/mandos/release : revision 237.7.133

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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 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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*

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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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* WITHOUT ANY WARRANTY; without even the implied warranty of

24

22

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

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23

* General Public License for more details.

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*

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

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

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* along with this program. If not, see

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

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*

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

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30

*/

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32

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

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#ifndef _LARGEFILE_SOURCE

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#define _LARGEFILE_SOURCE

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#endif /* not _LARGEFILE_SOURCE */

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#endif

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#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif /* not _FILE_OFFSET_BITS */

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#endif

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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() */

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

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stdout, ferror(), remove() */

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

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

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

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strtof(), abort() */

49

48

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

50

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

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asprintf(), strncpy(), strsignal()

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*/

49

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

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

53

51

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

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52

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

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53

sockaddr_in6, PF_INET6,

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55

opendir(), DIR */

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

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

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inet_pton(), connect(),

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getnameinfo() */

62

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

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inet_pton(), connect() */

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

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60

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

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61

*/

65

62

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

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63

strtoimax() */

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

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

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

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66

program_invocation_short_name */

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

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

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73

*/

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74

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

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

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

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unlinkat() */

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

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

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

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

86

79

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

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80

argp_state, struct argp,

95

88

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

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WEXITSTATUS(), WTERMSIG() */

97

90

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

98

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

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

101

argz_count() */

102

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

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EAI_SYSTEM, gai_strerror() */

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105

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#ifdef __linux__

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93

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

148

135

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

149

136

char *connect_to = NULL;

150

137

const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

152

uid_t uid = 65534;

153

gid_t gid = 65534;

154

138

155

139

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

156

140

typedef struct server{

157

141

const char *ip;

158

in_port_t port;

142

uint16_t port;

159

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AvahiIfIndex if_index;

160

144

int af;

161

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struct timespec last_seen;

165

149

166

150

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

167

151

typedef struct {

152

AvahiSimplePoll *simple_poll;

168

153

AvahiServer *server;

169

154

gnutls_certificate_credentials_t cred;

170

155

unsigned int dh_bits;

172

157

const char *priority;

173

158

gpgme_ctx_t ctx;

174

159

server *current_server;

175

char *interfaces;

176

size_t interfaces_size;

177

160

} mandos_context;

178

161

179

/* global so signal handler can reach it*/

180

AvahiSimplePoll *simple_poll;

162

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

163

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

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.dh_bits = 1024, .priority = "SECURE256"

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

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.current_server = NULL };

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167

182

168

sig_atomic_t quit_now = 0;

183

169

int signal_received = 0;

191

177

perror(print_text);

192

178

}

193

179

194

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

180

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

195

181

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

196

182

va_list ap;

197

183

va_start (ap, format);

198

184

199

185

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

200

186

program_invocation_short_name));

201

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

187

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

202

188

}

203

189

204

190

/*

206

192

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

207

193

* "buffer_length" is how much is already used.

208

194

*/

209

__attribute__((nonnull, warn_unused_result))

210

195

size_t incbuffer(char **buffer, size_t buffer_length,

211

196

size_t buffer_capacity){

212

197

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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;

198

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

199

if(buffer == NULL){

219

200

return 0;

220

201

}

221

*buffer = new_buf;

222

202

buffer_capacity += BUFFER_SIZE;

223

203

}

224

204

return buffer_capacity;

225

205

}

226

206

227

207

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

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){

208

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

209

int af){

231

210

int ret;

232

211

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

233

212

if(new_server == NULL){

240

219

.af = af };

241

220

if(new_server->ip == NULL){

242

221

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);

258

222

return false;

259

223

}

260

224

/* Special case of first server */

261

if(*current_server == NULL){

225

if (mc.current_server == NULL){

262

226

new_server->next = new_server;

263

227

new_server->prev = new_server;

264

*current_server = new_server;

228

mc.current_server = new_server;

229

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

265

230

} else {

266

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

267

new_server->next = *current_server;

268

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

231

new_server->next = mc.current_server;

232

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

269

233

new_server->prev->next = new_server;

270

(*current_server)->prev = 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;

271

240

}

272

241

return true;

273

242

}

275

244

/*

276

245

* Initialize GPGME.

277

246

*/

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){

247

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

248

const char *tempdir){

283

249

gpgme_error_t rc;

284

250

gpgme_engine_info_t engine_info;

285

251

252

286

253

/*

287

254

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

288

255

*/

289

bool import_key(const char * const filename){

256

bool import_key(const char *filename){

290

257

int ret;

291

258

int fd;

292

259

gpgme_data_t pgp_data;

304

271

return false;

305

272

}

306

273

307

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

274

rc = gpgme_op_import(mc.ctx, pgp_data);

308

275

if(rc != GPG_ERR_NO_ERROR){

309

276

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

310

277

gpgme_strsource(rc), gpgme_strerror(rc));

311

278

return false;

312

279

}

313

280

314

ret = close(fd);

281

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

315

282

if(ret == -1){

316

283

perror_plus("close");

317

284

}

354

321

}

355

322

356

323

/* Create new GPGME "context" */

357

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

324

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

358

325

if(rc != GPG_ERR_NO_ERROR){

359

326

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

360

327

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

373

340

* Decrypt OpenPGP data.

374

341

* Returns -1 on error

375

342

*/

376

__attribute__((nonnull, warn_unused_result))

377

343

static ssize_t pgp_packet_decrypt(const char *cryptotext,

378

344

size_t crypto_size,

379

char **plaintext,

380

mandos_context *mc){

345

char **plaintext){

381

346

gpgme_data_t dh_crypto, dh_plain;

382

347

gpgme_error_t rc;

383

348

ssize_t ret;

409

374

410

375

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

411

376

data buffer */

412

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

377

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

413

378

if(rc != GPG_ERR_NO_ERROR){

414

379

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

415

380

gpgme_strsource(rc), gpgme_strerror(rc));

416

381

plaintext_length = -1;

417

382

if(debug){

418

383

gpgme_decrypt_result_t result;

419

result = gpgme_op_decrypt_result(mc->ctx);

384

result = gpgme_op_decrypt_result(mc.ctx);

420

385

if(result == NULL){

421

386

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

422

387

} else {

499

464

return plaintext_length;

500

465

}

501

466

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);

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;

513

473

}

514

474

515

475

/* GnuTLS log function callback */

516

__attribute__((nonnull))

517

476

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

518

477

const char* string){

519

478

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

520

479

}

521

480

522

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

523

481

static int init_gnutls_global(const char *pubkeyfilename,

524

const char *seckeyfilename,

525

const char *dhparamsfilename,

526

mandos_context *mc){

482

const char *seckeyfilename){

527

483

int ret;

528

unsigned int uret;

529

484

530

485

if(debug){

531

486

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

532

487

}

533

488

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

534

496

if(debug){

535

497

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

536

498

* - GnuTLS manual

540

502

}

541

503

542

504

/* OpenPGP credentials */

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

506

if(ret != GNUTLS_E_SUCCESS){

545

507

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

546

508

safer_gnutls_strerror(ret));

509

gnutls_global_deinit();

547

510

return -1;

