if(ret == -1){

1979

perror_plus("setenv");

1980

_exit(EX_OSERR);

1981

}

1982

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

1983

if(ret == -1){

1984

perror_plus("setenv");

1985

_exit(EX_OSERR);

1986

}

1987

char *delaystring;

1988

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

1989

if(ret == -1){

1392

} else {

1393

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

1394

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

1395

direntry = direntries[i];

1396

char *fullname = NULL;

1397

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

1398

if(ret < 0){

1990

1399

perror_plus("asprintf");

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1400

continue;

1401

}

1402

if(debug){

1403

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

1404

direntry->d_name);

1405

}

1406

pid_t hook_pid = fork();

1407

if(hook_pid == 0){

1408

/* Child */

1409

dup2(devnull, STDIN_FILENO);

1410

close(devnull);

1411

dup2(STDERR_FILENO, STDOUT_FILENO);

1412

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

1413

if(ret == -1){

1414

perror_plus("setenv");

1415

return false;

1416

}

1417

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

1418

if(ret == -1){

1419

perror_plus("setenv");

1420

return false;

1421

}

1422

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

1423

if(ret == -1){

1424

perror_plus("setenv");

1425

return false;

1426

}

1427

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

1428

if(ret == -1){

1429

perror_plus("setenv");

1430

return false;

1431

}

1432

char *delaystring;

1433

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

1434

if(ret == -1){

1435

perror_plus("asprintf");

1436

return false;

1437

}

1438

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

1439

if(ret == -1){

1440

free(delaystring);

1441

perror_plus("setenv");

1442

return false;

1443

}

1995

1444

free(delaystring);

1996

perror_plus("setenv");

1997

_exit(EX_OSERR);

1998

}

1999

free(delaystring);

2000

if(connect_to != NULL){

2001

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

2002

if(ret == -1){

2003

perror_plus("setenv");

2004

_exit(EX_OSERR);

2005

}

2006

}

2007

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

2008

direntry->d_name,

2009

O_RDONLY));

2010

if(hook_fd == -1){

2011

perror_plus("openat");

2012

_exit(EXIT_FAILURE);

2013

}

2014

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

2015

perror_plus("close");

2016

_exit(EXIT_FAILURE);

2017

}

2018

ret = dup2(devnull, STDIN_FILENO);

2019

if(ret == -1){

2020

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

2021

_exit(EX_OSERR);

2022

}

2023

ret = close(devnull);

2024

if(ret == -1){

2025

perror_plus("close");

2026

_exit(EX_OSERR);

2027

}

2028

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2029

if(ret == -1){

2030

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

2031

_exit(EX_OSERR);

2032

}

2033

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

2034

environ) == -1){

2035

perror_plus("fexecve");

2036

_exit(EXIT_FAILURE);

2037

}

2038

} else {

2039

if(hook_pid == -1){

2040

perror_plus("fork");

2041

free(direntry);

2042

continue;

2043

}

2044

int status;

2045

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

2046

perror_plus("waitpid");

2047

free(direntry);

2048

continue;

2049

}

2050

if(WIFEXITED(status)){

2051

if(WEXITSTATUS(status) != 0){

2052

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

2053

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

2054

WEXITSTATUS(status));

2055

free(direntry);

2056

continue;

2057

}

2058

} else if(WIFSIGNALED(status)){

2059

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

2060

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

2061

WTERMSIG(status));

2062

free(direntry);

2063

continue;

2064

} else {

2065

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

2066

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

2067

free(direntry);

2068

continue;

2069

}

2070

}

2071

if(debug){

2072

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

2073

direntry->d_name);

2074

}

2075

free(direntry);

2076

}

2077

free(direntries);

2078

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

2079

perror_plus("close");

2080

} else {

2081

hookdir_fd = -1;

2082

}

2083

close(devnull);

2084

}

2085

2086

__attribute__((nonnull, warn_unused_result))

2087

int bring_up_interface(const char *const interface,

2088

const float delay){

2089

int old_errno = errno;

2090

int ret;

2091

struct ifreq network;

2092

unsigned int if_index = if_nametoindex(interface);

2093

if(if_index == 0){

2094

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

2095

errno = old_errno;

2096

return ENXIO;

2097

}

2098

2099

if(quit_now){

2100

errno = old_errno;

2101

return EINTR;

2102

}

2103

2104

if(not interface_is_up(interface)){

2105

int ret_errno = 0;

