/mandos/release : revision 237.22.4

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

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#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

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42

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

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stdout, ferror() */

43

stdout, ferror(), remove() */

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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getnameinfo() */

60

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

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inet_pton(), connect() */

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

61

60

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

62

61

*/

63

62

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

64

63

strtoimax() */

64

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

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

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program_invocation_short_name */

67

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

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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unlinkat() */

78

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

76

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

77

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

79

78

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

80

79

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

81

80

argp_state, struct argp,

93

92

argz_delete(), argz_append(),

94

93

argz_stringify(), argz_add(),

95

94

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

98

95

99

96

#ifdef __linux__

100

97

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

142

139

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

143

140

char *connect_to = NULL;

144

141

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

142

uid_t uid = 65534;

147

143

gid_t gid = 65534;

148

144

149

145

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

150

146

typedef struct server{

151

147

const char *ip;

152

in_port_t port;

148

uint16_t port;

153

149

AvahiIfIndex if_index;

154

150

int af;

155

151

struct timespec last_seen;

159

155

160

156

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

161

157

typedef struct {

158

AvahiSimplePoll *simple_poll;

162

159

AvahiServer *server;

163

160

gnutls_certificate_credentials_t cred;

164

161

unsigned int dh_bits;

166

163

const char *priority;

167

164

gpgme_ctx_t ctx;

168

165

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

171

166

} mandos_context;

172

167

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

168

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

169

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

170

.dh_bits = 1024, .priority = "SECURE256"

171

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

172

.current_server = NULL };

175

173

176

174

sig_atomic_t quit_now = 0;

177

175

int signal_received = 0;

185

183

perror(print_text);

186

184

}

187

185

188

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

186

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

189

187

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

190

188

va_list ap;

191

189

va_start (ap, format);

192

190

193

191

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

194

192

program_invocation_short_name));

195

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

193

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

196

194

}

197

195

198

196

/*

200

198

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

201

199

* "buffer_length" is how much is already used.

202

200

*/

203

__attribute__((nonnull, warn_unused_result))

204

201

size_t incbuffer(char **buffer, size_t buffer_length,

205

202

size_t buffer_capacity){

206

203

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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

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

205

if(buffer == NULL){

213

206

return 0;

214

207

}

215

*buffer = new_buf;

216

208

buffer_capacity += BUFFER_SIZE;

217

209

}

218

210

return buffer_capacity;

219

211

}

220

212

221

213

/* 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){

214

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

215

int af){

225

216

int ret;

226

217

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

227

218

if(new_server == NULL){

234

225

.af = af };

235

226

if(new_server->ip == NULL){

236

227

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

free(new_server->ip);

244

free(new_server);

245

228

return false;

246

229

}

247

230

/* Special case of first server */

248

if(*current_server == NULL){

231

if (mc.current_server == NULL){

249

232

new_server->next = new_server;

250

233

new_server->prev = new_server;

251

*current_server = new_server;

234

mc.current_server = new_server;

235

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

252

236

} else {

253

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

254

new_server->next = *current_server;

255

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

237

new_server->next = mc.current_server;

238

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

256

239

new_server->prev->next = new_server;

257

(*current_server)->prev = new_server;

240

mc.current_server->prev = new_server;

241

}

242

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

243

if(ret == -1){

244

perror_plus("clock_gettime");

245

return false;

258

246

}

259

247

return true;

260

248

}

262

250

/*

263

251

* Initialize GPGME.

264

252

*/

265

__attribute__((nonnull, warn_unused_result))

266

static bool init_gpgme(const char * const seckey,

267

const char * const pubkey,

268

const char * const tempdir,

269

mandos_context *mc){

253

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

254

const char *tempdir){

270

255

gpgme_error_t rc;

271

256

gpgme_engine_info_t engine_info;

272

257

258

273

259

/*

274

260

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

275

261

*/

276

bool import_key(const char * const filename){

262

bool import_key(const char *filename){

277

263

int ret;

278

264

int fd;

279

265

gpgme_data_t pgp_data;

291

277

return false;

292

278

}

293

279

294

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

280

rc = gpgme_op_import(mc.ctx, pgp_data);

295

281

if(rc != GPG_ERR_NO_ERROR){

296

282

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

297

283

gpgme_strsource(rc), gpgme_strerror(rc));

341

327

}

342

328

343

329

/* Create new GPGME "context" */

344

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

330

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

345

331

if(rc != GPG_ERR_NO_ERROR){

346

332

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

347

333

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

360

346

* Decrypt OpenPGP data.

361

347

* Returns -1 on error

362

348

*/

363

__attribute__((nonnull, warn_unused_result))

364

349

static ssize_t pgp_packet_decrypt(const char *cryptotext,

365

350

size_t crypto_size,

366

char **plaintext,

367

mandos_context *mc){

351

char **plaintext){

368

352

gpgme_data_t dh_crypto, dh_plain;

369

353

gpgme_error_t rc;

370

354

ssize_t ret;

396

380

397

381

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

398

382

data buffer */

399

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

383

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

400

384

if(rc != GPG_ERR_NO_ERROR){

401

385

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

402

386

gpgme_strsource(rc), gpgme_strerror(rc));

403

387

plaintext_length = -1;

404

388

if(debug){

405

389

gpgme_decrypt_result_t result;

406

result = gpgme_op_decrypt_result(mc->ctx);

390

result = gpgme_op_decrypt_result(mc.ctx);

407

391

if(result == NULL){

408

392

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

409

393

} else {

486

470

return plaintext_length;

487

471

}

488

472

489

__attribute__((warn_unused_result))

490

static const char *safer_gnutls_strerror(int value){

491

const char *ret = gnutls_strerror(value);

473

static const char * safer_gnutls_strerror(int value){

474

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

475

-Wunreachable-code */

492

476

if(ret == NULL)

493

477

ret = "(unknown)";

494

478

return ret;

495

479

}

496

480

497

481

/* GnuTLS log function callback */

498

__attribute__((nonnull))

499

482

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

500

483

const char* string){

501

484

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

502

485

}

503

486

504

__attribute__((nonnull, warn_unused_result))

505

487

static int init_gnutls_global(const char *pubkeyfilename,

506

const char *seckeyfilename,

507

mandos_context *mc){

488

const char *seckeyfilename){

508

489

int ret;

509

490

510

491

if(debug){

527

508

}

528

509

529

510

/* OpenPGP credentials */

530

ret = gnutls_certificate_allocate_credentials(&mc->cred);