548

511

}

549

512

555

518

}

556

519

557

520

ret = gnutls_certificate_set_openpgp_key_file

558

(mc->cred, pubkeyfilename, seckeyfilename,

521

(mc.cred, pubkeyfilename, seckeyfilename,

559

522

GNUTLS_OPENPGP_FMT_BASE64);

560

523

if(ret != GNUTLS_E_SUCCESS){

561

524

fprintf_plus(stderr,

567

530

}

568

531

569

532

/* GnuTLS server initialization */

570

ret = gnutls_dh_params_init(&mc->dh_params);

533

ret = gnutls_dh_params_init(&mc.dh_params);

571

534

if(ret != GNUTLS_E_SUCCESS){

572

535

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

573

536

" initialization: %s\n",

574

537

safer_gnutls_strerror(ret));

575

538

goto globalfail;

576

539

}

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

close(dhpfile);

617

if(params.data == NULL){

618

dhparamsfilename = NULL;

619

}

620

if(dhparamsfilename == NULL){

621

break;

622

}

623

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

624

GNUTLS_X509_FMT_PEM);

625

if(ret != GNUTLS_E_SUCCESS){

626

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

627

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

628

safer_gnutls_strerror(ret));

629

dhparamsfilename = NULL;

630

}

631

free(params.data);

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

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

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

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

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

751

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

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);

752

548

753

549

return 0;

754

550

755

551

globalfail:

756

552

757

gnutls_certificate_free_credentials(mc->cred);

758

gnutls_dh_params_deinit(mc->dh_params);

553

gnutls_certificate_free_credentials(mc.cred);

554

gnutls_global_deinit();

555

gnutls_dh_params_deinit(mc.dh_params);

759

556

return -1;

760

557

}

761

558

762

__attribute__((nonnull, warn_unused_result))

763

static int init_gnutls_session(gnutls_session_t *session,

764

mandos_context *mc){

559

static int init_gnutls_session(gnutls_session_t *session){

765

560

int ret;

766

561

/* GnuTLS session creation */

767

562

do {

779

574

{

780

575

const char *err;

781

576

do {

782

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

577

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

783

578

if(quit_now){

784

579

gnutls_deinit(*session);

785

580

return -1;

796

591

797

592

do {

798

593

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

799

mc->cred);

594

mc.cred);

800

595

if(quit_now){

801

596

gnutls_deinit(*session);

802

597

return -1;

812

607

/* ignore client certificate if any. */

813

608

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

814

609

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

611

815

612

return 0;

816

613

}

817

614

819

616

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

820

617

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

821

618

822

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

823

__attribute__((warn_unused_result))

824

int raise_privileges(void){

825

int old_errno = errno;

826

int ret = 0;

827

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

828

ret = errno;

829

}

830

errno = old_errno;

831

return ret;

832

}

833

834

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

835

__attribute__((warn_unused_result))

836

int raise_privileges_permanently(void){

837

int old_errno = errno;

838

int ret = raise_privileges();

839

if(ret != 0){

840

errno = old_errno;

841

return ret;

842

}

843

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

844

ret = errno;

845

}

846

errno = old_errno;

847

return ret;

848

}

849

850

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

851

__attribute__((warn_unused_result))

852

int lower_privileges(void){

853

int old_errno = errno;

854

int ret = 0;

855

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

856

ret = errno;

857

}

858

errno = old_errno;

859

return ret;

860

}

861

862

/* Lower privileges permanently */

863

__attribute__((warn_unused_result))

864

int lower_privileges_permanently(void){

865

int old_errno = errno;

866

int ret = 0;

867

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

868

ret = errno;

869

}

870

errno = old_errno;

871

return ret;

872

}

873

874

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

875

__attribute__((nonnull, warn_unused_result))

876

static bool add_delete_local_route(const bool add,

877

const char *address,

878

AvahiIfIndex if_index){

879

int ret;

880

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

881

char add_arg[] = "add";

882

char delete_arg[] = "delete";

883

char debug_flag[] = "--debug";

884

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

885

if(pluginhelperdir == NULL){

886

if(debug){

887

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

888

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

889

}

890

return false;

891

}

892

893

char interface[IF_NAMESIZE];

894

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

895

perror_plus("if_indextoname");

896

return false;

897

}

898

899

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

900

if(devnull == -1){

901

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

902

return false;

903

}

904

pid_t pid = fork();

905

if(pid == 0){

906

/* Child */

907

/* Raise privileges */

908

errno = raise_privileges_permanently();

909

if(errno != 0){

910

perror_plus("Failed to raise privileges");

911

/* _exit(EX_NOPERM); */

912

} else {

913

/* Set group */

914

errno = 0;

915

ret = setgid(0);

916

if(ret == -1){

917

perror_plus("setgid");

918

_exit(EX_NOPERM);

919

}

920

/* Reset supplementary groups */

921

errno = 0;

922

ret = setgroups(0, NULL);

923

if(ret == -1){

924

perror_plus("setgroups");

925

_exit(EX_NOPERM);

926

}

927

}

928

ret = dup2(devnull, STDIN_FILENO);

929

if(ret == -1){

930

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

931

_exit(EX_OSERR);

932

}

933

ret = close(devnull);

934

if(ret == -1){

935

perror_plus("close");

936

_exit(EX_OSERR);

937

}

938

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

939

if(ret == -1){

940

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

941

_exit(EX_OSERR);

942

}

943

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

944

O_RDONLY

945

| O_DIRECTORY

946

| O_PATH

947

| O_CLOEXEC));

948

if(helperdir_fd == -1){

949

perror_plus("open");

950

_exit(EX_UNAVAILABLE);

951

}

952

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

953

helper, O_RDONLY));

954

if(helper_fd == -1){

955

perror_plus("openat");

956

close(helperdir_fd);

957

_exit(EX_UNAVAILABLE);

958

}

959

close(helperdir_fd);

960

#ifdef __GNUC__

961

#pragma GCC diagnostic push

962

#pragma GCC diagnostic ignored "-Wcast-qual"

963

#endif

964

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

965

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

966

interface, debug ? debug_flag : NULL, NULL },

967

environ) == -1){

968

#ifdef __GNUC__

969

#pragma GCC diagnostic pop

970

#endif

971

perror_plus("fexecve");

972

_exit(EXIT_FAILURE);

973

}

974

}

975

if(pid == -1){

976

perror_plus("fork");

977

return false;

978

}

979

int status;

980

pid_t pret = -1;

981

errno = 0;

982

do {

983

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

984

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

985

int errno_raising = 0;

986

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

987

errno_raising = errno;

988

perror_plus("Failed to raise privileges in order to"

989

" kill helper program");

990

}

991

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

992

perror_plus("kill");

993

}

994

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

995

perror_plus("Failed to lower privileges after killing"

996

" helper program");

997

}

998

return false;

999

}

1000

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

1001

if(pret == -1){

1002

perror_plus("waitpid");

1003

return false;

1004

}

1005

if(WIFEXITED(status)){

1006

if(WEXITSTATUS(status) != 0){

1007

fprintf_plus(stderr, "Error: iprouteadddel exited"

1008

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

1009

return false;

1010

}

1011

return true;