2106

int ioctl_errno = 0;

2107

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

2108

ret_errno = errno;

2109

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

2110

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

2111

errno = old_errno;

2112

return ret_errno;

2113

}

2114

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

2115

2116

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

2117

if(sd == -1){

2118

ret_errno = errno;

2119

perror_plus("socket");

2120

errno = old_errno;

2121

return ret_errno;

2122

}

2123

2124

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

2129

errno = old_errno;

2130

return EINTR;

2131

}

2132

2133

if(debug){

2134

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

2135

interface);

2136

}

2137

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

2144

2145

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

2157

}

2158

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

2161

#ifdef __linux__

2162

if(restore_loglevel){

2163

ret_linux = klogctl(7, NULL, 0);

2164

if(ret_linux == -1){

2165

perror_plus("klogctl");

2166

}

2167

}

2168

#endif /* __linux__ */

2169

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

2179

2180

/* Close the socket */

2181

ret = close(sd);

2182

if(ret == -1){

2183

perror_plus("close");

2184

}

2185

2186

if(ret_setflags == -1){

2187

errno = ioctl_errno;

2188

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

errno = old_errno;

2190

return ioctl_errno;

2191

}

2192

} else if(debug){

2193

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

2194

interface);

2195

}

2196

2197

/* Sleep checking until interface is running.

2198

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

2199

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

2200

if(interface_is_running(interface)){

2201

break;

2202

}

2203

struct timespec sleeptime = { .tv_nsec = 250000000 };

2204

ret = nanosleep(&sleeptime, NULL);

2205

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

2206

perror_plus("nanosleep");

2207

}

2208

}

2209

2210

errno = old_errno;

2211

return 0;

2212

}

2213

2214

__attribute__((nonnull, warn_unused_result))

2215

int take_down_interface(const char *const interface){

2216

int old_errno = errno;

2217

struct ifreq network;

2218

unsigned int if_index = if_nametoindex(interface);

2219

if(if_index == 0){

2220

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

2221

errno = old_errno;

2222

return ENXIO;

2223

}

2224

if(interface_is_up(interface)){

2225

int ret_errno = 0;

2226

int ioctl_errno = 0;

2227

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

2228

ret_errno = errno;

2229

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

2230

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

2231

errno = old_errno;

2232

return ret_errno;

2233

}

2234

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

2235

2236

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

2237

if(sd == -1){

2238

ret_errno = errno;

2239

perror_plus("socket");

2240

errno = old_errno;

2241

return ret_errno;

2242

}

2243

2244

if(debug){

2245

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

2246

interface);

2247

}

2248

2249

/* Raise privileges */

2250

ret_errno = raise_privileges();

2251

if(ret_errno != 0){

2252

errno = ret_errno;

2253

perror_plus("Failed to raise privileges");

2254

}

2255

2256

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

2257

ioctl_errno = errno;

2258

2259

/* If raise_privileges() succeeded above */

2260

if(ret_errno == 0){

2261

/* Lower privileges */

2262

ret_errno = lower_privileges();

2263

if(ret_errno != 0){

2264

errno = ret_errno;

2265

perror_plus("Failed to lower privileges");

2266

}

2267

}

2268

2269

/* Close the socket */

2270

int ret = close(sd);

2271

if(ret == -1){

2272

perror_plus("close");

2273

}

2274

2275

if(ret_setflags == -1){

2276

errno = ioctl_errno;

2277

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2278

errno = old_errno;

2279

return ioctl_errno;

2280

}

2281

} else if(debug){

2282

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

2283

interface);

2284

}

2285

2286

errno = old_errno;

2287

return 0;

1445

ret = execl(fullname, direntry->d_name, mode, NULL);

1446

perror_plus("execl");

1447

} else {

1448

int status;

1449

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

1450

perror_plus("waitpid");

1451

free(fullname);

1452

continue;

1453

}

1454

if(WIFEXITED(status)){

1455

if(WEXITSTATUS(status) != 0){

1456

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

1457

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

1458

WEXITSTATUS(status));

1459

free(fullname);

1460

continue;

1461

}

1462

} else if(WIFSIGNALED(status)){

1463

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

1464

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

1465

WTERMSIG(status));

1466

free(fullname);

1467

continue;

1468

} else {

1469

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

1470

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

1471

free(fullname);

1472

continue;

1473

}

1474

}

1475

free(fullname);

