/mandos/trunk : revision 594

9

* "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

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#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

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#endif

36

#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

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#endif /* not _FILE_OFFSET_BITS */

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#endif

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40

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

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

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stdout, ferror() */

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stdout, ferror(), remove() */

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

45

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

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

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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() */

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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

*/

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

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63

strtoimax() */

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

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

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program_invocation_short_name */

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

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*/

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#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() */

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

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

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

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

80

79

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

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argp_state, struct argp,

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

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WEXITSTATUS(), WTERMSIG() */

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

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

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argz_delete(), argz_append(),

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argz_stringify(), argz_add(),

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argz_count() */

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

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EAI_SYSTEM, gai_strerror() */

98

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92

#ifdef __linux__

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93

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

142

135

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

143

136

char *connect_to = NULL;

144

137

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

uid_t uid = 65534;

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gid_t gid = 65534;

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138

149

139

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

150

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typedef struct server{

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141

const char *ip;

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in_port_t port;

142

uint16_t port;

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143

AvahiIfIndex if_index;

154

144

int af;

155

145

struct timespec last_seen;

159

149

160

150

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

161

151

typedef struct {

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AvahiSimplePoll *simple_poll;

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153

AvahiServer *server;

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gnutls_certificate_credentials_t cred;

164

155

unsigned int dh_bits;

166

157

const char *priority;

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158

gpgme_ctx_t ctx;

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159

server *current_server;

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char *interfaces;

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size_t interfaces_size;

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160

} mandos_context;

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161

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/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

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

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

164

.dh_bits = 1024, .priority = "SECURE256"

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

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.current_server = NULL };

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167

176

168

sig_atomic_t quit_now = 0;

177

169

int signal_received = 0;

185

177

perror(print_text);

186

178

}

187

179

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

180

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

189

181

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

190

182

va_list ap;

191

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va_start (ap, format);

192

184

193

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

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186

program_invocation_short_name));

195

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

187

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

196

188

}

197

189

198

190

/*

200

192

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

201

193

* "buffer_length" is how much is already used.

202

194

*/

203

__attribute__((nonnull, warn_unused_result))

204

195

size_t incbuffer(char **buffer, size_t buffer_length,

205

196

size_t buffer_capacity){

206

197

if(buffer_length + BUFFER_SIZE > buffer_capacity){

207

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

208

if(new_buf == NULL){

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int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

198

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

199

if(buffer == NULL){

213

200

return 0;

214

201

}

215

*buffer = new_buf;

216

202

buffer_capacity += BUFFER_SIZE;

217

203

}

218

204

return buffer_capacity;

219

205

}

220

206

221

207

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

222

__attribute__((nonnull, warn_unused_result))

223

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

224

int af, server **current_server){

208

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

209

int af){

225

210

int ret;

226

211

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

227

212

if(new_server == NULL){

234

219

.af = af };

235

220

if(new_server->ip == NULL){

236

221

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

222

return false;

253

223

}

254

224

/* Special case of first server */

255

if(*current_server == NULL){

225

if (mc.current_server == NULL){

256

226

new_server->next = new_server;

257

227

new_server->prev = new_server;

258

*current_server = new_server;

228

mc.current_server = new_server;

229

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

259

230

} else {

260

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

261

new_server->next = *current_server;

262

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

231

new_server->next = mc.current_server;

232

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

263

233

new_server->prev->next = new_server;

264

(*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;

265

240

}

266

241

return true;

267

242

}

269

244

/*

270

245

* Initialize GPGME.

271

246

*/

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

247

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

248

const char *tempdir){

277

249

gpgme_error_t rc;

278

250

gpgme_engine_info_t engine_info;

279

251

252

280

253

/*

281

254

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

282

255

*/

283

bool import_key(const char * const filename){

256

bool import_key(const char *filename){

284

257

int ret;

285

258

int fd;

286

259

gpgme_data_t pgp_data;

298

271

return false;

299

272

}

300

273

301

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

274

rc = gpgme_op_import(mc.ctx, pgp_data);

302

275

if(rc != GPG_ERR_NO_ERROR){

303

276

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

304

277

gpgme_strsource(rc), gpgme_strerror(rc));

348

321

}

349

322

350

323

/* Create new GPGME "context" */

351

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

324

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

352

325

if(rc != GPG_ERR_NO_ERROR){

353

326

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

354

327

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

367

340

* Decrypt OpenPGP data.

368

341

* Returns -1 on error

369

342

*/

370

__attribute__((nonnull, warn_unused_result))

371

343

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

344

size_t crypto_size,

373

char **plaintext,

374

mandos_context *mc){

345

char **plaintext){

375

346

gpgme_data_t dh_crypto, dh_plain;

376

347

gpgme_error_t rc;

377

348

ssize_t ret;

403

374

404

375

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

405

376

data buffer */

406

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

377

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

407

378

if(rc != GPG_ERR_NO_ERROR){

408

379

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

409

380

gpgme_strsource(rc), gpgme_strerror(rc));

410

381

plaintext_length = -1;

411

382

if(debug){

412

383

gpgme_decrypt_result_t result;

413

result = gpgme_op_decrypt_result(mc->ctx);

384

result = gpgme_op_decrypt_result(mc.ctx);

414

385

if(result == NULL){

415

386

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

416

387

} else {

493

464

return plaintext_length;

494

465

}

495

466

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

505

const char *ret = gnutls_strerror(value);

506

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;

507

473

}

508

474

509

475

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

476

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

512

477

const char* string){

513

478

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

514

479

}

515

480

516

__attribute__((nonnull, warn_unused_result))

517

481

static int init_gnutls_global(const char *pubkeyfilename,

518

const char *seckeyfilename,

519

mandos_context *mc){

482

const char *seckeyfilename){

520

483

int ret;

521

unsigned int uret;

522

484

523

485

if(debug){

524

486

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

540

502

}

541

503

542

504

/* OpenPGP credentials */

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

544

506

if(ret != GNUTLS_E_SUCCESS){

545

507

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

546

508

safer_gnutls_strerror(ret));

556

518

}

557

519

558

520

ret = gnutls_certificate_set_openpgp_key_file

559

(mc->cred, pubkeyfilename, seckeyfilename,

521

(mc.cred, pubkeyfilename, seckeyfilename,

560

522

GNUTLS_OPENPGP_FMT_BASE64);

561

523

if(ret != GNUTLS_E_SUCCESS){

562

524

fprintf_plus(stderr,

568

530

}

569

531

570

532

/* GnuTLS server initialization */

571

ret = gnutls_dh_params_init(&mc->dh_params);

533

ret = gnutls_dh_params_init(&mc.dh_params);

572

534

if(ret != GNUTLS_E_SUCCESS){

573

535

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

574

536

" initialization: %s\n",

575

537

safer_gnutls_strerror(ret));

576

538

goto globalfail;

577

539

}

578

if(mc->dh_bits == 0){

579

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

580

/* Try to read the private key file */

581

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

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

585

while(true){

586

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

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

590

perror_plus("incbuffer");

591

free(buffer.data);

592

buffer.data = NULL;

593

break;

594

}

595

ssize_t bytes_read = read(secfile, buffer.data + buffer.size,

596

BUFFER_SIZE);

597

/* EOF */

598

if(bytes_read == 0){

599

break;

600

}

601

/* check bytes_read for failure */

602

if(bytes_read < 0){

603

perror_plus("read");

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

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

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

" structure: %s", safer_gnutls_strerror(ret));

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

627

if(ret != GNUTLS_E_SUCCESS){

628

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

629

safer_gnutls_strerror(ret));

630

privkey = NULL;

631

}

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

/* Use private key to suggest an appropriate sec_param */

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

fprintf_plus(stderr, "This OpenPGP key implies using a"

640

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

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

644

}

645

}

646

}

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

650

if(debug){

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

653

safe_string(gnutls_sec_param_get_name

654

(sec_param)));

655

}

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

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

663

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

664

safe_string(gnutls_sec_param_get_name

665

(sec_param)),

666

mc->dh_bits);

