/mandos/release : revision 237.7.493

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

10

*

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* Everything else is

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*

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

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

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* published by the Free Software Foundation, either version 3 of the

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* License, or (at your option) any later version.

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*

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* This program is distributed in the hope that it will be useful, but

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13

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*

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* This file is part of Mandos.

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*

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* Mandos is free software: you can redistribute it and/or modify it

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* under the terms of the GNU General Public License as published by

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* the Free Software Foundation, either version 3 of the License, or

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* (at your option) any later version.

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*

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* Mandos is distributed in the hope that it will be useful, but

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* WITHOUT ANY WARRANTY; without even the implied warranty of

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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

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25

* General Public License for more details.

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26

*

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* You should have received a copy of the GNU General Public License

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* along with this program. If not, see

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* <http://www.gnu.org/licenses/>.

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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

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*

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* Contact the authors at <mandos@recompile.se>.

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31

*/

32

33

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

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34

#ifndef _LARGEFILE_SOURCE

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35

#define _LARGEFILE_SOURCE

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#endif

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#endif /* not _LARGEFILE_SOURCE */

36

37

#ifndef _FILE_OFFSET_BITS

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38

#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

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40

41

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

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42

43

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

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stdout, ferror(), remove() */

44

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

44

stdout, ferror() */

45

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

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46

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

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

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48

strtof(), abort() */

48

49

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

49

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

50

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

50

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

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asprintf(), strncpy(), strsignal()

52

*/

51

53

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

52

54

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

53

55

sockaddr_in6, PF_INET6,

55

57

opendir(), DIR */

56

58

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

57

59

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

58

inet_pton(), connect() */

59

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

60

inet_pton(), connect(),

61

getnameinfo() */

62

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

60

63

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

61

64

*/

62

65

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

63

66

strtoimax() */

64

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

65

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

67

#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,

71

ENOTEMPTY,

66

72

program_invocation_short_name */

67

73

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

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74

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

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79

*/

74

80

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

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

76

setgid(), pause() */

77

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

82

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

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unlinkat() */

84

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

78

85

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

79

86

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

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87

argp_state, struct argp,

87

94

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

88

95

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

89

96

WEXITSTATUS(), WTERMSIG() */

97

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

98

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

99

argz_delete(), argz_append(),

100

argz_stringify(), argz_add(),

101

argz_count() */

102

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

103

EAI_SYSTEM, gai_strerror() */

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104

91

105

#ifdef __linux__

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106

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

134

148

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

135

149

char *connect_to = NULL;

136

150

const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

152

uid_t uid = 65534;

153

gid_t gid = 65534;

137

154

138

155

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

139

156

typedef struct server{

140

157

const char *ip;

141

uint16_t port;

158

in_port_t port;

142

159

AvahiIfIndex if_index;

143

160

int af;

144

161

struct timespec last_seen;

148

165

149

166

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

150

167

typedef struct {

151

AvahiSimplePoll *simple_poll;

152

168

AvahiServer *server;

153

169

gnutls_certificate_credentials_t cred;

154

170

unsigned int dh_bits;

156

172

const char *priority;

157

173

gpgme_ctx_t ctx;

158

174

server *current_server;

175

char *interfaces;

176

size_t interfaces_size;

159

177

} mandos_context;

160

178

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 };

179

/* global so signal handler can reach it*/

180

AvahiSimplePoll *simple_poll;

166

181

167

182

sig_atomic_t quit_now = 0;

168

183

int signal_received = 0;

169

184

170

185

/* Function to use when printing errors */

171

186

void perror_plus(const char *print_text){

187

int e = errno;

172

188

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

173

189

program_invocation_short_name);

190

errno = e;

174

191

perror(print_text);

175

192

}

176

193

194

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

177

195

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

178

196

va_list ap;

179

197

va_start (ap, format);

180

198

181

199

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

182

200

program_invocation_short_name));

183

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

201

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

184

202

}

185

203

186

204

/*

188

206

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

189

207

* "buffer_length" is how much is already used.

190

208

*/

209

__attribute__((nonnull, warn_unused_result))

191

210

size_t incbuffer(char **buffer, size_t buffer_length,

192

211

size_t buffer_capacity){

193

212

if(buffer_length + BUFFER_SIZE > buffer_capacity){

194

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

195

if(buffer == NULL){

213

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

214

if(new_buf == NULL){

215

int old_errno = errno;

216

free(*buffer);

217

errno = old_errno;

218

*buffer = NULL;

196

219

return 0;

197

220

}

221

*buffer = new_buf;

198

222

buffer_capacity += BUFFER_SIZE;

199

223

}

200

224

return buffer_capacity;

201

225

}

202

226

203

227

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

204

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

205

int af){

228

__attribute__((nonnull, warn_unused_result))

229

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

230

int af, server **current_server){

206

231

int ret;

207

232

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

208

233

if(new_server == NULL){

209

234

perror_plus("malloc");

210

return -1;

235

return false;

211

236

}

212

237

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

213

238

.port = port,

215

240

.af = af };

216

241

if(new_server->ip == NULL){

217

242

perror_plus("strdup");

218

return -1;

243

free(new_server);

244

return false;

245

}

246

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

247

if(ret == -1){

248

perror_plus("clock_gettime");

249

#ifdef __GNUC__

250

#pragma GCC diagnostic push

251

#pragma GCC diagnostic ignored "-Wcast-qual"

252

#endif

253

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

254

#ifdef __GNUC__

255

#pragma GCC diagnostic pop

256

#endif

257

free(new_server);

258

return false;

219

259

}

220

260

/* Special case of first server */

221

if (mc.current_server == NULL){

261

if(*current_server == NULL){

222

262

new_server->next = new_server;

223

263

new_server->prev = new_server;

224

mc.current_server = new_server;

225

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

264

*current_server = new_server;

226

265

} else {

227

new_server->next = mc.current_server;

228

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

266

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

267

new_server->next = *current_server;

268

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

229

269

new_server->prev->next = new_server;

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;

270

(*current_server)->prev = new_server;

271

}

272

return true;

238

273

}

239

274

240

275

/*

241

276

* Initialize GPGME.

242

277

*/

243

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

244

const char *tempdir){

278

__attribute__((nonnull, warn_unused_result))

279

static bool init_gpgme(const char * const seckey,

280

const char * const pubkey,

281

const char * const tempdir,

282

mandos_context *mc){

245

283

gpgme_error_t rc;

246

284

gpgme_engine_info_t engine_info;

247

285

248

249

286

/*

250

287

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

251

288

*/

252

bool import_key(const char *filename){

289

bool import_key(const char * const filename){

253

290

int ret;

254

291

int fd;

255

292

gpgme_data_t pgp_data;

267

304

return false;

268

305

}

269

306

270

rc = gpgme_op_import(mc.ctx, pgp_data);

307

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

271

308

if(rc != GPG_ERR_NO_ERROR){

272

309

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

273

310

gpgme_strsource(rc), gpgme_strerror(rc));

274

311

return false;

275

312

}

276

313

277

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

314

ret = close(fd);

278

315

if(ret == -1){

279

316

perror_plus("close");

280

317

}

317

354

}

318

355

319

356

/* Create new GPGME "context" */

320

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

357

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

321

358

if(rc != GPG_ERR_NO_ERROR){

322

359

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

323

360

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

336

373

* Decrypt OpenPGP data.

337

374

* Returns -1 on error

338

375

*/

376

__attribute__((nonnull, warn_unused_result))

339

377

static ssize_t pgp_packet_decrypt(const char *cryptotext,

340

378

size_t crypto_size,

341

char **plaintext){

379

char **plaintext,

380

mandos_context *mc){

342

381

gpgme_data_t dh_crypto, dh_plain;

343

382

gpgme_error_t rc;

344

383

ssize_t ret;

370

409

371

410

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

372

411

data buffer */

373

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

412

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

374

413

if(rc != GPG_ERR_NO_ERROR){

375

414

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

376

415

gpgme_strsource(rc), gpgme_strerror(rc));

377

416

plaintext_length = -1;

378

417

if(debug){

379

418

gpgme_decrypt_result_t result;

380

result = gpgme_op_decrypt_result(mc.ctx);

419

result = gpgme_op_decrypt_result(mc->ctx);

381

420

if(result == NULL){

382

421

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

383

422

} else {

384

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

385

result->unsupported_algorithm);

386

fprintf_plus(stderr, "Wrong key usage: %u\n",

387

result->wrong_key_usage);

423

if(result->unsupported_algorithm != NULL) {

424

fprintf_plus(stderr, "Unsupported algorithm: %s\n",

425

result->unsupported_algorithm);

426

}

427

fprintf_plus(stderr, "Wrong key usage: %s\n",

428

result->wrong_key_usage ? "Yes" : "No");

388

429

if(result->file_name != NULL){

389

430

fprintf_plus(stderr, "File name: %s\n", result->file_name);

390

431

}

460

501

return plaintext_length;

461

502

}

462

503

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;

504

__attribute__((warn_unused_result, const))

505

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

506

if(str == NULL)

507

return "(unknown)";

508

return str;

509

}

510

511

__attribute__((warn_unused_result))

512

static const char *safer_gnutls_strerror(int value){

513

const char *ret = gnutls_strerror(value);

514

return safe_string(ret);