511

ret = gnutls_certificate_allocate_credentials(&mc.cred);

531

512

if(ret != GNUTLS_E_SUCCESS){

532

513

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

533

514

safer_gnutls_strerror(ret));

543

524

}

544

525

545

526

ret = gnutls_certificate_set_openpgp_key_file

546

(mc->cred, pubkeyfilename, seckeyfilename,

527

(mc.cred, pubkeyfilename, seckeyfilename,

547

528

GNUTLS_OPENPGP_FMT_BASE64);

548

529

if(ret != GNUTLS_E_SUCCESS){

549

530

fprintf_plus(stderr,

555

536

}

556

537

557

538

/* GnuTLS server initialization */

558

ret = gnutls_dh_params_init(&mc->dh_params);

539

ret = gnutls_dh_params_init(&mc.dh_params);

559

540

if(ret != GNUTLS_E_SUCCESS){

560

541

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

561

542

" initialization: %s\n",

562

543

safer_gnutls_strerror(ret));

563

544

goto globalfail;

564

545

}

565

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

546

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

566

547

if(ret != GNUTLS_E_SUCCESS){

567

548

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

568

549

safer_gnutls_strerror(ret));

569

550

goto globalfail;

570

551

}

571

552

572

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

553

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

573

554

574

555

return 0;

575

556

576

557

globalfail:

577

558

578

gnutls_certificate_free_credentials(mc->cred);

559

gnutls_certificate_free_credentials(mc.cred);

579

560

gnutls_global_deinit();

580

gnutls_dh_params_deinit(mc->dh_params);

561

gnutls_dh_params_deinit(mc.dh_params);

581

562

return -1;

582

563

}

583

564

584

__attribute__((nonnull, warn_unused_result))

585

static int init_gnutls_session(gnutls_session_t *session,

586

mandos_context *mc){

565

static int init_gnutls_session(gnutls_session_t *session){

587

566

int ret;

588

567

/* GnuTLS session creation */

589

568

do {

601

580

{

602

581

const char *err;

603

582

do {

604

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

583

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

605

584

if(quit_now){

606

585

gnutls_deinit(*session);

607

586

return -1;

618

597

619

598

do {

620

599

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

621

mc->cred);

600

mc.cred);

622

601

if(quit_now){

623

602

gnutls_deinit(*session);

624

603

return -1;

634

613

/* ignore client certificate if any. */

635

614

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

636

615

637

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

616

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

638

617

639

618

return 0;

640

619

}

644

623

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

645

624

646

625

/* Called when a Mandos server is found */

647

__attribute__((nonnull, warn_unused_result))

648

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

626

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

649

627

AvahiIfIndex if_index,

650

int af, mandos_context *mc){

628

int af){

651

629

int ret, tcp_sd = -1;

652

630

ssize_t sret;

653

struct sockaddr_storage to;

631

union {

632

struct sockaddr_in in;

633

struct sockaddr_in6 in6;

634

} to;

654

635

char *buffer = NULL;

655

636

char *decrypted_buffer = NULL;

656

637

size_t buffer_length = 0;

680

661

return -1;

681

662

}

682

663

683

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

684

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

685

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

686

bool match = false;

687

{

688

char *interface = NULL;

689

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

690

interface))){

691

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

692

match = true;

693

break;

694

}

695

}

696

}

697

if(not match){

698

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

699

connect to the server */

700

if(debug){

701

char interface[IF_NAMESIZE];

702

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

703

perror_plus("if_indextoname");

704

} else {

705

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

706

" \"%s\"\n",

707

if_indextoname((unsigned int)if_index,

708

interface));

709

}

710

}

711

return -1;

712

}

713

}

714

715

ret = init_gnutls_session(&session, mc);

664

ret = init_gnutls_session(&session);

716

665

if(ret != 0){

717

666

return -1;

718

667

}

719

668

720

669

if(debug){

721

670

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

722

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

671

PRIu16 "\n", ip, port);

723

672

}

724

673

725

674

tcp_sd = socket(pf, SOCK_STREAM, 0);

737

686

738

687

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

739

688

if(af == AF_INET6){

740

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

741

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

689

to.in6.sin6_family = (sa_family_t)af;

690

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

742

691

} else { /* IPv4 */

743

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

744

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

692

to.in.sin_family = (sa_family_t)af;

693

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

745

694

}

746

695

if(ret < 0 ){

747

696

int e = errno;

756

705

goto mandos_end;

757

706

}

758

707

if(af == AF_INET6){

759

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

760

if(IN6_IS_ADDR_LINKLOCAL

761

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

708

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

709

-Wconversion and

710

-Wunreachable-code */

711

712

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

713

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

714

-Wunreachable-code*/

762

715

if(if_index == AVAHI_IF_UNSPEC){

763

716

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

764

717

" incomplete without a network interface\n");

766

719

goto mandos_end;

767

720

}

768

721

/* Set the network interface number as scope */

769

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

722

to.in6.sin6_scope_id = (uint32_t)if_index;

770

723

}

771

724

} else {

772

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

725

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

726

-Wconversion and

727

-Wunreachable-code */

773

728

}

774

729

775

730

if(quit_now){

783

738

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

784

739

perror_plus("if_indextoname");

785

740

} else {

786

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

787

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

741

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

742

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

788

743

}

789

744

} else {

790

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

791

ip, (uintmax_t)port);

745

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

746

ip, port);

792

747

}

793

748

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

794

749

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

750

const char *pcret;

795

751

if(af == AF_INET6){

796

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

797

sizeof(struct sockaddr_in6),

798

addrstr, sizeof(addrstr), NULL, 0,

799

NI_NUMERICHOST);

752

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

753

sizeof(addrstr));

800

754

} else {

801

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

802

sizeof(struct sockaddr_in),

803

addrstr, sizeof(addrstr), NULL, 0,

804

NI_NUMERICHOST);

755

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

756

sizeof(addrstr));

805

757

}

806

if(ret == EAI_SYSTEM){

807

perror_plus("getnameinfo");

808

} else if(ret != 0) {

809

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

810

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

811

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

758

if(pcret == NULL){

759

perror_plus("inet_ntop");

760

} else {

761

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

762

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

763

}

812

764

}

813

765

}

814

766

818

770

}

819

771

820

772

if(af == AF_INET6){

821

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

822

sizeof(struct sockaddr_in6));