667

}

668

} else {

669

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

670

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

671

safe_string(gnutls_sec_param_get_name(sec_param)),

672

safer_gnutls_strerror(ret));

673

goto globalfail;

674

}

675

} else if(debug){

676

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

677

mc->dh_bits);

678

}

679

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

540

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

680

541

if(ret != GNUTLS_E_SUCCESS){

681

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

682

" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));

542

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

543

safer_gnutls_strerror(ret));

683

544

goto globalfail;

684

545

}

685

546

686

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

547

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

687

548

688

549

return 0;

689

550

690

551

globalfail:

691

552

692

gnutls_certificate_free_credentials(mc->cred);

553

gnutls_certificate_free_credentials(mc.cred);

693

554

gnutls_global_deinit();

694

gnutls_dh_params_deinit(mc->dh_params);

555

gnutls_dh_params_deinit(mc.dh_params);

695

556

return -1;

696

557

}

697

558

698

__attribute__((nonnull, warn_unused_result))

699

static int init_gnutls_session(gnutls_session_t *session,

700

mandos_context *mc){

559

static int init_gnutls_session(gnutls_session_t *session){

701

560

int ret;

702

561

/* GnuTLS session creation */

703

562

do {

715

574

{

716

575

const char *err;

717

576

do {

718

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

577

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

719

578

if(quit_now){

720

579

gnutls_deinit(*session);

721

580

return -1;

732

591

733

592

do {

734

593

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

735

mc->cred);

594

mc.cred);

736

595

if(quit_now){

737

596

gnutls_deinit(*session);

738

597

return -1;

748

607

/* ignore client certificate if any. */

749

608

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

750

609

751

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

752

611

753

612

return 0;

754

613

}

757

616

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

758

617

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

759

618

760

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

761

__attribute__((warn_unused_result))

762

error_t raise_privileges(void){

763

error_t old_errno = errno;

764

error_t ret_errno = 0;

765

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

766

ret_errno = errno;

767

}

768

errno = old_errno;

769

return ret_errno;

770

}

771

772

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

773

__attribute__((warn_unused_result))

774

error_t raise_privileges_permanently(void){

775

error_t old_errno = errno;

776

error_t ret_errno = raise_privileges();

777

if(ret_errno != 0){

778

errno = old_errno;

779

return ret_errno;

780

}

781

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

782

ret_errno = errno;

783

}

784

errno = old_errno;

785

return ret_errno;

786

}

787

788

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

789

__attribute__((warn_unused_result))

790

error_t lower_privileges(void){

791

error_t old_errno = errno;

792

error_t ret_errno = 0;

793

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

794

ret_errno = errno;

795

}

796

errno = old_errno;

797

return ret_errno;

798

}

799

800

/* Lower privileges permanently */

801

__attribute__((warn_unused_result))

802

error_t lower_privileges_permanently(void){

803

error_t old_errno = errno;

804

error_t ret_errno = 0;

805

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

806

ret_errno = errno;

807

}

808

errno = old_errno;

809

return ret_errno;

810

}

811

812

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

813

__attribute__((nonnull, warn_unused_result))

814

static bool add_delete_local_route(const bool add,

815

const char *address,

816

AvahiIfIndex if_index){

817

int ret;

818

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

819

char add_arg[] = "add";

820

char delete_arg[] = "delete";

821

char debug_flag[] = "--debug";

822

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

823

if(pluginhelperdir == NULL){

824

if(debug){

825

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

826

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

827

}

828

return false;

829

}

830

831

char interface[IF_NAMESIZE];

832

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

833

perror_plus("if_indextoname");

834

return false;

835

}

836

837

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

838

if(devnull == -1){

839

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

840

return false;

841

}

842

pid_t pid = fork();

843

if(pid == 0){

844

/* Child */

845

/* Raise privileges */

846

errno = raise_privileges_permanently();

847

if(errno != 0){

848

perror_plus("Failed to raise privileges");

849

/* _exit(EX_NOPERM); */

850

} else {

851

/* Set group */

852

errno = 0;

853

ret = setgid(0);

854

if(ret == -1){

855

perror_plus("setgid");

856

_exit(EX_NOPERM);

857

}

858

/* Reset supplementary groups */

859

errno = 0;

860

ret = setgroups(0, NULL);

861

if(ret == -1){

862

perror_plus("setgroups");

863

_exit(EX_NOPERM);

864

}

865

}

866

ret = dup2(devnull, STDIN_FILENO);

867

if(ret == -1){

868

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

869

_exit(EX_OSERR);

870

}

871

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

872

if(ret == -1){

873

perror_plus("close");

874

_exit(EX_OSERR);

875

}

876

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

877

if(ret == -1){

878

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

879

_exit(EX_OSERR);

880

}

881

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

882

O_RDONLY

883

| O_DIRECTORY

884

| O_PATH

885

| O_CLOEXEC));

886

if(helperdir_fd == -1){

887

perror_plus("open");

888

_exit(EX_UNAVAILABLE);

889

}

890

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

891

helper, O_RDONLY));

892

if(helper_fd == -1){

893

perror_plus("openat");

894

_exit(EX_UNAVAILABLE);

895

}

896

TEMP_FAILURE_RETRY(close(helperdir_fd));

897

#ifdef __GNUC__

898

#pragma GCC diagnostic push

899

#pragma GCC diagnostic ignored "-Wcast-qual"

900

#endif

901

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

902

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

903

interface, debug ? debug_flag : NULL, NULL },

904

environ) == -1){

905

#ifdef __GNUC__

906

#pragma GCC diagnostic pop

907

#endif

908

perror_plus("fexecve");

909

_exit(EXIT_FAILURE);

910

}

911

}

912

if(pid == -1){

913

perror_plus("fork");

914

return false;

915

}

916

int status;

917

pid_t pret = -1;

918

errno = 0;

919

do {

920

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

921

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

922

int errno_raising = 0;

923

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

924

errno_raising = errno;

925

perror_plus("Failed to raise privileges in order to"

926

" kill helper program");

927

}

928

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

929

perror_plus("kill");

930

}

931

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

932

perror_plus("Failed to lower privileges after killing"

933

" helper program");

934

}

935

return false;

936

}

937

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

938

if(pret == -1){

939

perror_plus("waitpid");

940

return false;

941

}

942

if(WIFEXITED(status)){

943

if(WEXITSTATUS(status) != 0){

944

fprintf_plus(stderr, "Error: iprouteadddel exited"

945

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

946

return false;

947

}

948

return true;

949

}

950

if(WIFSIGNALED(status)){

951

fprintf_plus(stderr, "Error: iprouteadddel died by"

952

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

953

return false;

954

}

955

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

956

return false;

957

}

958

959

__attribute__((nonnull, warn_unused_result))

960

static bool add_local_route(const char *address,

961

AvahiIfIndex if_index){

962

if(debug){

963

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

964

}

965

return add_delete_local_route(true, address, if_index);

966

}

967

968

__attribute__((nonnull, warn_unused_result))

969

static bool delete_local_route(const char *address,

970

AvahiIfIndex if_index){

971

if(debug){

972

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

973

}

974

return add_delete_local_route(false, address, if_index);

975

}

976

977

619

/* Called when a Mandos server is found */

978

__attribute__((nonnull, warn_unused_result))

979

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

620

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

980

621

AvahiIfIndex if_index,

981

int af, mandos_context *mc){

622

int af){

982

623

int ret, tcp_sd = -1;

983

624

ssize_t sret;

984

struct sockaddr_storage to;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

985

629

char *buffer = NULL;

986

630

char *decrypted_buffer = NULL;

987

631

size_t buffer_length = 0;

990

634

int retval = -1;

991

635

gnutls_session_t session;

992

636

int pf; /* Protocol family */

993

bool route_added = false;

994

637

995

638

errno = 0;

996

639

1012

655

return -1;

1013

656

}

1014

657

1015

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

1016

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

1017

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

1018

bool match = false;

1019

{

1020

char *interface = NULL;

1021

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

1022

interface))){

1023

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

1024

match = true;

1025

break;

