/mandos/trunk : revision 237.4.98

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

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*

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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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*

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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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* 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

*/

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

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

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stdout, ferror(), remove() */

44

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

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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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strtof(), abort() */

48

49

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

49

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

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

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

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asprintf(), strncpy(), strsignal()

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*/

51

53

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

52

54

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

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55

sockaddr_in6, PF_INET6,

55

57

opendir(), DIR */

56

58

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

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59

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

58

inet_pton(), connect() */

59

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

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inet_pton(), connect(),

61

getnameinfo() */

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

60

63

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

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64

*/

62

65

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

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66

strtoimax() */

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

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

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

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72

program_invocation_short_name */

67

73

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

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

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79

*/

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80

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

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81

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

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

77

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

82

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

83

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,

88

95

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

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96

WEXITSTATUS(), WTERMSIG() */

90

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() */

91

104

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105

#ifdef __linux__

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106

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

135

148

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

136

149

char *connect_to = NULL;

137

150

const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

152

uid_t uid = 65534;

153

gid_t gid = 65534;

138

154

139

155

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

140

156

typedef struct server{

141

157

const char *ip;

142

uint16_t port;

158

in_port_t port;

143

159

AvahiIfIndex if_index;

144

160

int af;

145

161

struct timespec last_seen;

149

165

150

166

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

151

167

typedef struct {

152

AvahiSimplePoll *simple_poll;

153

168

AvahiServer *server;

154

169

gnutls_certificate_credentials_t cred;

155

170

unsigned int dh_bits;

157

172

const char *priority;

158

173

gpgme_ctx_t ctx;

159

174

server *current_server;

175

char *interfaces;

176

size_t interfaces_size;

160

177

} mandos_context;

161

178

162

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

163

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

164

.dh_bits = 1024, .priority = "SECURE256"

165

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

166

.current_server = NULL };

179

/* global so signal handler can reach it*/

180

AvahiSimplePoll *simple_poll;

167

181

168

182

sig_atomic_t quit_now = 0;

169

183

int signal_received = 0;

177

191

perror(print_text);

178

192

}

179

193

180

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

194

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

181

195

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

182

196

va_list ap;

183

197

va_start (ap, format);

184

198

185

199

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

186

200

program_invocation_short_name));

187

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

201

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

188

202

}

189

203

190

204

/*

192

206

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

193

207

* "buffer_length" is how much is already used.

194

208

*/

209

__attribute__((nonnull, warn_unused_result))

195

210

size_t incbuffer(char **buffer, size_t buffer_length,

196

211

size_t buffer_capacity){

197

212

if(buffer_length + BUFFER_SIZE > buffer_capacity){

198

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

199

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;

200

219

return 0;

201

220

}

221

*buffer = new_buf;

202

222

buffer_capacity += BUFFER_SIZE;

203

223

}

204

224

return buffer_capacity;

205

225

}

206

226

207

227

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

208

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

209

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){

210

231

int ret;

211

232

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

212

233

if(new_server == NULL){

219

240

.af = af };

220

241

if(new_server->ip == NULL){

221

242

perror_plus("strdup");

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);

222

258

return false;

223

259

}

224

260

/* Special case of first server */

225

if (mc.current_server == NULL){

261

if(*current_server == NULL){

226

262

new_server->next = new_server;

227

263

new_server->prev = new_server;

228

mc.current_server = new_server;

229

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

264

*current_server = new_server;

230

265

} else {

231

new_server->next = mc.current_server;

232

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;

233

269

new_server->prev->next = new_server;

234

mc.current_server->prev = new_server;

235

}

236

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

237

if(ret == -1){

238

perror_plus("clock_gettime");

239

return false;

270

(*current_server)->prev = new_server;

240

271

}

241

272

return true;

242

273

}

244

275

/*

245

276

* Initialize GPGME.

246

277

*/

247

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

248

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){

249

283

gpgme_error_t rc;

250

284

gpgme_engine_info_t engine_info;

251

285

252

253

286

/*

254

287

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

255

288

*/

256

bool import_key(const char *filename){

289

bool import_key(const char * const filename){

257

290

int ret;

258

291

int fd;

259

292

gpgme_data_t pgp_data;

271

304

return false;

272

305

}

273

306

274

rc = gpgme_op_import(mc.ctx, pgp_data);

307

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

275

308

if(rc != GPG_ERR_NO_ERROR){

276

309

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

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310

gpgme_strsource(rc), gpgme_strerror(rc));

278

311

return false;

279

312

}

280

313

281

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

314

ret = close(fd);

282

315

if(ret == -1){

283

316

perror_plus("close");

284

317

}

321

354

}

322

355

323

356

/* Create new GPGME "context" */

324

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

357

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

325

358

if(rc != GPG_ERR_NO_ERROR){

326

359

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

327

360

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

340

373

* Decrypt OpenPGP data.

341

374

* Returns -1 on error

342

375

*/

376

__attribute__((nonnull, warn_unused_result))

343

377

static ssize_t pgp_packet_decrypt(const char *cryptotext,

344

378

size_t crypto_size,

345

char **plaintext){

379

char **plaintext,

380

mandos_context *mc){

346

381

gpgme_data_t dh_crypto, dh_plain;

347

382

gpgme_error_t rc;

348

383

ssize_t ret;

374

409

375

410

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

376

411

data buffer */

377

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

412

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

378

413

if(rc != GPG_ERR_NO_ERROR){

379

414

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

380

415

gpgme_strsource(rc), gpgme_strerror(rc));

381

416

plaintext_length = -1;

382

417

if(debug){

383

418

gpgme_decrypt_result_t result;

384

result = gpgme_op_decrypt_result(mc.ctx);

419

result = gpgme_op_decrypt_result(mc->ctx);

385

420

if(result == NULL){

386

421

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

387

422

} else {

464

499

return plaintext_length;

465

500

}

466

501

467

static const char * safer_gnutls_strerror(int value){

468

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

469

-Wunreachable-code */

470

if(ret == NULL)

471

ret = "(unknown)";

472

return ret;

502

__attribute__((warn_unused_result, const))

503

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

504

if(str == NULL)

505

return "(unknown)";

506

return str;

507

}

508

509

__attribute__((warn_unused_result))

510

static const char *safer_gnutls_strerror(int value){

511

const char *ret = gnutls_strerror(value);

512

return safe_string(ret);

473

513

}

474

514

475

515

/* GnuTLS log function callback */

516

__attribute__((nonnull))

476

517

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

477

518

const char* string){

478

519

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

479

520

}

480

521

522

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

481

523

static int init_gnutls_global(const char *pubkeyfilename,

482

const char *seckeyfilename){

524

const char *seckeyfilename,

525

const char *dhparamsfilename,

526

mandos_context *mc){

483

527

int ret;

528

unsigned int uret;

484

529

485

530

if(debug){

486

531

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

487

532

}

488

533

489

ret = gnutls_global_init();

490

if(ret != GNUTLS_E_SUCCESS){

491

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

492

safer_gnutls_strerror(ret));

493

return -1;

494

}

495

496

534

if(debug){

497

535

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

498

536

* - GnuTLS manual

502

540

}

503

541

504

542

/* OpenPGP credentials */

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

506

544

if(ret != GNUTLS_E_SUCCESS){

507

545

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

508

546

safer_gnutls_strerror(ret));

509

gnutls_global_deinit();

510

547

return -1;

511

548

}

512

549

518

555

}

519

556

520

557

ret = gnutls_certificate_set_openpgp_key_file

521

(mc.cred, pubkeyfilename, seckeyfilename,

558

(mc->cred, pubkeyfilename, seckeyfilename,

522

559

GNUTLS_OPENPGP_FMT_BASE64);

523

560

if(ret != GNUTLS_E_SUCCESS){

524

561

fprintf_plus(stderr,

530

567

}

531

568

532

569

/* GnuTLS server initialization */

533

ret = gnutls_dh_params_init(&mc.dh_params);

570

ret = gnutls_dh_params_init(&mc->dh_params);

534

571

if(ret != GNUTLS_E_SUCCESS){

535

572

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

536

573

" initialization: %s\n",

537

574

safer_gnutls_strerror(ret));

538

575

goto globalfail;

539

576

}

540

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

541

if(ret != GNUTLS_E_SUCCESS){

542

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

543

safer_gnutls_strerror(ret));

544

goto globalfail;

545

}

546

547

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

577

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

578

if(dhparamsfilename != NULL){

579

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

580

do {

581

int dhpfile = open(dhparamsfilename, O_RDONLY);

582

if(dhpfile == -1){

583

perror_plus("open");

584

dhparamsfilename = NULL;

585

break;

586

}

587

size_t params_capacity = 0;

588

while(true){

589

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

590

(size_t)params.size,

591

(size_t)params_capacity);

592

if(params_capacity == 0){

593

perror_plus("incbuffer");

594

free(params.data);

595

params.data = NULL;

596

dhparamsfilename = NULL;

597

break;

598

}

599

ssize_t bytes_read = read(dhpfile,

600

params.data + params.size,

601

BUFFER_SIZE);

