/mandos/trunk : revision 535.1.8

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

10

*

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* Everything else is

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13

12

13

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*

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

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

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 */

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#endif

39

40

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

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

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stdout, ferror() */

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 */

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

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

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strtof(), abort() */

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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() */

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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() */

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

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inet_pton(), connect() */

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

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

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61

*/

64

62

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

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63

strtoimax() */

66

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

64

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

65

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

71

66

program_invocation_short_name */

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

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

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unlinkat() */

83

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

76

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

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

84

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

85

79

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

86

80

argp_state, struct argp,

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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

} while(false);

630

}

631

if(dhparamsfilename == NULL){

632

if(mc->dh_bits == 0){

633

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

634

/* Try to read the private key file */

635

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

636

do {

637

int secfile = open(seckeyfilename, O_RDONLY);

638

if(secfile == -1){

639

perror_plus("open");

640

break;

641

}

642

size_t buffer_capacity = 0;

643

while(true){

644

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

645

(size_t)buffer.size,

646

(size_t)buffer_capacity);

647

if(buffer_capacity == 0){

648

perror_plus("incbuffer");

649

free(buffer.data);

650

buffer.data = NULL;

651

break;

652

}

653

ssize_t bytes_read = read(secfile,

654

buffer.data + buffer.size,

655

BUFFER_SIZE);

656

/* EOF */

657

if(bytes_read == 0){

658

break;

659

}

660

/* check bytes_read for failure */

661

if(bytes_read < 0){

662

perror_plus("read");

663

free(buffer.data);

664

buffer.data = NULL;

665

break;

666

}

667

buffer.size += (unsigned int)bytes_read;

668

}

669

close(secfile);

670

} while(false);

671

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

672

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

673

if(buffer.data != NULL){

674

{

675

gnutls_openpgp_privkey_t privkey = NULL;

676

ret = gnutls_openpgp_privkey_init(&privkey);

677

if(ret != GNUTLS_E_SUCCESS){

678

fprintf_plus(stderr, "Error initializing OpenPGP key"

679

" structure: %s",

680

safer_gnutls_strerror(ret));

681

free(buffer.data);

682

buffer.data = NULL;

683

} else {

684

ret = gnutls_openpgp_privkey_import

685

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

686

if(ret != GNUTLS_E_SUCCESS){

687

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

688

safer_gnutls_strerror(ret));

689

privkey = NULL;

690

}

691

free(buffer.data);

692

buffer.data = NULL;

693

if(privkey != NULL){

694

/* Use private key to suggest an appropriate

695

sec_param */

696

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

697

gnutls_openpgp_privkey_deinit(privkey);

698

if(debug){

699

fprintf_plus(stderr, "This OpenPGP key implies using"

700

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

701

safe_string(gnutls_sec_param_get_name

702

(sec_param)));

703

}

704

}

705

}

706

}

707

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

708

/* Err on the side of caution */

709

sec_param = GNUTLS_SEC_PARAM_ULTRA;

710

if(debug){

711

fprintf_plus(stderr, "Falling back to security parameter"

712

" \"%s\"\n",

713

safe_string(gnutls_sec_param_get_name

714

(sec_param)));

715

}

716

}

717

}

718

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

719

if(uret != 0){

720

mc->dh_bits = uret;

721

if(debug){

722

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

723

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

724

safe_string(gnutls_sec_param_get_name

725

(sec_param)),

726

mc->dh_bits);

727

}

728

} else {

729

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

730

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

731

safe_string(gnutls_sec_param_get_name

732

(sec_param)),

733

safer_gnutls_strerror(ret));

734

goto globalfail;

735

}

736

} else if(debug){

737

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

738

mc->dh_bits);

739

}

740

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

741

if(ret != GNUTLS_E_SUCCESS){

742

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

743

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

744

safer_gnutls_strerror(ret));

745

goto globalfail;

746

}

747

}

748

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);

749

548

750

549

return 0;

751

550

752

551

globalfail:

753

552

754

gnutls_certificate_free_credentials(mc->cred);

755

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);

756

556

return -1;

757

557

}

758

558

759

__attribute__((nonnull, warn_unused_result))

760

static int init_gnutls_session(gnutls_session_t *session,

761

mandos_context *mc){

559

static int init_gnutls_session(gnutls_session_t *session){

762

560

int ret;

763

561

/* GnuTLS session creation */

764

562

do {

776

574

{

777

575

const char *err;

778

576

do {

779

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

577

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

780

578

if(quit_now){

781

579

gnutls_deinit(*session);

782

580

return -1;

793

591

794

592

do {

795

593

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

796

mc->cred);

594

mc.cred);

797

595

if(quit_now){

798

596

gnutls_deinit(*session);

799

597

return -1;

809

607

/* ignore client certificate if any. */

810

608

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

811

609

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

611

812

612

return 0;

813

613

}

814

614

816

616

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

817

617

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

818

618

819

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

820

__attribute__((warn_unused_result))

821

int raise_privileges(void){

822

int old_errno = errno;

823

int ret = 0;

824

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

825

ret = errno;

826

}

827

errno = old_errno;

828

return ret;

829

}

830

831

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

832

__attribute__((warn_unused_result))

833

int raise_privileges_permanently(void){

834

int old_errno = errno;

835

int ret = raise_privileges();

836

if(ret != 0){

837

errno = old_errno;

838

return ret;

839

}

840

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

841

ret = errno;

842

}

843

errno = old_errno;

844

return ret;

845

}

846

847

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

848

__attribute__((warn_unused_result))

849

int lower_privileges(void){

850

int old_errno = errno;

851

int ret = 0;

852

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

853

ret = errno;

854

}

855

errno = old_errno;

856

return ret;

857

}

858

859

/* Lower privileges permanently */

860

__attribute__((warn_unused_result))

861

int lower_privileges_permanently(void){

862

int old_errno = errno;

863

int ret = 0;

864

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

865

ret = errno;

866

}

867

errno = old_errno;

868

return ret;

