/mandos/release : revision 237.7.431

9

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

10

*

11

* Everything else is

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13

12

13

14

*

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

39

40

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

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

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stdout, ferror(), remove() */

44

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

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stdout, ferror() */

44

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

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

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

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strtof(), abort() */

48

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

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

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

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

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asprintf(), strncpy(), strsignal()

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*/

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52

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

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53

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

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sockaddr_in6, PF_INET6,

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opendir(), DIR */

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

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

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inet_pton(), connect() */

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

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inet_pton(), connect(),

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getnameinfo() */

61

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

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62

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

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63

*/

62

64

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

63

65

strtoimax() */

64

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

65

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

66

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

66

71

program_invocation_short_name */

67

72

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

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73

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

73

78

*/

74

79

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

75

80

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

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

77

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

81

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

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unlinkat() */

83

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

78

84

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

79

85

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

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86

argp_state, struct argp,

88

94

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

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95

WEXITSTATUS(), WTERMSIG() */

90

96

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

97

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

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

100

argz_count() */

101

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

102

EAI_SYSTEM, gai_strerror() */

91

103

92

104

#ifdef __linux__

93

105

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

135

147

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

136

148

char *connect_to = NULL;

137

149

const char *hookdir = HOOKDIR;

150

int hookdir_fd = -1;

151

uid_t uid = 65534;

152

gid_t gid = 65534;

138

153

139

154

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

140

155

typedef struct server{

141

156

const char *ip;

142

uint16_t port;

157

in_port_t port;

143

158

AvahiIfIndex if_index;

144

159

int af;

145

160

struct timespec last_seen;

149

164

150

165

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

151

166

typedef struct {

152

AvahiSimplePoll *simple_poll;

153

167

AvahiServer *server;

154

168

gnutls_certificate_credentials_t cred;

155

169

unsigned int dh_bits;

157

171

const char *priority;

158

172

gpgme_ctx_t ctx;

159

173

server *current_server;

174

char *interfaces;

175

size_t interfaces_size;

160

176

} mandos_context;

161

177

162

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

163

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

164

.dh_bits = 1024, .priority = "SECURE256"

165

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

166

.current_server = NULL };

178

/* global so signal handler can reach it*/

179

AvahiSimplePoll *simple_poll;

167

180

168

181

sig_atomic_t quit_now = 0;

169

182

int signal_received = 0;

170

183

171

184

/* Function to use when printing errors */

172

185

void perror_plus(const char *print_text){

186

int e = errno;

173

187

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

174

188

program_invocation_short_name);

189

errno = e;

175

190

perror(print_text);

176

191

}

177

192

193

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

178

194

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

179

195

va_list ap;

180

196

va_start (ap, format);

181

197

182

198

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

183

199

program_invocation_short_name));

184

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

200

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

185

201

}

186

202

187

203

/*

189

205

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

190

206

* "buffer_length" is how much is already used.

191

207

*/

208

__attribute__((nonnull, warn_unused_result))

192

209

size_t incbuffer(char **buffer, size_t buffer_length,

193

210

size_t buffer_capacity){

194

211

if(buffer_length + BUFFER_SIZE > buffer_capacity){

195

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

196

if(buffer == NULL){

212

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

213

if(new_buf == NULL){

214

int old_errno = errno;

215

free(*buffer);

216

errno = old_errno;

217

*buffer = NULL;

197

218

return 0;

198

219

}

220

*buffer = new_buf;

199

221

buffer_capacity += BUFFER_SIZE;

200

222

}

201

223

return buffer_capacity;

202

224

}

203

225

204

226

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

205

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

206

int af){

227

__attribute__((nonnull, warn_unused_result))

228

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

229

int af, server **current_server){

207

230

int ret;

208

231

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

209

232

if(new_server == NULL){

210

233

perror_plus("malloc");

211

return -1;

234

return false;

212

235

}

213

236

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

214

237

.port = port,

216

239

.af = af };

217

240

if(new_server->ip == NULL){

218

241

perror_plus("strdup");

219

return -1;

242

free(new_server);

243

return false;

244

}

245

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

246

if(ret == -1){

247

perror_plus("clock_gettime");

248

#ifdef __GNUC__

249

#pragma GCC diagnostic push

250

#pragma GCC diagnostic ignored "-Wcast-qual"

251

#endif

252

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

253

#ifdef __GNUC__

254

#pragma GCC diagnostic pop

255

#endif

256

free(new_server);

257

return false;

220

258

}

221

259

/* Special case of first server */

222

if (mc.current_server == NULL){

260

if(*current_server == NULL){

223

261

new_server->next = new_server;

224

262

new_server->prev = new_server;

225

mc.current_server = new_server;

226

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

263

*current_server = new_server;

227

264

} else {

228

new_server->next = mc.current_server;

229

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

265

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

266

new_server->next = *current_server;

267

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

230

268

new_server->prev->next = new_server;

231

mc.current_server->prev = new_server;

232

}

233

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

234

if(ret == -1){

235

perror_plus("clock_gettime");

236

return -1;

237

}

238

return 0;

269

(*current_server)->prev = new_server;

270

}

271

return true;

239

272

}

240

273

241

274

/*

242

275

* Initialize GPGME.

243

276

*/

244

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

245

const char *tempdir){

277

__attribute__((nonnull, warn_unused_result))

278

static bool init_gpgme(const char * const seckey,

279

const char * const pubkey,

280

const char * const tempdir,

281

mandos_context *mc){

246

282

gpgme_error_t rc;

247

283

gpgme_engine_info_t engine_info;

248

284

249

250

285

/*

251

286

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

252

287

*/

253

bool import_key(const char *filename){

288

bool import_key(const char * const filename){

254

289

int ret;

255

290

int fd;

256

291

gpgme_data_t pgp_data;

268

303

return false;

269

304

}

270

305

271

rc = gpgme_op_import(mc.ctx, pgp_data);

306

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

272

307

if(rc != GPG_ERR_NO_ERROR){

273

308

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

274

309

gpgme_strsource(rc), gpgme_strerror(rc));

275

310

return false;

276

311

}

277

312

278

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

313

ret = close(fd);

279

314

if(ret == -1){

280

315

perror_plus("close");

281

316

}

318

353

}

319

354

320

355

/* Create new GPGME "context" */

321

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

356

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

322

357

if(rc != GPG_ERR_NO_ERROR){

323

358

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

324

359

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

337

372

* Decrypt OpenPGP data.

338

373

* Returns -1 on error

339

374

*/

375

__attribute__((nonnull, warn_unused_result))

340

376

static ssize_t pgp_packet_decrypt(const char *cryptotext,

341

377

size_t crypto_size,

342

char **plaintext){

378

char **plaintext,

379

mandos_context *mc){

343

380

gpgme_data_t dh_crypto, dh_plain;

344

381

gpgme_error_t rc;

345

382

ssize_t ret;

371

408

372

409

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

373

410

data buffer */

374

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

411

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

375

412

if(rc != GPG_ERR_NO_ERROR){

376

413

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

377

414

gpgme_strsource(rc), gpgme_strerror(rc));

378

415

plaintext_length = -1;

379

416

if(debug){

380

417

gpgme_decrypt_result_t result;

381

result = gpgme_op_decrypt_result(mc.ctx);

418

result = gpgme_op_decrypt_result(mc->ctx);

382

419

if(result == NULL){

383

420

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

384

421

} else {

461

498

return plaintext_length;

462

499

}

463

500

464

static const char * safer_gnutls_strerror(int value){

465

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

466

-Wunreachable-code */

467

if(ret == NULL)

468

ret = "(unknown)";

469

return ret;

501

__attribute__((warn_unused_result, const))

502

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

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

508

__attribute__((warn_unused_result))

509

static const char *safer_gnutls_strerror(int value){

510

const char *ret = gnutls_strerror(value);

511

return safe_string(ret);

470

512

}

471

513

472

514

/* GnuTLS log function callback */

515

__attribute__((nonnull))

473

516

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

474

517

const char* string){

475

518

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

476

519

}

477

520

521

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

478

522

static int init_gnutls_global(const char *pubkeyfilename,

479

const char *seckeyfilename){

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

mandos_context *mc){

480

526

int ret;

527

unsigned int uret;

481

528

482

529

if(debug){

483

530

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

484

531

}

485

532

486

ret = gnutls_global_init();

487

if(ret != GNUTLS_E_SUCCESS){

488

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

489

safer_gnutls_strerror(ret));

490

return -1;

491

}

492

493

533

if(debug){

494

534

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

495

535

* - GnuTLS manual

499

539

}

500

540

501

541

/* OpenPGP credentials */

502

ret = gnutls_certificate_allocate_credentials(&mc.cred);

542

ret = gnutls_certificate_allocate_credentials(&mc->cred);

503

543

if(ret != GNUTLS_E_SUCCESS){

504

544

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

505

545

safer_gnutls_strerror(ret));

506

gnutls_global_deinit();

507

546

return -1;

508

547

}

509

548

515

554

}

516

555

517

556

ret = gnutls_certificate_set_openpgp_key_file

518

(mc.cred, pubkeyfilename, seckeyfilename,

557

(mc->cred, pubkeyfilename, seckeyfilename,

519

558

GNUTLS_OPENPGP_FMT_BASE64);