602

/* EOF */

603

if(bytes_read == 0){

604

break;

605

}

606

/* check bytes_read for failure */

607

if(bytes_read < 0){

608

perror_plus("read");

609

free(params.data);

610

params.data = NULL;

611

dhparamsfilename = NULL;

612

break;

613

}

614

params.size += (unsigned int)bytes_read;

615

}

616

ret = close(dhpfile);

617

if(ret == -1){

618

perror_plus("close");

619

}

620

if(params.data == NULL){

621

dhparamsfilename = NULL;

622

}

623

if(dhparamsfilename == NULL){

624

break;

625

}

626

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

627

GNUTLS_X509_FMT_PEM);

628

if(ret != GNUTLS_E_SUCCESS){

629

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

630

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

631

safer_gnutls_strerror(ret));

632

dhparamsfilename = NULL;

633

}

634

free(params.data);

635

} while(false);

636

}

637

if(dhparamsfilename == NULL){

638

if(mc->dh_bits == 0){

639

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

640

/* Try to read the private key file */

641

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

642

do {

643

int secfile = open(seckeyfilename, O_RDONLY);

644

if(secfile == -1){

645

perror_plus("open");

646

break;

647

}

648

size_t buffer_capacity = 0;

649

while(true){

650

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

651

(size_t)buffer.size,

652

(size_t)buffer_capacity);

653

if(buffer_capacity == 0){

654

perror_plus("incbuffer");

655

free(buffer.data);

656

buffer.data = NULL;

657

break;

658

}

659

ssize_t bytes_read = read(secfile,

660

buffer.data + buffer.size,

661

BUFFER_SIZE);

662

/* EOF */

663

if(bytes_read == 0){

664

break;

665

}

666

/* check bytes_read for failure */

667

if(bytes_read < 0){

668

perror_plus("read");

669

free(buffer.data);

670

buffer.data = NULL;

671

break;

672

}

673

buffer.size += (unsigned int)bytes_read;

674

}

675

close(secfile);

676

} while(false);

677

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

678

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

679

if(buffer.data != NULL){

680

{

681

gnutls_openpgp_privkey_t privkey = NULL;

682

ret = gnutls_openpgp_privkey_init(&privkey);

683

if(ret != GNUTLS_E_SUCCESS){

684

fprintf_plus(stderr, "Error initializing OpenPGP key"

685

" structure: %s",

686

safer_gnutls_strerror(ret));

687

free(buffer.data);

688

buffer.data = NULL;

689

} else {

690

ret = gnutls_openpgp_privkey_import

691

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

692

if(ret != GNUTLS_E_SUCCESS){

693

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

694

safer_gnutls_strerror(ret));

695

privkey = NULL;

696

}

697

free(buffer.data);

698

buffer.data = NULL;

699

if(privkey != NULL){

700

/* Use private key to suggest an appropriate

701

sec_param */

702

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

703

gnutls_openpgp_privkey_deinit(privkey);

704

if(debug){

705

fprintf_plus(stderr, "This OpenPGP key implies using"

706

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

707

safe_string(gnutls_sec_param_get_name

708

(sec_param)));

709

}

710

}

711

}

712

}

713

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

714

/* Err on the side of caution */

715

sec_param = GNUTLS_SEC_PARAM_ULTRA;

716

if(debug){

717

fprintf_plus(stderr, "Falling back to security parameter"

718

" \"%s\"\n",

719

safe_string(gnutls_sec_param_get_name

720

(sec_param)));

721

}

722

}

723

}

724

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

725

if(uret != 0){

726

mc->dh_bits = uret;

727

if(debug){

728

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

729

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

730

safe_string(gnutls_sec_param_get_name

731

(sec_param)),

732

mc->dh_bits);

733

}

734

} else {

735

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

736

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

737

safe_string(gnutls_sec_param_get_name

738

(sec_param)),

739

safer_gnutls_strerror(ret));

740

goto globalfail;

741

}

742

} else if(debug){

743

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

744

mc->dh_bits);

745

}

746

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

747

if(ret != GNUTLS_E_SUCCESS){

748

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

749

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

750

safer_gnutls_strerror(ret));

751

goto globalfail;

752

}

753

}

754

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

548

755

549

756

return 0;

550

757

551

758

globalfail:

552

759

553

gnutls_certificate_free_credentials(mc.cred);

554

gnutls_global_deinit();

555

gnutls_dh_params_deinit(mc.dh_params);

760

gnutls_certificate_free_credentials(mc->cred);

761

gnutls_dh_params_deinit(mc->dh_params);

556

762

return -1;

557

763

}

558

764

559

static int init_gnutls_session(gnutls_session_t *session){

765

__attribute__((nonnull, warn_unused_result))

766

static int init_gnutls_session(gnutls_session_t *session,

767

mandos_context *mc){

560

768

int ret;

561

769

/* GnuTLS session creation */

562

770

do {

574

782

{

575

783

const char *err;

576

784

do {

577

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

785

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

578

786

if(quit_now){

579

787

gnutls_deinit(*session);

580

788

return -1;

591

799

592

800

do {

593

801

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

594

mc.cred);

802

mc->cred);

595

803

if(quit_now){

596

804

gnutls_deinit(*session);

597

805

return -1;

607

815

/* ignore client certificate if any. */

608

816

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

609

817

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

611

612

818

return 0;

613

819

}

614

820

616

822

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

617

823

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

618

824

825

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

826

__attribute__((warn_unused_result))

827

int raise_privileges(void){

828

int old_errno = errno;

829

int ret = 0;

830

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

831

ret = errno;

832

}

833

errno = old_errno;

834

return ret;

835

}

836

837

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

838

__attribute__((warn_unused_result))

839

int raise_privileges_permanently(void){

840

int old_errno = errno;

841

int ret = raise_privileges();

842

if(ret != 0){

843

errno = old_errno;

844

return ret;

845

}

846

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

847

ret = errno;

848

}

849

errno = old_errno;

850

return ret;

851

}

852

853

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

854

__attribute__((warn_unused_result))

855

int lower_privileges(void){

856

int old_errno = errno;

857

int ret = 0;

858

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

859

ret = errno;

860

}

861

errno = old_errno;

862

return ret;

863

}

864

865

/* Lower privileges permanently */

866

__attribute__((warn_unused_result))

867

int lower_privileges_permanently(void){

868

int old_errno = errno;

869

int ret = 0;

870

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

871

ret = errno;

872

}

873

errno = old_errno;

874

return ret;

875

}

876

877

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

878

__attribute__((nonnull, warn_unused_result))

879

static bool add_delete_local_route(const bool add,

880

const char *address,

881

AvahiIfIndex if_index){

882

int ret;

883

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

884

char add_arg[] = "add";

885

char delete_arg[] = "delete";

886

char debug_flag[] = "--debug";

887

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

888

if(pluginhelperdir == NULL){

889

if(debug){

890

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

891

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

892

}

893

return false;

894

}

895

896

char interface[IF_NAMESIZE];

897

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

898

perror_plus("if_indextoname");

899

return false;

900

}

901

902

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

903

if(devnull == -1){

904

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

905

return false;

906

}

907

pid_t pid = fork();

908

if(pid == 0){

909

/* Child */

910

/* Raise privileges */

911

errno = raise_privileges_permanently();

912

if(errno != 0){

913

perror_plus("Failed to raise privileges");

914

/* _exit(EX_NOPERM); */

915

} else {

916

/* Set group */

917

errno = 0;

918

ret = setgid(0);

919

if(ret == -1){

920

perror_plus("setgid");

921

_exit(EX_NOPERM);

922

}

923

/* Reset supplementary groups */

924

errno = 0;

925

ret = setgroups(0, NULL);

926

if(ret == -1){

927

perror_plus("setgroups");

928

_exit(EX_NOPERM);

929

}

930

}

931

ret = dup2(devnull, STDIN_FILENO);

932

if(ret == -1){

933

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

934

_exit(EX_OSERR);

935

}

936

ret = close(devnull);

937

if(ret == -1){

938

perror_plus("close");

939

_exit(EX_OSERR);

940

}

941

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

942

if(ret == -1){

943

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

944

_exit(EX_OSERR);

945

}

946

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

947

O_RDONLY

948

| O_DIRECTORY

949

| O_PATH

950

| O_CLOEXEC));

951

if(helperdir_fd == -1){

952

perror_plus("open");

953

_exit(EX_UNAVAILABLE);

954

}

955

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

956

helper, O_RDONLY));

957

if(helper_fd == -1){

958

perror_plus("openat");

959

close(helperdir_fd);

960

_exit(EX_UNAVAILABLE);

961

}

962

close(helperdir_fd);

963

#ifdef __GNUC__

964

#pragma GCC diagnostic push

965

#pragma GCC diagnostic ignored "-Wcast-qual"

966

#endif

967

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

968

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

969

interface, debug ? debug_flag : NULL, NULL },

970

environ) == -1){

971

#ifdef __GNUC__

972

#pragma GCC diagnostic pop

973

#endif

974

perror_plus("fexecve");

975

_exit(EXIT_FAILURE);