869

}

870

871

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

872

__attribute__((nonnull, warn_unused_result))

873

static bool add_delete_local_route(const bool add,

874

const char *address,

875

AvahiIfIndex if_index){

876

int ret;

877

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

878

char add_arg[] = "add";

879

char delete_arg[] = "delete";

880

char debug_flag[] = "--debug";

881

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

882

if(pluginhelperdir == NULL){

883

if(debug){

884

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

885

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

886

}

887

return false;

888

}

889

890

char interface[IF_NAMESIZE];

891

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

892

perror_plus("if_indextoname");

893

return false;

894

}

895

896

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

897

if(devnull == -1){

898

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

899

return false;

900

}

901

pid_t pid = fork();

902

if(pid == 0){

903

/* Child */

904

/* Raise privileges */

905

errno = raise_privileges_permanently();

906

if(errno != 0){

907

perror_plus("Failed to raise privileges");

908

/* _exit(EX_NOPERM); */

909

} else {

910

/* Set group */

911

errno = 0;

912

ret = setgid(0);

913

if(ret == -1){

914

perror_plus("setgid");

915

_exit(EX_NOPERM);

916

}

917

/* Reset supplementary groups */

918

errno = 0;

919

ret = setgroups(0, NULL);

920

if(ret == -1){

921

perror_plus("setgroups");

922

_exit(EX_NOPERM);

923

}

924

}

925

ret = dup2(devnull, STDIN_FILENO);

926

if(ret == -1){

927

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

928

_exit(EX_OSERR);

929

}

930

ret = close(devnull);

931

if(ret == -1){

932

perror_plus("close");

933

_exit(EX_OSERR);

934

}

935

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

936

if(ret == -1){

937

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

938

_exit(EX_OSERR);

939

}

940

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

941

O_RDONLY

942

| O_DIRECTORY

943

| O_PATH

944

| O_CLOEXEC));

945

if(helperdir_fd == -1){

946

perror_plus("open");

947

_exit(EX_UNAVAILABLE);

948

}

949

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

950

helper, O_RDONLY));

951

if(helper_fd == -1){

952

perror_plus("openat");

953

close(helperdir_fd);

954

_exit(EX_UNAVAILABLE);

955

}

956

close(helperdir_fd);

957

#ifdef __GNUC__

958

#pragma GCC diagnostic push

959

#pragma GCC diagnostic ignored "-Wcast-qual"

960

#endif

961

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

962

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

963

interface, debug ? debug_flag : NULL, NULL },

964

environ) == -1){

965

#ifdef __GNUC__

966

#pragma GCC diagnostic pop

967

#endif

968

perror_plus("fexecve");

969

_exit(EXIT_FAILURE);

970

}

971

}

972

if(pid == -1){

973

perror_plus("fork");

974

return false;

975

}

976

int status;

977

pid_t pret = -1;

978

errno = 0;

979

do {

980

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

981

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

982

int errno_raising = 0;

983

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

984

errno_raising = errno;

985

perror_plus("Failed to raise privileges in order to"

986

" kill helper program");

987

}

988

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

989

perror_plus("kill");

990

}

991

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

992

perror_plus("Failed to lower privileges after killing"

993

" helper program");

994

}

995

return false;

996

}

997

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

998

if(pret == -1){

999

perror_plus("waitpid");

1000

return false;

1001

}

1002

if(WIFEXITED(status)){

1003

if(WEXITSTATUS(status) != 0){

1004

fprintf_plus(stderr, "Error: iprouteadddel exited"

1005

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

1006

return false;

1007

}

1008

return true;

1009

}

1010

if(WIFSIGNALED(status)){

1011

fprintf_plus(stderr, "Error: iprouteadddel died by"

1012

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

1013

return false;

1014

}

1015

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

1016

return false;

1017

}

1018

1019

__attribute__((nonnull, warn_unused_result))

1020

static bool add_local_route(const char *address,

1021

AvahiIfIndex if_index){

1022

if(debug){

1023

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

1024

}

1025

return add_delete_local_route(true, address, if_index);

1026

}

1027

1028

__attribute__((nonnull, warn_unused_result))

1029

static bool delete_local_route(const char *address,

1030

AvahiIfIndex if_index){

1031

if(debug){

1032

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

1033

}

1034

return add_delete_local_route(false, address, if_index);

1035

}

1036

1037

619

/* Called when a Mandos server is found */

1038

__attribute__((nonnull, warn_unused_result))

1039

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

620

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

1040

621

AvahiIfIndex if_index,

1041

int af, mandos_context *mc){

622

int af){

1042

623

int ret, tcp_sd = -1;

1043

624

ssize_t sret;

1044

struct sockaddr_storage to;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

1045

629

char *buffer = NULL;

1046

630

char *decrypted_buffer = NULL;

1047

631

size_t buffer_length = 0;

1050

634

int retval = -1;

1051

635

gnutls_session_t session;

1052

636

int pf; /* Protocol family */

1053

bool route_added = false;

1054

637

1055

638

errno = 0;

1056

639

1072

655

return -1;

1073

656

}

1074

657

1075

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

1076

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

1077

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

1078

bool match = false;

1079

{

1080

char *interface = NULL;

1081

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

1082

interface))){

1083

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

1084

match = true;

1085

break;

1086

}

1087

}

1088

}

1089

if(not match){

1090

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

1091

connect to the server */

1092

if(debug){

1093

char interface[IF_NAMESIZE];

1094

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

1095

perror_plus("if_indextoname");

1096

} else {

1097

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

1098

" \"%s\"\n",

1099

if_indextoname((unsigned int)if_index,

1100

interface));

1101

}

1102

}

1103

return -1;

1104

}

1105

}

1106

1107

ret = init_gnutls_session(&session, mc);

658

ret = init_gnutls_session(&session);

1108

659

if(ret != 0){

1109

660

return -1;

1110

661

}

1111

662

1112

663

if(debug){

1113

664

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

1114

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

665

PRIu16 "\n", ip, port);

1115

666

}

1116

667

1117

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

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1118

669

if(tcp_sd < 0){

1119

670

int e = errno;

1120

671

perror_plus("socket");