1012

}

1013

if(WIFSIGNALED(status)){

1014

fprintf_plus(stderr, "Error: iprouteadddel died by"

1015

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

1016

return false;

1017

}

1018

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

1019

return false;

1020

}

1021

1022

__attribute__((nonnull, warn_unused_result))

1023

static bool add_local_route(const char *address,

1024

AvahiIfIndex if_index){

1025

if(debug){

1026

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

1027

}

1028

return add_delete_local_route(true, address, if_index);

1029

}

1030

1031

__attribute__((nonnull, warn_unused_result))

1032

static bool delete_local_route(const char *address,

1033

AvahiIfIndex if_index){

1034

if(debug){

1035

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

1036

}

1037

return add_delete_local_route(false, address, if_index);

1038

}

1039

1040

619

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

1042

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

620

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

1043

621

AvahiIfIndex if_index,

1044

int af, mandos_context *mc){

622

int af){

1045

623

int ret, tcp_sd = -1;

1046

624

ssize_t sret;

1047

struct sockaddr_storage to;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

1048

629

char *buffer = NULL;

1049

630

char *decrypted_buffer = NULL;

1050

631

size_t buffer_length = 0;

1053

634

int retval = -1;

1054

635

gnutls_session_t session;

1055

636

int pf; /* Protocol family */

1056

bool route_added = false;

1057

637

1058

638

errno = 0;

1059

639

1075

655

return -1;

1076

656

}

1077

657

1078

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

1079

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

1080

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

1081

bool match = false;

1082

{

1083

char *interface = NULL;

1084

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

1085

mc->interfaces_size,

1086

interface))){

1087

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

1088

match = true;

1089

break;

1090

}

1091

}

1092

}

1093

if(not match){

1094

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

1095

connect to the server */

1096

if(debug){

1097

char interface[IF_NAMESIZE];

1098

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

1099

perror_plus("if_indextoname");

1100

} else {

1101

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

1102

" \"%s\"\n",

1103

if_indextoname((unsigned int)if_index,

1104

interface));

1105

}

1106

}

1107

return -1;

1108

}

1109

}

1110

1111

ret = init_gnutls_session(&session, mc);

658

ret = init_gnutls_session(&session);

1112

659

if(ret != 0){

1113

660

return -1;

1114

661

}

1115

662

1116

663

if(debug){

1117

664

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

1118

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

665

PRIu16 "\n", ip, port);

1119

666

}

1120

667

1121

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

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1122

669

if(tcp_sd < 0){

1123

670

int e = errno;

1124

671

perror_plus("socket");

1131

678

goto mandos_end;

1132

679

}

1133

680

681

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

1134

682

if(af == AF_INET6){

1135

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

1136

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

1137

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

683

to.in6.sin6_family = (sa_family_t)af;

684

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

1138

685

} else { /* IPv4 */

1139

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

1140

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

1141

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

686

to.in.sin_family = (sa_family_t)af;

687

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

1142

688

}

1143

689

if(ret < 0 ){

1144

690

int e = errno;

1153

699

goto mandos_end;

1154

700

}

1155

701

if(af == AF_INET6){

1156

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

1157

if(IN6_IS_ADDR_LINKLOCAL

1158

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

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

709

if(if_index == AVAHI_IF_UNSPEC){

1160

710

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

1161

711

" incomplete without a network interface\n");

1163

713

goto mandos_end;

1164

714

}

1165

715

/* Set the network interface number as scope */

1166

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

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1167

717

}

1168

718

} else {

1169

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

719

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

720

-Wconversion and

721

-Wunreachable-code */

1170

722

}

1171

723

1172

724

if(quit_now){

1180

732

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

1181

733

perror_plus("if_indextoname");

1182

734

} else {

1183

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

1184

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

735

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

736

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

1185

737

}

1186

738

} else {

1187

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

1188

ip, (uintmax_t)port);

739

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

740

ip, port);

1189

741

}

1190

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1191

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1192

if(af == AF_INET6){

1193

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

1194

sizeof(struct sockaddr_in6),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

} else {

1198

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

1199

sizeof(struct sockaddr_in),

1200

addrstr, sizeof(addrstr), NULL, 0,

1201

NI_NUMERICHOST);

1202

}

1203

if(ret == EAI_SYSTEM){

1204

perror_plus("getnameinfo");

1205

} else if(ret != 0) {

1206

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

1207

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

1208

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

1209

}

1210

}

1211

1212

if(quit_now){

1213

errno = EINTR;

1214

goto mandos_end;

1215

}

1216

1217

while(true){

1218

if(af == AF_INET6){

1219

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

1220

sizeof(struct sockaddr_in6));

1221

} else {

1222

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

1223

sizeof(struct sockaddr_in));

1224

}

1225

if(ret < 0){

1226

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

1227

and if_index != AVAHI_IF_UNSPEC

1228

and connect_to == NULL

1229

and not route_added and

1230

((af == AF_INET6 and not

1231

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1232

&to)->sin6_addr)))

1233

or (af == AF_INET and

1234

/* Not a a IPv4LL address */

1235

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

1236

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

1237

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

1238

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

1239

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

1240

connect to a Mandos server announced by Avahi on a server

1241

host with a global address. Work around this by retrying

1242

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

1243

1244

Avahi bug reference:

1245

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

1246

https://bugs.debian.org/587961

1247

*/

1248

if(debug){

1249

fprintf_plus(stderr, "Mandos server unreachable, trying"

1250

" direct route\n");

1251

}

1252

int e = errno;

1253

route_added = add_local_route(ip, if_index);

1254

if(route_added){

1255

continue;

1256

}

1257

errno = e;

1258

}

1259

if(errno != ECONNREFUSED or debug){

1260

int e = errno;

1261

perror_plus("connect");

1262

errno = e;

1263

}

1264

goto mandos_end;

1265

}

1266

1267

if(quit_now){

1268

errno = EINTR;

1269

goto mandos_end;

1270

}

1271

break;

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;

1272

783

}

1273

784

1274

785

const char *out = mandos_protocol_version;

1310

821

goto mandos_end;

1311

822

}

1312

823

1313

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

1314

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

1315

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

1316

gnutls_transport_set_ptr(session,

1317

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

824

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

825

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1318

826

1319

827

if(quit_now){

1320

828

errno = EINTR;

1425

933

if(buffer_length > 0){

1426

934

ssize_t decrypted_buffer_size;

1427

935

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1428

&decrypted_buffer, mc);

936

&decrypted_buffer);

1429

937

if(decrypted_buffer_size >= 0){

1430

938

1431

clearerr(stdout);

1432

939

written = 0;

1433

940

while(written < (size_t) decrypted_buffer_size){

1434

941

if(quit_now){

1450

957

}

1451

958

written += (size_t)ret;

1452

959

}

1453

ret = fflush(stdout);

1454

if(ret != 0){

1455

int e = errno;

1456

if(debug){

1457

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

1458

strerror(errno));

1459

}

1460

errno = e;

1461

goto mandos_end;

1462

}

1463

960

retval = 0;

1464

961

}

1465

962

}

1468

965

1469

966

mandos_end:

1470

967

{

1471

if(route_added){

1472

if(not delete_local_route(ip, if_index)){

1473

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

1474

" interface %d", ip, if_index);

