/mandos/trunk : revision 753

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

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

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

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42

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

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stdout, ferror(), remove() */

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stdout, ferror() */

44

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

45

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

46

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

55

opendir(), DIR */

56

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

57

#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() */

60

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

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61

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

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62

*/

62

63

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

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73

*/

73

74

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

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

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

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

76

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

77

unlinkat() */

78

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

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79

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

78

80

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

79

81

argp_state, struct argp,

91

93

argz_delete(), argz_append(),

92

94

argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

141

146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

161

166

const char *priority;

162

167

gpgme_ctx_t ctx;

163

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

164

171

} mandos_context;

165

172

166

173

/* global so signal handler can reach it*/

167

174

AvahiSimplePoll *simple_poll;

168

mandos_context mc = { .server = NULL, .dh_bits = 1024,

169

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

170

"+CTYPE-OPENPGP", .current_server = NULL };

171

175

172

176

sig_atomic_t quit_now = 0;

173

177

int signal_received = 0;

181

185

perror(print_text);

182

186

}

183

187

184

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

188

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

185

189

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

186

190

va_list ap;

187

191

va_start (ap, format);

188

192

189

193

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

190

194

program_invocation_short_name));

191

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

195

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

192

196

}

193

197

194

198

/*

196

200

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

197

201

* "buffer_length" is how much is already used.

198

202

*/

203

__attribute__((nonnull, warn_unused_result))

199

204

size_t incbuffer(char **buffer, size_t buffer_length,

200

205

size_t buffer_capacity){

201

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

202

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

203

if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

204

213

return 0;

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214

}

215

*buffer = new_buf;

206

216

buffer_capacity += BUFFER_SIZE;

207

217

}

208

218

return buffer_capacity;

209

219

}

210

220

211

221

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

222

__attribute__((nonnull, warn_unused_result))

212

223

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

213

int af){

224

int af, server **current_server){

214

225

int ret;

215

226

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

216

227

if(new_server == NULL){

223

234

.af = af };

224

235

if(new_server->ip == NULL){

225

236

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);

226

252

return false;

227

253

}

228

254

/* Special case of first server */

229

if (mc.current_server == NULL){

255

if(*current_server == NULL){

230

256

new_server->next = new_server;

231

257

new_server->prev = new_server;

232

mc.current_server = new_server;

233

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

258

*current_server = new_server;

234

259

} else {

235

new_server->next = mc.current_server;

236

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

260

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

261

new_server->next = *current_server;

262

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

237

263

new_server->prev->next = new_server;

238

mc.current_server->prev = new_server;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

return false;

264

(*current_server)->prev = new_server;

244

265

}

245

266

return true;

246

267

}

248

269

/*

249

270

* Initialize GPGME.

250

271

*/

251

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

252

const char *tempdir){

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){

253

277

gpgme_error_t rc;

254

278

gpgme_engine_info_t engine_info;

255

279

256

280

/*

257

281

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

258

282

*/

259

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

260

284

int ret;

261

285

int fd;

262

286

gpgme_data_t pgp_data;

274

298

return false;

275

299

}

276

300

277

rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

278

302

if(rc != GPG_ERR_NO_ERROR){

279

303

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

280

304

gpgme_strsource(rc), gpgme_strerror(rc));

324

348

}

325

349

326

350

/* Create new GPGME "context" */

327

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

351

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

328

352

if(rc != GPG_ERR_NO_ERROR){

329

353

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

330

354

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

343

367

* Decrypt OpenPGP data.

344

368

* Returns -1 on error

345

369

*/

370

__attribute__((nonnull, warn_unused_result))

346

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

347

372

size_t crypto_size,

348

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

349

375

gpgme_data_t dh_crypto, dh_plain;

350

376

gpgme_error_t rc;

351

377

ssize_t ret;

377

403

378

404

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

379

405

data buffer */

380

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

406

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

381

407

if(rc != GPG_ERR_NO_ERROR){

382

408

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

383

409

gpgme_strsource(rc), gpgme_strerror(rc));

384

410

plaintext_length = -1;

385

411

if(debug){

386

412

gpgme_decrypt_result_t result;

387

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

388

414

if(result == NULL){

389

415

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

390

416

} else {

467

493

return plaintext_length;

468

494

}

469

495

470

static const char * safer_gnutls_strerror(int value){

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){

471

505

const char *ret = gnutls_strerror(value);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

506

return safe_string(ret);

475

507

}

476

508

477

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

478

511

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

479

512

const char* string){

480

513

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

481

514

}

482

515

516

__attribute__((nonnull, warn_unused_result))

483

517

static int init_gnutls_global(const char *pubkeyfilename,

484

const char *seckeyfilename){

518

const char *seckeyfilename,

519

mandos_context *mc){

485

520

int ret;

521

unsigned int uret;

486

522

487

523

if(debug){

488

524

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

504

540

}

505

541

506

542

/* OpenPGP credentials */

507

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

508

544

if(ret != GNUTLS_E_SUCCESS){

509

545

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

510

546

safer_gnutls_strerror(ret));

520

556

}

521

557

522

558

ret = gnutls_certificate_set_openpgp_key_file

523

(mc.cred, pubkeyfilename, seckeyfilename,

559

(mc->cred, pubkeyfilename, seckeyfilename,

524

560

GNUTLS_OPENPGP_FMT_BASE64);

525

561

if(ret != GNUTLS_E_SUCCESS){

526

562

fprintf_plus(stderr,

532

568

}

533

569

534

570

/* GnuTLS server initialization */

535

ret = gnutls_dh_params_init(&mc.dh_params);

571

ret = gnutls_dh_params_init(&mc->dh_params);

536

572

if(ret != GNUTLS_E_SUCCESS){

537

573

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

538

574

" initialization: %s\n",

539

575

safer_gnutls_strerror(ret));

540

576

goto globalfail;

541

577

}

542

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

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);

543

680

if(ret != GNUTLS_E_SUCCESS){

544

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

545

safer_gnutls_strerror(ret));

681

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

682

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

546

683

goto globalfail;