520

559

if(ret != GNUTLS_E_SUCCESS){

521

560

fprintf_plus(stderr,

527

566

}

528

567

529

568

/* GnuTLS server initialization */

530

ret = gnutls_dh_params_init(&mc.dh_params);

569

ret = gnutls_dh_params_init(&mc->dh_params);

531

570

if(ret != GNUTLS_E_SUCCESS){

532

571

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

533

572

" initialization: %s\n",

534

573

safer_gnutls_strerror(ret));

535

574

goto globalfail;

536

575

}

537

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

538

if(ret != GNUTLS_E_SUCCESS){

539

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

540

safer_gnutls_strerror(ret));

541

goto globalfail;

542

}

543

544

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

576

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

577

if(dhparamsfilename != NULL){

578

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

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

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

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

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

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

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

625

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

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

free(params.data);

630

} while(false);

631

}

632

if(dhparamsfilename == NULL){

633

if(mc->dh_bits == 0){

634

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

635

/* Try to read the private key file */

636

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

637

do {

638

int secfile = open(seckeyfilename, O_RDONLY);

639

if(secfile == -1){

640

perror_plus("open");

641

break;

642

}

643

size_t buffer_capacity = 0;

644

while(true){

645

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

646

(size_t)buffer.size,

647

(size_t)buffer_capacity);

648

if(buffer_capacity == 0){

649

perror_plus("incbuffer");

650

free(buffer.data);

651

buffer.data = NULL;

652

break;

653

}

654

ssize_t bytes_read = read(secfile,

655

buffer.data + buffer.size,

656

BUFFER_SIZE);

657

/* EOF */

658

if(bytes_read == 0){

659

break;

660

}

661

/* check bytes_read for failure */

662

if(bytes_read < 0){

663

perror_plus("read");

664

free(buffer.data);

665

buffer.data = NULL;

666

break;

667

}

668

buffer.size += (unsigned int)bytes_read;

669

}

670

close(secfile);

671

} while(false);

672

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

673

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

674

if(buffer.data != NULL){

675

{

676

gnutls_openpgp_privkey_t privkey = NULL;

677

ret = gnutls_openpgp_privkey_init(&privkey);

678

if(ret != GNUTLS_E_SUCCESS){

679

fprintf_plus(stderr, "Error initializing OpenPGP key"

680

" structure: %s",

681

safer_gnutls_strerror(ret));

682

free(buffer.data);

683

buffer.data = NULL;

684

} else {

685

ret = gnutls_openpgp_privkey_import

686

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

687

if(ret != GNUTLS_E_SUCCESS){

688

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

689

safer_gnutls_strerror(ret));

690

privkey = NULL;

691

}

692

free(buffer.data);

693

buffer.data = NULL;

694

if(privkey != NULL){

695

/* Use private key to suggest an appropriate

696

sec_param */

697

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

698

gnutls_openpgp_privkey_deinit(privkey);

699

if(debug){

700

fprintf_plus(stderr, "This OpenPGP key implies using"

701

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

702

safe_string(gnutls_sec_param_get_name

703

(sec_param)));

704

}

705

}

706

}

707

}

708

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

709

/* Err on the side of caution */

710

sec_param = GNUTLS_SEC_PARAM_ULTRA;

711

if(debug){

712

fprintf_plus(stderr, "Falling back to security parameter"

713

" \"%s\"\n",

714

safe_string(gnutls_sec_param_get_name

715

(sec_param)));

716

}

717

}

718

}

719

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

720

if(uret != 0){

721

mc->dh_bits = uret;

722

if(debug){

723

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

724

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

725

safe_string(gnutls_sec_param_get_name

726

(sec_param)),

727

mc->dh_bits);

728

}

729

} else {

730

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

731

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

732

safe_string(gnutls_sec_param_get_name

733

(sec_param)),

734

safer_gnutls_strerror(ret));

735

goto globalfail;

736

}

737

} else if(debug){

738

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

739

mc->dh_bits);

740

}

741

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

742

if(ret != GNUTLS_E_SUCCESS){

743

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

744

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

745

safer_gnutls_strerror(ret));

746

goto globalfail;

747

}

748

}

749

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

545

750

546

751

return 0;

547

752

548

753

globalfail:

549

754

550

gnutls_certificate_free_credentials(mc.cred);

551

gnutls_global_deinit();

552

gnutls_dh_params_deinit(mc.dh_params);

755

gnutls_certificate_free_credentials(mc->cred);

756

gnutls_dh_params_deinit(mc->dh_params);

553

757

return -1;

554

758

}

555

759

556

static int init_gnutls_session(gnutls_session_t *session){

760

__attribute__((nonnull, warn_unused_result))

761

static int init_gnutls_session(gnutls_session_t *session,

762

mandos_context *mc){

557

763

int ret;

558

764

/* GnuTLS session creation */

559

765

do {

571

777

{

572

778

const char *err;

573

779

do {

574

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

780

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

575

781

if(quit_now){

576

782

gnutls_deinit(*session);

577

783

return -1;

588

794

589

795

do {

590

796

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

591

mc.cred);

797

mc->cred);

592

798

if(quit_now){

593

799

gnutls_deinit(*session);

594

800

return -1;

604

810

/* ignore client certificate if any. */

605

811

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

606

812

607

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

608

609

813

return 0;

610

814

}

611

815

613

817

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

614

818

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

615

819

820

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

821

__attribute__((warn_unused_result))

822

int raise_privileges(void){

823

int old_errno = errno;

824

int ret = 0;

825

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

826

ret = errno;

827

}

828

errno = old_errno;

829

return ret;

830

}

831

832

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

833

__attribute__((warn_unused_result))

834

int raise_privileges_permanently(void){

835

int old_errno = errno;

836

int ret = raise_privileges();

837

if(ret != 0){

838

errno = old_errno;

839

return ret;

840

}

841

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

842

ret = errno;

843

}

844

errno = old_errno;

845

return ret;

846

}

847

848

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

849

__attribute__((warn_unused_result))

850

int lower_privileges(void){

851

int old_errno = errno;

852

int ret = 0;

853

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

854

ret = errno;

855

}

856

errno = old_errno;

857

return ret;

858

}

859

860

/* Lower privileges permanently */

861

__attribute__((warn_unused_result))

862

int lower_privileges_permanently(void){

863

int old_errno = errno;

864

int ret = 0;

865

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

866

ret = errno;

867

}

868

errno = old_errno;

869

return ret;

870

}

871

872

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

873

__attribute__((nonnull, warn_unused_result))

874

static bool add_delete_local_route(const bool add,

875

const char *address,

876

AvahiIfIndex if_index){

877

int ret;

878

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

879

char add_arg[] = "add";

880

char delete_arg[] = "delete";

881

char debug_flag[] = "--debug";

882

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

883

if(pluginhelperdir == NULL){

884

if(debug){

885

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

886

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

887

}

888

return false;

889

}

890

891

char interface[IF_NAMESIZE];

892

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

893

perror_plus("if_indextoname");

894

return false;

895

}

896

897

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

898

if(devnull == -1){

899

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

900

return false;

901

}

902

pid_t pid = fork();

903

if(pid == 0){

904

/* Child */

905

/* Raise privileges */

906

errno = raise_privileges_permanently();

907

if(errno != 0){

908

perror_plus("Failed to raise privileges");

909

/* _exit(EX_NOPERM); */

910

} else {

911

/* Set group */

912

errno = 0;

913

ret = setgid(0);

914

if(ret == -1){

915

perror_plus("setgid");

916

_exit(EX_NOPERM);

917

}

918

/* Reset supplementary groups */

919

errno = 0;

920

ret = setgroups(0, NULL);

921

if(ret == -1){

922

perror_plus("setgroups");

923

_exit(EX_NOPERM);

924

}

925

}

926

ret = dup2(devnull, STDIN_FILENO);

927

if(ret == -1){

928

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

929

_exit(EX_OSERR);

930

}

931

ret = close(devnull);

932

if(ret == -1){

933

perror_plus("close");

934

_exit(EX_OSERR);

935

}

936

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

937

if(ret == -1){

938

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

939

_exit(EX_OSERR);

940

}

941

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

942

O_RDONLY

943

| O_DIRECTORY

944

| O_PATH

945

| O_CLOEXEC));

946

if(helperdir_fd == -1){

947

perror_plus("open");

948

_exit(EX_UNAVAILABLE);

949

}

950

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

951

helper, O_RDONLY));

952

if(helper_fd == -1){

953

perror_plus("openat");

954

close(helperdir_fd);

955

_exit(EX_UNAVAILABLE);

956

}

957

close(helperdir_fd);

958

#ifdef __GNUC__

959

#pragma GCC diagnostic push

960

#pragma GCC diagnostic ignored "-Wcast-qual"

961

#endif

962

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

963

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

964

interface, debug ? debug_flag : NULL, NULL },

965

environ) == -1){

966

#ifdef __GNUC__

967

#pragma GCC diagnostic pop

968

#endif

969

perror_plus("fexecve");