976

}

977

}

978

if(pid == -1){

979

perror_plus("fork");

980

return false;

981

}

982

int status;

983

pid_t pret = -1;

984

errno = 0;

985

do {

986

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

987

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

988

int errno_raising = 0;

989

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

990

errno_raising = errno;

991

perror_plus("Failed to raise privileges in order to"

992

" kill helper program");

993

}

994

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

995

perror_plus("kill");

996

}

997

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

998

perror_plus("Failed to lower privileges after killing"

999

" helper program");

1000

}

1001

return false;

1002

}

1003

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

1004

if(pret == -1){

1005

perror_plus("waitpid");

1006

return false;

1007

}

1008

if(WIFEXITED(status)){

1009

if(WEXITSTATUS(status) != 0){

1010

fprintf_plus(stderr, "Error: iprouteadddel exited"

1011

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

1012

return false;

1013

}

1014

return true;

1015

}

1016

if(WIFSIGNALED(status)){

1017

fprintf_plus(stderr, "Error: iprouteadddel died by"

1018

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

1019

return false;

1020

}

1021

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

1022

return false;

1023

}

1024

1025

__attribute__((nonnull, warn_unused_result))

1026

static bool add_local_route(const char *address,

1027

AvahiIfIndex if_index){

1028

if(debug){

1029

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

1030

}

1031

return add_delete_local_route(true, address, if_index);

1032

}

1033

1034

__attribute__((nonnull, warn_unused_result))

1035

static bool delete_local_route(const char *address,

1036

AvahiIfIndex if_index){

1037

if(debug){

1038

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

1039

}

1040

return add_delete_local_route(false, address, if_index);

1041

}

1042

619

1043

/* Called when a Mandos server is found */

620

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

1044

__attribute__((nonnull, warn_unused_result))

1045

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

621

1046

AvahiIfIndex if_index,

622

int af){

1047

int af, mandos_context *mc){

623

1048

int ret, tcp_sd = -1;

624

1049

ssize_t sret;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

1050

struct sockaddr_storage to;

629

1051

char *buffer = NULL;

630

1052

char *decrypted_buffer = NULL;

631

1053

size_t buffer_length = 0;

634

1056

int retval = -1;

635

1057

gnutls_session_t session;

636

1058

int pf; /* Protocol family */

1059

bool route_added = false;

637

1060

638

1061

errno = 0;

639

1062

655

1078

return -1;

656

1079

}

657

1080

658

ret = init_gnutls_session(&session);

1081

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

1082

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

1083

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

1084

bool match = false;

1085

{

1086

char *interface = NULL;

1087

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

1088

mc->interfaces_size,

1089

interface))){

1090

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

1091

match = true;

1092

break;

1093

}

1094

}

1095

}

1096

if(not match){

1097

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

1098

connect to the server */

1099

if(debug){

1100

char interface[IF_NAMESIZE];

1101

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

1102

perror_plus("if_indextoname");

1103

} else {

1104

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

1105

" \"%s\"\n",

1106

if_indextoname((unsigned int)if_index,

1107

interface));

1108

}

1109

}

1110

return -1;

1111

}

1112

}

1113

1114

ret = init_gnutls_session(&session, mc);

659

1115

if(ret != 0){

660

1116

return -1;

661

1117

}

662

1118

663

1119

if(debug){

664

1120

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

665

PRIu16 "\n", ip, port);

1121

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

666

1122

}

667

1123

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1124

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

669

1125

if(tcp_sd < 0){

670

1126

int e = errno;

671

1127

perror_plus("socket");

678

1134

goto mandos_end;

679

1135

}

680

1136

681

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

682

1137

if(af == AF_INET6){

683

to.in6.sin6_family = (sa_family_t)af;

684

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

1138

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

1139

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

1140

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

685

1141

} else { /* IPv4 */

686

to.in.sin_family = (sa_family_t)af;

687

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

1142

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

1143

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

1144

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

688

1145

}

689

1146

if(ret < 0 ){

690

1147

int e = errno;

699

1156

goto mandos_end;

700

1157

}

701

1158

if(af == AF_INET6){

702

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

703

-Wconversion and

704

-Wunreachable-code */

705

706

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

707

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

708

-Wunreachable-code*/

1159

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

1160

if(IN6_IS_ADDR_LINKLOCAL

1161

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

709

1162

if(if_index == AVAHI_IF_UNSPEC){

710

1163

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

711

1164

" incomplete without a network interface\n");

713

1166

goto mandos_end;

714

1167

}

715

1168

/* Set the network interface number as scope */

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1169

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

717

1170

}

718

1171

} else {

719

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

720

-Wconversion and

721

-Wunreachable-code */

1172

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

722

1173

}

723

1174

724

1175

if(quit_now){

732

1183

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

733

1184

perror_plus("if_indextoname");

734

1185

} else {

735

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

736

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

1186

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

1187

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

737

1188

}

738

1189

} else {

739

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

740

ip, port);

1190

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

1191

ip, (uintmax_t)port);

741

1192

}

742

1193

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

743

1194

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

744

const char *pcret;

745

if(af == AF_INET6){

746

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

747

sizeof(addrstr));

748

} else {

749

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

750

sizeof(addrstr));

751

}

752

if(pcret == NULL){

753

perror_plus("inet_ntop");

754

} else {

755

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

756

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

757

}

758

}

759

}

760

761

if(quit_now){

762

errno = EINTR;

763

goto mandos_end;

764

}

765

766

if(af == AF_INET6){

767

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

768

} else {

769

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

770

}

771

if(ret < 0){

772

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

773

int e = errno;

774

perror_plus("connect");

775

errno = e;

776

}

777

goto mandos_end;

778

}

779

780

if(quit_now){

781

errno = EINTR;

782

goto mandos_end;

1195

if(af == AF_INET6){

1196

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

1197

sizeof(struct sockaddr_in6),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

} else {

1201

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

1202

sizeof(struct sockaddr_in),

1203

addrstr, sizeof(addrstr), NULL, 0,

1204

NI_NUMERICHOST);

1205

}

1206

if(ret == EAI_SYSTEM){

1207

perror_plus("getnameinfo");

1208

} else if(ret != 0) {

1209

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

1210

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

1211

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

1212

}

1213

}

1214

1215

if(quit_now){

1216

errno = EINTR;

1217

goto mandos_end;

1218

}

1219

1220

while(true){

1221

if(af == AF_INET6){

1222

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

1223

sizeof(struct sockaddr_in6));

1224

} else {

1225

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

1226

sizeof(struct sockaddr_in));

1227

}

1228

if(ret < 0){

1229

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

1230

and if_index != AVAHI_IF_UNSPEC

1231

and connect_to == NULL

1232

and not route_added and

1233

((af == AF_INET6 and not

1234

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1235

&to)->sin6_addr)))

1236

or (af == AF_INET and

1237

/* Not a a IPv4LL address */

1238

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

1239

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

1240

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

1241

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

1242

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

1243

connect to a Mandos server announced by Avahi on a server

1244

host with a global address. Work around this by retrying

1245

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

1246

1247

Avahi bug reference:

1248

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

1249

https://bugs.debian.org/587961

1250

*/

1251

if(debug){

1252

fprintf_plus(stderr, "Mandos server unreachable, trying"

1253

" direct route\n");

1254

}

1255

int e = errno;

1256

route_added = add_local_route(ip, if_index);

1257

if(route_added){

1258

continue;

1259

}

1260

errno = e;

1261

}

1262

if(errno != ECONNREFUSED or debug){

1263

int e = errno;

1264

perror_plus("connect");

1265

errno = e;

1266

}

1267

goto mandos_end;

1268

}

1269

1270

if(quit_now){

1271

errno = EINTR;

1272

goto mandos_end;

1273

}

1274

break;

783

1275

}

784

1276

785

1277

const char *out = mandos_protocol_version;

821

1313

goto mandos_end;

822

1314

}

823

1315

824

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

825

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1316

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

1317

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

1318

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

1319

gnutls_transport_set_ptr(session,

1320

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

826

1321

827

1322

if(quit_now){

828

1323

errno = EINTR;

933

1428

if(buffer_length > 0){

934

1429

ssize_t decrypted_buffer_size;

935

1430

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

936

&decrypted_buffer);

1431

&decrypted_buffer, mc);

937

1432

if(decrypted_buffer_size >= 0){

938

1433

1434

clearerr(stdout);

939

1435

written = 0;

940

1436

while(written < (size_t) decrypted_buffer_size){

941

1437

if(quit_now){

957

1453

}

958

1454

written += (size_t)ret;

959

1455

}

1456

ret = fflush(stdout);

1457

if(ret != 0){

1458

int e = errno;

1459

if(debug){

1460

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

1461

strerror(errno));

1462

}

1463

errno = e;

1464

goto mandos_end;

1465

}

960

1466

retval = 0;

961

1467

}

962

1468

}

965

1471

966

1472

mandos_end:

967

1473

{

1474

if(route_added){

1475

if(not delete_local_route(ip, if_index)){

1476

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

1477

" interface %d", ip, if_index);