547

684

}

548

685

549

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

686

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

550

687

551

688

return 0;

552

689

553

690

globalfail:

554

691

555

gnutls_certificate_free_credentials(mc.cred);

692

gnutls_certificate_free_credentials(mc->cred);

556

693

gnutls_global_deinit();

557

gnutls_dh_params_deinit(mc.dh_params);

694

gnutls_dh_params_deinit(mc->dh_params);

558

695

return -1;

559

696

}

560

697

561

static int init_gnutls_session(gnutls_session_t *session){

698

__attribute__((nonnull, warn_unused_result))

699

static int init_gnutls_session(gnutls_session_t *session,

700

mandos_context *mc){

562

701

int ret;

563

702

/* GnuTLS session creation */

564

703

do {

576

715

{

577

716

const char *err;

578

717

do {

579

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

718

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

580

719

if(quit_now){

581

720

gnutls_deinit(*session);

582

721

return -1;

593

732

594

733

do {

595

734

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

596

mc.cred);

735

mc->cred);

597

736

if(quit_now){

598

737

gnutls_deinit(*session);

599

738

return -1;

609

748

/* ignore client certificate if any. */

610

749

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

611

750

612

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

751

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

613

752

614

753

return 0;

615

754

}

619

758

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

620

759

621

760

/* Called when a Mandos server is found */

761

__attribute__((nonnull, warn_unused_result))

622

762

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

623

763

AvahiIfIndex if_index,

624

int af){

764

int af, mandos_context *mc){

625

765

int ret, tcp_sd = -1;

626

766

ssize_t sret;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

767

struct sockaddr_storage to;

631

768

char *buffer = NULL;

632

769

char *decrypted_buffer = NULL;

633

770

size_t buffer_length = 0;

657

794

return -1;

658

795

}

659

796

660

ret = init_gnutls_session(&session);

797

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

798

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

799

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

800

bool match = false;

801

{

802

char *interface = NULL;

803

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

804

interface))){

805

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

806

match = true;

807

break;

808

}

809

}

810

}

811

if(not match){

812

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

813

connect to the server */

814

if(debug){

815

char interface[IF_NAMESIZE];

816

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

817

perror_plus("if_indextoname");

818

} else {

819

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

820

" \"%s\"\n",

821

if_indextoname((unsigned int)if_index,

822

interface));

823

}

824

}

825

return -1;

826

}

827

}

828

829

ret = init_gnutls_session(&session, mc);

661

830

if(ret != 0){

662

831

return -1;

663

832

}

682

851

683

852

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

684

853

if(af == AF_INET6){

685

to.in6.sin6_family = (sa_family_t)af;

686

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

854

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

855

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

687

856

} else { /* IPv4 */

688

to.in.sin_family = (sa_family_t)af;

689

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

857

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

858

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

690

859

}

691

860

if(ret < 0 ){

692

861

int e = errno;

701

870

goto mandos_end;

702

871

}

703

872

if(af == AF_INET6){

704

to.in6.sin6_port = htons(port);

705

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

706

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

707

-Wunreachable-code*/

873

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

874

if(IN6_IS_ADDR_LINKLOCAL

875

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

708

876

if(if_index == AVAHI_IF_UNSPEC){

709

877

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

710

878

" incomplete without a network interface\n");

712

880

goto mandos_end;

713

881

}

714

882

/* Set the network interface number as scope */

715

to.in6.sin6_scope_id = (uint32_t)if_index;

883

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

716

884

}

717

885

} else {

718

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

719

-Wconversion and

720

-Wunreachable-code */

886

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

721

887

}

722

888

723

889

if(quit_now){

740

906

}

741

907

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

742

908

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

743

const char *pcret;

744

909

if(af == AF_INET6){

745

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

746

sizeof(addrstr));

910

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

911

sizeof(struct sockaddr_in6),

912

addrstr, sizeof(addrstr), NULL, 0,

913

NI_NUMERICHOST);

747

914

} else {

748

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

749

sizeof(addrstr));

915

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

916

sizeof(struct sockaddr_in),

917

addrstr, sizeof(addrstr), NULL, 0,

918

NI_NUMERICHOST);

750

919

}

751

if(pcret == NULL){

752

perror_plus("inet_ntop");

753

} else {

754

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

755

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

756

}

920

if(ret == EAI_SYSTEM){

921

perror_plus("getnameinfo");

922

} else if(ret != 0) {

923

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

924

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

925

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

757

926

}

758

927

}

759

928

763

932

}

764

933

765

934

if(af == AF_INET6){

766

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

935

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

936

sizeof(struct sockaddr_in6));

767

937

} else {

768

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

938

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

939

sizeof(struct sockaddr_in));

769

940

}

770

941

if(ret < 0){

771

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

942

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

772

943

int e = errno;

773

944

perror_plus("connect");

774

945

errno = e;

935

1106

if(buffer_length > 0){

936

1107

ssize_t decrypted_buffer_size;

937

1108

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

938

&decrypted_buffer);

1109

&decrypted_buffer, mc);

939

1110

if(decrypted_buffer_size >= 0){

940

1111

941

1112

written = 0;

989

1160

return retval;

990

1161

}

991

1162

1163

__attribute__((nonnull))

992

1164

static void resolve_callback(AvahiSServiceResolver *r,

993

1165

AvahiIfIndex interface,

994

1166

AvahiProtocol proto,

1002

1174

AVAHI_GCC_UNUSED AvahiStringList *txt,

1003

1175

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1004

1176

flags,

1005

AVAHI_GCC_UNUSED void* userdata){

1177

void *mc){

1006

1178

if(r == NULL){

1007

1179

return;

1008

1180

}

1011

1183

timed out */

1012

1184

1013

1185

if(quit_now){

1186

avahi_s_service_resolver_free(r);

1014

1187

return;

1015

1188

}

1016

1189

1020

1193

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

1021

1194

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

1022

1195

domain,

1023

avahi_strerror(avahi_server_errno(mc.server)));

1196

avahi_strerror(avahi_server_errno

1197

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

1024

1198

break;

