/mandos/release : revision 237.7.441

9

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

10

*

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* Everything else is

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13

12

13

14

*

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

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#endif

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#endif /* not _FILE_OFFSET_BITS */

39

40

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

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

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stdout, ferror(), remove() */

44

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

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stdout, ferror() */

44

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

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

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

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strtof(), abort() */

48

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

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

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

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

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asprintf(), strncpy(), strsignal()

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*/

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52

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

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53

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

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sockaddr_in6, PF_INET6,

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opendir(), DIR */

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

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

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inet_pton(), connect() */

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

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inet_pton(), connect(),

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getnameinfo() */

61

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

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62

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

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63

*/

62

64

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

63

65

strtoimax() */

64

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

65

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

66

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

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EAI_SYSTEM, ENETUNREACH,

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EHOSTUNREACH, ECONNREFUSED, EPROTO,

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EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

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ENOTEMPTY,

66

71

program_invocation_short_name */

67

72

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

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73

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

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78

*/

74

79

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

75

80

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

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

77

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

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

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unlinkat() */

83

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

78

84

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

79

85

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

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86

argp_state, struct argp,

88

94

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

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95

WEXITSTATUS(), WTERMSIG() */

90

96

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

97

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

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

100

argz_count() */

101

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

102

EAI_SYSTEM, gai_strerror() */

91

103

92

104

#ifdef __linux__

93

105

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

135

147

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

136

148

char *connect_to = NULL;

137

149

const char *hookdir = HOOKDIR;

150

int hookdir_fd = -1;

151

uid_t uid = 65534;

152

gid_t gid = 65534;

138

153

139

154

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

140

155

typedef struct server{

141

156

const char *ip;

142

uint16_t port;

157

in_port_t port;

143

158

AvahiIfIndex if_index;

144

159

int af;

145

160

struct timespec last_seen;

149

164

150

165

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

151

166

typedef struct {

152

AvahiSimplePoll *simple_poll;

153

167

AvahiServer *server;

154

168

gnutls_certificate_credentials_t cred;

155

169

unsigned int dh_bits;

157

171

const char *priority;

158

172

gpgme_ctx_t ctx;

159

173

server *current_server;

174

char *interfaces;

175

size_t interfaces_size;

160

176

} mandos_context;

161

177

162

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

163

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

164

.dh_bits = 1024, .priority = "SECURE256"

165

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

166

.current_server = NULL };

178

/* global so signal handler can reach it*/

179

AvahiSimplePoll *simple_poll;

167

180

168

181

sig_atomic_t quit_now = 0;

169

182

int signal_received = 0;

170

183

171

184

/* Function to use when printing errors */

172

185

void perror_plus(const char *print_text){

186

int e = errno;

173

187

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

174

188

program_invocation_short_name);

189

errno = e;

175

190

perror(print_text);

176

191

}

177

192

193

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

178

194

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

179

195

va_list ap;

180

196

va_start (ap, format);

181

197

182

198

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

183

199

program_invocation_short_name));

184

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

200

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

185

201

}

186

202

187

203

/*

189

205

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

190

206

* "buffer_length" is how much is already used.

191

207

*/

208

__attribute__((nonnull, warn_unused_result))

192

209

size_t incbuffer(char **buffer, size_t buffer_length,

193

210

size_t buffer_capacity){

194

211

if(buffer_length + BUFFER_SIZE > buffer_capacity){

195

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

196

if(buffer == NULL){

212

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

213

if(new_buf == NULL){

214

int old_errno = errno;

215

free(*buffer);

216

errno = old_errno;

217

*buffer = NULL;

197

218

return 0;

198

219

}

220

*buffer = new_buf;

199

221

buffer_capacity += BUFFER_SIZE;

200

222

}

201

223

return buffer_capacity;

202

224

}

203

225

204

226

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

205

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

206

int af){

227

__attribute__((nonnull, warn_unused_result))

228

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

229

int af, server **current_server){

207

230

int ret;

208

231

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

209

232

if(new_server == NULL){

210

233

perror_plus("malloc");

211

return -1;

234

return false;

212

235

}

213

236

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

214

237

.port = port,

216

239

.af = af };

217

240

if(new_server->ip == NULL){

218

241

perror_plus("strdup");

219

return -1;

242

free(new_server);

243

return false;

244

}

245

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

246

if(ret == -1){

247

perror_plus("clock_gettime");

248

#ifdef __GNUC__

249

#pragma GCC diagnostic push

250

#pragma GCC diagnostic ignored "-Wcast-qual"

251

#endif

252

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

253

#ifdef __GNUC__

254

#pragma GCC diagnostic pop

255

#endif

256

free(new_server);

257

return false;

220

258

}

221

259

/* Special case of first server */

222

if (mc.current_server == NULL){

260

if(*current_server == NULL){

223

261

new_server->next = new_server;

224

262

new_server->prev = new_server;

225

mc.current_server = new_server;

226

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

263

*current_server = new_server;

227

264

} else {

228

new_server->next = mc.current_server;

229

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

265

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

266

new_server->next = *current_server;

267

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

230

268

new_server->prev->next = new_server;

231

mc.current_server->prev = new_server;

232

}

233

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

234

if(ret == -1){

235

perror_plus("clock_gettime");

236

return -1;

237

}

238

return 0;

269

(*current_server)->prev = new_server;

270

}

271

return true;

239

272

}

240

273

241

274

/*

242

275

* Initialize GPGME.

243

276

*/

244

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

245

const char *tempdir){

277

__attribute__((nonnull, warn_unused_result))

278

static bool init_gpgme(const char * const seckey,

279

const char * const pubkey,

280

const char * const tempdir,

281

mandos_context *mc){

246

282

gpgme_error_t rc;

247

283

gpgme_engine_info_t engine_info;

248

284

249

250

285

/*

251

286

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

252

287

*/

253

bool import_key(const char *filename){

288

bool import_key(const char * const filename){

254

289

int ret;

255

290

int fd;

256

291

gpgme_data_t pgp_data;

268

303

return false;

269

304

}

270

305

271

rc = gpgme_op_import(mc.ctx, pgp_data);

306

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

272

307

if(rc != GPG_ERR_NO_ERROR){

273

308

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

274

309

gpgme_strsource(rc), gpgme_strerror(rc));

275

310

return false;

276

311

}

277

312

278

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

313

ret = close(fd);

279

314

if(ret == -1){

280

315

perror_plus("close");

281

316

}

318

353

}

319

354

320

355

/* Create new GPGME "context" */

321

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

356

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

322

357

if(rc != GPG_ERR_NO_ERROR){

323

358

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

324

359

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

337

372

* Decrypt OpenPGP data.