469

515

}

470

516

471

517

/* GnuTLS log function callback */

518

__attribute__((nonnull))

472

519

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

473

520

const char* string){

474

521

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

475

522

}

476

523

524

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

477

525

static int init_gnutls_global(const char *pubkeyfilename,

478

const char *seckeyfilename){

526

const char *seckeyfilename,

527

const char *dhparamsfilename,

528

mandos_context *mc){

479

529

int ret;

530

unsigned int uret;

480

531

481

532

if(debug){

482

533

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

483

534

}

484

535

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

492

536

if(debug){

493

537

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

494

538

* - GnuTLS manual

498

542

}

499

543

500

544

/* OpenPGP credentials */

501

ret = gnutls_certificate_allocate_credentials(&mc.cred);

545

ret = gnutls_certificate_allocate_credentials(&mc->cred);

502

546

if(ret != GNUTLS_E_SUCCESS){

503

547

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

504

548

safer_gnutls_strerror(ret));

505

gnutls_global_deinit();

506

549

return -1;

507

550

}

508

551

514

557

}

515

558

516

559

ret = gnutls_certificate_set_openpgp_key_file

517

(mc.cred, pubkeyfilename, seckeyfilename,

560

(mc->cred, pubkeyfilename, seckeyfilename,

518

561

GNUTLS_OPENPGP_FMT_BASE64);

519

562

if(ret != GNUTLS_E_SUCCESS){

520

563

fprintf_plus(stderr,

526

569

}

527

570

528

571

/* GnuTLS server initialization */

529

ret = gnutls_dh_params_init(&mc.dh_params);

572

ret = gnutls_dh_params_init(&mc->dh_params);

530

573

if(ret != GNUTLS_E_SUCCESS){

531

574

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

532

575

" initialization: %s\n",

533

576

safer_gnutls_strerror(ret));

534

577

goto globalfail;

535

578

}

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);

579

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

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

ret = close(dhpfile);

619

if(ret == -1){

620

perror_plus("close");

621

}

622

if(params.data == NULL){

623

dhparamsfilename = NULL;

624

}

625

if(dhparamsfilename == NULL){

626

break;

627

}

628

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

629

GNUTLS_X509_FMT_PEM);

630

if(ret != GNUTLS_E_SUCCESS){

631

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

632

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

633

safer_gnutls_strerror(ret));

634

dhparamsfilename = NULL;

635

}

636

free(params.data);

637

} while(false);

638

}

639

if(dhparamsfilename == NULL){

640

if(mc->dh_bits == 0){

641

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

642

/* Try to read the private key file */

643

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

644

do {

645

int secfile = open(seckeyfilename, O_RDONLY);

646

if(secfile == -1){

647

perror_plus("open");

648

break;

649

}

650

size_t buffer_capacity = 0;

651

while(true){

652

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

653

(size_t)buffer.size,

654

(size_t)buffer_capacity);

655

if(buffer_capacity == 0){

656

perror_plus("incbuffer");

657

free(buffer.data);

658

buffer.data = NULL;

659

break;

660

}

661

ssize_t bytes_read = read(secfile,

662

buffer.data + buffer.size,

663

BUFFER_SIZE);

664

/* EOF */

665

if(bytes_read == 0){

666

break;

667

}

668

/* check bytes_read for failure */

669

if(bytes_read < 0){

670

perror_plus("read");

671

free(buffer.data);

672

buffer.data = NULL;

673

break;

674

}

675

buffer.size += (unsigned int)bytes_read;

676

}

677

close(secfile);

678

} while(false);

679

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

680

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

681

if(buffer.data != NULL){

682

{

683

gnutls_openpgp_privkey_t privkey = NULL;

684

ret = gnutls_openpgp_privkey_init(&privkey);

685

if(ret != GNUTLS_E_SUCCESS){

686

fprintf_plus(stderr, "Error initializing OpenPGP key"

687

" structure: %s",

688

safer_gnutls_strerror(ret));

689

free(buffer.data);

690

buffer.data = NULL;

691

} else {

692

ret = gnutls_openpgp_privkey_import

693

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

694

if(ret != GNUTLS_E_SUCCESS){

695

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

696

safer_gnutls_strerror(ret));

697

privkey = NULL;

698

}

699

free(buffer.data);

700

buffer.data = NULL;

701

if(privkey != NULL){

702

/* Use private key to suggest an appropriate

703

sec_param */

704

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

705

gnutls_openpgp_privkey_deinit(privkey);

706

if(debug){

707

fprintf_plus(stderr, "This OpenPGP key implies using"

708

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

709

safe_string(gnutls_sec_param_get_name

710

(sec_param)));

711

}

712

}

713

}

714

}

715

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

716

/* Err on the side of caution */

717

sec_param = GNUTLS_SEC_PARAM_ULTRA;

718

if(debug){

719

fprintf_plus(stderr, "Falling back to security parameter"

720

" \"%s\"\n",

721

safe_string(gnutls_sec_param_get_name

722

(sec_param)));

723

}

724

}

725

}

726

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

727

if(uret != 0){

728

mc->dh_bits = uret;

729

if(debug){

730

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

731

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

732

safe_string(gnutls_sec_param_get_name

733

(sec_param)),

734

mc->dh_bits);

735

}

736

} else {

737

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

738

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

739

safe_string(gnutls_sec_param_get_name

740

(sec_param)),

741

safer_gnutls_strerror(ret));

742

goto globalfail;

743

}

744

} else if(debug){

745

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

746

mc->dh_bits);

747

}

748

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

749

if(ret != GNUTLS_E_SUCCESS){

750

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

751

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

752

safer_gnutls_strerror(ret));

753

goto globalfail;

754

}

755

}

756

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

544

757

545

758

return 0;

546

759

547

760

globalfail:

548

761

549

gnutls_certificate_free_credentials(mc.cred);

550

gnutls_global_deinit();

551

gnutls_dh_params_deinit(mc.dh_params);

762

gnutls_certificate_free_credentials(mc->cred);

763

gnutls_dh_params_deinit(mc->dh_params);

552

764

return -1;

553

765

}

554

766

555

static int init_gnutls_session(gnutls_session_t *session){

767

__attribute__((nonnull, warn_unused_result))

768

static int init_gnutls_session(gnutls_session_t *session,

769

mandos_context *mc){

556

770

int ret;

557

771

/* GnuTLS session creation */

558

772

do {

570

784

{

571

785

const char *err;

572

786

do {

573

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

787

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

574

788

if(quit_now){

575

789

gnutls_deinit(*session);

576

790

return -1;

587

801

588

802

do {

589

803

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

590

mc.cred);

804

mc->cred);

591

805

if(quit_now){

592

806

gnutls_deinit(*session);

593

807

return -1;

603

817

/* ignore client certificate if any. */

604

818

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

605

819

606

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

607

608

820

return 0;

609

821

}

610

822

612

824

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

613

825

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

614

826

827

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

828

__attribute__((warn_unused_result))

829

int raise_privileges(void){

830

int old_errno = errno;

831

int ret = 0;

832

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

833

ret = errno;

834

}

835

errno = old_errno;

836

return ret;

837

}

838

839

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

840

__attribute__((warn_unused_result))

841

int raise_privileges_permanently(void){

842

int old_errno = errno;

843

int ret = raise_privileges();

844

if(ret != 0){

845

errno = old_errno;

846

return ret;

847

}

848

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

849

ret = errno;

850

}

851

errno = old_errno;

852

return ret;

853

}

854

855

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

856

__attribute__((warn_unused_result))

857

int lower_privileges(void){

858

int old_errno = errno;

859

int ret = 0;

860

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

861

ret = errno;

862

}

863

errno = old_errno;

864

return ret;

865

}

866

867

/* Lower privileges permanently */

868

__attribute__((warn_unused_result))

869

int lower_privileges_permanently(void){

870

int old_errno = errno;

871

int ret = 0;

872

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

873

ret = errno;

874

}

875

errno = old_errno;

876

return ret;

877

}

878

879

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

880

__attribute__((nonnull, warn_unused_result))

881

static bool add_delete_local_route(const bool add,

882

const char *address,

883

AvahiIfIndex if_index){

884

int ret;

885

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

886

char add_arg[] = "add";

887

char delete_arg[] = "delete";

888

char debug_flag[] = "--debug";

889

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

890

if(pluginhelperdir == NULL){

891

if(debug){

892

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

893

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

894

}

895

return false;

896

}

897

898

char interface[IF_NAMESIZE];

899

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

900

perror_plus("if_indextoname");

901

return false;

902

}

903

904

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

905

if(devnull == -1){

906

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

907

return false;

908

}

909

pid_t pid = fork();

910

if(pid == 0){

911

/* Child */

912

/* Raise privileges */

913

errno = raise_privileges_permanently();

914

if(errno != 0){

915

perror_plus("Failed to raise privileges");

916

/* _exit(EX_NOPERM); */

917

} else {

918

/* Set group */

919

errno = 0;

920

ret = setgid(0);

921

if(ret == -1){

922

perror_plus("setgid");

923

_exit(EX_NOPERM);

924

}

925

/* Reset supplementary groups */

926

errno = 0;

927

ret = setgroups(0, NULL);

928

if(ret == -1){

929

perror_plus("setgroups");

930

_exit(EX_NOPERM);

931

}

932

}

933

ret = dup2(devnull, STDIN_FILENO);

934

if(ret == -1){

935

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

936

_exit(EX_OSERR);

937

}

938

ret = close(devnull);