1127

678

goto mandos_end;

1128

679

}

1129

680

681

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

1130

682

if(af == AF_INET6){

1131

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

1132

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

1133

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);

1134

685

} else { /* IPv4 */

1135

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

1136

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

1137

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);

1138

688

}

1139

689

if(ret < 0 ){

1140

690

int e = errno;

1149

699

goto mandos_end;

1150

700

}

1151

701

if(af == AF_INET6){

1152

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

1153

if(IN6_IS_ADDR_LINKLOCAL

1154

(&((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*/

1155

709

if(if_index == AVAHI_IF_UNSPEC){

1156

710

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

1157

711

" incomplete without a network interface\n");

1159

713

goto mandos_end;

1160

714

}

1161

715

/* Set the network interface number as scope */

1162

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

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1163

717

}

1164

718

} else {

1165

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

719

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

720

-Wconversion and

721

-Wunreachable-code */

1166

722

}

1167

723

1168

724

if(quit_now){

1176

732

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

1177

733

perror_plus("if_indextoname");

1178

734

} else {

1179

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

1180

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

735

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

736

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

1181

737

}

1182

738

} else {

1183

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

1184

ip, (uintmax_t)port);

739

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

740

ip, port);

1185

741

}

1186

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1187

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1188

if(af == AF_INET6){

1189

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

1190

sizeof(struct sockaddr_in6),

1191

addrstr, sizeof(addrstr), NULL, 0,

1192

NI_NUMERICHOST);

1193

} else {

1194

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

1195

sizeof(struct sockaddr_in),

1196

addrstr, sizeof(addrstr), NULL, 0,

1197

NI_NUMERICHOST);

1198

}

1199

if(ret == EAI_SYSTEM){

1200

perror_plus("getnameinfo");

1201

} else if(ret != 0) {

1202

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

1203

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

1204

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

1205

}

1206

}

1207

1208

if(quit_now){

1209

errno = EINTR;

1210

goto mandos_end;

1211

}

1212

1213

while(true){

1214

if(af == AF_INET6){

1215

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

1216

sizeof(struct sockaddr_in6));

1217

} else {

1218

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

1219

sizeof(struct sockaddr_in));

1220

}

1221

if(ret < 0){

1222

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

1223

and if_index != AVAHI_IF_UNSPEC

1224

and connect_to == NULL

1225

and not route_added and

1226

((af == AF_INET6 and not

1227

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1228

&to)->sin6_addr)))

1229

or (af == AF_INET and

1230

/* Not a a IPv4LL address */

1231

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

1232

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

1233

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

1234

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

1235

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

1236

connect to a Mandos server announced by Avahi on a server

1237

host with a global address. Work around this by retrying

1238

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

1239

1240

Avahi bug reference:

1241

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

1242

https://bugs.debian.org/587961

1243

*/

1244

if(debug){

1245

fprintf_plus(stderr, "Mandos server unreachable, trying"

1246

" direct route\n");

1247

}

1248

int e = errno;

1249

route_added = add_local_route(ip, if_index);

1250

if(route_added){

1251

continue;

1252

}

1253

errno = e;

1254

}

1255

if(errno != ECONNREFUSED or debug){

1256

int e = errno;

1257

perror_plus("connect");

1258

errno = e;

1259

}

1260

goto mandos_end;

1261

}

1262

1263

if(quit_now){

1264

errno = EINTR;

1265

goto mandos_end;

1266

}

1267

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;

1268

783

}

1269

784

1270

785

const char *out = mandos_protocol_version;

1306

821

goto mandos_end;

1307

822

}

1308

823

1309

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

1310

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

1311

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

1312

gnutls_transport_set_ptr(session,

1313

(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);

1314

826

1315

827

if(quit_now){

1316

828

errno = EINTR;

1421

933

if(buffer_length > 0){

1422

934

ssize_t decrypted_buffer_size;

1423

935

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1424

&decrypted_buffer, mc);

936

&decrypted_buffer);

1425

937

if(decrypted_buffer_size >= 0){

1426

938

1427

clearerr(stdout);

1428

939

written = 0;

1429

940

while(written < (size_t) decrypted_buffer_size){

1430

941

if(quit_now){

1446

957

}

1447

958

written += (size_t)ret;

1448

959

}

1449

ret = fflush(stdout);

1450

if(ret != 0){

1451

int e = errno;

1452

if(debug){

1453

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

1454

strerror(errno));

1455

}

1456

errno = e;

1457

goto mandos_end;

1458

}

1459

960

retval = 0;

1460

961

}

1461

962

}

1464

965

1465

966

mandos_end:

1466

967

{

1467

if(route_added){

1468

if(not delete_local_route(ip, if_index)){

1469

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

1470

" interface %d", ip, if_index);

1471

}

1472

}

1473

968

int e = errno;

1474

969

free(decrypted_buffer);

1475

970

free(buffer);

1476

971

if(tcp_sd >= 0){

1477

ret = close(tcp_sd);

972

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

1478

973

}

1479

974

if(ret == -1){

1480

975

if(e == 0){

1492

987

return retval;

1493

988

}

1494

989

1495

__attribute__((nonnull))

1496

990

static void resolve_callback(AvahiSServiceResolver *r,

1497

991

AvahiIfIndex interface,

1498

992

AvahiProtocol proto,

1506

1000

AVAHI_GCC_UNUSED AvahiStringList *txt,

1507

1001

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1508

1002

flags,

1509

void *mc){

1510

if(r == NULL){

1511

return;

1512

}

1003

AVAHI_GCC_UNUSED void* userdata){

1004

assert(r);

1513

1005

1514

1006

/* Called whenever a service has been resolved successfully or

1515

1007

timed out */

1516

1008

1517

1009

if(quit_now){

1518

avahi_s_service_resolver_free(r);

1519

1010

return;

1520

1011

}

1521

1012

1525

1016

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

1526

1017

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

1527

1018

domain,

1528

avahi_strerror(avahi_server_errno

1529

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

1019

avahi_strerror(avahi_server_errno(mc.server)));

1530

1020

break;