338

373

* Returns -1 on error

339

374

*/

375

__attribute__((nonnull, warn_unused_result))

340

376

static ssize_t pgp_packet_decrypt(const char *cryptotext,

341

377

size_t crypto_size,

342

char **plaintext){

378

char **plaintext,

379

mandos_context *mc){

343

380

gpgme_data_t dh_crypto, dh_plain;

344

381

gpgme_error_t rc;

345

382

ssize_t ret;

371

408

372

409

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

373

410

data buffer */

374

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

411

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

375

412

if(rc != GPG_ERR_NO_ERROR){

376

413

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

377

414

gpgme_strsource(rc), gpgme_strerror(rc));

378

415

plaintext_length = -1;

379

416

if(debug){

380

417

gpgme_decrypt_result_t result;

381

result = gpgme_op_decrypt_result(mc.ctx);

418

result = gpgme_op_decrypt_result(mc->ctx);

382

419

if(result == NULL){

383

420

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

384

421

} else {

461

498

return plaintext_length;

462

499

}

463

500

464

static const char * safer_gnutls_strerror(int value){

465

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

466

-Wunreachable-code */

467

if(ret == NULL)

468

ret = "(unknown)";

469

return ret;

501

__attribute__((warn_unused_result, const))

502

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

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

508

__attribute__((warn_unused_result))

509

static const char *safer_gnutls_strerror(int value){

510

const char *ret = gnutls_strerror(value);

511

return safe_string(ret);

470

512

}

471

513

472

514

/* GnuTLS log function callback */

515

__attribute__((nonnull))

473

516

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

474

517

const char* string){

475

518

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

476

519

}

477

520

521

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

478

522

static int init_gnutls_global(const char *pubkeyfilename,

479

const char *seckeyfilename){

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

525

mandos_context *mc){

480

526

int ret;

527

unsigned int uret;

481

528

482

529

if(debug){

483

530

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

484

531

}

485

532

486

ret = gnutls_global_init();

487

if(ret != GNUTLS_E_SUCCESS){

488

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

489

safer_gnutls_strerror(ret));

490

return -1;

491

}

492

493

533

if(debug){

494

534

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

495

535

* - GnuTLS manual

499

539

}

500

540

501

541

/* OpenPGP credentials */

502

ret = gnutls_certificate_allocate_credentials(&mc.cred);

542

ret = gnutls_certificate_allocate_credentials(&mc->cred);

503

543

if(ret != GNUTLS_E_SUCCESS){

504

544

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

505

545

safer_gnutls_strerror(ret));

506

gnutls_global_deinit();

507

546

return -1;

508

547

}

509

548

515

554

}

516

555

517

556

ret = gnutls_certificate_set_openpgp_key_file

518

(mc.cred, pubkeyfilename, seckeyfilename,

557

(mc->cred, pubkeyfilename, seckeyfilename,

519

558

GNUTLS_OPENPGP_FMT_BASE64);

520

559

if(ret != GNUTLS_E_SUCCESS){

521

560

fprintf_plus(stderr,

527

566

}

528

567

529

568

/* GnuTLS server initialization */

530

ret = gnutls_dh_params_init(&mc.dh_params);

569

ret = gnutls_dh_params_init(&mc->dh_params);

531

570

if(ret != GNUTLS_E_SUCCESS){

532

571

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

533

572

" initialization: %s\n",

534

573

safer_gnutls_strerror(ret));

535

574

goto globalfail;

536

575

}

537

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

538

if(ret != GNUTLS_E_SUCCESS){

539

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

540

safer_gnutls_strerror(ret));

541

goto globalfail;

542

}

543

544

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

576

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

577

if(dhparamsfilename != NULL){

578

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

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

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

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

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

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

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

625

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

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

free(params.data);

630

} while(false);

631

}

632

if(dhparamsfilename == NULL){

633

if(mc->dh_bits == 0){

634

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

635

/* Try to read the private key file */

636

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

637

do {

638

int secfile = open(seckeyfilename, O_RDONLY);

639

if(secfile == -1){

640

perror_plus("open");

641

break;

642

}

643

size_t buffer_capacity = 0;

644

while(true){

645

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

646

(size_t)buffer.size,

647

(size_t)buffer_capacity);

648

if(buffer_capacity == 0){

649

perror_plus("incbuffer");

650

free(buffer.data);

651

buffer.data = NULL;

652

break;

653

}

654

ssize_t bytes_read = read(secfile,

655

buffer.data + buffer.size,

656

BUFFER_SIZE);

657

/* EOF */

658

if(bytes_read == 0){

659

break;

660

}

661

/* check bytes_read for failure */

662

if(bytes_read < 0){

663

perror_plus("read");

664

free(buffer.data);

665

buffer.data = NULL;

666

break;

667

}

668

buffer.size += (unsigned int)bytes_read;

669

}

670

close(secfile);

671

} while(false);

672

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

673

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

674

if(buffer.data != NULL){

675

{

676

gnutls_openpgp_privkey_t privkey = NULL;

677

ret = gnutls_openpgp_privkey_init(&privkey);

678

if(ret != GNUTLS_E_SUCCESS){

679

fprintf_plus(stderr, "Error initializing OpenPGP key"

680

" structure: %s",

681

safer_gnutls_strerror(ret));

682

free(buffer.data);

683

buffer.data = NULL;

684

} else {

685

ret = gnutls_openpgp_privkey_import

686

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

687

if(ret != GNUTLS_E_SUCCESS){

688

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

689

safer_gnutls_strerror(ret));

690

privkey = NULL;

691

}

692

free(buffer.data);

693

buffer.data = NULL;

694

if(privkey != NULL){

695

/* Use private key to suggest an appropriate

696

sec_param */

697

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

698

gnutls_openpgp_privkey_deinit(privkey);

699

if(debug){

700

fprintf_plus(stderr, "This OpenPGP key implies using"

701

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

702

safe_string(gnutls_sec_param_get_name

703

(sec_param)));

704

}

705

}

706

}

707

}

708

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

709

/* Err on the side of caution */

710

sec_param = GNUTLS_SEC_PARAM_ULTRA;

711

if(debug){

712

fprintf_plus(stderr, "Falling back to security parameter"

713

" \"%s\"\n",

714

safe_string(gnutls_sec_param_get_name

715

(sec_param)));

716

}

717

}

718

}

719

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

720

if(uret != 0){

721

mc->dh_bits = uret;

722

if(debug){

723

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

724

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

725

safe_string(gnutls_sec_param_get_name

726

(sec_param)),

727

mc->dh_bits);

728

}

729

} else {

730

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

731

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

732

safe_string(gnutls_sec_param_get_name

733

(sec_param)),

734

safer_gnutls_strerror(ret));

735

goto globalfail;

736

}

737

} else if(debug){

738

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

739

mc->dh_bits);

740

}

741

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

742

if(ret != GNUTLS_E_SUCCESS){

743

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

744

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

745

safer_gnutls_strerror(ret));

746

goto globalfail;

747

}

748

}

749

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

545

750

546

751

return 0;

547

752

548

753

globalfail:

549

754

550

gnutls_certificate_free_credentials(mc.cred);

551

gnutls_global_deinit();

552

gnutls_dh_params_deinit(mc.dh_params);

755

gnutls_certificate_free_credentials(mc->cred);

756

gnutls_dh_params_deinit(mc->dh_params);

553

757

return -1;

554

758

}

555

759

556

static int init_gnutls_session(gnutls_session_t *session){

760

__attribute__((nonnull, warn_unused_result))

761

static int init_gnutls_session(gnutls_session_t *session,

762

mandos_context *mc){

557

763

int ret;

558

764

/* GnuTLS session creation */

559

765

do {

571

777

{

572

778

const char *err;

573

779

do {

574

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

780

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

575

781

if(quit_now){

576

782

gnutls_deinit(*session);

577

783

return -1;

588

794

589

795

do {

590

796

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

591

mc.cred);

797

mc->cred);

592

798

if(quit_now){

593

799

gnutls_deinit(*session);

594

800

return -1;

604

810

/* ignore client certificate if any. */

605

811

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

606

812

607

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

608

609

813

return 0;

610

814

}

611

815

613

817

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

614

818

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

615

819

820

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

821

__attribute__((warn_unused_result))

822

int raise_privileges(void){

823

int old_errno = errno;

824

int ret = 0;

825

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

826

ret = errno;

827

}

828

errno = old_errno;

829

return ret;

830

}

831

832

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

833

__attribute__((warn_unused_result))

834

int raise_privileges_permanently(void){

835

int old_errno = errno;

