/mandos/release : revision 237.7.94

9

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

10

*

11

* Everything else is

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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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

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42

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

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stdout, ferror() */

44

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

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stdout, ferror(), remove() */

44

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

45

#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() */

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

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

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

52

51

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

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52

#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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getnameinfo() */

61

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

58

inet_pton(), connect() */

59

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

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60

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

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61

*/

64

62

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

65

63

strtoimax() */

66

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

69

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

64

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

65

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

71

66

program_invocation_short_name */

72

67

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

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68

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

78

73

*/

79

74

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

80

75

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

81

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

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unlinkat() */

83

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

76

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

77

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

84

78

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

85

79

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

86

80

argp_state, struct argp,

94

88

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

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89

WEXITSTATUS(), WTERMSIG() */

96

90

#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() */

103

91

104

92

#ifdef __linux__

105

93

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

147

135

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

148

136

char *connect_to = NULL;

149

137

const char *hookdir = HOOKDIR;

150

int hookdir_fd = -1;

151

uid_t uid = 65534;

152

gid_t gid = 65534;

153

138

154

139

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

155

140

typedef struct server{

156

141

const char *ip;

157

in_port_t port;

142

uint16_t port;

158

143

AvahiIfIndex if_index;

159

144

int af;

160

145

struct timespec last_seen;

164

149

165

150

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

166

151

typedef struct {

152

AvahiSimplePoll *simple_poll;

167

153

AvahiServer *server;

168

154

gnutls_certificate_credentials_t cred;

169

155

unsigned int dh_bits;

171

157

const char *priority;

172

158

gpgme_ctx_t ctx;

173

159

server *current_server;

174

char *interfaces;

175

size_t interfaces_size;

176

160

} mandos_context;

177

161

178

/* global so signal handler can reach it*/

179

AvahiSimplePoll *simple_poll;

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 };

180

167

181

168

sig_atomic_t quit_now = 0;

182

169

int signal_received = 0;

190

177

perror(print_text);

191

178

}

192

179

193

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

180

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

194

181

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

195

182

va_list ap;

196

183

va_start (ap, format);

197

184

198

185

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

199

186

program_invocation_short_name));

200

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

187

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

201

188

}

202

189

203

190

/*

205

192

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

206

193

* "buffer_length" is how much is already used.

207

194

*/

208

__attribute__((nonnull, warn_unused_result))

209

195

size_t incbuffer(char **buffer, size_t buffer_length,

210

196

size_t buffer_capacity){

211

197

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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;

198

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

199

if(buffer == NULL){

218

200

return 0;

219

201

}

220

*buffer = new_buf;

221

202

buffer_capacity += BUFFER_SIZE;

222

203

}

223

204

return buffer_capacity;

224

205

}

225

206

226

207

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

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){

208

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

209

int af){

230

210

int ret;

231

211

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

232

212

if(new_server == NULL){

239

219

.af = af };

240

220

if(new_server->ip == NULL){

241

221

perror_plus("strdup");

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

222

return false;

258

223

}

259

224

/* Special case of first server */

260

if(*current_server == NULL){

225

if (mc.current_server == NULL){

261

226

new_server->next = new_server;

262

227

new_server->prev = new_server;

263

*current_server = new_server;

228

mc.current_server = new_server;

229

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

264

230

} else {

265

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

266

new_server->next = *current_server;

267

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

231

new_server->next = mc.current_server;

232

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

268

233

new_server->prev->next = new_server;

269

(*current_server)->prev = new_server;

234

mc.current_server->prev = new_server;

235

}

236

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

237

if(ret == -1){

238

perror_plus("clock_gettime");

239

return false;

270

240

}

271

241

return true;

272

242

}

274

244

/*

275

245

* Initialize GPGME.

276

246

*/

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){

247

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

248

const char *tempdir){

282

249

gpgme_error_t rc;

283

250

gpgme_engine_info_t engine_info;

284

251

252

285

253

/*

286

254

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

287

255

*/

288

bool import_key(const char * const filename){

256

bool import_key(const char *filename){

289

257

int ret;

290

258

int fd;

291

259

gpgme_data_t pgp_data;

303

271

return false;

304

272

}

305

273

306

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

274

rc = gpgme_op_import(mc.ctx, pgp_data);

307

275

if(rc != GPG_ERR_NO_ERROR){

308

276

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

309

277

gpgme_strsource(rc), gpgme_strerror(rc));

310

278

return false;

311

279

}

312

280

313

ret = close(fd);

281

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

314

282

if(ret == -1){

315

283

perror_plus("close");

316

284

}

353

321

}

354

322

355

323

/* Create new GPGME "context" */

356

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

324

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

357

325

if(rc != GPG_ERR_NO_ERROR){

358

326

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

359

327

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

372

340

* Decrypt OpenPGP data.