773

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

823

774

} else {

824

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

825

sizeof(struct sockaddr_in));

775

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

826

776

}

827

777

if(ret < 0){

828

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

778

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

829

779

int e = errno;

830

780

perror_plus("connect");

831

781

errno = e;

992

942

if(buffer_length > 0){

993

943

ssize_t decrypted_buffer_size;

994

944

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

995

&decrypted_buffer, mc);

945

&decrypted_buffer);

996

946

if(decrypted_buffer_size >= 0){

997

947

998

948

written = 0;

1046

996

return retval;

1047

997

}

1048

998

1049

__attribute__((nonnull))

1050

999

static void resolve_callback(AvahiSServiceResolver *r,

1051

1000

AvahiIfIndex interface,

1052

1001

AvahiProtocol proto,

1060

1009

AVAHI_GCC_UNUSED AvahiStringList *txt,

1061

1010

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1062

1011

flags,

1063

void *mc){

1064

if(r == NULL){

1065

return;

1066

}

1012

AVAHI_GCC_UNUSED void* userdata){

1013

assert(r);

1067

1014

1068

1015

/* Called whenever a service has been resolved successfully or

1069

1016

timed out */

1078

1025

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

1079

1026

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

1080

1027

domain,

1081

avahi_strerror(avahi_server_errno

1082

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

1028

avahi_strerror(avahi_server_errno(mc.server)));

1083

1029

break;

1084

1030

1085

1031

case AVAHI_RESOLVER_FOUND:

1091

1037

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

1092

1038

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

1093

1039

}

1094

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

1095

interface,

1096

avahi_proto_to_af(proto),

1097

mc);

1040

int ret = start_mandos_communication(ip, port, interface,

1041

avahi_proto_to_af(proto));

1098

1042

if(ret == 0){

1099

avahi_simple_poll_quit(simple_poll);

1043

avahi_simple_poll_quit(mc.simple_poll);

1100

1044

} else {

1101

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

1102

avahi_proto_to_af(proto),

1103

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

1045

if(not add_server(ip, port, interface,

1046

avahi_proto_to_af(proto))){

1104

1047

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

1105

1048

" list\n", name);

1106

1049

}

1119

1062

const char *domain,

1120

1063

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1121

1064

flags,

1122

void *mc){

1123

if(b == NULL){

1124

return;

1125

}

1065

AVAHI_GCC_UNUSED void* userdata){

1066

assert(b);

1126

1067

1127

1068

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

1128

1069

is removed from the LAN */

1136

1077

case AVAHI_BROWSER_FAILURE:

1137

1078

1138

1079

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

1139

avahi_strerror(avahi_server_errno

1140

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

1141

avahi_simple_poll_quit(simple_poll);

1080

avahi_strerror(avahi_server_errno(mc.server)));

1081

avahi_simple_poll_quit(mc.simple_poll);

1142

1082

return;

1143

1083

1144

1084

case AVAHI_BROWSER_NEW:

1147

1087

the callback function is called the Avahi server will free the

1148

1088

resolver for us. */

1149

1089

1150

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

1151

interface, protocol, name, type,

1152

domain, protocol, 0,

1153

resolve_callback, mc) == NULL)

1090

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

1091

name, type, domain, protocol, 0,

1092

resolve_callback, NULL) == NULL)

1154

1093

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

1155

1094

" %s\n", name,

1156

avahi_strerror(avahi_server_errno

1157

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

1095

avahi_strerror(avahi_server_errno(mc.server)));

1158

1096

break;

1159

1097

1160

1098

case AVAHI_BROWSER_REMOVE:

1179

1117

signal_received = sig;

1180

1118

int old_errno = errno;

1181

1119

/* set main loop to exit */

1182

if(simple_poll != NULL){

1183

avahi_simple_poll_quit(simple_poll);

1120

if(mc.simple_poll != NULL){

1121

avahi_simple_poll_quit(mc.simple_poll);

1184

1122

}

1185

1123

errno = old_errno;

1186

1124

}

1187

1125

1188

__attribute__((nonnull, warn_unused_result))

1189

1126

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

1190

1127

int ret;

1191

1128

error_t ret_errno;

1210

1147

return true;

1211

1148

}

1212

1149

1213

__attribute__((nonnull, warn_unused_result))

1214

1150

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

1215

1151

1216

1152

/* Reject the loopback device */

1258

1194

* corresponds to an acceptable network device.

1259

1195

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

1260

1196

*/

1261

__attribute__((nonnull, warn_unused_result))

1262

1197

int good_interface(const struct dirent *if_entry){

1263

1198

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

1264

1199

return 0;

1282

1217

/*

1283

1218

* This function determines if a network interface is up.

1284

1219

*/

1285

__attribute__((nonnull, warn_unused_result))

1286

1220

bool interface_is_up(const char *interface){

1287

1221

struct ifreq ifr;

1288

1222

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

1299

1233

/*

1300

1234

* This function determines if a network interface is running

1301

1235

*/

1302

__attribute__((nonnull, warn_unused_result))

1303

1236

bool interface_is_running(const char *interface){

1304

1237

struct ifreq ifr;

1305

1238

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

1313

1246

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

1314

1247

}

1315

1248

1316

__attribute__((nonnull, pure, warn_unused_result))

1317

1249

int notdotentries(const struct dirent *direntry){

1318

1250

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

1319

1251

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

1326

1258

}

1327

1259

1328

1260

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

1329

__attribute__((nonnull, warn_unused_result))

1330

1261

int runnable_hook(const struct dirent *direntry){

1331

1262

int ret;

1332

1263

size_t sret;

1340

1271

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

1341

1272

"abcdefghijklmnopqrstuvwxyz"

1342

1273

"0123456789"

1343

"_.-");

1274

"_-");

1344

1275

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

1345

1276

/* Contains non-allowed characters */

1346

1277

if(debug){

1350

1281

return 0;

1351

1282

}

1352

1283

1353

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);

1354

1292

if(ret == -1){

1355

1293

if(debug){

1356

1294

perror_plus("Could not stat hook");

1380

1318

return 1;

1381

1319

}

1382

1320

1383

__attribute__((nonnull, warn_unused_result))

1384

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1385

mandos_context *mc){

1321

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1386

1322

int ret;

1387

1323

struct timespec now;

1388

1324

struct timespec waited_time;

1389

1325

intmax_t block_time;