836

int ret = raise_privileges();

837

if(ret != 0){

838

errno = old_errno;

839

return ret;

840

}

841

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

842

ret = errno;

843

}

844

errno = old_errno;

845

return ret;

846

}

847

848

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

849

__attribute__((warn_unused_result))

850

int lower_privileges(void){

851

int old_errno = errno;

852

int ret = 0;

853

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

854

ret = errno;

855

}

856

errno = old_errno;

857

return ret;

858

}

859

860

/* Lower privileges permanently */

861

__attribute__((warn_unused_result))

862

int lower_privileges_permanently(void){

863

int old_errno = errno;

864

int ret = 0;

865

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

866

ret = errno;

867

}

868

errno = old_errno;

869

return ret;

870

}

871

872

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

873

__attribute__((nonnull, warn_unused_result))

874

static bool add_delete_local_route(const bool add,

875

const char *address,

876

AvahiIfIndex if_index){

877

int ret;

878

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

879

char add_arg[] = "add";

880

char delete_arg[] = "delete";

881

char debug_flag[] = "--debug";

882

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

883

if(pluginhelperdir == NULL){

884

if(debug){

885

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

886

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

887

}

888

return false;

889

}

890

891

char interface[IF_NAMESIZE];

892

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

893

perror_plus("if_indextoname");

894

return false;

895

}

896

897

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

898

if(devnull == -1){

899

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

900

return false;

901

}

902

pid_t pid = fork();

903

if(pid == 0){

904

/* Child */

905

/* Raise privileges */

906

errno = raise_privileges_permanently();

907

if(errno != 0){

908

perror_plus("Failed to raise privileges");

909

/* _exit(EX_NOPERM); */

910

} else {

911

/* Set group */

912

errno = 0;

913

ret = setgid(0);

914

if(ret == -1){

915

perror_plus("setgid");

916

_exit(EX_NOPERM);

917

}

918

/* Reset supplementary groups */

919

errno = 0;

920

ret = setgroups(0, NULL);

921

if(ret == -1){

922

perror_plus("setgroups");

923

_exit(EX_NOPERM);

924

}

925

}

926

ret = dup2(devnull, STDIN_FILENO);

927

if(ret == -1){

928

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

929

_exit(EX_OSERR);

930

}

931

ret = close(devnull);

932

if(ret == -1){

933

perror_plus("close");

934

_exit(EX_OSERR);

935

}

936

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

937

if(ret == -1){

938

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

939

_exit(EX_OSERR);

940

}

941

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

942

O_RDONLY

943

| O_DIRECTORY

944

| O_PATH

945

| O_CLOEXEC));

946

if(helperdir_fd == -1){

947

perror_plus("open");

948

_exit(EX_UNAVAILABLE);

949

}

950

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

951

helper, O_RDONLY));

952

if(helper_fd == -1){

953

perror_plus("openat");

954

close(helperdir_fd);

955

_exit(EX_UNAVAILABLE);

956

}

957

close(helperdir_fd);

958

#ifdef __GNUC__

959

#pragma GCC diagnostic push

960

#pragma GCC diagnostic ignored "-Wcast-qual"

961

#endif

962

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

963

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

964

interface, debug ? debug_flag : NULL, NULL },

965

environ) == -1){

966

#ifdef __GNUC__

967

#pragma GCC diagnostic pop

968

#endif

969

perror_plus("fexecve");

970

_exit(EXIT_FAILURE);

971

}

972

}

973

if(pid == -1){

974

perror_plus("fork");

975

return false;

976

}

977

int status;

978

pid_t pret = -1;

979

errno = 0;

980

do {

981

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

982

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

983

int errno_raising = 0;

984

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

985

errno_raising = errno;

986

perror_plus("Failed to raise privileges in order to"

987

" kill helper program");

988

}

989

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

990

perror_plus("kill");

991

}

992

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

993

perror_plus("Failed to lower privileges after killing"

994

" helper program");

995

}

996

return false;

997

}

998

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

999

if(pret == -1){

1000

perror_plus("waitpid");

1001

return false;

1002

}

1003

if(WIFEXITED(status)){

1004

if(WEXITSTATUS(status) != 0){

1005

fprintf_plus(stderr, "Error: iprouteadddel exited"

1006

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

1007

return false;

1008

}

1009

return true;

1010

}

1011

if(WIFSIGNALED(status)){

1012

fprintf_plus(stderr, "Error: iprouteadddel died by"

1013

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

1014

return false;

1015

}

1016

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

1017

return false;

1018

}

1019

1020

__attribute__((nonnull, warn_unused_result))

1021

static bool add_local_route(const char *address,

1022

AvahiIfIndex if_index){

1023

if(debug){

1024

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

1025

}

1026

return add_delete_local_route(true, address, if_index);

1027

}

1028

1029

__attribute__((nonnull, warn_unused_result))

1030

static bool delete_local_route(const char *address,

1031

AvahiIfIndex if_index){

1032

if(debug){

1033

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

1034

}

1035

return add_delete_local_route(false, address, if_index);

1036

}

1037

616

1038

/* Called when a Mandos server is found */

617

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

1039

__attribute__((nonnull, warn_unused_result))

1040

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

618

1041

AvahiIfIndex if_index,

619

int af){

1042

int af, mandos_context *mc){

620

1043

int ret, tcp_sd = -1;

621

1044

ssize_t sret;

622

union {

623

struct sockaddr_in in;

624

struct sockaddr_in6 in6;

625

} to;

1045

struct sockaddr_storage to;

626

1046

char *buffer = NULL;

627

1047

char *decrypted_buffer = NULL;

628

1048

size_t buffer_length = 0;

631

1051

int retval = -1;

632

1052

gnutls_session_t session;

633

1053

int pf; /* Protocol family */

1054

bool route_added = false;

634

1055

635

1056

errno = 0;

636

1057

652

1073

return -1;

653

1074

}

654

1075

655

ret = init_gnutls_session(&session);

1076

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

1077

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

1078

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

1079

bool match = false;

1080

{

1081

char *interface = NULL;

1082

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

1083

mc->interfaces_size,

1084

interface))){

1085

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

1086

match = true;

1087

break;

1088

}

1089

}

1090

}

1091

if(not match){

1092

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

1093

connect to the server */

1094

if(debug){

1095

char interface[IF_NAMESIZE];

1096

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

1097

perror_plus("if_indextoname");

1098

} else {

1099

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

1100

" \"%s\"\n",

1101

if_indextoname((unsigned int)if_index,

1102

interface));

1103

}

1104

}

1105

return -1;

1106

}

1107

}

1108

1109

ret = init_gnutls_session(&session, mc);

656

1110

if(ret != 0){

657

1111

return -1;

658

1112

}

659

1113

660

1114

if(debug){

661

1115

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

662

PRIu16 "\n", ip, port);

1116

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

663

1117

}

664

1118

665

tcp_sd = socket(pf, SOCK_STREAM, 0);

1119

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

666

1120

if(tcp_sd < 0){

667

1121

int e = errno;

668

1122

perror_plus("socket");

675

1129

goto mandos_end;

676

1130

}

677

1131

678

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

679

1132

if(af == AF_INET6){

680

to.in6.sin6_family = (sa_family_t)af;

681

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

1133

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

1134

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

1135

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

682

1136

} else { /* IPv4 */

683

to.in.sin_family = (sa_family_t)af;

684

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

1137

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

1138

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

1139

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

685

1140

}

686

1141

if(ret < 0 ){

687

1142

int e = errno;

696

1151

goto mandos_end;