373

341

* Returns -1 on error

374

342

*/

375

__attribute__((nonnull, warn_unused_result))

376

343

static ssize_t pgp_packet_decrypt(const char *cryptotext,

377

344

size_t crypto_size,

378

char **plaintext,

379

mandos_context *mc){

345

char **plaintext){

380

346

gpgme_data_t dh_crypto, dh_plain;

381

347

gpgme_error_t rc;

382

348

ssize_t ret;

408

374

409

375

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

410

376

data buffer */

411

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

377

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

412

378

if(rc != GPG_ERR_NO_ERROR){

413

379

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

414

380

gpgme_strsource(rc), gpgme_strerror(rc));

415

381

plaintext_length = -1;

416

382

if(debug){

417

383

gpgme_decrypt_result_t result;

418

result = gpgme_op_decrypt_result(mc->ctx);

384

result = gpgme_op_decrypt_result(mc.ctx);

419

385

if(result == NULL){

420

386

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

421

387

} else {

498

464

return plaintext_length;

499

465

}

500

466

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);

467

static const char * safer_gnutls_strerror(int value){

468

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

469

-Wunreachable-code */

470

if(ret == NULL)

471

ret = "(unknown)";

472

return ret;

512

473

}

513

474

514

475

/* GnuTLS log function callback */

515

__attribute__((nonnull))

516

476

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

517

477

const char* string){

518

478

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

519

479

}

520

480

521

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

522

481

static int init_gnutls_global(const char *pubkeyfilename,

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

mandos_context *mc){

482

const char *seckeyfilename){

526

483

int ret;

527

unsigned int uret;

528

484

529

485

if(debug){

530

486

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

531

487

}

532

488

489

ret = gnutls_global_init();

490

if(ret != GNUTLS_E_SUCCESS){

491

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

492

safer_gnutls_strerror(ret));

493

return -1;

494

}

495

533

496

if(debug){

534

497

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

535

498

* - GnuTLS manual

539

502

}

540

503

541

504

/* OpenPGP credentials */

542

ret = gnutls_certificate_allocate_credentials(&mc->cred);

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

506

if(ret != GNUTLS_E_SUCCESS){

544

507

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

545

508

safer_gnutls_strerror(ret));

509

gnutls_global_deinit();

546

510

return -1;

547

511

}

548

512

554

518

}

555

519

556

520

ret = gnutls_certificate_set_openpgp_key_file

557

(mc->cred, pubkeyfilename, seckeyfilename,

521

(mc.cred, pubkeyfilename, seckeyfilename,

558

522

GNUTLS_OPENPGP_FMT_BASE64);

559

523

if(ret != GNUTLS_E_SUCCESS){

560

524

fprintf_plus(stderr,

566

530

}

567

531

568

532

/* GnuTLS server initialization */

569

ret = gnutls_dh_params_init(&mc->dh_params);

533

ret = gnutls_dh_params_init(&mc.dh_params);

570

534

if(ret != GNUTLS_E_SUCCESS){

571

535

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

572

536

" initialization: %s\n",

573

537

safer_gnutls_strerror(ret));

574

538

goto globalfail;

575

539

}

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);

540

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

541

if(ret != GNUTLS_E_SUCCESS){

542

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

543

safer_gnutls_strerror(ret));

544

goto globalfail;

545

}

546

547

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

750

548

751

549

return 0;

752

550

753

551

globalfail:

754

552

755

gnutls_certificate_free_credentials(mc->cred);

756

gnutls_dh_params_deinit(mc->dh_params);

553

gnutls_certificate_free_credentials(mc.cred);

554

gnutls_global_deinit();

555

gnutls_dh_params_deinit(mc.dh_params);

757

556

return -1;

758

557

}

759

558

760

__attribute__((nonnull, warn_unused_result))

761

static int init_gnutls_session(gnutls_session_t *session,

762

mandos_context *mc){

559

static int init_gnutls_session(gnutls_session_t *session){

763

560

int ret;

764

561

/* GnuTLS session creation */

765

562

do {

777

574

{

778

575

const char *err;

779

576

do {

780

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

577

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

781

578

if(quit_now){

782

579

gnutls_deinit(*session);

783

580

return -1;

794

591

795

592

do {

796

593

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

797

mc->cred);

594

mc.cred);

798

595

if(quit_now){

799

596

gnutls_deinit(*session);

800

597

return -1;

810

607

/* ignore client certificate if any. */

811

608

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

812

609

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

611

813

612

return 0;

814

613

}

815

614

817

616

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

818

617

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

819

618

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

1038

619

/* Called when a Mandos server is found */

1039

__attribute__((nonnull, warn_unused_result))

1040

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

620

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

1041

621

AvahiIfIndex if_index,

1042

int af, mandos_context *mc){

622

int af){

1043

623

int ret, tcp_sd = -1;

1044

624

ssize_t sret;

1045

struct sockaddr_storage to;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

1046

629

char *buffer = NULL;

1047

630

char *decrypted_buffer = NULL;

1048

631

size_t buffer_length = 0;

1051

634

int retval = -1;

1052

635

gnutls_session_t session;

1053

636

int pf; /* Protocol family */

1054

bool route_added = false;

1055

637

1056

638

errno = 0;

1057

639

1073

655

return -1;

1074

656

}

1075

657

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);

658

ret = init_gnutls_session(&session);

1109

659

if(ret != 0){

1110

660

return -1;

1111

661

}

1112

662

1113

663

if(debug){

1114

664

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

1115

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

665

PRIu16 "\n", ip, port);

1116

666

}

1117

667

1118

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

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1119

669

if(tcp_sd < 0){

1120

670

int e = errno;

1121

671

perror_plus("socket");

1128

678

goto mandos_end;

1129

679

}

1130

680

681

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

1131

682

if(af == AF_INET6){

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);