939

if(ret == -1){

940

perror_plus("close");

941

_exit(EX_OSERR);

942

}

943

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

944

if(ret == -1){

945

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

946

_exit(EX_OSERR);

947

}

948

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

949

O_RDONLY

950

| O_DIRECTORY

951

| O_PATH

952

| O_CLOEXEC));

953

if(helperdir_fd == -1){

954

perror_plus("open");

955

_exit(EX_UNAVAILABLE);

956

}

957

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

958

helper, O_RDONLY));

959

if(helper_fd == -1){

960

perror_plus("openat");

961

close(helperdir_fd);

962

_exit(EX_UNAVAILABLE);

963

}

964

close(helperdir_fd);

965

#ifdef __GNUC__

966

#pragma GCC diagnostic push

967

#pragma GCC diagnostic ignored "-Wcast-qual"

968

#endif

969

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

970

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

971

interface, debug ? debug_flag : NULL, NULL },

972

environ) == -1){

973

#ifdef __GNUC__

974

#pragma GCC diagnostic pop

975

#endif

976

perror_plus("fexecve");

977

_exit(EXIT_FAILURE);

978

}

979

}

980

if(pid == -1){

981

perror_plus("fork");

982

return false;

983

}

984

int status;

985

pid_t pret = -1;

986

errno = 0;

987

do {

988

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

989

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

990

int errno_raising = 0;

991

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

992

errno_raising = errno;

993

perror_plus("Failed to raise privileges in order to"

994

" kill helper program");

995

}

996

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

997

perror_plus("kill");

998

}

999

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

1000

perror_plus("Failed to lower privileges after killing"

1001

" helper program");

1002

}

1003

return false;

1004

}

1005

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

1006

if(pret == -1){

1007

perror_plus("waitpid");

1008

return false;

1009

}

1010

if(WIFEXITED(status)){

1011

if(WEXITSTATUS(status) != 0){

1012

fprintf_plus(stderr, "Error: iprouteadddel exited"

1013

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

1014

return false;

1015

}

1016

return true;

1017

}

1018

if(WIFSIGNALED(status)){

1019

fprintf_plus(stderr, "Error: iprouteadddel died by"

1020

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

1021

return false;

1022

}

1023

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

1024

return false;

1025

}

1026

1027

__attribute__((nonnull, warn_unused_result))

1028

static bool add_local_route(const char *address,

1029

AvahiIfIndex if_index){

1030

if(debug){

1031

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

1032

}

1033

return add_delete_local_route(true, address, if_index);

1034

}

1035

1036

__attribute__((nonnull, warn_unused_result))

1037

static bool delete_local_route(const char *address,

1038

AvahiIfIndex if_index){

1039

if(debug){

1040

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

1041

}

1042

return add_delete_local_route(false, address, if_index);

1043

}

1044

615

1045

/* Called when a Mandos server is found */

616

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

1046

__attribute__((nonnull, warn_unused_result))

1047

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

617

1048

AvahiIfIndex if_index,

618

int af){

1049

int af, mandos_context *mc){

619

1050

int ret, tcp_sd = -1;

620

1051

ssize_t sret;

621

union {

622

struct sockaddr_in in;

623

struct sockaddr_in6 in6;

624

} to;

1052

struct sockaddr_storage to;

625

1053

char *buffer = NULL;

626

1054

char *decrypted_buffer = NULL;

627

1055

size_t buffer_length = 0;

630

1058

int retval = -1;

631

1059

gnutls_session_t session;

632

1060

int pf; /* Protocol family */

1061

bool route_added = false;

633

1062

634

1063

errno = 0;

635

1064

651

1080

return -1;

652

1081

}

653

1082

654

ret = init_gnutls_session(&session);

1083

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

1084

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

1085

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

1086

bool match = false;

1087

{

1088

char *interface = NULL;

1089

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

1090

mc->interfaces_size,

1091

interface))){

1092

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

1093

match = true;

1094

break;

1095

}

1096

}

1097

}

1098

if(not match){

1099

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

1100

connect to the server */

1101

if(debug){

1102

char interface[IF_NAMESIZE];

1103

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

1104

perror_plus("if_indextoname");

1105

} else {

1106

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

1107

" \"%s\"\n",

1108

if_indextoname((unsigned int)if_index,

1109

interface));

1110

}

1111

}

1112

return -1;

1113

}

1114

}

1115

1116

ret = init_gnutls_session(&session, mc);

655

1117

if(ret != 0){

656

1118

return -1;

657

1119

}

658

1120

659

1121

if(debug){

660

1122

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

661

PRIu16 "\n", ip, port);

1123

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

662

1124

}

663

1125

664

tcp_sd = socket(pf, SOCK_STREAM, 0);

1126

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

665

1127

if(tcp_sd < 0){

666

1128

int e = errno;

667

1129

perror_plus("socket");

674

1136

goto mandos_end;

675

1137

}

676

1138

677

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

678

1139

if(af == AF_INET6){

679

to.in6.sin6_family = (sa_family_t)af;

680

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

1140

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

1141

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

1142

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

681

1143

} else { /* IPv4 */

682

to.in.sin_family = (sa_family_t)af;

683

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

1144

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

1145

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

1146

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

684

1147

}

685

1148

if(ret < 0 ){

686

1149

int e = errno;

695

1158

goto mandos_end;

696

1159

}

697

1160

if(af == AF_INET6){

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*/

1161

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

1162

if(IN6_IS_ADDR_LINKLOCAL

1163

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

705

1164

if(if_index == AVAHI_IF_UNSPEC){

706

1165

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

707

1166

" incomplete without a network interface\n");

709

1168

goto mandos_end;

710

1169

}

711

1170

/* Set the network interface number as scope */

712

to.in6.sin6_scope_id = (uint32_t)if_index;

1171

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

713

1172

}

714

1173

} else {

715

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

716

-Wconversion and

717

-Wunreachable-code */

1174

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

718

1175

}

719

1176

720

1177

if(quit_now){

728

1185

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

729

1186

perror_plus("if_indextoname");

730

1187

} else {

731

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

732

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

1188

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

1189

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

733

1190

}

734

1191

} else {

735

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

736

ip, port);

1192

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

1193

ip, (uintmax_t)port);

737

1194

}

738

1195

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

739

1196

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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;

1197

if(af == AF_INET6){

1198

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

1199

sizeof(struct sockaddr_in6),

1200

addrstr, sizeof(addrstr), NULL, 0,

1201

NI_NUMERICHOST);

1202

} else {

1203

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

1204

sizeof(struct sockaddr_in),

1205

addrstr, sizeof(addrstr), NULL, 0,

1206

NI_NUMERICHOST);

1207

}

1208

if(ret == EAI_SYSTEM){

1209

perror_plus("getnameinfo");

1210

} else if(ret != 0) {

1211

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

1212

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

1213

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

1214

}

1215

}

1216

1217

if(quit_now){

1218

errno = EINTR;

1219

goto mandos_end;

1220

}

1221

1222

while(true){

1223

if(af == AF_INET6){

1224

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

1225

sizeof(struct sockaddr_in6));

1226

} else {

1227

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

1228

sizeof(struct sockaddr_in));

1229

}

1230

if(ret < 0){

1231

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

1232

and if_index != AVAHI_IF_UNSPEC

1233

and connect_to == NULL

1234

and not route_added and

1235

((af == AF_INET6 and not

1236

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1237

&to)->sin6_addr)))

1238

or (af == AF_INET and

1239

/* Not a a IPv4LL address */

1240

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

1241

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

1242

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

1243

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

1244

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

1245

connect to a Mandos server announced by Avahi on a server

1246

host with a global address. Work around this by retrying

1247

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

1248

1249

Avahi bug reference:

1250

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

1251

https://bugs.debian.org/587961

1252

*/

1253

if(debug){

1254

fprintf_plus(stderr, "Mandos server unreachable, trying"

1255

" direct route\n");

1256

}

1257

int e = errno;

1258

route_added = add_local_route(ip, if_index);

1259

if(route_added){

1260

continue;

1261

}

1262

errno = e;

1263

}

1264

if(errno != ECONNREFUSED or debug){

1265

int e = errno;

1266

perror_plus("connect");

1267

errno = e;

1268

}

1269

goto mandos_end;

1270

}

1271

1272

if(quit_now){

1273

errno = EINTR;

1274

goto mandos_end;

1275

}

1276

break;

779

1277

}

780

1278

781

1279

const char *out = mandos_protocol_version;

817

1315

goto mandos_end;

818

1316

}

819

1317

820

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

821

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1318

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

1319

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

1320

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

1321

gnutls_transport_set_ptr(session,

1322

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

822

1323

823

1324

if(quit_now){

824

1325

errno = EINTR;

929

1430

if(buffer_length > 0){

930

1431

ssize_t decrypted_buffer_size;

931

1432

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

932

&decrypted_buffer);

1433

&decrypted_buffer, mc);

933

1434

if(decrypted_buffer_size >= 0){

934

1435

1436

clearerr(stdout);

935

1437

written = 0;

936

1438

while(written < (size_t) decrypted_buffer_size){

937

1439

if(quit_now){

953

1455

}

954

1456

written += (size_t)ret;

955

1457

}

1458

ret = fflush(stdout);

1459

if(ret != 0){

1460

int e = errno;

1461

if(debug){

1462

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

1463

strerror(errno));

