/mandos/trunk : revision 505.3.26

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 */

46

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

47

strtof(), abort() */

48

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

49

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

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asprintf(), strncpy() */

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

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

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

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#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() */

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

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inet_pton(), connect() */

59

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

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

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61

*/

63

62

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

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63

strtoimax() */

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

69

ENOTEMPTY,

64

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

65

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

70

66

program_invocation_short_name */

71

67

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

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68

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

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73

*/

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74

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

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75

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

80

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

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unlinkat() */

82

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

76

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

77

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

83

78

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

84

79

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

85

80

argp_state, struct argp,

93

88

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

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89

WEXITSTATUS(), WTERMSIG() */

95

90

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

96

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

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

99

argz_count() */

100

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

101

EAI_SYSTEM, gai_strerror() */

102

91

103

92

#ifdef __linux__

104

93

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

146

135

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

147

136

char *connect_to = NULL;

148

137

const char *hookdir = HOOKDIR;

149

int hookdir_fd = -1;

150

uid_t uid = 65534;

151

gid_t gid = 65534;

152

138

153

139

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

154

140

typedef struct server{

155

141

const char *ip;

156

in_port_t port;

142

uint16_t port;

157

143

AvahiIfIndex if_index;

158

144

int af;

159

145

struct timespec last_seen;

163

149

164

150

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

165

151

typedef struct {

152

AvahiSimplePoll *simple_poll;

166

153

AvahiServer *server;

167

154

gnutls_certificate_credentials_t cred;

168

155

unsigned int dh_bits;

170

157

const char *priority;

171

158

gpgme_ctx_t ctx;

172

159

server *current_server;

173

char *interfaces;

174

size_t interfaces_size;

175

160

} mandos_context;

176

161

177

/* global so signal handler can reach it*/

178

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 };

179

167

180

168

sig_atomic_t quit_now = 0;

181

169

int signal_received = 0;

182

170

183

171

/* Function to use when printing errors */

184

172

void perror_plus(const char *print_text){

185

int e = errno;

186

173

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

187

174

program_invocation_short_name);

188

errno = e;

189

175

perror(print_text);

190

176

}

191

177

192

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

193

178

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

194

179

va_list ap;

195

180

va_start (ap, format);

196

181

197

182

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

198

183

program_invocation_short_name));

199

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

184

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

200

185

}

201

186

202

187

/*

204

189

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

205

190

* "buffer_length" is how much is already used.

206

191

*/

207

__attribute__((nonnull, warn_unused_result))

208

192

size_t incbuffer(char **buffer, size_t buffer_length,

209

193

size_t buffer_capacity){

210

194

if(buffer_length + BUFFER_SIZE > buffer_capacity){

211

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

212

if(new_buf == NULL){

213

int old_errno = errno;

214

free(*buffer);

215

errno = old_errno;

216

*buffer = NULL;

195

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

196

if(buffer == NULL){

217

197

return 0;

218

198

}

219

*buffer = new_buf;

220

199

buffer_capacity += BUFFER_SIZE;

221

200

}

222

201

return buffer_capacity;

223

202

}

224

203

225

204

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

226

__attribute__((nonnull, warn_unused_result))

227

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

228

int af, server **current_server){

205

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

206

int af){

229

207

int ret;

230

208

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

231

209

if(new_server == NULL){

232

210

perror_plus("malloc");

233

return false;

211

return -1;

234

212

}

235

213

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

236

214

.port = port,

238

216

.af = af };

239

217

if(new_server->ip == NULL){

240

218

perror_plus("strdup");

241

free(new_server);

242

return false;

243

}

244

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

245

if(ret == -1){

246

perror_plus("clock_gettime");

247

#ifdef __GNUC__

248

#pragma GCC diagnostic push

249

#pragma GCC diagnostic ignored "-Wcast-qual"

250

#endif

251

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

252

#ifdef __GNUC__

253

#pragma GCC diagnostic pop

254

#endif

255

free(new_server);

256

return false;

219

return -1;

257

220

}

258

221

/* Special case of first server */

259

if(*current_server == NULL){

222

if (mc.current_server == NULL){

260

223

new_server->next = new_server;

261

224

new_server->prev = new_server;

262

*current_server = new_server;

225

mc.current_server = new_server;

226

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

263

227

} else {

264

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

265

new_server->next = *current_server;

266

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

228

new_server->next = mc.current_server;

229

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

267

230

new_server->prev->next = new_server;

268

(*current_server)->prev = new_server;

269

}

270

return true;

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;

271

239

}

272

240

273

241

/*

274

242

* Initialize GPGME.

275

243

*/

276

__attribute__((nonnull, warn_unused_result))

277

static bool init_gpgme(const char * const seckey,

278

const char * const pubkey,

279

const char * const tempdir,

280

mandos_context *mc){

244

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

245

const char *tempdir){

281

246

gpgme_error_t rc;

282

247

gpgme_engine_info_t engine_info;

283

248

249

284

250

/*

285

251

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

286

252

*/

287

bool import_key(const char * const filename){

253

bool import_key(const char *filename){

288

254

int ret;

289

255

int fd;

290

256

gpgme_data_t pgp_data;

302

268

return false;

303

269

}

304

270

305

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

271

rc = gpgme_op_import(mc.ctx, pgp_data);

306

272

if(rc != GPG_ERR_NO_ERROR){

307

273

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

308

274

gpgme_strsource(rc), gpgme_strerror(rc));

309

275

return false;

310

276

}

311

277

312

ret = close(fd);

278

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

313

279

if(ret == -1){

314

280

perror_plus("close");

315

281

}

352

318

}

353

319

354

320

/* Create new GPGME "context" */

355

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

321

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

356

322

if(rc != GPG_ERR_NO_ERROR){

357

323

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

358

324

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

371

337

* Decrypt OpenPGP data.

372

338

* Returns -1 on error

373

339

*/

374

__attribute__((nonnull, warn_unused_result))

375

340

static ssize_t pgp_packet_decrypt(const char *cryptotext,

376

341

size_t crypto_size,

377

char **plaintext,

378

mandos_context *mc){

342

char **plaintext){

379

343

gpgme_data_t dh_crypto, dh_plain;

380

344

gpgme_error_t rc;

381

345

ssize_t ret;

407

371

408

372

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

409

373

data buffer */

410

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

374

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

411

375

if(rc != GPG_ERR_NO_ERROR){

412

376

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

413

377

gpgme_strsource(rc), gpgme_strerror(rc));

414

378

plaintext_length = -1;

415

379

if(debug){

416

380

gpgme_decrypt_result_t result;

417

result = gpgme_op_decrypt_result(mc->ctx);

381

result = gpgme_op_decrypt_result(mc.ctx);

418

382

if(result == NULL){

419

383

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

420

384

} else {

497

461

return plaintext_length;

498

462

}

499

463

500

__attribute__((warn_unused_result, const))

501

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

502

if(str == NULL)

503

return "(unknown)";

504

return str;

505

}

506

507

__attribute__((warn_unused_result))

508

static const char *safer_gnutls_strerror(int value){

509

const char *ret = gnutls_strerror(value);

510

return safe_string(ret);

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;

511

470

}

512

471

513

472

/* GnuTLS log function callback */

514

__attribute__((nonnull))

515

473

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

516

474

const char* string){

517

475

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

518

476

}

519

477

520

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

521

478

static int init_gnutls_global(const char *pubkeyfilename,

522

const char *seckeyfilename,

523

const char *dhparamsfilename,

524

mandos_context *mc){

479

const char *seckeyfilename){

525

480

int ret;

526

unsigned int uret;

527

481

528

482

if(debug){

529

483

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

530

484

}

531

485

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

532

493

if(debug){

533

494

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

534

495

* - GnuTLS manual

538

499

}

539

500

540

501

/* OpenPGP credentials */

541

ret = gnutls_certificate_allocate_credentials(&mc->cred);

502

ret = gnutls_certificate_allocate_credentials(&mc.cred);

542

503

if(ret != GNUTLS_E_SUCCESS){

543

504

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

544

505

safer_gnutls_strerror(ret));

506

gnutls_global_deinit();

545

507

return -1;

546

508

}

547

509

553

515

}

554

516

555

517

ret = gnutls_certificate_set_openpgp_key_file

556

(mc->cred, pubkeyfilename, seckeyfilename,

518

(mc.cred, pubkeyfilename, seckeyfilename,

557

519

GNUTLS_OPENPGP_FMT_BASE64);

558

520

if(ret != GNUTLS_E_SUCCESS){

559

521

fprintf_plus(stderr,

565

527

}

566

528

567

529

/* GnuTLS server initialization */

568

ret = gnutls_dh_params_init(&mc->dh_params);

530

ret = gnutls_dh_params_init(&mc.dh_params);