1475

}

1476

}

1477

968

int e = errno;

1478

969

free(decrypted_buffer);

1479

970

free(buffer);

1480

971

if(tcp_sd >= 0){

1481

ret = close(tcp_sd);

972

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

1482

973

}

1483

974

if(ret == -1){

1484

975

if(e == 0){

1509

1000

AVAHI_GCC_UNUSED AvahiStringList *txt,

1510

1001

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1511

1002

flags,

1512

void *mc){

1513

if(r == NULL){

1514

return;

1515

}

1003

AVAHI_GCC_UNUSED void* userdata){

1004

assert(r);

1516

1005

1517

1006

/* Called whenever a service has been resolved successfully or

1518

1007

timed out */

1519

1008

1520

1009

if(quit_now){

1521

avahi_s_service_resolver_free(r);

1522

1010

return;

1523

1011

}

1524

1012

1528

1016

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

1529

1017

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

1530

1018

domain,

1531

avahi_strerror(avahi_server_errno

1532

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

1019

avahi_strerror(avahi_server_errno(mc.server)));

1533

1020

break;

1534

1021

1535

1022

case AVAHI_RESOLVER_FOUND:

1541

1028

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

1542

1029

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

1543

1030

}

1544

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

1545

interface,

1546

avahi_proto_to_af(proto),

1547

mc);

1031

int ret = start_mandos_communication(ip, port, interface,

1032

avahi_proto_to_af(proto));

1548

1033

if(ret == 0){

1549

avahi_simple_poll_quit(simple_poll);

1034

avahi_simple_poll_quit(mc.simple_poll);

1550

1035

} else {

1551

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

1552

avahi_proto_to_af(proto),

1553

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

1036

if(not add_server(ip, port, interface,

1037

avahi_proto_to_af(proto))){

1554

1038

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

1555

1039

" list\n", name);

1556

1040

}

1569

1053

const char *domain,

1570

1054

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1571

1055

flags,

1572

void *mc){

1573

if(b == NULL){

1574

return;

1575

}

1056

AVAHI_GCC_UNUSED void* userdata){

1057

assert(b);

1576

1058

1577

1059

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

1578

1060

is removed from the LAN */

1586

1068

case AVAHI_BROWSER_FAILURE:

1587

1069

1588

1070

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

1589

avahi_strerror(avahi_server_errno

1590

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

1591

avahi_simple_poll_quit(simple_poll);

1071

avahi_strerror(avahi_server_errno(mc.server)));

1072

avahi_simple_poll_quit(mc.simple_poll);

1592

1073

return;

1593

1074

1594

1075

case AVAHI_BROWSER_NEW:

1597

1078

the callback function is called the Avahi server will free the

1598

1079

resolver for us. */

1599

1080

1600

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

1601

interface, protocol, name, type,

1602

domain, protocol, 0,

1603

resolve_callback, mc) == NULL)

1081

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

1082

name, type, domain, protocol, 0,

1083

resolve_callback, NULL) == NULL)

1604

1084

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

1605

1085

" %s\n", name,

1606

avahi_strerror(avahi_server_errno

1607

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

1086

avahi_strerror(avahi_server_errno(mc.server)));

1608

1087

break;

1609

1088

1610

1089

case AVAHI_BROWSER_REMOVE:

1629

1108

signal_received = sig;

1630

1109

int old_errno = errno;

1631

1110

/* set main loop to exit */

1632

if(simple_poll != NULL){

1633

avahi_simple_poll_quit(simple_poll);

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1634

1113

}

1635

1114

errno = old_errno;

1636

1115

}

1637

1116

1638

__attribute__((nonnull, warn_unused_result))

1639

1117

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

1640

1118

int ret;

1641

int old_errno;

1642

1119

1643

1120

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

1644

1121

if(s < 0){

1645

old_errno = errno;

1646

1122

perror_plus("socket");

1647

errno = old_errno;

1648

1123

return false;

1649

1124

}

1650

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

1651

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

1125

strcpy(ifr->ifr_name, ifname);

1652

1126

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1653

1127

if(ret == -1){

1654

1128

if(debug){

1655

old_errno = errno;

1656

1129

perror_plus("ioctl SIOCGIFFLAGS");

1657

errno = old_errno;

1658

1130

}

1659

close(s);

1660

1131

return false;

1661

1132

}

1662

close(s);

1663

1133

return true;

1664

1134

}

1665

1135

1666

__attribute__((nonnull, warn_unused_result))

1667

1136

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

1668

1137

1669

1138

/* Reject the loopback device */

1711

1180

* corresponds to an acceptable network device.

1712

1181

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

1713

1182

*/

1714

__attribute__((nonnull, warn_unused_result))

1715

1183

int good_interface(const struct dirent *if_entry){

1716

1184

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

1717

1185

return 0;

1733

1201

}

1734

1202

1735

1203

/*

1736

* This function determines if a network interface is up.

1737

*/

1738

__attribute__((nonnull, warn_unused_result))

1739

bool interface_is_up(const char *interface){

1740

struct ifreq ifr;

1741

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

1742

if(debug){

1743

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

1744

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

1745

}

1746

return false;

1747

}

1748

1749

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

1750

}

1751

1752

/*

1753

* This function determines if a network interface is running

1754

*/

1755

__attribute__((nonnull, warn_unused_result))

1756

bool interface_is_running(const char *interface){

1757

struct ifreq ifr;

1758

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

1759

if(debug){

1760

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

1761

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

1762

}

1763

return false;

1764

}

1765

1766

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

1767

}

1768

1769

__attribute__((nonnull, pure, warn_unused_result))

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

1770

1246

int notdotentries(const struct dirent *direntry){

1771

1247

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

1772

1248

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

1779

1255

}

1780

1256

1781

1257

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

1782

__attribute__((nonnull, warn_unused_result))

1783

1258

int runnable_hook(const struct dirent *direntry){

1784

1259

int ret;

1785

1260

size_t sret;

1793

1268

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

1794

1269

"abcdefghijklmnopqrstuvwxyz"

1795

1270

"0123456789"

1796

"_.-");

1271

"_-");

1797

1272

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

1798

1273

/* Contains non-allowed characters */

1799

1274

if(debug){

1803

1278

return 0;

1804

1279

}

1805

1280

1806

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

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);

1807

1289

if(ret == -1){

1808

1290

if(debug){

1809

1291

perror_plus("Could not stat hook");

1833

1315

return 1;

1834

1316

}

1835

1317

1836

__attribute__((nonnull, warn_unused_result))

1837

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1838

mandos_context *mc){

1318

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1839

1319

int ret;

1840

1320

struct timespec now;

1841

1321

struct timespec waited_time;

1842

1322

intmax_t block_time;

1843

1323

1844

1324

while(true){

1845

if(mc->current_server == NULL){

1846

if(debug){

1325

if(mc.current_server == NULL){

1326

if (debug){

1847

1327

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

1848

1328

" No timeout!\n");

1849

1329

}

1850

1330

ret = avahi_simple_poll_iterate(s, -1);