1464

}

1465

errno = e;

1466

goto mandos_end;

1467

}

956

1468

retval = 0;

957

1469

}

958

1470

}

961

1473

962

1474

mandos_end:

963

1475

{

1476

if(route_added){

1477

if(not delete_local_route(ip, if_index)){

1478

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

1479

" interface %d", ip, if_index);

1480

}

1481

}

964

1482

int e = errno;

965

1483

free(decrypted_buffer);

966

1484

free(buffer);

967

1485

if(tcp_sd >= 0){

968

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

1486

ret = close(tcp_sd);

969

1487

}

970

1488

if(ret == -1){

971

1489

if(e == 0){

996

1514

AVAHI_GCC_UNUSED AvahiStringList *txt,

997

1515

AVAHI_GCC_UNUSED AvahiLookupResultFlags

998

1516

flags,

999

AVAHI_GCC_UNUSED void* userdata){

1000

assert(r);

1517

void *mc){

1518

if(r == NULL){

1519

return;

1520

}

1001

1521

1002

1522

/* Called whenever a service has been resolved successfully or

1003

1523

timed out */

1004

1524

1005

1525

if(quit_now){

1526

avahi_s_service_resolver_free(r);

1006

1527

return;

1007

1528

}

1008

1529

1012

1533

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

1013

1534

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

1014

1535

domain,

1015

avahi_strerror(avahi_server_errno(mc.server)));

1536

avahi_strerror(avahi_server_errno

1537

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

1016

1538

break;

1017

1539

1018

1540

case AVAHI_RESOLVER_FOUND:

1024

1546

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

1025

1547

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

1026

1548

}

1027

int ret = start_mandos_communication(ip, port, interface,

1028

avahi_proto_to_af(proto));

1549

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

1550

interface,

1551

avahi_proto_to_af(proto),

1552

mc);

1029

1553

if(ret == 0){

1030

avahi_simple_poll_quit(mc.simple_poll);

1554

avahi_simple_poll_quit(simple_poll);

1031

1555

} else {

1032

ret = add_server(ip, port, interface,

1033

avahi_proto_to_af(proto));

1556

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

1557

avahi_proto_to_af(proto),

1558

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

1559

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

1560

" list\n", name);

1561

}

1034

1562

}

1035

1563

}

1036

1564

}

1046

1574

const char *domain,

1047

1575

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1048

1576

flags,

1049

AVAHI_GCC_UNUSED void* userdata){

1050

assert(b);

1577

void *mc){

1578

if(b == NULL){

1579

return;

1580

}

1051

1581

1052

1582

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

1053

1583

is removed from the LAN */

1061

1591

case AVAHI_BROWSER_FAILURE:

1062

1592

1063

1593

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

1064

avahi_strerror(avahi_server_errno(mc.server)));

1065

avahi_simple_poll_quit(mc.simple_poll);

1594

avahi_strerror(avahi_server_errno

1595

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

1596

avahi_simple_poll_quit(simple_poll);

1066

1597

return;

1067

1598

1068

1599

case AVAHI_BROWSER_NEW:

1071

1602

the callback function is called the Avahi server will free the

1072

1603

resolver for us. */

1073

1604

1074

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

1075

name, type, domain, protocol, 0,

1076

resolve_callback, NULL) == NULL)

1605

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

1606

interface, protocol, name, type,

1607

domain, protocol, 0,

1608

resolve_callback, mc) == NULL)

1077

1609

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

1078

1610

" %s\n", name,

1079

avahi_strerror(avahi_server_errno(mc.server)));

1611

avahi_strerror(avahi_server_errno

1612

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

1080

1613

break;

1081

1614

1082

1615

case AVAHI_BROWSER_REMOVE:

1101

1634

signal_received = sig;

1102

1635

int old_errno = errno;

1103

1636

/* set main loop to exit */

1104

if(mc.simple_poll != NULL){

1105

avahi_simple_poll_quit(mc.simple_poll);

1637

if(simple_poll != NULL){

1638

avahi_simple_poll_quit(simple_poll);

1106

1639

}

1107

1640

errno = old_errno;

1108

1641

}

1109

1642

1643

__attribute__((nonnull, warn_unused_result))

1110

1644

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

1111

1645

int ret;

1646

int old_errno;

1112

1647

1113

1648

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

1114

1649

if(s < 0){

1650

old_errno = errno;

1115

1651

perror_plus("socket");

1652

errno = old_errno;

1116

1653

return false;

1117

1654

}

1118

strcpy(ifr->ifr_name, ifname);

1655

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

1656

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

1119

1657

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1120

1658

if(ret == -1){

1121

1659

if(debug){

1660

old_errno = errno;

1122

1661

perror_plus("ioctl SIOCGIFFLAGS");

1662

errno = old_errno;

1663

}

1664

if((close(s) == -1) and debug){

1665

old_errno = errno;

1666

perror_plus("close");

1667

errno = old_errno;

1123

1668

}

1124

1669

return false;

1125

1670

}

1671

if((close(s) == -1) and debug){

1672

old_errno = errno;

1673

perror_plus("close");

1674

errno = old_errno;

1675

}

1126

1676

return true;

1127

1677

}

1128

1678

1679

__attribute__((nonnull, warn_unused_result))

1129

1680

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

1130

1681

1131

1682

/* Reject the loopback device */

1173

1724

* corresponds to an acceptable network device.

1174

1725

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

1175

1726

*/

1727

__attribute__((nonnull, warn_unused_result))

1176

1728

int good_interface(const struct dirent *if_entry){

1177

1729

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

1178

1730

return 0;

1194

1746

}

1195

1747

1196

1748

/*

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

1749

* This function determines if a network interface is up.

1750

*/

1751

__attribute__((nonnull, warn_unused_result))

1752

bool interface_is_up(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_UP);

1763

}

1764

1765

/*

1766

* This function determines if a network interface is running

1767

*/

1768

__attribute__((nonnull, warn_unused_result))

1769

bool interface_is_running(const char *interface){

1770

struct ifreq ifr;

1771

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

1772

if(debug){

1773

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

1774

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

1775

}

1776

return false;

1777

}

1778

1779

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

1780

}

1781

1782

__attribute__((nonnull, pure, warn_unused_result))

1239

1783

int notdotentries(const struct dirent *direntry){

1240

1784

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

1241

1785

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

1248

1792

}

1249

1793

1250

1794

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

1795

__attribute__((nonnull, warn_unused_result))

1251

1796

int runnable_hook(const struct dirent *direntry){

1252

1797

int ret;

1253

1798

size_t sret;

1261

1806

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

1262

1807

"abcdefghijklmnopqrstuvwxyz"

1263

1808

"0123456789"

1264

"_-");

1809

"_.-");

1265

1810

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

1266

1811

/* Contains non-allowed characters */

1267

1812

if(debug){

1271

1816

return 0;

1272

1817

}

1273

1818

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);

1819

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

1282

1820

if(ret == -1){

1283

1821

if(debug){

1284

1822

perror_plus("Could not stat hook");

1301

1839

}

1302

1840

return 0;

1303

1841

}

1842

if(debug){

1843

fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",

1844

direntry->d_name);

1845

}

1304

1846

return 1;

1305

1847

}

1306

1848

1307

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1849

__attribute__((nonnull, warn_unused_result))

1850

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1851

mandos_context *mc){

1308

1852

int ret;

1309

1853

struct timespec now;

1310

1854

struct timespec waited_time;

1311

1855

intmax_t block_time;

1312

1856

1313

1857

while(true){

1314

if(mc.current_server == NULL){

1315

if (debug){

1858

if(mc->current_server == NULL){

1859

if(debug){

1316

1860

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

1317

1861

" No timeout!\n");

1318

1862

}

1319

1863

ret = avahi_simple_poll_iterate(s, -1);

1320

1864

} else {

1321

if (debug){

1865

if(debug){

1322

1866

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

1323

1867

" it, or wait\n");

1324

1868

}

1331

1875

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

1332

1876

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

1333

1877

waited_time.tv_sec = (now.tv_sec

1334

- mc.current_server->last_seen.tv_sec);

1878

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

1335

1879

waited_time.tv_nsec = (now.tv_nsec

1336

- mc.current_server->last_seen.tv_nsec);

1880

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

1337

1881

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

1338

1882

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

1339

1883

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

1341

1885

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

1342

1886

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

1343

1887

1344

if (debug){

1888

if(debug){

1345

1889

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

1346

1890

block_time);

1347

1891

}

1348

1892

1349

1893

if(block_time <= 0){

1350

ret = start_mandos_communication(mc.current_server->ip,

1351

mc.current_server->port,

1352

mc.current_server->if_index,

1353

mc.current_server->af);

1894

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

1895

mc->current_server->port,

1896

mc->current_server->if_index,

1897

mc->current_server->af, mc);

1354

1898

if(ret == 0){

1355

avahi_simple_poll_quit(mc.simple_poll);

1899

avahi_simple_poll_quit(s);

1356

1900

return 0;

1357

1901

}

1358

1902

ret = clock_gettime(CLOCK_MONOTONIC,

1359

&mc.current_server->last_seen);

1903

&mc->current_server->last_seen);

1360

1904

if(ret == -1){

1361

1905

perror_plus("clock_gettime");

1362

1906

return -1;

1363

1907

}

1364

mc.current_server = mc.current_server->next;