970

_exit(EXIT_FAILURE);

971

}

972

}

973

if(pid == -1){

974

perror_plus("fork");

975

return false;

976

}

977

int status;

978

pid_t pret = -1;

979

errno = 0;

980

do {

981

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

982

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

983

int errno_raising = 0;

984

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

985

errno_raising = errno;

986

perror_plus("Failed to raise privileges in order to"

987

" kill helper program");

988

}

989

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

990

perror_plus("kill");

991

}

992

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

993

perror_plus("Failed to lower privileges after killing"

994

" helper program");

995

}

996

return false;

997

}

998

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

999

if(pret == -1){

1000

perror_plus("waitpid");

1001

return false;

1002

}

1003

if(WIFEXITED(status)){

1004

if(WEXITSTATUS(status) != 0){

1005

fprintf_plus(stderr, "Error: iprouteadddel exited"

1006

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

1007

return false;

1008

}

1009

return true;

1010

}

1011

if(WIFSIGNALED(status)){

1012

fprintf_plus(stderr, "Error: iprouteadddel died by"

1013

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

1014

return false;

1015

}

1016

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

1017

return false;

1018

}

1019

1020

__attribute__((nonnull, warn_unused_result))

1021

static bool add_local_route(const char *address,

1022

AvahiIfIndex if_index){

1023

if(debug){

1024

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

1025

}

1026

return add_delete_local_route(true, address, if_index);

1027

}

1028

1029

__attribute__((nonnull, warn_unused_result))

1030

static bool delete_local_route(const char *address,

1031

AvahiIfIndex if_index){

1032

if(debug){

1033

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

1034

}

1035

return add_delete_local_route(false, address, if_index);

1036

}

1037

616

1038

/* Called when a Mandos server is found */

617

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

1039

__attribute__((nonnull, warn_unused_result))

1040

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

618

1041

AvahiIfIndex if_index,

619

int af){

1042

int af, mandos_context *mc){

620

1043

int ret, tcp_sd = -1;

621

1044

ssize_t sret;

622

union {

623

struct sockaddr_in in;

624

struct sockaddr_in6 in6;

625

} to;

1045

struct sockaddr_storage to;

626

1046

char *buffer = NULL;

627

1047

char *decrypted_buffer = NULL;

628

1048

size_t buffer_length = 0;

631

1051

int retval = -1;

632

1052

gnutls_session_t session;

633

1053

int pf; /* Protocol family */

1054

bool route_added = false;

634

1055

635

1056

errno = 0;

636

1057

652

1073

return -1;

653

1074

}

654

1075

655

ret = init_gnutls_session(&session);

1076

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

1077

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

1078

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

1079

bool match = false;

1080

{

1081

char *interface = NULL;

1082

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

1083

interface))){

1084

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

1085

match = true;

1086

break;

1087

}

1088

}

1089

}

1090

if(not match){

1091

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

1092

connect to the server */

1093

if(debug){

1094

char interface[IF_NAMESIZE];

1095

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

1096

perror_plus("if_indextoname");

1097

} else {

1098

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

1099

" \"%s\"\n",

1100

if_indextoname((unsigned int)if_index,

1101

interface));

1102

}

1103

}

1104

return -1;

1105

}

1106

}

1107

1108

ret = init_gnutls_session(&session, mc);

656

1109

if(ret != 0){

657

1110

return -1;

658

1111

}

659

1112

660

1113

if(debug){

661

1114

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

662

PRIu16 "\n", ip, port);

1115

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

663

1116

}

664

1117

665

tcp_sd = socket(pf, SOCK_STREAM, 0);

1118

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

666

1119

if(tcp_sd < 0){

667

1120

int e = errno;

668

1121

perror_plus("socket");

675

1128

goto mandos_end;

676

1129

}

677

1130

678

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

679

1131

if(af == AF_INET6){

680

to.in6.sin6_family = (sa_family_t)af;

681

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

1132

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

1133

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

1134

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

682

1135

} else { /* IPv4 */

683

to.in.sin_family = (sa_family_t)af;

684

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

1136

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

1137

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

1138

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

685

1139

}

686

1140

if(ret < 0 ){

687

1141

int e = errno;

696

1150

goto mandos_end;

697

1151

}

698

1152

if(af == AF_INET6){

699

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

700

-Wconversion and

701

-Wunreachable-code */

702

703

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

704

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

705

-Wunreachable-code*/

1153

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

1154

if(IN6_IS_ADDR_LINKLOCAL

1155

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

706

1156

if(if_index == AVAHI_IF_UNSPEC){

707

1157

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

708

1158

" incomplete without a network interface\n");

710

1160

goto mandos_end;

711

1161

}

712

1162

/* Set the network interface number as scope */

713

to.in6.sin6_scope_id = (uint32_t)if_index;

1163

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

714

1164

}

715

1165

} else {

716

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

717

-Wconversion and

718

-Wunreachable-code */

1166

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

719

1167

}

720

1168

721

1169

if(quit_now){

729

1177

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

730

1178

perror_plus("if_indextoname");

731

1179

} else {

732

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

733

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

1180

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

1181

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

734

1182

}

735

1183

} else {

736

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

737

ip, port);

1184

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

1185

ip, (uintmax_t)port);

738

1186

}

739

1187

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

740

1188

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

741

const char *pcret;

742

if(af == AF_INET6){

743

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

744

sizeof(addrstr));

745

} else {

746

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

747

sizeof(addrstr));

748

}

749

if(pcret == NULL){

750

perror_plus("inet_ntop");

751

} else {

752

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

753

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

754

}

755

}

756

}

757

758

if(quit_now){

759

errno = EINTR;

760

goto mandos_end;

761

}

762

763

if(af == AF_INET6){

764

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

765

} else {

766

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

767

}

768

if(ret < 0){

769

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

770

int e = errno;

771

perror_plus("connect");

772

errno = e;

773

}

774

goto mandos_end;

775

}

776

777

if(quit_now){

778

errno = EINTR;

779

goto mandos_end;

1189

if(af == AF_INET6){

1190

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

1191

sizeof(struct sockaddr_in6),

1192

addrstr, sizeof(addrstr), NULL, 0,

1193

NI_NUMERICHOST);

1194

} else {

1195

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

1196

sizeof(struct sockaddr_in),

1197

addrstr, sizeof(addrstr), NULL, 0,

1198

NI_NUMERICHOST);

1199

}

1200

if(ret == EAI_SYSTEM){

1201

perror_plus("getnameinfo");

1202

} else if(ret != 0) {

1203

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

1204

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

1205

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

1206

}

1207

}

1208

1209

if(quit_now){

1210

errno = EINTR;

1211

goto mandos_end;

1212

}

1213

1214

while(true){

1215

if(af == AF_INET6){

1216

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

1217

sizeof(struct sockaddr_in6));

1218

} else {

1219

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

1220

sizeof(struct sockaddr_in));

1221

}

1222

if(ret < 0){

1223

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

1224

and if_index != AVAHI_IF_UNSPEC

1225

and connect_to == NULL

1226

and not route_added and

1227

((af == AF_INET6 and not

1228

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1229

&to)->sin6_addr)))

1230

or (af == AF_INET and

1231

/* Not a a IPv4LL address */

1232

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

1233

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

1234

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

1235

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

1236

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

1237

connect to a Mandos server announced by Avahi on a server

1238

host with a global address. Work around this by retrying

1239

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

1240

1241

Avahi bug reference:

1242

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

1243

https://bugs.debian.org/587961

1244

*/

1245

if(debug){

1246

fprintf_plus(stderr, "Mandos server unreachable, trying"

1247

" direct route\n");

1248

}

1249

int e = errno;

1250

route_added = add_local_route(ip, if_index);

1251

if(route_added){

1252

continue;

1253

}

1254

errno = e;

1255

}

1256

if(errno != ECONNREFUSED or debug){

1257

int e = errno;

1258

perror_plus("connect");

1259

errno = e;

1260

}

1261

goto mandos_end;

1262

}

1263

1264

if(quit_now){

1265

errno = EINTR;

1266

goto mandos_end;

1267

}

1268

break;

780

1269

}

781

1270

782

1271

const char *out = mandos_protocol_version;

818

1307

goto mandos_end;

819

1308

}

820

1309

821

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

822

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1310

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

1311

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

1312

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

1313

gnutls_transport_set_ptr(session,

1314

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

823

1315

824

1316

if(quit_now){

825

1317

errno = EINTR;

930

1422

if(buffer_length > 0){

931

1423

ssize_t decrypted_buffer_size;

932

1424

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

933

&decrypted_buffer);

1425

&decrypted_buffer, mc);

934

1426

if(decrypted_buffer_size >= 0){

935

1427

1428

clearerr(stdout);

936

1429

written = 0;

937

1430

while(written < (size_t) decrypted_buffer_size){

938

1431

if(quit_now){

954

1447

}

955

1448

written += (size_t)ret;

956

1449

}

1450

ret = fflush(stdout);

1451

if(ret != 0){

1452

int e = errno;

1453

if(debug){

1454

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

1455

strerror(errno));