1025

1199

1026

1200

case AVAHI_RESOLVER_FOUND:

1034

1208

}

1035

1209

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

1036

1210

interface,

1037

avahi_proto_to_af(proto));

1211

avahi_proto_to_af(proto),

1212

mc);

1038

1213

if(ret == 0){

1039

1214

avahi_simple_poll_quit(simple_poll);

1040

1215

} else {

1041

1216

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

1042

avahi_proto_to_af(proto))){

1217

avahi_proto_to_af(proto),

1218

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

1043

1219

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

1044

1220

" list\n", name);

1045

1221

}

1058

1234

const char *domain,

1059

1235

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1060

1236

flags,

1061

AVAHI_GCC_UNUSED void* userdata){

1237

void *mc){

1062

1238

if(b == NULL){

1063

1239

return;

1064

1240

}

1075

1251

case AVAHI_BROWSER_FAILURE:

1076

1252

1077

1253

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

1078

avahi_strerror(avahi_server_errno(mc.server)));

1254

avahi_strerror(avahi_server_errno

1255

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

1079

1256

avahi_simple_poll_quit(simple_poll);

1080

1257

return;

1081

1258

1085

1262

the callback function is called the Avahi server will free the

1086

1263

resolver for us. */

1087

1264

1088

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

1089

name, type, domain, protocol, 0,

1090

resolve_callback, NULL) == NULL)

1265

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

1266

interface, protocol, name, type,

1267

domain, protocol, 0,

1268

resolve_callback, mc) == NULL)

1091

1269

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

1092

1270

" %s\n", name,

1093

avahi_strerror(avahi_server_errno(mc.server)));

1271

avahi_strerror(avahi_server_errno

1272

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

1094

1273

break;

1095

1274

1096

1275

case AVAHI_BROWSER_REMOVE:

1121

1300

errno = old_errno;

1122

1301

}

1123

1302

1303

__attribute__((nonnull, warn_unused_result))

1124

1304

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

1125

1305

int ret;

1126

1306

error_t ret_errno;

1145

1325

return true;

1146

1326

}

1147

1327

1328

__attribute__((nonnull, warn_unused_result))

1148

1329

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

1149

1330

1150

1331

/* Reject the loopback device */

1192

1373

* corresponds to an acceptable network device.

1193

1374

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

1194

1375

*/

1376

__attribute__((nonnull, warn_unused_result))

1195

1377

int good_interface(const struct dirent *if_entry){

1196

1378

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

1197

1379

return 0;

1215

1397

/*

1216

1398

* This function determines if a network interface is up.

1217

1399

*/

1400

__attribute__((nonnull, warn_unused_result))

1218

1401

bool interface_is_up(const char *interface){

1219

1402

struct ifreq ifr;

1220

1403

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

1231

1414

/*

1232

1415

* This function determines if a network interface is running

1233

1416

*/

1417

__attribute__((nonnull, warn_unused_result))

1234

1418

bool interface_is_running(const char *interface){

1235

1419

struct ifreq ifr;

1236

1420

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

1244

1428

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

1245

1429

}

1246

1430

1431

__attribute__((nonnull, pure, warn_unused_result))

1247

1432

int notdotentries(const struct dirent *direntry){

1248

1433

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

1249

1434

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

1256

1441

}

1257

1442

1258

1443

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

1444

__attribute__((nonnull, warn_unused_result))

1259

1445

int runnable_hook(const struct dirent *direntry){

1260

1446

int ret;

1261

1447

size_t sret;

1269

1455

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

1270

1456

"abcdefghijklmnopqrstuvwxyz"

1271

1457

"0123456789"

1272

"_-");

1458

"_.-");

1273

1459

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

1274

1460

/* Contains non-allowed characters */

1275

1461

if(debug){

1279

1465

return 0;

1280

1466

}

1281

1467

1282

char *fullname = NULL;

1283

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

1284

if(ret < 0){

1285

perror_plus("asprintf");

1286

return 0;

1287

}

1288

1289

ret = stat(fullname, &st);

1468

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

1290

1469

if(ret == -1){

1291

1470

if(debug){

1292

1471

perror_plus("Could not stat hook");

1316

1495

return 1;

1317

1496

}

1318

1497

1319

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1498

__attribute__((nonnull, warn_unused_result))

1499

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1500

mandos_context *mc){

1320

1501

int ret;

1321

1502

struct timespec now;

1322

1503

struct timespec waited_time;

1323

1504

intmax_t block_time;

1324

1505

1325

1506

while(true){

1326

if(mc.current_server == NULL){

1327

if (debug){

1507

if(mc->current_server == NULL){

1508

if(debug){

1328

1509

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

1329

1510

" No timeout!\n");

1330

1511

}

1331

1512

ret = avahi_simple_poll_iterate(s, -1);

1332

1513

} else {

1333

if (debug){

1514

if(debug){

1334

1515

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

1335

1516

" it, or wait\n");

1336

1517

}

1343

1524

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

1344

1525

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

1345

1526

waited_time.tv_sec = (now.tv_sec

1346

- mc.current_server->last_seen.tv_sec);

1527

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

1347

1528

waited_time.tv_nsec = (now.tv_nsec

1348

- mc.current_server->last_seen.tv_nsec);

1529

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

1349

1530

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

1350

1531

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

1351

1532

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

1353

1534

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

1354

1535

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

1355

1536

1356

if (debug){

1537

if(debug){

1357

1538

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

1358

1539

block_time);

1359

1540

}

1360

1541

1361

1542

if(block_time <= 0){

1362

ret = start_mandos_communication(mc.current_server->ip,

1363

mc.current_server->port,

1364

mc.current_server->if_index,

1365

mc.current_server->af);

1543

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

1544

mc->current_server->port,

1545

mc->current_server->if_index,

1546

mc->current_server->af, mc);

1366

1547

if(ret == 0){

1367

avahi_simple_poll_quit(simple_poll);

1548

avahi_simple_poll_quit(s);

1368

1549

return 0;