683

to.in6.sin6_family = (sa_family_t)af;

684

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

1135

685

} else { /* IPv4 */

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);

686

to.in.sin_family = (sa_family_t)af;

687

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

1139

688

}

1140

689

if(ret < 0 ){

1141

690

int e = errno;

1150

699

goto mandos_end;

1151

700

}

1152

701

if(af == AF_INET6){

1153

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

1154

if(IN6_IS_ADDR_LINKLOCAL

1155

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

702

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

703

-Wconversion and

704

-Wunreachable-code */

705

706

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

707

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

708

-Wunreachable-code*/

1156

709

if(if_index == AVAHI_IF_UNSPEC){

1157

710

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

1158

711

" incomplete without a network interface\n");

1160

713

goto mandos_end;

1161

714

}

1162

715

/* Set the network interface number as scope */

1163

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

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

717

}

1165

718

} else {

1166

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

719

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

720

-Wconversion and

721

-Wunreachable-code */

1167

722

}

1168

723

1169

724

if(quit_now){

1177

732

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

1178

733

perror_plus("if_indextoname");

1179

734

} else {

1180

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

1181

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

735

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

736

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

1182

737

}

1183

738

} else {

1184

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

1185

ip, (uintmax_t)port);

739

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

740

ip, port);

1186

741

}

1187

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1188

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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;

744

const char *pcret;

745

if(af == AF_INET6){

746

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

747

sizeof(addrstr));

748

} else {

749

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

750

sizeof(addrstr));

751

}

752

if(pcret == NULL){

753

perror_plus("inet_ntop");

754

} else {

755

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

756

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

757

}

758

}

759

}

760

761

if(quit_now){

762

errno = EINTR;

763

goto mandos_end;

764

}

765

766

if(af == AF_INET6){

767

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

768

} else {

769

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

770

}

771

if(ret < 0){

772

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

773

int e = errno;

774

perror_plus("connect");

775

errno = e;

776

}

777

goto mandos_end;

778

}

779

780

if(quit_now){

781

errno = EINTR;

782

goto mandos_end;

1269

783

}

1270

784

1271

785

const char *out = mandos_protocol_version;

1307

821

goto mandos_end;

1308

822

}

1309

823

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);

824

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

825

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1315

826

1316

827

if(quit_now){

1317

828

errno = EINTR;

1422

933

if(buffer_length > 0){

1423

934

ssize_t decrypted_buffer_size;

1424

935

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1425

&decrypted_buffer, mc);

936

&decrypted_buffer);

1426

937

if(decrypted_buffer_size >= 0){

1427

938

1428

clearerr(stdout);

1429

939

written = 0;

1430

940

while(written < (size_t) decrypted_buffer_size){

1431

941

if(quit_now){

1447

957

}

1448

958

written += (size_t)ret;

1449

959

}

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

}

1460

960

retval = 0;

1461

961

}

1462

962

}

1465

965

1466

966

mandos_end:

1467

967

{

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

}

1474

968

int e = errno;

1475

969

free(decrypted_buffer);

1476

970

free(buffer);

1477

971

if(tcp_sd >= 0){

1478

ret = close(tcp_sd);

972

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

1479

973

}

1480

974

if(ret == -1){

1481

975

if(e == 0){

1493

987

return retval;

1494

988

}

1495

989

1496

__attribute__((nonnull))

1497

990

static void resolve_callback(AvahiSServiceResolver *r,

1498

991

AvahiIfIndex interface,

1499

992

AvahiProtocol proto,

1507

1000

AVAHI_GCC_UNUSED AvahiStringList *txt,

1508

1001

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1509

1002

flags,

1510

void *mc){

1511

if(r == NULL){

1512

return;

1513

}

1003

AVAHI_GCC_UNUSED void* userdata){

1004

assert(r);

1514

1005

1515

1006

/* Called whenever a service has been resolved successfully or

1516

1007

timed out */

1517

1008

1518

1009

if(quit_now){

1519

avahi_s_service_resolver_free(r);

1520

1010

return;

1521

1011

}

1522

1012

1526

1016

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

1527

1017

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

1528

1018

domain,

1529

avahi_strerror(avahi_server_errno

1530

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

1019

avahi_strerror(avahi_server_errno(mc.server)));

1531

1020

break;

1532

1021

1533

1022

case AVAHI_RESOLVER_FOUND:

1539

1028

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

1540

1029

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

1541

1030

}

1542

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

1543

interface,

1544

avahi_proto_to_af(proto),

1545

mc);

1031

int ret = start_mandos_communication(ip, port, interface,

1032

avahi_proto_to_af(proto));

1546

1033

if(ret == 0){

1547

avahi_simple_poll_quit(simple_poll);

1034

avahi_simple_poll_quit(mc.simple_poll);

1548

1035

} else {

1549

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

1550

avahi_proto_to_af(proto),

1551

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

1036

if(not add_server(ip, port, interface,

1037

avahi_proto_to_af(proto))){

1552

1038

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

1553

1039

" list\n", name);

1554

1040

}

1567

1053

const char *domain,

1568

1054

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1569

1055

flags,

1570

void *mc){

1571

if(b == NULL){

1572

return;

1573

}

1056

AVAHI_GCC_UNUSED void* userdata){

1057

assert(b);