569

531

if(ret != GNUTLS_E_SUCCESS){

570

532

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

571

533

" initialization: %s\n",

572

534

safer_gnutls_strerror(ret));

573

535

goto globalfail;

574

536

}

575

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

576

if(dhparamsfilename != NULL){

577

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

578

do {

579

int dhpfile = open(dhparamsfilename, O_RDONLY);

580

if(dhpfile == -1){

581

perror_plus("open");

582

dhparamsfilename = NULL;

583

break;

584

}

585

size_t params_capacity = 0;

586

while(true){

587

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

588

(size_t)params.size,

589

(size_t)params_capacity);

590

if(params_capacity == 0){

591

perror_plus("incbuffer");

592

free(params.data);

593

params.data = NULL;

594

dhparamsfilename = NULL;

595

break;

596

}

597

ssize_t bytes_read = read(dhpfile,

598

params.data + params.size,

599

BUFFER_SIZE);

600

/* EOF */

601

if(bytes_read == 0){

602

break;

603

}

604

/* check bytes_read for failure */

605

if(bytes_read < 0){

606

perror_plus("read");

607

free(params.data);

608

params.data = NULL;

609

dhparamsfilename = NULL;

610

break;

611

}

612

params.size += (unsigned int)bytes_read;

613

}

614

if(params.data == NULL){

615

dhparamsfilename = NULL;

616

}

617

if(dhparamsfilename == NULL){

618

break;

619

}

620

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

621

GNUTLS_X509_FMT_PEM);

622

if(ret != GNUTLS_E_SUCCESS){

623

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

624

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

625

safer_gnutls_strerror(ret));

626

dhparamsfilename = NULL;

627

}

628

} while(false);

629

}

630

if(dhparamsfilename == NULL){

631

if(mc->dh_bits == 0){

632

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

633

/* Try to read the private key file */

634

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

635

do {

636

int secfile = open(seckeyfilename, O_RDONLY);

637

if(secfile == -1){

638

perror_plus("open");

639

break;

640

}

641

size_t buffer_capacity = 0;

642

while(true){

643

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

644

(size_t)buffer.size,

645

(size_t)buffer_capacity);

646

if(buffer_capacity == 0){

647

perror_plus("incbuffer");

648

free(buffer.data);

649

buffer.data = NULL;

650

break;

651

}

652

ssize_t bytes_read = read(secfile,

653

buffer.data + buffer.size,

654

BUFFER_SIZE);

655

/* EOF */

656

if(bytes_read == 0){

657

break;

658

}

659

/* check bytes_read for failure */

660

if(bytes_read < 0){

661

perror_plus("read");

662

free(buffer.data);

663

buffer.data = NULL;

664

break;

665

}

666

buffer.size += (unsigned int)bytes_read;

667

}

668

close(secfile);

669

} while(false);

670

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

671

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

672

if(buffer.data != NULL){

673

{

674

gnutls_openpgp_privkey_t privkey = NULL;

675

ret = gnutls_openpgp_privkey_init(&privkey);

676

if(ret != GNUTLS_E_SUCCESS){

677

fprintf_plus(stderr, "Error initializing OpenPGP key"

678

" structure: %s",

679

safer_gnutls_strerror(ret));

680

free(buffer.data);

681

buffer.data = NULL;

682

} else {

683

ret = gnutls_openpgp_privkey_import

684

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

685

if(ret != GNUTLS_E_SUCCESS){

686

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

687

safer_gnutls_strerror(ret));

688

privkey = NULL;

689

}

690

free(buffer.data);

691

buffer.data = NULL;

692

if(privkey != NULL){

693

/* Use private key to suggest an appropriate

694

sec_param */

695

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

696

gnutls_openpgp_privkey_deinit(privkey);

697

if(debug){

698

fprintf_plus(stderr, "This OpenPGP key implies using"

699

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

700

safe_string(gnutls_sec_param_get_name

701

(sec_param)));

702

}

703

}

704

}

705

}

706

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

707

/* Err on the side of caution */

708

sec_param = GNUTLS_SEC_PARAM_ULTRA;

709

if(debug){

710

fprintf_plus(stderr, "Falling back to security parameter"

711

" \"%s\"\n",

712

safe_string(gnutls_sec_param_get_name

713

(sec_param)));

714

}

715

}

716

}

717

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

718

if(uret != 0){

719

mc->dh_bits = uret;

720

if(debug){

721

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

722

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

723

safe_string(gnutls_sec_param_get_name

724

(sec_param)),

725

mc->dh_bits);

726

}

727

} else {

728

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

729

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

730

safe_string(gnutls_sec_param_get_name

731

(sec_param)),

732

safer_gnutls_strerror(ret));

733

goto globalfail;

734

}

735

} else if(debug){

736

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

737

mc->dh_bits);

738

}

739

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

740

if(ret != GNUTLS_E_SUCCESS){

741

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

742

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

743

safer_gnutls_strerror(ret));

744

goto globalfail;

745

}

746

}

747

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

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);

748

545

749

546

return 0;

750

547

751

548

globalfail:

752

549

753

gnutls_certificate_free_credentials(mc->cred);

754

gnutls_dh_params_deinit(mc->dh_params);

550

gnutls_certificate_free_credentials(mc.cred);

551

gnutls_global_deinit();

552

gnutls_dh_params_deinit(mc.dh_params);

755

553

return -1;

756

554

}

757

555

758

__attribute__((nonnull, warn_unused_result))

759

static int init_gnutls_session(gnutls_session_t *session,

760

mandos_context *mc){

556

static int init_gnutls_session(gnutls_session_t *session){

761

557

int ret;

762

558

/* GnuTLS session creation */

763

559

do {

775

571

{

776

572

const char *err;

777

573

do {

778

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

574

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

779

575

if(quit_now){

780

576

gnutls_deinit(*session);

781

577

return -1;

792

588

793

589

do {

794

590

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

795

mc->cred);

591

mc.cred);

796

592

if(quit_now){

797

593

gnutls_deinit(*session);

798

594

return -1;

808

604

/* ignore client certificate if any. */

809

605

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

810

606

607

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

608

811

609

return 0;

812

610

}

813

611

815

613

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

816

614

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

817

615

818

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

819

__attribute__((warn_unused_result))

820

int raise_privileges(void){

821

int old_errno = errno;

822

int ret = 0;

823

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

824

ret = errno;

825

}

826

errno = old_errno;

827

return ret;

828

}

829

830

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

831

__attribute__((warn_unused_result))

832

int raise_privileges_permanently(void){

833

int old_errno = errno;

834

int ret = raise_privileges();

835

if(ret != 0){

836

errno = old_errno;

837

return ret;

838

}

839

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

840

ret = errno;

841

}

842

errno = old_errno;

843

return ret;

844

}

845

846

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

847

__attribute__((warn_unused_result))

848

int lower_privileges(void){

849

int old_errno = errno;

850

int ret = 0;

851

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

852

ret = errno;

853

}

854

errno = old_errno;

855

return ret;

856

}

857

858

/* Lower privileges permanently */

859

__attribute__((warn_unused_result))

860

int lower_privileges_permanently(void){

861

int old_errno = errno;

862

int ret = 0;

863

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

864

ret = errno;

865

}

866

errno = old_errno;

867

return ret;

868

}

869

870

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

871

__attribute__((nonnull, warn_unused_result))

872

static bool add_delete_local_route(const bool add,

873

const char *address,

874

AvahiIfIndex if_index){

875

int ret;

876

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

877

char add_arg[] = "add";

878

char delete_arg[] = "delete";

879

char debug_flag[] = "--debug";

880

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

881

if(pluginhelperdir == NULL){

882

if(debug){

883

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

884

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

885

}

886

return false;

887

}

888

889

char interface[IF_NAMESIZE];

890

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

891

perror_plus("if_indextoname");

892

return false;

893

}

894

895

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

896

if(devnull == -1){

897

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

898

return false;

899

}

900

pid_t pid = fork();

901

if(pid == 0){

902

/* Child */

903

/* Raise privileges */

904

errno = raise_privileges_permanently();

905

if(errno != 0){

906

perror_plus("Failed to raise privileges");

907

/* _exit(EX_NOPERM); */

908

} else {

909

/* Set group */

910

errno = 0;

911

ret = setgid(0);

912

if(ret == -1){

913

perror_plus("setgid");

914

_exit(EX_NOPERM);

915

}

916

/* Reset supplementary groups */

917

errno = 0;

918

ret = setgroups(0, NULL);

919

if(ret == -1){

920

perror_plus("setgroups");

921

_exit(EX_NOPERM);

922

}

923

}

924

ret = dup2(devnull, STDIN_FILENO);

925

if(ret == -1){

926

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

927

_exit(EX_OSERR);

