/mandos/trunk : revision 738.1.6

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

26

* along with this program. If not, see

27

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

28

*

29

* Contact the authors at <mandos@fukt.bsnet.se>.

29

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

30

*/

31

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

44

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

43

stdout, ferror() */

44

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

45

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

46

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

47

strtof(), abort() */

53

sockaddr_in6, PF_INET6,

54

SOCK_STREAM, uid_t, gid_t, open(),

55

opendir(), DIR */

56

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

56

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

57

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

58

inet_pton(), connect() */

59

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

63

64

strtoimax() */

64

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

65

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

65

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

66

program_invocation_short_name */

66

67

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

67

68

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

68

69

SIOCSIFFLAGS, if_indextoname(),

72

73

*/

73

74

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

74

75

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

75

setgid(), pause() */

76

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

76

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

77

unlinkat() */

78

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

77

79

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

78

80

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

79

81

argp_state, struct argp,

84

86

raise() */

85

87

#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

86

88

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

89

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

90

WEXITSTATUS(), WTERMSIG() */

91

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

92

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

93

argz_delete(), argz_append(),

94

argz_stringify(), argz_add(),

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

87

98

88

99

#ifdef __linux__

89

100

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

107

118

init_gnutls_session(),

108

119

GNUTLS_* */

109

120

#include <gnutls/openpgp.h>

110

/* gnutls_certificate_set_openpgp_key_file(),

111

GNUTLS_OPENPGP_FMT_BASE64 */

121

/* gnutls_certificate_set_openpgp_key_file(),

122

GNUTLS_OPENPGP_FMT_BASE64 */

112

123

113

124

/* GPGME */

114

125

#include <gpgme.h> /* All GPGME types, constants and

122

133

#define PATHDIR "/conf/conf.d/mandos"

123

134

#define SECKEY "seckey.txt"

124

135

#define PUBKEY "pubkey.txt"

136

#define HOOKDIR "/lib/mandos/network-hooks.d"

125

137

126

138

bool debug = false;

127

139

static const char mandos_protocol_version[] = "1";

128

140

const char *argp_program_version = "mandos-client " VERSION;

129

const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

141

const char *argp_program_bug_address = "<mandos@recompile.se>";

130

142

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

131

143

char *connect_to = NULL;

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

uid_t uid = 65534;

147

gid_t gid = 65534;

148

149

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

150

typedef struct server{

151

const char *ip;

152

in_port_t port;

153

AvahiIfIndex if_index;

154

int af;

155

struct timespec last_seen;

156

struct server *next;

157

struct server *prev;

158

} server;

132

159

133

160

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

134

161

typedef struct {

135

AvahiSimplePoll *simple_poll;

136

162

AvahiServer *server;

137

163

gnutls_certificate_credentials_t cred;

138

164

unsigned int dh_bits;

139

165

gnutls_dh_params_t dh_params;

140

166

const char *priority;

141

167

gpgme_ctx_t ctx;

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

142

171

} mandos_context;

143

172

144

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

145

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

146

.dh_bits = 1024, .priority = "SECURE256"

147

":!CTYPE-X.509:+CTYPE-OPENPGP" };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

148

175

149

176

sig_atomic_t quit_now = 0;

150

177

int signal_received = 0;

151

178

179

/* Function to use when printing errors */

180

void perror_plus(const char *print_text){

181

int e = errno;

182

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

183

program_invocation_short_name);

184

errno = e;

185

perror(print_text);

186

}

187

188

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

189

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

190

va_list ap;

191

va_start (ap, format);

192

193

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

194

program_invocation_short_name));

195

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

196

}

197

152

198

/*

153

199

* Make additional room in "buffer" for at least BUFFER_SIZE more

154

200

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

155

201

* "buffer_length" is how much is already used.

156

202

*/

203

__attribute__((nonnull, warn_unused_result))

157

204

size_t incbuffer(char **buffer, size_t buffer_length,

158

size_t buffer_capacity){

205

size_t buffer_capacity){

159

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

160

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

161

if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

162

213

return 0;

163

214

}

215

*buffer = new_buf;

164

216

buffer_capacity += BUFFER_SIZE;

165

217

}

166

218

return buffer_capacity;

167

219

}

168

220

221

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

222

__attribute__((nonnull, warn_unused_result))

223

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

224

int af, server **current_server){

225

int ret;

226

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

227

if(new_server == NULL){

228

perror_plus("malloc");

229

return false;

230

}

231

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

232

.port = port,

233

.if_index = if_index,

234

.af = af };

235

if(new_server->ip == NULL){

236

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

return false;

253

}

254

/* Special case of first server */

255

if(*current_server == NULL){

256

new_server->next = new_server;

257

new_server->prev = new_server;

258

*current_server = new_server;

259

} else {

260

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

261

new_server->next = *current_server;

262

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

263

new_server->prev->next = new_server;

264

(*current_server)->prev = new_server;

265

}

266

return true;

267

}

268

169

269

/*

170

270

* Initialize GPGME.

171

271

*/

172

static bool init_gpgme(const char *seckey,

173

const char *pubkey, const char *tempdir){

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

174

277

gpgme_error_t rc;

175

278

gpgme_engine_info_t engine_info;

176

279

177

178

280

/*

179

281

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

180

282

*/

181

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

182

284

int ret;

183

285

int fd;

184

286

gpgme_data_t pgp_data;

185

287

186

288

fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

187

289

if(fd == -1){

188

perror("open");

290

perror_plus("open");

189

291

return false;

190

292

}

191

293

192

294

rc = gpgme_data_new_from_fd(&pgp_data, fd);

193

295

if(rc != GPG_ERR_NO_ERROR){

194

fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",

195

gpgme_strsource(rc), gpgme_strerror(rc));

296

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

297

gpgme_strsource(rc), gpgme_strerror(rc));

196

298

return false;

197

299

}

198

300

199

rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

200

302

if(rc != GPG_ERR_NO_ERROR){

201

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

202

gpgme_strsource(rc), gpgme_strerror(rc));

303

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

304

gpgme_strsource(rc), gpgme_strerror(rc));

203

305

return false;

204

306

}

205

307

206

308

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

207

309

if(ret == -1){

208

perror("close");

310

perror_plus("close");

209

311

}

210

312

gpgme_data_release(pgp_data);

211

313

return true;

212

314

}

213

315

214

316

if(debug){

215

fprintf(stderr, "Initializing GPGME\n");

317

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

216

318

}

217

319

218

320

/* Init GPGME */

219

321

gpgme_check_version(NULL);

220

322

rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);

221

323

if(rc != GPG_ERR_NO_ERROR){

222

fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",

223

gpgme_strsource(rc), gpgme_strerror(rc));

324

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

325

gpgme_strsource(rc), gpgme_strerror(rc));

224

326

return false;

225

327

}

226

328

227

/* Set GPGME home directory for the OpenPGP engine only */

329

/* Set GPGME home directory for the OpenPGP engine only */

228

330

rc = gpgme_get_engine_info(&engine_info);

229

331

if(rc != GPG_ERR_NO_ERROR){

230

fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

231

gpgme_strsource(rc), gpgme_strerror(rc));

332

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

333

gpgme_strsource(rc), gpgme_strerror(rc));

232

334

return false;

233

335

}

234

336

while(engine_info != NULL){

240

342

engine_info = engine_info->next;

241

343

}

242

344

if(engine_info == NULL){

243

fprintf(stderr, "Could not set GPGME home dir to %s\n", tempdir);

345

fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",

346

tempdir);

244

347

return false;

245

348

}

246

349

247

350

/* Create new GPGME "context" */

248

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

351

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

249

352

if(rc != GPG_ERR_NO_ERROR){

250

fprintf(stderr, "bad gpgme_new: %s: %s\n",

251

gpgme_strsource(rc), gpgme_strerror(rc));

353

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

354

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

355

gpgme_strerror(rc));

252

356

return false;

253

357

}

254

358

263

367

* Decrypt OpenPGP data.

264

368

* Returns -1 on error

265

369

*/

370

__attribute__((nonnull, warn_unused_result))

266

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

267

372

size_t crypto_size,

268

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

269

375

gpgme_data_t dh_crypto, dh_plain;

270

376

gpgme_error_t rc;

271

377

ssize_t ret;

273

379

ssize_t plaintext_length = 0;

274

380

275

381

if(debug){

276

fprintf(stderr, "Trying to decrypt OpenPGP data\n");

382

fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");

277

383

}

278

384

279

385

/* Create new GPGME data buffer from memory cryptotext */

280

386

rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,

281

387

0);

282

388

if(rc != GPG_ERR_NO_ERROR){

283

fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",

284

gpgme_strsource(rc), gpgme_strerror(rc));

389

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

390

gpgme_strsource(rc), gpgme_strerror(rc));

285

391

return -1;

286

392

}

287

393

288

394

/* Create new empty GPGME data buffer for the plaintext */

289

395

rc = gpgme_data_new(&dh_plain);

290

396

if(rc != GPG_ERR_NO_ERROR){

291

fprintf(stderr, "bad gpgme_data_new: %s: %s\n",

292

gpgme_strsource(rc), gpgme_strerror(rc));

397

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

398

"bad gpgme_data_new: %s: %s\n",

399

gpgme_strsource(rc), gpgme_strerror(rc));

293

400

gpgme_data_release(dh_crypto);

294

401

return -1;

295

402

}

296

403

297

404

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

298

405

data buffer */

299

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

406

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

300

407

if(rc != GPG_ERR_NO_ERROR){

301

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

302

gpgme_strsource(rc), gpgme_strerror(rc));

408

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

409

gpgme_strsource(rc), gpgme_strerror(rc));

303

410

plaintext_length = -1;

304

411

if(debug){

305

412

gpgme_decrypt_result_t result;

306

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

307

414

if(result == NULL){

308

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

415

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

309

416

} else {

310

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

311

result->unsupported_algorithm);

312

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

313

result->wrong_key_usage);

417

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

418

result->unsupported_algorithm);

419

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

420

result->wrong_key_usage);

314

421

if(result->file_name != NULL){

315

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

422

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

316

423

}

317

424

gpgme_recipient_t recipient;

318

425

recipient = result->recipients;

319

426

while(recipient != NULL){

320

fprintf(stderr, "Public key algorithm: %s\n",

321

gpgme_pubkey_algo_name(recipient->pubkey_algo));

322

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

323

fprintf(stderr, "Secret key available: %s\n",

324

recipient->status == GPG_ERR_NO_SECKEY

325

? "No" : "Yes");

427

fprintf_plus(stderr, "Public key algorithm: %s\n",

428

gpgme_pubkey_algo_name

429

(recipient->pubkey_algo));

430

fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);