1574

1058

1575

1059

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

1576

1060

is removed from the LAN */

1584

1068

case AVAHI_BROWSER_FAILURE:

1585

1069

1586

1070

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

1587

avahi_strerror(avahi_server_errno

1588

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

1589

avahi_simple_poll_quit(simple_poll);

1071

avahi_strerror(avahi_server_errno(mc.server)));

1072

avahi_simple_poll_quit(mc.simple_poll);

1590

1073

return;

1591

1074

1592

1075

case AVAHI_BROWSER_NEW:

1595

1078

the callback function is called the Avahi server will free the

1596

1079

resolver for us. */

1597

1080

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)

1081

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

1082

name, type, domain, protocol, 0,

1083

resolve_callback, NULL) == NULL)

1602

1084

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

1603

1085

" %s\n", name,

1604

avahi_strerror(avahi_server_errno

1605

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

1086

avahi_strerror(avahi_server_errno(mc.server)));

1606

1087

break;

1607

1088

1608

1089

case AVAHI_BROWSER_REMOVE:

1627

1108

signal_received = sig;

1628

1109

int old_errno = errno;

1629

1110

/* set main loop to exit */

1630

if(simple_poll != NULL){

1631

avahi_simple_poll_quit(simple_poll);

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1632

1113

}

1633

1114

errno = old_errno;

1634

1115

}

1635

1116

1636

__attribute__((nonnull, warn_unused_result))

1637

1117

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

1638

1118

int ret;

1639

int old_errno;

1640

1119

1641

1120

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

1642

1121

if(s < 0){

1643

old_errno = errno;

1644

1122

perror_plus("socket");

1645

errno = old_errno;

1646

1123

return false;

1647

1124

}

1648

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

1649

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

1125

strcpy(ifr->ifr_name, ifname);

1650

1126

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1651

1127

if(ret == -1){

1652

1128

if(debug){

1653

old_errno = errno;

1654

1129

perror_plus("ioctl SIOCGIFFLAGS");

1655

errno = old_errno;

1656

1130

}

1657

1131

return false;

1658

1132

}

1659

1133

return true;

1660

1134

}

1661

1135

1662

__attribute__((nonnull, warn_unused_result))

1663

1136

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

1664

1137

1665

1138

/* Reject the loopback device */

1707

1180

* corresponds to an acceptable network device.

1708

1181

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

1709

1182

*/

1710

__attribute__((nonnull, warn_unused_result))

1711

1183

int good_interface(const struct dirent *if_entry){

1712

1184

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

1713

1185

return 0;

1729

1201

}

1730

1202

1731

1203

/*

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))

1204

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

1205

* corresponds to an acceptable network device which is up.

1206

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

1207

*/

1208

int up_interface(const struct dirent *if_entry){

1209

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

1210

return 0;

1211

}

1212

1213

struct ifreq ifr;

1214

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

1215

if(debug){

1216

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

1217

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

1218

}

1219

return 0;

1220

}

1221

1222

/* Reject down interfaces */

1223

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

1224

if(debug){

1225

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

1226

if_entry->d_name);

1227

}

1228

return 0;

1229

}

1230

1231

/* Reject non-running interfaces */

1232

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

1233

if(debug){

1234

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

1235

if_entry->d_name);

1236

}

1237

return 0;

1238

}

1239

1240

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

1241

return 0;

1242

}

1243

return 1;

1244

}

1245

1766

1246

int notdotentries(const struct dirent *direntry){

1767

1247

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

1768

1248

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

1775

1255

}

1776

1256

1777

1257

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

1778

__attribute__((nonnull, warn_unused_result))

1779

1258

int runnable_hook(const struct dirent *direntry){

1780

1259

int ret;

1781

1260

size_t sret;

1789

1268

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

1790

1269

"abcdefghijklmnopqrstuvwxyz"

1791

1270

"0123456789"

1792

"_.-");

1271

"_-");

1793

1272

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

1794

1273

/* Contains non-allowed characters */

1795

1274

if(debug){

1799

1278

return 0;

1800

1279

}

1801

1280

1802

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

1281

char *fullname = NULL;

1282

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

1283

if(ret < 0){

1284

perror_plus("asprintf");

1285

return 0;

1286

}

1287

1288

ret = stat(fullname, &st);

1803

1289

if(ret == -1){

1804

1290

if(debug){

1805

1291

perror_plus("Could not stat hook");

1829

1315

return 1;

1830

1316

}

1831

1317

1832

__attribute__((nonnull, warn_unused_result))

1833

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1834

mandos_context *mc){

1318

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1835

1319

int ret;

1836

1320

struct timespec now;

1837

1321

struct timespec waited_time;

1838

1322

intmax_t block_time;

1839

1323

1840

1324

while(true){

1841

if(mc->current_server == NULL){

1842

if(debug){

1325

if(mc.current_server == NULL){

1326

if (debug){

1843

1327

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

1844

1328

" No timeout!\n");

1845

1329

}

1846

1330

ret = avahi_simple_poll_iterate(s, -1);

1847

1331

} else {

1848

if(debug){

1332

if (debug){

1849

1333

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

1850

1334

" it, or wait\n");

1851

1335

}

1858

1342

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

1859

1343

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

1860

1344

waited_time.tv_sec = (now.tv_sec

1861

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

1345

- mc.current_server->last_seen.tv_sec);