1026

}

1027

}

1028

}

1029

if(not match){

1030

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

1031

connect to the server */

1032

if(debug){

1033

char interface[IF_NAMESIZE];

1034

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

1035

perror_plus("if_indextoname");

1036

} else {

1037

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

1038

" \"%s\"\n",

1039

if_indextoname((unsigned int)if_index,

1040

interface));

1041

}

1042

}

1043

return -1;

1044

}

1045

}

1046

1047

ret = init_gnutls_session(&session, mc);

658

ret = init_gnutls_session(&session);

1048

659

if(ret != 0){

1049

660

return -1;

1050

661

}

1051

662

1052

663

if(debug){

1053

664

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

1054

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

665

PRIu16 "\n", ip, port);

1055

666

}

1056

667

1057

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

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1058

669

if(tcp_sd < 0){

1059

670

int e = errno;

1060

671

perror_plus("socket");

1069

680

1070

681

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

1071

682

if(af == AF_INET6){

1072

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

1073

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

683

to.in6.sin6_family = (sa_family_t)af;

684

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

1074

685

} else { /* IPv4 */

1075

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

1076

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

686

to.in.sin_family = (sa_family_t)af;

687

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

1077

688

}

1078

689

if(ret < 0 ){

1079

690

int e = errno;

1088

699

goto mandos_end;

1089

700

}

1090

701

if(af == AF_INET6){

1091

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

1092

if(IN6_IS_ADDR_LINKLOCAL

1093

(&((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*/

1094

709

if(if_index == AVAHI_IF_UNSPEC){

1095

710

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

1096

711

" incomplete without a network interface\n");

1098

713

goto mandos_end;

1099

714

}

1100

715

/* Set the network interface number as scope */

1101

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

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1102

717

}

1103

718

} else {

1104

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

719

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

720

-Wconversion and

721

-Wunreachable-code */

1105

722

}

1106

723

1107

724

if(quit_now){

1115

732

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

1116

733

perror_plus("if_indextoname");

1117

734

} else {

1118

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

1119

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

735

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

736

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

1120

737

}

1121

738

} else {

1122

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

1123

ip, (uintmax_t)port);

739

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

740

ip, port);

1124

741

}

1125

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1126

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1127

if(af == AF_INET6){

1128

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

1129

sizeof(struct sockaddr_in6),

1130

addrstr, sizeof(addrstr), NULL, 0,

1131

NI_NUMERICHOST);

1132

} else {

1133

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

1134

sizeof(struct sockaddr_in),

1135

addrstr, sizeof(addrstr), NULL, 0,

1136

NI_NUMERICHOST);

1137

}

1138

if(ret == EAI_SYSTEM){

1139

perror_plus("getnameinfo");

1140

} else if(ret != 0) {

1141

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

1142

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

1143

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

1144

}

1145

}

1146

1147

if(quit_now){

1148

errno = EINTR;

1149

goto mandos_end;

1150

}

1151

1152

while(true){

1153

if(af == AF_INET6){

1154

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

1155

sizeof(struct sockaddr_in6));

1156

} else {

1157

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

1158

sizeof(struct sockaddr_in));

1159

}

1160

if(ret < 0){

1161

if(errno == ENETUNREACH

1162

and if_index != AVAHI_IF_UNSPEC

1163

and connect_to == NULL

1164

and not route_added and

1165

((af == AF_INET6 and not

1166

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1167

&to)->sin6_addr)))

1168

or (af == AF_INET and

1169

/* Not a a IPv4LL address */

1170

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

1171

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

1172

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

1173

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

1174

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

1175

connect to a Mandos server announced by Avahi on a server

1176

host with a global address. Work around this by retrying

1177

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

1178

1179

Avahi bug reference:

1180

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

1181

https://bugs.debian.org/587961

1182

*/

1183

if(debug){

1184

fprintf_plus(stderr, "Mandos server unreachable, trying"

1185

" direct route\n");

1186

}

1187

int e = errno;

1188

route_added = add_local_route(ip, if_index);

1189

if(route_added){

1190

continue;

1191

}

1192

errno = e;

1193

}

1194

if(errno != ECONNREFUSED or debug){

1195

int e = errno;

1196

perror_plus("connect");

1197

errno = e;

1198

}

1199

goto mandos_end;

1200

}

1201

1202

if(quit_now){

1203

errno = EINTR;

1204

goto mandos_end;

1205

}

1206

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;

1207

783

}

1208

784

1209

785

const char *out = mandos_protocol_version;

1360

936

if(buffer_length > 0){

1361

937

ssize_t decrypted_buffer_size;

1362

938

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1363

&decrypted_buffer, mc);

939

&decrypted_buffer);

1364

940

if(decrypted_buffer_size >= 0){

1365

941

1366

942

written = 0;

1392

968

1393

969

mandos_end:

1394

970

{

1395

if(route_added){

1396

if(not delete_local_route(ip, if_index)){

1397

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

1398

" interface %d", ip, if_index);

1399

}

1400

}

1401

971

int e = errno;

1402

972

free(decrypted_buffer);

1403

973

free(buffer);

1420

990

return retval;

1421

991

}

1422

992

1423

__attribute__((nonnull))

1424

993

static void resolve_callback(AvahiSServiceResolver *r,

1425

994

AvahiIfIndex interface,

1426

995

AvahiProtocol proto,

1434

1003

AVAHI_GCC_UNUSED AvahiStringList *txt,

1435

1004

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1436

1005

flags,

1437

void *mc){

1438

if(r == NULL){

1439

return;

1440

}

1006

AVAHI_GCC_UNUSED void* userdata){

1007

assert(r);

1441

1008

1442

1009

/* Called whenever a service has been resolved successfully or

1443

1010

timed out */

1444

1011

1445

1012

if(quit_now){

1446

avahi_s_service_resolver_free(r);

1447

1013

return;

1448

1014

}

1449

1015

1453

1019

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

1454

1020

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

1455

1021

domain,

1456

avahi_strerror(avahi_server_errno

1457

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

1022

avahi_strerror(avahi_server_errno(mc.server)));

1458

1023

break;

1459

1024

1460

1025

case AVAHI_RESOLVER_FOUND:

1466

1031

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

1467

1032

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

1468

1033

}

1469

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

1470

interface,

1471

avahi_proto_to_af(proto),

1472

mc);

1034

int ret = start_mandos_communication(ip, port, interface,

1035

avahi_proto_to_af(proto));

1473

1036

if(ret == 0){

1474

avahi_simple_poll_quit(simple_poll);

1037

avahi_simple_poll_quit(mc.simple_poll);

1475

1038

} else {

1476

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

1477

avahi_proto_to_af(proto),

1478

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

1039

if(not add_server(ip, port, interface,

1040

avahi_proto_to_af(proto))){

1479

1041

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

1480

1042

" list\n", name);

1481

1043

}

1494

1056

const char *domain,

1495

1057

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1496

1058

flags,

1497

void *mc){

1498

if(b == NULL){

1499

return;

1500

}

1059

AVAHI_GCC_UNUSED void* userdata){

1060

assert(b);

1501

1061

1502

1062

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

1503

1063

is removed from the LAN */

1511

1071

case AVAHI_BROWSER_FAILURE:

1512

1072

1513

1073

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

1514

avahi_strerror(avahi_server_errno

1515

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

1516

avahi_simple_poll_quit(simple_poll);

1074

avahi_strerror(avahi_server_errno(mc.server)));

1075

avahi_simple_poll_quit(mc.simple_poll);

1517

1076

return;

1518

1077

1519

1078

case AVAHI_BROWSER_NEW:

1522

1081

the callback function is called the Avahi server will free the

1523

1082

resolver for us. */

1524

1083

1525

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

1526

interface, protocol, name, type,

1527

domain, protocol, 0,

1528

resolve_callback, mc) == NULL)

1084

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

1085

name, type, domain, protocol, 0,

1086

resolve_callback, NULL) == NULL)

1529

1087

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

1530

1088

" %s\n", name,

1531

avahi_strerror(avahi_server_errno

1532

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

1089

avahi_strerror(avahi_server_errno(mc.server)));

1533

1090

break;