431

fprintf_plus(stderr, "Secret key available: %s\n",

432

recipient->status == GPG_ERR_NO_SECKEY

433

? "No" : "Yes");

326

434

recipient = recipient->next;

327

435

}

328

436

}

331

439

}

332

440

333

441

if(debug){

334

fprintf(stderr, "Decryption of OpenPGP data succeeded\n");

442

fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");

335

443

}

336

444

337

445

/* Seek back to the beginning of the GPGME plaintext data buffer */

338

446

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

339

perror("gpgme_data_seek");

447

perror_plus("gpgme_data_seek");

340

448

plaintext_length = -1;

341

449

goto decrypt_end;

342

450

}

344

452

*plaintext = NULL;

345

453

while(true){

346

454

plaintext_capacity = incbuffer(plaintext,

347

(size_t)plaintext_length,

348

plaintext_capacity);

455

(size_t)plaintext_length,

456

plaintext_capacity);

349

457

if(plaintext_capacity == 0){

350

perror("incbuffer");

351

plaintext_length = -1;

352

goto decrypt_end;

458

perror_plus("incbuffer");

459

plaintext_length = -1;

460

goto decrypt_end;

353

461

}

354

462

355

463

ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,

360

468

break;

361

469

}

362

470

if(ret < 0){

363

perror("gpgme_data_read");

471

perror_plus("gpgme_data_read");

364

472

plaintext_length = -1;

365

473

goto decrypt_end;

366

474

}

368

476

}

369

477

370

478

if(debug){

371

fprintf(stderr, "Decrypted password is: ");

479

fprintf_plus(stderr, "Decrypted password is: ");

372

480

for(ssize_t i = 0; i < plaintext_length; i++){

373

481

fprintf(stderr, "%02hhX ", (*plaintext)[i]);

374

482

}

385

493

return plaintext_length;

386

494

}

387

495

388

static const char * safer_gnutls_strerror(int value){

389

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

390

-Wunreachable-code */

496

__attribute__((warn_unused_result))

497

static const char *safer_gnutls_strerror(int value){

498

const char *ret = gnutls_strerror(value);

391

499

if(ret == NULL)

392

500

ret = "(unknown)";

393

501

return ret;

394

502

}

395

503

396

504

/* GnuTLS log function callback */

505

__attribute__((nonnull))

397

506

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

398

507

const char* string){

399

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

508

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

400

509

}

401

510

511

__attribute__((nonnull, warn_unused_result))

402

512

static int init_gnutls_global(const char *pubkeyfilename,

403

const char *seckeyfilename){

513

const char *seckeyfilename,

514

mandos_context *mc){

404

515

int ret;

405

516

406

517

if(debug){

407

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

518

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

408

519

}

409

520

410

521

ret = gnutls_global_init();

411

522

if(ret != GNUTLS_E_SUCCESS){

412

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

413

safer_gnutls_strerror(ret));

523

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

524

safer_gnutls_strerror(ret));

414

525

return -1;

415

526

}

416

527

423

534

}

424

535

425

536

/* OpenPGP credentials */

426

gnutls_certificate_allocate_credentials(&mc.cred);

537

ret = gnutls_certificate_allocate_credentials(&mc->cred);

427

538

if(ret != GNUTLS_E_SUCCESS){

428

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

429

from

430

-Wunreachable-code

431

*/

432

safer_gnutls_strerror(ret));

539

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

540

safer_gnutls_strerror(ret));

433

541

gnutls_global_deinit();

434

542

return -1;

435

543

}

436

544

437

545

if(debug){

438

fprintf(stderr, "Attempting to use OpenPGP public key %s and"

439

" secret key %s as GnuTLS credentials\n", pubkeyfilename,

440

seckeyfilename);

546

fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"

547

" secret key %s as GnuTLS credentials\n",

548

pubkeyfilename,

549

seckeyfilename);

441

550

}

442

551

443

552

ret = gnutls_certificate_set_openpgp_key_file

444

(mc.cred, pubkeyfilename, seckeyfilename,

553

(mc->cred, pubkeyfilename, seckeyfilename,

445

554

GNUTLS_OPENPGP_FMT_BASE64);

446

555

if(ret != GNUTLS_E_SUCCESS){

447

fprintf(stderr,

448

"Error[%d] while reading the OpenPGP key pair ('%s',"

449

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

450

fprintf(stderr, "The GnuTLS error is: %s\n",

451

safer_gnutls_strerror(ret));

556

fprintf_plus(stderr,

557

"Error[%d] while reading the OpenPGP key pair ('%s',"

558

" '%s')\n", ret, pubkeyfilename, seckeyfilename);

559

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

560

safer_gnutls_strerror(ret));

452

561

goto globalfail;

453

562

}

454

563

455

564

/* GnuTLS server initialization */

456

ret = gnutls_dh_params_init(&mc.dh_params);

565

ret = gnutls_dh_params_init(&mc->dh_params);

457

566

if(ret != GNUTLS_E_SUCCESS){

458

fprintf(stderr, "Error in GnuTLS DH parameter initialization:"

459

" %s\n", safer_gnutls_strerror(ret));

567

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

568

" initialization: %s\n",

569

safer_gnutls_strerror(ret));

460

570

goto globalfail;

461

571

}

462

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

572

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

463

573

if(ret != GNUTLS_E_SUCCESS){

464

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

465

safer_gnutls_strerror(ret));

574

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

575

safer_gnutls_strerror(ret));

466

576

goto globalfail;

467

577

}

468

578

469

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

579

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

470

580

471

581

return 0;

472

582

473

583

globalfail:

474

584

475

gnutls_certificate_free_credentials(mc.cred);

585

gnutls_certificate_free_credentials(mc->cred);

476

586

gnutls_global_deinit();

477

gnutls_dh_params_deinit(mc.dh_params);

587

gnutls_dh_params_deinit(mc->dh_params);

478

588

return -1;

479

589

}

480

590

481

static int init_gnutls_session(gnutls_session_t *session){

591

__attribute__((nonnull, warn_unused_result))

592

static int init_gnutls_session(gnutls_session_t *session,

593

mandos_context *mc){

482

594

int ret;

483

595

/* GnuTLS session creation */

484

596

do {

488

600

}

489

601

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

490

602

if(ret != GNUTLS_E_SUCCESS){

491

fprintf(stderr, "Error in GnuTLS session initialization: %s\n",

492

safer_gnutls_strerror(ret));

603

fprintf_plus(stderr,

604

"Error in GnuTLS session initialization: %s\n",

605

safer_gnutls_strerror(ret));

493

606

}

494

607

495

608

{

496

609

const char *err;

497

610

do {

498

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

611

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

499

612

if(quit_now){

500

613

gnutls_deinit(*session);

501

614

return -1;

502

615

}

503

616

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

504

617

if(ret != GNUTLS_E_SUCCESS){

505

fprintf(stderr, "Syntax error at: %s\n", err);

506

fprintf(stderr, "GnuTLS error: %s\n",

507

safer_gnutls_strerror(ret));

618

fprintf_plus(stderr, "Syntax error at: %s\n", err);

619

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

620

safer_gnutls_strerror(ret));

508

621

gnutls_deinit(*session);

509

622

return -1;

510

623

}

512

625

513

626

do {

514

627

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

515

mc.cred);

628

mc->cred);

516

629

if(quit_now){

517

630

gnutls_deinit(*session);

518

631

return -1;

519

632

}

520

633

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

521

634

if(ret != GNUTLS_E_SUCCESS){

522

fprintf(stderr, "Error setting GnuTLS credentials: %s\n",

523

safer_gnutls_strerror(ret));

635

fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",

636

safer_gnutls_strerror(ret));

524

637

gnutls_deinit(*session);

525

638

return -1;

526

639

}

528

641

/* ignore client certificate if any. */

529

642

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

530

643

531

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

532

645

533

646

return 0;

534

647

}

537

650

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

538

651

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

539

652

653

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

654

__attribute__((warn_unused_result))

655

error_t raise_privileges(void){

656

error_t old_errno = errno;

657

error_t ret_errno = 0;

658

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

659

ret_errno = errno;

660

}

661

errno = old_errno;

662

return ret_errno;

663

}

664

665

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

666

__attribute__((warn_unused_result))

667

error_t raise_privileges_permanently(void){

668

error_t old_errno = errno;

669

error_t ret_errno = raise_privileges();

670

if(ret_errno != 0){

671

errno = old_errno;

672

return ret_errno;

673

}

674

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

675

ret_errno = errno;

676

}

677

errno = old_errno;

678

return ret_errno;

679

}

680

681

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

682

__attribute__((warn_unused_result))

683

error_t lower_privileges(void){

684

error_t old_errno = errno;

685

error_t ret_errno = 0;

686

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

687

ret_errno = errno;

688

}

689

errno = old_errno;

690

return ret_errno;

691

}

692

693

/* Lower privileges permanently */

694

__attribute__((warn_unused_result))

695

error_t lower_privileges_permanently(void){

696

error_t old_errno = errno;

697

error_t ret_errno = 0;

698

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

699

ret_errno = errno;

700

}

701

errno = old_errno;

702

return ret_errno;

703

}

704

705

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

706

__attribute__((nonnull, warn_unused_result))

707

static bool add_delete_local_route(const bool add,

708

const char *address,

709

AvahiIfIndex if_index){

710

int ret;

711

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

712

char add_arg[] = "add";

713

char delete_arg[] = "delete";

714

char debug_flag[] = "--debug";

715

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

716

if(pluginhelperdir == NULL){

717

if(debug){

718

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

719

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

720

}

721

return false;

722

}

723

724

char interface[IF_NAMESIZE];

725

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

726

perror_plus("if_indextoname");

727

return false;

728

}

729

730

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

731

if(devnull == -1){

732

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

733

return false;

734

}

735

pid_t pid = fork();

736

if(pid == 0){

737

/* Child */

738

/* Raise privileges */

739

errno = raise_privileges_permanently();

740

if(errno != 0){

741

perror_plus("Failed to raise privileges");

742

/* _exit(EX_NOPERM); */

743

} else {

744

/* Set group */

745

errno = 0;

746

ret = setgid(0);

747

if(ret == -1){

748

perror_plus("setgid");

749

_exit(EX_NOPERM);

750

}

751

/* Reset supplementary groups */

752

errno = 0;

753

ret = setgroups(0, NULL);

754

if(ret == -1){

755

perror_plus("setgroups");

756

_exit(EX_NOPERM);

757

}

758

}

759

ret = dup2(devnull, STDIN_FILENO);

760

if(ret == -1){

761

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

762

_exit(EX_OSERR);

763

}

764

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

765

if(ret == -1){

766

perror_plus("close");

767

_exit(EX_OSERR);

768

}

769

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

770

if(ret == -1){

771

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

772

_exit(EX_OSERR);