1476

if(debug){

1477

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

1478

direntry->d_name);

1479

}

1480

}

1481

close(devnull);

1482

}

1483

return true;

2288

1484

}

2289

1485

2290

1486

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

2291

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

2292

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

2293

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

2294

.current_server = NULL, .interfaces = NULL,

2295

.interfaces_size = 0 };

2296

1487

AvahiSServiceBrowser *sb = NULL;

2297

error_t ret_errno;

1488

int error;

2298

1489

int ret;

2299

1490

intmax_t tmpmax;

2300

1491

char *tmp;

2301

1492

int exitcode = EXIT_SUCCESS;

2302

char *interfaces_to_take_down = NULL;

2303

size_t interfaces_to_take_down_size = 0;

2304

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

2305

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

2306

char *tempdir = NULL;

1493

const char *interface = "";

1494

struct ifreq network;

1495

int sd = -1;

1496

bool take_down_interface = false;

1497

uid_t uid;

1498

gid_t gid;

1499

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

1500

bool tempdir_created = false;

2307

1501

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2308

1502

const char *seckey = PATHDIR "/" SECKEY;

2309

1503

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

2311

char *interfaces_hooks = NULL;

2312

1504

2313

1505

bool gnutls_initialized = false;

2314

1506

bool gpgme_initialized = false;

2366

1558

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

2367

1559

" Diffie-Hellman key exchange",

2368

1560

.group = 2 },

2369

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

2370

.arg = "FILE",

2371

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

2372

" for the Diffie-Hellman key exchange",

2373

.group = 2 },

2374

1561

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

2375

1562

.arg = "STRING",

2376

1563

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

2381

1568

.group = 2 },

2382

1569

{ .name = "retry", .key = 132,

2383

1570

.arg = "SECONDS",

2384

.doc = "Retry interval used when denied by the Mandos server",

1571

.doc = "Retry interval used when denied by the mandos server",

2385

1572

.group = 2 },

2386

1573

{ .name = "network-hook-dir", .key = 133,

2387

1574

.arg = "DIR",

2410

1597

connect_to = arg;

2411

1598

break;

2412

1599

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

2413

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

2414

arg, (int)',');

2415

if(ret_errno != 0){

2416

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

2417

}

1600

interface = arg;

2418

1601

break;

2419

1602

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

2420

1603

seckey = arg;

2431

1614

}

2432

1615

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

2433

1616

break;

2434

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

2435

dh_params_file = arg;

2436

break;

2437

1617

case 130: /* --priority */

2438

1618

mc.priority = arg;

2439

1619

break;

2466

1646

argp_state_help(state, state->out_stream,

2467

1647

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2468

1648

case 'V': /* --version */

1649

fprintf_plus(state->out_stream,

1650

"Mandos plugin mandos-client: ");

2469

1651

fprintf_plus(state->out_stream, "%s\n", argp_program_version);

2470

1652

exit(argp_err_exit_status);

2471

1653

break;

2479

1661

.args_doc = "",

2480

1662

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

2481

1663

" passwords from a Mandos server" };

2482

ret_errno = argp_parse(&argp, argc, argv,

2483

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2484

switch(ret_errno){

1664

ret = argp_parse(&argp, argc, argv,

1665

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1666

switch(ret){

2485

1667

case 0:

2486

1668

break;

2487

1669

case ENOMEM:

2488

1670

default:

2489

errno = ret_errno;

1671

errno = ret;

2490

1672

perror_plus("argp_parse");

2491

1673

exitcode = EX_OSERR;

2492

1674

goto end;

2495

1677

goto end;

2496

1678

}

2497

1679

}

2498

2499

{

1680

1681

if(getuid() == 0){

2500

1682

/* Work around Debian bug #633582:

2501

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

2502

2503

/* Re-raise privileges */

2504

ret = raise_privileges();

2505

if(ret != 0){

2506

errno = ret;

2507

perror_plus("Failed to raise privileges");

2508

} else {

2509

struct stat st;

2510

2511

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

2512

int seckey_fd = open(seckey, O_RDONLY);

2513

if(seckey_fd == -1){

2514

perror_plus("open");

2515

} else {

2516

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

2517

if(ret == -1){

2518

perror_plus("fstat");

2519

} else {

2520

if(S_ISREG(st.st_mode)

2521

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

2522

ret = fchown(seckey_fd, uid, gid);