697

1152

}

698

1153

if(af == AF_INET6){

699

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

700

-Wconversion and

701

-Wunreachable-code */

702

703

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

704

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

705

-Wunreachable-code*/

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

706

1157

if(if_index == AVAHI_IF_UNSPEC){

707

1158

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

708

1159

" incomplete without a network interface\n");

710

1161

goto mandos_end;

711

1162

}

712

1163

/* Set the network interface number as scope */

713

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

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

714

1165

}

715

1166

} else {

716

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

717

-Wconversion and

718

-Wunreachable-code */

1167

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

719

1168

}

720

1169

721

1170

if(quit_now){

729

1178

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

730

1179

perror_plus("if_indextoname");

731

1180

} else {

732

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

733

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

1181

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

1182

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

734

1183

}

735

1184

} else {

736

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

737

ip, port);

1185

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

1186

ip, (uintmax_t)port);

738

1187

}

739

1188

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

740

1189

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

741

const char *pcret;

742

if(af == AF_INET6){

743

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

744

sizeof(addrstr));

745

} else {

746

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

747

sizeof(addrstr));

748

}

749

if(pcret == NULL){

750

perror_plus("inet_ntop");

751

} else {

752

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

753

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

754

}

755

}

756

}

757

758

if(quit_now){

759

errno = EINTR;

760

goto mandos_end;

761

}

762

763

if(af == AF_INET6){

764

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

765

} else {

766

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

767

}

768

if(ret < 0){

769

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

770

int e = errno;

771

perror_plus("connect");

772

errno = e;

773

}

774

goto mandos_end;

775

}

776

777

if(quit_now){

778

errno = EINTR;

779

goto mandos_end;

1190

if(af == AF_INET6){

1191

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

1192

sizeof(struct sockaddr_in6),

1193

addrstr, sizeof(addrstr), NULL, 0,

1194

NI_NUMERICHOST);

1195

} else {

1196

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

1197

sizeof(struct sockaddr_in),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

}

1201

if(ret == EAI_SYSTEM){

1202

perror_plus("getnameinfo");

1203

} else if(ret != 0) {

1204

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

1205

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

1206

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

1207

}

1208

}

1209

1210

if(quit_now){

1211

errno = EINTR;

1212

goto mandos_end;

1213

}

1214

1215

while(true){

1216

if(af == AF_INET6){

1217

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

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

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

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

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

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

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

1234

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

1235

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

1236

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

1237

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

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

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

1241

1242

Avahi bug reference:

1243

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

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

780

1270

}

781

1271

782

1272

const char *out = mandos_protocol_version;

818

1308

goto mandos_end;

819

1309

}

820

1310

821

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

822

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1311

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

1312

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

1313

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

1314

gnutls_transport_set_ptr(session,

1315

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

823

1316

824

1317

if(quit_now){

825

1318

errno = EINTR;

930

1423

if(buffer_length > 0){

931

1424

ssize_t decrypted_buffer_size;

932

1425

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

933

&decrypted_buffer);

1426

&decrypted_buffer, mc);

934

1427

if(decrypted_buffer_size >= 0){

935

1428

1429

clearerr(stdout);

936

1430

written = 0;

937

1431

while(written < (size_t) decrypted_buffer_size){

938

1432

if(quit_now){

954

1448

}

955

1449

written += (size_t)ret;

956

1450

}

1451

ret = fflush(stdout);

1452

if(ret != 0){

1453

int e = errno;

1454

if(debug){

1455

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

1456

strerror(errno));

1457

}

1458

errno = e;

1459

goto mandos_end;

1460

}

957

1461

retval = 0;

958

1462

}

959

1463

}

962

1466

963

1467

mandos_end:

964

1468

{

1469

if(route_added){

1470

if(not delete_local_route(ip, if_index)){

1471

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

1472

" interface %d", ip, if_index);

1473

}

1474

}

965

1475

int e = errno;

966

1476

free(decrypted_buffer);

967

1477

free(buffer);

968

1478

if(tcp_sd >= 0){

969

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

1479

ret = close(tcp_sd);

970

1480

}

971

1481

if(ret == -1){

972

1482

if(e == 0){

984

1494

return retval;

985

1495

}

986

1496

1497

__attribute__((nonnull))

987

1498

static void resolve_callback(AvahiSServiceResolver *r,

988

1499

AvahiIfIndex interface,

989

1500

AvahiProtocol proto,

997

1508

AVAHI_GCC_UNUSED AvahiStringList *txt,

998

1509

AVAHI_GCC_UNUSED AvahiLookupResultFlags

999

1510

flags,

1000

AVAHI_GCC_UNUSED void* userdata){

1001

assert(r);

1511

void *mc){

1512

if(r == NULL){

1513

return;

1514

}

1002

1515

1003

1516

/* Called whenever a service has been resolved successfully or

1004

1517

timed out */

1005

1518

1006

1519

if(quit_now){

1520

avahi_s_service_resolver_free(r);

1007

1521

return;

1008

1522

}

1009

1523

1013

1527

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

1014

1528

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

1015

1529

domain,

1016

avahi_strerror(avahi_server_errno(mc.server)));

1530

avahi_strerror(avahi_server_errno

1531

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

1017

1532

break;

1018

1533

1019

1534

case AVAHI_RESOLVER_FOUND:

1025

1540

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

1026

1541

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

1027

1542

}

1028

int ret = start_mandos_communication(ip, port, interface,

1029

avahi_proto_to_af(proto));

1543

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

1544

interface,

1545

avahi_proto_to_af(proto),

1546

mc);

1030

1547

if(ret == 0){

1031

avahi_simple_poll_quit(mc.simple_poll);

1548

avahi_simple_poll_quit(simple_poll);

1032

1549

} else {

1033

ret = add_server(ip, port, interface,

1034

avahi_proto_to_af(proto));

1550

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

1551

avahi_proto_to_af(proto),

1552

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

1553

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

1554

" list\n", name);

1555

}

1035

1556

}

1036

1557

}

1037

1558

}

1047

1568

const char *domain,

1048

1569

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1049

1570

flags,

1050

AVAHI_GCC_UNUSED void* userdata){

1051

assert(b);

1571

void *mc){

1572

if(b == NULL){

1573

return;

1574

}

1052

1575

1053

1576

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

1054

1577

is removed from the LAN */

1062

1585

case AVAHI_BROWSER_FAILURE:

1063

1586

1064

1587

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

1065

avahi_strerror(avahi_server_errno(mc.server)));

1066

avahi_simple_poll_quit(mc.simple_poll);

1588

avahi_strerror(avahi_server_errno

1589

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

1590

avahi_simple_poll_quit(simple_poll);

1067

1591

return;

1068

1592

1069

1593

case AVAHI_BROWSER_NEW:

1072

1596

the callback function is called the Avahi server will free the

1073

1597

resolver for us. */

1074

1598

1075

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

1076

name, type, domain, protocol, 0,

1077

resolve_callback, NULL) == NULL)

1599

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

1600

interface, protocol, name, type,

1601

domain, protocol, 0,

1602

resolve_callback, mc) == NULL)

1078

1603

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

1079

1604

" %s\n", name,

1080

avahi_strerror(avahi_server_errno(mc.server)));

1605

avahi_strerror(avahi_server_errno

1606

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

1081

1607

break;

1082

1608

1083

1609

case AVAHI_BROWSER_REMOVE:

1102

1628

signal_received = sig;

1103

1629

int old_errno = errno;

1104

1630

/* set main loop to exit */

1105

if(mc.simple_poll != NULL){

1106

avahi_simple_poll_quit(mc.simple_poll);

1631

if(simple_poll != NULL){

1632

avahi_simple_poll_quit(simple_poll);

1107

1633

}

1108

1634

errno = old_errno;

1109

1635

}

1110

1636

1637

__attribute__((nonnull, warn_unused_result))

1111

1638

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

1112

1639

int ret;

1640

int old_errno;

1113

1641

1114

1642

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

1115

1643

if(s < 0){

1644

old_errno = errno;

1116

1645

perror_plus("socket");

1646

errno = old_errno;

1117

1647

return false;

1118

1648

}

1119

strcpy(ifr->ifr_name, ifname);

1649

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

1650

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

1120

1651

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1121

1652

if(ret == -1){

1122

1653

if(debug){

1654

old_errno = errno;

1123

1655

perror_plus("ioctl SIOCGIFFLAGS");

1656

errno = old_errno;

1124

1657

}

1125

1658

return false;

1126

1659

}

1127

1660

return true;

1128

1661

}

1129

1662

1663

__attribute__((nonnull, warn_unused_result))

1130

1664

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

1131

1665

1132

1666

/* Reject the loopback device */

1174

1708

* corresponds to an acceptable network device.