773

}

774

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

775

O_RDONLY

776

| O_DIRECTORY

777

| O_PATH

778

| O_CLOEXEC));

779

if(helperdir_fd == -1){

780

perror_plus("open");

781

_exit(EX_UNAVAILABLE);

782

}

783

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

784

helper, O_RDONLY));

785

if(helper_fd == -1){

786

perror_plus("openat");

787

_exit(EX_UNAVAILABLE);

788

}

789

TEMP_FAILURE_RETRY(close(helperdir_fd));

790

#ifdef __GNUC__

791

#pragma GCC diagnostic push

792

#pragma GCC diagnostic ignored "-Wcast-qual"

793

#endif

794

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

795

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

796

interface, debug ? debug_flag : NULL, NULL },

797

environ) == -1){

798

#ifdef __GNUC__

799

#pragma GCC diagnostic pop

800

#endif

801

perror_plus("fexecve");

802

_exit(EXIT_FAILURE);

803

}

804

}

805

if(pid == -1){

806

perror_plus("fork");

807

return false;

808

}

809

int status;

810

pid_t pret = -1;

811

errno = 0;

812

do {

813

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

814

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

815

int errno_raising = 0;

816

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

817

errno_raising = errno;

818

perror_plus("Failed to raise privileges in order to"

819

" kill helper program");

820

}

821

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

822

perror_plus("kill");

823

}

824

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

825

perror_plus("Failed to lower privileges after killing"

826

" helper program");

827

}

828

return false;

829

}

830

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

831

if(pret == -1){

832

perror_plus("waitpid");

833

return false;

834

}

835

if(WIFEXITED(status)){

836

if(WEXITSTATUS(status) != 0){

837

fprintf_plus(stderr, "Error: iprouteadddel exited"

838

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

839

return false;

840

}

841

return true;

842

}

843

if(WIFSIGNALED(status)){

844

fprintf_plus(stderr, "Error: iprouteadddel died by"

845

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

846

return false;

847

}

848

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

849

return false;

850

}

851

852

__attribute__((nonnull, warn_unused_result))

853

static bool add_local_route(const char *address,

854

AvahiIfIndex if_index){

855

if(debug){

856

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

857

}

858

return add_delete_local_route(true, address, if_index);

859

}

860

861

__attribute__((nonnull, warn_unused_result))

862

static bool delete_local_route(const char *address,

863

AvahiIfIndex if_index){

864

if(debug){

865

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

866

}

867

return add_delete_local_route(false, address, if_index);

868

}

869

540

870

/* Called when a Mandos server is found */

541

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

871

__attribute__((nonnull, warn_unused_result))

872

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

542

873

AvahiIfIndex if_index,

543

int af){

874

int af, mandos_context *mc){

544

875

int ret, tcp_sd = -1;

545

876

ssize_t sret;

546

union {

547

struct sockaddr_in in;

548

struct sockaddr_in6 in6;

549

} to;

877

struct sockaddr_storage to;

550

878

char *buffer = NULL;

551

879

char *decrypted_buffer = NULL;

552

880

size_t buffer_length = 0;

555

883

int retval = -1;

556

884

gnutls_session_t session;

557

885

int pf; /* Protocol family */

886

bool route_added = false;

558

887

559

888

errno = 0;

560

889

571

900

pf = PF_INET;

572

901

break;

573

902

default:

574

fprintf(stderr, "Bad address family: %d\n", af);

903

fprintf_plus(stderr, "Bad address family: %d\n", af);

575

904

errno = EINVAL;

576

905

return -1;

577

906

}

578

907

579

ret = init_gnutls_session(&session);

908

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

909

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

910

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

911

bool match = false;

912

{

913

char *interface = NULL;

914

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

915

interface))){

916

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

917

match = true;

918

break;

919

}

920

}

921

}

922

if(not match){

923

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

924

connect to the server */

925

if(debug){

926

char interface[IF_NAMESIZE];

927

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

928

perror_plus("if_indextoname");

929

} else {

930

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

931

" \"%s\"\n",

932

if_indextoname((unsigned int)if_index,

933

interface));

934

}

935

}

936

return -1;

937

}

938

}

939

940

ret = init_gnutls_session(&session, mc);

580

941

if(ret != 0){

581

942

return -1;

582

943

}

583

944

584

945

if(debug){

585

fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16

586

"\n", ip, port);

946

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

947

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

587

948

}

588

949

589

tcp_sd = socket(pf, SOCK_STREAM, 0);

950

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

590

951

if(tcp_sd < 0){

591

952

int e = errno;

592

perror("socket");

953

perror_plus("socket");

593

954

errno = e;

594

955

goto mandos_end;

595

956

}

601

962

602

963

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

603

964

if(af == AF_INET6){

604

to.in6.sin6_family = (sa_family_t)af;

605

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

965

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

966

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

606

967

} else { /* IPv4 */

607

to.in.sin_family = (sa_family_t)af;

608

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

968

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

969

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

609

970

}

610

971

if(ret < 0 ){

611

972

int e = errno;

612

perror("inet_pton");

973

perror_plus("inet_pton");

613

974

errno = e;

614

975

goto mandos_end;

615

976

}

616

977

if(ret == 0){

617

978

int e = errno;

618

fprintf(stderr, "Bad address: %s\n", ip);

979

fprintf_plus(stderr, "Bad address: %s\n", ip);

619

980

errno = e;

620

981

goto mandos_end;

621

982

}

622

983

if(af == AF_INET6){

623

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

624

-Wconversion and

625

-Wunreachable-code */

626

627

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

628

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

629

-Wunreachable-code*/

984

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

985

if(IN6_IS_ADDR_LINKLOCAL

986

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

630

987

if(if_index == AVAHI_IF_UNSPEC){

631

fprintf(stderr, "An IPv6 link-local address is incomplete"

632

" without a network interface\n");

988

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

989

" incomplete without a network interface\n");

633

990

errno = EINVAL;

634

991

goto mandos_end;

635

992

}

636

993

/* Set the network interface number as scope */

637

to.in6.sin6_scope_id = (uint32_t)if_index;

994

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

638

995

}

639

996

} else {

640

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

641

-Wconversion and

642

-Wunreachable-code */

997

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

643

998

}

644

999

645

1000

if(quit_now){

651

1006

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

652

1007

char interface[IF_NAMESIZE];

653

1008

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

654

perror("if_indextoname");

1009

perror_plus("if_indextoname");

655

1010

} else {

656

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

657

ip, interface, port);

1011

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

1012

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

658

1013

}

659

1014

} else {

660

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

661

port);

1015

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

1016

ip, (uintmax_t)port);

662

1017

}

663

1018

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

664

1019

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

665

const char *pcret;

666

if(af == AF_INET6){

667

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

668

sizeof(addrstr));

669

} else {

670

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

671

sizeof(addrstr));

672

}

673

if(pcret == NULL){

674

perror("inet_ntop");

675

} else {

676

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

677

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

678

}

679

}

680

}

681

682

if(quit_now){

683

errno = EINTR;

684

goto mandos_end;

685

}

686

687

if(af == AF_INET6){

688

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

689

} else {

690

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

691

}

692

if(ret < 0){

693

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

694

int e = errno;

695

perror("connect");

696

errno = e;

697

}

698

goto mandos_end;

699

}

700

701

if(quit_now){

702

errno = EINTR;

703

goto mandos_end;

1020

if(af == AF_INET6){

1021

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

1022

sizeof(struct sockaddr_in6),

1023

addrstr, sizeof(addrstr), NULL, 0,

1024

NI_NUMERICHOST);

1025

} else {

1026

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

1027

sizeof(struct sockaddr_in),

1028

addrstr, sizeof(addrstr), NULL, 0,

1029

NI_NUMERICHOST);

1030

}

1031

if(ret == EAI_SYSTEM){

1032

perror_plus("getnameinfo");

1033

} else if(ret != 0) {

1034

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

1035

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

1036

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

1037

}

1038

}

1039

1040

if(quit_now){

1041

errno = EINTR;

1042

goto mandos_end;

1043

}

1044

1045

while(true){

1046

if(af == AF_INET6){

1047

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

1048

sizeof(struct sockaddr_in6));

1049

} else {

1050

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

1051

sizeof(struct sockaddr_in));

1052

}

1053

if(ret < 0){

1054

if(errno == ENETUNREACH

1055

and if_index != AVAHI_IF_UNSPEC

1056

and connect_to == NULL

1057

and not route_added and

1058

((af == AF_INET6 and not

1059

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1060

&to)->sin6_addr)))

1061

or (af == AF_INET and

1062

/* Not a a IPv4LL address */

1063

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

1064

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

1065

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

1066

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

1067

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

1068

connect to a Mandos server announced by Avahi on a server

1069

host with a global address. Work around this by retrying

1070

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

1071

1072

Avahi bug reference:

1073

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

1074

https://bugs.debian.org/587961

1075

*/

1076

if(debug){

1077

fprintf_plus(stderr, "Mandos server unreachable, trying"

1078

" direct route\n");

1079

}

1080

int e = errno;

1081

route_added = add_local_route(ip, if_index);

1082

if(route_added){

1083

continue;

1084

}

1085

errno = e;

1086

}

1087

if(errno != ECONNREFUSED or debug){

1088

int e = errno;

1089

perror_plus("connect");

1090

errno = e;

1091

}

1092

goto mandos_end;

1093

}

1094

1095

if(quit_now){

1096

errno = EINTR;

1097

goto mandos_end;

1098

}

1099

break;

704

1100

}

705

1101

706

1102

const char *out = mandos_protocol_version;

708

1104

while(true){

709

1105

size_t out_size = strlen(out);

710

1106

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

711

out_size - written));

1107

out_size - written));

712

1108

if(ret == -1){

713

1109

int e = errno;

714

perror("write");

1110

perror_plus("write");

715

1111

errno = e;

716

1112

goto mandos_end;

717

1113

}

734

1130

}

735

1131

736

1132

if(debug){

737

fprintf(stderr, "Establishing TLS session with %s\n", ip);

1133

fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);

738

1134

}

739

1135

740

1136

if(quit_now){

742

1138

goto mandos_end;

743

1139

}

744

1140

745

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1141

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

1142

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

1143

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

1144

gnutls_transport_set_ptr(session,

1145

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

746

1146

747

1147

if(quit_now){

748

1148

errno = EINTR;

759

1159

760

1160

if(ret != GNUTLS_E_SUCCESS){

761

1161

if(debug){

762

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

1162

fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");

763

1163

gnutls_perror(ret);

764

1164

}

765

1165

errno = EPROTO;

769

1169

/* Read OpenPGP packet that contains the wanted password */

770

1170

771

1171

if(debug){

772

fprintf(stderr, "Retrieving OpenPGP encrypted password from %s\n",

773

ip);