1908

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

1365

1909

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

1366

1910

servers, but don't block */

1367

1911

}

1369

1913

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

1370

1914

}

1371

1915

if(ret != 0){

1372

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

1916

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

1373

1917

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

1374

1918

}

1375

1919

}

1376

1920

}

1377

1921

}

1378

1922

1379

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

1923

__attribute__((nonnull))

1924

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

1380

1925

const float delay){

1381

struct dirent **direntries;

1382

struct dirent *direntry;

1383

int ret;

1384

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

1385

alphasort);

1926

struct dirent **direntries = NULL;

1927

if(hookdir_fd == -1){

1928

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1929

| O_CLOEXEC);

1930

if(hookdir_fd == -1){

1931

if(errno == ENOENT){

1932

if(debug){

1933

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

1934

" found\n", hookdir);

1935

}

1936

} else {

1937

perror_plus("open");

1938

}

1939

return;

1940

}

1941

}

1942

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

1943

if(devnull == -1){

1944

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

1945

return;

1946

}

1947

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

1948

runnable_hook, alphasort);

1386

1949

if(numhooks == -1){

1387

1950

perror_plus("scandir");

1388

} else {

1389

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

1390

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

1391

direntry = direntries[0];

1392

char *fullname = NULL;

1393

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

1394

if(ret < 0){

1951

close(devnull);

1952

return;

1953

}

1954

struct dirent *direntry;

1955

int ret;

1956

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

1957

direntry = direntries[i];

1958

if(debug){

1959

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

1960

direntry->d_name);

1961

}

1962

pid_t hook_pid = fork();

1963

if(hook_pid == 0){

1964

/* Child */

1965

/* Raise privileges */

1966

errno = raise_privileges_permanently();

1967

if(errno != 0){

1968

perror_plus("Failed to raise privileges");

1969

_exit(EX_NOPERM);

1970

}

1971

/* Set group */

1972

errno = 0;

1973

ret = setgid(0);

1974

if(ret == -1){

1975

perror_plus("setgid");

1976

_exit(EX_NOPERM);

1977

}

1978

/* Reset supplementary groups */

1979

errno = 0;

1980

ret = setgroups(0, NULL);

1981

if(ret == -1){

1982

perror_plus("setgroups");

1983

_exit(EX_NOPERM);

1984

}

1985

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

1986

if(ret == -1){

1987

perror_plus("setenv");

1988

_exit(EX_OSERR);

1989

}

1990

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

1991

if(ret == -1){

1992

perror_plus("setenv");

1993

_exit(EX_OSERR);

1994

}

1995

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

1996

if(ret == -1){

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

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

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

char *delaystring;

2006

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

2007

if(ret == -1){

1395

2008

perror_plus("asprintf");

1396

continue;

2009

_exit(EX_OSERR);

1397

2010

}

1398

pid_t hook_pid = fork();

1399

if(hook_pid == 0){

1400

/* Child */

1401

dup2(devnull, STDIN_FILENO);

1402

close(devnull);

1403

dup2(STDERR_FILENO, STDOUT_FILENO);

1404

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

1405

if(ret == -1){

1406

perror_plus("setenv");

1407

return false;

1408

}

1409

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

1410

if(ret == -1){

1411

perror_plus("setenv");

1412

return false;

1413

}

1414

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

1415

if(ret == -1){

1416

perror_plus("setenv");

1417

return false;

1418

}

1419

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

1420

if(ret == -1){

1421

perror_plus("setenv");

1422

return false;

1423

}

1424

char *delaystring;

1425

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

1426

if(ret == -1){

1427

perror_plus("asprintf");

1428

return false;

1429

}

1430

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

1431

if(ret == -1){

1432

free(delaystring);

1433

perror_plus("setenv");

1434

return false;

1435

}

2011

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

2012

if(ret == -1){

1436

2013

free(delaystring);

1437

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

1438

perror_plus("execl");

1439

} else {

1440

int status;

1441

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

1442

perror_plus("waitpid");

1443

free(fullname);

1444

continue;

1445

}

1446

if(WIFEXITED(status)){

1447

if(WEXITSTATUS(status) != 0){

1448

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

1449

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

1450

WEXITSTATUS(status));

1451

free(fullname);

1452

continue;

1453

}

1454

} else if(WIFSIGNALED(status)){

1455

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

1456

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

1457

WTERMSIG(status));

1458

free(fullname);

1459

continue;

1460

} else {

1461

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

1462

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

1463

free(fullname);

1464

continue;

1465

}

1466

}

1467

free(fullname);

1468

if(quit_now){

1469

break;

1470

}

1471

}

1472

close(devnull);

1473

}

1474

return true;

2014

perror_plus("setenv");

2015

_exit(EX_OSERR);

2016

}

2017

free(delaystring);

2018

if(connect_to != NULL){

2019

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

2020

if(ret == -1){

2021

perror_plus("setenv");

2022

_exit(EX_OSERR);

2023

}

2024

}

2025

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

2026

direntry->d_name,

2027

O_RDONLY));

2028

if(hook_fd == -1){

2029

perror_plus("openat");

2030

_exit(EXIT_FAILURE);

2031

}

2032

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

2033

perror_plus("close");

2034

_exit(EXIT_FAILURE);

2035

}

2036

ret = dup2(devnull, STDIN_FILENO);

2037

if(ret == -1){

2038

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

2039

_exit(EX_OSERR);

2040

}

2041

ret = close(devnull);

2042

if(ret == -1){

2043

perror_plus("close");

2044

_exit(EX_OSERR);

2045

}

2046

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2047

if(ret == -1){

2048

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

2049

_exit(EX_OSERR);

2050

}

2051

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

2052

environ) == -1){

2053

perror_plus("fexecve");

2054

_exit(EXIT_FAILURE);

2055

}

2056

} else {

2057

if(hook_pid == -1){

2058

perror_plus("fork");

2059

free(direntry);

2060

continue;

2061

}

2062

int status;

2063

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

2064

perror_plus("waitpid");

2065

free(direntry);

2066

continue;

2067

}

2068

if(WIFEXITED(status)){

2069

if(WEXITSTATUS(status) != 0){

2070

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

2071

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

2072

WEXITSTATUS(status));

2073

free(direntry);

2074

continue;

2075

}

2076

} else if(WIFSIGNALED(status)){

2077

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

2078

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

2079

WTERMSIG(status));

2080

free(direntry);

2081

continue;

2082

} else {

2083

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

2084

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

2085

free(direntry);

2086

continue;

2087

}

2088

}

2089

if(debug){

2090

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

2091

direntry->d_name);

2092

}

2093

free(direntry);

2094

}

2095

free(direntries);

2096

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

2097

perror_plus("close");

2098

} else {

2099

hookdir_fd = -1;

2100

}

2101

close(devnull);

2102

}

2103

2104

__attribute__((nonnull, warn_unused_result))

2105

int bring_up_interface(const char *const interface,

2106

const float delay){

2107

int old_errno = errno;

2108

int ret;

2109

struct ifreq network;

2110

unsigned int if_index = if_nametoindex(interface);

2111

if(if_index == 0){

2112

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

2113

errno = old_errno;

2114

return ENXIO;

2115

}

2116

2117

if(quit_now){

2118

errno = old_errno;

2119

return EINTR;

2120

}

2121

2122

if(not interface_is_up(interface)){

2123

int ret_errno = 0;

2124

int ioctl_errno = 0;

2125

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

2126

ret_errno = errno;

2127

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

2128

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

2129

errno = old_errno;

2130

return ret_errno;

2131

}

2132

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

2133

2134

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

2135

if(sd == -1){

2136

ret_errno = errno;

2137

perror_plus("socket");

2138

errno = old_errno;

2139

return ret_errno;

2140

}

2141

2142

if(quit_now){

2143

ret = close(sd);

2144

if(ret == -1){

2145

perror_plus("close");

2146

}

2147

errno = old_errno;

2148

return EINTR;

2149

}

2150

2151

if(debug){

2152

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

2153

interface);

2154

}

2155

2156

/* Raise privileges */

2157

ret_errno = raise_privileges();

2158

if(ret_errno != 0){

2159

errno = ret_errno;

2160

perror_plus("Failed to raise privileges");

2161

}

2162

2163

#ifdef __linux__

2164

int ret_linux;

2165

bool restore_loglevel = false;

2166

if(ret_errno == 0){

2167

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2168

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

2169

ret_linux = klogctl(8, NULL, 5);

2170

if(ret_linux == -1){

2171

perror_plus("klogctl");

2172

} else {

2173

restore_loglevel = true;

2174

}

2175

}

2176

#endif /* __linux__ */

2177

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

2178

ioctl_errno = errno;

2179

#ifdef __linux__

2180

if(restore_loglevel){

2181

ret_linux = klogctl(7, NULL, 0);

2182

if(ret_linux == -1){

2183

perror_plus("klogctl");

2184

}

2185

}

2186

#endif /* __linux__ */

2187

2188

/* If raise_privileges() succeeded above */

2189

if(ret_errno == 0){

2190

/* Lower privileges */

2191

ret_errno = lower_privileges();

2192

if(ret_errno != 0){

2193

errno = ret_errno;

2194

perror_plus("Failed to lower privileges");

2195

}

2196

}

2197

2198

/* Close the socket */

2199

ret = close(sd);

2200

if(ret == -1){

2201

perror_plus("close");

2202

}

2203

2204

if(ret_setflags == -1){

2205

errno = ioctl_errno;

2206

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2207

errno = old_errno;

2208

return ioctl_errno;

2209

}

2210

} else if(debug){

2211

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

2212

interface);

2213

}

2214

2215

/* Sleep checking until interface is running.