1534

1091

1535

1092

case AVAHI_BROWSER_REMOVE:

1554

1111

signal_received = sig;

1555

1112

int old_errno = errno;

1556

1113

/* set main loop to exit */

1557

if(simple_poll != NULL){

1558

avahi_simple_poll_quit(simple_poll);

1114

if(mc.simple_poll != NULL){

1115

avahi_simple_poll_quit(mc.simple_poll);

1559

1116

}

1560

1117

errno = old_errno;

1561

1118

}

1562

1119

1563

__attribute__((nonnull, warn_unused_result))

1564

1120

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

1565

1121

int ret;

1566

error_t ret_errno;

1567

1122

1568

1123

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

1569

1124

if(s < 0){

1570

ret_errno = errno;

1571

1125

perror_plus("socket");

1572

errno = ret_errno;

1573

1126

return false;

1574

1127

}

1575

1128

strcpy(ifr->ifr_name, ifname);

1576

1129

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1577

1130

if(ret == -1){

1578

1131

if(debug){

1579

ret_errno = errno;

1580

1132

perror_plus("ioctl SIOCGIFFLAGS");

1581

errno = ret_errno;

1582

1133

}

1583

1134

return false;

1584

1135

}

1585

1136

return true;

1586

1137

}

1587

1138

1588

__attribute__((nonnull, warn_unused_result))

1589

1139

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

1590

1140

1591

1141

/* Reject the loopback device */

1633

1183

* corresponds to an acceptable network device.

1634

1184

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

1635

1185

*/

1636

__attribute__((nonnull, warn_unused_result))

1637

1186

int good_interface(const struct dirent *if_entry){

1638

1187

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

1639

1188

return 0;

1655

1204

}

1656

1205

1657

1206

/*

1658

* This function determines if a network interface is up.

1659

*/

1660

__attribute__((nonnull, warn_unused_result))

1661

bool interface_is_up(const char *interface){

1662

struct ifreq ifr;

1663

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

1664

if(debug){

1665

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

1666

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

1667

}

1668

return false;

1669

}

1670

1671

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

1672

}

1673

1674

/*

1675

* This function determines if a network interface is running

1676

*/

1677

__attribute__((nonnull, warn_unused_result))

1678

bool interface_is_running(const char *interface){

1679

struct ifreq ifr;

1680

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

1681

if(debug){

1682

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

1683

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

1684

}

1685

return false;

1686

}

1687

1688

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

1689

}

1690

1691

__attribute__((nonnull, pure, warn_unused_result))

1207

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

1208

* corresponds to an acceptable network device which is up.

1209

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

1210

*/

1211

int up_interface(const struct dirent *if_entry){

1212

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

1213

return 0;

1214

}

1215

1216

struct ifreq ifr;

1217

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

1218

if(debug){

1219

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

1220

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

1221

}

1222

return 0;

1223

}

1224

1225

/* Reject down interfaces */

1226

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

1227

if(debug){

1228

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

1229

if_entry->d_name);

1230

}

1231

return 0;

1232

}

1233

1234

/* Reject non-running interfaces */

1235

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

1236

if(debug){

1237

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

1238

if_entry->d_name);

1239

}

1240

return 0;

1241

}

1242

1243

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

1244

return 0;

1245

}

1246

return 1;

1247

}

1248

1692

1249

int notdotentries(const struct dirent *direntry){

1693

1250

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

1694

1251

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

1701

1258

}

1702

1259

1703

1260

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

1704

__attribute__((nonnull, warn_unused_result))

1705

1261

int runnable_hook(const struct dirent *direntry){

1706

1262

int ret;

1707

1263

size_t sret;

1715

1271

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

1716

1272

"abcdefghijklmnopqrstuvwxyz"

1717

1273

"0123456789"

1718

"_.-");

1274

"_-");

1719

1275

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

1720

1276

/* Contains non-allowed characters */

1721

1277

if(debug){

1725

1281

return 0;

1726

1282

}

1727

1283

1728

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

1284

char *fullname = NULL;

1285

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

1286

if(ret < 0){

1287

perror_plus("asprintf");

1288

return 0;

1289

}

1290

1291

ret = stat(fullname, &st);

1729

1292

if(ret == -1){

1730

1293

if(debug){

1731

1294

perror_plus("Could not stat hook");

1755

1318

return 1;

1756

1319

}

1757

1320

1758

__attribute__((nonnull, warn_unused_result))

1759

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1760

mandos_context *mc){

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1761

1322

int ret;

1762

1323

struct timespec now;

1763

1324

struct timespec waited_time;

1764

1325

intmax_t block_time;

1765

1326

1766

1327

while(true){

1767

if(mc->current_server == NULL){

1768

if(debug){

1328

if(mc.current_server == NULL){

1329

if (debug){

1769

1330

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

1770

1331

" No timeout!\n");

1771

1332

}

1772

1333

ret = avahi_simple_poll_iterate(s, -1);

1773

1334

} else {

1774

if(debug){

1335

if (debug){

1775

1336

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

1776

1337

" it, or wait\n");

1777

1338

}

1784

1345

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

1785

1346

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

1786

1347

waited_time.tv_sec = (now.tv_sec

1787

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

1348

- mc.current_server->last_seen.tv_sec);

1788

1349

waited_time.tv_nsec = (now.tv_nsec

1789

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

1350

- mc.current_server->last_seen.tv_nsec);

1790

1351

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

1791

1352

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

1792

1353

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

1794

1355

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

1795

1356

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

1796

1357

1797

if(debug){

1358

if (debug){

1798

1359

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

1799

1360

block_time);

1800

1361

}

1801

1362

1802

1363

if(block_time <= 0){

1803

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

1804

mc->current_server->port,

1805

mc->current_server->if_index,

1806

mc->current_server->af, mc);

1364

ret = start_mandos_communication(mc.current_server->ip,

1365

mc.current_server->port,

1366

mc.current_server->if_index,

1367

mc.current_server->af);

1807

1368

if(ret == 0){

1808

avahi_simple_poll_quit(s);

1369

avahi_simple_poll_quit(mc.simple_poll);

1809

1370

return 0;

1810

1371

}

1811

1372

ret = clock_gettime(CLOCK_MONOTONIC,

1812

&mc->current_server->last_seen);

1373

&mc.current_server->last_seen);

1813

1374

if(ret == -1){

1814

1375

perror_plus("clock_gettime");

1815

1376

return -1;

1816

1377

}

1817

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

1378

mc.current_server = mc.current_server->next;

1818

1379

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

1819

1380

servers, but don't block */

1820

1381

}

1822

1383

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

1823

1384

}

1824

1385

if(ret != 0){

1825

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

1386

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

1826

1387

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

1827

1388

}

1828

1389

}

1829

1390

}

1830

1391

}

1831

1392

1832

__attribute__((nonnull))

1833

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

1393

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

1834

1394

const float delay){

1835

struct dirent **direntries = NULL;

1836

if(hookdir_fd == -1){

1837

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1838

| O_CLOEXEC);

1839

if(hookdir_fd == -1){

1840

if(errno == ENOENT){

1841

if(debug){

1842

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

1843

" found\n", hookdir);

1844

}

1845

} else {

1846

perror_plus("open");

1847

}

1848

return;

1849

}

1850

}

1851

#ifdef __GLIBC__

1852

#if __GLIBC_PREREQ(2, 15)

1853

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

1854

runnable_hook, alphasort);

1855

#else /* not __GLIBC_PREREQ(2, 15) */

1856

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

1857

alphasort);

1858

#endif /* not __GLIBC_PREREQ(2, 15) */

1859

#else /* not __GLIBC__ */

1860

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

1861

alphasort);

1862

#endif /* not __GLIBC__ */

1395

struct dirent **direntries;

1396

struct dirent *direntry;

1397

int ret;

1398

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

1399

alphasort);

1863

1400

if(numhooks == -1){

1864

1401

perror_plus("scandir");

1865

return;

1866

}

1867

struct dirent *direntry;

1868

int ret;

1869

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

1870

if(devnull == -1){

1871

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

1872

return;