2523

if(ret == -1){

2524

perror_plus("fchown");

2525

}

2526

}

2527

}

2528

close(seckey_fd);

2529

}

2530

}

2531

2532

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

2533

int pubkey_fd = open(pubkey, O_RDONLY);

2534

if(pubkey_fd == -1){

2535

perror_plus("open");

2536

} else {

2537

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

2538

if(ret == -1){

2539

perror_plus("fstat");

2540

} else {

2541

if(S_ISREG(st.st_mode)

2542

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

2543

ret = fchown(pubkey_fd, uid, gid);

2544

if(ret == -1){

2545

perror_plus("fchown");

2546

}

2547

}

2548

}

2549

close(pubkey_fd);

2550

}

2551

}

2552

2553

if(dh_params_file != NULL

2554

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

2555

int dhparams_fd = open(dh_params_file, O_RDONLY);

2556

if(dhparams_fd == -1){

2557

perror_plus("open");

2558

} else {

2559

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

2560

if(ret == -1){

2561

perror_plus("fstat");

2562

} else {

2563

if(S_ISREG(st.st_mode)

2564

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

2565

ret = fchown(dhparams_fd, uid, gid);

2566

if(ret == -1){

2567

perror_plus("fchown");

2568

}

2569

}

2570

}

2571

close(dhparams_fd);

2572

}

2573

}

2574

2575

/* Lower privileges */

2576

ret = lower_privileges();

2577

if(ret != 0){

2578

errno = ret;

2579

perror_plus("Failed to lower privileges");

2580

}

2581

}

2582

}

2583

2584

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

2585

{

2586

char *interface = NULL;

2587

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

2588

interface))){

2589

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

2590

and if_nametoindex(interface) == 0){

2591

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

2592

fprintf_plus(stderr, "Not using nonexisting interface"

2593

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

2594

}

2595

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

2596

interface = NULL;

2597

}

1683

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

1684

struct stat st;

1685

1686

/* Re-raise priviliges */

1687

errno = 0;

1688

ret = seteuid(0);

1689

if(ret == -1){

1690

perror_plus("seteuid");

1691

}

1692

1693

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

1694

int seckey_fd = open(seckey, O_RDONLY);

1695

if(seckey_fd == -1){

1696

perror_plus("open");

1697

} else {

1698

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

1699

if(ret == -1){

1700

perror_plus("fstat");

1701

} else {

1702

if(S_ISREG(st.st_mode)

1703

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

1704

ret = fchown(seckey_fd, uid, gid);

1705

if(ret == -1){

1706

perror_plus("fchown");

1707

}

1708

}

1709

}

1710

TEMP_FAILURE_RETRY(close(seckey_fd));

1711

}

1712

}

1713

1714

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

1715

int pubkey_fd = open(pubkey, O_RDONLY);

1716

if(pubkey_fd == -1){

1717

perror_plus("open");

1718

} else {

1719

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

1720

if(ret == -1){

1721

perror_plus("fstat");

1722

} else {

1723

if(S_ISREG(st.st_mode)

1724

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

1725

ret = fchown(pubkey_fd, uid, gid);

1726

if(ret == -1){

1727

perror_plus("fchown");

1728

}

1729

}

1730

}

1731

TEMP_FAILURE_RETRY(close(pubkey_fd));

1732

}

1733

}

1734

1735

/* Lower privileges */

1736

errno = 0;

1737

ret = seteuid(uid);

1738

if(ret == -1){

1739

perror_plus("seteuid");

2598

1740

}

2599

1741

}

2600

1742

2601

1743

/* Run network hooks */

2602

1744

{

2603

if(mc.interfaces != NULL){

2604

interfaces_hooks = malloc(mc.interfaces_size);

2605

if(interfaces_hooks == NULL){

2606

perror_plus("malloc");

2607

goto end;

2608

}

2609

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

2610

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

2611

}

2612

run_network_hooks("start", interfaces_hooks != NULL ?