1456

}

1457

errno = e;

1458

goto mandos_end;

1459

}

957

1460

retval = 0;

958

1461

}

959

1462

}

962

1465

963

1466

mandos_end:

964

1467

{

1468

if(route_added){

1469

if(not delete_local_route(ip, if_index)){

1470

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

1471

" interface %d", ip, if_index);

1472

}

1473

}

965

1474

int e = errno;

966

1475

free(decrypted_buffer);

967

1476

free(buffer);

968

1477

if(tcp_sd >= 0){

969

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

1478

ret = close(tcp_sd);

970

1479

}

971

1480

if(ret == -1){

972

1481

if(e == 0){

984

1493

return retval;

985

1494

}

986

1495

1496

__attribute__((nonnull))

987

1497

static void resolve_callback(AvahiSServiceResolver *r,

988

1498

AvahiIfIndex interface,

989

1499

AvahiProtocol proto,

997

1507

AVAHI_GCC_UNUSED AvahiStringList *txt,

998

1508

AVAHI_GCC_UNUSED AvahiLookupResultFlags

999

1509

flags,

1000

AVAHI_GCC_UNUSED void* userdata){

1001

assert(r);

1510

void *mc){

1511

if(r == NULL){

1512

return;

1513

}

1002

1514

1003

1515

/* Called whenever a service has been resolved successfully or

1004

1516

timed out */

1005

1517

1006

1518

if(quit_now){

1519

avahi_s_service_resolver_free(r);

1007

1520

return;

1008

1521

}

1009

1522

1013

1526

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

1014

1527

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

1015

1528

domain,

1016

avahi_strerror(avahi_server_errno(mc.server)));

1529

avahi_strerror(avahi_server_errno

1530

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

1017

1531

break;

1018

1532

1019

1533

case AVAHI_RESOLVER_FOUND:

1025

1539

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

1026

1540

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

1027

1541

}

1028

int ret = start_mandos_communication(ip, port, interface,

1029

avahi_proto_to_af(proto));

1542

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

1543

interface,

1544

avahi_proto_to_af(proto),

1545

mc);

1030

1546

if(ret == 0){

1031

avahi_simple_poll_quit(mc.simple_poll);

1547

avahi_simple_poll_quit(simple_poll);

1032

1548

} else {

1033

ret = add_server(ip, port, interface,

1034

avahi_proto_to_af(proto));

1549

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

1550

avahi_proto_to_af(proto),

1551

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

1552

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

1553

" list\n", name);

1554

}

1035

1555

}

1036

1556

}

1037

1557

}

1047

1567

const char *domain,

1048

1568

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1049

1569

flags,

1050

AVAHI_GCC_UNUSED void* userdata){

1051

assert(b);

1570

void *mc){

1571

if(b == NULL){

1572

return;

1573

}

1052

1574

1053

1575

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

1054

1576

is removed from the LAN */

1062

1584

case AVAHI_BROWSER_FAILURE:

1063

1585

1064

1586

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

1065

avahi_strerror(avahi_server_errno(mc.server)));

1066

avahi_simple_poll_quit(mc.simple_poll);

1587

avahi_strerror(avahi_server_errno

1588

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

1589

avahi_simple_poll_quit(simple_poll);

1067

1590

return;

1068

1591

1069

1592

case AVAHI_BROWSER_NEW:

1072

1595

the callback function is called the Avahi server will free the

1073

1596

resolver for us. */

1074

1597

1075

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

1076

name, type, domain, protocol, 0,

1077

resolve_callback, NULL) == NULL)

1598

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

1599

interface, protocol, name, type,

1600

domain, protocol, 0,

1601

resolve_callback, mc) == NULL)

1078

1602

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

1079

1603

" %s\n", name,

1080

avahi_strerror(avahi_server_errno(mc.server)));

1604

avahi_strerror(avahi_server_errno

1605

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

1081

1606

break;

1082

1607

1083

1608

case AVAHI_BROWSER_REMOVE:

1102

1627

signal_received = sig;

1103

1628

int old_errno = errno;

1104

1629

/* set main loop to exit */

1105

if(mc.simple_poll != NULL){

1106

avahi_simple_poll_quit(mc.simple_poll);

1630

if(simple_poll != NULL){

1631

avahi_simple_poll_quit(simple_poll);

1107

1632

}

1108

1633

errno = old_errno;

1109

1634

}

1110

1635

1636

__attribute__((nonnull, warn_unused_result))

1111

1637

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

1112

1638

int ret;

1639

int old_errno;

1113

1640

1114

1641

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

1115

1642

if(s < 0){

1643

old_errno = errno;

1116

1644

perror_plus("socket");

1645

errno = old_errno;

1117

1646

return false;

1118

1647

}

1119

strcpy(ifr->ifr_name, ifname);

1648

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

1649

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

1120

1650

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1121

1651

if(ret == -1){

1122

1652

if(debug){

1653

old_errno = errno;

1123

1654

perror_plus("ioctl SIOCGIFFLAGS");

1655

errno = old_errno;

1124

1656

}

1125

1657

return false;

1126

1658

}

1127

1659

return true;

1128

1660

}

1129

1661

1662

__attribute__((nonnull, warn_unused_result))

1130

1663

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

1131

1664

1132

1665

/* Reject the loopback device */

1174

1707

* corresponds to an acceptable network device.

1175

1708

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

1176

1709

*/

1710

__attribute__((nonnull, warn_unused_result))

1177

1711

int good_interface(const struct dirent *if_entry){

1178

1712

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

1179

1713

return 0;

1195

1729

}

1196

1730

1197

1731

/*

1198

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

1199

* corresponds to an acceptable network device which is up.

1200

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

1201

*/

1202

int up_interface(const struct dirent *if_entry){

1203

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

1204

return 0;

1205

}

1206

1207

struct ifreq ifr;

1208

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

1209

if(debug){

1210

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

1211

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

1212

}

1213

return 0;

1214

}

1215

1216

/* Reject down interfaces */

1217

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

1218

if(debug){

1219

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

1220

if_entry->d_name);

1221

}

1222

return 0;

1223

}

1224

1225

/* Reject non-running interfaces */

1226

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

1227

if(debug){

1228

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

1229

if_entry->d_name);

1230

}

1231

return 0;

1232

}

1233

1234

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

1235

return 0;

1236

}

1237

return 1;

1238

}

1239

1732

* This function determines if a network interface is up.

1733

*/

1734

__attribute__((nonnull, warn_unused_result))

1735

bool interface_is_up(const char *interface){

1736

struct ifreq ifr;

1737

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

1738

if(debug){

1739

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

1740

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

1741

}

1742

return false;

1743

}

1744

1745

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

1746

}

1747

1748

/*

1749

* This function determines if a network interface is running

1750

*/

1751

__attribute__((nonnull, warn_unused_result))

1752

bool interface_is_running(const char *interface){

1753

struct ifreq ifr;

1754

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

1755

if(debug){

1756

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

1757

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

1758

}

1759

return false;

1760

}

1761

1762

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

1763

}

1764

1765

__attribute__((nonnull, pure, warn_unused_result))

1240

1766

int notdotentries(const struct dirent *direntry){

1241

1767

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

1242

1768

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

1249

1775

}

1250

1776

1251

1777

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

1778

__attribute__((nonnull, warn_unused_result))

1252

1779

int runnable_hook(const struct dirent *direntry){

1253

1780

int ret;

1254

1781

size_t sret;

1262

1789

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

1263

1790

"abcdefghijklmnopqrstuvwxyz"

1264

1791

"0123456789"

1265

"_-");

1792

"_.-");

1266

1793

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

1267

1794

/* Contains non-allowed characters */

1268

1795

if(debug){

1272

1799

return 0;

1273

1800

}

1274

1801

1275

char *fullname = NULL;

1276

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

1277

if(ret < 0){

1278

perror_plus("asprintf");

1279

return 0;

1280

}

1281

1282

ret = stat(fullname, &st);

1802

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

1283

1803

if(ret == -1){

1284

1804

if(debug){

1285

1805

perror_plus("Could not stat hook");

1309

1829

return 1;

1310

1830

}

1311

1831

1312

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1832

__attribute__((nonnull, warn_unused_result))

1833

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1834

mandos_context *mc){

1313

1835

int ret;

1314

1836

struct timespec now;

1315

1837

struct timespec waited_time;

1316

1838

intmax_t block_time;

1317

1839

1318

1840

while(true){

1319

if(mc.current_server == NULL){

1320

if (debug){

1841

if(mc->current_server == NULL){

1842

if(debug){

1321

1843

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

1322

1844

" No timeout!\n");

1323

1845

}

1324

1846

ret = avahi_simple_poll_iterate(s, -1);

1325

1847

} else {

1326

if (debug){

1848

if(debug){

1327

1849

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

1328

1850

" it, or wait\n");

1329

1851

}

1336

1858

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

1337

1859

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

1338

1860

waited_time.tv_sec = (now.tv_sec

1339

- mc.current_server->last_seen.tv_sec);

1861

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

1340

1862

waited_time.tv_nsec = (now.tv_nsec

1341

- mc.current_server->last_seen.tv_nsec);