1873

}

1874

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

1875

direntry = direntries[i];

1876

if(debug){

1877

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

1878

direntry->d_name);

1879

}

1880

pid_t hook_pid = fork();

1881

if(hook_pid == 0){

1882

/* Child */

1883

/* Raise privileges */

1884

errno = raise_privileges_permanently();

1885

if(errno != 0){

1886

perror_plus("Failed to raise privileges");

1887

_exit(EX_NOPERM);

1888

}

1889

/* Set group */

1890

errno = 0;

1891

ret = setgid(0);

1892

if(ret == -1){

1893

perror_plus("setgid");

1894

_exit(EX_NOPERM);

1895

}

1896

/* Reset supplementary groups */

1897

errno = 0;

1898

ret = setgroups(0, NULL);

1899

if(ret == -1){

1900

perror_plus("setgroups");

1901

_exit(EX_NOPERM);

1902

}

1903

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

1904

if(ret == -1){

1905

perror_plus("setenv");

1906

_exit(EX_OSERR);

1907

}

1908

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

1909

if(ret == -1){

1910

perror_plus("setenv");

1911

_exit(EX_OSERR);

1912

}

1913

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

1914

if(ret == -1){

1915

perror_plus("setenv");

1916

_exit(EX_OSERR);

1917

}

1918

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

1919

if(ret == -1){

1920

perror_plus("setenv");

1921

_exit(EX_OSERR);

1922

}

1923

char *delaystring;

1924

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

1925

if(ret == -1){

1402

} else {

1403

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

1404

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

1405

direntry = direntries[i];

1406

char *fullname = NULL;

1407

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

1408

if(ret < 0){

1926

1409

perror_plus("asprintf");

1927

_exit(EX_OSERR);

1928

}

1929

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

1930

if(ret == -1){

1410

continue;

1411

}

1412

if(debug){

1413

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

1414

direntry->d_name);

1415

}

1416

pid_t hook_pid = fork();

1417

if(hook_pid == 0){

1418

/* Child */

1419

/* Raise privileges */

1420

errno = 0;

1421

ret = seteuid(0);

1422

if(ret == -1){

1423

perror_plus("seteuid");

1424

}

1425

/* Raise privileges even more */

1426

errno = 0;

1427

ret = setuid(0);

1428

if(ret == -1){

1429

perror_plus("setuid");

1430

}

1431

/* Set group */

1432

errno = 0;

1433

ret = setgid(0);

1434

if(ret == -1){

1435

perror_plus("setgid");

1436

}

1437

/* Reset supplementary groups */

1438

errno = 0;

1439

ret = setgroups(0, NULL);

1440

if(ret == -1){

1441

perror_plus("setgroups");

1442

}

1443

dup2(devnull, STDIN_FILENO);

1444

close(devnull);

1445

dup2(STDERR_FILENO, STDOUT_FILENO);

1446

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

1447

if(ret == -1){

1448

perror_plus("setenv");

1449

_exit(EX_OSERR);

1450

}

1451

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

1452

if(ret == -1){

1453

perror_plus("setenv");

1454

_exit(EX_OSERR);

1455

}

1456

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

1457

if(ret == -1){

1458

perror_plus("setenv");

1459

_exit(EX_OSERR);

1460

}

1461

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

1462

if(ret == -1){

1463

perror_plus("setenv");

1464

_exit(EX_OSERR);

1465

}

1466

char *delaystring;

1467

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

1468

if(ret == -1){

1469

perror_plus("asprintf");

1470

_exit(EX_OSERR);

1471

}

1472

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

1473

if(ret == -1){

1474

free(delaystring);

1475

perror_plus("setenv");

1476

_exit(EX_OSERR);

1477

}

1931

1478

free(delaystring);

1932

perror_plus("setenv");

1933

_exit(EX_OSERR);

1934

}

1935

free(delaystring);

1936

if(connect_to != NULL){

1937

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

1938

if(ret == -1){

1939

perror_plus("setenv");

1940

_exit(EX_OSERR);

1941

}

1942

}

1943

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

1944

direntry->d_name,

1945

O_RDONLY));

1946

if(hook_fd == -1){

1947

perror_plus("openat");

1948

_exit(EXIT_FAILURE);

1949

}

1950

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

1951

perror_plus("close");

1952

_exit(EXIT_FAILURE);

1953

}

1954

ret = dup2(devnull, STDIN_FILENO);

1955

if(ret == -1){

1956

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

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("close");

1962

_exit(EX_OSERR);

1963

}

1964

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1965

if(ret == -1){

1966

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

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

environ) == -1){

1971

perror_plus("fexecve");

1972

_exit(EXIT_FAILURE);

1973

}

1974

} else {

1975

if(hook_pid == -1){

1976

perror_plus("fork");

1977

free(direntry);

1978

continue;

1979

}

1980

int status;

1981

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

1982

perror_plus("waitpid");

1983

free(direntry);

1984

continue;

1985

}

1986

if(WIFEXITED(status)){

1987

if(WEXITSTATUS(status) != 0){

1988

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

1989

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

1990

WEXITSTATUS(status));

1991

free(direntry);

1992

continue;

1993

}

1994

} else if(WIFSIGNALED(status)){

1995

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

1996

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

1997

WTERMSIG(status));

1998

free(direntry);

1999

continue;

2000

} else {

2001

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

2002

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

2003

free(direntry);

2004

continue;

2005

}

2006

}

2007

if(debug){

2008

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

2009

direntry->d_name);

2010

}

2011

free(direntry);

2012

}

2013

free(direntries);

2014

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

2015

perror_plus("close");

2016

} else {

2017

hookdir_fd = -1;

2018

}

2019

close(devnull);

2020

}

2021

2022

__attribute__((nonnull, warn_unused_result))

2023

error_t bring_up_interface(const char *const interface,

2024

const float delay){

2025

error_t old_errno = errno;

2026

int ret;

2027

struct ifreq network;

2028

unsigned int if_index = if_nametoindex(interface);

2029

if(if_index == 0){

2030

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

2031

errno = old_errno;

2032

return ENXIO;

2033

}

2034

2035

if(quit_now){

2036

errno = old_errno;

2037

return EINTR;

2038

}

2039

2040

if(not interface_is_up(interface)){

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

2043

ret_errno = errno;

2044

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

2045

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

2046

errno = old_errno;

2047

return ret_errno;

2048

}

2049

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

2050

2051

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

2052

if(sd == -1){

2053

ret_errno = errno;

2054

perror_plus("socket");

2055

errno = old_errno;

2056

return ret_errno;

2057

}

2058

2059

if(quit_now){

2060

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

2061

if(ret == -1){

2062

perror_plus("close");

2063

}

2064

errno = old_errno;

2065

return EINTR;

2066

}

2067

2068

if(debug){

2069

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

2070

interface);

2071

}

2072

2073

/* Raise privileges */

2074

ret_errno = raise_privileges();

2075

if(ret_errno != 0){

2076

errno = ret_errno;

2077

perror_plus("Failed to raise privileges");

2078

}

2079

2080

#ifdef __linux__

2081

int ret_linux;

2082

bool restore_loglevel = false;

2083

if(ret_errno == 0){

2084

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2085

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

2086

ret_linux = klogctl(8, NULL, 5);

2087

if(ret_linux == -1){

2088

perror_plus("klogctl");

2089

} else {

2090

restore_loglevel = true;

2091

}

2092

}

2093

#endif /* __linux__ */

2094

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

2095

ioctl_errno = errno;

2096

#ifdef __linux__

2097

if(restore_loglevel){

2098

ret_linux = klogctl(7, NULL, 0);

2099

if(ret_linux == -1){

2100

perror_plus("klogctl");

2101

}

2102

}

2103

#endif /* __linux__ */

2104

2105

/* If raise_privileges() succeeded above */

2106

if(ret_errno == 0){

2107

/* Lower privileges */

2108

ret_errno = lower_privileges();

2109

if(ret_errno != 0){

2110

errno = ret_errno;

2111

perror_plus("Failed to lower privileges");

2112

}

2113

}

2114

2115

/* Close the socket */

2116

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

2117

if(ret == -1){

2118

perror_plus("close");

2119

}

2120

2121

if(ret_setflags == -1){

2122

errno = ioctl_errno;

2123

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2124

errno = old_errno;

2125

return ioctl_errno;

2126

}

2127

} else if(debug){

2128

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

2129

interface);

2130

}

2131

2132

/* Sleep checking until interface is running.

