/mandos/trunk : revision 923

9

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

10

*

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* Everything else is

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13

14

*

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

16

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

17

* published by the Free Software Foundation, either version 3 of the

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* License, or (at your option) any later version.

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*

20

* This program is distributed in the hope that it will be useful, but

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13

14

*

15

* This file is part of Mandos.

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*

17

* Mandos is free software: you can redistribute it and/or modify it

18

* under the terms of the GNU General Public License as published by

19

* the Free Software Foundation, either version 3 of the License, or

20

* (at your option) any later version.

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*

22

* Mandos is distributed in the hope that it will be useful, but

21

23

* WITHOUT ANY WARRANTY; without even the implied warranty of

22

24

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

23

25

* General Public License for more details.

24

26

*

25

27

* You should have received a copy of the GNU General Public License

26

* along with this program. If not, see

27

* <http://www.gnu.org/licenses/>.

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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.

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29

*

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30

* Contact the authors at <mandos@recompile.se>.

30

31

*/

32

33

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

33

34

#ifndef _LARGEFILE_SOURCE

34

35

#define _LARGEFILE_SOURCE

35

#endif

36

#endif /* not _LARGEFILE_SOURCE */

36

37

#ifndef _FILE_OFFSET_BITS

37

38

#define _FILE_OFFSET_BITS 64

38

#endif

39

#endif /* not _FILE_OFFSET_BITS */

39

40

41

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

41

42

43

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

43

stdout, ferror(), remove() */

44

stdout, ferror() */

44

45

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

45

46

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

46

47

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

47

48

strtof(), abort() */

48

49

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

49

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

50

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

50

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

51

asprintf(), strncpy(), strsignal()

52

*/

51

53

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

52

54

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

53

55

sockaddr_in6, PF_INET6,

57

59

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

58

60

inet_pton(), connect(),

59

61

getnameinfo() */

60

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

62

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

61

63

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

62

64

*/

63

65

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

64

66

strtoimax() */

65

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

67

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

68

EAI_SYSTEM, ENETUNREACH,

69

EHOSTUNREACH, ECONNREFUSED, EPROTO,

70

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

71

ENOTEMPTY,

66

72

program_invocation_short_name */

67

73

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

68

74

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

73

79

*/

74

80

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

75

81

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

76

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

82

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

83

unlinkat() */

77

84

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

78

85

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

79

86

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

141

148

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

142

149

char *connect_to = NULL;

143

150

const char *hookdir = HOOKDIR;

151

int hookdir_fd = -1;

144

152

uid_t uid = 65534;

145

153

gid_t gid = 65534;

146

154

183

191

perror(print_text);

184

192

}

185

193

186

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

194

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

187

195

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

188

196

va_list ap;

189

197

va_start (ap, format);

198

206

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

199

207

* "buffer_length" is how much is already used.

200

208

*/

209

__attribute__((nonnull, warn_unused_result))

201

210

size_t incbuffer(char **buffer, size_t buffer_length,

202

211

size_t buffer_capacity){

203

212

if(buffer_length + BUFFER_SIZE > buffer_capacity){

216

225

}

217

226

218

227

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

228

__attribute__((nonnull, warn_unused_result))

219

229

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

220

230

int af, server **current_server){

221

231

int ret;

230

240

.af = af };

231

241

if(new_server->ip == NULL){

232

242

perror_plus("strdup");

243

free(new_server);

233

244

return false;

234

245

}

235

246

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

236

247

if(ret == -1){

237

248

perror_plus("clock_gettime");

249

#ifdef __GNUC__

250

#pragma GCC diagnostic push

251

#pragma GCC diagnostic ignored "-Wcast-qual"

252

#endif

253

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

254

#ifdef __GNUC__

255

#pragma GCC diagnostic pop

256

#endif

257

free(new_server);

238

258

return false;

239

259

}

240

260

/* Special case of first server */

242

262

new_server->next = new_server;

243

263

new_server->prev = new_server;

244

264

*current_server = new_server;

245

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

246

265

} else {

266

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

247

267

new_server->next = *current_server;

248

268

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

249

269

new_server->prev->next = new_server;

255

275

/*

256

276

* Initialize GPGME.