1863

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

1342

1864

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

1343

1865

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

1344

1866

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

1346

1868

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

1347

1869

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

1348

1870

1349

if (debug){

1871

if(debug){

1350

1872

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

1351

1873

block_time);

1352

1874

}

1353

1875

1354

1876

if(block_time <= 0){

1355

ret = start_mandos_communication(mc.current_server->ip,

1356

mc.current_server->port,

1357

mc.current_server->if_index,

1358

mc.current_server->af);

1877

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

1878

mc->current_server->port,

1879

mc->current_server->if_index,

1880

mc->current_server->af, mc);

1359

1881

if(ret == 0){

1360

avahi_simple_poll_quit(mc.simple_poll);

1882

avahi_simple_poll_quit(s);

1361

1883

return 0;

1362

1884

}

1363

1885

ret = clock_gettime(CLOCK_MONOTONIC,

1364

&mc.current_server->last_seen);

1886

&mc->current_server->last_seen);

1365

1887

if(ret == -1){

1366

1888

perror_plus("clock_gettime");

1367

1889

return -1;

1368

1890

}

1369

mc.current_server = mc.current_server->next;

1891

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

1370

1892

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

1371

1893

servers, but don't block */

1372

1894

}

1374

1896

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

1375

1897

}

1376

1898

if(ret != 0){

1377

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

1899

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

1378

1900

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

1379

1901

}

1380

1902

}

1381

1903

}

1382

1904

}

1383

1905

1384

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

1906

__attribute__((nonnull))

1907

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

1385

1908

const float delay){

1386

struct dirent **direntries;

1387

struct dirent *direntry;

1388

int ret;

1389

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

1390

alphasort);

1909

struct dirent **direntries = NULL;

1910

if(hookdir_fd == -1){

1911

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1912

| O_CLOEXEC);

1913

if(hookdir_fd == -1){

1914

if(errno == ENOENT){

1915

if(debug){

1916

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

1917

" found\n", hookdir);

1918

}

1919

} else {

1920

perror_plus("open");

1921

}

1922

return;

1923

}

1924

}

1925

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

1926

runnable_hook, alphasort);

1391

1927

if(numhooks == -1){

1392

1928

perror_plus("scandir");

1393

} else {

1394

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

1395

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

1396

direntry = direntries[i];

1397

char *fullname = NULL;

1398

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

1399

if(ret < 0){

1929

return;

1930

}

1931

struct dirent *direntry;

1932

int ret;

1933

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

1934

if(devnull == -1){

1935

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

1936

return;

1937

}

1938

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

1939

direntry = direntries[i];

1940

if(debug){

1941

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

1942

direntry->d_name);

1943

}

1944

pid_t hook_pid = fork();

1945

if(hook_pid == 0){

1946

/* Child */

1947

/* Raise privileges */

1948

errno = raise_privileges_permanently();

1949

if(errno != 0){

1950

perror_plus("Failed to raise privileges");

1951

_exit(EX_NOPERM);

1952

}

1953

/* Set group */

1954

errno = 0;

1955

ret = setgid(0);

1956

if(ret == -1){

1957

perror_plus("setgid");

1958

_exit(EX_NOPERM);

1959

}

1960

/* Reset supplementary groups */

1961

errno = 0;

1962

ret = setgroups(0, NULL);

1963

if(ret == -1){

1964

perror_plus("setgroups");

1965

_exit(EX_NOPERM);

1966

}

1967

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

1968

if(ret == -1){

1969

perror_plus("setenv");

1970

_exit(EX_OSERR);

1971

}

1972

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

1973

if(ret == -1){

1974

perror_plus("setenv");

1975

_exit(EX_OSERR);

1976

}

1977

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

1978

if(ret == -1){

1979

perror_plus("setenv");

1980

_exit(EX_OSERR);

1981

}

1982

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

1983

if(ret == -1){

1984

perror_plus("setenv");

1985

_exit(EX_OSERR);

1986

}

1987

char *delaystring;

1988

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

1989

if(ret == -1){

1400

1990

perror_plus("asprintf");

1401

continue;

1402

}

1403

if(debug){

1404

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

1405

direntry->d_name);

1406

}

1407

pid_t hook_pid = fork();

1408

if(hook_pid == 0){

1409

/* Child */

1410

/* Raise privileges */

1411

errno = 0;

1412

ret = seteuid(0);

1413

if(ret == -1){

1414

perror_plus("seteuid");

1415

}

1416

/* Raise privileges even more */

1417

errno = 0;

1418

ret = setuid(0);

1419

if(ret == -1){

1420

perror_plus("setuid");

1421

}

1422

/* Set group */

1423

errno = 0;

1424

ret = setgid(0);

1425

if(ret == -1){

1426

perror_plus("setgid");

1427

}

1428

/* Reset supplementary groups */

1429

errno = 0;

1430

ret = setgroups(0, NULL);

1431

if(ret == -1){

1432

perror_plus("setgroups");

1433

}

1434

fprintf_plus(stderr, "Child: getuid() = %d\n", getuid());

1435

fprintf_plus(stderr, "Child: geteuid() = %d\n", geteuid());

1436

dup2(devnull, STDIN_FILENO);

1437

close(devnull);

1438

dup2(STDERR_FILENO, STDOUT_FILENO);

1439

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

1440

if(ret == -1){

1441

perror_plus("setenv");

1442

_exit(EX_OSERR);

1443

}

1444

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

1445

if(ret == -1){

1446

perror_plus("setenv");

1447

_exit(EX_OSERR);

1448

}

1449

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

1450

if(ret == -1){

1451

perror_plus("setenv");

1452

_exit(EX_OSERR);

1453

}

1454

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

1455

if(ret == -1){

1456

perror_plus("setenv");

1457

_exit(EX_OSERR);

1458

}

1459

char *delaystring;

1460

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

1461

if(ret == -1){

1462

perror_plus("asprintf");

1463

_exit(EX_OSERR);

1464

}

1465

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

1466

if(ret == -1){

1467

free(delaystring);

1468

perror_plus("setenv");

1469

_exit(EX_OSERR);

1470

}

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1471

1995

free(delaystring);

1472

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

1473

perror_plus("execl");

1474

} else {

1475

int status;

1476

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

1477

perror_plus("waitpid");

1478

free(fullname);

1479

continue;

1480

}

1481

if(WIFEXITED(status)){

1482

if(WEXITSTATUS(status) != 0){

1483

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

1484

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

1485

WEXITSTATUS(status));

1486

free(fullname);

1487

continue;

1488

}

1489

} else if(WIFSIGNALED(status)){

1490

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

1491

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

1492

WTERMSIG(status));

1493

free(fullname);

1494

continue;

1495

} else {

1496

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

1497

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

1498

free(fullname);

1499

continue;

1500

}

1501

}

1502

free(fullname);

1503

if(debug){

1504

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

1505

direntry->d_name);

1506

}

1507

}

1508

close(devnull);

1509

}

1510

return true;

1996

perror_plus("setenv");

1997

_exit(EX_OSERR);

1998

}

1999

free(delaystring);

2000

if(connect_to != NULL){

2001

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

2002

if(ret == -1){

2003

perror_plus("setenv");

2004

_exit(EX_OSERR);

2005

}

2006

}

2007

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

2008

direntry->d_name,

2009

O_RDONLY));

2010

if(hook_fd == -1){

2011

perror_plus("openat");

2012

_exit(EXIT_FAILURE);

2013

}

2014

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

2015

perror_plus("close");

2016

_exit(EXIT_FAILURE);

2017

}

2018

ret = dup2(devnull, STDIN_FILENO);

2019

if(ret == -1){

2020

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

2021

_exit(EX_OSERR);

2022

}

2023

ret = close(devnull);

2024

if(ret == -1){

2025

perror_plus("close");

2026

_exit(EX_OSERR);

2027

}

2028

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2029

if(ret == -1){

2030

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

2031

_exit(EX_OSERR);

2032

}

2033

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

2034

environ) == -1){

2035

perror_plus("fexecve");

2036

_exit(EXIT_FAILURE);

2037

}

2038

} else {

2039

if(hook_pid == -1){

2040

perror_plus("fork");

2041

free(direntry);

2042

continue;

2043

}

2044

int status;

2045

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

2046

perror_plus("waitpid");

2047

free(direntry);

2048

continue;

2049

}

2050

if(WIFEXITED(status)){

2051

if(WEXITSTATUS(status) != 0){

2052

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

2053

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

2054

WEXITSTATUS(status));

2055

free(direntry);

2056

continue;

2057

}

2058

} else if(WIFSIGNALED(status)){

2059

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

2060

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

2061

WTERMSIG(status));

2062

free(direntry);

2063

continue;

2064

} else {

2065

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

2066

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

2067

free(direntry);

2068

continue;

2069

}

2070

}

2071

if(debug){

2072

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

2073

direntry->d_name);

2074

}

2075

free(direntry);

2076

}

2077

free(direntries);

2078

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

2079

perror_plus("close");

2080

} else {

2081

hookdir_fd = -1;

2082

}

2083

close(devnull);