1390

1326

1391

1327

while(true){

1392

if(mc->current_server == NULL){

1393

if(debug){

1328

if(mc.current_server == NULL){

1329

if (debug){

1394

1330

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

1395

1331

" No timeout!\n");

1396

1332

}

1397

1333

ret = avahi_simple_poll_iterate(s, -1);

1398

1334

} else {

1399

if(debug){

1335

if (debug){

1400

1336

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

1401

1337

" it, or wait\n");

1402

1338

}

1409

1345

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

1410

1346

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

1411

1347

waited_time.tv_sec = (now.tv_sec

1412

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

1348

- mc.current_server->last_seen.tv_sec);

1413

1349

waited_time.tv_nsec = (now.tv_nsec

1414

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

1350

- mc.current_server->last_seen.tv_nsec);

1415

1351

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

1416

1352

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

1417

1353

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

1419

1355

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

1420

1356

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

1421

1357

1422

if(debug){

1358

if (debug){

1423

1359

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

1424

1360

block_time);

1425

1361

}

1426

1362

1427

1363

if(block_time <= 0){

1428

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

1429

mc->current_server->port,

1430

mc->current_server->if_index,

1431

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);

1432

1368

if(ret == 0){

1433

avahi_simple_poll_quit(s);

1369

avahi_simple_poll_quit(mc.simple_poll);

1434

1370

return 0;

1435

1371

}

1436

1372

ret = clock_gettime(CLOCK_MONOTONIC,

1437

&mc->current_server->last_seen);

1373

&mc.current_server->last_seen);

1438

1374

if(ret == -1){

1439

1375

perror_plus("clock_gettime");

1440

1376

return -1;

1441

1377

}

1442

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

1378

mc.current_server = mc.current_server->next;

1443

1379

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

1444

1380

servers, but don't block */

1445

1381

}

1447

1383

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

1448

1384

}

1449

1385

if(ret != 0){

1450

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

1386

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

1451

1387

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

1452

1388

}

1453

1389

}

1455

1391

}

1456

1392

1457

1393

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

1458

__attribute__((warn_unused_result))

1459

1394

error_t raise_privileges(void){

1460

1395

error_t old_errno = errno;

1461

1396

error_t ret_errno = 0;

1462

1397

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

1463

1398

ret_errno = errno;

1399

perror_plus("seteuid");

1464

1400

}

1465

1401

errno = old_errno;

1466

1402

return ret_errno;

1467

1403

}

1468

1404

1469

1405

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

1470

__attribute__((warn_unused_result))

1471

1406

error_t raise_privileges_permanently(void){

1472

1407

error_t old_errno = errno;

1473

1408

error_t ret_errno = raise_privileges();

1477

1412

}

1478

1413

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

1479

1414

ret_errno = errno;

1415

perror_plus("seteuid");

1480

1416

}

1481

1417

errno = old_errno;

1482

1418

return ret_errno;

1483

1419

}

1484

1420

1485

1421

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

1486

__attribute__((warn_unused_result))

1487

1422

error_t lower_privileges(void){

1488

1423

error_t old_errno = errno;

1489

1424

error_t ret_errno = 0;

1490

1425

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

1491

1426

ret_errno = errno;

1427

perror_plus("seteuid");

1492

1428

}

1493

1429

errno = old_errno;

1494

1430

return ret_errno;

1495

1431

}

1496

1432

1497

1433

/* Lower privileges permanently */

1498

__attribute__((warn_unused_result))

1499

1434

error_t lower_privileges_permanently(void){

1500

1435

error_t old_errno = errno;

1501

1436

error_t ret_errno = 0;

1502

1437

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

1503

1438

ret_errno = errno;

1439

perror_plus("setuid");

1504

1440

}

1505

1441

errno = old_errno;

1506

1442

return ret_errno;

1507

1443

}

1508

1444

1509

__attribute__((nonnull))

1510

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

1445

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

1511

1446

const float delay){

1512

struct dirent **direntries = NULL;

1513

if(hookdir_fd == -1){

1514

hookdir_fd = open(hookdir, O_RDONLY);

1515

if(hookdir_fd == -1){

1516

if(errno == ENOENT){

1517

if(debug){

1518

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

1519

" found\n", hookdir);

1520

}

1521

} else {

1522

perror_plus("open");

1523

}

1524

return;

1525

}

1526

}

1527

#ifdef __GLIBC__

1528

#if __GLIBC_PREREQ(2, 15)

1529

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

1530

runnable_hook, alphasort);

1531

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

1532

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

1533

alphasort);

1534

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

1535

#else /* not __GLIBC__ */

1536

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

1537

alphasort);

1538

#endif /* not __GLIBC__ */

1447

struct dirent **direntries;

1448

struct dirent *direntry;

1449

int ret;

1450

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

1451

alphasort);

1539

1452

if(numhooks == -1){

1540

1453

perror_plus("scandir");

1541

return;

1542

}

1543

struct dirent *direntry;

1544

int ret;

1545

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

1546

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

1547

direntry = direntries[i];

1548

if(debug){

1549

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

1550

direntry->d_name);

1551

}

1552

pid_t hook_pid = fork();

1553

if(hook_pid == 0){

1554

/* Child */

1555

/* Raise privileges */

1556

errno = raise_privileges_permanently();

1557

if(errno != 0){

1558

perror_plus("Failed to raise privileges");

1559

_exit(EX_NOPERM);

1560

}

1561

/* Set group */

1562

errno = 0;

1563

ret = setgid(0);

1564

if(ret == -1){

1565

perror_plus("setgid");

1566

_exit(EX_NOPERM);

1567

}

1568

/* Reset supplementary groups */

1569

errno = 0;

1570

ret = setgroups(0, NULL);

1571

if(ret == -1){

1572

perror_plus("setgroups");

1573

_exit(EX_NOPERM);

1574

}

1575

ret = dup2(devnull, STDIN_FILENO);

1576

if(ret == -1){

1577

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

1578

_exit(EX_OSERR);

1579

}

1580

ret = close(devnull);

1581

if(ret == -1){

1582

perror_plus("close");

1583

_exit(EX_OSERR);

1584

}

1585

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1586

if(ret == -1){

1587

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

1588

_exit(EX_OSERR);

1589

}

1590

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

1591

if(ret == -1){

1592

perror_plus("setenv");

1593

_exit(EX_OSERR);

1594

}

1595

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

1596

if(ret == -1){

1597

perror_plus("setenv");