1369

1550

}

1370

1551

ret = clock_gettime(CLOCK_MONOTONIC,

1371

&mc.current_server->last_seen);

1552

&mc->current_server->last_seen);

1372

1553

if(ret == -1){

1373

1554

perror_plus("clock_gettime");

1374

1555

return -1;

1375

1556

}

1376

mc.current_server = mc.current_server->next;

1557

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

1377

1558

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

1378

1559

servers, but don't block */

1379

1560

}

1381

1562

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

1382

1563

}

1383

1564

if(ret != 0){

1384

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

1565

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

1385

1566

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

1386

1567

}

1387

1568

}

1389

1570

}

1390

1571

1391

1572

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

1573

__attribute__((warn_unused_result))

1392

1574

error_t raise_privileges(void){

1393

1575

error_t old_errno = errno;

1394

1576

error_t ret_errno = 0;

1395

1577

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

1396

1578

ret_errno = errno;

1397

perror_plus("seteuid");

1398

1579

}

1399

1580

errno = old_errno;

1400

1581

return ret_errno;

1401

1582

}

1402

1583

1403

1584

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

1585

__attribute__((warn_unused_result))

1404

1586

error_t raise_privileges_permanently(void){

1405

1587

error_t old_errno = errno;

1406

1588

error_t ret_errno = raise_privileges();

1410

1592

}

1411

1593

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

1412

1594

ret_errno = errno;

1413

perror_plus("seteuid");

1414

1595

}

1415

1596

errno = old_errno;

1416

1597

return ret_errno;

1417

1598

}

1418

1599

1419

1600

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

1601

__attribute__((warn_unused_result))

1420

1602

error_t lower_privileges(void){

1421

1603

error_t old_errno = errno;

1422

1604

error_t ret_errno = 0;

1423

1605

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

1424

1606

ret_errno = errno;

1425

perror_plus("seteuid");

1426

1607

}

1427

1608

errno = old_errno;

1428

1609

return ret_errno;

1429

1610

}

1430

1611

1431

1612

/* Lower privileges permanently */

1613

__attribute__((warn_unused_result))

1432

1614

error_t lower_privileges_permanently(void){

1433

1615

error_t old_errno = errno;

1434

1616

error_t ret_errno = 0;

1435

1617

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

1436

1618

ret_errno = errno;

1437

perror_plus("setuid");

1438

1619

}

1439

1620

errno = old_errno;

1440

1621

return ret_errno;

1441

1622

}

1442

1623

1443

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

1624

__attribute__((nonnull))

1625

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

1444

1626

const float delay){

1445

struct dirent **direntries;

1627

struct dirent **direntries = NULL;

1628

if(hookdir_fd == -1){

1629

hookdir_fd = open(hookdir, O_RDONLY);

1630

if(hookdir_fd == -1){

1631

if(errno == ENOENT){

1632

if(debug){

1633

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

1634

" found\n", hookdir);

1635

}

1636

} else {

1637

perror_plus("open");

1638

}

1639

return;

1640

}

1641

}

1642

#ifdef __GLIBC__

1643

#if __GLIBC_PREREQ(2, 15)

1644

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

1645

runnable_hook, alphasort);

1646

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

1647

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

1648

alphasort);

1649

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

1650

#else /* not __GLIBC__ */

1651

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

1652

alphasort);

1653

#endif /* not __GLIBC__ */

1654

if(numhooks == -1){

1655

perror_plus("scandir");

1656

return;

1657

}

1446

1658

struct dirent *direntry;

1447

1659

int ret;

1448

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

1449

alphasort);

1450

if(numhooks == -1){

1451

if(errno == ENOENT){

1452

if(debug){

1453

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

1454

" found\n", hookdir);

1455

}

1456

} else {

1457

perror_plus("scandir");

1660

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

1661

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

1662

direntry = direntries[i];

1663

if(debug){

1664

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

1665

direntry->d_name);

1458

1666

}

1459

} else {

1460

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

1461

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

1462

direntry = direntries[i];

1463

char *fullname = NULL;

1464

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

1465

if(ret < 0){

1667

pid_t hook_pid = fork();

1668

if(hook_pid == 0){

1669

/* Child */

1670

/* Raise privileges */

1671

errno = raise_privileges_permanently();

1672

if(errno != 0){

1673

perror_plus("Failed to raise privileges");

1674

_exit(EX_NOPERM);

1675

}

1676

/* Set group */

1677

errno = 0;

1678

ret = setgid(0);

1679

if(ret == -1){

1680

perror_plus("setgid");

1681

_exit(EX_NOPERM);

1682

}

1683

/* Reset supplementary groups */

1684

errno = 0;

1685

ret = setgroups(0, NULL);

1686

if(ret == -1){

1687

perror_plus("setgroups");

1688

_exit(EX_NOPERM);

1689

}

1690

ret = dup2(devnull, STDIN_FILENO);

1691

if(ret == -1){

1692

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

1693

_exit(EX_OSERR);

1694

}

1695

ret = close(devnull);

1696

if(ret == -1){

1697

perror_plus("close");

1698

_exit(EX_OSERR);

1699

}

1700

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1701

if(ret == -1){

1702

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

1703

_exit(EX_OSERR);

1704

}

1705

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

1706

if(ret == -1){

1707

perror_plus("setenv");

1708

_exit(EX_OSERR);

1709

}

1710

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

1711

if(ret == -1){

1712

perror_plus("setenv");

1713

_exit(EX_OSERR);

1714

}

1715

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

1716

if(ret == -1){

1717

perror_plus("setenv");

1718

_exit(EX_OSERR);

1719

}

1720

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

1721

if(ret == -1){

1722

perror_plus("setenv");

1723

_exit(EX_OSERR);

1724

}

1725

char *delaystring;

1726

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

1727

if(ret == -1){

1466

1728

perror_plus("asprintf");

1467

continue;

1468

}

1469

if(debug){

1470

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

1471

direntry->d_name);

1472

}

1473

pid_t hook_pid = fork();