2084

}

2085

2086

__attribute__((nonnull, warn_unused_result))

2087

int bring_up_interface(const char *const interface,

2088

const float delay){

2089

int old_errno = errno;

2090

int ret;

2091

struct ifreq network;

2092

unsigned int if_index = if_nametoindex(interface);

2093

if(if_index == 0){

2094

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

2095

errno = old_errno;

2096

return ENXIO;

2097

}

2098

2099

if(quit_now){

2100

errno = old_errno;

2101

return EINTR;

2102

}

2103

2104

if(not interface_is_up(interface)){

2105

int ret_errno = 0;

2106

int ioctl_errno = 0;

2107

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

2108

ret_errno = errno;

2109

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

2110

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

2111

errno = old_errno;

2112

return ret_errno;

2113

}

2114

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

2115

2116

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

2117

if(sd == -1){

2118

ret_errno = errno;

2119

perror_plus("socket");

2120

errno = old_errno;

2121

return ret_errno;

2122

}

2123

2124

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

2129

errno = old_errno;

2130

return EINTR;

2131

}

2132

2133

if(debug){

2134

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

2135

interface);

2136

}

2137

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

2144

2145

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

2157

}

2158

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

2161

#ifdef __linux__

2162

if(restore_loglevel){

2163

ret_linux = klogctl(7, NULL, 0);

2164

if(ret_linux == -1){

2165

perror_plus("klogctl");

2166

}

2167

}

2168

#endif /* __linux__ */

2169

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

2179

2180

/* Close the socket */

2181

ret = close(sd);

2182

if(ret == -1){

2183

perror_plus("close");

2184

}

2185

2186

if(ret_setflags == -1){

2187

errno = ioctl_errno;

2188

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

errno = old_errno;

2190

return ioctl_errno;

2191

}

2192

} else if(debug){

2193

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

2194

interface);

2195

}

2196

2197

/* Sleep checking until interface is running.

2198

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

2199

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

2200

if(interface_is_running(interface)){

2201

break;

2202

}

2203

struct timespec sleeptime = { .tv_nsec = 250000000 };

2204

ret = nanosleep(&sleeptime, NULL);

2205

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

2206

perror_plus("nanosleep");

2207

}

2208

}

2209

2210

errno = old_errno;

2211

return 0;

2212

}

2213

2214

__attribute__((nonnull, warn_unused_result))

2215

int take_down_interface(const char *const interface){

2216

int old_errno = errno;

2217

struct ifreq network;

2218

unsigned int if_index = if_nametoindex(interface);

2219

if(if_index == 0){

2220

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

2221

errno = old_errno;

2222

return ENXIO;

2223

}

2224

if(interface_is_up(interface)){

2225

int ret_errno = 0;

2226

int ioctl_errno = 0;

2227

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

2228

ret_errno = errno;

2229

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

2230

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

2231

errno = old_errno;

2232

return ret_errno;

2233

}

2234

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

2235

2236

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

2237

if(sd == -1){

2238

ret_errno = errno;

2239

perror_plus("socket");

2240

errno = old_errno;

2241

return ret_errno;

2242

}

2243

2244

if(debug){

2245

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

2246

interface);

2247

}

2248

2249

/* Raise privileges */

2250

ret_errno = raise_privileges();

2251

if(ret_errno != 0){

2252

errno = ret_errno;

2253

perror_plus("Failed to raise privileges");

2254

}

2255

2256

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

2257

ioctl_errno = errno;

2258

2259

/* If raise_privileges() succeeded above */

2260

if(ret_errno == 0){

2261

/* Lower privileges */

2262

ret_errno = lower_privileges();

2263

if(ret_errno != 0){

2264

errno = ret_errno;

2265

perror_plus("Failed to lower privileges");

2266

}

2267

}

2268

2269

/* Close the socket */

2270

int ret = close(sd);

2271

if(ret == -1){

2272

perror_plus("close");

2273

}

2274

2275

if(ret_setflags == -1){

2276

errno = ioctl_errno;

2277

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2278

errno = old_errno;

2279

return ioctl_errno;

2280

}

2281

} else if(debug){

2282

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

2283

interface);

2284

}

2285

2286

errno = old_errno;

2287

return 0;

1511

2288

}

1512

2289

1513

2290

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

2291

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

2292

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

2293

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

2294

.current_server = NULL, .interfaces = NULL,

2295

.interfaces_size = 0 };

1514

2296

AvahiSServiceBrowser *sb = NULL;

1515

int error;

2297

error_t ret_errno;

1516

2298

int ret;

1517

2299

intmax_t tmpmax;

1518

2300

char *tmp;

1519

2301

int exitcode = EXIT_SUCCESS;

1520

const char *interface = "";

1521

struct ifreq network;

1522

int sd = -1;

1523

bool take_down_interface = false;

1524

uid_t uid;

1525

gid_t gid;

1526

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

1527

bool tempdir_created = false;

2302

char *interfaces_to_take_down = NULL;

2303

size_t interfaces_to_take_down_size = 0;

2304

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

2305

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

2306

char *tempdir = NULL;

1528

2307

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1529

2308

const char *seckey = PATHDIR "/" SECKEY;

1530

2309

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

2311

char *interfaces_hooks = NULL;

1531

2312

1532

2313

bool gnutls_initialized = false;

1533

2314

bool gpgme_initialized = false;

1585

2366

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

1586

2367

" Diffie-Hellman key exchange",

1587

2368

.group = 2 },

2369

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

2370

.arg = "FILE",

2371

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

2372

" for the Diffie-Hellman key exchange",

2373

.group = 2 },

1588

2374

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

1589

2375

.arg = "STRING",

1590

2376

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

1595

2381

.group = 2 },

1596

2382

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

1597

2383

.arg = "SECONDS",

1598

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

2384

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

1599

2385

.group = 2 },

1600

2386

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

1601

2387

.arg = "DIR",

1624

2410

connect_to = arg;

1625

2411

break;

1626

2412

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

1627

interface = arg;

2413

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

2414

arg, (int)',');

2415

if(ret_errno != 0){

2416

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

2417

}

1628

2418

break;

1629

2419

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

1630

2420

seckey = arg;

1641

2431

}

1642

2432

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

1643

2433

break;

2434

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

2435

dh_params_file = arg;

2436

break;

1644

2437

case 130: /* --priority */

1645

2438

mc.priority = arg;

1646

2439

break;

1673

2466

argp_state_help(state, state->out_stream,

1674

2467

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1675

2468

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

1676

fprintf_plus(state->out_stream,

1677

"Mandos plugin mandos-client: ");

1678

2469

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

1679

2470

exit(argp_err_exit_status);

1680

2471

break;

1688

2479

.args_doc = "",

1689

2480

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

1690

2481

" passwords from a Mandos server" };

1691

ret = argp_parse(&argp, argc, argv,

1692

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1693

switch(ret){

2482

ret_errno = argp_parse(&argp, argc, argv,

2483

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2484

switch(ret_errno){

1694

2485

case 0:

1695

2486

break;

1696

2487

case ENOMEM:

1697

2488

default:

1698

errno = ret;

2489

errno = ret_errno;

1699

2490

perror_plus("argp_parse");

1700

2491

exitcode = EX_OSERR;

1701

2492

goto end;

1704

2495

goto end;

1705

2496

}

1706

2497

}

1707

2498

1708

2499

{

1709

2500

/* Work around Debian bug #633582:

1710

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

2501

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

1711

2502

1712

/* Re-raise priviliges */

1713

errno = 0;

1714

ret = seteuid(0);

1715

if(ret == -1){

1716

perror_plus("seteuid");

2503

/* Re-raise privileges */

2504

ret = raise_privileges();

2505

if(ret != 0){

2506

errno = ret;

2507

perror_plus("Failed to raise privileges");

1717

2508

} else {

1718

2509

struct stat st;

1719

2510

1734

2525

}

1735

2526

}

1736

2527

}

1737

TEMP_FAILURE_RETRY(close(seckey_fd));

2528

close(seckey_fd);

1738

2529

}

1739

2530

}

1740

2531

1741

2532

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

1742

2533

int pubkey_fd = open(pubkey, O_RDONLY);

1743

2534

if(pubkey_fd == -1){

1755

2546

}

1756

2547

}

1757

2548

}

1758

TEMP_FAILURE_RETRY(close(pubkey_fd));

1759

}

1760

}

1761

2549

close(pubkey_fd);

2550

}

2551

}

2552

2553

if(dh_params_file != NULL

2554

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

2555

int dhparams_fd = open(dh_params_file, O_RDONLY);

2556

if(dhparams_fd == -1){

2557

perror_plus("open");

2558

} else {

2559

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

2560

if(ret == -1){

2561

perror_plus("fstat");

2562

} else {

2563

if(S_ISREG(st.st_mode)

2564

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

2565

ret = fchown(dhparams_fd, uid, gid);

2566

if(ret == -1){

2567

perror_plus("fchown");

2568

}

2569

}

2570

}

2571

close(dhparams_fd);

2572

}

2573

}

2574

1762

2575

/* Lower privileges */

1763

errno = 0;

1764

ret = seteuid(uid);

1765

if(ret == -1){

1766

perror_plus("seteuid");

2576

ret = lower_privileges();

2577

if(ret != 0){

2578

errno = ret;

2579

perror_plus("Failed to lower privileges");

2580

}

2581

}

2582

}

2583

2584

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

2585

{

2586

char *interface = NULL;

2587

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

2588

interface))){

2589

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

2590

and if_nametoindex(interface) == 0){

2591

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

2592

fprintf_plus(stderr, "Not using nonexisting interface"

2593

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

2594

}

2595

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

2596

interface = NULL;

1767

2597

}

1768

2598

}

1769

2599

}

1770

2600

1771

2601

/* Run network hooks */

1772

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

1773

goto end;

2602

{

2603

if(mc.interfaces != NULL){

2604

interfaces_hooks = malloc(mc.interfaces_size);

2605

if(interfaces_hooks == NULL){

2606

perror_plus("malloc");

2607

goto end;

2608

}

2609

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

2610

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

2611

}

2612

run_network_hooks("start", interfaces_hooks != NULL ?