1531

1021

1532

1022

case AVAHI_RESOLVER_FOUND:

1538

1028

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

1539

1029

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

1540

1030

}

1541

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

1542

interface,

1543

avahi_proto_to_af(proto),

1544

mc);

1031

int ret = start_mandos_communication(ip, port, interface,

1032

avahi_proto_to_af(proto));

1545

1033

if(ret == 0){

1546

avahi_simple_poll_quit(simple_poll);

1034

avahi_simple_poll_quit(mc.simple_poll);

1547

1035

} else {

1548

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

1549

avahi_proto_to_af(proto),

1550

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

1036

if(not add_server(ip, port, interface,

1037

avahi_proto_to_af(proto))){

1551

1038

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

1552

1039

" list\n", name);

1553

1040

}

1566

1053

const char *domain,

1567

1054

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1568

1055

flags,

1569

void *mc){

1570

if(b == NULL){

1571

return;

1572

}

1056

AVAHI_GCC_UNUSED void* userdata){

1057

assert(b);

1573

1058

1574

1059

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

1575

1060

is removed from the LAN */

1583

1068

case AVAHI_BROWSER_FAILURE:

1584

1069

1585

1070

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

1586

avahi_strerror(avahi_server_errno

1587

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

1588

avahi_simple_poll_quit(simple_poll);

1071

avahi_strerror(avahi_server_errno(mc.server)));

1072

avahi_simple_poll_quit(mc.simple_poll);

1589

1073

return;

1590

1074

1591

1075

case AVAHI_BROWSER_NEW:

1594

1078

the callback function is called the Avahi server will free the

1595

1079

resolver for us. */

1596

1080

1597

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

1598

interface, protocol, name, type,

1599

domain, protocol, 0,

1600

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)

1601

1084

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

1602

1085

" %s\n", name,

1603

avahi_strerror(avahi_server_errno

1604

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

1086

avahi_strerror(avahi_server_errno(mc.server)));

1605

1087

break;

1606

1088

1607

1089

case AVAHI_BROWSER_REMOVE:

1626

1108

signal_received = sig;

1627

1109

int old_errno = errno;

1628

1110

/* set main loop to exit */

1629

if(simple_poll != NULL){

1630

avahi_simple_poll_quit(simple_poll);

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1631

1113

}

1632

1114

errno = old_errno;

1633

1115

}

1634

1116

1635

__attribute__((nonnull, warn_unused_result))

1636

1117

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

1637

1118

int ret;

1638

int old_errno;

1639

1119

1640

1120

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

1641

1121

if(s < 0){

1642

old_errno = errno;

1643

1122

perror_plus("socket");

1644

errno = old_errno;

1645

1123

return false;

1646

1124

}

1647

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

1648

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

1125

strcpy(ifr->ifr_name, ifname);

1649

1126

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1650

1127

if(ret == -1){

1651

1128

if(debug){

1652

old_errno = errno;

1653

1129

perror_plus("ioctl SIOCGIFFLAGS");

1654

errno = old_errno;

1655

1130

}

1656

1131

return false;

1657

1132

}

1658

1133

return true;

1659

1134

}

1660

1135

1661

__attribute__((nonnull, warn_unused_result))

1662

1136

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

1663

1137

1664

1138

/* Reject the loopback device */

1706

1180

* corresponds to an acceptable network device.

1707

1181

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

1708

1182

*/

1709

__attribute__((nonnull, warn_unused_result))

1710

1183

int good_interface(const struct dirent *if_entry){

1711

1184

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

1712

1185

return 0;

1728

1201

}

1729

1202

1730

1203

/*

1731

* This function determines if a network interface is up.

1732

*/

1733

__attribute__((nonnull, warn_unused_result))

1734

bool interface_is_up(const char *interface){

1735

struct ifreq ifr;

1736

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

1737

if(debug){

1738

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

1739

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

1740

}

1741

return false;

1742

}

1743

1744

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

1745

}

1746

1747

/*

1748

* This function determines if a network interface is running

1749

*/

1750

__attribute__((nonnull, warn_unused_result))

1751

bool interface_is_running(const char *interface){

1752

struct ifreq ifr;

1753

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

1754

if(debug){

1755

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

1756

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

1757

}

1758

return false;

1759

}

1760

1761

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

1762

}

1763

1764

__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

1765

1246

int notdotentries(const struct dirent *direntry){

1766

1247

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

1767

1248

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

1774

1255

}

1775

1256

1776

1257

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

1777

__attribute__((nonnull, warn_unused_result))

1778

1258

int runnable_hook(const struct dirent *direntry){

1779

1259

int ret;

1780

1260

size_t sret;

1788

1268

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

1789

1269

"abcdefghijklmnopqrstuvwxyz"

1790

1270

"0123456789"

1791

"_.-");

1271

"_-");

1792

1272

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

1793

1273

/* Contains non-allowed characters */

1794

1274

if(debug){

1798

1278

return 0;

1799

1279

}

1800

1280

1801

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);

1802

1289

if(ret == -1){

1803

1290

if(debug){

1804

1291

perror_plus("Could not stat hook");

1828

1315

return 1;

1829

1316

}

1830

1317

1831

__attribute__((nonnull, warn_unused_result))

1832

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1833

mandos_context *mc){

1318

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1834

1319

int ret;

1835

1320

struct timespec now;

1836

1321

struct timespec waited_time;

1837

1322

intmax_t block_time;

1838

1323

1839

1324

while(true){

1840

if(mc->current_server == NULL){

1841

if(debug){

1325

if(mc.current_server == NULL){

1326

if (debug){

1842

1327

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

1843

1328

" No timeout!\n");

1844

1329

}

1845

1330

ret = avahi_simple_poll_iterate(s, -1);

1846

1331

} else {

1847

if(debug){

1332

if (debug){

1848

1333

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

1849

1334

" it, or wait\n");

1850

1335

}

1857

1342

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

1858

1343

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

1859

1344

waited_time.tv_sec = (now.tv_sec

1860

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

1345

- mc.current_server->last_seen.tv_sec);