2216

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

2217

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

2218

if(interface_is_running(interface)){

2219

break;

2220

}

2221

struct timespec sleeptime = { .tv_nsec = 250000000 };

2222

ret = nanosleep(&sleeptime, NULL);

2223

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

2224

perror_plus("nanosleep");

2225

}

2226

}

2227

2228

errno = old_errno;

2229

return 0;

2230

}

2231

2232

__attribute__((nonnull, warn_unused_result))

2233

int take_down_interface(const char *const interface){

2234

int old_errno = errno;

2235

struct ifreq network;

2236

unsigned int if_index = if_nametoindex(interface);

2237

if(if_index == 0){

2238

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

2239

errno = old_errno;

2240

return ENXIO;

2241

}

2242

if(interface_is_up(interface)){

2243

int ret_errno = 0;

2244

int ioctl_errno = 0;

2245

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

2246

ret_errno = errno;

2247

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

2248

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

2249

errno = old_errno;

2250

return ret_errno;

2251

}

2252

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

2253

2254

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

2255

if(sd == -1){

2256

ret_errno = errno;

2257

perror_plus("socket");

2258

errno = old_errno;

2259

return ret_errno;

2260

}

2261

2262

if(debug){

2263

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

2264

interface);

2265

}

2266

2267

/* Raise privileges */

2268

ret_errno = raise_privileges();

2269

if(ret_errno != 0){

2270

errno = ret_errno;

2271

perror_plus("Failed to raise privileges");

2272

}

2273

2274

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

2275

ioctl_errno = errno;

2276

2277

/* If raise_privileges() succeeded above */

2278

if(ret_errno == 0){

2279

/* Lower privileges */

2280

ret_errno = lower_privileges();

2281

if(ret_errno != 0){

2282

errno = ret_errno;

2283

perror_plus("Failed to lower privileges");

2284

}

2285

}

2286

2287

/* Close the socket */

2288

int ret = close(sd);

2289

if(ret == -1){

2290

perror_plus("close");

2291

}

2292

2293

if(ret_setflags == -1){

2294

errno = ioctl_errno;

2295

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2296

errno = old_errno;

2297

return ioctl_errno;

2298

}

2299

} else if(debug){

2300

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

2301

interface);

2302

}

2303

2304

errno = old_errno;

2305

return 0;

1475

2306

}

1476

2307

1477

2308

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

2309

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

2310

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

2311

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

2312

.current_server = NULL, .interfaces = NULL,

2313

.interfaces_size = 0 };

1478

2314

AvahiSServiceBrowser *sb = NULL;

1479

int error;

2315

error_t ret_errno;

1480

2316

int ret;

1481

2317

intmax_t tmpmax;

1482

2318

char *tmp;

1483

2319

int exitcode = EXIT_SUCCESS;

1484

const char *interface = "";

1485

struct ifreq network;

1486

int sd = -1;

1487

bool take_down_interface = false;

1488

uid_t uid;

1489

gid_t gid;

1490

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

1491

bool tempdir_created = false;

2320

char *interfaces_to_take_down = NULL;

2321

size_t interfaces_to_take_down_size = 0;

2322

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

2323

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

2324

char *tempdir = NULL;

1492

2325

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1493

2326

const char *seckey = PATHDIR "/" SECKEY;

1494

2327

const char *pubkey = PATHDIR "/" PUBKEY;

2328

const char *dh_params_file = NULL;

2329

char *interfaces_hooks = NULL;

1495

2330

1496

2331

bool gnutls_initialized = false;

1497

2332

bool gpgme_initialized = false;

1549

2384

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

1550

2385

" Diffie-Hellman key exchange",

1551

2386

.group = 2 },

2387

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

2388

.arg = "FILE",

2389

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

2390

" for the Diffie-Hellman key exchange",

2391

.group = 2 },

1552

2392

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

1553

2393

.arg = "STRING",

1554

2394

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

1559

2399

.group = 2 },

1560

2400

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

1561

2401

.arg = "SECONDS",

1562

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

2402

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

1563

2403

.group = 2 },

1564

2404

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

1565

2405

.arg = "DIR",

1588

2428

connect_to = arg;

1589

2429

break;

1590

2430

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

1591

interface = arg;

2431

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

2432

arg, (int)',');

2433

if(ret_errno != 0){

2434

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

2435

}

1592

2436

break;

1593

2437

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

1594

2438

seckey = arg;

1605

2449

}

1606

2450

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

1607

2451

break;

2452

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

2453

dh_params_file = arg;

2454

break;

1608

2455

case 130: /* --priority */

1609

2456

mc.priority = arg;

1610

2457

break;

1637

2484

argp_state_help(state, state->out_stream,

1638

2485

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1639

2486

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

1640

fprintf_plus(state->out_stream,

1641

"Mandos plugin mandos-client: ");

1642

2487

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

1643

2488

exit(argp_err_exit_status);

1644

2489

break;

1652

2497

.args_doc = "",

1653

2498

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

1654

2499

" passwords from a Mandos server" };

1655

ret = argp_parse(&argp, argc, argv,

1656

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1657

switch(ret){

2500

ret_errno = argp_parse(&argp, argc, argv,

2501

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2502

switch(ret_errno){

1658

2503

case 0:

1659

2504

break;

1660

2505

case ENOMEM:

1661

2506

default:

1662

errno = ret;

2507

errno = ret_errno;

1663

2508

perror_plus("argp_parse");

1664

2509

exitcode = EX_OSERR;

1665

2510

goto end;

1668

2513

goto end;

1669

2514

}

1670

2515

}

1671

2516

1672

2517

{

1673

2518

/* Work around Debian bug #633582:

1674

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

1675

struct stat st;

1676

1677

/* Re-raise priviliges */

1678

errno = 0;

1679

ret = seteuid(0);

1680

if(ret == -1){

1681

perror_plus("seteuid");

1682

}

1683

1684

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

1685

int seckey_fd = open(seckey, O_RDONLY);

1686

if(seckey_fd == -1){

1687

perror_plus("open");

1688

} else {

1689

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

1690

if(ret == -1){

1691

perror_plus("fstat");

1692

} else {

1693

if(S_ISREG(st.st_mode)

1694

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

1695

ret = fchown(seckey_fd, uid, gid);

1696

if(ret == -1){

1697

perror_plus("fchown");

1698

}

1699

}

1700

}

1701

TEMP_FAILURE_RETRY(close(seckey_fd));

1702

}

1703

}

1704

1705

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

1706

int pubkey_fd = open(pubkey, O_RDONLY);

1707

if(pubkey_fd == -1){

1708

perror_plus("open");

1709

} else {

1710

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

1711

if(ret == -1){

1712

perror_plus("fstat");

1713

} else {

1714

if(S_ISREG(st.st_mode)

1715

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

1716

ret = fchown(pubkey_fd, uid, gid);

1717

if(ret == -1){

1718

perror_plus("fchown");

1719

}

1720

}

1721

}

1722

TEMP_FAILURE_RETRY(close(pubkey_fd));

1723

}

1724

}

1725

1726

/* Lower privileges */

1727

errno = 0;

1728

ret = seteuid(uid);

1729

if(ret == -1){

1730

perror_plus("seteuid");

2519

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

2520

2521

/* Re-raise privileges */

2522

ret = raise_privileges();

2523

if(ret != 0){

2524

errno = ret;

2525

perror_plus("Failed to raise privileges");

2526

} else {

2527

struct stat st;

2528

2529

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

2530

int seckey_fd = open(seckey, O_RDONLY);

2531

if(seckey_fd == -1){

2532

perror_plus("open");

2533

} else {

2534

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

2535

if(ret == -1){

2536

perror_plus("fstat");

2537

} else {

2538

if(S_ISREG(st.st_mode)

2539

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

2540

ret = fchown(seckey_fd, uid, gid);

2541

if(ret == -1){

2542

perror_plus("fchown");

2543

}

2544

}

2545

}

2546

close(seckey_fd);

2547

}

2548

}

2549

2550

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

2551

int pubkey_fd = open(pubkey, O_RDONLY);

2552

if(pubkey_fd == -1){

2553

perror_plus("open");

2554

} else {

2555

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

2556

if(ret == -1){

2557

perror_plus("fstat");

2558

} else {

2559

if(S_ISREG(st.st_mode)

2560

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

2561

ret = fchown(pubkey_fd, uid, gid);

2562

if(ret == -1){

2563

perror_plus("fchown");

2564

}

2565

}

2566

}

2567

close(pubkey_fd);

2568

}

2569

}

2570

2571

if(dh_params_file != NULL

2572

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

2573

int dhparams_fd = open(dh_params_file, O_RDONLY);

2574

if(dhparams_fd == -1){

2575

perror_plus("open");

2576

} else {

2577

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

2578

if(ret == -1){

2579

perror_plus("fstat");

2580

} else {

2581

if(S_ISREG(st.st_mode)

2582

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

2583

ret = fchown(dhparams_fd, uid, gid);

2584

if(ret == -1){

2585

perror_plus("fchown");

2586

}

2587

}

2588

}

2589

close(dhparams_fd);

2590

}

2591

}

2592

2593

/* Lower privileges */

2594

ret = lower_privileges();

2595

if(ret != 0){

2596

errno = ret;

2597

perror_plus("Failed to lower privileges");

2598

}

2599

}

2600

}

2601

2602

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

2603

{

2604

char *interface = NULL;

2605

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

2606

interface))){

2607

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

2608

and if_nametoindex(interface) == 0){

2609

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

2610

fprintf_plus(stderr, "Not using nonexisting interface"

2611

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

2612

}

2613

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

2614

interface = NULL;

2615

}

1731

2616

}

1732

2617

}

1733

2618

1734

2619

/* Run network hooks */

1735

2620

{

1736

/* Re-raise priviliges */

1737

errno = 0;

1738

ret = seteuid(0);

1739

if(ret == -1){

1740

perror_plus("seteuid");

1741

}

1742

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

1743

goto end;

1744

}

1745

/* Lower privileges */

1746

errno = 0;

1747

ret = seteuid(uid);

1748

if(ret == -1){

1749

perror_plus("seteuid");

1750

}

2621

if(mc.interfaces != NULL){

2622

interfaces_hooks = malloc(mc.interfaces_size);

2623

if(interfaces_hooks == NULL){

2624

perror_plus("malloc");

2625

goto end;

2626

}

2627

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

2628

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

2629

}

2630

run_network_hooks("start", interfaces_hooks != NULL ?