1851

1331

} else {

1852

if(debug){

1332

if (debug){

1853

1333

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

1854

1334

" it, or wait\n");

1855

1335

}

1862

1342

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

1863

1343

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

1864

1344

waited_time.tv_sec = (now.tv_sec

1865

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

1345

- mc.current_server->last_seen.tv_sec);

1866

1346

waited_time.tv_nsec = (now.tv_nsec

1867

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

1347

- mc.current_server->last_seen.tv_nsec);

1868

1348

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

1869

1349

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

1870

1350

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

1872

1352

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

1873

1353

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

1874

1354

1875

if(debug){

1355

if (debug){

1876

1356

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

1877

1357

block_time);

1878

1358

}

1879

1359

1880

1360

if(block_time <= 0){

1881

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

1882

mc->current_server->port,

1883

mc->current_server->if_index,

1884

mc->current_server->af, mc);

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);

1885

1365

if(ret == 0){

1886

avahi_simple_poll_quit(s);

1366

avahi_simple_poll_quit(mc.simple_poll);

1887

1367

return 0;

1888

1368

}

1889

1369

ret = clock_gettime(CLOCK_MONOTONIC,

1890

&mc->current_server->last_seen);

1370

&mc.current_server->last_seen);

1891

1371

if(ret == -1){

1892

1372

perror_plus("clock_gettime");

1893

1373

return -1;

1894

1374

}

1895

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

1375

mc.current_server = mc.current_server->next;

1896

1376

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

1897

1377

servers, but don't block */

1898

1378

}

1900

1380

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

1901

1381

}

1902

1382

if(ret != 0){

1903

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

1383

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

1904

1384

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

1905

1385

}

1906

1386

}

1907

1387

}

1908

1388

}

1909

1389

1910

__attribute__((nonnull))

1911

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

1390

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

1912

1391

const float delay){

1913

struct dirent **direntries = NULL;

1914

if(hookdir_fd == -1){

1915

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1916

| O_CLOEXEC);

1917

if(hookdir_fd == -1){

1918

if(errno == ENOENT){

1919

if(debug){

1920

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

1921

" found\n", hookdir);

1922

}

1923

} else {

1924

perror_plus("open");

1925

}

1926

return;

1927

}

1928

}

1929

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

1930

if(devnull == -1){

1931

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

1932

return;

1933

}

1934

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

1935

runnable_hook, alphasort);

1392

struct dirent **direntries;

1393

struct dirent *direntry;

1394

int ret;

1395

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

1396

alphasort);

1936

1397

if(numhooks == -1){

1937

1398

perror_plus("scandir");

1938

close(devnull);

1939

return;

1940

}

1941

struct dirent *direntry;

1942

int ret;

1943

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

1944

direntry = direntries[i];

1945

if(debug){

1946

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

1947

direntry->d_name);

1948

}

1949

pid_t hook_pid = fork();

1950

if(hook_pid == 0){

1951

/* Child */

1952

/* Raise privileges */

1953

errno = raise_privileges_permanently();

1954

if(errno != 0){

1955

perror_plus("Failed to raise privileges");

1956

_exit(EX_NOPERM);

1957

}

1958

/* Set group */

1959

errno = 0;

1960

ret = setgid(0);

1961

if(ret == -1){

1962

perror_plus("setgid");

1963

_exit(EX_NOPERM);

1964

}

1965

/* Reset supplementary groups */

1966

errno = 0;

1967

ret = setgroups(0, NULL);

1968

if(ret == -1){

1969

perror_plus("setgroups");

1970

_exit(EX_NOPERM);

1971

}

1972

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

1973

if(ret == -1){

1974

perror_plus("setenv");

1975

_exit(EX_OSERR);

1976

}

1977

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

1978

if(ret == -1){

1979

perror_plus("setenv");

1980

_exit(EX_OSERR);

1981

}

1982

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

1983

if(ret == -1){

1984

perror_plus("setenv");

1985

_exit(EX_OSERR);

1986

}

1987

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

1988

if(ret == -1){

1989

perror_plus("setenv");

1990

_exit(EX_OSERR);

1991

}

1992

char *delaystring;

1993

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

1994

if(ret == -1){

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){

1995

1406

perror_plus("asprintf");

1996

_exit(EX_OSERR);

1997

}

1998

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

1999

if(ret == -1){

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

}

2000

1475

free(delaystring);

2001

perror_plus("setenv");

2002

_exit(EX_OSERR);

2003

}

2004

free(delaystring);

2005

if(connect_to != NULL){

2006

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

2007

if(ret == -1){

2008

perror_plus("setenv");

2009

_exit(EX_OSERR);

2010

}

2011

}

2012

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

2013

direntry->d_name,

2014

O_RDONLY));

2015

if(hook_fd == -1){

2016

perror_plus("openat");

2017

_exit(EXIT_FAILURE);

2018

}

2019

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

2020

perror_plus("close");

2021

_exit(EXIT_FAILURE);

2022

}

2023

ret = dup2(devnull, STDIN_FILENO);

2024

if(ret == -1){

2025

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

2026

_exit(EX_OSERR);

2027

}

2028

ret = close(devnull);

2029

if(ret == -1){

2030

perror_plus("close");

2031

_exit(EX_OSERR);

2032

}

2033

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2034

if(ret == -1){

2035

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

2036

_exit(EX_OSERR);

2037

}

2038

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

2039

environ) == -1){

2040

perror_plus("fexecve");

2041

_exit(EXIT_FAILURE);

2042

}

2043

} else {

2044

if(hook_pid == -1){

2045

perror_plus("fork");

2046

free(direntry);

2047

continue;

2048

}

2049

int status;

2050

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

2051

perror_plus("waitpid");

2052

free(direntry);

2053

continue;

2054

}

2055

if(WIFEXITED(status)){

2056

if(WEXITSTATUS(status) != 0){

2057

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

2058

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

2059

WEXITSTATUS(status));

2060

free(direntry);

2061

continue;

2062

}

2063

} else if(WIFSIGNALED(status)){

2064

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

2065

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

2066

WTERMSIG(status));

2067

free(direntry);

2068

continue;

2069

} else {

2070

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

2071

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

2072

free(direntry);

2073

continue;

2074

}

2075

}

2076

if(debug){

2077

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

2078

direntry->d_name);

2079

}

2080

free(direntry);

2081

}

2082

free(direntries);

2083

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

2084

perror_plus("close");

2085

} else {

2086

hookdir_fd = -1;

2087

}

2088

close(devnull);

2089

}

2090

2091

__attribute__((nonnull, warn_unused_result))

2092

int bring_up_interface(const char *const interface,

2093

const float delay){

2094

int old_errno = errno;

2095

int ret;

2096

struct ifreq network;

2097

unsigned int if_index = if_nametoindex(interface);

2098

if(if_index == 0){

2099

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

2100

errno = old_errno;

2101

return ENXIO;

2102

}

2103

2104

if(quit_now){

2105

errno = old_errno;

2106

return EINTR;

2107

}

2108

2109

if(not interface_is_up(interface)){

2110

int ret_errno = 0;

2111

int ioctl_errno = 0;

2112

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

2113

ret_errno = errno;

2114

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

2115

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

2116

errno = old_errno;