1478

}

1479

}

968

1480

int e = errno;

969

1481

free(decrypted_buffer);

970

1482

free(buffer);

971

1483

if(tcp_sd >= 0){

972

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

1484

ret = close(tcp_sd);

973

1485

}

974

1486

if(ret == -1){

975

1487

if(e == 0){

1000

1512

AVAHI_GCC_UNUSED AvahiStringList *txt,

1001

1513

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1002

1514

flags,

1003

AVAHI_GCC_UNUSED void* userdata){

1004

assert(r);

1515

void *mc){

1516

if(r == NULL){

1517

return;

1518

}

1005

1519

1006

1520

/* Called whenever a service has been resolved successfully or

1007

1521

timed out */

1008

1522

1009

1523

if(quit_now){

1524

avahi_s_service_resolver_free(r);

1010

1525

return;

1011

1526

}

1012

1527

1016

1531

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

1017

1532

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

1018

1533

domain,

1019

avahi_strerror(avahi_server_errno(mc.server)));

1534

avahi_strerror(avahi_server_errno

1535

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

1020

1536

break;

1021

1537

1022

1538

case AVAHI_RESOLVER_FOUND:

1028

1544

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

1029

1545

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

1030

1546

}

1031

int ret = start_mandos_communication(ip, port, interface,

1032

avahi_proto_to_af(proto));

1547

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

1548

interface,

1549

avahi_proto_to_af(proto),

1550

mc);

1033

1551

if(ret == 0){

1034

avahi_simple_poll_quit(mc.simple_poll);

1552

avahi_simple_poll_quit(simple_poll);

1035

1553

} else {

1036

if(not add_server(ip, port, interface,

1037

avahi_proto_to_af(proto))){

1554

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

1555

avahi_proto_to_af(proto),

1556

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

1038

1557

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

1039

1558

" list\n", name);

1040

1559

}

1053

1572

const char *domain,

1054

1573

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1055

1574

flags,

1056

AVAHI_GCC_UNUSED void* userdata){

1057

assert(b);

1575

void *mc){

1576

if(b == NULL){

1577

return;

1578

}

1058

1579

1059

1580

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

1060

1581

is removed from the LAN */

1068

1589

case AVAHI_BROWSER_FAILURE:

1069

1590

1070

1591

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

1071

avahi_strerror(avahi_server_errno(mc.server)));

1072

avahi_simple_poll_quit(mc.simple_poll);

1592

avahi_strerror(avahi_server_errno

1593

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

1594

avahi_simple_poll_quit(simple_poll);

1073

1595

return;

1074

1596

1075

1597

case AVAHI_BROWSER_NEW:

1078

1600

the callback function is called the Avahi server will free the

1079

1601

resolver for us. */

1080

1602

1081

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

1082

name, type, domain, protocol, 0,

1083

resolve_callback, NULL) == NULL)

1603

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

1604

interface, protocol, name, type,

1605

domain, protocol, 0,

1606

resolve_callback, mc) == NULL)

1084

1607

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

1085

1608

" %s\n", name,

1086

avahi_strerror(avahi_server_errno(mc.server)));

1609

avahi_strerror(avahi_server_errno

1610

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

1087

1611

break;

1088

1612

1089

1613

case AVAHI_BROWSER_REMOVE:

1108

1632

signal_received = sig;

1109

1633

int old_errno = errno;

1110

1634

/* set main loop to exit */

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1635

if(simple_poll != NULL){

1636

avahi_simple_poll_quit(simple_poll);

1113

1637

}

1114

1638

errno = old_errno;

1115

1639

}

1116

1640

1641

__attribute__((nonnull, warn_unused_result))

1117

1642

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

1118

1643

int ret;

1644

int old_errno;

1119

1645

1120

1646

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

1121

1647

if(s < 0){

1648

old_errno = errno;

1122

1649

perror_plus("socket");

1650

errno = old_errno;

1123

1651

return false;

1124

1652

}

1125

strcpy(ifr->ifr_name, ifname);

1653

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

1654

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

1126

1655

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1127

1656

if(ret == -1){

1128

1657

if(debug){

1658

old_errno = errno;

1129

1659

perror_plus("ioctl SIOCGIFFLAGS");

1660

errno = old_errno;

1661

}

1662

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

1663

old_errno = errno;

1664

perror_plus("close");

1665

errno = old_errno;

1130

1666

}

1131

1667

return false;

1132

1668

}

1669

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

1670

old_errno = errno;

1671

perror_plus("close");

1672

errno = old_errno;

1673

}

1133

1674

return true;

1134

1675

}

1135

1676

1677

__attribute__((nonnull, warn_unused_result))

1136

1678

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

1137

1679

1138

1680

/* Reject the loopback device */

1180

1722

* corresponds to an acceptable network device.

1181

1723

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

1182

1724

*/

1725

__attribute__((nonnull, warn_unused_result))

1183

1726

int good_interface(const struct dirent *if_entry){

1184

1727

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

1185

1728

return 0;

1201

1744

}

1202

1745

1203

1746

/*

1204

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

1205

* corresponds to an acceptable network device which is up.

1206

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

1207

*/

1208

int up_interface(const struct dirent *if_entry){

1209

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

1210

return 0;

1211

}

1212

1213

struct ifreq ifr;

1214

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

1215

if(debug){

1216

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

1217

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

1218

}

1219

return 0;

1220

}

1221

1222

/* Reject down interfaces */

1223

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

1224

if(debug){

1225

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

1226

if_entry->d_name);

1227

}

1228

return 0;

1229

}

1230

1231

/* Reject non-running interfaces */

1232

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

1233

if(debug){

1234

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

1235

if_entry->d_name);

1236

}

1237

return 0;

1238

}

1239

1240

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

1241

return 0;

1242

}

1243

return 1;

1244

}

1245

1747

* This function determines if a network interface is up.

1748

*/

1749

__attribute__((nonnull, warn_unused_result))

1750

bool interface_is_up(const char *interface){

1751

struct ifreq ifr;

1752

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

1753

if(debug){

1754

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

1755

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

1756

}

1757

return false;

1758

}

1759

1760

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

1761

}

1762

1763

/*

1764

* This function determines if a network interface is running

1765

*/

1766

__attribute__((nonnull, warn_unused_result))

1767

bool interface_is_running(const char *interface){

1768

struct ifreq ifr;

1769

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

1770

if(debug){

1771

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

1772

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

1773

}

1774

return false;

1775

}

1776

1777

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

1778

}

1779

1780

__attribute__((nonnull, pure, warn_unused_result))

1246

1781

int notdotentries(const struct dirent *direntry){

1247

1782

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

1248

1783

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

1255

1790

}

1256

1791

1257

1792

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

1793

__attribute__((nonnull, warn_unused_result))

1258

1794

int runnable_hook(const struct dirent *direntry){

1259

1795

int ret;

1260

1796

size_t sret;

1268

1804

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

1269

1805

"abcdefghijklmnopqrstuvwxyz"

1270

1806

"0123456789"

1271

"_-");

1807

"_.-");

1272

1808

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

1273

1809

/* Contains non-allowed characters */

1274

1810

if(debug){

1278

1814

return 0;

1279

1815

}

1280

1816

1281

char *fullname = NULL;

1282

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

1283

if(ret < 0){

1284

perror_plus("asprintf");

1285

return 0;

1286

}

1287

1288

ret = stat(fullname, &st);

1817

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

1289

1818

if(ret == -1){

1290

1819

if(debug){

1291

1820

perror_plus("Could not stat hook");

1315

1844

return 1;

1316

1845

}

1317

1846

1318

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1847

__attribute__((nonnull, warn_unused_result))

1848

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1849

mandos_context *mc){

1319

1850

int ret;

1320

1851

struct timespec now;

1321

1852

struct timespec waited_time;

1322

1853

intmax_t block_time;

1323

1854

1324

1855

while(true){

1325

if(mc.current_server == NULL){

1326

if (debug){

1856

if(mc->current_server == NULL){

1857

if(debug){

1327

1858

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

1328

1859

" No timeout!\n");

1329

1860

}

1330

1861

ret = avahi_simple_poll_iterate(s, -1);

1331

1862

} else {

1332

if (debug){

1863

if(debug){

1333

1864

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

1334

1865

" it, or wait\n");

1335

1866

}

1342

1873

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

1343

1874

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

1344

1875

waited_time.tv_sec = (now.tv_sec

1345

- mc.current_server->last_seen.tv_sec);

1876

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

1346

1877

waited_time.tv_nsec = (now.tv_nsec

1347

- mc.current_server->last_seen.tv_nsec);

1878

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

1348

1879

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

1349

1880

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

1350

1881

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

1352

1883

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

1353

1884

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

1354

1885

1355

if (debug){

1886

if(debug){

1356

1887

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

1357

1888

block_time);

1358

1889

}

1359

1890

1360

1891

if(block_time <= 0){

1361

ret = start_mandos_communication(mc.current_server->ip,

1362

mc.current_server->port,

1363

mc.current_server->if_index,

1364

mc.current_server->af);