1598

_exit(EX_OSERR);

1599

}

1600

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

1601

if(ret == -1){

1602

perror_plus("setenv");

1603

_exit(EX_OSERR);

1604

}

1605

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

1606

if(ret == -1){

1607

perror_plus("setenv");

1608

_exit(EX_OSERR);

1609

}

1610

char *delaystring;

1611

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

1612

if(ret == -1){

1454

} else {

1455

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

1456

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

1457

direntry = direntries[i];

1458

char *fullname = NULL;

1459

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

1460

if(ret < 0){

1613

1461

perror_plus("asprintf");

1614

_exit(EX_OSERR);

1615

}

1616

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

1617

if(ret == -1){

1462

continue;

1463

}

1464

if(debug){

1465

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

1466

direntry->d_name);

1467

}

1468

pid_t hook_pid = fork();

1469

if(hook_pid == 0){

1470

/* Child */

1471

/* Raise privileges */

1472

raise_privileges_permanently();

1473

/* Set group */

1474

errno = 0;

1475

ret = setgid(0);

1476

if(ret == -1){

1477

perror_plus("setgid");

1478

}

1479

/* Reset supplementary groups */

1480

errno = 0;

1481

ret = setgroups(0, NULL);

1482

if(ret == -1){

1483

perror_plus("setgroups");

1484

}

1485

dup2(devnull, STDIN_FILENO);

1486

close(devnull);

1487

dup2(STDERR_FILENO, STDOUT_FILENO);

1488

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

1489

if(ret == -1){

1490

perror_plus("setenv");

1491

_exit(EX_OSERR);

1492

}

1493

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

1494

if(ret == -1){

1495

perror_plus("setenv");

1496

_exit(EX_OSERR);

1497

}

1498

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

1499

if(ret == -1){

1500

perror_plus("setenv");

1501

_exit(EX_OSERR);

1502

}

1503

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

1504

if(ret == -1){

1505

perror_plus("setenv");

1506

_exit(EX_OSERR);

1507

}

1508

char *delaystring;

1509

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

1510

if(ret == -1){

1511

perror_plus("asprintf");

1512

_exit(EX_OSERR);

1513

}

1514

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

1515

if(ret == -1){

1516

free(delaystring);

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1618

1520

free(delaystring);

1619

perror_plus("setenv");

1620

_exit(EX_OSERR);

1621

}

1622

free(delaystring);

1623

if(connect_to != NULL){

1624

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

1625

if(ret == -1){

1626

perror_plus("setenv");

1627

_exit(EX_OSERR);

1628

}

1629

}

1630

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

1631

if(hook_fd == -1){

1632

perror_plus("openat");

1633

_exit(EXIT_FAILURE);

1634

}

1635

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

1636

perror_plus("close");

1637

_exit(EXIT_FAILURE);

1638

}

1639

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

1640

environ) == -1){

1641

perror_plus("fexecve");

1642

_exit(EXIT_FAILURE);

1643

}

1644

} else {

1645

int status;

1646

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

1647

perror_plus("waitpid");

1648

continue;

1649

}

1650

if(WIFEXITED(status)){

1651

if(WEXITSTATUS(status) != 0){

1652

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

1653

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

1654

WEXITSTATUS(status));

1655

continue;

1656

}

1657

} else if(WIFSIGNALED(status)){

1658

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

1659

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

1660

WTERMSIG(status));

1661

continue;

1521

if(connect_to != NULL){

1522

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

1523

if(ret == -1){

1524

perror_plus("setenv");

1525

_exit(EX_OSERR);

1526

}

1527

}

1528

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

1529

perror_plus("execl");

1530

_exit(EXIT_FAILURE);

1531

}

1662

1532

} else {

1663

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

1664

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

1665

continue;

1666

}

1667

}

1668

if(debug){

1669

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

1670

direntry->d_name);

1671

}

1672

}

1673

free(direntries);

1674

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

1675

perror_plus("close");

1676

} else {

1677

hookdir_fd = -1;

1678

}

1679

close(devnull);

1533

int status;

1534

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

1535

perror_plus("waitpid");

1536

free(fullname);

1537

continue;

1538

}

1539

if(WIFEXITED(status)){

1540

if(WEXITSTATUS(status) != 0){

1541

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

1542

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

1543

WEXITSTATUS(status));

1544

free(fullname);

1545

continue;

1546

}

1547

} else if(WIFSIGNALED(status)){

1548

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

1549

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

1550

WTERMSIG(status));

1551

free(fullname);

1552

continue;

1553

} else {

1554

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

1555

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

1556

free(fullname);

1557

continue;

1558

}

1559

}

1560

free(fullname);

1561

if(debug){

1562

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

1563

direntry->d_name);

1564

}

1565

}

1566

close(devnull);

1567

}

1568

return true;

1680

1569

}

1681

1570

1682

__attribute__((nonnull, warn_unused_result))

1683

1571

error_t bring_up_interface(const char *const interface,

1684

1572

const float delay){

1573

int sd = -1;

1685

1574

error_t old_errno = errno;

1686

int ret;

1575

error_t ret_errno = 0;

1576

int ret, ret_setflags;

1687

1577

struct ifreq network;

1688

1578

unsigned int if_index = if_nametoindex(interface);

1689

1579

if(if_index == 0){

1698

1588

}

1699

1589

1700

1590

if(not interface_is_up(interface)){

1701

error_t ret_errno = 0, ioctl_errno = 0;

1702

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

1591

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

1703

1592

ret_errno = errno;

1704

1593

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

1705

1594

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

1706

errno = old_errno;

1707

1595

return ret_errno;

1708

1596

}

1709

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

1597

network.ifr_flags |= IFF_UP;

1710

1598

1711

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

1712

if(sd == -1){

1599

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1600

if(sd < 0){

1713

1601

ret_errno = errno;

1714

1602

perror_plus("socket");

1715

1603

errno = old_errno;

1716

1604

return ret_errno;

1717

1605

}

1718

1606

1719

1607

if(quit_now){

1720

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

1721

if(ret == -1){

1722

perror_plus("close");

1723

}

1608

close(sd);

1724

1609

errno = old_errno;

1725

1610

return EINTR;

1726

1611

}

1730

1615

interface);

1731

1616

}

1732

1617

1733

/* Raise privileges */

1734

ret_errno = raise_privileges();

1735

if(ret_errno != 0){

1736

errno = ret_errno;