1862

1346

waited_time.tv_nsec = (now.tv_nsec

1863

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

1347

- mc.current_server->last_seen.tv_nsec);

1864

1348

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

1865

1349

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

1866

1350

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

1868

1352

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

1869

1353

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

1870

1354

1871

if(debug){

1355

if (debug){

1872

1356

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

1873

1357

block_time);

1874

1358

}

1875

1359

1876

1360

if(block_time <= 0){

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);

1361

ret = start_mandos_communication(mc.current_server->ip,

1362

mc.current_server->port,

1363

mc.current_server->if_index,

1364

mc.current_server->af);

1881

1365

if(ret == 0){

1882

avahi_simple_poll_quit(s);

1366

avahi_simple_poll_quit(mc.simple_poll);

1883

1367

return 0;

1884

1368

}

1885

1369

ret = clock_gettime(CLOCK_MONOTONIC,

1886

&mc->current_server->last_seen);

1370

&mc.current_server->last_seen);

1887

1371

if(ret == -1){

1888

1372

perror_plus("clock_gettime");

1889

1373

return -1;

1890

1374

}

1891

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

1375

mc.current_server = mc.current_server->next;

1892

1376

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

1893

1377

servers, but don't block */

1894

1378

}

1896

1380

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

1897

1381

}

1898

1382

if(ret != 0){

1899

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

1383

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

1900

1384

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

1901

1385

}

1902

1386

}

1903

1387

}

1904

1388

}

1905

1389

1906

__attribute__((nonnull))

1907

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

1390

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

1908

1391

const float delay){

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);

1392

struct dirent **direntries;

1393

struct dirent *direntry;

1394

int ret;

1395

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

1396

alphasort);

1927

1397

if(numhooks == -1){

1928

1398

perror_plus("scandir");

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){

1399

} else {

1400

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

1401

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

1402

direntry = direntries[i];

1403

char *fullname = NULL;

1404

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

1405

if(ret < 0){

1990

1406

perror_plus("asprintf");

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1407

continue;

1408

}

1409

if(debug){

1410

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

1411

direntry->d_name);

1412

}

1413

pid_t hook_pid = fork();

1414

if(hook_pid == 0){

1415

/* Child */

1416

/* Raise privileges */

1417

errno = 0;

1418

ret = seteuid(0);

1419

if(ret == -1){

1420

perror_plus("seteuid");

1421

}

1422

/* Raise privileges even more */

1423

errno = 0;

1424

ret = setuid(0);

1425

if(ret == -1){

1426

perror_plus("setuid");

1427

}

1428

/* Set group */

1429

errno = 0;

1430

ret = setgid(0);

1431

if(ret == -1){

1432

perror_plus("setgid");

1433

}

1434

/* Reset supplementary groups */

1435

errno = 0;

1436

ret = setgroups(0, NULL);

1437

if(ret == -1){

1438

perror_plus("setgroups");

1439

}

1440

dup2(devnull, STDIN_FILENO);

1441

close(devnull);

1442

dup2(STDERR_FILENO, STDOUT_FILENO);

1443

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

1444

if(ret == -1){

1445

perror_plus("setenv");

1446

_exit(EX_OSERR);

1447

}

1448

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

1449

if(ret == -1){

1450

perror_plus("setenv");

1451

_exit(EX_OSERR);

1452

}

1453

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

1454

if(ret == -1){

1455

perror_plus("setenv");

1456

_exit(EX_OSERR);

1457

}

1458

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

1459

if(ret == -1){

1460

perror_plus("setenv");

1461

_exit(EX_OSERR);

1462

}

1463

char *delaystring;

1464

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

1465

if(ret == -1){

1466

perror_plus("asprintf");

1467

_exit(EX_OSERR);

1468

}

1469

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

1470

if(ret == -1){

1471

free(delaystring);

1472

perror_plus("setenv");

1473

_exit(EX_OSERR);

1474

}

1995

1475

free(delaystring);

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;

1476

if(connect_to != NULL){

1477

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

1478

if(ret == -1){

1479

perror_plus("setenv");

1480

_exit(EX_OSERR);

1481

}

1482

}

1483

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

1484

perror_plus("execl");

1485

_exit(EXIT_FAILURE);

1486

}

1487

} else {

1488

int status;

1489

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

1490

perror_plus("waitpid");

1491

free(fullname);

1492

continue;

1493

}

1494

if(WIFEXITED(status)){

1495

if(WEXITSTATUS(status) != 0){

1496

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

1497

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

1498

WEXITSTATUS(status));

1499

free(fullname);

1500

continue;

1501

}

1502

} else if(WIFSIGNALED(status)){

1503

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

1504

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

1505

WTERMSIG(status));

1506

free(fullname);

1507

continue;

1508

} else {

1509

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

1510

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

1511

free(fullname);

1512

continue;

1513

}

1514

}

1515

free(fullname);

1516

if(debug){

1517

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

1518

direntry->d_name);

1519

}

1520

}

1521

close(devnull);

1522

}

1523

return true;

2288

1524

}

2289

1525

2290

1526

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 };

2296

1527

AvahiSServiceBrowser *sb = NULL;

2297

error_t ret_errno;

1528

int error;

2298

1529

int ret;

2299

1530

intmax_t tmpmax;

2300

1531

char *tmp;