2613

interfaces_hooks : "", delay);

1745

if(getuid() == 0){

1746

/* Re-raise priviliges */

1747

errno = 0;

1748

ret = seteuid(0);

1749

if(ret == -1){

1750

perror_plus("seteuid");

1751

}

1752

}

1753

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

1754

goto end;

1755

}

1756

if(getuid() == 0){

1757

/* Lower privileges */

1758

errno = 0;

1759

ret = seteuid(uid);

1760

if(ret == -1){

1761

perror_plus("seteuid");

1762

}

1763

}

2614

1764

}

2615

1765

2616

1766

if(not debug){

2617

1767

avahi_set_log_function(empty_log);

2618

1768

}

2619

1769

1770

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

1771

struct dirent **direntries;

1772

/* First look for interfaces that are up */

1773

ret = scandir(sys_class_net, &direntries, up_interface,

1774

alphasort);

1775

if(ret == 0){

1776

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

1777

free(direntries);

1778

ret = scandir(sys_class_net, &direntries, good_interface,

1779

alphasort);

1780

}

1781

if(ret >= 1){

1782

/* Pick the first interface returned */

1783

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

1784

if(debug){

1785

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

1786

}

1787

if(interface == NULL){

1788

perror_plus("malloc");

1789

free(direntries);

1790

exitcode = EXIT_FAILURE;

1791

goto end;

1792

}

1793

free(direntries);

1794

} else {

1795

free(direntries);

1796

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

1797

exitcode = EXIT_FAILURE;

1798

goto end;

1799

}

1800

}

1801

2620

1802

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

2621

1803

from the signal handler */

2622

1804

/* Initialize the pseudo-RNG for Avahi */

2623

1805

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

2624

simple_poll = avahi_simple_poll_new();

2625

if(simple_poll == NULL){

1806

mc.simple_poll = avahi_simple_poll_new();

1807

if(mc.simple_poll == NULL){

2626

1808

fprintf_plus(stderr,

2627

1809

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

2628

1810

exitcode = EX_UNAVAILABLE;

2692

1874

}

2693

1875

}

2694

1876

2695

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

2696

if(mc.interfaces == NULL){

2697

struct dirent **direntries = NULL;

2698

/* Look for any good interfaces */

2699

ret = scandir(sys_class_net, &direntries, good_interface,

2700

alphasort);

2701

if(ret >= 1){

2702

/* Add all found interfaces to interfaces list */

2703

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

2704

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

2705

direntries[i]->d_name);

2706

if(ret_errno != 0){

2707

errno = ret_errno;

2708

perror_plus("argz_add");

2709

free(direntries[i]);

2710

continue;

2711

}

2712

if(debug){

2713

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

2714

direntries[i]->d_name);

2715

}

2716

free(direntries[i]);

2717

}

2718

free(direntries);

2719

} else {

2720

if(ret == 0){

2721

free(direntries);

2722

}

2723

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

2724

exitcode = EXIT_FAILURE;

2725

goto end;

2726

}

2727

}

2728

2729

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

2730

{

2731

char *interface = NULL;

2732

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

2733

interface))){

2734

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

2735

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

2736

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

2737

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

2738

interface);

2739

interface = NULL;

2740

while((interface = argz_next(mc.interfaces,

2741

mc.interfaces_size, interface))){

2742

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

2743

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

2744

interface);

2745

interface = NULL;

1877

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

1878

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

1879

if_index = (AvahiIfIndex) if_nametoindex(interface);

1880

if(if_index == 0){

1881

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

1882

exitcode = EX_UNAVAILABLE;

1883

goto end;

1884

}

1885

1886

if(quit_now){

1887

goto end;

1888

}

1889

1890

/* Re-raise priviliges */

1891

errno = 0;

1892

ret = seteuid(0);

1893

if(ret == -1){

1894

perror_plus("seteuid");

1895

}

1896

1897

#ifdef __linux__

1898

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1899

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

1900

ret = klogctl(8, NULL, 5);

1901

bool restore_loglevel = true;

1902

if(ret == -1){

1903

restore_loglevel = false;

1904

perror_plus("klogctl");

1905

}

1906

#endif /* __linux__ */

1907

1908

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1909

if(sd < 0){

1910

perror_plus("socket");

1911

exitcode = EX_OSERR;

1912

#ifdef __linux__

1913

if(restore_loglevel){

1914

ret = klogctl(7, NULL, 0);

1915

if(ret == -1){

1916

perror_plus("klogctl");

1917

}

1918

}

1919

#endif /* __linux__ */

1920

/* Lower privileges */

1921

errno = 0;

1922

ret = seteuid(uid);

1923

if(ret == -1){

1924

perror_plus("seteuid");

1925

}

1926

goto end;

1927

}

1928

strcpy(network.ifr_name, interface);