1175

1709

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

1176

1710

*/

1711

__attribute__((nonnull, warn_unused_result))

1177

1712

int good_interface(const struct dirent *if_entry){

1178

1713

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

1179

1714

return 0;

1195

1730

}

1196

1731

1197

1732

/*

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

1733

* This function determines if a network interface is up.

1734

*/

1735

__attribute__((nonnull, warn_unused_result))

1736

bool interface_is_up(const char *interface){

1737

struct ifreq ifr;

1738

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

1739

if(debug){

1740

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

1741

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

1742

}

1743

return false;

1744

}

1745

1746

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

1747

}

1748

1749

/*

1750

* This function determines if a network interface is running

1751

*/

1752

__attribute__((nonnull, warn_unused_result))

1753

bool interface_is_running(const char *interface){

1754

struct ifreq ifr;

1755

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

1756

if(debug){

1757

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

1758

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

1759

}

1760

return false;

1761

}

1762

1763

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

1764

}

1765

1766

__attribute__((nonnull, pure, warn_unused_result))

1240

1767

int notdotentries(const struct dirent *direntry){

1241

1768

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

1242

1769

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

1249

1776

}

1250

1777

1251

1778

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

1779

__attribute__((nonnull, warn_unused_result))

1252

1780

int runnable_hook(const struct dirent *direntry){

1253

1781

int ret;

1254

1782

size_t sret;

1262

1790

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

1263

1791

"abcdefghijklmnopqrstuvwxyz"

1264

1792

"0123456789"

1265

"_-");

1793

"_.-");

1266

1794

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

1267

1795

/* Contains non-allowed characters */

1268

1796

if(debug){

1272

1800

return 0;

1273

1801

}

1274

1802

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);

1803

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

1283

1804

if(ret == -1){

1284

1805

if(debug){

1285

1806

perror_plus("Could not stat hook");

1309

1830

return 1;

1310

1831

}

1311

1832

1312

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1833

__attribute__((nonnull, warn_unused_result))

1834

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1835

mandos_context *mc){

1313

1836

int ret;

1314

1837

struct timespec now;

1315

1838

struct timespec waited_time;

1316

1839

intmax_t block_time;

1317

1840

1318

1841

while(true){

1319

if(mc.current_server == NULL){

1320

if (debug){

1842

if(mc->current_server == NULL){

1843

if(debug){

1321

1844

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

1322

1845

" No timeout!\n");

1323

1846

}

1324

1847

ret = avahi_simple_poll_iterate(s, -1);

1325

1848

} else {

1326

if (debug){

1849

if(debug){

1327

1850

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

1328

1851

" it, or wait\n");

1329

1852

}

1336

1859

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

1337

1860

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

1338

1861

waited_time.tv_sec = (now.tv_sec

1339

- mc.current_server->last_seen.tv_sec);

1862

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

1340

1863

waited_time.tv_nsec = (now.tv_nsec

1341

- mc.current_server->last_seen.tv_nsec);

1864

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

1342

1865

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

1343

1866

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

1344

1867

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

1346

1869

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

1347

1870

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

1348

1871

1349

if (debug){

1872

if(debug){

1350

1873

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

1351

1874

block_time);

1352

1875

}

1353

1876

1354

1877

if(block_time <= 0){

1355

ret = start_mandos_communication(mc.current_server->ip,

1356

mc.current_server->port,

1357

mc.current_server->if_index,

1358

mc.current_server->af);

1878

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

1879

mc->current_server->port,

1880

mc->current_server->if_index,

1881

mc->current_server->af, mc);

1359

1882

if(ret == 0){

1360

avahi_simple_poll_quit(mc.simple_poll);

1883

avahi_simple_poll_quit(s);

1361

1884

return 0;

1362

1885

}

1363

1886

ret = clock_gettime(CLOCK_MONOTONIC,

1364

&mc.current_server->last_seen);

1887

&mc->current_server->last_seen);

1365

1888

if(ret == -1){

1366

1889

perror_plus("clock_gettime");

1367

1890

return -1;

1368

1891

}

1369

mc.current_server = mc.current_server->next;

1892

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

1370

1893

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

1371

1894

servers, but don't block */

1372

1895

}

1374

1897

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

1375

1898

}

1376

1899

if(ret != 0){

1377

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

1900

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

1378

1901

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

1379

1902

}

1380

1903

}

1381

1904

}

1382

1905

}

1383

1906

1384

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

1907

__attribute__((nonnull))

1908

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

1385

1909

const float delay){

1386

struct dirent **direntries;

1387

struct dirent *direntry;

1388

int ret;

1389

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

1390

alphasort);

1910

struct dirent **direntries = NULL;

1911

if(hookdir_fd == -1){

1912

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1913

| O_CLOEXEC);

1914

if(hookdir_fd == -1){

1915

if(errno == ENOENT){

1916

if(debug){

1917

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

1918

" found\n", hookdir);

1919

}

1920

} else {

1921

perror_plus("open");

1922

}

1923

return;

1924

}

1925

}

1926

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

1927

runnable_hook, alphasort);

1391

1928

if(numhooks == -1){

1392

1929

perror_plus("scandir");

1393

} else {

1394

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

1395

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

1396

direntry = direntries[i];

1397

char *fullname = NULL;

1398

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

1399

if(ret < 0){

1930

return;

1931

}

1932

struct dirent *direntry;

1933

int ret;

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1939

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

1940

direntry = direntries[i];

1941

if(debug){

1942

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

1943

direntry->d_name);

1944

}

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

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

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

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

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

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

1990

if(ret == -1){

1400

1991

perror_plus("asprintf");

1401

continue;

1402

}

1403

if(debug){

1404

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

1405

direntry->d_name);

1406

}

1407

pid_t hook_pid = fork();

1408

if(hook_pid == 0){

1409

/* Child */

1410

/* Raise privileges */

1411

errno = 0;

1412

ret = seteuid(0);

1413

if(ret == -1){

1414

perror_plus("seteuid");

1415

}

1416

/* Raise privileges even more */

1417

errno = 0;

1418

ret = setuid(0);

1419

if(ret == -1){

1420

perror_plus("setuid");

1421

}

1422

/* Set group */

1423

errno = 0;

1424

ret = setgid(0);

1425

if(ret == -1){

1426

perror_plus("setgid");

1427

}

1428

/* Reset supplementary groups */

1429

errno = 0;

1430

ret = setgroups(0, NULL);

1431

if(ret == -1){

1432

perror_plus("setgroups");

1433

}

1434

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

}

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1469

1996

free(delaystring);

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;