1172

fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"

1173

" %s\n", ip);

774

1174

}

775

1175

776

1176

while(true){

781

1181

}

782

1182

783

1183

buffer_capacity = incbuffer(&buffer, buffer_length,

784

buffer_capacity);

1184

buffer_capacity);

785

1185

if(buffer_capacity == 0){

786

1186

int e = errno;

787

perror("incbuffer");

1187

perror_plus("incbuffer");

788

1188

errno = e;

789

1189

goto mandos_end;

790

1190

}

814

1214

}

815

1215

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

816

1216

if(ret < 0){

817

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

1217

fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "

1218

"***\n");

818

1219

gnutls_perror(ret);

819

1220

errno = EPROTO;

820

1221

goto mandos_end;

821

1222

}

822

1223

break;

823

1224

default:

824

fprintf(stderr, "Unknown error while reading data from"

825

" encrypted session with Mandos server\n");

1225

fprintf_plus(stderr, "Unknown error while reading data from"

1226

" encrypted session with Mandos server\n");

826

1227

gnutls_bye(session, GNUTLS_SHUT_RDWR);

827

1228

errno = EIO;

828

1229

goto mandos_end;

833

1234

}

834

1235

835

1236

if(debug){

836

fprintf(stderr, "Closing TLS session\n");

1237

fprintf_plus(stderr, "Closing TLS session\n");

837

1238

}

838

1239

839

1240

if(quit_now){

851

1252

852

1253

if(buffer_length > 0){

853

1254

ssize_t decrypted_buffer_size;

854

decrypted_buffer_size = pgp_packet_decrypt(buffer,

855

buffer_length,

856

&decrypted_buffer);

1255

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1256

&decrypted_buffer, mc);

857

1257

if(decrypted_buffer_size >= 0){

858

1258

859

1259

written = 0;

869

1269

if(ret == 0 and ferror(stdout)){

870

1270

int e = errno;

871

1271

if(debug){

872

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

873

strerror(errno));

1272

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

1273

strerror(errno));

874

1274

}

875

1275

errno = e;

876

1276

goto mandos_end;

885

1285

886

1286

mandos_end:

887

1287

{

1288

if(route_added){

1289

if(not delete_local_route(ip, if_index)){

1290

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

1291

" interface %d", ip, if_index);

1292

}

1293

}

888

1294

int e = errno;

889

1295

free(decrypted_buffer);

890

1296

free(buffer);

895

1301

if(e == 0){

896

1302

e = errno;

897

1303

}

898

perror("close");

1304

perror_plus("close");

899

1305

}

900

1306

gnutls_deinit(session);

1307

errno = e;

901

1308

if(quit_now){

902

e = EINTR;

1309

errno = EINTR;

903

1310

retval = -1;

904

1311

}

905

errno = e;

906

1312

}

907

1313

return retval;

908

1314

}

909

1315

1316

__attribute__((nonnull))

910

1317

static void resolve_callback(AvahiSServiceResolver *r,

911

1318

AvahiIfIndex interface,

912

1319

AvahiProtocol proto,

920

1327

AVAHI_GCC_UNUSED AvahiStringList *txt,

921

1328

AVAHI_GCC_UNUSED AvahiLookupResultFlags

922

1329

flags,

923

AVAHI_GCC_UNUSED void* userdata){

924

assert(r);

1330

void *mc){

1331

if(r == NULL){

1332

return;

1333

}

925

1334

926

1335

/* Called whenever a service has been resolved successfully or

927

1336

timed out */

928

1337

929

1338

if(quit_now){

1339

avahi_s_service_resolver_free(r);

930

1340

return;

931

1341

}

932

1342

933

1343

switch(event){

934

1344

default:

935

1345

case AVAHI_RESOLVER_FAILURE:

936

fprintf(stderr, "(Avahi Resolver) Failed to resolve service '%s'"

937

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

938

avahi_strerror(avahi_server_errno(mc.server)));

1346

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

1347

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

1348

domain,

1349

avahi_strerror(avahi_server_errno

1350

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

939

1351

break;

940

1352

941

1353

case AVAHI_RESOLVER_FOUND:

943

1355

char ip[AVAHI_ADDRESS_STR_MAX];

944

1356

avahi_address_snprint(ip, sizeof(ip), address);

945

1357

if(debug){

946

fprintf(stderr, "Mandos server \"%s\" found on %s (%s, %"

947

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

948

ip, (intmax_t)interface, port);

1358

fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"

1359

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

1360

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

949

1361

}

950

int ret = start_mandos_communication(ip, port, interface,

951

avahi_proto_to_af(proto));

1362

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

1363

interface,

1364

avahi_proto_to_af(proto),

1365

mc);

952

1366

if(ret == 0){

953

avahi_simple_poll_quit(mc.simple_poll);

1367

avahi_simple_poll_quit(simple_poll);

1368

} else {

1369

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

1370

avahi_proto_to_af(proto),

1371

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

1372

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

1373

" list\n", name);

1374

}

954

1375

}

955

1376

}

956

1377

}

966

1387

const char *domain,

967

1388

AVAHI_GCC_UNUSED AvahiLookupResultFlags

968

1389

flags,

969

AVAHI_GCC_UNUSED void* userdata){

970

assert(b);

1390

void *mc){

1391

if(b == NULL){

1392

return;

1393

}

971

1394

972

1395

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

973

1396

is removed from the LAN */

980

1403

default:

981

1404

case AVAHI_BROWSER_FAILURE:

982

1405

983

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

984

avahi_strerror(avahi_server_errno(mc.server)));

985

avahi_simple_poll_quit(mc.simple_poll);

1406

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

1407

avahi_strerror(avahi_server_errno

1408

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

1409

avahi_simple_poll_quit(simple_poll);

986

1410

return;

987

1411

988

1412

case AVAHI_BROWSER_NEW:

991

1415

the callback function is called the Avahi server will free the

992

1416

resolver for us. */

993

1417

994

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

995

name, type, domain, protocol, 0,

996

resolve_callback, NULL) == NULL)

997

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

998

name, avahi_strerror(avahi_server_errno(mc.server)));

1418

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

1419

interface, protocol, name, type,

1420

domain, protocol, 0,

1421

resolve_callback, mc) == NULL)

1422

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

1423

" %s\n", name,

1424

avahi_strerror(avahi_server_errno

1425

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

999

1426

break;

1000

1427

1001

1428

case AVAHI_BROWSER_REMOVE:

1004

1431

case AVAHI_BROWSER_ALL_FOR_NOW:

1005

1432

case AVAHI_BROWSER_CACHE_EXHAUSTED:

1006

1433

if(debug){

1007

fprintf(stderr, "No Mandos server found, still searching...\n");

1434

fprintf_plus(stderr, "No Mandos server found, still"

1435

" searching...\n");

1008

1436

}

1009

1437

break;

1010

1438

}

1011

1439

}

1012

1440

1013

/* stop main loop after sigterm has been called */

1441

/* Signal handler that stops main loop after SIGTERM */

1014

1442

static void handle_sigterm(int sig){

1015

1443

if(quit_now){

1016

1444

return;

1018

1446

quit_now = 1;

1019

1447

signal_received = sig;

1020

1448

int old_errno = errno;

1021

if(mc.simple_poll != NULL){

1022

avahi_simple_poll_quit(mc.simple_poll);

1449

/* set main loop to exit */

1450

if(simple_poll != NULL){

1451

avahi_simple_poll_quit(simple_poll);

1023

1452

}

1024

1453

errno = old_errno;

1025

1454

}

1026

1455

1456

__attribute__((nonnull, warn_unused_result))

1457

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

1458

int ret;

1459

error_t ret_errno;

1460

1461

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

1462

if(s < 0){

1463

ret_errno = errno;

1464

perror_plus("socket");

1465

errno = ret_errno;

1466

return false;

1467

}

1468

strcpy(ifr->ifr_name, ifname);

1469

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1470

if(ret == -1){

1471

if(debug){

1472

ret_errno = errno;

1473

perror_plus("ioctl SIOCGIFFLAGS");

1474

errno = ret_errno;

1475

}

1476

return false;

1477

}

1478

return true;

1479

}

1480

1481

__attribute__((nonnull, warn_unused_result))

1482

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

1483

1484

/* Reject the loopback device */

1485

if(ifr->ifr_flags & IFF_LOOPBACK){

1486

if(debug){

1487

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

1488

ifname);

1489

}

1490

return false;

1491

}

1492

/* Accept point-to-point devices only if connect_to is specified */

1493

if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){

1494

if(debug){

1495

fprintf_plus(stderr, "Accepting point-to-point interface"

1496

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

1497

}

1498

return true;

1499

}

1500

/* Otherwise, reject non-broadcast-capable devices */

1501

if(not (ifr->ifr_flags & IFF_BROADCAST)){

1502

if(debug){

1503

fprintf_plus(stderr, "Rejecting non-broadcast interface"

1504

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

1505

}

1506

return false;

1507

}

1508

/* Reject non-ARP interfaces (including dummy interfaces) */

1509

if(ifr->ifr_flags & IFF_NOARP){

1510

if(debug){

1511

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

1512

ifname);

1513

}

1514

return false;

1515

}

1516

1517

/* Accept this device */

1518

if(debug){

1519

fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);

1520

}

1521

return true;

1522

}

1523

1027

1524

/*

1028

1525

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

1029

1526

* corresponds to an acceptable network device.

1030

1527

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

1031

1528

*/

1529

__attribute__((nonnull, warn_unused_result))

1032

1530

int good_interface(const struct dirent *if_entry){

1033

ssize_t ssret;

1034

char *flagname = NULL;

1035

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1036

if_entry->d_name);

1037

if(ret < 0){

1038

perror("asprintf");

1039

return 0;

1040

}

1041

1531

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

1042

1532

return 0;

1043

1533

}

1044

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1045

if(flags_fd == -1){

1046

perror("open");

1047

return 0;

1048

}

1049

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1050

/* read line from flags_fd */

1051

ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */

1052

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1053

flagstring[(size_t)to_read] = '\0';

1054

if(flagstring == NULL){

1055

perror("malloc");

1056

close(flags_fd);

1057

return 0;

1058

}

1059

while(to_read > 0){

1060

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1061

(size_t)to_read));

1062

if(ssret == -1){

1063

perror("read");

1064

free(flagstring);

1065

close(flags_fd);

1066

return 0;

1067

}

1068

to_read -= ssret;

1069

if(ssret == 0){

1534

1535

struct ifreq ifr;

1536

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

1537

if(debug){

1538

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

1539

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

1540

}

1541

return 0;

1542

}

1543

1544

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

1545

return 0;

1546

}

1547

return 1;

1548

}

1549

1550

/*

1551

* This function determines if a network interface is up.