1861

1346

waited_time.tv_nsec = (now.tv_nsec

1862

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

1347

- mc.current_server->last_seen.tv_nsec);

1863

1348

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

1864

1349

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

1865

1350

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

1867

1352

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

1868

1353

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

1869

1354

1870

if(debug){

1355

if (debug){

1871

1356

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

1872

1357

block_time);

1873

1358

}

1874

1359

1875

1360

if(block_time <= 0){

1876

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

1877

mc->current_server->port,

1878

mc->current_server->if_index,

1879

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);

1880

1365

if(ret == 0){

1881

avahi_simple_poll_quit(s);

1366

avahi_simple_poll_quit(mc.simple_poll);

1882

1367

return 0;

1883

1368

}

1884

1369

ret = clock_gettime(CLOCK_MONOTONIC,

1885

&mc->current_server->last_seen);

1370

&mc.current_server->last_seen);

1886

1371

if(ret == -1){

1887

1372

perror_plus("clock_gettime");

1888

1373

return -1;

1889

1374

}

1890

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

1375

mc.current_server = mc.current_server->next;

1891

1376

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

1892

1377

servers, but don't block */

1893

1378

}

1895

1380

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

1896

1381

}

1897

1382

if(ret != 0){

1898

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

1383

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

1899

1384

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

1900

1385

}

1901

1386

}

1902

1387

}

1903

1388

}

1904

1389

1905

__attribute__((nonnull))

1906

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

1390

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

1907

1391

const float delay){

1908

struct dirent **direntries = NULL;

1909

if(hookdir_fd == -1){

1910

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1911

| O_CLOEXEC);

1912

if(hookdir_fd == -1){

1913

if(errno == ENOENT){

1914

if(debug){

1915

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

1916

" found\n", hookdir);

1917

}

1918

} else {

1919

perror_plus("open");

1920

}

1921

return;

1922

}

1923

}

1924

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

1925

runnable_hook, alphasort);

1392

struct dirent **direntries;

1393

struct dirent *direntry;

1394

int ret;

1395

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

1396

alphasort);

1926

1397

if(numhooks == -1){

1927

1398

perror_plus("scandir");

1928

return;

1929

}

1930

struct dirent *direntry;

1931

int ret;

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1937

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

1938

direntry = direntries[i];

1939

if(debug){

1940

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

1941

direntry->d_name);

1942

}

1943

pid_t hook_pid = fork();

1944

if(hook_pid == 0){

1945

/* Child */

1946

/* Raise privileges */

1947

errno = raise_privileges_permanently();

1948

if(errno != 0){

1949

perror_plus("Failed to raise privileges");

1950

_exit(EX_NOPERM);

1951

}

1952

/* Set group */

1953

errno = 0;

1954

ret = setgid(0);

1955

if(ret == -1){

1956

perror_plus("setgid");

1957

_exit(EX_NOPERM);

1958

}

1959

/* Reset supplementary groups */

1960

errno = 0;

1961

ret = setgroups(0, NULL);

1962

if(ret == -1){

1963

perror_plus("setgroups");

1964

_exit(EX_NOPERM);

1965

}

1966

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

1967

if(ret == -1){

1968

perror_plus("setenv");

1969

_exit(EX_OSERR);

1970

}

1971

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

1972

if(ret == -1){

1973

perror_plus("setenv");

1974

_exit(EX_OSERR);

1975

}

1976

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

1977

if(ret == -1){

1978

perror_plus("setenv");

1979

_exit(EX_OSERR);

1980

}

1981

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

1982

if(ret == -1){

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

char *delaystring;

1987

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

1988

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){

1989

1406

perror_plus("asprintf");

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

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

}

1994

1475

free(delaystring);

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

free(delaystring);

1999

if(connect_to != NULL){

2000

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

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

}

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

2009

if(hook_fd == -1){

2010

perror_plus("openat");

2011

_exit(EXIT_FAILURE);

2012

}

2013

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

2014

perror_plus("close");

2015

_exit(EXIT_FAILURE);

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

ret = close(devnull);

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

2032

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

2033

environ) == -1){

2034

perror_plus("fexecve");

2035

_exit(EXIT_FAILURE);

2036

}

2037

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

int status;

2044

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

2045

perror_plus("waitpid");

2046

free(direntry);

2047

continue;

2048

}

2049

if(WIFEXITED(status)){

2050

if(WEXITSTATUS(status) != 0){

2051

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

2052

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

2053

WEXITSTATUS(status));

2054

free(direntry);

2055

continue;

2056

}

2057

} else if(WIFSIGNALED(status)){

2058

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

2059

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

2060

WTERMSIG(status));

2061

free(direntry);

2062

continue;

2063

} else {

2064

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

2065

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

2066

free(direntry);

2067

continue;

2068

}

2069

}

2070

if(debug){

2071

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

2072

direntry->d_name);

2073

}

2074

free(direntry);

2075

}

2076

free(direntries);

2077

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

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

2083

}

2084

2085

__attribute__((nonnull, warn_unused_result))

2086

int bring_up_interface(const char *const interface,

2087

const float delay){

2088

int old_errno = errno;

2089

int ret;

2090

struct ifreq network;

2091

unsigned int if_index = if_nametoindex(interface);

2092

if(if_index == 0){

2093

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

2094

errno = old_errno;

2095

return ENXIO;

2096

}

2097

2098

if(quit_now){

2099

errno = old_errno;

2100

return EINTR;

2101

}

2102

2103

if(not interface_is_up(interface)){

2104

int ret_errno = 0;

2105

int ioctl_errno = 0;

2106

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

2107

ret_errno = errno;

2108

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

2109

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

2110

errno = old_errno;

2111

return ret_errno;

2112

}

2113

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

2114

2115

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

2116

if(sd == -1){

2117

ret_errno = errno;

2118

perror_plus("socket");

2119

errno = old_errno;

2120

return ret_errno;

2121

}

2122

2123

if(quit_now){

2124

ret = close(sd);

2125

if(ret == -1){

2126

perror_plus("close");

2127

}

2128

errno = old_errno;

2129

return EINTR;