2301

1532

int exitcode = EXIT_SUCCESS;

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;

1533

const char *interface = "";

1534

struct ifreq network;

1535

int sd = -1;

1536

bool take_down_interface = false;

1537

uid_t uid;

1538

gid_t gid;

1539

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

1540

bool tempdir_created = false;

2307

1541

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2308

1542

const char *seckey = PATHDIR "/" SECKEY;

2309

1543

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

2311

char *interfaces_hooks = NULL;

2312

1544

2313

1545

bool gnutls_initialized = false;

2314

1546

bool gpgme_initialized = false;

2366

1598

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

2367

1599

" Diffie-Hellman key exchange",

2368

1600

.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 },

2374

1601

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

2375

1602

.arg = "STRING",

2376

1603

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

2410

1637

connect_to = arg;

2411

1638

break;

2412

1639

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

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

}

1640

interface = arg;

2418

1641

break;

2419

1642

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

2420

1643

seckey = arg;

2431

1654

}

2432

1655

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

2433

1656

break;

2434

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

2435

dh_params_file = arg;

2436

break;

2437

1657

case 130: /* --priority */

2438

1658

mc.priority = arg;

2439

1659

break;

2479

1699

.args_doc = "",

2480

1700

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

2481

1701

" passwords from a Mandos server" };

2482

ret_errno = argp_parse(&argp, argc, argv,

2483

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2484

switch(ret_errno){

1702

ret = argp_parse(&argp, argc, argv,

1703

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1704

switch(ret){

2485

1705

case 0:

2486

1706

break;

2487

1707

case ENOMEM:

2488

1708

default:

2489

errno = ret_errno;

1709

errno = ret;

2490

1710

perror_plus("argp_parse");

2491

1711

exitcode = EX_OSERR;

2492

1712

goto end;

2495

1715

goto end;

2496

1716

}

2497

1717

}

2498

1718

2499

1719

{

2500

1720

/* Work around Debian bug #633582:

2501

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

1721

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

2502

1722

2503

/* Re-raise privileges */

2504

ret = raise_privileges();

2505

if(ret != 0){

2506

errno = ret;

2507

perror_plus("Failed to raise privileges");

1723

/* Re-raise priviliges */

1724

errno = 0;

1725

ret = seteuid(0);

1726

if(ret == -1){

1727

perror_plus("seteuid");

2508

1728

} else {

2509

1729

struct stat st;

2510

1730

2525

1745

}

2526

1746

}

2527

1747

}

2528

close(seckey_fd);

1748

TEMP_FAILURE_RETRY(close(seckey_fd));

2529

1749

}

2530

1750

}

2531

1751

2532

1752

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

2533

1753

int pubkey_fd = open(pubkey, O_RDONLY);

2534

1754

if(pubkey_fd == -1){

2546

1766

}

2547

1767

}

2548

1768

}

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

1769

TEMP_FAILURE_RETRY(close(pubkey_fd));

1770

}

1771

}

1772

2575

1773

/* Lower privileges */

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;

1774

errno = 0;

1775

ret = seteuid(uid);

1776

if(ret == -1){

1777

perror_plus("seteuid");

2597

1778

}

2598

1779

}

2599

1780

}

2600

1781

2601

1782

/* Run network hooks */

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);

1783

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

1784

goto end;

2614

1785

}

2615

1786

2616

1787

if(not debug){

2617

1788

avahi_set_log_function(empty_log);

2618

1789

}

2619

1790

1791

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

1792

struct dirent **direntries;

1793

/* First look for interfaces that are up */

1794

ret = scandir(sys_class_net, &direntries, up_interface,

1795

alphasort);

1796

if(ret == 0){

1797

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

1798

free(direntries);

1799

ret = scandir(sys_class_net, &direntries, good_interface,

1800

alphasort);

1801

}

1802

if(ret >= 1){

1803

/* Pick the first interface returned */

1804

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

1805

if(debug){

1806

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

1807

}

1808

if(interface == NULL){

1809

perror_plus("malloc");

1810

free(direntries);

1811

exitcode = EXIT_FAILURE;

1812

goto end;

1813

}

1814

free(direntries);

1815

} else {

1816

free(direntries);

1817

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

1818

exitcode = EXIT_FAILURE;

1819

goto end;

1820

}

1821

}

1822

2620

1823

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

2621

1824

from the signal handler */

2622

1825

/* Initialize the pseudo-RNG for Avahi */

2623

1826

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

2624

simple_poll = avahi_simple_poll_new();

2625

if(simple_poll == NULL){

1827

mc.simple_poll = avahi_simple_poll_new();

1828

if(mc.simple_poll == NULL){

2626

1829

fprintf_plus(stderr,

2627

1830

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

2628

1831

exitcode = EX_UNAVAILABLE;

2692

1895

}

2693

1896

}

2694

1897

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;

1898

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

1899

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

1900

if_index = (AvahiIfIndex) if_nametoindex(interface);

1901

if(if_index == 0){

1902

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

1903

exitcode = EX_UNAVAILABLE;

1904

goto end;

1905

}

1906

1907

if(quit_now){

1908

goto end;

1909

}

1910

1911

/* Re-raise priviliges */

1912

errno = 0;

1913

ret = seteuid(0);

1914

if(ret == -1){

1915

perror_plus("seteuid");