1929

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

1930

if(ret == -1){

1931

perror_plus("ioctl SIOCGIFFLAGS");

1932

#ifdef __linux__

1933

if(restore_loglevel){

1934

ret = klogctl(7, NULL, 0);

1935

if(ret == -1){

1936

perror_plus("klogctl");

1937

}

1938

}

1939

#endif /* __linux__ */

1940

exitcode = EX_OSERR;

1941

/* Lower privileges */

1942

errno = 0;

1943

ret = seteuid(uid);

1944

if(ret == -1){

1945

perror_plus("seteuid");

1946

}

1947

goto end;

1948

}

1949

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

1950

network.ifr_flags |= IFF_UP;

1951

take_down_interface = true;

1952

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

1953

if(ret == -1){

1954

take_down_interface = false;

1955

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1956

exitcode = EX_OSERR;

1957

#ifdef __linux__

1958

if(restore_loglevel){

1959

ret = klogctl(7, NULL, 0);

1960

if(ret == -1){

1961

perror_plus("klogctl");

2746

1962

}

2747

1963

}

1964

#endif /* __linux__ */

1965

/* Lower privileges */

1966

errno = 0;

1967

ret = seteuid(uid);

1968

if(ret == -1){

1969

perror_plus("seteuid");

1970

}

1971

goto end;

1972

}

1973

}

1974

/* Sleep checking until interface is running.

1975

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

1976

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

1977

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

1978

if(ret == -1){

1979

perror_plus("ioctl SIOCGIFFLAGS");

1980

} else if(network.ifr_flags & IFF_RUNNING){

2748

1981

break;

2749

1982

}

2750

bool interface_was_up = interface_is_up(interface);

2751

errno = bring_up_interface(interface, delay);

2752

if(not interface_was_up){

2753

if(errno != 0){

2754

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

2755

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

2756

} else {

2757

errno = argz_add(&interfaces_to_take_down,

2758

&interfaces_to_take_down_size,

2759

interface);

2760

if(errno != 0){

2761

perror_plus("argz_add");

2762

}

2763

}

2764

}

2765

}

2766

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

2767

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

2768

}

2769

}

2770

2771

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

2772

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

2773

if(debug){

2774

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

2775

mc.interfaces);

2776

}

2777

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

1983

struct timespec sleeptime = { .tv_nsec = 250000000 };

1984

ret = nanosleep(&sleeptime, NULL);

1985

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

1986

perror_plus("nanosleep");

1987

}

1988

}

1989

if(not take_down_interface){

1990

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

1991

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

1992

if(ret == -1){

1993

perror_plus("close");

1994

}

1995

}

1996

#ifdef __linux__

1997

if(restore_loglevel){

1998

/* Restores kernel loglevel to default */

1999

ret = klogctl(7, NULL, 0);

2000

if(ret == -1){

2001

perror_plus("klogctl");

2002

}

2003

}

2004

#endif /* __linux__ */

2005

/* Lower privileges */

2006

errno = 0;

2007

/* Lower privileges */

2008

ret = seteuid(uid);

2009

if(ret == -1){

2010

perror_plus("seteuid");

2011

}

2778

2012

}

2779

2013

2780

2014

if(quit_now){

2781

2015

goto end;

2782

2016

}

2783

2017

2784

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

2018

ret = init_gnutls_global(pubkey, seckey);

2785

2019

if(ret == -1){

2786

2020

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

2787

2021

exitcode = EX_UNAVAILABLE;

2794

2028

goto end;

2795

2029

}

2796

2030

2797

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

2798

tempdir = mkdtemp(run_tempdir);

2799

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

2800

if(debug){

2801

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

2802

run_tempdir, old_tempdir);

2803

}

2804

tempdir = mkdtemp(old_tempdir);

2805

}

2806

if(tempdir == NULL){

2031

if(mkdtemp(tempdir) == NULL){

2807

2032

perror_plus("mkdtemp");

2808

2033

goto end;

2809

2034

}

2035

tempdir_created = true;

2810

2036

2811

2037

if(quit_now){

2812

2038

goto end;

2813

2039

}

2814

2040

2815

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

2041

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

2816

2042

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

2817

2043

exitcode = EX_UNAVAILABLE;

2818

2044

goto end;

2828

2054

/* Connect directly, do not use Zeroconf */

2829

2055

/* (Mainly meant for debugging) */

2830

2056

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

2831

2832

2057

if(address == NULL){

2833

2058

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

2834

2059

exitcode = EX_USAGE;