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

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

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

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

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

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

2054

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

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

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

2061

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

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

2065

} else {

2066

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

2067

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

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

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

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

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

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

2085

}

2086

2087

__attribute__((nonnull, warn_unused_result))

2088

int bring_up_interface(const char *const interface,

2089

const float delay){

2090

int old_errno = errno;

2091

int ret;

2092

struct ifreq network;

2093

unsigned int if_index = if_nametoindex(interface);

2094

if(if_index == 0){

2095

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

2096

errno = old_errno;

2097

return ENXIO;

2098

}

2099

2100

if(quit_now){

2101

errno = old_errno;

2102

return EINTR;

2103

}

2104

2105

if(not interface_is_up(interface)){

2106

int ret_errno = 0;

2107

int ioctl_errno = 0;

2108

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

2109

ret_errno = errno;

2110

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

2111

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

2112

errno = old_errno;

2113

return ret_errno;

2114

}

2115

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

2116

2117

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

2118

if(sd == -1){

2119

ret_errno = errno;

2120

perror_plus("socket");

2121

errno = old_errno;

2122

return ret_errno;

2123

}

2124

2125

if(quit_now){

2126

ret = close(sd);

2127

if(ret == -1){

2128

perror_plus("close");

2129

}

2130

errno = old_errno;

2131

return EINTR;

2132

}

2133

2134

if(debug){

2135

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

2136

interface);

2137

}

2138

2139

/* Raise privileges */

2140

ret_errno = raise_privileges();

2141

if(ret_errno != 0){

2142

errno = ret_errno;

2143

perror_plus("Failed to raise privileges");

2144

}

2145

2146

#ifdef __linux__

2147

int ret_linux;

2148

bool restore_loglevel = false;

2149

if(ret_errno == 0){

2150

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2151

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

2152

ret_linux = klogctl(8, NULL, 5);

2153

if(ret_linux == -1){

2154

perror_plus("klogctl");

2155

} else {

2156

restore_loglevel = true;

2157

}

2158

}

2159

#endif /* __linux__ */

2160

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

2161

ioctl_errno = errno;

2162

#ifdef __linux__

2163

if(restore_loglevel){

2164

ret_linux = klogctl(7, NULL, 0);

2165

if(ret_linux == -1){

2166

perror_plus("klogctl");

2167

}

2168

}

2169

#endif /* __linux__ */

2170

2171

/* If raise_privileges() succeeded above */

2172

if(ret_errno == 0){

2173

/* Lower privileges */

2174

ret_errno = lower_privileges();

2175

if(ret_errno != 0){

2176

errno = ret_errno;

2177

perror_plus("Failed to lower privileges");

2178

}

2179

}

2180

2181

/* Close the socket */

2182

ret = close(sd);

2183

if(ret == -1){

2184

perror_plus("close");

2185

}

2186

2187

if(ret_setflags == -1){

2188

errno = ioctl_errno;

2189

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2190

errno = old_errno;

2191

return ioctl_errno;

2192

}

2193

} else if(debug){

2194

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

2195

interface);

2196

}

2197

2198

/* Sleep checking until interface is running.

2199

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

2200

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

2201

if(interface_is_running(interface)){

2202

break;

2203

}

2204

struct timespec sleeptime = { .tv_nsec = 250000000 };

2205

ret = nanosleep(&sleeptime, NULL);

2206

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

2207

perror_plus("nanosleep");

2208

}

2209

}

2210

2211

errno = old_errno;

2212

return 0;

2213

}

2214

2215

__attribute__((nonnull, warn_unused_result))

2216

int take_down_interface(const char *const interface){

2217

int old_errno = errno;

2218

struct ifreq network;

2219

unsigned int if_index = if_nametoindex(interface);

2220

if(if_index == 0){

2221

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

2222

errno = old_errno;

2223

return ENXIO;

2224

}

2225

if(interface_is_up(interface)){

2226

int ret_errno = 0;

2227

int ioctl_errno = 0;

2228

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

2229

ret_errno = errno;

2230

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

2231

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

2232

errno = old_errno;

2233

return ret_errno;

2234

}

2235

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

2236

2237

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

2238

if(sd == -1){

2239

ret_errno = errno;

2240

perror_plus("socket");

2241

errno = old_errno;

2242

return ret_errno;

2243

}

2244

2245

if(debug){

2246

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

2247

interface);

2248

}

2249

2250

/* Raise privileges */

2251

ret_errno = raise_privileges();

2252

if(ret_errno != 0){

2253

errno = ret_errno;

2254

perror_plus("Failed to raise privileges");

2255

}

2256

2257

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

2258

ioctl_errno = errno;

2259

2260

/* If raise_privileges() succeeded above */

2261

if(ret_errno == 0){

2262

/* Lower privileges */

2263

ret_errno = lower_privileges();

2264

if(ret_errno != 0){

2265

errno = ret_errno;

2266

perror_plus("Failed to lower privileges");

2267

}

2268

}

2269

2270

/* Close the socket */

2271

int ret = close(sd);

2272

if(ret == -1){

2273

perror_plus("close");

2274

}

2275

2276

if(ret_setflags == -1){

2277

errno = ioctl_errno;

2278

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2279

errno = old_errno;

2280

return ioctl_errno;

2281

}

2282

} else if(debug){

2283

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

2284

interface);

2285

}

2286

2287

errno = old_errno;

2288

return 0;

1509

2289

}

1510

2290

1511

2291

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

2292

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

2293

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

2294

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

2295

.current_server = NULL, .interfaces = NULL,

2296

.interfaces_size = 0 };

1512

2297

AvahiSServiceBrowser *sb = NULL;

1513

int error;

2298

error_t ret_errno;

1514

2299

int ret;

1515

2300

intmax_t tmpmax;

1516

2301

char *tmp;

1517

2302

int exitcode = EXIT_SUCCESS;

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;

2303

char *interfaces_to_take_down = NULL;

2304

size_t interfaces_to_take_down_size = 0;

2305

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

2306

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

2307

char *tempdir = NULL;

1526

2308

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1527

2309

const char *seckey = PATHDIR "/" SECKEY;

1528

2310

const char *pubkey = PATHDIR "/" PUBKEY;

2311

const char *dh_params_file = NULL;

2312

char *interfaces_hooks = NULL;

1529

2313

1530

2314

bool gnutls_initialized = false;

1531

2315

bool gpgme_initialized = false;

1583

2367

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

1584

2368

" Diffie-Hellman key exchange",

1585

2369

.group = 2 },

2370

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

2371

.arg = "FILE",

2372

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

2373

" for the Diffie-Hellman key exchange",

2374

.group = 2 },

1586

2375

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

1587

2376

.arg = "STRING",

1588

2377

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

1593

2382

.group = 2 },

1594

2383

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

1595

2384

.arg = "SECONDS",

1596

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

2385

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

1597

2386

.group = 2 },

1598

2387

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

1599

2388

.arg = "DIR",

1622

2411

connect_to = arg;

1623

2412

break;

1624

2413

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

1625

interface = arg;

2414

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

2415

arg, (int)',');

2416

if(ret_errno != 0){

2417

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

2418

}

1626

2419

break;

1627

2420

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

1628

2421

seckey = arg;

1639

2432

}

1640

2433

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

1641

2434

break;

2435

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

2436

dh_params_file = arg;

2437

break;

1642

2438

case 130: /* --priority */

1643

2439

mc.priority = arg;

1644

2440

break;

1671

2467

argp_state_help(state, state->out_stream,

1672

2468

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1673

2469

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

1674

fprintf_plus(state->out_stream,

1675

"Mandos plugin mandos-client: ");

1676

2470

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

1677

2471

exit(argp_err_exit_status);