928

}

929

ret = close(devnull);

930

if(ret == -1){

931

perror_plus("close");

932

_exit(EX_OSERR);

933

}

934

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

935

if(ret == -1){

936

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

937

_exit(EX_OSERR);

938

}

939

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

940

O_RDONLY

941

| O_DIRECTORY

942

| O_PATH

943

| O_CLOEXEC));

944

if(helperdir_fd == -1){

945

perror_plus("open");

946

_exit(EX_UNAVAILABLE);

947

}

948

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

949

helper, O_RDONLY));

950

if(helper_fd == -1){

951

perror_plus("openat");

952

close(helperdir_fd);

953

_exit(EX_UNAVAILABLE);

954

}

955

close(helperdir_fd);

956

#ifdef __GNUC__

957

#pragma GCC diagnostic push

958

#pragma GCC diagnostic ignored "-Wcast-qual"

959

#endif

960

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

961

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

962

interface, debug ? debug_flag : NULL, NULL },

963

environ) == -1){

964

#ifdef __GNUC__

965

#pragma GCC diagnostic pop

966

#endif

967

perror_plus("fexecve");

968

_exit(EXIT_FAILURE);

969

}

970

}

971

if(pid == -1){

972

perror_plus("fork");

973

return false;

974

}

975

int status;

976

pid_t pret = -1;

977

errno = 0;

978

do {

979

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

980

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

981

int errno_raising = 0;

982

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

983

errno_raising = errno;

984

perror_plus("Failed to raise privileges in order to"

985

" kill helper program");

986

}

987

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

988

perror_plus("kill");

989

}

990

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

991

perror_plus("Failed to lower privileges after killing"

992

" helper program");

993

}

994

return false;

995

}

996

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

997

if(pret == -1){

998

perror_plus("waitpid");

999

return false;

1000

}

1001

if(WIFEXITED(status)){

1002

if(WEXITSTATUS(status) != 0){

1003

fprintf_plus(stderr, "Error: iprouteadddel exited"

1004

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

1005

return false;

1006

}

1007

return true;

1008

}

1009

if(WIFSIGNALED(status)){

1010

fprintf_plus(stderr, "Error: iprouteadddel died by"

1011

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

1012

return false;

1013

}

1014

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

1015

return false;

1016

}

1017

1018

__attribute__((nonnull, warn_unused_result))

1019

static bool add_local_route(const char *address,

1020

AvahiIfIndex if_index){

1021

if(debug){

1022

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

1023

}

1024

return add_delete_local_route(true, address, if_index);

1025

}

1026

1027

__attribute__((nonnull, warn_unused_result))

1028

static bool delete_local_route(const char *address,

1029

AvahiIfIndex if_index){

1030

if(debug){

1031

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

1032

}

1033

return add_delete_local_route(false, address, if_index);

1034

}

1035

1036

616

/* Called when a Mandos server is found */

1037

__attribute__((nonnull, warn_unused_result))

1038

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

617

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

1039

618

AvahiIfIndex if_index,

1040

int af, mandos_context *mc){

619

int af){

1041

620

int ret, tcp_sd = -1;

1042

621

ssize_t sret;

1043

struct sockaddr_storage to;

622

union {

623

struct sockaddr_in in;

624

struct sockaddr_in6 in6;

625

} to;

1044

626

char *buffer = NULL;

1045

627

char *decrypted_buffer = NULL;

1046

628

size_t buffer_length = 0;

1049

631

int retval = -1;

1050

632

gnutls_session_t session;

1051

633

int pf; /* Protocol family */

1052

bool route_added = false;

1053

634

1054

635

errno = 0;

1055

636

1071

652

return -1;

1072

653

}

1073

654

1074

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

1075

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

1076

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

1077

bool match = false;

1078

{

1079

char *interface = NULL;

1080

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

1081

interface))){

1082

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

1083

match = true;

1084

break;

1085

}

1086

}

1087

}

1088

if(not match){

1089

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

1090

connect to the server */

1091

if(debug){

1092

char interface[IF_NAMESIZE];

1093

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

1094

perror_plus("if_indextoname");

1095

} else {

1096

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

1097

" \"%s\"\n",

1098

if_indextoname((unsigned int)if_index,

1099

interface));

1100

}

1101

}

1102

return -1;

1103

}

1104

}

1105

1106

ret = init_gnutls_session(&session, mc);

655

ret = init_gnutls_session(&session);

1107

656

if(ret != 0){

1108

657

return -1;

1109

658

}

1110

659

1111

660

if(debug){

1112

661

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

1113

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

662

PRIu16 "\n", ip, port);

1114

663

}

1115

664

1116

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

665

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

666

if(tcp_sd < 0){

1118

667

int e = errno;

1119

668

perror_plus("socket");

1126

675

goto mandos_end;

1127

676

}

1128

677

678

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

1129

679

if(af == AF_INET6){

1130

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

1131

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

1132

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

680

to.in6.sin6_family = (sa_family_t)af;

681

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

1133

682

} else { /* IPv4 */

1134

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

1135

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

1136

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

683

to.in.sin_family = (sa_family_t)af;

684

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

1137

685

}

1138

686

if(ret < 0 ){

1139

687

int e = errno;

1148

696

goto mandos_end;

1149

697

}

1150

698

if(af == AF_INET6){

1151

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

1152

if(IN6_IS_ADDR_LINKLOCAL

1153

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

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*/

1154

706

if(if_index == AVAHI_IF_UNSPEC){

1155

707

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

1156

708

" incomplete without a network interface\n");

1158

710

goto mandos_end;

1159

711

}

1160

712

/* Set the network interface number as scope */

1161

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

713

to.in6.sin6_scope_id = (uint32_t)if_index;

1162

714

}

1163

715

} else {

1164

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

716

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

717

-Wconversion and

718

-Wunreachable-code */

1165

719

}

1166

720

1167

721

if(quit_now){

1175

729

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

1176

730

perror_plus("if_indextoname");

1177

731

} else {

1178

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

1179

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

732

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

733

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

1180

734

}

1181

735

} else {

1182

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

1183

ip, (uintmax_t)port);

736

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

737

ip, port);

1184

738

}

1185

739

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1186

740

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1187

if(af == AF_INET6){

1188

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

1189

sizeof(struct sockaddr_in6),

1190

addrstr, sizeof(addrstr), NULL, 0,

1191

NI_NUMERICHOST);

1192

} else {

1193

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

1194

sizeof(struct sockaddr_in),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

}

1198

if(ret == EAI_SYSTEM){

1199

perror_plus("getnameinfo");

1200

} else if(ret != 0) {

1201

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

1202

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

1203

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

1204

}

1205

}

1206

1207

if(quit_now){

1208

errno = EINTR;

1209

goto mandos_end;

1210

}

1211

1212

while(true){

1213

if(af == AF_INET6){

1214

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

1215

sizeof(struct sockaddr_in6));

1216

} else {

1217

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

1218

sizeof(struct sockaddr_in));

1219

}

1220

if(ret < 0){

1221

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

1222

and if_index != AVAHI_IF_UNSPEC

1223

and connect_to == NULL

1224

and not route_added and

1225

((af == AF_INET6 and not

1226

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1227

&to)->sin6_addr)))

1228

or (af == AF_INET and

1229

/* Not a a IPv4LL address */

1230

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

1231

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

1232

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

1233

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

1234

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

1235

connect to a Mandos server announced by Avahi on a server

1236

host with a global address. Work around this by retrying

1237

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

1238

1239

Avahi bug reference:

1240

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

1241

https://bugs.debian.org/587961

1242

*/

1243

if(debug){

1244

fprintf_plus(stderr, "Mandos server unreachable, trying"

1245

" direct route\n");

1246

}

1247

int e = errno;

1248

route_added = add_local_route(ip, if_index);

1249

if(route_added){

1250

continue;

1251

}

1252

errno = e;

1253

}

1254

if(errno != ECONNREFUSED or debug){

1255

int e = errno;

1256

perror_plus("connect");

1257

errno = e;

1258

}

1259

goto mandos_end;

1260

}

1261

1262

if(quit_now){

1263

errno = EINTR;

1264

goto mandos_end;

1265

}

1266

break;

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;

1267

780

}

1268

781

1269

782

const char *out = mandos_protocol_version;

1305

818

goto mandos_end;

1306

819

}

1307

820

1308

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

1309

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

1310

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

1311

gnutls_transport_set_ptr(session,

1312

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

821

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

822

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1313

823

1314

824

if(quit_now){

1315

825

errno = EINTR;

1420

930

if(buffer_length > 0){

1421

931

ssize_t decrypted_buffer_size;

1422

932

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1423

&decrypted_buffer, mc);

933

&decrypted_buffer);