2133

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

2134

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

2135

if(interface_is_running(interface)){

2136

break;

2137

}

2138

struct timespec sleeptime = { .tv_nsec = 250000000 };

2139

ret = nanosleep(&sleeptime, NULL);

2140

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

2141

perror_plus("nanosleep");

2142

}

2143

}

2144

2145

errno = old_errno;

2146

return 0;

2147

}

2148

2149

__attribute__((nonnull, warn_unused_result))

2150

error_t take_down_interface(const char *const interface){

2151

error_t old_errno = errno;

2152

struct ifreq network;

2153

unsigned int if_index = if_nametoindex(interface);

2154

if(if_index == 0){

2155

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

2156

errno = old_errno;

2157

return ENXIO;

2158

}

2159

if(interface_is_up(interface)){

2160

error_t ret_errno = 0, ioctl_errno = 0;

2161

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

2162

ret_errno = errno;

2163

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

2164

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

2165

errno = old_errno;

2166

return ret_errno;

2167

}

2168

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

2169

2170

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

2171

if(sd == -1){

2172

ret_errno = errno;

2173

perror_plus("socket");

2174

errno = old_errno;

2175

return ret_errno;

2176

}

2177

2178

if(debug){

2179

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

2180

interface);

2181

}

2182

2183

/* Raise privileges */

2184

ret_errno = raise_privileges();

2185

if(ret_errno != 0){

2186

errno = ret_errno;

2187

perror_plus("Failed to raise privileges");

2188

}

2189

2190

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

2191

ioctl_errno = errno;

2192

2193

/* If raise_privileges() succeeded above */

2194

if(ret_errno == 0){

2195

/* Lower privileges */

2196

ret_errno = lower_privileges();

2197

if(ret_errno != 0){

2198

errno = ret_errno;

2199

perror_plus("Failed to lower privileges");

2200

}

2201

}

2202

2203

/* Close the socket */

2204

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

2205

if(ret == -1){

2206

perror_plus("close");

2207

}

2208

2209

if(ret_setflags == -1){

2210

errno = ioctl_errno;

2211

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2212

errno = old_errno;

2213

return ioctl_errno;

2214

}

2215

} else if(debug){

2216

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

2217

interface);

2218

}

2219

2220

errno = old_errno;

2221

return 0;

1479

if(connect_to != NULL){

1480

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

1481

if(ret == -1){

1482

perror_plus("setenv");

1483

_exit(EX_OSERR);

1484

}

1485

}

1486

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

1487

perror_plus("execl");

1488

_exit(EXIT_FAILURE);

1489

}

1490

} else {

1491

int status;

1492

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

1493

perror_plus("waitpid");

1494

free(fullname);

1495

continue;

1496

}

1497

if(WIFEXITED(status)){

1498

if(WEXITSTATUS(status) != 0){

1499

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

1500

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

1501

WEXITSTATUS(status));

1502

free(fullname);

1503

continue;

1504

}

1505

} else if(WIFSIGNALED(status)){

1506

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

1507

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

1508

WTERMSIG(status));

1509

free(fullname);

1510

continue;

1511

} else {

1512

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

1513

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

1514

free(fullname);

1515

continue;

1516

}

1517

}

1518

free(fullname);

1519

if(debug){

1520

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

1521

direntry->d_name);

1522

}

1523

}

1524

close(devnull);

1525

}

1526

return true;

2222

1527

}

2223

1528

2224

1529

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

2225

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

2226

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

2227

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

2228

.interfaces = NULL, .interfaces_size = 0 };

2229

1530

AvahiSServiceBrowser *sb = NULL;

2230

error_t ret_errno;

1531

int error;

2231

1532

int ret;

2232

1533

intmax_t tmpmax;

2233

1534

char *tmp;

2234

1535

int exitcode = EXIT_SUCCESS;

2235

char *interfaces_to_take_down = NULL;

2236

size_t interfaces_to_take_down_size = 0;

2237

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

2238

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

2239

char *tempdir = NULL;

1536

const char *interface = "";

1537

struct ifreq network;

1538

int sd = -1;

1539

bool take_down_interface = false;

1540

uid_t uid;

1541

gid_t gid;

1542

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

1543

bool tempdir_created = false;

2240

1544

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2241

1545

const char *seckey = PATHDIR "/" SECKEY;

2242

1546

const char *pubkey = PATHDIR "/" PUBKEY;

2243

char *interfaces_hooks = NULL;

2244

1547

2245

1548

bool gnutls_initialized = false;

2246

1549

bool gpgme_initialized = false;

2337

1640

connect_to = arg;

2338

1641

break;

2339

1642

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

2340

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

2341

arg, (int)',');

2342

if(ret_errno != 0){

2343

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

2344

}

1643

interface = arg;

2345

1644

break;

2346

1645

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

2347

1646

seckey = arg;

2419

1718

goto end;

2420

1719

}

2421

1720

}

2422

1721

2423

1722

{

2424

1723

/* Work around Debian bug #633582:

2425

1724

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

2426

1725

2427

/* Re-raise privileges */

2428

ret_errno = raise_privileges();

2429

if(ret_errno != 0){

2430

errno = ret_errno;

2431

perror_plus("Failed to raise privileges");

1726

/* Re-raise priviliges */

1727

errno = 0;

1728

ret = seteuid(0);

1729

if(ret == -1){

1730

perror_plus("seteuid");

2432

1731

} else {

2433

1732

struct stat st;

2434

1733

2452

1751

TEMP_FAILURE_RETRY(close(seckey_fd));

2453

1752

}

2454

1753

}

2455

1754

2456

1755

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

2457

1756

int pubkey_fd = open(pubkey, O_RDONLY);

2458

1757

if(pubkey_fd == -1){

2473

1772

TEMP_FAILURE_RETRY(close(pubkey_fd));

2474

1773

}

2475

1774

}

2476

1775

2477

1776

/* Lower privileges */

2478

ret_errno = lower_privileges();

2479

if(ret_errno != 0){

2480

errno = ret_errno;

2481

perror_plus("Failed to lower privileges");

2482

}

2483

}

2484

}

2485

2486

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

2487

{

2488

char *interface = NULL;

2489

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

2490

interface))){

2491

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

2492

and if_nametoindex(interface) == 0){

2493

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

2494

fprintf_plus(stderr, "Not using nonexisting interface"

2495

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

2496

}

2497

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

2498

interface = NULL;

1777

errno = 0;

1778

ret = seteuid(uid);

1779

if(ret == -1){

1780

perror_plus("seteuid");

2499

1781

}

2500

1782

}

2501

1783

}

2502

1784

2503

1785

/* Run network hooks */

2504

{

2505

if(mc.interfaces != NULL){

2506

interfaces_hooks = malloc(mc.interfaces_size);

2507

if(interfaces_hooks == NULL){

2508

perror_plus("malloc");

2509

goto end;

2510

}

2511

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

2512

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

2513

}

2514

run_network_hooks("start", interfaces_hooks != NULL ?