2117

return ret_errno;

2118

}

2119

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

2120

2121

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

2122

if(sd == -1){

2123

ret_errno = errno;

2124

perror_plus("socket");

2125

errno = old_errno;

2126

return ret_errno;

2127

}

2128

2129

if(quit_now){

2130

ret = close(sd);

2131

if(ret == -1){

2132

perror_plus("close");

2133

}

2134

errno = old_errno;

2135

return EINTR;

2136

}

2137

2138

if(debug){

2139

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

2140

interface);

2141

}

2142

2143

/* Raise privileges */

2144

ret_errno = raise_privileges();

2145

if(ret_errno != 0){

2146

errno = ret_errno;

2147

perror_plus("Failed to raise privileges");

2148

}

2149

2150

#ifdef __linux__

2151

int ret_linux;

2152

bool restore_loglevel = false;

2153

if(ret_errno == 0){

2154

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2155

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

2156

ret_linux = klogctl(8, NULL, 5);

2157

if(ret_linux == -1){

2158

perror_plus("klogctl");

2159

} else {

2160

restore_loglevel = true;

2161

}

2162

}

2163

#endif /* __linux__ */

2164

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

2165

ioctl_errno = errno;

2166

#ifdef __linux__

2167

if(restore_loglevel){

2168

ret_linux = klogctl(7, NULL, 0);

2169

if(ret_linux == -1){

2170

perror_plus("klogctl");

2171

}

2172

}

2173

#endif /* __linux__ */

2174

2175

/* If raise_privileges() succeeded above */

2176

if(ret_errno == 0){

2177

/* Lower privileges */

2178

ret_errno = lower_privileges();

2179

if(ret_errno != 0){

2180

errno = ret_errno;

2181

perror_plus("Failed to lower privileges");

2182

}

2183

}

2184

2185

/* Close the socket */

2186

ret = close(sd);

2187

if(ret == -1){

2188

perror_plus("close");

2189

}

2190

2191

if(ret_setflags == -1){

2192

errno = ioctl_errno;

2193

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2194

errno = old_errno;

2195

return ioctl_errno;

2196

}

2197

} else if(debug){

2198

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

2199

interface);

2200

}

2201

2202

/* Sleep checking until interface is running.

2203

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

2204

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

2205

if(interface_is_running(interface)){

2206

break;

2207

}

2208

struct timespec sleeptime = { .tv_nsec = 250000000 };

2209

ret = nanosleep(&sleeptime, NULL);

2210

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

2211

perror_plus("nanosleep");

2212

}

2213

}

2214

2215

errno = old_errno;

2216

return 0;

2217

}

2218

2219

__attribute__((nonnull, warn_unused_result))

2220

int take_down_interface(const char *const interface){

2221

int old_errno = errno;

2222

struct ifreq network;

2223

unsigned int if_index = if_nametoindex(interface);

2224

if(if_index == 0){

2225

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

2226

errno = old_errno;

2227

return ENXIO;

2228

}

2229

if(interface_is_up(interface)){

2230

int ret_errno = 0;

2231

int ioctl_errno = 0;

2232

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

2233

ret_errno = errno;

2234

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

2235

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

2236

errno = old_errno;

2237

return ret_errno;

2238

}

2239

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

2240

2241

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

2242

if(sd == -1){

2243

ret_errno = errno;

2244

perror_plus("socket");

2245

errno = old_errno;

2246

return ret_errno;

2247

}

2248

2249

if(debug){

2250

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

2251

interface);

2252

}

2253

2254

/* Raise privileges */

2255

ret_errno = raise_privileges();

2256

if(ret_errno != 0){

2257

errno = ret_errno;

2258

perror_plus("Failed to raise privileges");

2259

}

2260

2261

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

2262

ioctl_errno = errno;

2263

2264

/* If raise_privileges() succeeded above */

2265

if(ret_errno == 0){

2266

/* Lower privileges */

2267

ret_errno = lower_privileges();

2268

if(ret_errno != 0){

2269

errno = ret_errno;

2270

perror_plus("Failed to lower privileges");

2271

}

2272

}

2273

2274

/* Close the socket */

2275

int ret = close(sd);

2276

if(ret == -1){

2277

perror_plus("close");

2278

}

2279

2280

if(ret_setflags == -1){

2281

errno = ioctl_errno;

2282

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2283

errno = old_errno;

2284

return ioctl_errno;

2285

}

2286

} else if(debug){

2287

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

2288

interface);

2289

}

2290

2291

errno = old_errno;

2292

return 0;

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;

2293

1524

}

2294

1525

2295

1526

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

2296

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

2297

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

2298

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

2299

.current_server = NULL, .interfaces = NULL,

2300

.interfaces_size = 0 };

2301

1527

AvahiSServiceBrowser *sb = NULL;

2302

error_t ret_errno;

1528

int error;

2303

1529

int ret;

2304

1530

intmax_t tmpmax;

2305

1531

char *tmp;

2306

1532

int exitcode = EXIT_SUCCESS;

2307

char *interfaces_to_take_down = NULL;

2308

size_t interfaces_to_take_down_size = 0;

2309

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

2310

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

2311

char *tempdir = NULL;

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;

2312

1541

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2313

1542

const char *seckey = PATHDIR "/" SECKEY;

2314

1543

const char *pubkey = PATHDIR "/" PUBKEY;

2315

const char *dh_params_file = NULL;

2316

char *interfaces_hooks = NULL;

2317

1544

2318

1545

bool gnutls_initialized = false;

2319

1546

bool gpgme_initialized = false;

2371

1598

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

2372

1599

" Diffie-Hellman key exchange",

2373

1600

.group = 2 },

2374

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

2375

.arg = "FILE",

2376

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

2377

" for the Diffie-Hellman key exchange",

2378

.group = 2 },

2379

1601

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

2380

1602

.arg = "STRING",

2381

1603

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

2415

1637

connect_to = arg;

2416

1638

break;

2417

1639

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

2418

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

2419

arg, (int)',');

2420

if(ret_errno != 0){

2421

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

2422

}

1640

interface = arg;

2423

1641

break;

2424

1642

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

2425

1643

seckey = arg;

2436

1654

}

2437

1655

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

2438

1656

break;

2439

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

2440

dh_params_file = arg;

2441

break;

2442

1657

case 130: /* --priority */

2443

1658

mc.priority = arg;

2444

1659

break;

2484

1699

.args_doc = "",

2485

1700

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

2486

1701

" passwords from a Mandos server" };

2487

ret_errno = argp_parse(&argp, argc, argv,

2488

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2489

switch(ret_errno){

1702

ret = argp_parse(&argp, argc, argv,

1703

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1704

switch(ret){

2490

1705

case 0:

2491

1706

break;

2492

1707

case ENOMEM:

2493

1708

default:

2494

errno = ret_errno;

1709

errno = ret;

2495

1710

perror_plus("argp_parse");

2496

1711

exitcode = EX_OSERR;

2497

1712

goto end;

2500

1715

goto end;

2501

1716

}

2502

1717

}

2503

1718

2504

1719

{

2505

1720

/* Work around Debian bug #633582:

2506

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

1721

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

2507

1722

2508

/* Re-raise privileges */

2509

ret = raise_privileges();

2510

if(ret != 0){

2511

errno = ret;

2512

perror_plus("Failed to raise privileges");

1723

/* Re-raise priviliges */

1724

errno = 0;

1725

ret = seteuid(0);

1726

if(ret == -1){

1727

perror_plus("seteuid");

2513

1728

} else {

2514

1729

struct stat st;

2515

1730

2530

1745

}

2531

1746

}

2532

1747

}

2533

close(seckey_fd);

1748

TEMP_FAILURE_RETRY(close(seckey_fd));

2534

1749

}

2535

1750

}

2536

1751

2537

1752

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

2538

1753

int pubkey_fd = open(pubkey, O_RDONLY);

2539

1754

if(pubkey_fd == -1){

2551

1766

}

2552

1767

}

2553

1768

}

2554

close(pubkey_fd);

2555

}

2556

}

2557

2558

if(dh_params_file != NULL

2559

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

2560

int dhparams_fd = open(dh_params_file, O_RDONLY);

2561

if(dhparams_fd == -1){

2562

perror_plus("open");

2563

} else {

2564

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

2565

if(ret == -1){

2566

perror_plus("fstat");

2567

} else {

2568

if(S_ISREG(st.st_mode)

2569

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

2570

ret = fchown(dhparams_fd, uid, gid);

2571

if(ret == -1){

2572

perror_plus("fchown");

2573

}

2574

}

2575

}

2576

close(dhparams_fd);

2577

}

2578

}

2579

1769

TEMP_FAILURE_RETRY(close(pubkey_fd));

1770

}

1771

}

1772

2580

1773

/* Lower privileges */

2581

ret = lower_privileges();

2582

if(ret != 0){

2583

errno = ret;

2584

perror_plus("Failed to lower privileges");

2585

}

2586

}

2587

}

2588

2589

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

2590

{

2591

char *interface = NULL;

2592

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

2593

interface))){

2594

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

2595

and if_nametoindex(interface) == 0){

2596

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

2597

fprintf_plus(stderr, "Not using nonexisting interface"

2598

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

2599

}

2600

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

2601

interface = NULL;

1774

errno = 0;

1775

ret = seteuid(uid);

1776

if(ret == -1){

1777

perror_plus("seteuid");

2602

1778

}

2603

1779

}

2604

1780

}

2605

1781

2606

1782

/* Run network hooks */

2607

{

2608

if(mc.interfaces != NULL){

2609

interfaces_hooks = malloc(mc.interfaces_size);

2610

if(interfaces_hooks == NULL){

2611

perror_plus("malloc");

2612

goto end;

2613

}

2614

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

2615

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

2616

}

2617

run_network_hooks("start", interfaces_hooks != NULL ?

2618

interfaces_hooks : "", delay);

1783

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

1784

goto end;

2619

1785

}

2620

1786

2621

1787

if(not debug){

2622

1788

avahi_set_log_function(empty_log);

2623

1789

}

2624

1790

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

2625

1823

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

2626

1824

from the signal handler */

2627

1825

/* Initialize the pseudo-RNG for Avahi */

2628

1826

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

2629

simple_poll = avahi_simple_poll_new();

2630

if(simple_poll == NULL){

1827

mc.simple_poll = avahi_simple_poll_new();

1828

if(mc.simple_poll == NULL){

2631

1829

fprintf_plus(stderr,

2632

1830

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

2633

1831

exitcode = EX_UNAVAILABLE;

2697

1895

}

2698

1896

}

2699

1897

2700

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

2701

if(mc.interfaces == NULL){

2702

struct dirent **direntries = NULL;

2703

/* Look for any good interfaces */

2704

ret = scandir(sys_class_net, &direntries, good_interface,

2705

alphasort);

2706

if(ret >= 1){

2707

/* Add all found interfaces to interfaces list */

2708

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

2709

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

2710

direntries[i]->d_name);

2711

if(ret_errno != 0){

2712

errno = ret_errno;

2713

perror_plus("argz_add");

2714

free(direntries[i]);

2715

continue;

2716

}

2717

if(debug){

2718

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

2719

direntries[i]->d_name);

2720

}

2721

free(direntries[i]);

2722

}

2723

free(direntries);

2724

} else {

2725

if(ret == 0){

2726

free(direntries);

2727

}

2728

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

2729

exitcode = EXIT_FAILURE;

2730

goto end;

2731

}

2732

}

2733

2734

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

2735

{

2736

char *interface = NULL;

2737

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

2738

interface))){

2739

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

2740

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

2741

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

2742

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

2743

interface);

2744

interface = NULL;

2745

while((interface = argz_next(mc.interfaces,

2746

mc.interfaces_size, interface))){

2747

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

2748

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

2749

interface);

2750

interface = NULL;

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");

2751

1983

}

2752

1984

}

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){

2753

2002

break;

2754

2003

}

2755

bool interface_was_up = interface_is_up(interface);

2756

errno = bring_up_interface(interface, delay);

2757

if(not interface_was_up){

2758

if(errno != 0){

2759

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

2760

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

2761

} else {

2762

errno = argz_add(&interfaces_to_take_down,

2763

&interfaces_to_take_down_size,

2764

interface);

2765

if(errno != 0){

2766

perror_plus("argz_add");

2767

}

2768

}

2769

}

2770

}

2771

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

2772

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

2773

}

2774

}

2775

2776

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

2777

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

2778

if(debug){

2779

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

2780

mc.interfaces);

2781

}

2782

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

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

}

2783

2033

}

2784

2034

2785

2035

if(quit_now){

2786

2036

goto end;

2787

2037

}

2788

2038

2789

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

2039

ret = init_gnutls_global(pubkey, seckey);

2790

2040

if(ret == -1){

2791

2041

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

2792

2042

exitcode = EX_UNAVAILABLE;

2799

2049

goto end;

2800

2050

}

2801

2051

2802

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

2803

tempdir = mkdtemp(run_tempdir);

2804

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

2805

if(debug){

2806

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

2807

run_tempdir, old_tempdir);

2808

}

2809

tempdir = mkdtemp(old_tempdir);

2810

}

2811

if(tempdir == NULL){

2052

if(mkdtemp(tempdir) == NULL){

2812

2053

perror_plus("mkdtemp");

2813

2054

goto end;

2814

2055

}

2056

tempdir_created = true;

2815

2057

2816

2058

if(quit_now){

2817

2059

goto end;

2818

2060

}

2819

2061

2820

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

2062

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

2821

2063

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

2822

2064

exitcode = EX_UNAVAILABLE;

2823

2065

goto end;

2833

2075

/* Connect directly, do not use Zeroconf */

2834

2076

/* (Mainly meant for debugging) */

2835

2077

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

2836

2837

2078

if(address == NULL){

2838

2079

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

2839

2080

exitcode = EX_USAGE;

2844

2085

goto end;

2845

2086

}

2846

2087

2847

in_port_t port;

2088

uint16_t port;

2848

2089

errno = 0;

2849

2090

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

2850

2091

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

2851

or tmpmax != (in_port_t)tmpmax){

2092

or tmpmax != (uint16_t)tmpmax){

2852

2093

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

2853

2094

exitcode = EX_USAGE;