1424

934

if(decrypted_buffer_size >= 0){

1425

935

1426

936

written = 0;

1452

962

1453

963

mandos_end:

1454

964

{

1455

if(route_added){

1456

if(not delete_local_route(ip, if_index)){

1457

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

1458

" interface %d", ip, if_index);

1459

}

1460

}

1461

965

int e = errno;

1462

966

free(decrypted_buffer);

1463

967

free(buffer);

1464

968

if(tcp_sd >= 0){

1465

ret = close(tcp_sd);

969

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

1466

970

}

1467

971

if(ret == -1){

1468

972

if(e == 0){

1480

984

return retval;

1481

985

}

1482

986

1483

__attribute__((nonnull))

1484

987

static void resolve_callback(AvahiSServiceResolver *r,

1485

988

AvahiIfIndex interface,

1486

989

AvahiProtocol proto,

1494

997

AVAHI_GCC_UNUSED AvahiStringList *txt,

1495

998

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1496

999

flags,

1497

void *mc){

1498

if(r == NULL){

1499

return;

1500

}

1000

AVAHI_GCC_UNUSED void* userdata){

1001

assert(r);

1501

1002

1502

1003

/* Called whenever a service has been resolved successfully or

1503

1004

timed out */

1504

1005

1505

1006

if(quit_now){

1506

avahi_s_service_resolver_free(r);

1507

1007

return;

1508

1008

}

1509

1009

1513

1013

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

1514

1014

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

1515

1015

domain,

1516

avahi_strerror(avahi_server_errno

1517

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

1016

avahi_strerror(avahi_server_errno(mc.server)));

1518

1017

break;

1519

1018

1520

1019

case AVAHI_RESOLVER_FOUND:

1526

1025

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

1527

1026

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

1528

1027

}

1529

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

1530

interface,

1531

avahi_proto_to_af(proto),

1532

mc);

1028

int ret = start_mandos_communication(ip, port, interface,

1029

avahi_proto_to_af(proto));

1533

1030

if(ret == 0){

1534

avahi_simple_poll_quit(simple_poll);

1031

avahi_simple_poll_quit(mc.simple_poll);

1535

1032

} else {

1536

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

1537

avahi_proto_to_af(proto),

1538

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

1539

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

1540

" list\n", name);

1541

}

1033

ret = add_server(ip, port, interface,

1034

avahi_proto_to_af(proto));

1542

1035

}

1543

1036

}

1544

1037

}

1554

1047

const char *domain,

1555

1048

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1556

1049

flags,

1557

void *mc){

1558

if(b == NULL){

1559

return;

1560

}

1050

AVAHI_GCC_UNUSED void* userdata){

1051

assert(b);

1561

1052

1562

1053

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

1563

1054

is removed from the LAN */

1571

1062

case AVAHI_BROWSER_FAILURE:

1572

1063

1573

1064

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

1574

avahi_strerror(avahi_server_errno

1575

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

1576

avahi_simple_poll_quit(simple_poll);

1065

avahi_strerror(avahi_server_errno(mc.server)));

1066

avahi_simple_poll_quit(mc.simple_poll);

1577

1067

return;

1578

1068

1579

1069

case AVAHI_BROWSER_NEW:

1582

1072

the callback function is called the Avahi server will free the

1583

1073

resolver for us. */

1584

1074

1585

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

1586

interface, protocol, name, type,

1587

domain, protocol, 0,

1588

resolve_callback, mc) == NULL)

1075

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

1076

name, type, domain, protocol, 0,

1077

resolve_callback, NULL) == NULL)

1589

1078

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

1590

1079

" %s\n", name,

1591

avahi_strerror(avahi_server_errno

1592

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

1080

avahi_strerror(avahi_server_errno(mc.server)));

1593

1081

break;

1594

1082

1595

1083

case AVAHI_BROWSER_REMOVE:

1614

1102

signal_received = sig;

1615

1103

int old_errno = errno;

1616

1104

/* set main loop to exit */

1617

if(simple_poll != NULL){

1618

avahi_simple_poll_quit(simple_poll);

1105

if(mc.simple_poll != NULL){

1106

avahi_simple_poll_quit(mc.simple_poll);

1619

1107

}

1620

1108

errno = old_errno;

1621

1109

}

1622

1110

1623

__attribute__((nonnull, warn_unused_result))

1624

1111

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

1625

1112

int ret;

1626

int old_errno;

1627

1113

1628

1114

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

1629

1115

if(s < 0){

1630

old_errno = errno;

1631

1116

perror_plus("socket");

1632

errno = old_errno;

1633

1117

return false;

1634

1118

}

1635

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

1636

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

1119

strcpy(ifr->ifr_name, ifname);

1637

1120

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1638

1121

if(ret == -1){

1639

1122

if(debug){

1640

old_errno = errno;

1641

1123

perror_plus("ioctl SIOCGIFFLAGS");

1642

errno = old_errno;

1643

1124

}

1644

1125

return false;

1645

1126

}

1646

1127

return true;

1647

1128

}

1648

1129

1649

__attribute__((nonnull, warn_unused_result))

1650

1130

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

1651

1131

1652

1132

/* Reject the loopback device */

1694

1174

* corresponds to an acceptable network device.

1695

1175

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

1696

1176

*/

1697

__attribute__((nonnull, warn_unused_result))

1698

1177

int good_interface(const struct dirent *if_entry){

1699

1178

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

1700

1179

return 0;

1716

1195

}

1717

1196

1718

1197

/*

1719

* This function determines if a network interface is up.

1720

*/

1721

__attribute__((nonnull, warn_unused_result))

1722

bool interface_is_up(const char *interface){

1723

struct ifreq ifr;

1724

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

1725

if(debug){

1726

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

1727

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

1728

}

1729

return false;

1730

}

1731

1732

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

1733

}

1734

1735

/*

1736

* This function determines if a network interface is running

1737

*/

1738

__attribute__((nonnull, warn_unused_result))

1739

bool interface_is_running(const char *interface){

1740

struct ifreq ifr;

1741

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

1742

if(debug){

1743

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

1744

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

1745

}

1746

return false;

1747

}

1748

1749

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

1750

}

1751

1752

__attribute__((nonnull, pure, warn_unused_result))

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

1753

1240

int notdotentries(const struct dirent *direntry){

1754

1241

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

1755

1242

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

1762

1249

}

1763

1250

1764

1251

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

1765

__attribute__((nonnull, warn_unused_result))

1766

1252

int runnable_hook(const struct dirent *direntry){

1767

1253

int ret;

1768

1254

size_t sret;

1776

1262

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

1777

1263

"abcdefghijklmnopqrstuvwxyz"

1778

1264

"0123456789"

1779

"_.-");

1265

"_-");

1780

1266

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

1781

1267

/* Contains non-allowed characters */

1782

1268

if(debug){

1786

1272

return 0;

1787

1273

}

1788

1274

1789

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

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);

1790

1283

if(ret == -1){

1791

1284

if(debug){

1792

1285

perror_plus("Could not stat hook");

1816

1309

return 1;

1817

1310

}

1818

1311

1819

__attribute__((nonnull, warn_unused_result))

1820

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1821

mandos_context *mc){

1312

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1822

1313

int ret;

1823

1314

struct timespec now;

1824

1315

struct timespec waited_time;

1825

1316

intmax_t block_time;

1826

1317

1827

1318

while(true){

1828

if(mc->current_server == NULL){

1829

if(debug){

1319

if(mc.current_server == NULL){

1320

if (debug){

1830

1321

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

1831

1322

" No timeout!\n");

1832

1323

}

1833

1324

ret = avahi_simple_poll_iterate(s, -1);

1834

1325

} else {

1835

if(debug){

1326

if (debug){

1836

1327

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

1837

1328

" it, or wait\n");

1838

1329

}

1845

1336

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

1846

1337

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

1847

1338

waited_time.tv_sec = (now.tv_sec

1848

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

1339

- mc.current_server->last_seen.tv_sec);

1849

1340

waited_time.tv_nsec = (now.tv_nsec

1850

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

1341

- mc.current_server->last_seen.tv_nsec);

1851

1342

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

1852

1343

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

1853

1344

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

1855

1346

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

1856

1347

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

1857

1348

1858

if(debug){

1349

if (debug){

1859

1350

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

1860

1351

block_time);

1861

1352

}

1862

1353

1863

1354

if(block_time <= 0){

1864

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

1865

mc->current_server->port,

1866

mc->current_server->if_index,

1867

mc->current_server->af, mc);

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);

1868

1359

if(ret == 0){

1869

avahi_simple_poll_quit(s);

1360

avahi_simple_poll_quit(mc.simple_poll);

1870

1361

return 0;

1871

1362

}

1872

1363

ret = clock_gettime(CLOCK_MONOTONIC,

1873

&mc->current_server->last_seen);