2130

}

2131

2132

if(debug){

2133

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

2134

interface);

2135

}

2136

2137

/* Raise privileges */

2138

ret_errno = raise_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to raise privileges");

2142

}

2143

2144

#ifdef __linux__

2145

int ret_linux;

2146

bool restore_loglevel = false;

2147

if(ret_errno == 0){

2148

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2149

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

2150

ret_linux = klogctl(8, NULL, 5);

2151

if(ret_linux == -1){

2152

perror_plus("klogctl");

2153

} else {

2154

restore_loglevel = true;

2155

}

2156

}

2157

#endif /* __linux__ */

2158

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

2159

ioctl_errno = errno;

2160

#ifdef __linux__

2161

if(restore_loglevel){

2162

ret_linux = klogctl(7, NULL, 0);

2163

if(ret_linux == -1){

2164

perror_plus("klogctl");

2165

}

2166

}

2167

#endif /* __linux__ */

2168

2169

/* If raise_privileges() succeeded above */

2170

if(ret_errno == 0){

2171

/* Lower privileges */

2172

ret_errno = lower_privileges();

2173

if(ret_errno != 0){

2174

errno = ret_errno;

2175

perror_plus("Failed to lower privileges");

2176

}

2177

}

2178

2179

/* Close the socket */

2180

ret = close(sd);

2181

if(ret == -1){

2182

perror_plus("close");

2183

}

2184

2185

if(ret_setflags == -1){

2186

errno = ioctl_errno;

2187

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2188

errno = old_errno;

2189

return ioctl_errno;

2190

}

2191

} else if(debug){

2192

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

2193

interface);

2194

}

2195

2196

/* Sleep checking until interface is running.

2197

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

2198

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

2199

if(interface_is_running(interface)){

2200

break;

2201

}

2202

struct timespec sleeptime = { .tv_nsec = 250000000 };

2203

ret = nanosleep(&sleeptime, NULL);

2204

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

2205

perror_plus("nanosleep");

2206

}

2207

}

2208

2209

errno = old_errno;

2210

return 0;

2211

}

2212

2213

__attribute__((nonnull, warn_unused_result))

2214

int take_down_interface(const char *const interface){

2215

int old_errno = errno;

2216

struct ifreq network;

2217

unsigned int if_index = if_nametoindex(interface);

2218

if(if_index == 0){

2219

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

2220

errno = old_errno;

2221

return ENXIO;

2222

}

2223

if(interface_is_up(interface)){

2224

int ret_errno = 0;

2225

int ioctl_errno = 0;

2226

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

2227

ret_errno = errno;

2228

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

2229

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

2230

errno = old_errno;

2231

return ret_errno;

2232

}

2233

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

2234

2235

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

2236

if(sd == -1){

2237

ret_errno = errno;

2238

perror_plus("socket");

2239

errno = old_errno;

2240

return ret_errno;

2241

}

2242

2243

if(debug){

2244

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

2245

interface);

2246

}

2247

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

2254

2255

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

2256

ioctl_errno = errno;

2257

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

2267

2268

/* Close the socket */

2269

int ret = close(sd);

2270

if(ret == -1){

2271

perror_plus("close");

2272

}

2273

2274

if(ret_setflags == -1){

2275

errno = ioctl_errno;

2276

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2277

errno = old_errno;

2278

return ioctl_errno;

2279

}

2280

} else if(debug){

2281

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

2282

interface);

2283

}

2284

2285

errno = old_errno;

2286

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;

2287

1524

}

2288

1525

2289

1526

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

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

2295

1527

AvahiSServiceBrowser *sb = NULL;

2296

error_t ret_errno;

1528

int error;

2297

1529

int ret;

2298

1530

intmax_t tmpmax;

2299

1531

char *tmp;

2300

1532

int exitcode = EXIT_SUCCESS;

2301

char *interfaces_to_take_down = NULL;

2302

size_t interfaces_to_take_down_size = 0;

2303

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

2304

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

2305

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;

2306

1541

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2307

1542

const char *seckey = PATHDIR "/" SECKEY;

2308

1543

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

2310

char *interfaces_hooks = NULL;

2311

1544

2312

1545

bool gnutls_initialized = false;

2313

1546

bool gpgme_initialized = false;

2365

1598

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

2366

1599

" Diffie-Hellman key exchange",

2367

1600

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

2373

1601

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

2374

1602

.arg = "STRING",

2375

1603

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

2409

1637

connect_to = arg;

2410

1638

break;

2411

1639

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

2412

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

2413

arg, (int)',');

2414

if(ret_errno != 0){

2415

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

2416

}

1640

interface = arg;

2417

1641

break;

2418

1642

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

2419

1643

seckey = arg;

2430

1654

}

2431

1655

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

2432

1656

break;

2433

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

2434

dh_params_file = arg;

2435

break;

2436

1657

case 130: /* --priority */

2437

1658

mc.priority = arg;

2438

1659

break;

2478

1699

.args_doc = "",

2479

1700

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

2480

1701

" passwords from a Mandos server" };

2481

ret_errno = argp_parse(&argp, argc, argv,

2482

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2483

switch(ret_errno){

1702

ret = argp_parse(&argp, argc, argv,

1703

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1704

switch(ret){

2484

1705

case 0:

2485

1706

break;

2486

1707

case ENOMEM:

2487

1708

default:

2488

errno = ret_errno;

1709

errno = ret;

2489

1710

perror_plus("argp_parse");

2490

1711

exitcode = EX_OSERR;

2491

1712

goto end;

2494

1715

goto end;

2495

1716

}

2496

1717

}

2497

1718

2498

1719

{

2499

1720

/* Work around Debian bug #633582:

2500

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

1721

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

2501

1722

2502

/* Re-raise privileges */

2503

ret = raise_privileges();

2504

if(ret != 0){

2505

errno = ret;

2506

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");

2507

1728

} else {

2508

1729

struct stat st;

2509

1730

2524

1745

}

2525

1746

}

2526

1747

}

2527

close(seckey_fd);

1748

TEMP_FAILURE_RETRY(close(seckey_fd));