1892

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

1893

mc->current_server->port,

1894

mc->current_server->if_index,

1895

mc->current_server->af, mc);

1365

1896

if(ret == 0){

1366

avahi_simple_poll_quit(mc.simple_poll);

1897

avahi_simple_poll_quit(s);

1367

1898

return 0;

1368

1899

}

1369

1900

ret = clock_gettime(CLOCK_MONOTONIC,

1370

&mc.current_server->last_seen);

1901

&mc->current_server->last_seen);

1371

1902

if(ret == -1){

1372

1903

perror_plus("clock_gettime");

1373

1904

return -1;

1374

1905

}

1375

mc.current_server = mc.current_server->next;

1906

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

1376

1907

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

1377

1908

servers, but don't block */

1378

1909

}

1380

1911

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

1381

1912

}

1382

1913

if(ret != 0){

1383

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

1914

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

1384

1915

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

1385

1916

}

1386

1917

}

1387

1918

}

1388

1919

}

1389

1920

1390

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

1921

__attribute__((nonnull))

1922

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

1391

1923

const float delay){

1392

struct dirent **direntries;

1393

struct dirent *direntry;

1394

int ret;

1395

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

1396

alphasort);

1924

struct dirent **direntries = NULL;

1925

if(hookdir_fd == -1){

1926

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1927

| O_CLOEXEC);

1928

if(hookdir_fd == -1){

1929

if(errno == ENOENT){

1930

if(debug){

1931

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

1932

" found\n", hookdir);

1933

}

1934

} else {

1935

perror_plus("open");

1936

}

1937

return;

1938

}

1939

}

1940

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

1941

if(devnull == -1){

1942

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

1943

return;

1944

}

1945

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

1946

runnable_hook, alphasort);

1397

1947

if(numhooks == -1){

1398

1948

perror_plus("scandir");

1399

} else {

1400

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

1401

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

1402

direntry = direntries[i];

1403

char *fullname = NULL;

1404

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

1405

if(ret < 0){

1949

close(devnull);

1950

return;

1951

}

1952

struct dirent *direntry;

1953

int ret;

1954

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

1955

direntry = direntries[i];

1956

if(debug){

1957

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

1958

direntry->d_name);

1959

}

1960

pid_t hook_pid = fork();

1961

if(hook_pid == 0){

1962

/* Child */

1963

/* Raise privileges */

1964

errno = raise_privileges_permanently();

1965

if(errno != 0){

1966

perror_plus("Failed to raise privileges");

1967

_exit(EX_NOPERM);

1968

}

1969

/* Set group */

1970

errno = 0;

1971

ret = setgid(0);

1972

if(ret == -1){

1973

perror_plus("setgid");

1974

_exit(EX_NOPERM);

1975

}

1976

/* Reset supplementary groups */

1977

errno = 0;

1978

ret = setgroups(0, NULL);

1979

if(ret == -1){

1980

perror_plus("setgroups");

1981

_exit(EX_NOPERM);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

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

1989

if(ret == -1){

1990

perror_plus("setenv");

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

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

1999

if(ret == -1){

2000

perror_plus("setenv");

2001

_exit(EX_OSERR);

2002

}

2003

char *delaystring;

2004

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

2005

if(ret == -1){

1406

2006

perror_plus("asprintf");

1407

continue;

1408

}

1409

if(debug){

1410

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

1411

direntry->d_name);

1412

}

1413

pid_t hook_pid = fork();

1414

if(hook_pid == 0){

1415

/* Child */

1416

/* Raise privileges */

1417

errno = 0;

1418

ret = seteuid(0);

1419

if(ret == -1){

1420

perror_plus("seteuid");

1421

}

1422

/* Raise privileges even more */

1423

errno = 0;

1424

ret = setuid(0);

1425

if(ret == -1){

1426

perror_plus("setuid");

1427

}

1428

/* Set group */

1429

errno = 0;

1430

ret = setgid(0);

1431

if(ret == -1){

1432

perror_plus("setgid");

1433

}

1434

/* Reset supplementary groups */

1435

errno = 0;

1436

ret = setgroups(0, NULL);

1437

if(ret == -1){

1438

perror_plus("setgroups");

1439

}

1440

dup2(devnull, STDIN_FILENO);

1441

close(devnull);

1442

dup2(STDERR_FILENO, STDOUT_FILENO);

1443

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

1444

if(ret == -1){

1445

perror_plus("setenv");

1446

_exit(EX_OSERR);

1447

}

1448

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

1449

if(ret == -1){

1450

perror_plus("setenv");

1451

_exit(EX_OSERR);

1452

}

1453

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

1454

if(ret == -1){

1455

perror_plus("setenv");

1456

_exit(EX_OSERR);

1457

}

1458

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

1459

if(ret == -1){

1460

perror_plus("setenv");

1461

_exit(EX_OSERR);

1462

}

1463

char *delaystring;

1464

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

1465

if(ret == -1){

1466

perror_plus("asprintf");

1467

_exit(EX_OSERR);

1468

}

1469

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

1470

if(ret == -1){

1471

free(delaystring);

1472

perror_plus("setenv");

1473

_exit(EX_OSERR);

1474

}

2007

_exit(EX_OSERR);

2008

}

2009

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

2010

if(ret == -1){

1475

2011

free(delaystring);

1476

if(connect_to != NULL){

1477

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

1478

if(ret == -1){

1479

perror_plus("setenv");

1480

_exit(EX_OSERR);

1481

}

1482

}

1483

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

1484

perror_plus("execl");

1485

_exit(EXIT_FAILURE);

1486

}

1487

} else {

1488

int status;

1489

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

1490

perror_plus("waitpid");

1491

free(fullname);

1492

continue;

1493

}

1494

if(WIFEXITED(status)){

1495

if(WEXITSTATUS(status) != 0){

1496

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

1497

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

1498

WEXITSTATUS(status));

1499

free(fullname);

1500

continue;

1501

}

1502

} else if(WIFSIGNALED(status)){

1503

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

1504

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

1505

WTERMSIG(status));

1506

free(fullname);

1507

continue;

1508

} else {

1509

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

1510

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

1511

free(fullname);

1512

continue;

1513

}

1514

}

1515

free(fullname);

1516

if(debug){

1517

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

1518

direntry->d_name);

1519

}

1520

}

1521

close(devnull);

1522

}

1523

return true;

2012

perror_plus("setenv");

2013

_exit(EX_OSERR);

2014

}

2015

free(delaystring);

2016

if(connect_to != NULL){

2017

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

2018

if(ret == -1){

2019

perror_plus("setenv");

2020

_exit(EX_OSERR);

2021

}

2022

}

2023

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

2024

direntry->d_name,

2025

O_RDONLY));

2026

if(hook_fd == -1){

2027

perror_plus("openat");

2028

_exit(EXIT_FAILURE);

2029

}

2030

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

2031

perror_plus("close");

2032

_exit(EXIT_FAILURE);

2033

}

2034

ret = dup2(devnull, STDIN_FILENO);

2035

if(ret == -1){

2036

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

2037

_exit(EX_OSERR);

2038

}

2039

ret = close(devnull);

2040

if(ret == -1){

2041

perror_plus("close");

2042

_exit(EX_OSERR);

2043

}

2044

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2045

if(ret == -1){

2046

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

2047

_exit(EX_OSERR);

2048

}

2049

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

2050

environ) == -1){

2051

perror_plus("fexecve");

2052

_exit(EXIT_FAILURE);

2053

}

2054

} else {

2055

if(hook_pid == -1){

2056

perror_plus("fork");

2057

free(direntry);

2058

continue;

2059

}

2060

int status;

2061

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

2062

perror_plus("waitpid");

2063

free(direntry);

2064

continue;

2065

}

2066

if(WIFEXITED(status)){

2067

if(WEXITSTATUS(status) != 0){

2068

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

2069

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

2070

WEXITSTATUS(status));

2071

free(direntry);

2072

continue;

2073

}

2074

} else if(WIFSIGNALED(status)){

2075

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

2076

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

2077

WTERMSIG(status));

2078

free(direntry);

2079

continue;

2080

} else {

2081

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

2082

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

2083

free(direntry);

2084

continue;

2085

}

2086

}

2087

if(debug){

2088

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

2089

direntry->d_name);

2090

}

2091

free(direntry);

2092

}

2093

free(direntries);

2094

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

2095

perror_plus("close");

2096

} else {

2097

hookdir_fd = -1;

2098

}

2099

close(devnull);

2100

}

2101

2102

__attribute__((nonnull, warn_unused_result))

2103

int bring_up_interface(const char *const interface,

2104

const float delay){

2105

int old_errno = errno;

2106

int ret;

2107

struct ifreq network;

2108

unsigned int if_index = if_nametoindex(interface);

2109

if(if_index == 0){

2110

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

2111

errno = old_errno;

2112

return ENXIO;

2113

}

2114

2115

if(quit_now){

2116

errno = old_errno;

2117

return EINTR;

2118

}

2119

2120

if(not interface_is_up(interface)){

2121

int ret_errno = 0;

2122

int ioctl_errno = 0;

2123

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

2124

ret_errno = errno;