1552

*/

1553

__attribute__((nonnull, warn_unused_result))

1554

bool interface_is_up(const char *interface){

1555

struct ifreq ifr;

1556

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

1557

if(debug){

1558

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

1559

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

1560

}

1561

return false;

1562

}

1563

1564

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

1565

}

1566

1567

/*

1568

* This function determines if a network interface is running

1569

*/

1570

__attribute__((nonnull, warn_unused_result))

1571

bool interface_is_running(const char *interface){

1572

struct ifreq ifr;

1573

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

1574

if(debug){

1575

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

1576

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

1577

}

1578

return false;

1579

}

1580

1581

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

1582

}

1583

1584

__attribute__((nonnull, pure, warn_unused_result))

1585

int notdotentries(const struct dirent *direntry){

1586

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

1587

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

1588

and (direntry->d_name[1] == '\0'

1589

or (direntry->d_name[1] == '.'

1590

and direntry->d_name[2] == '\0'))){

1591

return 0;

1592

}

1593

return 1;

1594

}

1595

1596

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

1597

__attribute__((nonnull, warn_unused_result))

1598

int runnable_hook(const struct dirent *direntry){

1599

int ret;

1600

size_t sret;

1601

struct stat st;

1602

1603

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

1604

/* Empty name? */

1605

return 0;

1606

}

1607

1608

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

1609

"abcdefghijklmnopqrstuvwxyz"

1610

"0123456789"

1611

"_.-");

1612

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

1613

/* Contains non-allowed characters */

1614

if(debug){

1615

fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",

1616

direntry->d_name);

1617

}

1618

return 0;

1619

}

1620

1621

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

1622

if(ret == -1){

1623

if(debug){

1624

perror_plus("Could not stat hook");

1625

}

1626

return 0;

1627

}

1628

if(not (S_ISREG(st.st_mode))){

1629

/* Not a regular file */

1630

if(debug){

1631

fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",

1632

direntry->d_name);

1633

}

1634

return 0;

1635

}

1636

if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){

1637

/* Not executable */

1638

if(debug){

1639

fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",

1640

direntry->d_name);

1641

}

1642

return 0;

1643

}

1644

if(debug){

1645

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

1646

direntry->d_name);

1647

}

1648

return 1;

1649

}

1650

1651

__attribute__((nonnull, warn_unused_result))

1652

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1653

mandos_context *mc){

1654

int ret;

1655

struct timespec now;

1656

struct timespec waited_time;

1657

intmax_t block_time;

1658

1659

while(true){

1660

if(mc->current_server == NULL){

1661

if(debug){

1662

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

1663

" No timeout!\n");

1664

}

1665

ret = avahi_simple_poll_iterate(s, -1);

1666

} else {

1667

if(debug){

1668

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

1669

" it, or wait\n");

1670

}

1671

/* the current time */

1672

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1673

if(ret == -1){

1674

perror_plus("clock_gettime");

1675

return -1;

1676

}

1677

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

1678

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

1679

waited_time.tv_sec = (now.tv_sec

1680

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

1681

waited_time.tv_nsec = (now.tv_nsec

1682

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

1683

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

1684

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

1685

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

1686

block_time = ((retry_interval

1687

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

1688

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

1689

1690

if(debug){

1691

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

1692

block_time);

1693

}

1694

1695

if(block_time <= 0){

1696

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

1697

mc->current_server->port,

1698

mc->current_server->if_index,

1699

mc->current_server->af, mc);

1700

if(ret == 0){

1701

avahi_simple_poll_quit(s);

1702

return 0;

1703

}

1704

ret = clock_gettime(CLOCK_MONOTONIC,

1705

&mc->current_server->last_seen);

1706

if(ret == -1){

1707

perror_plus("clock_gettime");

1708

return -1;

1709

}

1710

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

1711

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

1712

servers, but don't block */

1713

}

1714

1715

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

1716

}

1717

if(ret != 0){

1718

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

1719

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

1720

}

1721

}

1722

}

1723

}

1724

1725

__attribute__((nonnull))

1726

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

1727

const float delay){

1728

struct dirent **direntries = NULL;

1729

if(hookdir_fd == -1){

1730

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1731

| O_CLOEXEC);

1732

if(hookdir_fd == -1){

1733

if(errno == ENOENT){

1734

if(debug){

1735

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

1736

" found\n", hookdir);

1737

}

1738

} else {

1739

perror_plus("open");

1740

}

1741

return;

1742

}

1743

}

1744

#ifdef __GLIBC__

1745

#if __GLIBC_PREREQ(2, 15)

1746

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

1747

runnable_hook, alphasort);

1748

#else /* not __GLIBC_PREREQ(2, 15) */

1749

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

1750

alphasort);

1751

#endif /* not __GLIBC_PREREQ(2, 15) */

1752

#else /* not __GLIBC__ */

1753

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

1754

alphasort);

1755

#endif /* not __GLIBC__ */

1756

if(numhooks == -1){

1757

perror_plus("scandir");

1758

return;

1759

}

1760

struct dirent *direntry;

1761

int ret;

1762

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

1763

if(devnull == -1){

1764

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

1765

return;

1766

}

1767

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

1768

direntry = direntries[i];

1769

if(debug){

1770

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

1771

direntry->d_name);

1772

}

1773

pid_t hook_pid = fork();

1774

if(hook_pid == 0){

1775

/* Child */

1776

/* Raise privileges */

1777

errno = raise_privileges_permanently();

1778

if(errno != 0){

1779

perror_plus("Failed to raise privileges");

1780

_exit(EX_NOPERM);

1781

}

1782

/* Set group */

1783

errno = 0;

1784

ret = setgid(0);

1785

if(ret == -1){

1786

perror_plus("setgid");

1787

_exit(EX_NOPERM);

1788

}

1789

/* Reset supplementary groups */

1790

errno = 0;

1791

ret = setgroups(0, NULL);

1792

if(ret == -1){

1793

perror_plus("setgroups");

1794

_exit(EX_NOPERM);

1795

}

1796

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

1797

if(ret == -1){

1798

perror_plus("setenv");

1799

_exit(EX_OSERR);

1800

}

1801

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

1802

if(ret == -1){

1803

perror_plus("setenv");

1804

_exit(EX_OSERR);

1805

}

1806

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

1807

if(ret == -1){

1808

perror_plus("setenv");

1809

_exit(EX_OSERR);

1810

}

1811

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

1812

if(ret == -1){

1813

perror_plus("setenv");

1814

_exit(EX_OSERR);

1815

}

1816

char *delaystring;

1817

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

1818

if(ret == -1){

1819

perror_plus("asprintf");

1820

_exit(EX_OSERR);

1821

}

1822

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

1823

if(ret == -1){

1824

free(delaystring);

1825

perror_plus("setenv");

1826

_exit(EX_OSERR);

1827

}

1828

free(delaystring);

1829

if(connect_to != NULL){

1830

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

1831

if(ret == -1){

1832

perror_plus("setenv");

1833

_exit(EX_OSERR);

1834

}

1835

}

1836

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

1837

direntry->d_name,

1838

O_RDONLY));

1839

if(hook_fd == -1){

1840

perror_plus("openat");

1841

_exit(EXIT_FAILURE);

1842

}

1843

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

1844

perror_plus("close");

1845

_exit(EXIT_FAILURE);

1846

}

1847

ret = dup2(devnull, STDIN_FILENO);

1848

if(ret == -1){

1849

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

1850

_exit(EX_OSERR);

1851

}

1852

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

1853

if(ret == -1){

1854

perror_plus("close");

1855

_exit(EX_OSERR);

1856

}

1857

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1858

if(ret == -1){

1859

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

1860

_exit(EX_OSERR);

1861

}

1862

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

1863

environ) == -1){

1864

perror_plus("fexecve");

1865

_exit(EXIT_FAILURE);

1866

}

1867

} else {

1868

if(hook_pid == -1){

1869

perror_plus("fork");

1870

free(direntry);

1871

continue;

1872

}

1873

int status;

1874

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

1875

perror_plus("waitpid");

1876

free(direntry);

1877

continue;

1878

}

1879

if(WIFEXITED(status)){

1880

if(WEXITSTATUS(status) != 0){

1881

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

1882

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

1883

WEXITSTATUS(status));

1884

free(direntry);

1885

continue;

1886

}

1887

} else if(WIFSIGNALED(status)){

1888

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

1889

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

1890

WTERMSIG(status));

1891

free(direntry);

1892

continue;

1893

} else {

1894

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

1895

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

1896

free(direntry);

1897

continue;

1898

}

1899

}

1900

if(debug){

1901

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

1902

direntry->d_name);

1903

}

1904

free(direntry);

1905

}

1906

free(direntries);

1907

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

1908

perror_plus("close");

1909

} else {

1910

hookdir_fd = -1;

1911

}

1912

close(devnull);

1913

}

1914

1915

__attribute__((nonnull, warn_unused_result))

1916

error_t bring_up_interface(const char *const interface,

1917

const float delay){

1918

error_t old_errno = errno;

1919

int ret;

1920

struct ifreq network;

1921

unsigned int if_index = if_nametoindex(interface);

1922

if(if_index == 0){

1923

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

1924

errno = old_errno;

1925

return ENXIO;

1926

}

1927

1928

if(quit_now){

1929

errno = old_errno;

1930

return EINTR;

1931

}

1932

1933

if(not interface_is_up(interface)){

1934

error_t ret_errno = 0, ioctl_errno = 0;

1935

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

1936

ret_errno = errno;

1937

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

1938

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

1939

errno = old_errno;

1940

return ret_errno;

1941

}

1942

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

1943

1944

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

1945

if(sd == -1){

1946

ret_errno = errno;

1947

perror_plus("socket");

1948

errno = old_errno;

1949

return ret_errno;

1950

}

1951

1952

if(quit_now){

1953

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

1954

if(ret == -1){

1955

perror_plus("close");

1956

}

1957

errno = old_errno;

1958

return EINTR;

1959

}

1960

1961

if(debug){

1962

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

1963

interface);

1964

}

1965

1966

/* Raise privileges */

1967

ret_errno = raise_privileges();

1968

if(ret_errno != 0){

1969

errno = ret_errno;

1970

perror_plus("Failed to raise privileges");

1971

}

1972

1973

#ifdef __linux__

1974

int ret_linux;

1975

bool restore_loglevel = false;

1976

if(ret_errno == 0){

1977

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1978

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

1979

ret_linux = klogctl(8, NULL, 5);

1980

if(ret_linux == -1){

1981

perror_plus("klogctl");

1982

} else {

1983

restore_loglevel = true;

1984

}

1985

}

1986

#endif /* __linux__ */

1987

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

1988

ioctl_errno = errno;

1989

#ifdef __linux__

1990

if(restore_loglevel){

1991

ret_linux = klogctl(7, NULL, 0);

1992

if(ret_linux == -1){

1993

perror_plus("klogctl");

1994

}

1995

}

1996

#endif /* __linux__ */

1997

1998

/* If raise_privileges() succeeded above */

1999

if(ret_errno == 0){

2000

/* Lower privileges */

2001

ret_errno = lower_privileges();

2002

if(ret_errno != 0){

2003

errno = ret_errno;

2004

perror_plus("Failed to lower privileges");

2005

}

2006

}

2007

2008

/* Close the socket */

2009

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

2010

if(ret == -1){

2011

perror_plus("close");

2012

}

2013

2014

if(ret_setflags == -1){

2015

errno = ioctl_errno;

2016

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2017

errno = old_errno;

2018

return ioctl_errno;

2019

}

2020

} else if(debug){

2021

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

2022

interface);

2023

}

2024

2025

/* Sleep checking until interface is running.