2528

1749

}

2529

1750

}

2530

1751

2531

1752

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

2532

1753

int pubkey_fd = open(pubkey, O_RDONLY);

2533

1754

if(pubkey_fd == -1){

2545

1766

}

2546

1767

}

2547

1768

}

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

1769

TEMP_FAILURE_RETRY(close(pubkey_fd));

1770

}

1771

}

1772

2574

1773

/* Lower privileges */

2575

ret = lower_privileges();

2576

if(ret != 0){

2577

errno = ret;

2578

perror_plus("Failed to lower privileges");

2579

}

2580

}

2581

}

2582

2583

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

2584

{

2585

char *interface = NULL;

2586

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

2587

interface))){

2588

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

2589

and if_nametoindex(interface) == 0){

2590

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

2591

fprintf_plus(stderr, "Not using nonexisting interface"

2592

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

2593

}

2594

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

2595

interface = NULL;

1774

errno = 0;

1775

ret = seteuid(uid);

1776

if(ret == -1){

1777

perror_plus("seteuid");

2596

1778

}

2597

1779

}

2598

1780

}

2599

1781

2600

1782

/* Run network hooks */

2601

{

2602

if(mc.interfaces != NULL){

2603

interfaces_hooks = malloc(mc.interfaces_size);

2604

if(interfaces_hooks == NULL){

2605

perror_plus("malloc");

2606

goto end;

2607

}

2608

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

2609

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

2610

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

1783

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

1784

goto end;

2613

1785

}

2614

1786

2615

1787

if(not debug){

2616

1788

avahi_set_log_function(empty_log);

2617

1789

}

2618

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

2619

1823

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

2620

1824

from the signal handler */

2621

1825

/* Initialize the pseudo-RNG for Avahi */

2622

1826

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

2623

simple_poll = avahi_simple_poll_new();

2624

if(simple_poll == NULL){

1827

mc.simple_poll = avahi_simple_poll_new();

1828

if(mc.simple_poll == NULL){

2625

1829

fprintf_plus(stderr,

2626

1830

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

2627

1831

exitcode = EX_UNAVAILABLE;

2691

1895

}

2692

1896

}

2693

1897

2694

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

2695

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2697

/* Look for any good interfaces */

2698

ret = scandir(sys_class_net, &direntries, good_interface,

2699

alphasort);

2700

if(ret >= 1){

2701

/* Add all found interfaces to interfaces list */

2702

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

2703

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

2704

direntries[i]->d_name);

2705

if(ret_errno != 0){

2706

errno = ret_errno;

2707

perror_plus("argz_add");

2708

free(direntries[i]);

2709

continue;

2710

}

2711

if(debug){

2712

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

2713

direntries[i]->d_name);

2714

}

2715

free(direntries[i]);

2716

}

2717

free(direntries);

2718

} else {

2719

if(ret == 0){

2720

free(direntries);

2721

}

2722

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

2723

exitcode = EXIT_FAILURE;

2724

goto end;

2725

}

2726

}

2727

2728

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

2729

{

2730

char *interface = NULL;

2731

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

2732

interface))){

2733

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

2734

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

2735

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

2736

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

2737

interface);

2738

interface = NULL;

2739

while((interface = argz_next(mc.interfaces,

2740

mc.interfaces_size, interface))){

2741

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

2742

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

2743

interface);

2744

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");

2745

1983

}

2746

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){

2747

2002

break;

2748

2003

}

2749

bool interface_was_up = interface_is_up(interface);

2750

errno = bring_up_interface(interface, delay);

2751

if(not interface_was_up){

2752

if(errno != 0){

2753

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

2754

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

2755

} else {

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

2760

perror_plus("argz_add");

2761

}

2762

}

2763

}

2764

}

2765

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

2766

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

2767

}

2768

}

2769

2770

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

2771

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

2772

if(debug){

2773

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

2774

mc.interfaces);

2775

}

2776

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

}

2777

2033

}

2778

2034

2779

2035

if(quit_now){

2780

2036

goto end;

2781

2037

}

2782

2038

2783

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

2039

ret = init_gnutls_global(pubkey, seckey);

2784

2040

if(ret == -1){

2785

2041

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

2786

2042

exitcode = EX_UNAVAILABLE;

2793

2049

goto end;

2794

2050

}

2795

2051

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

2052

if(mkdtemp(tempdir) == NULL){

2806

2053

perror_plus("mkdtemp");

2807

2054

goto end;

2808

2055

}

2056

tempdir_created = true;

2809

2057

2810

2058

if(quit_now){

2811

2059

goto end;

2812

2060

}

2813

2061

2814

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

2062

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

2815

2063

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

2816

2064

exitcode = EX_UNAVAILABLE;

2817

2065

goto end;

2827

2075

/* Connect directly, do not use Zeroconf */

2828

2076

/* (Mainly meant for debugging) */

2829

2077

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

2830

2831

2078

if(address == NULL){

2832

2079

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

2833

2080

exitcode = EX_USAGE;

2838

2085

goto end;

2839

2086

}

2840

2087

2841

in_port_t port;

2088

uint16_t port;

2842

2089

errno = 0;

2843

2090

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

2844

2091

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

2845

or tmpmax != (in_port_t)tmpmax){

2092

or tmpmax != (uint16_t)tmpmax){

2846

2093

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

2847

2094

exitcode = EX_USAGE;

2848

2095

goto end;

2849

2096

}

2850

2097

2851

2098

if(quit_now){

2852

2099

goto end;

2853

2100

}

2854

2101

2855

port = (in_port_t)tmpmax;

2102

port = (uint16_t)tmpmax;

2856

2103

*address = '\0';

2857

2104

/* Colon in address indicates IPv6 */

2858

2105

int af;

2874

2121

}

2875

2122

2876

2123

while(not quit_now){

2877

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

2878

&mc);

2124

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

2879

2125

if(quit_now or ret == 0){

2880

2126

break;

2881

2127

}

2883

2129

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

2884

2130

(int)retry_interval);

2885

2131

}

2886

sleep((unsigned int)retry_interval);