2125

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

2126

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

2127

errno = old_errno;

2128

return ret_errno;

2129

}

2130

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

2131

2132

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

2133

if(sd == -1){

2134

ret_errno = errno;

2135

perror_plus("socket");

2136

errno = old_errno;

2137

return ret_errno;

2138

}

2139

2140

if(quit_now){

2141

ret = close(sd);

2142

if(ret == -1){

2143

perror_plus("close");

2144

}

2145

errno = old_errno;

2146

return EINTR;

2147

}

2148

2149

if(debug){

2150

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

2151

interface);

2152

}

2153

2154

/* Raise privileges */

2155

ret_errno = raise_privileges();

2156

if(ret_errno != 0){

2157

errno = ret_errno;

2158

perror_plus("Failed to raise privileges");

2159

}

2160

2161

#ifdef __linux__

2162

int ret_linux;

2163

bool restore_loglevel = false;

2164

if(ret_errno == 0){

2165

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2166

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

2167

ret_linux = klogctl(8, NULL, 5);

2168

if(ret_linux == -1){

2169

perror_plus("klogctl");

2170

} else {

2171

restore_loglevel = true;

2172

}

2173

}

2174

#endif /* __linux__ */

2175

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

2176

ioctl_errno = errno;

2177

#ifdef __linux__

2178

if(restore_loglevel){

2179

ret_linux = klogctl(7, NULL, 0);

2180

if(ret_linux == -1){

2181

perror_plus("klogctl");

2182

}

2183

}

2184

#endif /* __linux__ */

2185

2186

/* If raise_privileges() succeeded above */

2187

if(ret_errno == 0){

2188

/* Lower privileges */

2189

ret_errno = lower_privileges();

2190

if(ret_errno != 0){

2191

errno = ret_errno;

2192

perror_plus("Failed to lower privileges");

2193

}

2194

}

2195

2196

/* Close the socket */

2197

ret = close(sd);

2198

if(ret == -1){

2199

perror_plus("close");

2200

}

2201

2202

if(ret_setflags == -1){

2203

errno = ioctl_errno;

2204

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2205

errno = old_errno;

2206

return ioctl_errno;

2207

}

2208

} else if(debug){

2209

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

2210

interface);

2211

}

2212

2213

/* Sleep checking until interface is running.

2214

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

2215

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

2216

if(interface_is_running(interface)){

2217

break;

2218

}

2219

struct timespec sleeptime = { .tv_nsec = 250000000 };

2220

ret = nanosleep(&sleeptime, NULL);

2221

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

2222

perror_plus("nanosleep");

2223

}

2224

}

2225

2226

errno = old_errno;

2227

return 0;

2228

}

2229

2230

__attribute__((nonnull, warn_unused_result))

2231

int take_down_interface(const char *const interface){

2232

int old_errno = errno;

2233

struct ifreq network;

2234

unsigned int if_index = if_nametoindex(interface);

2235

if(if_index == 0){

2236

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

2237

errno = old_errno;

2238

return ENXIO;

2239

}

2240

if(interface_is_up(interface)){

2241

int ret_errno = 0;

2242

int ioctl_errno = 0;

2243

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

2244

ret_errno = errno;

2245

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

2246

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

2247

errno = old_errno;

2248

return ret_errno;

2249

}

2250

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

2251

2252

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

2253

if(sd == -1){

2254

ret_errno = errno;

2255

perror_plus("socket");

2256

errno = old_errno;

2257

return ret_errno;

2258

}

2259

2260

if(debug){

2261

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

2262

interface);

2263

}

2264

2265

/* Raise privileges */

2266

ret_errno = raise_privileges();

2267

if(ret_errno != 0){

2268

errno = ret_errno;

2269

perror_plus("Failed to raise privileges");

2270

}

2271

2272

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

2273

ioctl_errno = errno;

2274

2275

/* If raise_privileges() succeeded above */

2276

if(ret_errno == 0){

2277

/* Lower privileges */

2278

ret_errno = lower_privileges();

2279

if(ret_errno != 0){

2280

errno = ret_errno;

2281

perror_plus("Failed to lower privileges");

2282

}

2283

}

2284

2285

/* Close the socket */

2286

int ret = close(sd);

2287

if(ret == -1){

2288

perror_plus("close");

2289

}

2290

2291

if(ret_setflags == -1){

2292

errno = ioctl_errno;

2293

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2294

errno = old_errno;

2295

return ioctl_errno;

2296

}

2297

} else if(debug){

2298

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

2299

interface);

2300

}

2301

2302

errno = old_errno;

2303

return 0;

1524

2304

}

1525

2305

1526

2306

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

2307

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

2308

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

2309

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

2310

.current_server = NULL, .interfaces = NULL,

2311

.interfaces_size = 0 };

1527

2312

AvahiSServiceBrowser *sb = NULL;

1528

int error;

2313

error_t ret_errno;

1529

2314

int ret;

1530

2315

intmax_t tmpmax;

1531

2316

char *tmp;

1532

2317

int exitcode = EXIT_SUCCESS;

1533

const char *interface = "";

1534

struct ifreq network;

1535

int sd = -1;

1536

bool take_down_interface = false;

1537

uid_t uid;

1538

gid_t gid;

1539

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

1540

bool tempdir_created = false;

2318

char *interfaces_to_take_down = NULL;

2319

size_t interfaces_to_take_down_size = 0;

2320

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

2321

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

2322

char *tempdir = NULL;

1541

2323

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1542

2324

const char *seckey = PATHDIR "/" SECKEY;

1543

2325

const char *pubkey = PATHDIR "/" PUBKEY;

2326

const char *dh_params_file = NULL;

2327

char *interfaces_hooks = NULL;

1544

2328

1545

2329

bool gnutls_initialized = false;

1546

2330

bool gpgme_initialized = false;

1598

2382

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

1599

2383

" Diffie-Hellman key exchange",

1600

2384

.group = 2 },

2385

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

2386

.arg = "FILE",

2387

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

2388

" for the Diffie-Hellman key exchange",

2389

.group = 2 },

1601

2390

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

1602

2391

.arg = "STRING",

1603

2392

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

1637

2426

connect_to = arg;

1638

2427

break;

1639

2428

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

1640

interface = arg;

2429

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

2430

arg, (int)',');

2431

if(ret_errno != 0){

2432

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

2433

}

1641

2434

break;

1642

2435

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

1643

2436

seckey = arg;

1654

2447

}

1655

2448

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

1656

2449

break;

2450

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

2451

dh_params_file = arg;

2452

break;

1657

2453

case 130: /* --priority */

1658

2454

mc.priority = arg;

1659

2455

break;

1699

2495

.args_doc = "",

1700

2496

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

1701

2497

" passwords from a Mandos server" };

1702

ret = argp_parse(&argp, argc, argv,

1703

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1704

switch(ret){

2498

ret_errno = argp_parse(&argp, argc, argv,

2499

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2500

switch(ret_errno){

1705

2501

case 0:

1706

2502

break;

1707

2503

case ENOMEM:

1708

2504

default:

1709

errno = ret;

2505

errno = ret_errno;

1710

2506

perror_plus("argp_parse");

1711

2507

exitcode = EX_OSERR;

1712

2508

goto end;

1715

2511

goto end;

1716

2512

}

1717

2513

}

1718

2514

1719

2515

{

1720

2516

/* Work around Debian bug #633582:

1721

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

2517

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

1722

2518

1723

/* Re-raise priviliges */

1724

errno = 0;

1725

ret = seteuid(0);

1726

if(ret == -1){

1727

perror_plus("seteuid");

2519

/* Re-raise privileges */

2520

ret = raise_privileges();

2521

if(ret != 0){

2522

errno = ret;

2523

perror_plus("Failed to raise privileges");

1728

2524

} else {

1729

2525

struct stat st;

1730

2526

1745

2541

}

1746

2542

}

1747

2543

}

1748

TEMP_FAILURE_RETRY(close(seckey_fd));

2544

close(seckey_fd);

1749

2545

}

1750

2546

}

1751

2547

1752

2548

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

1753

2549

int pubkey_fd = open(pubkey, O_RDONLY);

1754

2550

if(pubkey_fd == -1){

1766

2562

}

1767

2563

}

1768

2564

}

1769

TEMP_FAILURE_RETRY(close(pubkey_fd));

1770

}

1771

}

1772

2565

close(pubkey_fd);

2566

}

2567

}

2568

2569

if(dh_params_file != NULL

2570

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

2571

int dhparams_fd = open(dh_params_file, O_RDONLY);

2572

if(dhparams_fd == -1){

2573

perror_plus("open");

2574

} else {

2575

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

2576

if(ret == -1){

2577

perror_plus("fstat");

2578

} else {

2579

if(S_ISREG(st.st_mode)

2580

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

2581

ret = fchown(dhparams_fd, uid, gid);

2582

if(ret == -1){

2583

perror_plus("fchown");

2584

}

2585

}

2586

}

2587

close(dhparams_fd);

2588

}

2589

}

2590

1773

2591

/* Lower privileges */

1774

errno = 0;

1775

ret = seteuid(uid);

1776

if(ret == -1){

1777

perror_plus("seteuid");

2592

ret = lower_privileges();

2593

if(ret != 0){

2594

errno = ret;

2595

perror_plus("Failed to lower privileges");

2596

}

2597

}

2598

}

2599

2600

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

2601

{

2602

char *interface = NULL;

2603

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

2604

interface))){

2605

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

2606

and if_nametoindex(interface) == 0){

2607

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

2608

fprintf_plus(stderr, "Not using nonexisting interface"

2609

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

2610

}

2611

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

2612

interface = NULL;

1778

2613

}

1779

2614

}

1780

2615

}

1781

2616

1782

2617

/* Run network hooks */

1783

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

1784

goto end;

2618

{

2619

if(mc.interfaces != NULL){

2620

interfaces_hooks = malloc(mc.interfaces_size);

2621

if(interfaces_hooks == NULL){

2622

perror_plus("malloc");

2623

goto end;

2624

}

2625

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

2626

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

2627

}

2628

run_network_hooks("start", interfaces_hooks != NULL ?