1474

if(hook_pid == 0){

1475

/* Child */

1476

/* Raise privileges */

1477

raise_privileges_permanently();

1478

/* Set group */

1479

errno = 0;

1480

ret = setgid(0);

1481

if(ret == -1){

1482

perror_plus("setgid");

1483

}

1484

/* Reset supplementary groups */

1485

errno = 0;

1486

ret = setgroups(0, NULL);

1487

if(ret == -1){

1488

perror_plus("setgroups");

1489

}

1490

dup2(devnull, STDIN_FILENO);

1491

close(devnull);

1492

dup2(STDERR_FILENO, STDOUT_FILENO);

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

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

1509

if(ret == -1){

1510

perror_plus("setenv");

1511

_exit(EX_OSERR);

1512

}

1513

char *delaystring;

1514

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

1515

if(ret == -1){

1516

perror_plus("asprintf");

1517

_exit(EX_OSERR);

1518

}

1519

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

1520

if(ret == -1){

1521

free(delaystring);

1522

perror_plus("setenv");

1523

_exit(EX_OSERR);

1524

}

1729

_exit(EX_OSERR);

1730

}

1731

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

1732

if(ret == -1){

1525

1733

free(delaystring);

1526

if(connect_to != NULL){

1527

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

1528

if(ret == -1){

1529

perror_plus("setenv");

1530

_exit(EX_OSERR);

1531

}

1532

}

1533

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

1534

perror_plus("execl");

1535

_exit(EXIT_FAILURE);

1536

}

1734

perror_plus("setenv");

1735

_exit(EX_OSERR);

1736

}

1737

free(delaystring);

1738

if(connect_to != NULL){

1739

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

1740

if(ret == -1){

1741

perror_plus("setenv");

1742

_exit(EX_OSERR);

1743

}

1744

}

1745

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

1746

if(hook_fd == -1){

1747

perror_plus("openat");

1748

_exit(EXIT_FAILURE);

1749

}

1750

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

1751

perror_plus("close");

1752

_exit(EXIT_FAILURE);

1753

}

1754

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

1755

environ) == -1){

1756

perror_plus("fexecve");

1757

_exit(EXIT_FAILURE);

1758

}

1759

} else {

1760

if(hook_pid == -1){

1761

perror_plus("fork");

1762

free(direntry);

1763

continue;

1764

}

1765

int status;

1766

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

1767

perror_plus("waitpid");

1768

free(direntry);

1769

continue;

1770

}

1771

if(WIFEXITED(status)){

1772

if(WEXITSTATUS(status) != 0){

1773

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

1774

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

1775

WEXITSTATUS(status));

1776

free(direntry);

1777

continue;

1778

}

1779

} else if(WIFSIGNALED(status)){

1780

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

1781

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

1782

WTERMSIG(status));

1783

free(direntry);

1784

continue;

1537

1785

} else {

1538

int status;

1539

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

1540

perror_plus("waitpid");

1541

free(fullname);

1542

continue;

1543

}

1544

if(WIFEXITED(status)){

1545

if(WEXITSTATUS(status) != 0){

1546

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

1547

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

1548

WEXITSTATUS(status));

1549

free(fullname);

1550

continue;

1551

}

1552

} else if(WIFSIGNALED(status)){

1553

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

1554

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

1555

WTERMSIG(status));

1556

free(fullname);

1557

continue;

1558

} else {

1559

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

1560

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

1561

free(fullname);

1562

continue;

1563

}

1564

}

1565

free(fullname);

1566

if(debug){

1567

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

1568

direntry->d_name);

1569

}

1570

}

1571

close(devnull);

1572

}

1573

return true;

1786

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

1787

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

1788

free(direntry);

1789

continue;

1790

}

1791

}

1792

if(debug){

1793

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

1794

direntry->d_name);

1795

}

1796

free(direntry);

1797

}

1798

free(direntries);

1799

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

1800

perror_plus("close");

1801

} else {

1802

hookdir_fd = -1;

1803

}

1804

close(devnull);

1574

1805

}

1575

1806

1807

__attribute__((nonnull, warn_unused_result))

1576

1808

error_t bring_up_interface(const char *const interface,

1577

1809

const float delay){

1578

int sd = -1;

1579

1810

error_t old_errno = errno;

1580

error_t ret_errno = 0;

1581

int ret, ret_setflags;

1811

int ret;

1582

1812

struct ifreq network;

1583

1813

unsigned int if_index = if_nametoindex(interface);

1584

1814

if(if_index == 0){

1593

1823

}

1594

1824

1595

1825

if(not interface_is_up(interface)){

1596

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

1826

error_t ret_errno = 0, ioctl_errno = 0;

1827

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

1597

1828

ret_errno = errno;

1598

1829

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

1599

1830

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

1831

errno = old_errno;

1600

1832

return ret_errno;

1601

1833

}

1602

network.ifr_flags |= IFF_UP;

1834

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

1603

1835

1604

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1605

if(sd < 0){

1836

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

1837

if(sd == -1){

1606

1838

ret_errno = errno;

1607

1839

perror_plus("socket");

1608

1840

errno = old_errno;

1609

1841

return ret_errno;

1610

1842

}

1611

1843

1612

1844

if(quit_now){

1613

close(sd);

1845

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

1846

if(ret == -1){

1847

perror_plus("close");

1848

}

1614

1849

errno = old_errno;

1615

1850

return EINTR;

1616

1851

}

1620

1855

interface);

1621

1856

}

1622

1857

1623

/* Raise priviliges */

1624

raise_privileges();

1858

/* Raise privileges */

1859

ret_errno = raise_privileges();

1860

if(ret_errno != 0){

1861

errno = ret_errno;

1862

perror_plus("Failed to raise privileges");

1863

}

1625

1864

1626

1865

#ifdef __linux__

1627

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1628

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

1629

int ret_linux = klogctl(8, NULL, 5);

1630

bool restore_loglevel = true;

1631

if(ret_linux == -1){

1632

restore_loglevel = false;

1633

perror_plus("klogctl");

1866

int ret_linux;

1867

bool restore_loglevel = false;