1737

perror_plus("Failed to raise privileges");

1738

}

1618

/* Raise priviliges */

1619

raise_privileges();

1739

1620

1740

1621

#ifdef __linux__

1741

int ret_linux;

1742

bool restore_loglevel = false;

1743

if(ret_errno == 0){

1744

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1745

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

1746

ret_linux = klogctl(8, NULL, 5);

1747

if(ret_linux == -1){

1748

perror_plus("klogctl");

1749

} else {

1750

restore_loglevel = true;

1751

}

1622

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1623

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

1624

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

1625

bool restore_loglevel = true;

1626

if(ret_linux == -1){

1627

restore_loglevel = false;

1628

perror_plus("klogctl");

1752

1629

}

1753

1630

#endif /* __linux__ */

1754

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

1755

ioctl_errno = errno;

1631

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

1632

ret_errno = errno;

1756

1633

#ifdef __linux__

1757

1634

if(restore_loglevel){

1758

1635

ret_linux = klogctl(7, NULL, 0);

1762

1639

}

1763

1640

#endif /* __linux__ */

1764

1641

1765

/* If raise_privileges() succeeded above */

1766

if(ret_errno == 0){

1767

/* Lower privileges */

1768

ret_errno = lower_privileges();

1769

if(ret_errno != 0){

1770

errno = ret_errno;

1771

perror_plus("Failed to lower privileges");

1772

}

1773

}

1642

/* Lower privileges */

1643

lower_privileges();

1774

1644

1775

1645

/* Close the socket */

1776

1646

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

1779

1649

}

1780

1650

1781

1651

if(ret_setflags == -1){

1782

errno = ioctl_errno;

1652

errno = ret_errno;

1783

1653

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1784

1654

errno = old_errno;

1785

return ioctl_errno;

1655

return ret_errno;

1786

1656

}

1787

1657

} else if(debug){

1788

1658

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

1806

1676

return 0;

1807

1677

}

1808

1678

1809

__attribute__((nonnull, warn_unused_result))

1810

1679

error_t take_down_interface(const char *const interface){

1680

int sd = -1;

1811

1681

error_t old_errno = errno;

1682

error_t ret_errno = 0;

1683

int ret, ret_setflags;

1812

1684

struct ifreq network;

1813

1685

unsigned int if_index = if_nametoindex(interface);

1814

1686

if(if_index == 0){

1817

1689

return ENXIO;

1818

1690

}

1819

1691

if(interface_is_up(interface)){

1820

error_t ret_errno = 0, ioctl_errno = 0;

1821

1692

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

1822

1693

ret_errno = errno;

1823

1694

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

1824

1695

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

1825

errno = old_errno;

1826

1696

return ret_errno;

1827

1697

}

1828

1698

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

1829

1699

1830

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

1831

if(sd == -1){

1700

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1701

if(sd < 0){

1832

1702

ret_errno = errno;

1833

1703

perror_plus("socket");

1834

1704

errno = old_errno;

1840

1710

interface);

1841

1711

}

1842

1712

1843

/* Raise privileges */

1844

ret_errno = raise_privileges();

1845

if(ret_errno != 0){

1846

errno = ret_errno;

1847

perror_plus("Failed to raise privileges");

1848

}

1849

1850

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

1851

ioctl_errno = errno;

1852

1853

/* If raise_privileges() succeeded above */

1854

if(ret_errno == 0){

1855

/* Lower privileges */

1856

ret_errno = lower_privileges();

1857

if(ret_errno != 0){

1858

errno = ret_errno;

1859

perror_plus("Failed to lower privileges");

1860

}

1861

}

1713

/* Raise priviliges */

1714

raise_privileges();

1715

1716

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

1717

ret_errno = errno;

1718

1719

/* Lower privileges */

1720

lower_privileges();

1862

1721

1863

1722

/* Close the socket */

1864

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

1723

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

1865

1724

if(ret == -1){

1866

1725

perror_plus("close");

1867

1726

}

1868

1727

1869

1728

if(ret_setflags == -1){

1870

errno = ioctl_errno;

1729

errno = ret_errno;

1871

1730

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1872

1731

errno = old_errno;

1873

return ioctl_errno;

1732

return ret_errno;

1874

1733

}

1875

1734

} else if(debug){

1876

1735

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

1882

1741

}

1883

1742

1884

1743

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

1885

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

1886

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

1887

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

1888

.interfaces = NULL, .interfaces_size = 0 };

1889

1744

AvahiSServiceBrowser *sb = NULL;

1890

1745

error_t ret_errno;

1891

1746

int ret;

1892

1747

intmax_t tmpmax;

1893

1748

char *tmp;

1894

1749

int exitcode = EXIT_SUCCESS;

1750

char *interfaces = NULL;

1751

size_t interfaces_size = 0;

1895

1752

char *interfaces_to_take_down = NULL;

1896

1753

size_t interfaces_to_take_down_size = 0;

1897

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

1898

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

1899

char *tempdir = NULL;

1754

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

1755

bool tempdir_created = false;

1900

1756

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1901

1757

const char *seckey = PATHDIR "/" SECKEY;

1902

1758

const char *pubkey = PATHDIR "/" PUBKEY;

1903

1759

char *interfaces_hooks = NULL;

1760

size_t interfaces_hooks_size = 0;

1904

1761

1905

1762

bool gnutls_initialized = false;

1906

1763

bool gpgme_initialized = false;

1997

1854

connect_to = arg;

1998

1855

break;

1999

1856

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

2000

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

2001

arg, (int)',');

1857

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

1858

(int)',');

2002

1859

if(ret_errno != 0){

2003

1860

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

2004

1861

}

2084

1941

/* Work around Debian bug #633582:

2085

1942

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

2086

1943

2087

/* Re-raise privileges */

2088

ret_errno = raise_privileges();

2089

if(ret_errno != 0){

2090

errno = ret_errno;

2091

perror_plus("Failed to raise privileges");

2092

} else {

1944

/* Re-raise priviliges */

1945

if(raise_privileges() == 0){

2093

1946

struct stat st;

2094

1947

2095

1948

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

2135

1988

}

2136

1989

2137

1990

/* Lower privileges */

2138

ret_errno = lower_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to lower privileges");

1991

errno = 0;

1992

ret = seteuid(uid);

1993

if(ret == -1){

1994

perror_plus("seteuid");