1364

&mc.current_server->last_seen);

1874

1365

if(ret == -1){

1875

1366

perror_plus("clock_gettime");

1876

1367

return -1;

1877

1368

}

1878

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

1369

mc.current_server = mc.current_server->next;

1879

1370

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

1880

1371

servers, but don't block */

1881

1372

}

1883

1374

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

1884

1375

}

1885

1376

if(ret != 0){

1886

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

1377

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

1887

1378

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

1888

1379

}

1889

1380

}

1890

1381

}

1891

1382

}

1892

1383

1893

__attribute__((nonnull))

1894

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

1384

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

1895

1385

const float delay){

1896

struct dirent **direntries = NULL;

1897

if(hookdir_fd == -1){

1898

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1899

| O_CLOEXEC);

1900

if(hookdir_fd == -1){

1901

if(errno == ENOENT){

1902

if(debug){

1903

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

1904

" found\n", hookdir);

1905

}

1906

} else {

1907

perror_plus("open");

1908

}

1909

return;

1910

}

1911

}

1912

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

1913

runnable_hook, alphasort);

1386

struct dirent **direntries;

1387

struct dirent *direntry;

1388

int ret;

1389

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

1390

alphasort);

1914

1391

if(numhooks == -1){

1915

1392

perror_plus("scandir");

1916

return;

1917

}

1918

struct dirent *direntry;

1919

int ret;

1920

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

1921

if(devnull == -1){

1922

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

1923

return;

1924

}

1925

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

1926

direntry = direntries[i];

1927

if(debug){

1928

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

1929

direntry->d_name);

1930

}

1931

pid_t hook_pid = fork();

1932

if(hook_pid == 0){

1933

/* Child */

1934

/* Raise privileges */

1935

errno = raise_privileges_permanently();

1936

if(errno != 0){

1937

perror_plus("Failed to raise privileges");

1938

_exit(EX_NOPERM);

1939

}

1940

/* Set group */

1941

errno = 0;

1942

ret = setgid(0);

1943

if(ret == -1){

1944

perror_plus("setgid");

1945

_exit(EX_NOPERM);

1946

}

1947

/* Reset supplementary groups */

1948

errno = 0;

1949

ret = setgroups(0, NULL);

1950

if(ret == -1){

1951

perror_plus("setgroups");

1952

_exit(EX_NOPERM);

1953

}

1954

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

1955

if(ret == -1){

1956

perror_plus("setenv");

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("setenv");

1962

_exit(EX_OSERR);

1963

}

1964

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

1965

if(ret == -1){

1966

perror_plus("setenv");

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

if(ret == -1){

1971

perror_plus("setenv");

1972

_exit(EX_OSERR);

1973

}

1974

char *delaystring;

1975

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

1976

if(ret == -1){

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){

1977

1400

perror_plus("asprintf");

1978

_exit(EX_OSERR);

1979

}

1980

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

1981

if(ret == -1){

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

dup2(devnull, STDIN_FILENO);

1435

close(devnull);

1436

dup2(STDERR_FILENO, STDOUT_FILENO);

1437

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

1438

if(ret == -1){

1439

perror_plus("setenv");

1440

_exit(EX_OSERR);

1441

}

1442

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

1443

if(ret == -1){

1444

perror_plus("setenv");

1445

_exit(EX_OSERR);

1446

}

1447

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

1448

if(ret == -1){

1449

perror_plus("setenv");

1450

_exit(EX_OSERR);

1451

}

1452

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

1453

if(ret == -1){

1454

perror_plus("setenv");

1455

_exit(EX_OSERR);

1456

}

1457

char *delaystring;

1458

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

1459

if(ret == -1){

1460

perror_plus("asprintf");

1461

_exit(EX_OSERR);

1462

}

1463

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

1464

if(ret == -1){

1465

free(delaystring);

1466

perror_plus("setenv");

1467

_exit(EX_OSERR);

1468

}

1982

1469

free(delaystring);

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

free(delaystring);

1987

if(connect_to != NULL){

1988

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

1989

if(ret == -1){

1990

perror_plus("setenv");

1991

_exit(EX_OSERR);

1992

}

1993

}

1994

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

1995

direntry->d_name,

1996

O_RDONLY));

1997

if(hook_fd == -1){

1998

perror_plus("openat");

1999

_exit(EXIT_FAILURE);

2000

}

2001

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

2002

perror_plus("close");

2003

_exit(EXIT_FAILURE);

2004

}

2005

ret = dup2(devnull, STDIN_FILENO);

2006

if(ret == -1){

2007

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

2008

_exit(EX_OSERR);

2009

}

2010

ret = close(devnull);

2011

if(ret == -1){

2012

perror_plus("close");

2013

_exit(EX_OSERR);

2014

}

2015

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2016

if(ret == -1){

2017

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

2018

_exit(EX_OSERR);

2019

}

2020

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

2021

environ) == -1){

2022

perror_plus("fexecve");

2023

_exit(EXIT_FAILURE);

2024

}

2025

} else {

2026

if(hook_pid == -1){

2027

perror_plus("fork");

2028

free(direntry);

2029

continue;

2030

}

2031

int status;

2032

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

2033

perror_plus("waitpid");

2034

free(direntry);

2035

continue;

2036

}

2037

if(WIFEXITED(status)){

2038

if(WEXITSTATUS(status) != 0){

2039

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

2040

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

2041

WEXITSTATUS(status));

2042

free(direntry);

2043

continue;

2044

}

2045

} else if(WIFSIGNALED(status)){

2046

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

2047

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

2048

WTERMSIG(status));

2049

free(direntry);

2050

continue;

2051

} else {

2052

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

2053

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

2054

free(direntry);

2055

continue;

2056

}

2057

}

2058

if(debug){

2059

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

2060

direntry->d_name);

2061

}

2062

free(direntry);

2063

}

2064

free(direntries);

2065

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

2066

perror_plus("close");

2067

} else {

2068

hookdir_fd = -1;

2069

}

2070

close(devnull);

2071

}

2072

2073

__attribute__((nonnull, warn_unused_result))

2074

int bring_up_interface(const char *const interface,

2075

const float delay){

2076

int old_errno = errno;

2077

int ret;

2078

struct ifreq network;

2079

unsigned int if_index = if_nametoindex(interface);

2080

if(if_index == 0){

2081

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

2082

errno = old_errno;

2083

return ENXIO;

2084

}

2085

2086

if(quit_now){

2087

errno = old_errno;

2088

return EINTR;

2089

}

2090

2091

if(not interface_is_up(interface)){

2092

int ret_errno = 0;

2093

int ioctl_errno = 0;

2094

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

2095

ret_errno = errno;

2096

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

2097

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

2098

errno = old_errno;

2099

return ret_errno;

2100

}

2101

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

2102

2103

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

2104

if(sd == -1){

2105

ret_errno = errno;

2106

perror_plus("socket");

2107

errno = old_errno;

2108

return ret_errno;

2109

}

2110

2111

if(quit_now){

2112

ret = close(sd);

2113

if(ret == -1){

2114

perror_plus("close");

2115

}

2116

errno = old_errno;

2117

return EINTR;

2118

}

2119

2120

if(debug){

2121

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

2122

interface);

2123

}

2124

2125

/* Raise privileges */

2126

ret_errno = raise_privileges();

2127

if(ret_errno != 0){

2128

errno = ret_errno;

2129

perror_plus("Failed to raise privileges");

2130

}

2131

2132

#ifdef __linux__

2133

int ret_linux;

2134

bool restore_loglevel = false;

2135

if(ret_errno == 0){

2136

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2137

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

2138

ret_linux = klogctl(8, NULL, 5);

2139

if(ret_linux == -1){

2140

perror_plus("klogctl");

2141

} else {

2142

restore_loglevel = true;

2143

}

2144

}

2145

#endif /* __linux__ */

2146

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

2147

ioctl_errno = errno;

2148

#ifdef __linux__

2149

if(restore_loglevel){

2150

ret_linux = klogctl(7, NULL, 0);

2151

if(ret_linux == -1){

2152

perror_plus("klogctl");

2153

}

2154

}

2155

#endif /* __linux__ */

2156

2157

/* If raise_privileges() succeeded above */

2158

if(ret_errno == 0){

2159

/* Lower privileges */

2160

ret_errno = lower_privileges();

2161

if(ret_errno != 0){

2162

errno = ret_errno;

2163

perror_plus("Failed to lower privileges");

2164

}

2165

}

2166

2167

/* Close the socket */

2168

ret = close(sd);

2169

if(ret == -1){

2170

perror_plus("close");

2171

}

2172

2173

if(ret_setflags == -1){

2174

errno = ioctl_errno;

2175

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2176

errno = old_errno;

2177

return ioctl_errno;

2178

}

2179

} else if(debug){

2180

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

2181

interface);

2182

}

2183

2184

/* Sleep checking until interface is running.