2631

interfaces_hooks : "", delay);

1751

2632

}

1752

2633

1753

2634

if(not debug){

1754

2635

avahi_set_log_function(empty_log);

1755

2636

}

1756

2637

1757

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

1758

struct dirent **direntries;

1759

/* First look for interfaces that are up */

1760

ret = scandir(sys_class_net, &direntries, up_interface,

1761

alphasort);

1762

if(ret == 0){

1763

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

1764

free(direntries);

1765

ret = scandir(sys_class_net, &direntries, good_interface,

1766

alphasort);

1767

}

1768

if(ret >= 1){

1769

/* Pick the first interface returned */

1770

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

1771

if(debug){

1772

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

1773

}

1774

if(interface == NULL){

1775

perror_plus("malloc");

1776

free(direntries);

1777

exitcode = EXIT_FAILURE;

1778

goto end;

1779

}

1780

free(direntries);

1781

} else {

1782

free(direntries);

1783

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

1784

exitcode = EXIT_FAILURE;

1785

goto end;

1786

}

1787

}

1788

1789

2638

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

1790

2639

from the signal handler */

1791

2640

/* Initialize the pseudo-RNG for Avahi */

1792

2641

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

1793

mc.simple_poll = avahi_simple_poll_new();

1794

if(mc.simple_poll == NULL){

2642

simple_poll = avahi_simple_poll_new();

2643

if(simple_poll == NULL){

1795

2644

fprintf_plus(stderr,

1796

2645

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

1797

2646

exitcode = EX_UNAVAILABLE;

1861

2710

}

1862

2711

}

1863

2712

1864

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

1865

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

1866

if_index = (AvahiIfIndex) if_nametoindex(interface);

1867

if(if_index == 0){

1868

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

1869

exitcode = EX_UNAVAILABLE;

1870

goto end;

1871

}

1872

1873

if(quit_now){

1874

goto end;

1875

}

1876

1877

/* Re-raise priviliges */

1878

errno = 0;

1879

ret = seteuid(0);

1880

if(ret == -1){

1881

perror_plus("seteuid");

1882

}

1883

1884

#ifdef __linux__

1885

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1886

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

1887

ret = klogctl(8, NULL, 5);

1888

bool restore_loglevel = true;

1889

if(ret == -1){

1890

restore_loglevel = false;

1891

perror_plus("klogctl");

1892

}

1893

#endif /* __linux__ */

1894

1895

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1896

if(sd < 0){

1897

perror_plus("socket");

1898

exitcode = EX_OSERR;

1899

#ifdef __linux__

1900

if(restore_loglevel){

1901

ret = klogctl(7, NULL, 0);

1902

if(ret == -1){

1903

perror_plus("klogctl");

1904

}

1905

}

1906

#endif /* __linux__ */

1907

/* Lower privileges */

1908

errno = 0;

1909

ret = seteuid(uid);

1910

if(ret == -1){

1911

perror_plus("seteuid");

1912

}

1913

goto end;

1914

}

1915

strcpy(network.ifr_name, interface);

1916

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

1917

if(ret == -1){

1918

perror_plus("ioctl SIOCGIFFLAGS");

1919

#ifdef __linux__

1920

if(restore_loglevel){

1921

ret = klogctl(7, NULL, 0);

1922

if(ret == -1){

1923

perror_plus("klogctl");

1924

}

1925

}

1926

#endif /* __linux__ */

1927

exitcode = EX_OSERR;

1928

/* Lower privileges */

1929

errno = 0;

1930

ret = seteuid(uid);

1931

if(ret == -1){

1932

perror_plus("seteuid");

1933

}

1934

goto end;

1935

}

1936

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

1937

network.ifr_flags |= IFF_UP;

1938

take_down_interface = true;

1939

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

1940

if(ret == -1){

1941

take_down_interface = false;

1942

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1943

exitcode = EX_OSERR;

1944

#ifdef __linux__

1945

if(restore_loglevel){

1946

ret = klogctl(7, NULL, 0);

1947

if(ret == -1){

1948

perror_plus("klogctl");

2713

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

2714

if(mc.interfaces == NULL){

2715

struct dirent **direntries = NULL;

2716

/* Look for any good interfaces */

2717

ret = scandir(sys_class_net, &direntries, good_interface,

2718

alphasort);

2719

if(ret >= 1){

2720

/* Add all found interfaces to interfaces list */

2721

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

2722

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

2723

direntries[i]->d_name);

2724

if(ret_errno != 0){

2725

errno = ret_errno;

2726

perror_plus("argz_add");

2727

free(direntries[i]);

2728

continue;

2729

}

2730

if(debug){

2731

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

2732

direntries[i]->d_name);

2733

}

2734

free(direntries[i]);

2735

}

2736

free(direntries);

2737

} else {

2738

if(ret == 0){

2739

free(direntries);

2740

}

2741

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

2742

exitcode = EXIT_FAILURE;

2743

goto end;

2744

}

2745

}

2746

2747

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

2748

{

2749

char *interface = NULL;

2750

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

2751

interface))){

2752

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

2753

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

2754

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

2755

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

2756

interface);

2757

interface = NULL;

2758

while((interface = argz_next(mc.interfaces,

2759

mc.interfaces_size, interface))){

2760

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

2761

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

2762

interface);

2763

interface = NULL;

1949

2764

}

1950

2765

}

1951

#endif /* __linux__ */

1952

/* Lower privileges */

1953

errno = 0;

1954

ret = seteuid(uid);

1955

if(ret == -1){

1956

perror_plus("seteuid");

1957

}

1958

goto end;

1959

}

1960

}

1961

/* Sleep checking until interface is running.

1962

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

1963

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

1964

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

1965

if(ret == -1){

1966

perror_plus("ioctl SIOCGIFFLAGS");

1967

} else if(network.ifr_flags & IFF_RUNNING){

1968

2766

break;

1969

2767

}

1970

struct timespec sleeptime = { .tv_nsec = 250000000 };

1971

ret = nanosleep(&sleeptime, NULL);

1972

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

1973

perror_plus("nanosleep");

1974

}

1975

}

1976

if(not take_down_interface){

1977

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

1978

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

1979

if(ret == -1){

1980

perror_plus("close");

1981

}

1982

}

1983

#ifdef __linux__

1984

if(restore_loglevel){

1985

/* Restores kernel loglevel to default */

1986

ret = klogctl(7, NULL, 0);

1987

if(ret == -1){

1988

perror_plus("klogctl");

1989

}

1990

}

1991

#endif /* __linux__ */

1992

/* Lower privileges */

1993

errno = 0;

1994

/* Lower privileges */

1995

ret = seteuid(uid);

1996

if(ret == -1){

1997

perror_plus("seteuid");

1998

}

2768

bool interface_was_up = interface_is_up(interface);

2769

errno = bring_up_interface(interface, delay);

2770

if(not interface_was_up){

2771

if(errno != 0){

2772

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

2773

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

2774

} else {

2775

errno = argz_add(&interfaces_to_take_down,

2776

&interfaces_to_take_down_size,

2777

interface);

2778

if(errno != 0){

2779

perror_plus("argz_add");

2780

}

2781

}

2782

}

2783

}

2784

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

2785

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

2786

}

2787

}

2788

2789

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

2790

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

2791

if(debug){

2792

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

2793

mc.interfaces);

2794

}

2795

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

1999

2796

}

2000

2797

2001

2798

if(quit_now){

2002

2799

goto end;

2003

2800

}

2004

2801

2005

ret = init_gnutls_global(pubkey, seckey);

2802

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

2006

2803

if(ret == -1){

2007

2804

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

2008

2805

exitcode = EX_UNAVAILABLE;

2015

2812

goto end;

2016

2813

}

2017

2814

2018

if(mkdtemp(tempdir) == NULL){

2815

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

2816

tempdir = mkdtemp(run_tempdir);

2817

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

2818

if(debug){

2819

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

2820

run_tempdir, old_tempdir);

2821

}

2822

tempdir = mkdtemp(old_tempdir);