2132

sleep((int)retry_interval);

2887

2133

}

2888

2134

2889

if(not quit_now){

2135

if (not quit_now){

2890

2136

exitcode = EXIT_SUCCESS;

2891

2137

}

2892

2138

2907

2153

config.publish_domain = 0;

2908

2154

2909

2155

/* Allocate a new server */

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2911

&config, NULL, NULL, &ret);

2156

mc.server = avahi_server_new(avahi_simple_poll_get

2157

(mc.simple_poll), &config, NULL,

2158

NULL, &error);

2912

2159

2913

2160

/* Free the Avahi configuration data */

2914

2161

avahi_server_config_free(&config);

2917

2164

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

2918

2165

if(mc.server == NULL){

2919

2166

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

2920

avahi_strerror(ret));

2167

avahi_strerror(error));

2921

2168

exitcode = EX_UNAVAILABLE;

2922

2169

goto end;

2923

2170

}

2929

2176

/* Create the Avahi service browser */

2930

2177

sb = avahi_s_service_browser_new(mc.server, if_index,

2931

2178

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2932

NULL, 0, browse_callback,

2933

(void *)&mc);

2179

NULL, 0, browse_callback, NULL);

2934

2180

if(sb == NULL){

2935

2181

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

2936

2182

avahi_strerror(avahi_server_errno(mc.server)));

2947

2193

if(debug){

2948

2194

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

2949

2195

}

2950

2951

ret = avahi_loop_with_timeout(simple_poll,

2952

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

2196

2197

ret = avahi_loop_with_timeout(mc.simple_poll,

2198

(int)(retry_interval * 1000));

2953

2199

if(debug){

2954

2200

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

2955

2201

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

2958

2204

end:

2959

2205

2960

2206

if(debug){

2961

if(signal_received){

2962

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

2963

argv[0], signal_received,

2964

strsignal(signal_received));

2965

} else {

2966

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

2967

}

2207

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

2968

2208

}

2969

2209

2970

2210

/* Cleanup things */

2971

free(mc.interfaces);

2972

2973

2211

if(sb != NULL)

2974

2212

avahi_s_service_browser_free(sb);

2975

2213

2976

2214

if(mc.server != NULL)

2977

2215

avahi_server_free(mc.server);

2978

2216

2979

if(simple_poll != NULL)

2980

avahi_simple_poll_free(simple_poll);

2217

if(mc.simple_poll != NULL)

2218

avahi_simple_poll_free(mc.simple_poll);

2981

2219

2982

2220

if(gnutls_initialized){

2983

2221

gnutls_certificate_free_credentials(mc.cred);

2222

gnutls_global_deinit();

2984

2223

gnutls_dh_params_deinit(mc.dh_params);

2985

2224

}

2986

2225

2994

2233

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

2995

2234

while(mc.current_server != NULL){

2996

2235

server *next = mc.current_server->next;

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic push

2999

#pragma GCC diagnostic ignored "-Wcast-qual"

3000

#endif

3001

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

3002

#ifdef __GNUC__

3003

#pragma GCC diagnostic pop

3004

#endif

3005

2236

free(mc.current_server);

3006

2237

mc.current_server = next;

3007

2238

}

3008

2239

}

3009

2240

3010

/* Re-raise privileges */

2241

/* Run network hooks */

2242

run_network_hooks("stop", interface, delay);

2243

2244

/* Re-raise priviliges */

3011

2245

{

3012

ret = raise_privileges();

3013

if(ret != 0){

3014

errno = ret;

3015

perror_plus("Failed to raise privileges");

3016

} else {

3017

3018

/* Run network hooks */

3019

run_network_hooks("stop", interfaces_hooks != NULL ?

3020

interfaces_hooks : "", delay);

3021

3022

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

3023

{

3024

char *interface = NULL;

3025

while((interface=argz_next(interfaces_to_take_down,

3026

interfaces_to_take_down_size,

3027

interface))){

3028

ret = take_down_interface(interface);

3029

if(ret != 0){

3030

errno = ret;

3031

perror_plus("Failed to take down interface");

3032

}

3033

}

3034

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

3035

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

3036

" down\n");

3037

}

3038

}

2246

errno = 0;

2247

ret = seteuid(0);

2248

if(ret == -1){

2249

perror_plus("seteuid");

3039

2250

}

3040

2251

3041

ret = lower_privileges_permanently();

3042

if(ret != 0){

3043

errno = ret;

3044

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

}

3045

2268

}

3046

2269

}

3047

3048

free(interfaces_to_take_down);

3049

free(interfaces_hooks);

3050

3051

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

3052

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){

3053

2279

struct dirent **direntries = NULL;

3054

int dret;

3055

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

3056

O_RDONLY

3057

| O_NOFOLLOW

3058

| O_DIRECTORY

3059

| O_PATH));

3060

if(dir_fd == -1){

3061

perror_plus("open");

3062

}

3063

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

3064

notdotentries, alphasort);

3065

if(numentries >= 0){

2280

struct dirent *direntry = NULL;

2281

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

2282

alphasort);

2283

if (numentries > 0){

3066

2284

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

3067

if(debug){

3068

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

3069

dirname, direntries[i]->d_name);

3070

}

3071

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

3072

if(dret == -1){

3073

if(errno == EISDIR){

3074

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

3075

AT_REMOVEDIR);

3076

}

3077

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

3078

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

3079

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

3080

/* Recurse only in this special case */

3081

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

3082

dret = 0;

3083

}

3084

if(dret == -1){

3085

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

3086

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

3087

}

3088

}

3089

free(direntries[i]);

3090

}

3091

3092

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

3093

free(direntries);

3094

if(numentries == -1){

3095

perror_plus("scandirat");

3096

}

3097

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3098

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

3099

perror_plus("rmdir");

3100

}

3101

} else {

3102

perror_plus("scandirat");

3103

}

3104

close(dir_fd);

3105

}

3106

3107

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

3108

if(tempdir != NULL){

3109

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

}

3110

2311

}

3111

2312

3112

2313

if(quit_now){