1868

if(ret_errno == 0){

1869

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1870

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

1871

ret_linux = klogctl(8, NULL, 5);

1872

if(ret_linux == -1){

1873

perror_plus("klogctl");

1874

} else {

1875

restore_loglevel = true;

1876

}

1634

1877

}

1635

1878

#endif /* __linux__ */

1636

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

1637

ret_errno = errno;

1879

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

1880

ioctl_errno = errno;

1638

1881

#ifdef __linux__

1639

1882

if(restore_loglevel){

1640

1883

ret_linux = klogctl(7, NULL, 0);

1644

1887

}

1645

1888

#endif /* __linux__ */

1646

1889

1647

/* Lower privileges */

1648

lower_privileges();

1890

/* If raise_privileges() succeeded above */

1891

if(ret_errno == 0){

1892

/* Lower privileges */

1893

ret_errno = lower_privileges();

1894

if(ret_errno != 0){

1895

errno = ret_errno;

1896

perror_plus("Failed to lower privileges");

1897

}

1898

}

1649

1899

1650

1900

/* Close the socket */

1651

1901

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

1654

1904

}

1655

1905

1656

1906

if(ret_setflags == -1){

1657

errno = ret_errno;

1907

errno = ioctl_errno;

1658

1908

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1659

1909

errno = old_errno;

1660

return ret_errno;

1910

return ioctl_errno;

1661

1911

}

1662

1912

} else if(debug){

1663

1913

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

1681

1931

return 0;

1682

1932

}

1683

1933

1934

__attribute__((nonnull, warn_unused_result))

1684

1935

error_t take_down_interface(const char *const interface){

1685

int sd = -1;

1686

1936

error_t old_errno = errno;

1687

error_t ret_errno = 0;

1688

int ret, ret_setflags;

1689

1937

struct ifreq network;

1690

1938

unsigned int if_index = if_nametoindex(interface);

1691

1939

if(if_index == 0){

1694

1942

return ENXIO;

1695

1943

}

1696

1944

if(interface_is_up(interface)){

1945

error_t ret_errno = 0, ioctl_errno = 0;

1697

1946

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

1698

1947

ret_errno = errno;

1699

1948

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

1700

1949

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

1950

errno = old_errno;

1701

1951

return ret_errno;

1702

1952

}

1703

1953

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

1704

1954

1705

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1706

if(sd < 0){

1955

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

1956

if(sd == -1){

1707

1957

ret_errno = errno;

1708

1958

perror_plus("socket");

1709

1959

errno = old_errno;

1715

1965

interface);

1716

1966

}

1717

1967

1718

/* Raise priviliges */

1719

raise_privileges();

1720

1721

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

1722

ret_errno = errno;

1723

1724

/* Lower privileges */

1725

lower_privileges();

1968

/* Raise privileges */

1969

ret_errno = raise_privileges();

1970

if(ret_errno != 0){

1971

errno = ret_errno;

1972

perror_plus("Failed to raise privileges");

1973

}

1974

1975

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

1976

ioctl_errno = errno;

1977

1978

/* If raise_privileges() succeeded above */

1979

if(ret_errno == 0){

1980

/* Lower privileges */

1981

ret_errno = lower_privileges();

1982

if(ret_errno != 0){

1983

errno = ret_errno;

1984

perror_plus("Failed to lower privileges");

1985

}

1986

}

1726

1987

1727

1988

/* Close the socket */

1728

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

1989

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

1729

1990

if(ret == -1){

1730

1991

perror_plus("close");

1731

1992

}

1732

1993

1733

1994

if(ret_setflags == -1){

1734

errno = ret_errno;

1995

errno = ioctl_errno;

1735

1996

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1736

1997

errno = old_errno;

1737

return ret_errno;

1998

return ioctl_errno;

1738

1999

}

1739

2000

} else if(debug){

1740

2001

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

1746

2007

}

1747

2008

1748

2009

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

2010

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

2011

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

2012

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

2013

.interfaces = NULL, .interfaces_size = 0 };

1749

2014

AvahiSServiceBrowser *sb = NULL;

1750

2015

error_t ret_errno;

1751

2016

int ret;

1752

2017

intmax_t tmpmax;

1753

2018

char *tmp;

1754

2019

int exitcode = EXIT_SUCCESS;

1755

char *interfaces = NULL;

1756

size_t interfaces_size = 0;

1757

2020

char *interfaces_to_take_down = NULL;

1758

2021

size_t interfaces_to_take_down_size = 0;

1759

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

1760

bool tempdir_created = false;

2022

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

2023

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

2024

char *tempdir = NULL;

1761

2025

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1762

2026

const char *seckey = PATHDIR "/" SECKEY;

1763

2027

const char *pubkey = PATHDIR "/" PUBKEY;

1764

2028

char *interfaces_hooks = NULL;

1765

size_t interfaces_hooks_size = 0;

1766

2029

1767

2030

bool gnutls_initialized = false;

1768

2031

bool gpgme_initialized = false;

1859

2122

connect_to = arg;

1860

2123

break;

1861

2124

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

1862

ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,

1863

(int)',');

2125

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

2126

arg, (int)',');

1864

2127

if(ret_errno != 0){

1865

2128

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

1866

2129

}

1946

2209

/* Work around Debian bug #633582:

1947

2210

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

1948

2211

1949

/* Re-raise priviliges */

1950

if(raise_privileges() == 0){

2212

/* Re-raise privileges */

2213

ret_errno = raise_privileges();

2214

if(ret_errno != 0){

2215

errno = ret_errno;

2216

perror_plus("Failed to raise privileges");

2217

} else {

1951

2218

struct stat st;

1952

2219

1953

2220

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

1993

2260

}

1994

2261

1995

2262

/* Lower privileges */

1996

errno = 0;

1997

ret = seteuid(uid);

1998

if(ret == -1){

1999

perror_plus("seteuid");

2263

ret_errno = lower_privileges();

2264

if(ret_errno != 0){

2265

errno = ret_errno;

2266

perror_plus("Failed to lower privileges");