2613

interfaces_hooks : "", delay);

1774

2614

}

1775

2615

1776

2616

if(not debug){

1777

2617

avahi_set_log_function(empty_log);

1778

2618

}

1779

2619

1780

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

1781

struct dirent **direntries;

1782

/* First look for interfaces that are up */

1783

ret = scandir(sys_class_net, &direntries, up_interface,

1784

alphasort);

1785

if(ret == 0){

1786

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

1787

free(direntries);

1788

ret = scandir(sys_class_net, &direntries, good_interface,

1789

alphasort);

1790

}

1791

if(ret >= 1){

1792

/* Pick the first interface returned */

1793

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

1794

if(debug){

1795

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

1796

}

1797

if(interface == NULL){

1798

perror_plus("malloc");

1799

free(direntries);

1800

exitcode = EXIT_FAILURE;

1801

goto end;

1802

}

1803

free(direntries);

1804

} else {

1805

free(direntries);

1806

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

1807

exitcode = EXIT_FAILURE;

1808

goto end;

1809

}

1810

}

1811

1812

2620

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

1813

2621

from the signal handler */

1814

2622

/* Initialize the pseudo-RNG for Avahi */

1815

2623

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

1816

mc.simple_poll = avahi_simple_poll_new();

1817

if(mc.simple_poll == NULL){

2624

simple_poll = avahi_simple_poll_new();

2625

if(simple_poll == NULL){

1818

2626

fprintf_plus(stderr,

1819

2627

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

1820

2628

exitcode = EX_UNAVAILABLE;

1884

2692

}

1885

2693

}

1886

2694

1887

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

1888

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

1889

if_index = (AvahiIfIndex) if_nametoindex(interface);

1890

if(if_index == 0){

1891

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

1892

exitcode = EX_UNAVAILABLE;

1893

goto end;

1894

}

1895

1896

if(quit_now){

1897

goto end;

1898

}

1899

1900

/* Re-raise priviliges */

1901

errno = 0;

1902

ret = seteuid(0);

1903

if(ret == -1){

1904

perror_plus("seteuid");

1905

}

1906

1907

#ifdef __linux__

1908

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1909

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

1910

ret = klogctl(8, NULL, 5);

1911

bool restore_loglevel = true;

1912

if(ret == -1){

1913

restore_loglevel = false;

1914

perror_plus("klogctl");

1915

}

1916

#endif /* __linux__ */

1917

1918

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1919

if(sd < 0){

1920

perror_plus("socket");

1921

exitcode = EX_OSERR;

1922

#ifdef __linux__

1923

if(restore_loglevel){

1924

ret = klogctl(7, NULL, 0);

1925

if(ret == -1){

1926

perror_plus("klogctl");

1927

}

1928

}

1929

#endif /* __linux__ */

1930

/* Lower privileges */

1931

errno = 0;

1932

ret = seteuid(uid);

1933

if(ret == -1){

1934

perror_plus("seteuid");

1935

}

1936

goto end;

1937

}

1938

strcpy(network.ifr_name, interface);

1939

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

1940

if(ret == -1){

1941

perror_plus("ioctl SIOCGIFFLAGS");

1942

#ifdef __linux__

1943

if(restore_loglevel){

1944

ret = klogctl(7, NULL, 0);

1945

if(ret == -1){

1946

perror_plus("klogctl");

1947

}

1948

}

1949

#endif /* __linux__ */

1950

exitcode = EX_OSERR;

1951

/* Lower privileges */

1952

errno = 0;

1953

ret = seteuid(uid);

1954

if(ret == -1){

1955

perror_plus("seteuid");

1956

}

1957

goto end;

1958

}

1959

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

1960

network.ifr_flags |= IFF_UP;

1961

take_down_interface = true;

1962

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

1963

if(ret == -1){

1964

take_down_interface = false;

1965

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1966

exitcode = EX_OSERR;

1967

#ifdef __linux__

1968

if(restore_loglevel){

1969

ret = klogctl(7, NULL, 0);

1970

if(ret == -1){

1971

perror_plus("klogctl");

2695

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

2696

if(mc.interfaces == NULL){

2697

struct dirent **direntries = NULL;

2698

/* Look for any good interfaces */

2699

ret = scandir(sys_class_net, &direntries, good_interface,

2700

alphasort);

2701

if(ret >= 1){

2702

/* Add all found interfaces to interfaces list */

2703

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

2704

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

2705

direntries[i]->d_name);

2706

if(ret_errno != 0){

2707

errno = ret_errno;

2708

perror_plus("argz_add");

2709

free(direntries[i]);

2710

continue;

2711

}

2712

if(debug){

2713

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

2714

direntries[i]->d_name);

2715

}

2716

free(direntries[i]);

2717

}

2718

free(direntries);

2719

} else {

2720

if(ret == 0){

2721

free(direntries);

2722

}

2723

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

2724

exitcode = EXIT_FAILURE;

2725

goto end;

2726

}

2727

}

2728

2729

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

2730

{

2731

char *interface = NULL;

2732

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

2733

interface))){

2734

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

2735

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

2736

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

2737

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

2738

interface);

2739

interface = NULL;

2740

while((interface = argz_next(mc.interfaces,

2741

mc.interfaces_size, interface))){

2742

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

2743

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

2744

interface);

2745

interface = NULL;

1972

2746

}

1973

2747

}

1974

#endif /* __linux__ */

1975

/* Lower privileges */

1976

errno = 0;

1977

ret = seteuid(uid);

1978

if(ret == -1){

1979

perror_plus("seteuid");

1980

}

1981

goto end;

1982

}

1983

}

1984

/* Sleep checking until interface is running.

1985

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

1986

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

1987

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

1988

if(ret == -1){

1989

perror_plus("ioctl SIOCGIFFLAGS");

1990

} else if(network.ifr_flags & IFF_RUNNING){

1991

2748

break;

1992

2749

}

1993

struct timespec sleeptime = { .tv_nsec = 250000000 };

1994

ret = nanosleep(&sleeptime, NULL);

1995

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

1996

perror_plus("nanosleep");

1997

}

1998

}

1999

if(not take_down_interface){

2000

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

2001

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

2002

if(ret == -1){

2003

perror_plus("close");

2004

}

2005

}

2006

#ifdef __linux__

2007

if(restore_loglevel){

2008

/* Restores kernel loglevel to default */

2009

ret = klogctl(7, NULL, 0);

2010

if(ret == -1){

2011

perror_plus("klogctl");

2012

}

2013

}

2014

#endif /* __linux__ */

2015

/* Lower privileges */

2016

errno = 0;

2017

/* Lower privileges */

2018

ret = seteuid(uid);

2019

if(ret == -1){

2020

perror_plus("seteuid");

2021

}

2750

bool interface_was_up = interface_is_up(interface);

2751

errno = bring_up_interface(interface, delay);

2752

if(not interface_was_up){

2753

if(errno != 0){

2754

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

2755

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

2756

} else {

2757

errno = argz_add(&interfaces_to_take_down,

2758

&interfaces_to_take_down_size,

2759

interface);

2760

if(errno != 0){

2761

perror_plus("argz_add");

2762

}

2763

}

2764

}

2765

}

2766

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

2767

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

2768

}

2769

}

2770

2771

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

2772

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

2773

if(debug){

2774

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

2775

mc.interfaces);

2776

}

2777

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

2022

2778

}

2023

2779

2024

2780

if(quit_now){

2025

2781

goto end;

2026

2782

}

2027

2783

2028

ret = init_gnutls_global(pubkey, seckey);

2784

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

2029

2785

if(ret == -1){

2030

2786

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

2031

2787

exitcode = EX_UNAVAILABLE;

2038

2794

goto end;

2039

2795

}

2040

2796

2041

if(mkdtemp(tempdir) == NULL){

2797

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

2798

tempdir = mkdtemp(run_tempdir);

2799

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

2800

if(debug){

2801

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

2802

run_tempdir, old_tempdir);

2803

}

2804

tempdir = mkdtemp(old_tempdir);

2805

}

2806

if(tempdir == NULL){

2042

2807

perror_plus("mkdtemp");