2839

2064

goto end;

2840

2065

}

2841

2066

2842

in_port_t port;

2067

uint16_t port;

2843

2068

errno = 0;

2844

2069

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

2845

2070

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

2846

or tmpmax != (in_port_t)tmpmax){

2071

or tmpmax != (uint16_t)tmpmax){

2847

2072

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

2848

2073

exitcode = EX_USAGE;

2849

2074

goto end;

2850

2075

}

2851

2076

2852

2077

if(quit_now){

2853

2078

goto end;

2854

2079

}

2855

2080

2856

port = (in_port_t)tmpmax;

2081

port = (uint16_t)tmpmax;

2857

2082

*address = '\0';

2858

2083

/* Colon in address indicates IPv6 */

2859

2084

int af;

2875

2100

}

2876

2101

2877

2102

while(not quit_now){

2878

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

2879

&mc);

2103

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

2880

2104

if(quit_now or ret == 0){

2881

2105

break;

2882

2106

}

2884

2108

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

2885

2109

(int)retry_interval);

2886

2110

}

2887

sleep((unsigned int)retry_interval);

2111

sleep((int)retry_interval);

2888

2112

}

2889

2113

2890

if(not quit_now){

2114

if (not quit_now){

2891

2115

exitcode = EXIT_SUCCESS;

2892

2116

}

2893

2117

2908

2132

config.publish_domain = 0;

2909

2133

2910

2134

/* Allocate a new server */

2911

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2912

&config, NULL, NULL, &ret);

2135

mc.server = avahi_server_new(avahi_simple_poll_get

2136

(mc.simple_poll), &config, NULL,

2137

NULL, &error);

2913

2138

2914

2139

/* Free the Avahi configuration data */

2915

2140

avahi_server_config_free(&config);

2918

2143

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

2919

2144

if(mc.server == NULL){

2920

2145

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

2921

avahi_strerror(ret));

2146

avahi_strerror(error));

2922

2147

exitcode = EX_UNAVAILABLE;

2923

2148

goto end;

2924

2149

}

2930

2155

/* Create the Avahi service browser */

2931

2156

sb = avahi_s_service_browser_new(mc.server, if_index,

2932

2157

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2933

NULL, 0, browse_callback,

2934

(void *)&mc);

2158

NULL, 0, browse_callback, NULL);

2935

2159

if(sb == NULL){

2936

2160

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

2937

2161

avahi_strerror(avahi_server_errno(mc.server)));

2948

2172

if(debug){

2949

2173

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

2950

2174

}

2951

2952

ret = avahi_loop_with_timeout(simple_poll,

2953

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

2175

2176

ret = avahi_loop_with_timeout(mc.simple_poll,

2177

(int)(retry_interval * 1000));

2954

2178

if(debug){

2955

2179

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

2956

2180

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

2959

2183

end:

2960

2184

2961

2185

if(debug){

2962

if(signal_received){

2963

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

2964

argv[0], signal_received,

2965

strsignal(signal_received));

2966

} else {

2967

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

2968

}

2186

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

2969

2187

}

2970

2188

2971

2189

/* Cleanup things */

2972

free(mc.interfaces);

2973

2974

2190

if(sb != NULL)

2975

2191

avahi_s_service_browser_free(sb);

2976

2192

2977

2193

if(mc.server != NULL)

2978

2194

avahi_server_free(mc.server);

2979

2195

2980

if(simple_poll != NULL)

2981

avahi_simple_poll_free(simple_poll);

2196

if(mc.simple_poll != NULL)

2197

avahi_simple_poll_free(mc.simple_poll);

2982

2198

2983

2199

if(gnutls_initialized){

2984

2200

gnutls_certificate_free_credentials(mc.cred);

2201

gnutls_global_deinit();

2985

2202

gnutls_dh_params_deinit(mc.dh_params);

2986

2203

}

2987

2204

2995

2212

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

2996

2213

while(mc.current_server != NULL){

2997

2214

server *next = mc.current_server->next;

2998

#ifdef __GNUC__

2999

#pragma GCC diagnostic push

3000

#pragma GCC diagnostic ignored "-Wcast-qual"

3001

#endif

3002

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

3003

#ifdef __GNUC__

3004

#pragma GCC diagnostic pop

3005

#endif

3006

2215

free(mc.current_server);

3007

2216

mc.current_server = next;

3008

2217

}

3009

2218

}

3010

2219

3011

/* Re-raise privileges */

2220

/* Re-raise priviliges */

3012

2221

{

3013

ret = raise_privileges();

3014

if(ret != 0){

3015

errno = ret;

3016

perror_plus("Failed to raise privileges");

3017

} else {

3018

3019

/* Run network hooks */

3020

run_network_hooks("stop", interfaces_hooks != NULL ?