1678

2472

break;

1686

2480

.args_doc = "",

1687

2481

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

1688

2482

" passwords from a Mandos server" };

1689

ret = argp_parse(&argp, argc, argv,

1690

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1691

switch(ret){

2483

ret_errno = argp_parse(&argp, argc, argv,

2484

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2485

switch(ret_errno){

1692

2486

case 0:

1693

2487

break;

1694

2488

case ENOMEM:

1695

2489

default:

1696

errno = ret;

2490

errno = ret_errno;

1697

2491

perror_plus("argp_parse");

1698

2492

exitcode = EX_OSERR;

1699

2493

goto end;

1702

2496

goto end;

1703

2497

}

1704

2498

}

1705

2499

1706

2500

{

1707

2501

/* Work around Debian bug #633582:

1708

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

2502

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

1709

2503

1710

/* Re-raise priviliges */

1711

errno = 0;

1712

ret = seteuid(0);

1713

if(ret == -1){

1714

perror_plus("seteuid");

2504

/* Re-raise privileges */

2505

ret = raise_privileges();

2506

if(ret != 0){

2507

errno = ret;

2508

perror_plus("Failed to raise privileges");

1715

2509

} else {

1716

2510

struct stat st;

1717

2511

1732

2526

}

1733

2527

}

1734

2528

}

1735

TEMP_FAILURE_RETRY(close(seckey_fd));

2529

close(seckey_fd);

1736

2530

}

1737

2531

}

1738

2532

1739

2533

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

1740

2534

int pubkey_fd = open(pubkey, O_RDONLY);

1741

2535

if(pubkey_fd == -1){

1753

2547

}

1754

2548

}

1755

2549

}

1756

TEMP_FAILURE_RETRY(close(pubkey_fd));

1757

}

1758

}

1759

2550

close(pubkey_fd);

2551

}

2552

}

2553

2554

if(dh_params_file != NULL

2555

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

2556

int dhparams_fd = open(dh_params_file, O_RDONLY);

2557

if(dhparams_fd == -1){

2558

perror_plus("open");

2559

} else {

2560

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

2561

if(ret == -1){

2562

perror_plus("fstat");

2563

} else {

2564

if(S_ISREG(st.st_mode)

2565

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

2566

ret = fchown(dhparams_fd, uid, gid);

2567

if(ret == -1){

2568

perror_plus("fchown");

2569

}

2570

}

2571

}

2572

close(dhparams_fd);

2573

}

2574

}

2575

1760

2576

/* Lower privileges */

1761

errno = 0;

1762

ret = seteuid(uid);

1763

if(ret == -1){

1764

perror_plus("seteuid");

2577

ret = lower_privileges();

2578

if(ret != 0){

2579

errno = ret;

2580

perror_plus("Failed to lower privileges");

2581

}

2582

}

2583

}

2584

2585

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

2586

{

2587

char *interface = NULL;

2588

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

2589

interface))){

2590

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

2591

and if_nametoindex(interface) == 0){

2592

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

2593

fprintf_plus(stderr, "Not using nonexisting interface"

2594

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

2595

}

2596

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

2597

interface = NULL;

1765

2598

}

1766

2599

}

1767

2600

}

1768

2601

1769

2602

/* Run network hooks */

1770

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

1771

goto end;

2603

{

2604

if(mc.interfaces != NULL){

2605

interfaces_hooks = malloc(mc.interfaces_size);

2606

if(interfaces_hooks == NULL){

2607

perror_plus("malloc");

2608

goto end;

2609

}

2610

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

2611

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

2612

}

2613

run_network_hooks("start", interfaces_hooks != NULL ?

2614

interfaces_hooks : "", delay);

1772

2615

}

1773

2616

1774

2617

if(not debug){

1775

2618

avahi_set_log_function(empty_log);

1776

2619

}

1777

2620

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

1810

2621

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

1811

2622

from the signal handler */

1812

2623

/* Initialize the pseudo-RNG for Avahi */

1813

2624

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

1814

mc.simple_poll = avahi_simple_poll_new();

1815

if(mc.simple_poll == NULL){

2625

simple_poll = avahi_simple_poll_new();

2626

if(simple_poll == NULL){

1816

2627

fprintf_plus(stderr,

1817

2628

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

1818

2629

exitcode = EX_UNAVAILABLE;

1882

2693

}

1883

2694

}

1884

2695

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");

2696

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

2697

if(mc.interfaces == NULL){

2698

struct dirent **direntries = NULL;

2699

/* Look for any good interfaces */

2700

ret = scandir(sys_class_net, &direntries, good_interface,

2701

alphasort);

2702

if(ret >= 1){

2703

/* Add all found interfaces to interfaces list */

2704

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

2705

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

2706

direntries[i]->d_name);

2707

if(ret_errno != 0){

2708

errno = ret_errno;

2709

perror_plus("argz_add");

2710

free(direntries[i]);

2711

continue;

2712

}

2713

if(debug){

2714

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

2715

direntries[i]->d_name);

2716

}

2717

free(direntries[i]);

2718

}

2719

free(direntries);

2720

} else {

2721

if(ret == 0){

2722

free(direntries);

2723

}

2724

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

2725

exitcode = EXIT_FAILURE;

2726

goto end;

2727

}

2728

}

2729

2730

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

2731

{

2732

char *interface = NULL;

2733

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

2734

interface))){

2735

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

2736

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

2737

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

2738

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

2739

interface);

2740

interface = NULL;

2741

while((interface = argz_next(mc.interfaces,

2742

mc.interfaces_size, interface))){

2743

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

2744

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

2745

interface);

2746

interface = NULL;

1970

2747

}

1971

2748

}

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){

1989

2749

break;

1990

2750

}

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

}

2751

bool interface_was_up = interface_is_up(interface);

2752

errno = bring_up_interface(interface, delay);

2753

if(not interface_was_up){

2754

if(errno != 0){

2755

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

2756

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

2757

} else {

2758

errno = argz_add(&interfaces_to_take_down,

2759

&interfaces_to_take_down_size,

2760

interface);

2761

if(errno != 0){

2762

perror_plus("argz_add");

2763

}

2764

}

2765

}

2766

}

2767

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

2768

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

2769

}

2770

}

2771

2772

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

2773

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

2774

if(debug){

2775

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

2776

mc.interfaces);

2777

}

2778

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

2020

2779

}

2021

2780

2022

2781

if(quit_now){

2023

2782

goto end;

2024

2783

}

2025

2784

2026

ret = init_gnutls_global(pubkey, seckey);

2785

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

2027

2786

if(ret == -1){

2028

2787

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

2029

2788

exitcode = EX_UNAVAILABLE;

2036

2795

goto end;

2037

2796

}

2038

2797

2039

if(mkdtemp(tempdir) == NULL){

2798

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

2799

tempdir = mkdtemp(run_tempdir);

2800

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

2801

if(debug){

2802

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

2803

run_tempdir, old_tempdir);

2804

}

2805

tempdir = mkdtemp(old_tempdir);

2806

}

2807

if(tempdir == NULL){

2040

2808

perror_plus("mkdtemp");

2041

2809

goto end;

2042

2810

}

2043

tempdir_created = true;

2044

2811

2045

2812

if(quit_now){

2046

2813

goto end;

2047

2814

}

2048

2815

2049

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

2816

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

2050

2817

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

2051

2818

exitcode = EX_UNAVAILABLE;

2052

2819

goto end;

2062

2829

/* Connect directly, do not use Zeroconf */

2063

2830

/* (Mainly meant for debugging) */

2064

2831

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

2832

2065

2833

if(address == NULL){

2066

2834

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

2067

2835

exitcode = EX_USAGE;