2185

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

2186

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

2187

if(interface_is_running(interface)){

2188

break;

2189

}

2190

struct timespec sleeptime = { .tv_nsec = 250000000 };

2191

ret = nanosleep(&sleeptime, NULL);

2192

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

2193

perror_plus("nanosleep");

2194

}

2195

}

2196

2197

errno = old_errno;

2198

return 0;

2199

}

2200

2201

__attribute__((nonnull, warn_unused_result))

2202

int take_down_interface(const char *const interface){

2203

int old_errno = errno;

2204

struct ifreq network;

2205

unsigned int if_index = if_nametoindex(interface);

2206

if(if_index == 0){

2207

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

2208

errno = old_errno;

2209

return ENXIO;

2210

}

2211

if(interface_is_up(interface)){

2212

int ret_errno = 0;

2213

int ioctl_errno = 0;

2214

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

2215

ret_errno = errno;

2216

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

2217

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

2218

errno = old_errno;

2219

return ret_errno;

2220

}

2221

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

2222

2223

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

2224

if(sd == -1){

2225

ret_errno = errno;

2226

perror_plus("socket");

2227

errno = old_errno;

2228

return ret_errno;

2229

}

2230

2231

if(debug){

2232

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

2233

interface);

2234

}

2235

2236

/* Raise privileges */

2237

ret_errno = raise_privileges();

2238

if(ret_errno != 0){

2239

errno = ret_errno;

2240

perror_plus("Failed to raise privileges");

2241

}

2242

2243

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

2244

ioctl_errno = errno;

2245

2246

/* If raise_privileges() succeeded above */

2247

if(ret_errno == 0){

2248

/* Lower privileges */

2249

ret_errno = lower_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to lower privileges");

2253

}

2254

}

2255

2256

/* Close the socket */

2257

int ret = close(sd);

2258

if(ret == -1){

2259

perror_plus("close");

2260

}

2261

2262

if(ret_setflags == -1){

2263

errno = ioctl_errno;

2264

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2265

errno = old_errno;

2266

return ioctl_errno;

2267

}

2268

} else if(debug){

2269

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

2270

interface);

2271

}

2272

2273

errno = old_errno;

2274

return 0;

1470

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

1471

perror_plus("execl");

1472

} else {

1473

int status;

1474

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

1475

perror_plus("waitpid");

1476

free(fullname);

1477

continue;

1478

}

1479

if(WIFEXITED(status)){

1480

if(WEXITSTATUS(status) != 0){

1481

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

1482

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

1483

WEXITSTATUS(status));

1484

free(fullname);

1485

continue;

1486

}

1487

} else if(WIFSIGNALED(status)){

1488

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

1489

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

1490

WTERMSIG(status));

1491

free(fullname);

1492

continue;

1493

} else {

1494

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

1495

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

1496

free(fullname);

1497

continue;

1498

}

1499

}

1500

free(fullname);

1501

if(debug){

1502

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

1503

direntry->d_name);

1504

}

1505

}

1506

close(devnull);

1507

}

1508

return true;

2275

1509

}

2276

1510

2277

1511

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

2278

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

2279

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

2280

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

2281

.current_server = NULL, .interfaces = NULL,

2282

.interfaces_size = 0 };

2283

1512

AvahiSServiceBrowser *sb = NULL;

2284

error_t ret_errno;

1513

int error;

2285

1514

int ret;

2286

1515

intmax_t tmpmax;

2287

1516

char *tmp;

2288

1517

int exitcode = EXIT_SUCCESS;

2289

char *interfaces_to_take_down = NULL;

2290

size_t interfaces_to_take_down_size = 0;

2291

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

2292

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

2293

char *tempdir = NULL;

1518

const char *interface = "";

1519

struct ifreq network;

1520

int sd = -1;

1521

bool take_down_interface = false;

1522

uid_t uid;

1523

gid_t gid;

1524

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

1525

bool tempdir_created = false;

2294

1526

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2295

1527

const char *seckey = PATHDIR "/" SECKEY;

2296

1528

const char *pubkey = PATHDIR "/" PUBKEY;

2297

const char *dh_params_file = NULL;

2298

char *interfaces_hooks = NULL;

2299

1529

2300

1530

bool gnutls_initialized = false;

2301

1531

bool gpgme_initialized = false;

2353

1583

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

2354

1584

" Diffie-Hellman key exchange",

2355

1585

.group = 2 },

2356

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

2357

.arg = "FILE",

2358

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

2359

" for the Diffie-Hellman key exchange",

2360

.group = 2 },

2361

1586

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

2362

1587

.arg = "STRING",

2363

1588

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

2368

1593

.group = 2 },

2369

1594

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

2370

1595

.arg = "SECONDS",

2371

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

1596

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

2372

1597

.group = 2 },

2373

1598

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

2374

1599

.arg = "DIR",

2397

1622

connect_to = arg;

2398

1623

break;

2399

1624

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

2400

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

2401

arg, (int)',');

2402

if(ret_errno != 0){

2403

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

2404

}

1625

interface = arg;

2405

1626

break;

2406

1627

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

2407

1628

seckey = arg;

2418

1639

}

2419

1640

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

2420

1641

break;

2421

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

2422

dh_params_file = arg;

2423

break;

2424

1642

case 130: /* --priority */

2425

1643

mc.priority = arg;

2426

1644

break;

2453

1671

argp_state_help(state, state->out_stream,

2454

1672

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

2455

1673

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

1674

fprintf_plus(state->out_stream,

1675

"Mandos plugin mandos-client: ");

2456

1676

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

2457

1677

exit(argp_err_exit_status);

2458

1678

break;

2466

1686

.args_doc = "",

2467

1687

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

2468

1688

" passwords from a Mandos server" };

2469

ret_errno = argp_parse(&argp, argc, argv,

2470

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2471

switch(ret_errno){

1689

ret = argp_parse(&argp, argc, argv,

1690

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1691

switch(ret){

2472

1692

case 0:

2473

1693

break;

2474

1694

case ENOMEM:

2475

1695

default:

2476

errno = ret_errno;

1696

errno = ret;

2477

1697

perror_plus("argp_parse");

2478

1698

exitcode = EX_OSERR;

2479

1699

goto end;

2482

1702

goto end;

2483

1703

}

2484

1704

}

2485

1705

2486

1706

{

2487

1707

/* Work around Debian bug #633582:

2488

1708

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

2489

1709

2490

/* Re-raise privileges */

2491

ret = raise_privileges();

2492

if(ret != 0){

2493

errno = ret;

2494

perror_plus("Failed to raise privileges");

1710

/* Re-raise priviliges */

1711

errno = 0;

1712

ret = seteuid(0);

1713

if(ret == -1){

1714

perror_plus("seteuid");

2495

1715

} else {

2496

1716

struct stat st;

2497

1717

2512

1732

}

2513

1733

}

2514

1734

}

2515

close(seckey_fd);

1735

TEMP_FAILURE_RETRY(close(seckey_fd));

2516

1736

}

2517

1737

}

2518

1738

2519

1739

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

2520

1740

int pubkey_fd = open(pubkey, O_RDONLY);

2521

1741

if(pubkey_fd == -1){

2533

1753

}

2534

1754

}

2535

1755

}

2536

close(pubkey_fd);

2537

}

2538

}

2539

2540

if(dh_params_file != NULL

2541

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

2542

int dhparams_fd = open(dh_params_file, O_RDONLY);

2543

if(dhparams_fd == -1){

2544

perror_plus("open");

2545

} else {

2546

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

2547

if(ret == -1){

2548

perror_plus("fstat");

2549

} else {

2550

if(S_ISREG(st.st_mode)

2551

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

2552

ret = fchown(dhparams_fd, uid, gid);

2553

if(ret == -1){

2554

perror_plus("fchown");

2555

}

2556

}

2557

}

2558

close(dhparams_fd);

2559

}

2560

}

2561

1756

TEMP_FAILURE_RETRY(close(pubkey_fd));

1757

}

1758

}

1759

2562

1760

/* Lower privileges */

2563

ret = lower_privileges();

2564

if(ret != 0){

2565

errno = ret;

2566

perror_plus("Failed to lower privileges");

2567

}

2568

}

2569

}

2570

2571

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

2572

{

2573

char *interface = NULL;

2574

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

2575

interface))){

2576

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

2577

and if_nametoindex(interface) == 0){

2578

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

2579

fprintf_plus(stderr, "Not using nonexisting interface"

2580

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

2581

}

2582

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

2583

interface = NULL;

1761

errno = 0;

1762

ret = seteuid(uid);

1763

if(ret == -1){

1764

perror_plus("seteuid");

2584

1765

}

2585

1766

}

2586

1767

}

2587

1768

2588

1769

/* Run network hooks */

2589

{

2590

if(mc.interfaces != NULL){

2591

interfaces_hooks = malloc(mc.interfaces_size);

2592

if(interfaces_hooks == NULL){

2593

perror_plus("malloc");

2594

goto end;

2595

}

2596

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

2597

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

2598

}

2599

run_network_hooks("start", interfaces_hooks != NULL ?