3021

interfaces_hooks : "", delay);

3022

3023

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

3024

{

3025

char *interface = NULL;

3026

while((interface = argz_next(interfaces_to_take_down,

3027

interfaces_to_take_down_size,

3028

interface))){

3029

ret = take_down_interface(interface);

3030

if(ret != 0){

3031

errno = ret;

3032

perror_plus("Failed to take down interface");

3033

}

3034

}

3035

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

3036

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

3037

" down\n");

3038

}

3039

}

3040

}

3041

3042

ret = lower_privileges_permanently();

3043

if(ret != 0){

3044

errno = ret;

3045

perror_plus("Failed to lower privileges permanently");

3046

}

3047

}

3048

3049

free(interfaces_to_take_down);

3050

free(interfaces_hooks);

3051

3052

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

3053

uintmax_t level){

2222

if(getuid() == 0){

2223

errno = 0;

2224

ret = seteuid(0);

2225

if(ret == -1){

2226

perror_plus("seteuid");

2227

}

2228

}

2229

2230

/* Run network hooks */

2231

run_network_hooks("stop", interface, delay);

2232

2233

/* Take down the network interface */

2234

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

2235

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

2236

if(ret == -1){

2237

perror_plus("ioctl SIOCGIFFLAGS");

2238

} else if(network.ifr_flags & IFF_UP){

2239

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

2240

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

2241

if(ret == -1){

2242

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2243

}

2244

}

2245

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

2246

if(ret == -1){

2247

perror_plus("close");

2248

}

2249

}

2250

}

2251

if(getuid() == 0){

2252

/* Lower privileges permanently */

2253

errno = 0;

2254

ret = setuid(uid);

2255

if(ret == -1){

2256

perror_plus("setuid");

2257

}

2258

}

2259

2260

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

2261

if(tempdir_created){

3054

2262

struct dirent **direntries = NULL;

3055

int dret;

3056

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

3057

O_RDONLY

3058

| O_NOFOLLOW

3059

| O_DIRECTORY

3060

| O_PATH));

3061

if(dir_fd == -1){

3062

perror_plus("open");

3063

}

3064

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

3065

notdotentries, alphasort);

3066

if(numentries >= 0){

2263

struct dirent *direntry = NULL;

2264

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

2265

alphasort);

2266

if (numentries > 0){

3067

2267

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

3068

if(debug){

3069

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

3070

dirname, direntries[i]->d_name);

3071

}

3072

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

3073

if(dret == -1){

3074

if(errno == EISDIR){

3075

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

3076

AT_REMOVEDIR);

3077

}

3078

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

3079

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

3080

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

3081

/* Recurse only in this special case */

3082

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

3083

dret = 0;

3084

}

3085

if(dret == -1){

3086

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

3087

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

3088

}

3089

}

3090

free(direntries[i]);

3091

}

3092

3093

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

3094

free(direntries);

3095

if(numentries == -1){

3096

perror_plus("scandirat");

3097

}

3098

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3099

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

3100

perror_plus("rmdir");

3101

}

3102

} else {

3103

perror_plus("scandirat");

3104

}

3105

close(dir_fd);

3106

}

3107

3108

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

3109

if(tempdir != NULL){

3110

clean_dir_at(-1, tempdir, 0);

2268

direntry = direntries[i];

2269

char *fullname = NULL;

2270

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

2271

direntry->d_name);

2272

if(ret < 0){

2273

perror_plus("asprintf");

2274

continue;

2275

}

2276

ret = remove(fullname);

2277

if(ret == -1){

2278

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

2279

strerror(errno));

2280

}

2281

free(fullname);

2282

}

2283

}

2284

2285

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

2286

free(direntries);

2287

if (numentries == -1){

2288

perror_plus("scandir");

2289

}

2290

ret = rmdir(tempdir);

2291

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

2292

perror_plus("rmdir");

2293

}

3111

2294

}

3112

2295

3113

2296

if(quit_now){