257

277

*/

258

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

259

const char *tempdir, mandos_context *mc){

278

__attribute__((nonnull, warn_unused_result))

279

static bool init_gpgme(const char * const seckey,

280

const char * const pubkey,

281

const char * const tempdir,

282

mandos_context *mc){

260

283

gpgme_error_t rc;

261

284

gpgme_engine_info_t engine_info;

262

285

263

286

/*

264

287

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

265

288

*/

266

bool import_key(const char *filename){

289

bool import_key(const char * const filename){

267

290

int ret;

268

291

int fd;

269

292

gpgme_data_t pgp_data;

288

311

return false;

289

312

}

290

313

291

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

314

ret = close(fd);

292

315

if(ret == -1){

293

316

perror_plus("close");

294

317

}

350

373

* Decrypt OpenPGP data.

351

374

* Returns -1 on error

352

375

*/

376

__attribute__((nonnull, warn_unused_result))

353

377

static ssize_t pgp_packet_decrypt(const char *cryptotext,

354

378

size_t crypto_size,

355

379

char **plaintext,

475

499

return plaintext_length;

476

500

}

477

501

478

static const char * safer_gnutls_strerror(int value){

502

__attribute__((warn_unused_result, const))

503

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

504

if(str == NULL)

505

return "(unknown)";

506

return str;

507

}

508

509

__attribute__((warn_unused_result))

510

static const char *safer_gnutls_strerror(int value){

479

511

const char *ret = gnutls_strerror(value);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

512

return safe_string(ret);

483

513

}

484

514

485

515

/* GnuTLS log function callback */

516

__attribute__((nonnull))

486

517

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

487

518

const char* string){

488

519

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

489

520

}

490

521

522

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

491

523

static int init_gnutls_global(const char *pubkeyfilename,

492

524

const char *seckeyfilename,

525

const char *dhparamsfilename,

493

526

mandos_context *mc){

494

527

int ret;

528

unsigned int uret;

495

529

496

530

if(debug){

497

531

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

498

532

}

499

533

500

ret = gnutls_global_init();

501

if(ret != GNUTLS_E_SUCCESS){

502

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

503

safer_gnutls_strerror(ret));

504

return -1;

505

}

506

507

534

if(debug){

508

535

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

509

536

* - GnuTLS manual

517

544

if(ret != GNUTLS_E_SUCCESS){

518

545

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

519

546

safer_gnutls_strerror(ret));

520

gnutls_global_deinit();

521

547

return -1;

522

548

}

523

549

548

574

safer_gnutls_strerror(ret));

549

575

goto globalfail;

550

576

}

551

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

552

if(ret != GNUTLS_E_SUCCESS){

553

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

554

safer_gnutls_strerror(ret));

555

goto globalfail;

556

}

557

577

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

578

if(dhparamsfilename != NULL){

579

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

580

do {

581

int dhpfile = open(dhparamsfilename, O_RDONLY);

582

if(dhpfile == -1){

583

perror_plus("open");

584

dhparamsfilename = NULL;

585

break;

586

}

587

size_t params_capacity = 0;

588

while(true){

589

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

590

(size_t)params.size,

591

(size_t)params_capacity);

592

if(params_capacity == 0){

593

perror_plus("incbuffer");

594

free(params.data);

595

params.data = NULL;

596

dhparamsfilename = NULL;

597

break;

598

}

599

ssize_t bytes_read = read(dhpfile,

600

params.data + params.size,

601

BUFFER_SIZE);

602

/* EOF */

603

if(bytes_read == 0){

604

break;

605

}

606

/* check bytes_read for failure */

607

if(bytes_read < 0){

608

perror_plus("read");

609

free(params.data);

610

params.data = NULL;

611

dhparamsfilename = NULL;

612

break;

613

}

614

params.size += (unsigned int)bytes_read;

615

}

616

if(params.data == NULL){

617

dhparamsfilename = NULL;

618

}

619

if(dhparamsfilename == NULL){

620

break;

621

}

622

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

623

GNUTLS_X509_FMT_PEM);

624

if(ret != GNUTLS_E_SUCCESS){

625

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

626

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

627

safer_gnutls_strerror(ret));

628

dhparamsfilename = NULL;

629

}

630

free(params.data);

631

} while(false);

632

}

633

if(dhparamsfilename == NULL){

634

if(mc->dh_bits == 0){

635

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

636

/* Try to read the private key file */

637

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

638

do {

639

int secfile = open(seckeyfilename, O_RDONLY);