1916

}

1917

1918

#ifdef __linux__

1919

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1920

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

1921

ret = klogctl(8, NULL, 5);

1922

bool restore_loglevel = true;

1923

if(ret == -1){

1924

restore_loglevel = false;

1925

perror_plus("klogctl");

1926

}

1927

#endif /* __linux__ */

1928

1929

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1930

if(sd < 0){

1931

perror_plus("socket");

1932

exitcode = EX_OSERR;

1933

#ifdef __linux__

1934

if(restore_loglevel){

1935

ret = klogctl(7, NULL, 0);

1936

if(ret == -1){

1937

perror_plus("klogctl");

1938

}

1939

}

1940

#endif /* __linux__ */

1941

/* Lower privileges */

1942

errno = 0;

1943

ret = seteuid(uid);

1944

if(ret == -1){

1945

perror_plus("seteuid");

1946

}

1947

goto end;

1948

}

1949

strcpy(network.ifr_name, interface);

1950

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

1951

if(ret == -1){

1952

perror_plus("ioctl SIOCGIFFLAGS");

1953

#ifdef __linux__

1954

if(restore_loglevel){

1955

ret = klogctl(7, NULL, 0);

1956

if(ret == -1){

1957

perror_plus("klogctl");

1958

}

1959

}

1960

#endif /* __linux__ */

1961

exitcode = EX_OSERR;

1962

/* Lower privileges */

1963

errno = 0;

1964

ret = seteuid(uid);

1965

if(ret == -1){

1966

perror_plus("seteuid");

1967

}

1968

goto end;

1969

}

1970

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

1971

network.ifr_flags |= IFF_UP;

1972

take_down_interface = true;

1973

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

1974

if(ret == -1){

1975

take_down_interface = false;

1976

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1977

exitcode = EX_OSERR;

1978

#ifdef __linux__

1979

if(restore_loglevel){

1980

ret = klogctl(7, NULL, 0);

1981

if(ret == -1){

1982

perror_plus("klogctl");

2746

1983

}

2747

1984

}

1985

#endif /* __linux__ */

1986

/* Lower privileges */

1987

errno = 0;

1988

ret = seteuid(uid);

1989

if(ret == -1){

1990

perror_plus("seteuid");

1991

}

1992

goto end;

1993

}

1994

}

1995

/* Sleep checking until interface is running.

1996

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

1997

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

1998

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

1999

if(ret == -1){

2000

perror_plus("ioctl SIOCGIFFLAGS");

2001

} else if(network.ifr_flags & IFF_RUNNING){

2748

2002

break;

2749

2003

}

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);

2004

struct timespec sleeptime = { .tv_nsec = 250000000 };

2005

ret = nanosleep(&sleeptime, NULL);

2006

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

2007

perror_plus("nanosleep");

2008

}

2009

}

2010

if(not take_down_interface){

2011

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

2012

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

2013

if(ret == -1){

2014

perror_plus("close");

2015

}

2016

}

2017

#ifdef __linux__

2018

if(restore_loglevel){

2019

/* Restores kernel loglevel to default */

2020

ret = klogctl(7, NULL, 0);

2021

if(ret == -1){

2022

perror_plus("klogctl");

2023

}

2024

}

2025

#endif /* __linux__ */

2026

/* Lower privileges */

2027

errno = 0;

2028

/* Lower privileges */

2029

ret = seteuid(uid);

2030

if(ret == -1){

2031

perror_plus("seteuid");

2032

}

2778

2033

}

2779

2034

2780

2035

if(quit_now){

2781

2036

goto end;

2782

2037

}

2783

2038

2784

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

2039

ret = init_gnutls_global(pubkey, seckey);

2785

2040

if(ret == -1){

2786

2041

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

2787

2042

exitcode = EX_UNAVAILABLE;

2794

2049

goto end;

2795

2050

}

2796

2051

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){

2052

if(mkdtemp(tempdir) == NULL){

2807

2053

perror_plus("mkdtemp");

2808

2054

goto end;

2809

2055

}

2056

tempdir_created = true;

2810

2057

2811

2058

if(quit_now){

2812

2059

goto end;

2813

2060

}

2814

2061

2815

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

2062

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

2816

2063

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

2817

2064

exitcode = EX_UNAVAILABLE;

2818

2065

goto end;

2828

2075

/* Connect directly, do not use Zeroconf */

2829

2076

/* (Mainly meant for debugging) */

2830

2077

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

2831

2832

2078

if(address == NULL){

2833

2079

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

2834

2080

exitcode = EX_USAGE;

2839

2085

goto end;

2840

2086

}

2841

2087

2842

in_port_t port;

2088

uint16_t port;

2843

2089

errno = 0;

2844

2090

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

2845

2091

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

2846

or tmpmax != (in_port_t)tmpmax){

2092

or tmpmax != (uint16_t)tmpmax){

2847

2093

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

2848

2094

exitcode = EX_USAGE;

2849

2095

goto end;

2850

2096

}

2851

2097

2852

2098

if(quit_now){

2853

2099

goto end;

2854

2100

}

2855

2101

2856

port = (in_port_t)tmpmax;

2102

port = (uint16_t)tmpmax;

2857

2103

*address = '\0';

2858

2104

/* Colon in address indicates IPv6 */

2859

2105

int af;