2854

2095

goto end;

2855

2096

}

2856

2097

2857

2098

if(quit_now){

2858

2099

goto end;

2859

2100

}

2860

2101

2861

port = (in_port_t)tmpmax;

2102

port = (uint16_t)tmpmax;

2862

2103

*address = '\0';

2863

2104

/* Colon in address indicates IPv6 */

2864

2105

int af;

2880

2121

}

2881

2122

2882

2123

while(not quit_now){

2883

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

2884

&mc);

2124

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

2885

2125

if(quit_now or ret == 0){

2886

2126

break;

2887

2127

}

2889

2129

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

2890

2130

(int)retry_interval);

2891

2131

}

2892

sleep((unsigned int)retry_interval);

2132

sleep((int)retry_interval);

2893

2133

}

2894

2134

2895

if(not quit_now){

2135

if (not quit_now){

2896

2136

exitcode = EXIT_SUCCESS;

2897

2137

}

2898

2138

2913

2153

config.publish_domain = 0;

2914

2154

2915

2155

/* Allocate a new server */

2916

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2917

&config, NULL, NULL, &ret);

2156

mc.server = avahi_server_new(avahi_simple_poll_get

2157

(mc.simple_poll), &config, NULL,

2158

NULL, &error);

2918

2159

2919

2160

/* Free the Avahi configuration data */

2920

2161

avahi_server_config_free(&config);

2923

2164

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

2924

2165

if(mc.server == NULL){

2925

2166

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

2926

avahi_strerror(ret));

2167

avahi_strerror(error));

2927

2168

exitcode = EX_UNAVAILABLE;

2928

2169

goto end;

2929

2170

}

2935

2176

/* Create the Avahi service browser */

2936

2177

sb = avahi_s_service_browser_new(mc.server, if_index,

2937

2178

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2938

NULL, 0, browse_callback,

2939

(void *)&mc);

2179

NULL, 0, browse_callback, NULL);

2940

2180

if(sb == NULL){

2941

2181

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

2942

2182

avahi_strerror(avahi_server_errno(mc.server)));

2953

2193

if(debug){

2954

2194

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

2955

2195

}

2956

2957

ret = avahi_loop_with_timeout(simple_poll,

2958

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

2196

2197

ret = avahi_loop_with_timeout(mc.simple_poll,

2198

(int)(retry_interval * 1000));

2959

2199

if(debug){

2960

2200

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

2961

2201

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

2964

2204

end:

2965

2205

2966

2206

if(debug){

2967

if(signal_received){

2968

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

2969

argv[0], signal_received,

2970

strsignal(signal_received));

2971

} else {

2972

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

2973

}

2207

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

2974

2208

}

2975

2209

2976

2210

/* Cleanup things */

2977

free(mc.interfaces);

2978

2979

2211

if(sb != NULL)

2980

2212

avahi_s_service_browser_free(sb);

2981

2213

2982

2214

if(mc.server != NULL)

2983

2215

avahi_server_free(mc.server);

2984

2216

2985

if(simple_poll != NULL)

2986

avahi_simple_poll_free(simple_poll);

2217

if(mc.simple_poll != NULL)

2218

avahi_simple_poll_free(mc.simple_poll);

2987

2219

2988

2220

if(gnutls_initialized){

2989

2221

gnutls_certificate_free_credentials(mc.cred);

2222

gnutls_global_deinit();

2990

2223

gnutls_dh_params_deinit(mc.dh_params);

2991

2224

}

2992

2225

3000

2233

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

3001

2234

while(mc.current_server != NULL){

3002

2235

server *next = mc.current_server->next;

3003

#ifdef __GNUC__

3004

#pragma GCC diagnostic push

3005

#pragma GCC diagnostic ignored "-Wcast-qual"

3006

#endif

3007

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

3008

#ifdef __GNUC__

3009

#pragma GCC diagnostic pop

3010

#endif

3011

2236

free(mc.current_server);

3012

2237

mc.current_server = next;

3013

2238

}

3014

2239

}

3015

2240

3016

/* Re-raise privileges */

2241

/* Run network hooks */

2242

run_network_hooks("stop", interface, delay);

2243

2244

/* Re-raise priviliges */

3017

2245

{

3018

ret = raise_privileges();

3019

if(ret != 0){

3020

errno = ret;

3021

perror_plus("Failed to raise privileges");

3022

} else {

3023

3024

/* Run network hooks */

3025

run_network_hooks("stop", interfaces_hooks != NULL ?

3026

interfaces_hooks : "", delay);

3027

3028

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

3029

{

3030

char *interface = NULL;

3031

while((interface = argz_next(interfaces_to_take_down,

3032

interfaces_to_take_down_size,

3033

interface))){

3034

ret = take_down_interface(interface);

3035

if(ret != 0){

3036

errno = ret;

3037

perror_plus("Failed to take down interface");

3038

}

3039

}

3040

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

3041

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

3042

" down\n");

3043

}

3044

}

2246

errno = 0;

2247

ret = seteuid(0);

2248

if(ret == -1){

2249

perror_plus("seteuid");

3045

2250

}

3046

2251

3047

ret = lower_privileges_permanently();

3048

if(ret != 0){

3049

errno = ret;

3050

perror_plus("Failed to lower privileges permanently");

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

}

3051

2268

}

3052

2269

}

3053

3054

free(interfaces_to_take_down);

3055

free(interfaces_hooks);

3056

3057

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

3058

uintmax_t level){

2270

/* Lower privileges permanently */

2271

errno = 0;

2272

ret = setuid(uid);

2273

if(ret == -1){

2274

perror_plus("setuid");

2275

}

2276

2277

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

2278

if(tempdir_created){

3059

2279

struct dirent **direntries = NULL;

3060

int dret;

3061

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

3062

O_RDONLY

3063

| O_NOFOLLOW

3064

| O_DIRECTORY

3065

| O_PATH));

3066

if(dir_fd == -1){

3067

perror_plus("open");

3068

return;

3069

}

3070

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

3071

notdotentries, alphasort);

3072

if(numentries >= 0){

2280

struct dirent *direntry = NULL;

2281

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

2282

alphasort);

2283

if (numentries > 0){

3073

2284

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

3074

if(debug){

3075

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

3076

dirname, direntries[i]->d_name);

3077

}

3078

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

3079

if(dret == -1){

3080

if(errno == EISDIR){

3081

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

3082

AT_REMOVEDIR);

3083

}

3084

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

3085

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

3086

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

3087

/* Recurse only in this special case */

3088

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

3089

dret = 0;

3090

}

3091

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

3092

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

3093

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

3094

}

3095

}

3096

free(direntries[i]);

3097

}

3098

3099

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

3100

free(direntries);

3101

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3102

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

3103

perror_plus("rmdir");

3104

}

3105

} else {

3106

perror_plus("scandirat");

3107

}

3108

close(dir_fd);

3109

}

3110

3111

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

3112

if(tempdir != NULL){

3113

clean_dir_at(-1, tempdir, 0);

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

}

3114

2311

}

3115

2312

3116

2313

if(quit_now){