2823

}

2824

if(tempdir == NULL){

2019

2825

perror_plus("mkdtemp");

2020

2826

goto end;

2021

2827

}

2022

tempdir_created = true;

2023

2828

2024

2829

if(quit_now){

2025

2830

goto end;

2026

2831

}

2027

2832

2028

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

2833

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

2029

2834

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

2030

2835

exitcode = EX_UNAVAILABLE;

2031

2836

goto end;

2041

2846

/* Connect directly, do not use Zeroconf */

2042

2847

/* (Mainly meant for debugging) */

2043

2848

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

2849

2044

2850

if(address == NULL){

2045

2851

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

2046

2852

exitcode = EX_USAGE;

2051

2857

goto end;

2052

2858

}

2053

2859

2054

uint16_t port;

2860

in_port_t port;

2055

2861

errno = 0;

2056

2862

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

2057

2863

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

2058

or tmpmax != (uint16_t)tmpmax){

2864

or tmpmax != (in_port_t)tmpmax){

2059

2865

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

2060

2866

exitcode = EX_USAGE;

2061

2867

goto end;

2062

2868

}

2063

2869

2064

2870

if(quit_now){

2065

2871

goto end;

2066

2872

}

2067

2873

2068

port = (uint16_t)tmpmax;

2874

port = (in_port_t)tmpmax;

2069

2875

*address = '\0';

2070

2876

/* Colon in address indicates IPv6 */

2071

2877

int af;

2087

2893

}

2088

2894

2089

2895

while(not quit_now){

2090

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

2896

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

2897

&mc);

2091

2898

if(quit_now or ret == 0){

2092

2899

break;

2093

2900

}

2095

2902

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

2096

2903

(int)retry_interval);

2097

2904

}

2098

sleep((int)retry_interval);

2905

sleep((unsigned int)retry_interval);

2099

2906

}

2100

2907

2101

if (not quit_now){

2908

if(not quit_now){

2102

2909

exitcode = EXIT_SUCCESS;

2103

2910

}

2104

2911

2119

2926

config.publish_domain = 0;

2120

2927

2121

2928

/* Allocate a new server */

2122

mc.server = avahi_server_new(avahi_simple_poll_get

2123

(mc.simple_poll), &config, NULL,

2124

NULL, &error);

2929

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2930

&config, NULL, NULL, &ret);

2125

2931

2126

2932

/* Free the Avahi configuration data */

2127

2933

avahi_server_config_free(&config);

2130

2936

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

2131

2937

if(mc.server == NULL){

2132

2938

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

2133

avahi_strerror(error));

2939

avahi_strerror(ret));

2134

2940

exitcode = EX_UNAVAILABLE;

2135

2941

goto end;

2136

2942

}

2142

2948

/* Create the Avahi service browser */

2143

2949

sb = avahi_s_service_browser_new(mc.server, if_index,

2144

2950

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2145

NULL, 0, browse_callback, NULL);

2951

NULL, 0, browse_callback,

2952

(void *)&mc);

2146

2953

if(sb == NULL){

2147

2954

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

2148

2955

avahi_strerror(avahi_server_errno(mc.server)));

2159

2966

if(debug){

2160

2967

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

2161

2968

}

2162

2163

ret = avahi_loop_with_timeout(mc.simple_poll,

2164

(int)(retry_interval * 1000));

2969

2970

ret = avahi_loop_with_timeout(simple_poll,

2971

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

2165

2972

if(debug){

2166

2973

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

2167

2974

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

2170

2977

end:

2171

2978

2172

2979

if(debug){

2173

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

2980

if(signal_received){

2981

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

2982

argv[0], signal_received,

2983

strsignal(signal_received));

2984

} else {

2985

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

2986

}

2174

2987

}

2175

2988

2176

2989

/* Cleanup things */

2990

free(mc.interfaces);

2991

2177

2992

if(sb != NULL)

2178

2993

avahi_s_service_browser_free(sb);

2179

2994

2180

2995

if(mc.server != NULL)

2181

2996

avahi_server_free(mc.server);

2182

2997

2183

if(mc.simple_poll != NULL)

2184

avahi_simple_poll_free(mc.simple_poll);

2998

if(simple_poll != NULL)

2999

avahi_simple_poll_free(simple_poll);

2185

3000

2186

3001

if(gnutls_initialized){

2187

3002

gnutls_certificate_free_credentials(mc.cred);

2188

gnutls_global_deinit();

2189

3003

gnutls_dh_params_deinit(mc.dh_params);

2190

3004

}

2191

3005

2192

3006

if(gpgme_initialized){

2193

3007

gpgme_release(mc.ctx);

2194

3008

}

2195

3009

2196

3010

/* Cleans up the circular linked list of Mandos servers the client

2197

3011

has seen */

2198

3012

if(mc.current_server != NULL){

2199

3013

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

2200

3014

while(mc.current_server != NULL){

2201

3015

server *next = mc.current_server->next;

3016

#ifdef __GNUC__

3017

#pragma GCC diagnostic push

3018

#pragma GCC diagnostic ignored "-Wcast-qual"

3019

#endif

3020

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

3021

#ifdef __GNUC__

3022

#pragma GCC diagnostic pop

3023

#endif

2202

3024

free(mc.current_server);

2203

3025

mc.current_server = next;

2204

3026

}

2205

3027

}

2206

3028

2207

/* Re-raise priviliges */

3029

/* Re-raise privileges */

2208

3030

{

2209

errno = 0;

2210

ret = seteuid(0);

2211

if(ret == -1){

2212

perror_plus("seteuid");

2213

}

2214

/* Run network hooks */

2215

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

2216

goto end;

3031

ret = raise_privileges();

3032

if(ret != 0){

3033

errno = ret;

3034

perror_plus("Failed to raise privileges");

3035

} else {

3036

3037

/* Run network hooks */

3038

run_network_hooks("stop", interfaces_hooks != NULL ?

3039

interfaces_hooks : "", delay);

3040

3041

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

3042

{

3043

char *interface = NULL;

3044

while((interface = argz_next(interfaces_to_take_down,

3045

interfaces_to_take_down_size,

3046

interface))){

3047

ret = take_down_interface(interface);

3048

if(ret != 0){

3049

errno = ret;

3050

perror_plus("Failed to take down interface");

3051

}

3052

}

3053

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

3054

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

3055

" down\n");

3056

}

3057

}

2217

3058

}

2218

3059

2219

/* Take down the network interface */

2220

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

2221

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

2222

if(ret == -1){

2223

perror_plus("ioctl SIOCGIFFLAGS");

2224

} else if(network.ifr_flags & IFF_UP){

2225

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

2226

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

2227

if(ret == -1){

2228

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2229

}

2230

}

2231

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

2232

if(ret == -1){

2233

perror_plus("close");

2234

}

3060

ret = lower_privileges_permanently();

3061

if(ret != 0){

3062

errno = ret;

3063

perror_plus("Failed to lower privileges permanently");

2235

3064

}

2236

3065

}

2237

/* Lower privileges permanently */

2238

errno = 0;

2239

ret = setuid(uid);

2240

if(ret == -1){

2241

perror_plus("setuid");

3066

3067

free(interfaces_to_take_down);

3068

free(interfaces_hooks);

3069

3070

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

3071

uintmax_t level){

3072

struct dirent **direntries = NULL;

3073

int dret;

3074

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

3075

O_RDONLY

3076

| O_NOFOLLOW

3077

| O_DIRECTORY

3078

| O_PATH));

3079

if(dir_fd == -1){

3080

perror_plus("open");

3081

return;

3082

}

3083

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

3084

notdotentries, alphasort);

3085

if(numentries >= 0){

3086

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

3087

if(debug){

3088

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

3089

dirname, direntries[i]->d_name);

3090

}

3091

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

3092

if(dret == -1){

3093

if(errno == EISDIR){

3094

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

3095

AT_REMOVEDIR);

3096

}

3097

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

3098

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

3099

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

3100

/* Recurse only in this special case */

3101

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

3102

dret = 0;

3103

}

3104

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

3105

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

3106

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

3107

}

3108

}

3109

free(direntries[i]);

3110

}

3111

3112

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

3113

free(direntries);

3114

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3115

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

3116

perror_plus("rmdir");

3117

}

3118

} else {

3119

perror_plus("scandirat");

3120

}

3121

close(dir_fd);

2242

3122

}

2243

3123

2244

3124

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

2245

if(tempdir_created){

2246

struct dirent **direntries = NULL;

2247

struct dirent *direntry = NULL;

2248

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

2249

alphasort);

2250

if (numentries > 0){

2251

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

2252

direntry = direntries[i];

2253

char *fullname = NULL;

2254

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

2255

direntry->d_name);

2256

if(ret < 0){

2257

perror_plus("asprintf");

2258

continue;

2259

}

2260

ret = remove(fullname);

2261

if(ret == -1){

2262

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

2263

strerror(errno));

2264

}

2265

free(fullname);

2266

}

2267

}

2268

2269

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

2270

free(direntries);

2271

if (numentries == -1){

2272

perror_plus("scandir");

2273

}

2274

ret = rmdir(tempdir);

2275

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

2276

perror_plus("rmdir");

2277

}

3125

if(tempdir != NULL){

3126

clean_dir_at(-1, tempdir, 0);

2278

3127

}

2279

3128

2280

3129

if(quit_now){