2072

2840

goto end;

2073

2841

}

2074

2842

2075

uint16_t port;

2843

in_port_t port;

2076

2844

errno = 0;

2077

2845

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

2078

2846

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

2079

or tmpmax != (uint16_t)tmpmax){

2847

or tmpmax != (in_port_t)tmpmax){

2080

2848

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

2081

2849

exitcode = EX_USAGE;

2082

2850

goto end;

2083

2851

}

2084

2852

2085

2853

if(quit_now){

2086

2854

goto end;

2087

2855

}

2088

2856

2089

port = (uint16_t)tmpmax;

2857

port = (in_port_t)tmpmax;

2090

2858

*address = '\0';

2091

2859

/* Colon in address indicates IPv6 */

2092

2860

int af;

2108

2876

}

2109

2877

2110

2878

while(not quit_now){

2111

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

2879

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

2880

&mc);

2112

2881

if(quit_now or ret == 0){

2113

2882

break;

2114

2883

}

2116

2885

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

2117

2886

(int)retry_interval);

2118

2887

}

2119

sleep((int)retry_interval);

2888

sleep((unsigned int)retry_interval);

2120

2889

}

2121

2890

2122

if (not quit_now){

2891

if(not quit_now){

2123

2892

exitcode = EXIT_SUCCESS;

2124

2893

}

2125

2894

2140

2909

config.publish_domain = 0;

2141

2910

2142

2911

/* Allocate a new server */

2143

mc.server = avahi_server_new(avahi_simple_poll_get

2144

(mc.simple_poll), &config, NULL,

2145

NULL, &error);

2912

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2913

&config, NULL, NULL, &ret);

2146

2914

2147

2915

/* Free the Avahi configuration data */

2148

2916

avahi_server_config_free(&config);

2151

2919

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

2152

2920

if(mc.server == NULL){

2153

2921

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

2154

avahi_strerror(error));

2922

avahi_strerror(ret));

2155

2923

exitcode = EX_UNAVAILABLE;

2156

2924

goto end;

2157

2925

}

2163

2931

/* Create the Avahi service browser */

2164

2932

sb = avahi_s_service_browser_new(mc.server, if_index,

2165

2933

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2166

NULL, 0, browse_callback, NULL);

2934

NULL, 0, browse_callback,

2935

(void *)&mc);

2167

2936

if(sb == NULL){

2168

2937

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

2169

2938

avahi_strerror(avahi_server_errno(mc.server)));

2180

2949

if(debug){

2181

2950

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

2182

2951

}

2183

2184

ret = avahi_loop_with_timeout(mc.simple_poll,

2185

(int)(retry_interval * 1000));

2952

2953

ret = avahi_loop_with_timeout(simple_poll,

2954

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

2186

2955

if(debug){

2187

2956

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

2188

2957

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

2191

2960

end:

2192

2961

2193

2962

if(debug){

2194

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

2963

if(signal_received){

2964

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

2965

argv[0], signal_received,

2966

strsignal(signal_received));

2967

} else {

2968

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

2969

}

2195

2970

}

2196

2971

2197

2972

/* Cleanup things */

2973

free(mc.interfaces);

2974

2198

2975

if(sb != NULL)

2199

2976

avahi_s_service_browser_free(sb);

2200

2977

2201

2978

if(mc.server != NULL)

2202

2979

avahi_server_free(mc.server);

2203

2980

2204

if(mc.simple_poll != NULL)

2205

avahi_simple_poll_free(mc.simple_poll);

2981

if(simple_poll != NULL)

2982

avahi_simple_poll_free(simple_poll);

2206

2983

2207

2984

if(gnutls_initialized){

2208

2985

gnutls_certificate_free_credentials(mc.cred);

2209

gnutls_global_deinit();

2210

2986

gnutls_dh_params_deinit(mc.dh_params);

2211

2987

}

2212

2988

2220

2996

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

2221

2997

while(mc.current_server != NULL){

2222

2998

server *next = mc.current_server->next;

2999

#ifdef __GNUC__

3000

#pragma GCC diagnostic push

3001

#pragma GCC diagnostic ignored "-Wcast-qual"

3002

#endif

3003

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

3004

#ifdef __GNUC__

3005

#pragma GCC diagnostic pop

3006

#endif

2223

3007

free(mc.current_server);

2224

3008

mc.current_server = next;

2225

3009

}

2226

3010

}

2227

3011

2228

/* Run network hooks */

2229

run_network_hooks("stop", interface, delay);

2230

2231

/* Re-raise priviliges */

3012

/* Re-raise privileges */

2232

3013

{

2233

errno = 0;

2234

ret = seteuid(0);

2235

if(ret == -1){

2236

perror_plus("seteuid");

3014

ret = raise_privileges();

3015

if(ret != 0){

3016

errno = ret;

3017

perror_plus("Failed to raise privileges");

3018

} else {

3019

3020

/* Run network hooks */

3021

run_network_hooks("stop", interfaces_hooks != NULL ?

3022

interfaces_hooks : "", delay);

3023

3024

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

3025

{

3026

char *interface = NULL;

3027

while((interface = argz_next(interfaces_to_take_down,

3028

interfaces_to_take_down_size,

3029

interface))){

3030

ret = take_down_interface(interface);

3031

if(ret != 0){

3032

errno = ret;

3033

perror_plus("Failed to take down interface");

3034

}

3035

}

3036

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

3037

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

3038

" down\n");

3039

}

3040

}

2237

3041

}

2238

3042

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

}

3043

ret = lower_privileges_permanently();

3044

if(ret != 0){

3045

errno = ret;

3046

perror_plus("Failed to lower privileges permanently");

2255

3047

}

2256

3048

}

2257

/* Lower privileges permanently */

2258

errno = 0;

2259

ret = setuid(uid);

2260

if(ret == -1){

2261

perror_plus("setuid");

3049

3050

free(interfaces_to_take_down);

3051

free(interfaces_hooks);

3052

3053

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

3054

uintmax_t level){

3055

struct dirent **direntries = NULL;

3056

int dret;

3057

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

3058

O_RDONLY

3059

| O_NOFOLLOW

3060

| O_DIRECTORY

3061

| O_PATH));

3062

if(dir_fd == -1){

3063

perror_plus("open");

3064

}

3065

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

3066

notdotentries, alphasort);

3067

if(numentries >= 0){

3068

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

3069

if(debug){

3070

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

3071

dirname, direntries[i]->d_name);

3072

}

3073

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

3074

if(dret == -1){

3075

if(errno == EISDIR){

3076

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

3077

AT_REMOVEDIR);

3078

}

3079

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

3080

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

3081

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

3082

/* Recurse only in this special case */

3083

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

3084

dret = 0;

3085

}

3086

if(dret == -1){

3087

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

3088

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

3089

}

3090

}

3091

free(direntries[i]);

3092

}

3093

3094

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

3095

free(direntries);

3096

if(numentries == -1){

3097

perror_plus("scandirat");

3098

}

3099

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3100

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

3101

perror_plus("rmdir");

3102

}

3103

} else {

3104

perror_plus("scandirat");

3105

}

3106

close(dir_fd);

2262

3107

}

2263

3108

2264

3109

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

2265

if(tempdir_created){

2266

struct dirent **direntries = NULL;

2267

struct dirent *direntry = NULL;

2268

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

2269

alphasort);

2270

if (numentries > 0){

2271

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

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

}

3110

if(tempdir != NULL){

3111

clean_dir_at(-1, tempdir, 0);

2298

3112

}

2299

3113

2300

3114

if(quit_now){