2043

2808

goto end;

2044

2809

}

2045

tempdir_created = true;

2046

2810

2047

2811

if(quit_now){

2048

2812

goto end;

2049

2813

}

2050

2814

2051

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

2815

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

2052

2816

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

2053

2817

exitcode = EX_UNAVAILABLE;

2054

2818

goto end;

2064

2828

/* Connect directly, do not use Zeroconf */

2065

2829

/* (Mainly meant for debugging) */

2066

2830

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

2831

2067

2832

if(address == NULL){

2068

2833

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

2069

2834

exitcode = EX_USAGE;

2074

2839

goto end;

2075

2840

}

2076

2841

2077

uint16_t port;

2842

in_port_t port;

2078

2843

errno = 0;

2079

2844

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

2080

2845

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

2081

or tmpmax != (uint16_t)tmpmax){

2846

or tmpmax != (in_port_t)tmpmax){

2082

2847

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

2083

2848

exitcode = EX_USAGE;

2084

2849

goto end;

2085

2850

}

2086

2851

2087

2852

if(quit_now){

2088

2853

goto end;

2089

2854

}

2090

2855

2091

port = (uint16_t)tmpmax;

2856

port = (in_port_t)tmpmax;

2092

2857

*address = '\0';

2093

2858

/* Colon in address indicates IPv6 */

2094

2859

int af;

2110

2875

}

2111

2876

2112

2877

while(not quit_now){

2113

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

2878

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

2879

&mc);

2114

2880

if(quit_now or ret == 0){

2115

2881

break;

2116

2882

}

2118

2884

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

2119

2885

(int)retry_interval);

2120

2886

}

2121

sleep((int)retry_interval);

2887

sleep((unsigned int)retry_interval);

2122

2888

}

2123

2889

2124

if (not quit_now){

2890

if(not quit_now){

2125

2891

exitcode = EXIT_SUCCESS;

2126

2892

}

2127

2893

2142

2908

config.publish_domain = 0;

2143

2909

2144

2910

/* Allocate a new server */

2145

mc.server = avahi_server_new(avahi_simple_poll_get

2146

(mc.simple_poll), &config, NULL,

2147

NULL, &error);

2911

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2912

&config, NULL, NULL, &ret);

2148

2913

2149

2914

/* Free the Avahi configuration data */

2150

2915

avahi_server_config_free(&config);

2153

2918

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

2154

2919

if(mc.server == NULL){

2155

2920

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

2156

avahi_strerror(error));

2921

avahi_strerror(ret));

2157

2922

exitcode = EX_UNAVAILABLE;

2158

2923

goto end;

2159

2924

}

2165

2930

/* Create the Avahi service browser */

2166

2931

sb = avahi_s_service_browser_new(mc.server, if_index,

2167

2932

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2168

NULL, 0, browse_callback, NULL);

2933

NULL, 0, browse_callback,

2934

(void *)&mc);

2169

2935

if(sb == NULL){

2170

2936

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

2171

2937

avahi_strerror(avahi_server_errno(mc.server)));

2182

2948

if(debug){

2183

2949

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

2184

2950

}

2185

2186

ret = avahi_loop_with_timeout(mc.simple_poll,

2187

(int)(retry_interval * 1000));

2951

2952

ret = avahi_loop_with_timeout(simple_poll,

2953

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

2188

2954

if(debug){

2189

2955

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

2190

2956

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

2193

2959

end:

2194

2960

2195

2961

if(debug){

2196

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

2962

if(signal_received){

2963

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

2964

argv[0], signal_received,

2965

strsignal(signal_received));

2966

} else {

2967

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

2968

}

2197

2969

}

2198

2970

2199

2971

/* Cleanup things */

2972

free(mc.interfaces);

2973

2200

2974

if(sb != NULL)

2201

2975

avahi_s_service_browser_free(sb);

2202

2976

2203

2977

if(mc.server != NULL)

2204

2978

avahi_server_free(mc.server);

2205

2979

2206

if(mc.simple_poll != NULL)

2207

avahi_simple_poll_free(mc.simple_poll);

2980

if(simple_poll != NULL)

2981

avahi_simple_poll_free(simple_poll);

2208

2982

2209

2983

if(gnutls_initialized){

2210

2984

gnutls_certificate_free_credentials(mc.cred);

2211

gnutls_global_deinit();

2212

2985

gnutls_dh_params_deinit(mc.dh_params);

2213

2986

}

2214

2987

2222

2995

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

2223

2996

while(mc.current_server != NULL){

2224

2997

server *next = mc.current_server->next;

2998

#ifdef __GNUC__

2999

#pragma GCC diagnostic push

3000

#pragma GCC diagnostic ignored "-Wcast-qual"

3001

#endif

3002

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

3003

#ifdef __GNUC__

3004

#pragma GCC diagnostic pop

3005

#endif

2225

3006

free(mc.current_server);

2226

3007

mc.current_server = next;

2227

3008

}

2228

3009

}

2229

3010

2230

/* Run network hooks */

2231

run_network_hooks("stop", interface, delay);

2232

2233

/* Re-raise priviliges */

3011

/* Re-raise privileges */

2234

3012

{

2235

errno = 0;

2236

ret = seteuid(0);

2237

if(ret == -1){

2238

perror_plus("seteuid");

3013

ret = raise_privileges();

3014

if(ret != 0){

3015

errno = ret;

3016

perror_plus("Failed to raise privileges");

3017

} else {

3018

3019

/* Run network hooks */

3020

run_network_hooks("stop", interfaces_hooks != NULL ?

3021

interfaces_hooks : "", delay);

3022

3023

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

3024

{

3025

char *interface = NULL;

3026

while((interface=argz_next(interfaces_to_take_down,

3027

interfaces_to_take_down_size,

3028

interface))){

3029

ret = take_down_interface(interface);

3030

if(ret != 0){

3031

errno = ret;

3032

perror_plus("Failed to take down interface");

3033

}

3034

}

3035

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

3036

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

3037

" down\n");

3038

}

3039

}

2239

3040

}

2240

3041

2241

/* Take down the network interface */

2242

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

2243

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

2244

if(ret == -1){

2245

perror_plus("ioctl SIOCGIFFLAGS");

2246

} else if(network.ifr_flags & IFF_UP){

2247

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

2248

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

2249

if(ret == -1){

2250

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2251

}

2252

}

2253

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

2254

if(ret == -1){

2255

perror_plus("close");

2256

}

3042

ret = lower_privileges_permanently();

3043

if(ret != 0){

3044

errno = ret;

3045

perror_plus("Failed to lower privileges permanently");

2257

3046

}

2258

3047

}

2259

/* Lower privileges permanently */

2260

errno = 0;

2261

ret = setuid(uid);

2262

if(ret == -1){

2263

perror_plus("setuid");

3048

3049

free(interfaces_to_take_down);

3050

free(interfaces_hooks);

3051

3052

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

3053

uintmax_t level){

3054

struct dirent **direntries = NULL;

3055

int dret;

3056

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

3057

O_RDONLY

3058

| O_NOFOLLOW

3059

| O_DIRECTORY

3060

| O_PATH));

3061

if(dir_fd == -1){

3062

perror_plus("open");

3063

}

3064

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

3065

notdotentries, alphasort);

3066

if(numentries >= 0){

3067

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

3068

if(debug){

3069

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

3070

dirname, direntries[i]->d_name);

3071

}

3072

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

3073

if(dret == -1){

3074

if(errno == EISDIR){

3075

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

3076

AT_REMOVEDIR);

3077

}

3078

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

3079

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

3080

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

3081

/* Recurse only in this special case */

3082

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

3083

dret = 0;

3084

}

3085

if(dret == -1){

3086

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

3087

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

3088

}

3089

}

3090

free(direntries[i]);

3091

}

3092

3093

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

3094

free(direntries);

3095

if(numentries == -1){

3096

perror_plus("scandirat");

3097

}

3098

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3099

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

3100

perror_plus("rmdir");

3101

}

3102

} else {

3103

perror_plus("scandirat");

3104

}

3105

close(dir_fd);

2264

3106

}

2265

3107

2266

3108

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

2267

if(tempdir_created){

2268

struct dirent **direntries = NULL;

2269

struct dirent *direntry = NULL;

2270

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

2271

alphasort);

2272

if (numentries > 0){

2273

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

2274

direntry = direntries[i];

2275

char *fullname = NULL;

2276

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

2277

direntry->d_name);

2278

if(ret < 0){

2279

perror_plus("asprintf");

2280

continue;

2281

}

2282

ret = remove(fullname);

2283

if(ret == -1){

2284

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

2285

strerror(errno));

2286

}

2287

free(fullname);

2288

}

2289

}

2290

2291

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

2292

free(direntries);

2293

if (numentries == -1){

2294

perror_plus("scandir");

2295

}

2296

ret = rmdir(tempdir);

2297

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

2298

perror_plus("rmdir");

2299

}

3109

if(tempdir != NULL){

3110

clean_dir_at(-1, tempdir, 0);

2300

3111

}

2301

3112

2302

3113

if(quit_now){