2875

2121

}

2876

2122

2877

2123

while(not quit_now){

2878

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

2879

&mc);

2124

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

2880

2125

if(quit_now or ret == 0){

2881

2126

break;

2882

2127

}

2884

2129

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

2885

2130

(int)retry_interval);

2886

2131

}

2887

sleep((unsigned int)retry_interval);

2132

sleep((int)retry_interval);

2888

2133

}

2889

2134

2890

if(not quit_now){

2135

if (not quit_now){

2891

2136

exitcode = EXIT_SUCCESS;

2892

2137

}

2893

2138

2908

2153

config.publish_domain = 0;

2909

2154

2910

2155

/* Allocate a new server */

2911

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2912

&config, NULL, NULL, &ret);

2156

mc.server = avahi_server_new(avahi_simple_poll_get

2157

(mc.simple_poll), &config, NULL,

2158

NULL, &error);

2913

2159

2914

2160

/* Free the Avahi configuration data */

2915

2161

avahi_server_config_free(&config);

2918

2164

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

2919

2165

if(mc.server == NULL){

2920

2166

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

2921

avahi_strerror(ret));

2167

avahi_strerror(error));

2922

2168

exitcode = EX_UNAVAILABLE;

2923

2169

goto end;

2924

2170

}

2930

2176

/* Create the Avahi service browser */

2931

2177

sb = avahi_s_service_browser_new(mc.server, if_index,

2932

2178

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2933

NULL, 0, browse_callback,

2934

(void *)&mc);

2179

NULL, 0, browse_callback, NULL);

2935

2180

if(sb == NULL){

2936

2181

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

2937

2182

avahi_strerror(avahi_server_errno(mc.server)));

2948

2193

if(debug){

2949

2194

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

2950

2195

}

2951

2952

ret = avahi_loop_with_timeout(simple_poll,

2953

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

2196

2197

ret = avahi_loop_with_timeout(mc.simple_poll,

2198

(int)(retry_interval * 1000));

2954

2199

if(debug){

2955

2200

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

2956

2201

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

2959

2204

end:

2960

2205

2961

2206

if(debug){

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

}

2207

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

2969

2208

}

2970

2209

2971

2210

/* Cleanup things */

2972

free(mc.interfaces);

2973

2974

2211

if(sb != NULL)

2975

2212

avahi_s_service_browser_free(sb);

2976

2213

2977

2214

if(mc.server != NULL)

2978

2215

avahi_server_free(mc.server);

2979

2216

2980

if(simple_poll != NULL)

2981

avahi_simple_poll_free(simple_poll);

2217

if(mc.simple_poll != NULL)

2218

avahi_simple_poll_free(mc.simple_poll);

2982

2219

2983

2220

if(gnutls_initialized){

2984

2221

gnutls_certificate_free_credentials(mc.cred);

2222

gnutls_global_deinit();

2985

2223

gnutls_dh_params_deinit(mc.dh_params);

2986

2224

}

2987

2225

2995

2233

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

2996

2234

while(mc.current_server != NULL){

2997

2235

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

3006

2236

free(mc.current_server);

3007

2237

mc.current_server = next;

3008

2238

}

3009

2239

}

3010

2240

3011

/* Re-raise privileges */

2241

/* Run network hooks */

2242

run_network_hooks("stop", interface, delay);

2243

2244

/* Re-raise priviliges */

3012

2245

{

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

}

2246

errno = 0;

2247

ret = seteuid(0);

2248

if(ret == -1){

2249

perror_plus("seteuid");

3040

2250

}

3041

2251

3042

ret = lower_privileges_permanently();

3043

if(ret != 0){

3044

errno = ret;

3045

perror_plus("Failed to lower privileges permanently");

2252

/* Take down the network interface */

2253

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

2254

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

2255

if(ret == -1){

2256

perror_plus("ioctl SIOCGIFFLAGS");

2257

} else if(network.ifr_flags & IFF_UP){

2258

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

2259

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

2260

if(ret == -1){

2261

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2262

}

2263

}

2264

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

2265

if(ret == -1){

2266

perror_plus("close");

2267

}

3046

2268

}

3047

2269

}

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){

2270

/* Lower privileges permanently */

2271

errno = 0;

2272

ret = setuid(uid);

2273

if(ret == -1){

2274

perror_plus("setuid");

2275

}

2276

2277

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

2278

if(tempdir_created){

3054

2279

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){

2280

struct dirent *direntry = NULL;

2281

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

2282

alphasort);

2283

if (numentries > 0){

3067

2284

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);

3106

}

3107

3108

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

3109

if(tempdir != NULL){

3110

clean_dir_at(-1, tempdir, 0);

2285

direntry = direntries[i];

2286

char *fullname = NULL;

2287

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

2288

direntry->d_name);

2289

if(ret < 0){

2290

perror_plus("asprintf");

2291

continue;

2292

}

2293

ret = remove(fullname);

2294

if(ret == -1){

2295

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

2296

strerror(errno));

2297

}

2298

free(fullname);

2299

}

2300

}

2301

2302

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

2303

free(direntries);

2304

if (numentries == -1){

2305

perror_plus("scandir");

2306

}

2307

ret = rmdir(tempdir);

2308

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

2309

perror_plus("rmdir");

2310

}

3111

2311

}

3112

2312

3113

2313

if(quit_now){