2000

2267

}

2001

2268

}

2002

2269

}

2003

2270

2004

/* Remove empty interface names */

2271

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

2005

2272

{

2006

2273

char *interface = NULL;

2007

while((interface = argz_next(interfaces, interfaces_size,

2274

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

2008

2275

interface))){

2009

if(if_nametoindex(interface) == 0){

2010

if(interface[0] != '\0' and strcmp(interface, "none") != 0){

2276

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

2277

and if_nametoindex(interface) == 0){

2278

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

2011

2279

fprintf_plus(stderr, "Not using nonexisting interface"

2012

2280

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

2013

2281

}

2014

argz_delete(&interfaces, &interfaces_size, interface);

2282

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

2015

2283

interface = NULL;

2016

2284

}

2017

2285

}

2019

2287

2020

2288

/* Run network hooks */

2021

2289

{

2022

2023

if(interfaces != NULL){

2024

interfaces_hooks = malloc(interfaces_size);

2290

if(mc.interfaces != NULL){

2291

interfaces_hooks = malloc(mc.interfaces_size);

2025

2292

if(interfaces_hooks == NULL){

2026

2293

perror_plus("malloc");

2027

2294

goto end;

2028

2295

}

2029

memcpy(interfaces_hooks, interfaces, interfaces_size);

2030

interfaces_hooks_size = interfaces_size;

2031

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2032

(int)',');

2033

}

2034

if(not run_network_hooks("start", interfaces_hooks != NULL ?

2035

interfaces_hooks : "", delay)){

2036

goto end;

2037

}

2296

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

2297

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

2298

}

2299

run_network_hooks("start", interfaces_hooks != NULL ?

2300

interfaces_hooks : "", delay);

2038

2301

}

2039

2302

2040

2303

if(not debug){

2117

2380

}

2118

2381

2119

2382

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

2120

if(interfaces == NULL){

2121

struct dirent **direntries;

2383

if(mc.interfaces == NULL){

2384

struct dirent **direntries = NULL;

2122

2385

/* Look for any good interfaces */

2123

2386

ret = scandir(sys_class_net, &direntries, good_interface,

2124

2387

alphasort);

2125

2388

if(ret >= 1){

2126

2389

/* Add all found interfaces to interfaces list */

2127

2390

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

2128

ret_errno = argz_add(&interfaces, &interfaces_size,

2391

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

2129

2392

direntries[i]->d_name);

2130

2393

if(ret_errno != 0){

2394

errno = ret_errno;

2131

2395

perror_plus("argz_add");

2396

free(direntries[i]);

2132

2397

continue;

2133

2398

}

2134

2399

if(debug){

2135

2400

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

2136

2401

direntries[i]->d_name);

2137

2402

}

2403

free(direntries[i]);

2138

2404

}

2139

2405

free(direntries);

2140

2406

} else {

2141

free(direntries);

2407

if(ret == 0){

2408

free(direntries);

2409

}

2142

2410

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

2143

2411

exitcode = EXIT_FAILURE;

2144

2412

goto end;

2145

2413

}

2146

2414

}

2147

2415

2148

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

2149

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

2150

if(debug){

2151

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

2152

interfaces);

2153

}

2154

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2155

}

2156

2157

/* Bring up interfaces which are down */

2158

if(not (argz_count(interfaces, interfaces_size) == 1

2159

and strcmp(interfaces, "none") == 0)){

2416

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

2417

{

2160

2418

char *interface = NULL;

2161

while((interface = argz_next(interfaces, interfaces_size,

2419

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

2162

2420

interface))){

2421

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

2422

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

2423

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

2424

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

2425

interface);

2426

interface = NULL;

2427

while((interface = argz_next(mc.interfaces,

2428

mc.interfaces_size, interface))){

2429

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

2430

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

2431

interface);

2432

interface = NULL;

2433

}

2434

}

2435

break;

2436

}

2163

2437

bool interface_was_up = interface_is_up(interface);

2164

ret = bring_up_interface(interface, delay);

2438

errno = bring_up_interface(interface, delay);

2165

2439

if(not interface_was_up){

2166

if(ret != 0){

2167

errno = ret;

2440

if(errno != 0){

2168

2441

perror_plus("Failed to bring up interface");

2169

2442

} else {

2170

ret_errno = argz_add(&interfaces_to_take_down,

2171

&interfaces_to_take_down_size,

2172

interface);

2443

errno = argz_add(&interfaces_to_take_down,

2444

&interfaces_to_take_down_size,

2445

interface);

2446

if(errno != 0){

2447

perror_plus("argz_add");

2448

}

2173

2449

}

2174

2450

}

2175

2451

}

2176

free(interfaces);

2177

interfaces = NULL;

2178

interfaces_size = 0;

2179

2452

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

2180

2453

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

2181

2454

}

2182

2455

}

2183

2456

2457

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

2458

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

2459

if(debug){

2460

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

2461

mc.interfaces);

2462

}

2463

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

2464

}

2465

2184

2466

if(quit_now){

2185

2467

goto end;

2186

2468

}

2187

2469

2188

ret = init_gnutls_global(pubkey, seckey);

2470

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

2189

2471

if(ret == -1){

2190

2472

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

2191

2473

exitcode = EX_UNAVAILABLE;

2198

2480

goto end;

2199

2481

}

2200

2482

2201

if(mkdtemp(tempdir) == NULL){

2483

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

2484

tempdir = mkdtemp(run_tempdir);

2485

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

2486

if(debug){

2487

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

2488

run_tempdir, old_tempdir);

2489

}

2490

tempdir = mkdtemp(old_tempdir);

2491

}

2492

if(tempdir == NULL){

2202

2493

perror_plus("mkdtemp");

2203

2494

goto end;

2204

2495

}

2205

tempdir_created = true;

2206

2496

2207

2497

if(quit_now){

2208

2498

goto end;

2209

2499

}

2210

2500

2211

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

2501

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

2212

2502

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

2213

2503

exitcode = EX_UNAVAILABLE;

2214

2504

goto end;