640

if(secfile == -1){

641

perror_plus("open");

642

break;

643

}

644

size_t buffer_capacity = 0;

645

while(true){

646

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

647

(size_t)buffer.size,

648

(size_t)buffer_capacity);

649

if(buffer_capacity == 0){

650

perror_plus("incbuffer");

651

free(buffer.data);

652

buffer.data = NULL;

653

break;

654

}

655

ssize_t bytes_read = read(secfile,

656

buffer.data + buffer.size,

657

BUFFER_SIZE);

658

/* EOF */

659

if(bytes_read == 0){

660

break;

661

}

662

/* check bytes_read for failure */

663

if(bytes_read < 0){

664

perror_plus("read");

665

free(buffer.data);

666

buffer.data = NULL;

667

break;

668

}

669

buffer.size += (unsigned int)bytes_read;

670

}

671

close(secfile);

672

} while(false);

673

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

674

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

675

if(buffer.data != NULL){

676

{

677

gnutls_openpgp_privkey_t privkey = NULL;

678

ret = gnutls_openpgp_privkey_init(&privkey);

679

if(ret != GNUTLS_E_SUCCESS){

680

fprintf_plus(stderr, "Error initializing OpenPGP key"

681

" structure: %s",

682

safer_gnutls_strerror(ret));

683

free(buffer.data);

684

buffer.data = NULL;

685

} else {

686

ret = gnutls_openpgp_privkey_import

687

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

688

if(ret != GNUTLS_E_SUCCESS){

689

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

690

safer_gnutls_strerror(ret));

691

privkey = NULL;

692

}

693

free(buffer.data);

694

buffer.data = NULL;

695

if(privkey != NULL){

696

/* Use private key to suggest an appropriate

697

sec_param */

698

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

699

gnutls_openpgp_privkey_deinit(privkey);

700

if(debug){

701

fprintf_plus(stderr, "This OpenPGP key implies using"

702

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

703

safe_string(gnutls_sec_param_get_name

704

(sec_param)));

705

}

706

}

707

}

708

}

709

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

710

/* Err on the side of caution */

711

sec_param = GNUTLS_SEC_PARAM_ULTRA;

712

if(debug){

713

fprintf_plus(stderr, "Falling back to security parameter"

714

" \"%s\"\n",

715

safe_string(gnutls_sec_param_get_name

716

(sec_param)));

717

}

718

}

719

}

720

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

721

if(uret != 0){

722

mc->dh_bits = uret;

723

if(debug){

724

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

725

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

726

safe_string(gnutls_sec_param_get_name

727

(sec_param)),

728

mc->dh_bits);

729

}

730

} else {

731

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

732

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

733

safe_string(gnutls_sec_param_get_name

734

(sec_param)),

735

safer_gnutls_strerror(ret));

736

goto globalfail;

737

}

738

} else if(debug){

739

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

740

mc->dh_bits);

741

}

742

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

743

if(ret != GNUTLS_E_SUCCESS){

744

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

745

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

746

safer_gnutls_strerror(ret));

747

goto globalfail;

748

}

749

}

558

750

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

559

751

560

752

return 0;

562

754

globalfail:

563

755

564

756

gnutls_certificate_free_credentials(mc->cred);

565

gnutls_global_deinit();

566

757

gnutls_dh_params_deinit(mc->dh_params);

567

758

return -1;

568

759

}

569

760

761

__attribute__((nonnull, warn_unused_result))

570

762

static int init_gnutls_session(gnutls_session_t *session,

571

763

mandos_context *mc){

572

764

int ret;

619

811

/* ignore client certificate if any. */

620

812

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

621

813

622

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

623

624

814

return 0;

625

815

}

626

816

628

818

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

629

819

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

630

820

821

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

822

__attribute__((warn_unused_result))

823

int raise_privileges(void){

824

int old_errno = errno;

825

int ret = 0;

826

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

827

ret = errno;

828

}

829

errno = old_errno;

830

return ret;

831

}

832

833

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

834

__attribute__((warn_unused_result))

835

int raise_privileges_permanently(void){

836

int old_errno = errno;

837

int ret = raise_privileges();

838

if(ret != 0){

839

errno = old_errno;