2142

1995

}

2143

1996

}

2144

1997

}

2145

1998

2146

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

1999

/* Remove empty interface names */

2147

2000

{

2148

2001

char *interface = NULL;

2149

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

2002

while((interface = argz_next(interfaces, interfaces_size,

2150

2003

interface))){

2151

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

2152

and if_nametoindex(interface) == 0){

2153

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

2004

if(if_nametoindex(interface) == 0){

2005

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

2154

2006

fprintf_plus(stderr, "Not using nonexisting interface"

2155

2007

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

2156

2008

}

2157

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

2009

argz_delete(&interfaces, &interfaces_size, interface);

2158

2010

interface = NULL;

2159

2011

}

2160

2012

}

2162

2014

2163

2015

/* Run network hooks */

2164

2016

{

2165

if(mc.interfaces != NULL){

2166

interfaces_hooks = malloc(mc.interfaces_size);

2167

if(interfaces_hooks == NULL){

2168

perror_plus("malloc");

2169

goto end;

2170

}

2171

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

2172

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

2173

}

2174

run_network_hooks("start", interfaces_hooks != NULL ?

2175

interfaces_hooks : "", delay);

2017

ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,

2018

interfaces, interfaces_size);

2019

if(ret_errno != 0){

2020

errno = ret_errno;

2021

perror_plus("argz_append");

2022

goto end;

2023

}

2024

argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');

2025

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

2026

goto end;

2027

}

2176

2028

}

2177

2029

2178

2030

if(not debug){

2183

2035

from the signal handler */

2184

2036

/* Initialize the pseudo-RNG for Avahi */

2185

2037

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

2186

simple_poll = avahi_simple_poll_new();

2187

if(simple_poll == NULL){

2038

mc.simple_poll = avahi_simple_poll_new();

2039

if(mc.simple_poll == NULL){

2188

2040

fprintf_plus(stderr,

2189

2041

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

2190

2042

exitcode = EX_UNAVAILABLE;

2255

2107

}

2256

2108

2257

2109

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

2258

if(mc.interfaces == NULL){

2259

struct dirent **direntries = NULL;

2110

if(interfaces == NULL){

2111

struct dirent **direntries;

2260

2112

/* Look for any good interfaces */

2261

2113

ret = scandir(sys_class_net, &direntries, good_interface,

2262

2114

alphasort);

2263

2115

if(ret >= 1){

2264

2116

/* Add all found interfaces to interfaces list */

2265

2117

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

2266

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

2118

ret_errno = argz_add(&interfaces, &interfaces_size,

2267

2119

direntries[i]->d_name);

2268

2120

if(ret_errno != 0){

2269

errno = ret_errno;

2270

2121

perror_plus("argz_add");

2271

2122

continue;

2272

2123

}

2277

2128

}

2278

2129

free(direntries);

2279

2130

} else {

2280

if(ret == 0){

2281

free(direntries);

2282

}

2131

free(direntries);

2283

2132

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

2284

2133

exitcode = EXIT_FAILURE;

2285

2134

goto end;

2286

2135

}

2287

2136

}

2288

2137

2289

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

2290

{

2138

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

2139

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

2140

if(debug){

2141

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

2142

interfaces);

2143

}

2144

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2145

}

2146

2147

/* Bring up interfaces which are down */

2148

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

2149

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

2291

2150

char *interface = NULL;

2292

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

2151

while((interface = argz_next(interfaces, interfaces_size,

2293

2152

interface))){

2294

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

2295

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

2296

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

2297

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

2298

interface);

2299

interface = NULL;

2300

while((interface = argz_next(mc.interfaces,

2301

mc.interfaces_size, interface))){

2302

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

2303

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

2304

interface);

2305

interface = NULL;

2306

}

2307

}

2308

break;

2309

}

2310

2153

bool interface_was_up = interface_is_up(interface);

2311

errno = bring_up_interface(interface, delay);

2154

ret = bring_up_interface(interface, delay);

2312

2155

if(not interface_was_up){

2313

if(errno != 0){

2156

if(ret != 0){

2157

errno = ret;

2314

2158

perror_plus("Failed to bring up interface");

2315

2159

} else {

2316

errno = argz_add(&interfaces_to_take_down,

2317

&interfaces_to_take_down_size,

2318

interface);

2319

if(errno != 0){

2320

perror_plus("argz_add");

2321

}

2160

ret_errno = argz_add(&interfaces_to_take_down,

2161

&interfaces_to_take_down_size,

2162

interface);

2322

2163

}

2323

2164

}

2324

2165

}

2166

free(interfaces);

2167

interfaces = NULL;

2168

interfaces_size = 0;

2325

2169

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

2326

2170

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

2327

2171

}

2328

2172

}

2329

2173

2330

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

2331

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

2332

if(debug){

2333

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

2334

mc.interfaces);

2335

}

2336

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

2337

}

2338

2339

2174

if(quit_now){

2340

2175

goto end;

2341

2176

}

2342

2177

2343

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

2178

ret = init_gnutls_global(pubkey, seckey);

2344

2179

if(ret == -1){

2345

2180

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

2346

2181

exitcode = EX_UNAVAILABLE;

2353

2188

goto end;

2354

2189

}

2355

2190

2356

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

2357

tempdir = mkdtemp(run_tempdir);

2358

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

2359

if(debug){

2360

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

2361

run_tempdir, old_tempdir);

2362

}

2363

tempdir = mkdtemp(old_tempdir);

2364

}

2365

if(tempdir == NULL){

2191

if(mkdtemp(tempdir) == NULL){

2366

2192

perror_plus("mkdtemp");

2367

2193

goto end;

2368

2194

}

2195

tempdir_created = true;

2369

2196

2370

2197

if(quit_now){

2371

2198

goto end;

2372

2199

}

2373

2200

2374

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

2201

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

2375

2202

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

2376

2203

exitcode = EX_UNAVAILABLE;

2377

2204

goto end;

2398

2225

goto end;

2399

2226

}

2400

2227

2401

in_port_t port;

2228

uint16_t port;

2402

2229

errno = 0;

2403

2230

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

2404

2231

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

2405

or tmpmax != (in_port_t)tmpmax){

2232

or tmpmax != (uint16_t)tmpmax){

2406

2233

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

2407

2234

exitcode = EX_USAGE;

2408

2235

goto end;

2409

2236

}

2410

2237

2411

2238

if(quit_now){

2412

2239

goto end;