2515

interfaces_hooks : "", delay);

1786

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

1787

goto end;

2516

1788

}

2517

1789

2518

1790

if(not debug){

2519

1791

avahi_set_log_function(empty_log);

2520

1792

}

2521

1793

1794

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

1795

struct dirent **direntries;

1796

/* First look for interfaces that are up */

1797

ret = scandir(sys_class_net, &direntries, up_interface,

1798

alphasort);

1799

if(ret == 0){

1800

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

1801

free(direntries);

1802

ret = scandir(sys_class_net, &direntries, good_interface,

1803

alphasort);

1804

}

1805

if(ret >= 1){

1806

/* Pick the first interface returned */

1807

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

1808

if(debug){

1809

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

1810

}

1811

if(interface == NULL){

1812

perror_plus("malloc");

1813

free(direntries);

1814

exitcode = EXIT_FAILURE;

1815

goto end;

1816

}

1817

free(direntries);

1818

} else {

1819

free(direntries);

1820

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

1821

exitcode = EXIT_FAILURE;

1822

goto end;

1823

}

1824

}

1825

2522

1826

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

2523

1827

from the signal handler */

2524

1828

/* Initialize the pseudo-RNG for Avahi */

2525

1829

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

2526

simple_poll = avahi_simple_poll_new();

2527

if(simple_poll == NULL){

1830

mc.simple_poll = avahi_simple_poll_new();

1831

if(mc.simple_poll == NULL){

2528

1832

fprintf_plus(stderr,

2529

1833

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

2530

1834

exitcode = EX_UNAVAILABLE;

2594

1898

}

2595

1899

}

2596

1900

2597

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

2598

if(mc.interfaces == NULL){

2599

struct dirent **direntries = NULL;

2600

/* Look for any good interfaces */

2601

ret = scandir(sys_class_net, &direntries, good_interface,

2602

alphasort);

2603

if(ret >= 1){

2604

/* Add all found interfaces to interfaces list */

2605

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

2606

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

2607

direntries[i]->d_name);

2608

if(ret_errno != 0){

2609

errno = ret_errno;

2610

perror_plus("argz_add");

2611

free(direntries[i]);

2612

continue;

2613

}

2614

if(debug){

2615

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

2616

direntries[i]->d_name);

2617

}

2618

free(direntries[i]);

2619

}

2620

free(direntries);

2621

} else {

2622

if(ret == 0){

2623

free(direntries);

2624

}

2625

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

2626

exitcode = EXIT_FAILURE;

2627

goto end;

2628

}

2629

}

2630

2631

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

2632

{

2633

char *interface = NULL;

2634

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

2635

interface))){

2636

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

2637

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

2638

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

2639

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

2640

interface);

2641

interface = NULL;

2642

while((interface = argz_next(mc.interfaces,

2643

mc.interfaces_size, interface))){

2644

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

2645

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

2646

interface);

2647

interface = NULL;

1901

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

1902

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

1903

if_index = (AvahiIfIndex) if_nametoindex(interface);

1904

if(if_index == 0){

1905

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

1906

exitcode = EX_UNAVAILABLE;

1907

goto end;

1908

}

1909

1910

if(quit_now){

1911

goto end;

1912

}

1913

1914

/* Re-raise priviliges */

1915

errno = 0;

1916

ret = seteuid(0);

1917

if(ret == -1){

1918

perror_plus("seteuid");

1919

}

1920

1921

#ifdef __linux__

1922

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1923

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

1924

ret = klogctl(8, NULL, 5);

1925

bool restore_loglevel = true;

1926

if(ret == -1){

1927

restore_loglevel = false;

1928

perror_plus("klogctl");

1929

}

1930

#endif /* __linux__ */

1931

1932

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1933

if(sd < 0){

1934

perror_plus("socket");

1935

exitcode = EX_OSERR;

1936

#ifdef __linux__

1937

if(restore_loglevel){

1938

ret = klogctl(7, NULL, 0);

1939

if(ret == -1){

1940

perror_plus("klogctl");

1941

}

1942

}

1943

#endif /* __linux__ */

1944

/* Lower privileges */

1945

errno = 0;

1946

ret = seteuid(uid);

1947

if(ret == -1){

1948

perror_plus("seteuid");

1949

}

1950

goto end;

1951

}

1952

strcpy(network.ifr_name, interface);

1953

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

1954

if(ret == -1){

1955

perror_plus("ioctl SIOCGIFFLAGS");

1956

#ifdef __linux__

1957

if(restore_loglevel){

1958

ret = klogctl(7, NULL, 0);

1959

if(ret == -1){

1960

perror_plus("klogctl");

1961

}

1962

}

1963

#endif /* __linux__ */

1964

exitcode = EX_OSERR;

1965

/* Lower privileges */

1966

errno = 0;

1967

ret = seteuid(uid);

1968

if(ret == -1){

1969

perror_plus("seteuid");

1970

}

1971

goto end;

1972

}

1973

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

1974

network.ifr_flags |= IFF_UP;

1975

take_down_interface = true;

1976

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

1977

if(ret == -1){

1978

take_down_interface = false;

1979

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1980

exitcode = EX_OSERR;

1981

#ifdef __linux__

1982

if(restore_loglevel){

1983

ret = klogctl(7, NULL, 0);

1984

if(ret == -1){

1985

perror_plus("klogctl");

2648

1986

}

2649

1987

}

1988

#endif /* __linux__ */

1989

/* Lower privileges */

1990

errno = 0;

1991

ret = seteuid(uid);

1992

if(ret == -1){

1993

perror_plus("seteuid");

1994

}

1995

goto end;

1996

}

1997

}

1998

/* Sleep checking until interface is running.

1999

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

2000

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

2001

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

2002

if(ret == -1){

2003

perror_plus("ioctl SIOCGIFFLAGS");

2004

} else if(network.ifr_flags & IFF_RUNNING){

2650

2005

break;

2651

2006

}

2652

bool interface_was_up = interface_is_up(interface);

2653

errno = bring_up_interface(interface, delay);

2654

if(not interface_was_up){

2655

if(errno != 0){

2656

perror_plus("Failed to bring up interface");

2657

} else {

2658

errno = argz_add(&interfaces_to_take_down,

2659

&interfaces_to_take_down_size,

2660

interface);

2661

if(errno != 0){

2662

perror_plus("argz_add");

2663

}

2664

}

2665

}

2666

}

2667

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

2668

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

2669

}

2670

}

2671

2672

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

2673

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

2674

if(debug){

2675

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

2676

mc.interfaces);

2677

}

2678

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

2007

struct timespec sleeptime = { .tv_nsec = 250000000 };

2008

ret = nanosleep(&sleeptime, NULL);

2009

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

2010

perror_plus("nanosleep");

2011

}

2012

}

2013

if(not take_down_interface){

2014

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

2015

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

2016

if(ret == -1){

2017

perror_plus("close");

2018

}

2019

}

2020

#ifdef __linux__

2021

if(restore_loglevel){

2022

/* Restores kernel loglevel to default */

2023

ret = klogctl(7, NULL, 0);

2024

if(ret == -1){

2025

perror_plus("klogctl");

2026

}

2027

}

2028

#endif /* __linux__ */

2029

/* Lower privileges */

2030

errno = 0;

2031

/* Lower privileges */

2032

ret = seteuid(uid);

2033

if(ret == -1){

2034

perror_plus("seteuid");

2035

}

2679

2036

}

2680

2037

2681

2038

if(quit_now){

2682

2039

goto end;

2683

2040

}

2684

2041

2685

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

2042

ret = init_gnutls_global(pubkey, seckey);

2686

2043

if(ret == -1){

2687

2044

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

2688

2045

exitcode = EX_UNAVAILABLE;

2695

2052

goto end;

2696

2053

}

2697

2054

2698

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

2699

tempdir = mkdtemp(run_tempdir);

2700

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

2701

if(debug){

2702

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

2703

run_tempdir, old_tempdir);

2704

}

2705

tempdir = mkdtemp(old_tempdir);

2706

}

2707

if(tempdir == NULL){

2055

if(mkdtemp(tempdir) == NULL){

2708

2056

perror_plus("mkdtemp");

2709

2057

goto end;

2710

2058

}

2059

tempdir_created = true;

2711

2060

2712

2061

if(quit_now){

2713

2062

goto end;

2714

2063

}

2715

2064

2716

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

2065

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

2717

2066

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

2718

2067

exitcode = EX_UNAVAILABLE;

2719

2068

goto end;

2729

2078

/* Connect directly, do not use Zeroconf */

2730

2079

/* (Mainly meant for debugging) */

2731

2080

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

2732

2733

2081

if(address == NULL){

2734

2082

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

2735

2083

exitcode = EX_USAGE;

2740

2088

goto end;