2629

interfaces_hooks : "", delay);

1785

2630

}

1786

2631

1787

2632

if(not debug){

1788

2633

avahi_set_log_function(empty_log);

1789

2634

}

1790

2635

1791

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

1792

struct dirent **direntries;

1793

/* First look for interfaces that are up */

1794

ret = scandir(sys_class_net, &direntries, up_interface,

1795

alphasort);

1796

if(ret == 0){

1797

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

1798

free(direntries);

1799

ret = scandir(sys_class_net, &direntries, good_interface,

1800

alphasort);

1801

}

1802

if(ret >= 1){

1803

/* Pick the first interface returned */

1804

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

1805

if(debug){

1806

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

1807

}

1808

if(interface == NULL){

1809

perror_plus("malloc");

1810

free(direntries);

1811

exitcode = EXIT_FAILURE;

1812

goto end;

1813

}

1814

free(direntries);

1815

} else {

1816

free(direntries);

1817

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

1818

exitcode = EXIT_FAILURE;

1819

goto end;

1820

}

1821

}

1822

1823

2636

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

1824

2637

from the signal handler */

1825

2638

/* Initialize the pseudo-RNG for Avahi */

1826

2639

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

1827

mc.simple_poll = avahi_simple_poll_new();

1828

if(mc.simple_poll == NULL){

2640

simple_poll = avahi_simple_poll_new();

2641

if(simple_poll == NULL){

1829

2642

fprintf_plus(stderr,

1830

2643

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

1831

2644

exitcode = EX_UNAVAILABLE;

1895

2708

}

1896

2709

}

1897

2710

1898

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

1899

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

1900

if_index = (AvahiIfIndex) if_nametoindex(interface);

1901

if(if_index == 0){

1902

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

1903

exitcode = EX_UNAVAILABLE;

1904

goto end;

1905

}

1906

1907

if(quit_now){

1908

goto end;

1909

}

1910

1911

/* Re-raise priviliges */

1912

errno = 0;

1913

ret = seteuid(0);

1914

if(ret == -1){

1915

perror_plus("seteuid");

1916

}

1917

1918

#ifdef __linux__

1919

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1920

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

1921

ret = klogctl(8, NULL, 5);

1922

bool restore_loglevel = true;

1923

if(ret == -1){

1924

restore_loglevel = false;

1925

perror_plus("klogctl");

1926

}

1927

#endif /* __linux__ */

1928

1929

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1930

if(sd < 0){

1931

perror_plus("socket");

1932

exitcode = EX_OSERR;

1933

#ifdef __linux__

1934

if(restore_loglevel){

1935

ret = klogctl(7, NULL, 0);

1936

if(ret == -1){

1937

perror_plus("klogctl");

1938

}

1939

}

1940

#endif /* __linux__ */

1941

/* Lower privileges */

1942

errno = 0;

1943

ret = seteuid(uid);

1944

if(ret == -1){

1945

perror_plus("seteuid");

1946

}

1947

goto end;

1948

}

1949

strcpy(network.ifr_name, interface);

1950

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

1951

if(ret == -1){

1952

perror_plus("ioctl SIOCGIFFLAGS");

1953

#ifdef __linux__

1954

if(restore_loglevel){

1955

ret = klogctl(7, NULL, 0);

1956

if(ret == -1){

1957

perror_plus("klogctl");

1958

}

1959

}

1960

#endif /* __linux__ */

1961

exitcode = EX_OSERR;

1962

/* Lower privileges */

1963

errno = 0;

1964

ret = seteuid(uid);

1965

if(ret == -1){

1966

perror_plus("seteuid");

1967

}

1968

goto end;

1969

}

1970

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

1971

network.ifr_flags |= IFF_UP;

1972

take_down_interface = true;

1973

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

1974

if(ret == -1){

1975

take_down_interface = false;

1976

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1977

exitcode = EX_OSERR;

1978

#ifdef __linux__

1979

if(restore_loglevel){

1980

ret = klogctl(7, NULL, 0);

1981

if(ret == -1){

1982

perror_plus("klogctl");

2711

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

2712

if(mc.interfaces == NULL){

2713

struct dirent **direntries = NULL;

2714

/* Look for any good interfaces */

2715

ret = scandir(sys_class_net, &direntries, good_interface,

2716

alphasort);

2717

if(ret >= 1){

2718

/* Add all found interfaces to interfaces list */

2719

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

2720

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

2721

direntries[i]->d_name);

2722

if(ret_errno != 0){

2723

errno = ret_errno;

2724

perror_plus("argz_add");

2725

free(direntries[i]);

2726

continue;

2727

}

2728

if(debug){

2729

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

2730

direntries[i]->d_name);

2731

}

2732

free(direntries[i]);

2733

}

2734

free(direntries);

2735

} else {

2736

if(ret == 0){

2737

free(direntries);

2738

}

2739

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

2740

exitcode = EXIT_FAILURE;

2741

goto end;

2742

}

2743

}

2744

2745

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

2746

{

2747

char *interface = NULL;

2748

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

2749

interface))){

2750

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

2751

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

2752

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

2753

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

2754

interface);

2755

interface = NULL;

2756

while((interface = argz_next(mc.interfaces,

2757

mc.interfaces_size, interface))){

2758

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

2759

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

2760

interface);

2761

interface = NULL;

1983

2762

}

1984

2763

}

1985

#endif /* __linux__ */

1986

/* Lower privileges */

1987

errno = 0;

1988

ret = seteuid(uid);

1989

if(ret == -1){

1990

perror_plus("seteuid");

1991

}

1992

goto end;

1993

}

1994

}

1995

/* Sleep checking until interface is running.

1996

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

1997

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

1998

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

1999

if(ret == -1){

2000

perror_plus("ioctl SIOCGIFFLAGS");

2001

} else if(network.ifr_flags & IFF_RUNNING){

2002

2764

break;

2003

2765

}

2004

struct timespec sleeptime = { .tv_nsec = 250000000 };

2005

ret = nanosleep(&sleeptime, NULL);

2006

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

2007

perror_plus("nanosleep");

2008

}

2009

}

2010

if(not take_down_interface){

2011

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

2012

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

2013

if(ret == -1){

2014

perror_plus("close");

2015

}

2016

}

2017

#ifdef __linux__

2018

if(restore_loglevel){

2019

/* Restores kernel loglevel to default */

2020

ret = klogctl(7, NULL, 0);

2021

if(ret == -1){

2022

perror_plus("klogctl");

2023

}

2024

}

2025

#endif /* __linux__ */

2026

/* Lower privileges */

2027

errno = 0;

2028

/* Lower privileges */

2029

ret = seteuid(uid);

2030

if(ret == -1){

2031

perror_plus("seteuid");

2032

}

2766

bool interface_was_up = interface_is_up(interface);

2767

errno = bring_up_interface(interface, delay);

2768

if(not interface_was_up){

2769

if(errno != 0){

2770

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

2771

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

2772

} else {

2773

errno = argz_add(&interfaces_to_take_down,

2774

&interfaces_to_take_down_size,

2775

interface);

2776

if(errno != 0){

2777

perror_plus("argz_add");

2778

}

2779

}

2780

}

2781

}

2782

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

2783

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

2784

}

2785

}

2786

2787

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

2788

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

2789

if(debug){

2790

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

2791

mc.interfaces);

2792

}

2793

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

2033

2794

}

2034

2795

2035

2796

if(quit_now){

2036

2797

goto end;

2037

2798

}

2038

2799

2039

ret = init_gnutls_global(pubkey, seckey);

2800

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

2040

2801

if(ret == -1){

2041

2802

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

2042

2803

exitcode = EX_UNAVAILABLE;

2049

2810

goto end;

2050

2811

}

2051

2812

2052

if(mkdtemp(tempdir) == NULL){

2813

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

2814

tempdir = mkdtemp(run_tempdir);

2815

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

2816

if(debug){

2817

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

2818

run_tempdir, old_tempdir);

2819

}

2820

tempdir = mkdtemp(old_tempdir);