2413

2240

}

2414

2241

2415

port = (in_port_t)tmpmax;

2242

port = (uint16_t)tmpmax;

2416

2243

*address = '\0';

2417

2244

/* Colon in address indicates IPv6 */

2418

2245

int af;

2434

2261

}

2435

2262

2436

2263

while(not quit_now){

2437

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

2438

&mc);

2264

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

2439

2265

if(quit_now or ret == 0){

2440

2266

break;

2441

2267

}

2443

2269

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

2444

2270

(int)retry_interval);

2445

2271

}

2446

sleep((unsigned int)retry_interval);

2272

sleep((int)retry_interval);

2447

2273

}

2448

2274

2449

if(not quit_now){

2275

if (not quit_now){

2450

2276

exitcode = EXIT_SUCCESS;

2451

2277

}

2452

2278

2467

2293

config.publish_domain = 0;

2468

2294

2469

2295

/* Allocate a new server */

2470

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2471

&config, NULL, NULL, &ret_errno);

2296

mc.server = avahi_server_new(avahi_simple_poll_get

2297

(mc.simple_poll), &config, NULL,

2298

NULL, &ret_errno);

2472

2299

2473

2300

/* Free the Avahi configuration data */

2474

2301

avahi_server_config_free(&config);

2489

2316

/* Create the Avahi service browser */

2490

2317

sb = avahi_s_service_browser_new(mc.server, if_index,

2491

2318

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2492

NULL, 0, browse_callback,

2493

(void *)&mc);

2319

NULL, 0, browse_callback, NULL);

2494

2320

if(sb == NULL){

2495

2321

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

2496

2322

avahi_strerror(avahi_server_errno(mc.server)));

2507

2333

if(debug){

2508

2334

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

2509

2335

}

2510

2511

ret = avahi_loop_with_timeout(simple_poll,

2512

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

2336

2337

ret = avahi_loop_with_timeout(mc.simple_poll,

2338

(int)(retry_interval * 1000));

2513

2339

if(debug){

2514

2340

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

2515

2341

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

2522

2348

}

2523

2349

2524

2350

/* Cleanup things */

2525

free(mc.interfaces);

2526

2527

2351

if(sb != NULL)

2528

2352

avahi_s_service_browser_free(sb);

2529

2353

2530

2354

if(mc.server != NULL)

2531

2355

avahi_server_free(mc.server);

2532

2356

2533

if(simple_poll != NULL)

2534

avahi_simple_poll_free(simple_poll);

2357

if(mc.simple_poll != NULL)

2358

avahi_simple_poll_free(mc.simple_poll);

2535

2359

2536

2360

if(gnutls_initialized){

2537

2361

gnutls_certificate_free_credentials(mc.cred);

2554

2378

}

2555

2379

}

2556

2380

2557

/* Re-raise privileges */

2381

/* Re-raise priviliges */

2558

2382

{

2559

ret_errno = raise_privileges();

2560

if(ret_errno != 0){

2561

errno = ret_errno;

2562

perror_plus("Failed to raise privileges");

2563

} else {

2564

2565

/* Run network hooks */

2566

run_network_hooks("stop", interfaces_hooks != NULL ?

2567

interfaces_hooks : "", delay);

2568

2569

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

2570

{

2571

char *interface = NULL;

2572

while((interface=argz_next(interfaces_to_take_down,

2573

interfaces_to_take_down_size,

2574

interface))){

2575

ret_errno = take_down_interface(interface);

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to take down interface");

2579

}

2580

}

2581

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

2582

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

2583

" down\n");

2584

}

2585

}

2586

}

2587

2588

ret_errno = lower_privileges_permanently();

2589

if(ret_errno != 0){

2590

errno = ret_errno;

2591

perror_plus("Failed to lower privileges permanently");

2592

}

2383

raise_privileges();

2384

2385

/* Run network hooks */

2386

run_network_hooks("stop", interfaces_hooks, delay);

2387

2388

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

2389

{

2390

char *interface = NULL;

2391

while((interface=argz_next(interfaces_to_take_down,

2392

interfaces_to_take_down_size,

2393

interface))){

2394

ret_errno = take_down_interface(interface);

2395

if(ret_errno != 0){

2396

errno = ret_errno;

2397

perror_plus("Failed to take down interface");

2398

}

2399

}

2400

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

2401

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

2402

" down\n");

2403

}

2404

}

2405

2406

lower_privileges_permanently();

2593

2407

}

2594

2408

2595

2409

free(interfaces_to_take_down);

2596

2410

free(interfaces_hooks);

2597

2411

2598

2412

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

2599

if(tempdir != NULL){

2413

if(tempdir_created){

2600

2414

struct dirent **direntries = NULL;

2601

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

2602

O_NOFOLLOW));

2603

if(tempdir_fd == -1){

2604

perror_plus("open");

2605

} else {

2606

#ifdef __GLIBC__

2607

#if __GLIBC_PREREQ(2, 15)

2608

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

2609

notdotentries, alphasort);

2610

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

2611

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

2612

alphasort);

2613

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

2614

#else /* not __GLIBC__ */

2615

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

2616

alphasort);

2617

#endif /* not __GLIBC__ */

2618

if(numentries >= 0){

2619

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

2620

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

2621

if(ret == -1){

2622

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

2623

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

2624

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

2625

}

2626

}

2627

2628

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

2629

free(direntries);

2630

if(numentries == -1){

2631

perror_plus("scandir");

2632

}

2633

ret = rmdir(tempdir);

2634

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

2635

perror_plus("rmdir");

2636

}

2415

struct dirent *direntry = NULL;

2416

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

2417

alphasort);

2418

if (numentries > 0){

2419

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

2420

direntry = direntries[i];

2421

char *fullname = NULL;

2422

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

2423

direntry->d_name);

2424

if(ret < 0){

2425

perror_plus("asprintf");

2426

continue;

2427

}

2428

ret = remove(fullname);

2429

if(ret == -1){

2430

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

2431

strerror(errno));

2432

}

2433

free(fullname);

2637

2434

}

2638

TEMP_FAILURE_RETRY(close(tempdir_fd));

2435

}

2436

2437

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

2438

free(direntries);

2439

if (numentries == -1){

2440

perror_plus("scandir");

2441

}

2442

ret = rmdir(tempdir);

2443

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

2444

perror_plus("rmdir");

2639

2445

}

2640

2446

}

2641

2447