2741

2089

}

2742

2090

2743

in_port_t port;

2091

uint16_t port;

2744

2092

errno = 0;

2745

2093

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

2746

2094

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

2747

or tmpmax != (in_port_t)tmpmax){

2095

or tmpmax != (uint16_t)tmpmax){

2748

2096

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

2749

2097

exitcode = EX_USAGE;

2750

2098

goto end;

2751

2099

}

2752

2100

2753

2101

if(quit_now){

2754

2102

goto end;

2755

2103

}

2756

2104

2757

port = (in_port_t)tmpmax;

2105

port = (uint16_t)tmpmax;

2758

2106

*address = '\0';

2759

2107

/* Colon in address indicates IPv6 */

2760

2108

int af;

2776

2124

}

2777

2125

2778

2126

while(not quit_now){

2779

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

2780

&mc);

2127

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

2781

2128

if(quit_now or ret == 0){

2782

2129

break;

2783

2130

}

2785

2132

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

2786

2133

(int)retry_interval);

2787

2134

}

2788

sleep((unsigned int)retry_interval);

2135

sleep((int)retry_interval);

2789

2136

}

2790

2137

2791

if(not quit_now){

2138

if (not quit_now){

2792

2139

exitcode = EXIT_SUCCESS;

2793

2140

}

2794

2141

2809

2156

config.publish_domain = 0;

2810

2157

2811

2158

/* Allocate a new server */

2812

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2813

&config, NULL, NULL, &ret_errno);

2159

mc.server = avahi_server_new(avahi_simple_poll_get

2160

(mc.simple_poll), &config, NULL,

2161

NULL, &error);

2814

2162

2815

2163

/* Free the Avahi configuration data */

2816

2164

avahi_server_config_free(&config);

2819

2167

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

2820

2168

if(mc.server == NULL){

2821

2169

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

2822

avahi_strerror(ret_errno));

2170

avahi_strerror(error));

2823

2171

exitcode = EX_UNAVAILABLE;

2824

2172

goto end;

2825

2173

}

2831

2179

/* Create the Avahi service browser */

2832

2180

sb = avahi_s_service_browser_new(mc.server, if_index,

2833

2181

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2834

NULL, 0, browse_callback,

2835

(void *)&mc);

2182

NULL, 0, browse_callback, NULL);

2836

2183

if(sb == NULL){

2837

2184

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

2838

2185

avahi_strerror(avahi_server_errno(mc.server)));

2849

2196

if(debug){

2850

2197

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

2851

2198

}

2852

2853

ret = avahi_loop_with_timeout(simple_poll,

2854

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

2199

2200

ret = avahi_loop_with_timeout(mc.simple_poll,

2201

(int)(retry_interval * 1000));

2855

2202

if(debug){

2856

2203

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

2857

2204

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

2864

2211

}

2865

2212

2866

2213

/* Cleanup things */

2867

free(mc.interfaces);

2868

2869

2214

if(sb != NULL)

2870

2215

avahi_s_service_browser_free(sb);

2871

2216

2872

2217

if(mc.server != NULL)

2873

2218

avahi_server_free(mc.server);

2874

2219

2875

if(simple_poll != NULL)

2876

avahi_simple_poll_free(simple_poll);

2220

if(mc.simple_poll != NULL)

2221

avahi_simple_poll_free(mc.simple_poll);

2877

2222

2878

2223

if(gnutls_initialized){

2879

2224

gnutls_certificate_free_credentials(mc.cred);

2891

2236

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

2892

2237

while(mc.current_server != NULL){

2893

2238

server *next = mc.current_server->next;

2894

#ifdef __GNUC__

2895

#pragma GCC diagnostic push

2896

#pragma GCC diagnostic ignored "-Wcast-qual"

2897

#endif

2898

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

2899

#ifdef __GNUC__

2900

#pragma GCC diagnostic pop

2901

#endif

2902

2239

free(mc.current_server);

2903

2240

mc.current_server = next;

2904

2241

}

2905

2242

}

2906

2243

2907

/* Re-raise privileges */

2244

/* Run network hooks */

2245

run_network_hooks("stop", interface, delay);

2246

2247

/* Re-raise priviliges */

2908

2248

{

2909

ret_errno = raise_privileges();

2910

if(ret_errno != 0){

2911

errno = ret_errno;

2912

perror_plus("Failed to raise privileges");

2913

} else {

2914

2915

/* Run network hooks */

2916

run_network_hooks("stop", interfaces_hooks != NULL ?

2917

interfaces_hooks : "", delay);

2918

2919

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

2920

{

2921

char *interface = NULL;

2922

while((interface=argz_next(interfaces_to_take_down,

2923

interfaces_to_take_down_size,

2924

interface))){

2925

ret_errno = take_down_interface(interface);

2926

if(ret_errno != 0){

2927

errno = ret_errno;

2928

perror_plus("Failed to take down interface");

2929

}

2930

}

2931

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

2932

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

2933

" down\n");

2934

}

2935

}

2249

errno = 0;

2250

ret = seteuid(0);

2251

if(ret == -1){

2252

perror_plus("seteuid");

2936

2253

}

2937

2254

2938

ret_errno = lower_privileges_permanently();

2939

if(ret_errno != 0){

2940

errno = ret_errno;

2941

perror_plus("Failed to lower privileges permanently");

2255

/* Take down the network interface */

2256

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

2257

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

2258

if(ret == -1){

2259

perror_plus("ioctl SIOCGIFFLAGS");

2260

} else if(network.ifr_flags & IFF_UP){

2261

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

2262

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

2263

if(ret == -1){

2264

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2265

}

2266

}

2267

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

2268

if(ret == -1){

2269

perror_plus("close");

2270

}

2942

2271

}

2943

2272

}

2944

2945

free(interfaces_to_take_down);

2946

free(interfaces_hooks);

2273

/* Lower privileges permanently */

2274

errno = 0;

2275

ret = setuid(uid);

2276

if(ret == -1){

2277

perror_plus("setuid");

2278

}

2947

2279

2948

2280

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

2949

if(tempdir != NULL){

2281

if(tempdir_created){

2950

2282

struct dirent **direntries = NULL;

2951

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY

2952

| O_NOFOLLOW

2953

| O_DIRECTORY

2954

| O_PATH));

2955

if(tempdir_fd == -1){

2956

perror_plus("open");

2957

} else {

2958

#ifdef __GLIBC__

2959

#if __GLIBC_PREREQ(2, 15)

2960

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

2961

notdotentries, alphasort);

2962

#else /* not __GLIBC_PREREQ(2, 15) */

2963

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

2964

alphasort);

2965

#endif /* not __GLIBC_PREREQ(2, 15) */

2966

#else /* not __GLIBC__ */

2967

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

2968

alphasort);

2969

#endif /* not __GLIBC__ */

2970

if(numentries >= 0){

2971

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

2972

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

2973

if(ret == -1){

2974

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

2975

" \"%s\", 0): %s\n", tempdir,

2976

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

2977

}

2978

free(direntries[i]);

2979

}

2980

2981

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

2982

free(direntries);

2983

if(numentries == -1){

2984

perror_plus("scandir");

2985

}

2986

ret = rmdir(tempdir);

2987

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

2988

perror_plus("rmdir");

2989

}

2283

struct dirent *direntry = NULL;

2284

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

2285

alphasort);

2286

if (numentries > 0){

2287

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

2288

direntry = direntries[i];

2289

char *fullname = NULL;

2290

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

2291

direntry->d_name);

2292

if(ret < 0){

2293

perror_plus("asprintf");

2294

continue;

2295

}

2296

ret = remove(fullname);

2297

if(ret == -1){

2298

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

2299

strerror(errno));

2300

}

2301

free(fullname);

2990

2302

}

2991

TEMP_FAILURE_RETRY(close(tempdir_fd));

2303

}

2304

2305

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

2306

free(direntries);

2307

if (numentries == -1){

2308

perror_plus("scandir");

2309

}

2310

ret = rmdir(tempdir);

2311

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

2312

perror_plus("rmdir");

2992

2313

}

2993

2314

}

2994

2315