2600

interfaces_hooks : "", delay);

1770

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

1771

goto end;

2601

1772

}

2602

1773

2603

1774

if(not debug){

2604

1775

avahi_set_log_function(empty_log);

2605

1776

}

2606

1777

1778

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

1779

struct dirent **direntries;

1780

/* First look for interfaces that are up */

1781

ret = scandir(sys_class_net, &direntries, up_interface,

1782

alphasort);

1783

if(ret == 0){

1784

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

1785

free(direntries);

1786

ret = scandir(sys_class_net, &direntries, good_interface,

1787

alphasort);

1788

}

1789

if(ret >= 1){

1790

/* Pick the first interface returned */

1791

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

1792

if(debug){

1793

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

1794

}

1795

if(interface == NULL){

1796

perror_plus("malloc");

1797

free(direntries);

1798

exitcode = EXIT_FAILURE;

1799

goto end;

1800

}

1801

free(direntries);

1802

} else {

1803

free(direntries);

1804

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

1805

exitcode = EXIT_FAILURE;

1806

goto end;

1807

}

1808

}

1809

2607

1810

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

2608

1811

from the signal handler */

2609

1812

/* Initialize the pseudo-RNG for Avahi */

2610

1813

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

2611

simple_poll = avahi_simple_poll_new();

2612

if(simple_poll == NULL){

1814

mc.simple_poll = avahi_simple_poll_new();

1815

if(mc.simple_poll == NULL){

2613

1816

fprintf_plus(stderr,

2614

1817

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

2615

1818

exitcode = EX_UNAVAILABLE;

2679

1882

}

2680

1883

}

2681

1884

2682

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

2683

if(mc.interfaces == NULL){

2684

struct dirent **direntries = NULL;

2685

/* Look for any good interfaces */

2686

ret = scandir(sys_class_net, &direntries, good_interface,

2687

alphasort);

2688

if(ret >= 1){

2689

/* Add all found interfaces to interfaces list */

2690

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

2691

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

2692

direntries[i]->d_name);

2693

if(ret_errno != 0){

2694

errno = ret_errno;

2695

perror_plus("argz_add");

2696

free(direntries[i]);

2697

continue;

2698

}

2699

if(debug){

2700

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

2701

direntries[i]->d_name);

2702

}

2703

free(direntries[i]);

2704

}

2705

free(direntries);

2706

} else {

2707

if(ret == 0){

2708

free(direntries);

2709

}

2710

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

2711

exitcode = EXIT_FAILURE;

2712

goto end;

2713

}

2714

}

2715

2716

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

2717

{

2718

char *interface = NULL;

2719

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

2720

interface))){

2721

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

2722

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

2723

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

2724

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

2725

interface);

2726

interface = NULL;

2727

while((interface = argz_next(mc.interfaces,

2728

mc.interfaces_size, interface))){

2729

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

2730

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

2731

interface);

2732

interface = NULL;

1885

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

1886

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

1887

if_index = (AvahiIfIndex) if_nametoindex(interface);

1888

if(if_index == 0){

1889

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

1890

exitcode = EX_UNAVAILABLE;

1891

goto end;

1892

}

1893

1894

if(quit_now){

1895

goto end;

1896

}

1897

1898

/* Re-raise priviliges */

1899

errno = 0;

1900

ret = seteuid(0);

1901

if(ret == -1){

1902

perror_plus("seteuid");

1903

}

1904

1905

#ifdef __linux__

1906

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1907

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

1908

ret = klogctl(8, NULL, 5);

1909

bool restore_loglevel = true;

1910

if(ret == -1){

1911

restore_loglevel = false;

1912

perror_plus("klogctl");

1913

}

1914

#endif /* __linux__ */

1915

1916

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1917

if(sd < 0){

1918

perror_plus("socket");

1919

exitcode = EX_OSERR;

1920

#ifdef __linux__

1921

if(restore_loglevel){

1922

ret = klogctl(7, NULL, 0);

1923

if(ret == -1){

1924

perror_plus("klogctl");

1925

}

1926

}

1927

#endif /* __linux__ */

1928

/* Lower privileges */

1929

errno = 0;

1930

ret = seteuid(uid);

1931

if(ret == -1){

1932

perror_plus("seteuid");

1933

}

1934

goto end;

1935

}

1936

strcpy(network.ifr_name, interface);

1937

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

1938

if(ret == -1){

1939

perror_plus("ioctl SIOCGIFFLAGS");

1940

#ifdef __linux__

1941

if(restore_loglevel){

1942

ret = klogctl(7, NULL, 0);

1943

if(ret == -1){

1944

perror_plus("klogctl");

1945

}

1946

}

1947

#endif /* __linux__ */

1948

exitcode = EX_OSERR;

1949

/* Lower privileges */

1950

errno = 0;

1951

ret = seteuid(uid);

1952

if(ret == -1){

1953

perror_plus("seteuid");

1954

}

1955

goto end;

1956

}

1957

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

1958

network.ifr_flags |= IFF_UP;

1959

take_down_interface = true;

1960

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

1961

if(ret == -1){

1962

take_down_interface = false;

1963

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1964

exitcode = EX_OSERR;

1965

#ifdef __linux__

1966

if(restore_loglevel){

1967

ret = klogctl(7, NULL, 0);

1968

if(ret == -1){

1969

perror_plus("klogctl");

2733

1970

}

2734

1971

}

1972

#endif /* __linux__ */

1973

/* Lower privileges */

1974

errno = 0;

1975

ret = seteuid(uid);

1976

if(ret == -1){

1977

perror_plus("seteuid");

1978

}

1979

goto end;

1980

}

1981

}

1982

/* Sleep checking until interface is running.

1983

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

1984

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

1985

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

1986

if(ret == -1){

1987

perror_plus("ioctl SIOCGIFFLAGS");

1988

} else if(network.ifr_flags & IFF_RUNNING){

2735

1989

break;

2736

1990

}

2737

bool interface_was_up = interface_is_up(interface);

2738

errno = bring_up_interface(interface, delay);

2739

if(not interface_was_up){

2740

if(errno != 0){

2741

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

2742

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

2743

} else {

2744

errno = argz_add(&interfaces_to_take_down,

2745

&interfaces_to_take_down_size,

2746

interface);

2747

if(errno != 0){

2748

perror_plus("argz_add");

2749

}

2750

}

2751

}

2752

}

2753

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

2754

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

2755

}

2756

}

2757

2758

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

2759

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

2760

if(debug){

2761

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

2762

mc.interfaces);

2763

}

2764

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

1991

struct timespec sleeptime = { .tv_nsec = 250000000 };

1992

ret = nanosleep(&sleeptime, NULL);

1993

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

1994

perror_plus("nanosleep");

1995

}

1996

}

1997

if(not take_down_interface){

1998

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

1999

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

2000

if(ret == -1){

2001

perror_plus("close");

2002

}

2003

}

2004

#ifdef __linux__

2005

if(restore_loglevel){

2006

/* Restores kernel loglevel to default */

2007

ret = klogctl(7, NULL, 0);

2008

if(ret == -1){

2009

perror_plus("klogctl");

2010

}

2011

}

2012

#endif /* __linux__ */

2013

/* Lower privileges */

2014

errno = 0;

2015

/* Lower privileges */

2016

ret = seteuid(uid);

2017

if(ret == -1){

2018

perror_plus("seteuid");

2019

}

2765

2020

}

2766

2021

2767

2022

if(quit_now){

2768

2023

goto end;

2769

2024

}

2770

2025

2771

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

2026

ret = init_gnutls_global(pubkey, seckey);

2772

2027

if(ret == -1){

2773

2028

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

2774

2029

exitcode = EX_UNAVAILABLE;

2781

2036

goto end;

2782

2037

}

2783

2038

2784

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

2785

tempdir = mkdtemp(run_tempdir);

2786

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

2787

if(debug){

2788

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

2789

run_tempdir, old_tempdir);

2790

}

2791

tempdir = mkdtemp(old_tempdir);

2792

}

2793

if(tempdir == NULL){

2039

if(mkdtemp(tempdir) == NULL){

2794

2040

perror_plus("mkdtemp");

2795

2041

goto end;

2796

2042

}

2043

tempdir_created = true;