2026

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

2027

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

2028

if(interface_is_running(interface)){

1070

2029

break;

1071

2030

}

1072

}

1073

close(flags_fd);

1074

intmax_t tmpmax;

1075

char *tmp;

1076

errno = 0;

1077

tmpmax = strtoimax(flagstring, &tmp, 0);

1078

if(errno != 0 or tmp == flagstring or (*tmp != '\0'

1079

and not (isspace(*tmp)))

1080

or tmpmax != (ifreq_flags)tmpmax){

1081

if(debug){

1082

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1083

flagstring, if_entry->d_name);

1084

}

1085

free(flagstring);

1086

return 0;

1087

}

1088

free(flagstring);

1089

ifreq_flags flags = (ifreq_flags)tmpmax;

1090

/* Reject the loopback device */

1091

if(flags & IFF_LOOPBACK){

1092

if(debug){

1093

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1094

if_entry->d_name);

1095

}

1096

return 0;

1097

}

1098

/* Accept point-to-point devices only if connect_to is specified */

1099

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1100

if(debug){

1101

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1102

if_entry->d_name);

1103

}

1104

return 1;

1105

}

1106

/* Otherwise, reject non-broadcast-capable devices */

1107

if(not (flags & IFF_BROADCAST)){

1108

if(debug){

1109

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1110

if_entry->d_name);

1111

}

1112

return 0;

1113

}

1114

/* Accept this device */

1115

if(debug){

1116

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1117

if_entry->d_name);

1118

}

1119

return 1;

2031

struct timespec sleeptime = { .tv_nsec = 250000000 };

2032

ret = nanosleep(&sleeptime, NULL);

2033

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

2034

perror_plus("nanosleep");

2035

}

2036

}

2037

2038

errno = old_errno;

2039

return 0;

2040

}

2041

2042

__attribute__((nonnull, warn_unused_result))

2043

error_t take_down_interface(const char *const interface){

2044

error_t old_errno = errno;

2045

struct ifreq network;

2046

unsigned int if_index = if_nametoindex(interface);

2047

if(if_index == 0){

2048

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

2049

errno = old_errno;

2050

return ENXIO;

2051

}

2052

if(interface_is_up(interface)){

2053

error_t ret_errno = 0, ioctl_errno = 0;

2054

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

2055

ret_errno = errno;

2056

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

2057

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

2058

errno = old_errno;

2059

return ret_errno;

2060

}

2061

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

2062

2063

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

2064

if(sd == -1){

2065

ret_errno = errno;

2066

perror_plus("socket");

2067

errno = old_errno;

2068

return ret_errno;

2069

}

2070

2071

if(debug){

2072

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

2073

interface);

2074

}

2075

2076

/* Raise privileges */

2077

ret_errno = raise_privileges();

2078

if(ret_errno != 0){

2079

errno = ret_errno;

2080

perror_plus("Failed to raise privileges");

2081

}

2082

2083

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

2084

ioctl_errno = errno;

2085

2086

/* If raise_privileges() succeeded above */

2087

if(ret_errno == 0){

2088

/* Lower privileges */

2089

ret_errno = lower_privileges();

2090

if(ret_errno != 0){

2091

errno = ret_errno;

2092

perror_plus("Failed to lower privileges");

2093

}

2094

}

2095

2096

/* Close the socket */

2097

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

2098

if(ret == -1){

2099

perror_plus("close");

2100

}

2101

2102

if(ret_setflags == -1){

2103

errno = ioctl_errno;

2104

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2105

errno = old_errno;

2106

return ioctl_errno;

2107

}

2108

} else if(debug){

2109

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

2110

interface);

2111

}

2112

2113

errno = old_errno;

2114

return 0;

1120

2115

}

1121

2116

1122

2117

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

2118

mandos_context mc = { .server = NULL, .dh_bits = 1024,

2119

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

2120

"+CTYPE-OPENPGP", .current_server = NULL,

2121

.interfaces = NULL, .interfaces_size = 0 };

1123

2122

AvahiSServiceBrowser *sb = NULL;

1124

int error;

2123

error_t ret_errno;

1125

2124

int ret;

1126

2125

intmax_t tmpmax;

1127

2126

char *tmp;

1128

2127

int exitcode = EXIT_SUCCESS;

1129

const char *interface = "";

1130

struct ifreq network;

1131

int sd = -1;

1132

bool take_down_interface = false;

1133

uid_t uid;

1134

gid_t gid;

1135

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

1136

bool tempdir_created = false;

2128

char *interfaces_to_take_down = NULL;

2129

size_t interfaces_to_take_down_size = 0;

2130

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

2131

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

2132

char *tempdir = NULL;

1137

2133

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1138

2134

const char *seckey = PATHDIR "/" SECKEY;

1139

2135

const char *pubkey = PATHDIR "/" PUBKEY;

2136

char *interfaces_hooks = NULL;

1140

2137

1141

2138

bool gnutls_initialized = false;

1142

2139

bool gpgme_initialized = false;

1143

2140

float delay = 2.5f;

2141

double retry_interval = 10; /* 10s between trying a server and

2142

retrying the same server again */

1144

2143

1145

2144

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

1146

2145

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

1152

2151

errno = 0;

1153

2152

ret = setgid(gid);

1154

2153

if(ret == -1){

1155

perror("setgid");

2154

perror_plus("setgid");

1156

2155

}

1157

2156

1158

2157

/* Lower user privileges (temporarily) */

1159

2158

errno = 0;

1160

2159

ret = seteuid(uid);

1161

2160

if(ret == -1){

1162

perror("seteuid");

2161

perror_plus("seteuid");

1163

2162

}

1164

2163

1165

2164

if(quit_now){

1200

2199

.arg = "SECONDS",

1201

2200

.doc = "Maximum delay to wait for interface startup",

1202

2201

.group = 2 },

2202

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

2203

.arg = "SECONDS",

2204

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

2205

.group = 2 },

2206

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

2207

.arg = "DIR",

2208

.doc = "Directory where network hooks are located",

2209

.group = 2 },

1203

2210

/*

1204

2211

* These reproduce what we would get without ARGP_NO_HELP

1205

2212

*/

1223

2230

connect_to = arg;

1224

2231

break;

1225

2232

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

1226

interface = arg;

2233

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

2234

arg, (int)',');

2235

if(ret_errno != 0){

2236

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

2237

}

1227

2238

break;

1228

2239

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

1229

2240

seckey = arg;

1249

2260

if(errno != 0 or tmp == arg or *tmp != '\0'){

1250

2261

argp_error(state, "Bad delay");

1251

2262

}

2263

case 132: /* --retry */

2264

errno = 0;

2265

retry_interval = strtod(arg, &tmp);

2266

if(errno != 0 or tmp == arg or *tmp != '\0'

2267

or (retry_interval * 1000) > INT_MAX

2268

or retry_interval < 0){

2269

argp_error(state, "Bad retry interval");

2270

}

2271

break;

2272

case 133: /* --network-hook-dir */

2273

hookdir = arg;

1252

2274

break;

1253

2275

/*

1254

2276

* These reproduce what we would get without ARGP_NO_HELP

1261

2283

argp_state_help(state, state->out_stream,

1262

2284

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1263

2285

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

1264

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

2286

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

1265

2287

exit(argp_err_exit_status);

1266

2288

break;

1267

2289

default:

1282

2304

case ENOMEM:

1283

2305

default:

1284

2306

errno = ret;

1285

perror("argp_parse");

2307

perror_plus("argp_parse");

1286

2308

exitcode = EX_OSERR;

1287

2309

goto end;

1288

2310

case EINVAL:

1291

2313

}

1292

2314

}

1293

2315

2316

{

2317

/* Work around Debian bug #633582:

2318

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

2319

2320

/* Re-raise privileges */

2321

ret_errno = raise_privileges();

2322

if(ret_errno != 0){

2323

errno = ret_errno;

2324

perror_plus("Failed to raise privileges");

2325

} else {

2326

struct stat st;

2327

2328

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

2329

int seckey_fd = open(seckey, O_RDONLY);

2330

if(seckey_fd == -1){

2331

perror_plus("open");

2332

} else {

2333

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

2334

if(ret == -1){

2335

perror_plus("fstat");

2336

} else {

2337

if(S_ISREG(st.st_mode)

2338

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

2339

ret = fchown(seckey_fd, uid, gid);

2340

if(ret == -1){

2341

perror_plus("fchown");

2342

}

2343

}

2344

}

2345

TEMP_FAILURE_RETRY(close(seckey_fd));

2346

}

2347

}

2348

2349

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

2350

int pubkey_fd = open(pubkey, O_RDONLY);

2351

if(pubkey_fd == -1){

2352

perror_plus("open");

2353

} else {

2354

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

2355

if(ret == -1){

2356

perror_plus("fstat");

2357

} else {

2358

if(S_ISREG(st.st_mode)

2359

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

2360

ret = fchown(pubkey_fd, uid, gid);

2361

if(ret == -1){

2362

perror_plus("fchown");

2363

}

2364

}

2365

}

2366

TEMP_FAILURE_RETRY(close(pubkey_fd));

2367

}

2368

}

2369

2370

/* Lower privileges */

2371

ret_errno = lower_privileges();

2372

if(ret_errno != 0){

2373

errno = ret_errno;

2374

perror_plus("Failed to lower privileges");

2375

}

2376

}

2377

}

2378

2379

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

2380

{

2381

char *interface = NULL;

2382

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

2383

interface))){

2384

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

2385

and if_nametoindex(interface) == 0){

2386

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

2387

fprintf_plus(stderr, "Not using nonexisting interface"

2388

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

2389

}

2390

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

2391

interface = NULL;

2392

}

2393

}

2394

}

2395

2396

/* Run network hooks */

2397

{

2398

if(mc.interfaces != NULL){

2399

interfaces_hooks = malloc(mc.interfaces_size);

2400

if(interfaces_hooks == NULL){

2401

perror_plus("malloc");

2402

goto end;

2403

}

2404

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

2405

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

2406

}

2407

run_network_hooks("start", interfaces_hooks != NULL ?