2821

}

2822

if(tempdir == NULL){

2053

2823

perror_plus("mkdtemp");

2054

2824

goto end;

2055

2825

}

2056

tempdir_created = true;

2057

2826

2058

2827

if(quit_now){

2059

2828

goto end;

2060

2829

}

2061

2830

2062

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

2831

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

2063

2832

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

2064

2833

exitcode = EX_UNAVAILABLE;

2065

2834

goto end;

2075

2844

/* Connect directly, do not use Zeroconf */

2076

2845

/* (Mainly meant for debugging) */

2077

2846

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

2847

2078

2848

if(address == NULL){

2079

2849

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

2080

2850

exitcode = EX_USAGE;

2085

2855

goto end;

2086

2856

}

2087

2857

2088

uint16_t port;

2858

in_port_t port;

2089

2859

errno = 0;

2090

2860

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

2091

2861

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

2092

or tmpmax != (uint16_t)tmpmax){

2862

or tmpmax != (in_port_t)tmpmax){

2093

2863

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

2094

2864

exitcode = EX_USAGE;

2095

2865

goto end;

2096

2866

}

2097

2867

2098

2868

if(quit_now){

2099

2869

goto end;

2100

2870

}

2101

2871

2102

port = (uint16_t)tmpmax;

2872

port = (in_port_t)tmpmax;

2103

2873

*address = '\0';

2104

2874

/* Colon in address indicates IPv6 */

2105

2875

int af;

2121

2891

}

2122

2892

2123

2893

while(not quit_now){

2124

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

2894

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

2895

&mc);

2125

2896

if(quit_now or ret == 0){

2126

2897

break;

2127

2898

}

2129

2900

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

2130

2901

(int)retry_interval);

2131

2902

}

2132

sleep((int)retry_interval);

2903

sleep((unsigned int)retry_interval);

2133

2904

}

2134

2905

2135

if (not quit_now){

2906

if(not quit_now){

2136

2907

exitcode = EXIT_SUCCESS;

2137

2908

}

2138

2909

2153

2924

config.publish_domain = 0;

2154

2925

2155

2926

/* Allocate a new server */

2156

mc.server = avahi_server_new(avahi_simple_poll_get

2157

(mc.simple_poll), &config, NULL,

2158

NULL, &error);

2927

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2928

&config, NULL, NULL, &ret);

2159

2929

2160

2930

/* Free the Avahi configuration data */

2161

2931

avahi_server_config_free(&config);

2164

2934

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

2165

2935

if(mc.server == NULL){

2166

2936

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

2167

avahi_strerror(error));

2937

avahi_strerror(ret));

2168

2938

exitcode = EX_UNAVAILABLE;

2169

2939

goto end;

2170

2940

}

2176

2946

/* Create the Avahi service browser */

2177

2947

sb = avahi_s_service_browser_new(mc.server, if_index,

2178

2948

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2179

NULL, 0, browse_callback, NULL);

2949

NULL, 0, browse_callback,

2950

(void *)&mc);

2180

2951

if(sb == NULL){

2181

2952

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

2182

2953

avahi_strerror(avahi_server_errno(mc.server)));

2193

2964

if(debug){

2194

2965

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

2195

2966

}

2196

2197

ret = avahi_loop_with_timeout(mc.simple_poll,

2198

(int)(retry_interval * 1000));

2967

2968

ret = avahi_loop_with_timeout(simple_poll,

2969

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

2199

2970

if(debug){

2200

2971

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

2201

2972

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

2204

2975

end:

2205

2976

2206

2977

if(debug){

2207

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

2978

if(signal_received){

2979

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

2980

argv[0], signal_received,

2981

strsignal(signal_received));

2982

} else {

2983

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

2984

}

2208

2985

}

2209

2986

2210

2987

/* Cleanup things */

2988

free(mc.interfaces);

2989

2211

2990

if(sb != NULL)

2212

2991

avahi_s_service_browser_free(sb);

2213

2992

2214

2993

if(mc.server != NULL)

2215

2994

avahi_server_free(mc.server);

2216

2995

2217

if(mc.simple_poll != NULL)

2218

avahi_simple_poll_free(mc.simple_poll);

2996

if(simple_poll != NULL)

2997

avahi_simple_poll_free(simple_poll);

2219

2998

2220

2999

if(gnutls_initialized){

2221

3000

gnutls_certificate_free_credentials(mc.cred);

2222

gnutls_global_deinit();

2223

3001

gnutls_dh_params_deinit(mc.dh_params);

2224

3002

}

2225

3003

2233

3011

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

2234

3012

while(mc.current_server != NULL){

2235

3013

server *next = mc.current_server->next;

3014

#ifdef __GNUC__

3015

#pragma GCC diagnostic push

3016

#pragma GCC diagnostic ignored "-Wcast-qual"

3017

#endif

3018

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

3019

#ifdef __GNUC__

3020

#pragma GCC diagnostic pop

3021

#endif

2236

3022

free(mc.current_server);

2237

3023

mc.current_server = next;

2238

3024

}

2239

3025

}

2240

3026

2241

/* Run network hooks */

2242

run_network_hooks("stop", interface, delay);

2243

2244

/* Re-raise priviliges */

3027

/* Re-raise privileges */

2245

3028

{

2246

errno = 0;

2247

ret = seteuid(0);

2248

if(ret == -1){

2249

perror_plus("seteuid");

3029

ret = raise_privileges();

3030

if(ret != 0){

3031

errno = ret;

3032

perror_plus("Failed to raise privileges");

3033

} else {

3034

3035

/* Run network hooks */

3036

run_network_hooks("stop", interfaces_hooks != NULL ?

3037

interfaces_hooks : "", delay);

3038

3039

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

3040

{

3041

char *interface = NULL;

3042

while((interface = argz_next(interfaces_to_take_down,

3043

interfaces_to_take_down_size,

3044

interface))){

3045

ret = take_down_interface(interface);

3046

if(ret != 0){

3047

errno = ret;

3048

perror_plus("Failed to take down interface");

3049

}

3050

}

3051

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

3052

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

3053

" down\n");

3054

}

3055

}

2250

3056

}

2251

3057

2252

/* Take down the network interface */

2253

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

2254

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

2255

if(ret == -1){

2256

perror_plus("ioctl SIOCGIFFLAGS");

2257

} else if(network.ifr_flags & IFF_UP){

2258

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

2259

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

2260

if(ret == -1){

2261

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2262

}

2263

}

2264

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

2265

if(ret == -1){

2266

perror_plus("close");

2267

}

3058

ret = lower_privileges_permanently();

3059

if(ret != 0){

3060

errno = ret;

3061

perror_plus("Failed to lower privileges permanently");

2268

3062

}

2269

3063

}

2270

/* Lower privileges permanently */

2271

errno = 0;

2272

ret = setuid(uid);

2273

if(ret == -1){

2274

perror_plus("setuid");

3064

3065

free(interfaces_to_take_down);

3066

free(interfaces_hooks);

3067

3068

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

3069

uintmax_t level){

3070

struct dirent **direntries = NULL;

3071

int dret;

3072

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

3073

O_RDONLY

3074

| O_NOFOLLOW

3075

| O_DIRECTORY

3076

| O_PATH));

3077

if(dir_fd == -1){

3078

perror_plus("open");

3079

return;

3080

}

3081

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

3082

notdotentries, alphasort);

3083

if(numentries >= 0){

3084

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

3085

if(debug){

3086

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

3087

dirname, direntries[i]->d_name);

3088

}

3089

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

3090

if(dret == -1){

3091

if(errno == EISDIR){

3092

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

3093

AT_REMOVEDIR);

3094

}

3095

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

3096

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

3097

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

3098

/* Recurse only in this special case */

3099

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

3100

dret = 0;

3101

}

3102

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

3103

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

3104

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

3105

}

3106

}

3107

free(direntries[i]);

3108

}

3109

3110

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

3111

free(direntries);

3112

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3113

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

3114

perror_plus("rmdir");

3115

}

3116

} else {

3117

perror_plus("scandirat");

3118

}

3119

close(dir_fd);

2275

3120

}

2276

3121

2277

3122

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

2278

if(tempdir_created){

2279

struct dirent **direntries = NULL;

2280

struct dirent *direntry = NULL;

2281

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

2282

alphasort);

2283

if (numentries > 0){

2284

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

2285

direntry = direntries[i];

2286

char *fullname = NULL;

2287

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

2288

direntry->d_name);

2289

if(ret < 0){

2290

perror_plus("asprintf");

2291

continue;

2292

}

2293

ret = remove(fullname);

2294

if(ret == -1){

2295

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

2296

strerror(errno));

2297

}

2298

free(fullname);

2299

}

2300

}

2301

2302

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

2303

free(direntries);

2304

if (numentries == -1){

2305

perror_plus("scandir");

2306

}

2307

ret = rmdir(tempdir);

2308

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

2309

perror_plus("rmdir");

2310

}

3123

if(tempdir != NULL){

3124

clean_dir_at(-1, tempdir, 0);

2311

3125

}

2312

3126

2313

3127

if(quit_now){