2244

2534

exitcode = EX_USAGE;

2245

2535

goto end;

2246

2536

}

2247

2537

2248

2538

if(quit_now){

2249

2539

goto end;

2250

2540

}

2271

2561

}

2272

2562

2273

2563

while(not quit_now){

2274

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

2564

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

2565

&mc);

2275

2566

if(quit_now or ret == 0){

2276

2567

break;

2277

2568

}

2279

2570

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

2280

2571

(int)retry_interval);

2281

2572

}

2282

sleep((int)retry_interval);

2573

sleep((unsigned int)retry_interval);

2283

2574

}

2284

2575

2285

if (not quit_now){

2576

if(not quit_now){

2286

2577

exitcode = EXIT_SUCCESS;

2287

2578

}

2288

2579

2325

2616

/* Create the Avahi service browser */

2326

2617

sb = avahi_s_service_browser_new(mc.server, if_index,

2327

2618

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2328

NULL, 0, browse_callback, NULL);

2619

NULL, 0, browse_callback,

2620

(void *)&mc);

2329

2621

if(sb == NULL){

2330

2622

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

2331

2623

avahi_strerror(avahi_server_errno(mc.server)));

2342

2634

if(debug){

2343

2635

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

2344

2636

}

2345

2637

2346

2638

ret = avahi_loop_with_timeout(simple_poll,

2347

(int)(retry_interval * 1000));

2639

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

2348

2640

if(debug){

2349

2641

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

2350

2642

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

2357

2649

}

2358

2650

2359

2651

/* Cleanup things */

2652

free(mc.interfaces);

2653

2360

2654

if(sb != NULL)

2361

2655

avahi_s_service_browser_free(sb);

2362

2656

2382

2676

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

2383

2677

while(mc.current_server != NULL){

2384

2678

server *next = mc.current_server->next;

2679

#ifdef __GNUC__

2680

#pragma GCC diagnostic push

2681

#pragma GCC diagnostic ignored "-Wcast-qual"

2682

#endif

2683

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

2684

#ifdef __GNUC__

2685

#pragma GCC diagnostic pop

2686

#endif

2385

2687

free(mc.current_server);

2386

2688

mc.current_server = next;

2387

2689

}

2388

2690

}

2389

2691

2390

/* Re-raise priviliges */

2692

/* Re-raise privileges */

2391

2693

{

2392

raise_privileges();

2393

2394

/* Run network hooks */

2395

run_network_hooks("stop", interfaces_hooks != NULL ?

2396

interfaces_hooks : "", delay);

2397

2398

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

2399

{

2400

char *interface = NULL;

2401

while((interface=argz_next(interfaces_to_take_down,

2402

interfaces_to_take_down_size,

2403

interface))){

2404

ret_errno = take_down_interface(interface);

2405

if(ret_errno != 0){

2406

errno = ret_errno;

2407

perror_plus("Failed to take down interface");

2408

}

2409

}

2410

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

2411

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

2412

" down\n");

2413

}

2414

}

2415

2416

lower_privileges_permanently();

2694

ret_errno = raise_privileges();

2695

if(ret_errno != 0){

2696

errno = ret_errno;

2697

perror_plus("Failed to raise privileges");

2698

} else {

2699

2700

/* Run network hooks */

2701

run_network_hooks("stop", interfaces_hooks != NULL ?

2702

interfaces_hooks : "", delay);

2703

2704

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

2705

{

2706

char *interface = NULL;

2707

while((interface=argz_next(interfaces_to_take_down,

2708

interfaces_to_take_down_size,

2709

interface))){

2710

ret_errno = take_down_interface(interface);

2711

if(ret_errno != 0){

2712

errno = ret_errno;

2713

perror_plus("Failed to take down interface");

2714

}

2715

}

2716

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

2717

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

2718

" down\n");

2719

}

2720

}

2721

}

2722

2723

ret_errno = lower_privileges_permanently();

2724

if(ret_errno != 0){

2725

errno = ret_errno;

2726

perror_plus("Failed to lower privileges permanently");

2727

}

2417

2728

}

2418

2729

2419

2730

free(interfaces_to_take_down);

2420

2731

free(interfaces_hooks);

2421

2732

2422

2733

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

2423

if(tempdir_created){

2734

if(tempdir != NULL){

2424

2735

struct dirent **direntries = NULL;

2425

struct dirent *direntry = NULL;

2426

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

2427

alphasort);

2428

if (numentries > 0){

2429

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

2430

direntry = direntries[i];

2431

char *fullname = NULL;

2432

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

2433

direntry->d_name);

2434

if(ret < 0){

2435

perror_plus("asprintf");

2436

continue;

2437

}

2438

ret = remove(fullname);

2439

if(ret == -1){

2440

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

2441

strerror(errno));

2442

}

2443

free(fullname);

2736

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

2737

O_NOFOLLOW));

2738

if(tempdir_fd == -1){

2739

perror_plus("open");

2740

} else {

2741

#ifdef __GLIBC__

2742

#if __GLIBC_PREREQ(2, 15)

2743

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

2744

notdotentries, alphasort);

2745

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

2746

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

2747

alphasort);

2748

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

2749

#else /* not __GLIBC__ */

2750

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

2751

alphasort);

2752

#endif /* not __GLIBC__ */

2753

if(numentries >= 0){

2754

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

2755

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

2756

if(ret == -1){

2757

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

2758

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

2759

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

2760

}

2761

free(direntries[i]);

2762

}

2763

2764

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

2765

free(direntries);

2766

if(numentries == -1){

2767

perror_plus("scandir");

2768

}

2769

ret = rmdir(tempdir);

2770

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

2771

perror_plus("rmdir");

2772

}

2444

2773

}

2445

}

2446

2447

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

2448

free(direntries);

2449

if (numentries == -1){

2450

perror_plus("scandir");

2451

}

2452

ret = rmdir(tempdir);

2453

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

2454

perror_plus("rmdir");

2774

TEMP_FAILURE_RETRY(close(tempdir_fd));

2455

2775

}

2456

2776

}

2457

2777