2408

interfaces_hooks : "", delay);

2409

}

2410

1294

2411

if(not debug){

1295

2412

avahi_set_log_function(empty_log);

1296

2413

}

1297

1298

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

1299

struct dirent **direntries;

1300

ret = scandir(sys_class_net, &direntries, good_interface,

1301

alphasort);

1302

if(ret >= 1){

1303

/* Pick the first good interface */

1304

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

1305

if(debug){

1306

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

1307

}

1308

if(interface == NULL){

1309

perror("malloc");

1310

free(direntries);

1311

exitcode = EXIT_FAILURE;

1312

goto end;

1313

}

1314

free(direntries);

1315

} else {

1316

free(direntries);

1317

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

1318

exitcode = EXIT_FAILURE;

1319

goto end;

1320

}

1321

}

1322

2414

1323

2415

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

1324

2416

from the signal handler */

1325

2417

/* Initialize the pseudo-RNG for Avahi */

1326

2418

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

1327

mc.simple_poll = avahi_simple_poll_new();

1328

if(mc.simple_poll == NULL){

1329

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

2419

simple_poll = avahi_simple_poll_new();

2420

if(simple_poll == NULL){

2421

fprintf_plus(stderr,

2422

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

1330

2423

exitcode = EX_UNAVAILABLE;

1331

2424

goto end;

1332

2425

}

1334

2427

sigemptyset(&sigterm_action.sa_mask);

1335

2428

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1336

2429

if(ret == -1){

1337

perror("sigaddset");

2430

perror_plus("sigaddset");

1338

2431

exitcode = EX_OSERR;

1339

2432

goto end;

1340

2433

}

1341

2434

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1342

2435

if(ret == -1){

1343

perror("sigaddset");

2436

perror_plus("sigaddset");

1344

2437

exitcode = EX_OSERR;

1345

2438

goto end;

1346

2439

}

1347

2440

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1348

2441

if(ret == -1){

1349

perror("sigaddset");

2442

perror_plus("sigaddset");

1350

2443

exitcode = EX_OSERR;

1351

2444

goto end;

1352

2445

}

1356

2449

*/

1357

2450

ret = sigaction(SIGINT, NULL, &old_sigterm_action);

1358

2451

if(ret == -1){

1359

perror("sigaction");

2452

perror_plus("sigaction");

1360

2453

return EX_OSERR;

1361

2454

}

1362

2455

if(old_sigterm_action.sa_handler != SIG_IGN){

1363

2456

ret = sigaction(SIGINT, &sigterm_action, NULL);

1364

2457

if(ret == -1){

1365

perror("sigaction");

2458

perror_plus("sigaction");

1366

2459

exitcode = EX_OSERR;

1367

2460

goto end;

1368

2461

}

1369

2462

}

1370

2463

ret = sigaction(SIGHUP, NULL, &old_sigterm_action);

1371

2464

if(ret == -1){

1372

perror("sigaction");

2465

perror_plus("sigaction");

1373

2466

return EX_OSERR;

1374

2467

}

1375

2468

if(old_sigterm_action.sa_handler != SIG_IGN){

1376

2469

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1377

2470

if(ret == -1){

1378

perror("sigaction");

2471

perror_plus("sigaction");

1379

2472

exitcode = EX_OSERR;

1380

2473

goto end;

1381

2474

}

1382

2475

}

1383

2476

ret = sigaction(SIGTERM, NULL, &old_sigterm_action);

1384

2477

if(ret == -1){

1385

perror("sigaction");

2478

perror_plus("sigaction");

1386

2479

return EX_OSERR;

1387

2480

}

1388

2481

if(old_sigterm_action.sa_handler != SIG_IGN){

1389

2482

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1390

2483

if(ret == -1){

1391

perror("sigaction");

1392

exitcode = EX_OSERR;

1393

goto end;

1394

}

1395

}

1396

1397

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

1398

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

1399

if_index = (AvahiIfIndex) if_nametoindex(interface);

1400

if(if_index == 0){

1401

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

1402

exitcode = EX_UNAVAILABLE;

1403

goto end;

1404

}

1405

1406

if(quit_now){

1407

goto end;

1408

}

1409

1410

/* Re-raise priviliges */

1411

errno = 0;

1412

ret = seteuid(0);

1413

if(ret == -1){

1414

perror("seteuid");

1415

}

1416

1417

#ifdef __linux__

1418

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1419

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

1420

ret = klogctl(8, NULL, 5);

1421

bool restore_loglevel = true;

1422

if(ret == -1){

1423

restore_loglevel = false;

1424

perror("klogctl");

1425

}

1426

#endif /* __linux__ */

1427

1428

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1429

if(sd < 0){

1430

perror("socket");

1431

exitcode = EX_OSERR;

1432

#ifdef __linux__

1433

if(restore_loglevel){

1434

ret = klogctl(7, NULL, 0);

1435

if(ret == -1){

1436

perror("klogctl");

1437

}

1438

}

1439

#endif /* __linux__ */

1440

/* Lower privileges */

1441

errno = 0;

1442

ret = seteuid(uid);

1443

if(ret == -1){

1444

perror("seteuid");

1445

}

1446

goto end;

1447

}

1448

strcpy(network.ifr_name, interface);

1449

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

1450

if(ret == -1){

1451

perror("ioctl SIOCGIFFLAGS");

1452

#ifdef __linux__

1453

if(restore_loglevel){

1454

ret = klogctl(7, NULL, 0);

1455

if(ret == -1){

1456

perror("klogctl");

1457

}

1458

}

1459

#endif /* __linux__ */

1460

exitcode = EX_OSERR;

1461

/* Lower privileges */

1462

errno = 0;

1463

ret = seteuid(uid);

1464

if(ret == -1){

1465

perror("seteuid");

1466

}

1467

goto end;

1468

}

1469

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

1470

network.ifr_flags |= IFF_UP;

1471

take_down_interface = true;

1472

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

1473

if(ret == -1){

1474

take_down_interface = false;

1475

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1476

exitcode = EX_OSERR;

1477

#ifdef __linux__

1478

if(restore_loglevel){

1479

ret = klogctl(7, NULL, 0);

1480

if(ret == -1){

1481

perror("klogctl");

2484

perror_plus("sigaction");

2485

exitcode = EX_OSERR;

2486

goto end;

2487

}

2488

}

2489

2490

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

2491

if(mc.interfaces == NULL){

2492

struct dirent **direntries = NULL;

2493

/* Look for any good interfaces */

2494

ret = scandir(sys_class_net, &direntries, good_interface,

2495

alphasort);

2496

if(ret >= 1){

2497

/* Add all found interfaces to interfaces list */

2498

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

2499

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

2500

direntries[i]->d_name);

2501

if(ret_errno != 0){

2502

errno = ret_errno;

2503

perror_plus("argz_add");

2504

free(direntries[i]);

2505

continue;

2506

}

2507

if(debug){

2508

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

2509

direntries[i]->d_name);

2510

}

2511

free(direntries[i]);

2512

}

2513

free(direntries);

2514

} else {

2515

if(ret == 0){

2516

free(direntries);

2517

}

2518

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

2519

exitcode = EXIT_FAILURE;

2520

goto end;

2521

}

2522

}

2523

2524

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

2525

{

2526

char *interface = NULL;

2527

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

2528

interface))){

2529

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

2530

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

2531

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

2532

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

2533

interface);

2534

interface = NULL;

2535

while((interface = argz_next(mc.interfaces,

2536

mc.interfaces_size, interface))){

2537

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

2538

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

2539

interface);

2540

interface = NULL;

1482

2541

}

1483

2542

}

1484

#endif /* __linux__ */

1485

/* Lower privileges */

1486

errno = 0;

1487

ret = seteuid(uid);

1488

if(ret == -1){

1489

perror("seteuid");

1490

}

1491

goto end;

1492

}

1493

}

1494

/* sleep checking until interface is running */

1495

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

1496

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

1497

if(ret == -1){

1498

perror("ioctl SIOCGIFFLAGS");

1499

} else if(network.ifr_flags & IFF_RUNNING){

1500

2543

break;

1501

2544

}

1502

struct timespec sleeptime = { .tv_nsec = 250000000 };

1503

ret = nanosleep(&sleeptime, NULL);

1504

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

1505

perror("nanosleep");

1506

}

1507

}

1508

if(not take_down_interface){

1509

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

1510

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

1511

if(ret == -1){

1512

perror("close");

1513

}

1514

}

1515

#ifdef __linux__

1516

if(restore_loglevel){

1517

/* Restores kernel loglevel to default */

1518

ret = klogctl(7, NULL, 0);

1519

if(ret == -1){

1520

perror("klogctl");

1521

}

1522

}

1523

#endif /* __linux__ */

1524

/* Lower privileges */

1525

errno = 0;

1526

if(take_down_interface){

1527

/* Lower privileges */

1528

ret = seteuid(uid);

1529

if(ret == -1){

1530

perror("seteuid");

1531

}

1532

} else {

1533

/* Lower privileges permanently */

1534

ret = setuid(uid);

1535

if(ret == -1){

1536

perror("setuid");

1537

}

1538

}

2545

bool interface_was_up = interface_is_up(interface);

2546

errno = bring_up_interface(interface, delay);

2547

if(not interface_was_up){

2548

if(errno != 0){

2549

perror_plus("Failed to bring up interface");

2550

} else {

2551

errno = argz_add(&interfaces_to_take_down,

2552

&interfaces_to_take_down_size,

2553

interface);

2554

if(errno != 0){

2555

perror_plus("argz_add");

2556

}

2557

}

2558

}

2559

}

2560

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

2561

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

2562

}

2563

}

2564

2565

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

2566

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

2567

if(debug){

2568

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

2569

mc.interfaces);

2570

}

2571

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

1539

2572

}

1540

2573

1541

2574

if(quit_now){

1542

2575

goto end;

1543

2576

}

1544

2577

1545

ret = init_gnutls_global(pubkey, seckey);

2578

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

1546

2579

if(ret == -1){

1547

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

2580

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

1548

2581

exitcode = EX_UNAVAILABLE;

1549

2582

goto end;

1550

2583

} else {

1555

2588

goto end;

1556

2589

}

1557

2590

1558

tempdir_created = true;

1559

if(mkdtemp(tempdir) == NULL){

1560

tempdir_created = false;

1561

perror("mkdtemp");

2591

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

2592

tempdir = mkdtemp(run_tempdir);