2797

2044

2798

2045

if(quit_now){

2799

2046

goto end;

2800

2047

}

2801

2048

2802

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

2049

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

2803

2050

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

2804

2051

exitcode = EX_UNAVAILABLE;

2805

2052

goto end;

2815

2062

/* Connect directly, do not use Zeroconf */

2816

2063

/* (Mainly meant for debugging) */

2817

2064

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

2818

2819

2065

if(address == NULL){

2820

2066

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

2821

2067

exitcode = EX_USAGE;

2826

2072

goto end;

2827

2073

}

2828

2074

2829

in_port_t port;

2075

uint16_t port;

2830

2076

errno = 0;

2831

2077

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

2832

2078

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

2833

or tmpmax != (in_port_t)tmpmax){

2079

or tmpmax != (uint16_t)tmpmax){

2834

2080

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

2835

2081

exitcode = EX_USAGE;

2836

2082

goto end;

2837

2083

}

2838

2084

2839

2085

if(quit_now){

2840

2086

goto end;

2841

2087

}

2842

2088

2843

port = (in_port_t)tmpmax;

2089

port = (uint16_t)tmpmax;

2844

2090

*address = '\0';

2845

2091

/* Colon in address indicates IPv6 */

2846

2092

int af;

2862

2108

}

2863

2109

2864

2110

while(not quit_now){

2865

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

2866

&mc);

2111

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

2867

2112

if(quit_now or ret == 0){

2868

2113

break;

2869

2114

}

2871

2116

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

2872

2117

(int)retry_interval);

2873

2118

}

2874

sleep((unsigned int)retry_interval);

2119

sleep((int)retry_interval);

2875

2120

}

2876

2121

2877

if(not quit_now){

2122

if (not quit_now){

2878

2123

exitcode = EXIT_SUCCESS;

2879

2124

}

2880

2125

2895

2140

config.publish_domain = 0;

2896

2141

2897

2142

/* Allocate a new server */

2898

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2899

&config, NULL, NULL, &ret);

2143

mc.server = avahi_server_new(avahi_simple_poll_get

2144

(mc.simple_poll), &config, NULL,

2145

NULL, &error);

2900

2146

2901

2147

/* Free the Avahi configuration data */

2902

2148

avahi_server_config_free(&config);

2905

2151

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

2906

2152

if(mc.server == NULL){

2907

2153

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

2908

avahi_strerror(ret));

2154

avahi_strerror(error));

2909

2155

exitcode = EX_UNAVAILABLE;

2910

2156

goto end;

2911

2157

}

2917

2163

/* Create the Avahi service browser */

2918

2164

sb = avahi_s_service_browser_new(mc.server, if_index,

2919

2165

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2920

NULL, 0, browse_callback,

2921

(void *)&mc);

2166

NULL, 0, browse_callback, NULL);

2922

2167

if(sb == NULL){

2923

2168

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

2924

2169

avahi_strerror(avahi_server_errno(mc.server)));

2935

2180

if(debug){

2936

2181

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

2937

2182

}

2938

2939

ret = avahi_loop_with_timeout(simple_poll,

2940

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

2183

2184

ret = avahi_loop_with_timeout(mc.simple_poll,

2185

(int)(retry_interval * 1000));

2941

2186

if(debug){

2942

2187

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

2943

2188

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

2950

2195

}

2951

2196

2952

2197

/* Cleanup things */

2953

free(mc.interfaces);

2954

2955

2198

if(sb != NULL)

2956

2199

avahi_s_service_browser_free(sb);

2957

2200

2958

2201

if(mc.server != NULL)

2959

2202

avahi_server_free(mc.server);

2960

2203

2961

if(simple_poll != NULL)

2962

avahi_simple_poll_free(simple_poll);

2204

if(mc.simple_poll != NULL)

2205

avahi_simple_poll_free(mc.simple_poll);

2963

2206

2964

2207

if(gnutls_initialized){

2965

2208

gnutls_certificate_free_credentials(mc.cred);

2209

gnutls_global_deinit();

2966

2210

gnutls_dh_params_deinit(mc.dh_params);

2967

2211

}

2968

2212

2976

2220

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

2977

2221

while(mc.current_server != NULL){

2978

2222

server *next = mc.current_server->next;

2979

#ifdef __GNUC__

2980

#pragma GCC diagnostic push

2981

#pragma GCC diagnostic ignored "-Wcast-qual"

2982

#endif

2983

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

2984

#ifdef __GNUC__

2985

#pragma GCC diagnostic pop

2986

#endif

2987

2223

free(mc.current_server);

2988

2224

mc.current_server = next;

2989

2225

}

2990

2226

}

2991

2227

2992

/* Re-raise privileges */

2228

/* Run network hooks */

2229

run_network_hooks("stop", interface, delay);

2230

2231

/* Re-raise priviliges */

2993

2232

{

2994

ret = raise_privileges();

2995

if(ret != 0){

2996

errno = ret;

2997

perror_plus("Failed to raise privileges");

2998

} else {

2999

3000

/* Run network hooks */

3001

run_network_hooks("stop", interfaces_hooks != NULL ?

3002

interfaces_hooks : "", delay);

3003

3004

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

3005

{

3006

char *interface = NULL;

3007

while((interface=argz_next(interfaces_to_take_down,

3008

interfaces_to_take_down_size,

3009

interface))){

3010

ret = take_down_interface(interface);

3011

if(ret != 0){

3012

errno = ret;

3013

perror_plus("Failed to take down interface");

3014

}

3015

}

3016

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

3017

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

3018

" down\n");

3019

}

3020

}

2233

errno = 0;

2234

ret = seteuid(0);

2235

if(ret == -1){

2236

perror_plus("seteuid");

3021

2237

}

3022

2238

3023

ret = lower_privileges_permanently();

3024

if(ret != 0){

3025

errno = ret;

3026

perror_plus("Failed to lower privileges permanently");

2239

/* Take down the network interface */

2240

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

2241

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

2242

if(ret == -1){

2243

perror_plus("ioctl SIOCGIFFLAGS");

2244

} else if(network.ifr_flags & IFF_UP){

2245

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

2246

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

2247

if(ret == -1){

2248

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2249

}

2250

}

2251

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

2252

if(ret == -1){

2253

perror_plus("close");

2254

}

3027

2255

}

3028

2256

}

3029

3030

free(interfaces_to_take_down);

3031

free(interfaces_hooks);

3032

3033

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

3034

uintmax_t level){

2257

/* Lower privileges permanently */

2258

errno = 0;

2259

ret = setuid(uid);

2260

if(ret == -1){

2261

perror_plus("setuid");

2262

}

2263

2264

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

2265

if(tempdir_created){

3035

2266

struct dirent **direntries = NULL;

3036

int dret;

3037

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

3038

O_RDONLY

3039

| O_NOFOLLOW

3040

| O_DIRECTORY

3041

| O_PATH));

3042

if(dir_fd == -1){

3043

perror_plus("open");

3044

}

3045

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

3046

notdotentries, alphasort);

3047

if(numentries >= 0){

2267

struct dirent *direntry = NULL;

2268

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

2269

alphasort);

2270

if (numentries > 0){

3048

2271

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

3049

if(debug){

3050

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

3051

dirname, direntries[i]->d_name);

3052

}

3053

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

3054

if(dret == -1){

3055

if(errno == EISDIR){

3056

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

3057

AT_REMOVEDIR);

3058

}

3059

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

3060

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

3061

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

3062

/* Recurse only in this special case */

3063

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

3064

dret = 0;

3065

}

3066

if(dret == -1){

3067

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

3068

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

3069

}

3070

}

3071

free(direntries[i]);

3072

}

3073

3074

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

3075

free(direntries);

3076

if(numentries == -1){

3077

perror_plus("scandirat");

3078

}

3079

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3080

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

3081

perror_plus("rmdir");

3082

}

3083

} else {

3084

perror_plus("scandirat");

3085

}

3086

close(dir_fd);

3087

}

3088

3089

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

3090

if(tempdir != NULL){

3091

clean_dir_at(-1, tempdir, 0);

2272

direntry = direntries[i];

2273

char *fullname = NULL;

2274

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

2275

direntry->d_name);

2276

if(ret < 0){

2277

perror_plus("asprintf");

2278

continue;

2279

}

2280

ret = remove(fullname);

2281

if(ret == -1){

2282

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

2283

strerror(errno));

2284

}

2285

free(fullname);

2286

}

2287

}

2288

2289

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

2290

free(direntries);

2291

if (numentries == -1){

2292

perror_plus("scandir");

2293

}

2294

ret = rmdir(tempdir);

2295

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

2296

perror_plus("rmdir");

2297

}

3092

2298

}

3093

2299

3094

2300

if(quit_now){