2593

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

2594

if(debug){

2595

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

2596

run_tempdir, old_tempdir);

2597

}

2598

tempdir = mkdtemp(old_tempdir);

2599

}

2600

if(tempdir == NULL){

2601

perror_plus("mkdtemp");

1562

2602

goto end;

1563

2603

}

1564

2604

1566

2606

goto end;

1567

2607

}

1568

2608

1569

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

1570

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

2609

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

2610

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

1571

2611

exitcode = EX_UNAVAILABLE;

1572

2612

goto end;

1573

2613

} else {

1582

2622

/* Connect directly, do not use Zeroconf */

1583

2623

/* (Mainly meant for debugging) */

1584

2624

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

2625

1585

2626

if(address == NULL){

1586

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

2627

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

1587

2628

exitcode = EX_USAGE;

1588

2629

goto end;

1589

2630

}

1592

2633

goto end;

1593

2634

}

1594

2635

1595

uint16_t port;

2636

in_port_t port;

1596

2637

errno = 0;

1597

2638

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

1598

2639

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

1599

or tmpmax != (uint16_t)tmpmax){

1600

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

2640

or tmpmax != (in_port_t)tmpmax){

2641

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

1601

2642

exitcode = EX_USAGE;

1602

2643

goto end;

1603

2644

}

1604

2645

1605

2646

if(quit_now){

1606

2647

goto end;

1607

2648

}

1608

2649

1609

port = (uint16_t)tmpmax;

2650

port = (in_port_t)tmpmax;

1610

2651

*address = '\0';

1611

address = connect_to;

1612

2652

/* Colon in address indicates IPv6 */

1613

2653

int af;

1614

if(strchr(address, ':') != NULL){

2654

if(strchr(connect_to, ':') != NULL){

1615

2655

af = AF_INET6;

2656

/* Accept [] around IPv6 address - see RFC 5952 */

2657

if(connect_to[0] == '[' and address[-1] == ']')

2658

{

2659

connect_to++;

2660

address[-1] = '\0';

2661

}

1616

2662

} else {

1617

2663

af = AF_INET;

1618

2664

}

2665

address = connect_to;

1619

2666

1620

2667

if(quit_now){

1621

2668

goto end;

1622

2669

}

1623

2670

1624

2671

while(not quit_now){

1625

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

2672

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

2673

&mc);

1626

2674

if(quit_now or ret == 0){

1627

2675

break;

1628

2676

}

1629

sleep(15);

1630

};

1631

1632

if (not quit_now){

2677

if(debug){

2678

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

2679

(int)retry_interval);

2680

}

2681

sleep((unsigned int)retry_interval);

2682

}

2683

2684

if(not quit_now){

1633

2685

exitcode = EXIT_SUCCESS;

1634

2686

}

1635

2687

1636

2688

goto end;

1637

2689

}

1638

2690

1650

2702

config.publish_domain = 0;

1651

2703

1652

2704

/* Allocate a new server */

1653

mc.server = avahi_server_new(avahi_simple_poll_get

1654

(mc.simple_poll), &config, NULL,

1655

NULL, &error);

2705

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2706

&config, NULL, NULL, &ret_errno);

1656

2707

1657

2708

/* Free the Avahi configuration data */

1658

2709

avahi_server_config_free(&config);

1660

2711

1661

2712

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

1662

2713

if(mc.server == NULL){

1663

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

1664

avahi_strerror(error));

2714

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

2715

avahi_strerror(ret_errno));

1665

2716

exitcode = EX_UNAVAILABLE;

1666

2717

goto end;

1667

2718

}

1673

2724

/* Create the Avahi service browser */

1674

2725

sb = avahi_s_service_browser_new(mc.server, if_index,

1675

2726

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1676

NULL, 0, browse_callback, NULL);

2727

NULL, 0, browse_callback,

2728

(void *)&mc);

1677

2729

if(sb == NULL){

1678

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

1679

avahi_strerror(avahi_server_errno(mc.server)));

2730

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

2731

avahi_strerror(avahi_server_errno(mc.server)));

1680

2732

exitcode = EX_UNAVAILABLE;

1681

2733

goto end;

1682

2734

}

1688

2740

/* Run the main loop */

1689

2741

1690

2742

if(debug){

1691

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

2743

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

1692

2744

}

1693

2745

1694

avahi_simple_poll_loop(mc.simple_poll);

2746

ret = avahi_loop_with_timeout(simple_poll,

2747

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

2748

if(debug){

2749

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

2750

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

2751

}

1695

2752

1696

2753

end:

1697

2754

1698

2755

if(debug){

1699

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

2756

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

1700

2757

}

1701

2758

1702

2759

/* Cleanup things */

2760

free(mc.interfaces);

2761

1703

2762

if(sb != NULL)

1704

2763

avahi_s_service_browser_free(sb);

1705

2764

1706

2765

if(mc.server != NULL)

1707

2766

avahi_server_free(mc.server);

1708

2767

1709

if(mc.simple_poll != NULL)

1710

avahi_simple_poll_free(mc.simple_poll);

2768

if(simple_poll != NULL)

2769

avahi_simple_poll_free(simple_poll);

1711

2770

1712

2771

if(gnutls_initialized){

1713

2772

gnutls_certificate_free_credentials(mc.cred);

1719

2778

gpgme_release(mc.ctx);

1720

2779

}

1721

2780

1722

/* Take down the network interface */

1723

if(take_down_interface){

1724

/* Re-raise priviliges */

1725

errno = 0;

1726

ret = seteuid(0);

1727

if(ret == -1){

1728

perror("seteuid");

1729

}

1730

if(geteuid() == 0){

1731

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

1732

if(ret == -1){

1733

perror("ioctl SIOCGIFFLAGS");

1734

} else if(network.ifr_flags & IFF_UP) {

1735

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

1736

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

1737

if(ret == -1){

1738

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1739

}

1740

}

1741

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

1742

if(ret == -1){

1743

perror("close");

1744

}

1745

/* Lower privileges permanently */

1746

errno = 0;

1747

ret = setuid(uid);

1748

if(ret == -1){

1749

perror("setuid");

1750

}

1751

}

1752

}

1753

1754

/* Removes the temp directory used by GPGME */

1755

if(tempdir_created){

1756

DIR *d;

1757

struct dirent *direntry;

1758

d = opendir(tempdir);

1759

if(d == NULL){

1760

if(errno != ENOENT){

1761

perror("opendir");

1762

}

1763

} else {

1764

while(true){

1765

direntry = readdir(d);

1766

if(direntry == NULL){

1767

break;

1768

}

1769

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

1770

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

1771

and (direntry->d_name[1] == '\0'

1772

or (direntry->d_name[1] == '.'

1773

and direntry->d_name[2] == '\0'))){

1774

continue;

1775

}

1776

char *fullname = NULL;

1777

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

1778

direntry->d_name);

1779

if(ret < 0){

1780

perror("asprintf");

1781

continue;

1782

}

1783

ret = remove(fullname);

1784

if(ret == -1){

1785

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

1786

strerror(errno));

1787

}

1788

free(fullname);

1789

}

1790

closedir(d);

1791

}

1792

ret = rmdir(tempdir);

1793

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

1794

perror("rmdir");

2781

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

2782

has seen */

2783

if(mc.current_server != NULL){

2784

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

2785

while(mc.current_server != NULL){

2786

server *next = mc.current_server->next;

2787

#ifdef __GNUC__

2788

#pragma GCC diagnostic push

2789

#pragma GCC diagnostic ignored "-Wcast-qual"

2790

#endif

2791

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

2792

#ifdef __GNUC__

2793

#pragma GCC diagnostic pop

2794

#endif

2795

free(mc.current_server);

2796

mc.current_server = next;

2797

}

2798

}

2799

2800

/* Re-raise privileges */

2801

{

2802

ret_errno = raise_privileges();

2803

if(ret_errno != 0){

2804

errno = ret_errno;

2805

perror_plus("Failed to raise privileges");

2806

} else {

2807

2808

/* Run network hooks */

2809

run_network_hooks("stop", interfaces_hooks != NULL ?

2810

interfaces_hooks : "", delay);

2811

2812

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

2813

{

2814

char *interface = NULL;

2815

while((interface=argz_next(interfaces_to_take_down,

2816

interfaces_to_take_down_size,

2817

interface))){

2818

ret_errno = take_down_interface(interface);

2819

if(ret_errno != 0){

2820

errno = ret_errno;

2821

perror_plus("Failed to take down interface");

2822

}

2823

}

2824

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

2825

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

2826

" down\n");

2827

}

2828

}

2829

}

2830

2831

ret_errno = lower_privileges_permanently();

2832

if(ret_errno != 0){

2833

errno = ret_errno;

2834

perror_plus("Failed to lower privileges permanently");

2835

}

2836

}

2837

2838

free(interfaces_to_take_down);

2839

free(interfaces_hooks);

2840

2841

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

2842

if(tempdir != NULL){

2843

struct dirent **direntries = NULL;

2844

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY

2845

| O_NOFOLLOW

2846

| O_DIRECTORY

2847

| O_PATH));

2848

if(tempdir_fd == -1){

2849

perror_plus("open");

2850

} else {

2851

#ifdef __GLIBC__

2852

#if __GLIBC_PREREQ(2, 15)

2853

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

2854

notdotentries, alphasort);

2855

#else /* not __GLIBC_PREREQ(2, 15) */

2856

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

2857

alphasort);

2858

#endif /* not __GLIBC_PREREQ(2, 15) */

2859

#else /* not __GLIBC__ */

2860

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

2861

alphasort);

2862

#endif /* not __GLIBC__ */

2863

if(numentries >= 0){

2864

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

2865

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

2866

if(ret == -1){

2867

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

2868

" \"%s\", 0): %s\n", tempdir,

2869

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

2870

}

2871

free(direntries[i]);

2872

}

2873

2874

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

2875

free(direntries);

2876

if(numentries == -1){

2877

perror_plus("scandir");

2878

}

2879

ret = rmdir(tempdir);

2880

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

2881

perror_plus("rmdir");

2882

}

2883

}

2884

TEMP_FAILURE_RETRY(close(tempdir_fd));

1795

2885

}

1796

2886

}

1797

2887

1802

2892

&old_sigterm_action,

1803

2893

NULL));

1804

2894

if(ret == -1){

1805

perror("sigaction");

2895

perror_plus("sigaction");

1806

2896

}

1807

2897

do {

1808

2898

ret = raise(signal_received);

1809

2899

} while(ret != 0 and errno == EINTR);

1810

2900

if(ret != 0){

1811

perror("raise");

2901

perror_plus("raise");

1812

2902

abort();

1813

2903

}

1814

2904

TEMP_FAILURE_RETRY(pause());