840

return ret;

841

}

842

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

843

ret = errno;

844

}

845

errno = old_errno;

846

return ret;

847

}

848

849

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

850

__attribute__((warn_unused_result))

851

int lower_privileges(void){

852

int old_errno = errno;

853

int ret = 0;

854

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

855

ret = errno;

856

}

857

errno = old_errno;

858

return ret;

859

}

860

861

/* Lower privileges permanently */

862

__attribute__((warn_unused_result))

863

int lower_privileges_permanently(void){

864

int old_errno = errno;

865

int ret = 0;

866

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

867

ret = errno;

868

}

869

errno = old_errno;

870

return ret;

871

}

872

873

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

874

__attribute__((nonnull, warn_unused_result))

875

static bool add_delete_local_route(const bool add,

876

const char *address,

877

AvahiIfIndex if_index){

878

int ret;

879

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

880

char add_arg[] = "add";

881

char delete_arg[] = "delete";

882

char debug_flag[] = "--debug";

883

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

884

if(pluginhelperdir == NULL){

885

if(debug){

886

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

887

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

888

}

889

return false;

890

}

891

892

char interface[IF_NAMESIZE];

893

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

894

perror_plus("if_indextoname");

895

return false;

896

}

897

898

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

899

if(devnull == -1){

900

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

901

return false;

902

}

903

pid_t pid = fork();

904

if(pid == 0){

905

/* Child */

906

/* Raise privileges */

907

errno = raise_privileges_permanently();

908

if(errno != 0){

909

perror_plus("Failed to raise privileges");

910

/* _exit(EX_NOPERM); */

911

} else {

912

/* Set group */

913

errno = 0;

914

ret = setgid(0);

915

if(ret == -1){

916

perror_plus("setgid");

917

_exit(EX_NOPERM);

918

}

919

/* Reset supplementary groups */

920

errno = 0;

921

ret = setgroups(0, NULL);

922

if(ret == -1){

923

perror_plus("setgroups");

924

_exit(EX_NOPERM);

925

}

926

}

927

ret = dup2(devnull, STDIN_FILENO);

928

if(ret == -1){

929

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

930

_exit(EX_OSERR);

931

}

932

ret = close(devnull);

933

if(ret == -1){

934

perror_plus("close");

935

_exit(EX_OSERR);

936

}

937

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

938

if(ret == -1){

939

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

940

_exit(EX_OSERR);

941

}

942

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

943

O_RDONLY

944

| O_DIRECTORY

945

| O_PATH

946

| O_CLOEXEC));

947

if(helperdir_fd == -1){

948

perror_plus("open");

949

_exit(EX_UNAVAILABLE);

950

}

951

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

952

helper, O_RDONLY));

953

if(helper_fd == -1){

954

perror_plus("openat");

955

close(helperdir_fd);

956

_exit(EX_UNAVAILABLE);

957

}

958

close(helperdir_fd);

959

#ifdef __GNUC__

960

#pragma GCC diagnostic push

961

#pragma GCC diagnostic ignored "-Wcast-qual"

962

#endif

963

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

964

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

965

interface, debug ? debug_flag : NULL, NULL },

966

environ) == -1){

967

#ifdef __GNUC__

968

#pragma GCC diagnostic pop

969

#endif

970

perror_plus("fexecve");

971

_exit(EXIT_FAILURE);

972

}

973

}

974

if(pid == -1){

975

perror_plus("fork");

976

return false;

977

}

978

int status;

979

pid_t pret = -1;

980

errno = 0;

981

do {

982

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

983

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

984

int errno_raising = 0;

985

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

986

errno_raising = errno;

987

perror_plus("Failed to raise privileges in order to"

988

" kill helper program");

989

}

990

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

991

perror_plus("kill");

992

}

993

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

994

perror_plus("Failed to lower privileges after killing"

995

" helper program");

996

}

997

return false;

998

}

999

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

1000

if(pret == -1){

1001

perror_plus("waitpid");

1002

return false;

1003

}

1004

if(WIFEXITED(status)){

1005

if(WEXITSTATUS(status) != 0){

1006

fprintf_plus(stderr, "Error: iprouteadddel exited"

1007

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

1008

return false;

1009

}

1010

return true;

1011

}

1012

if(WIFSIGNALED(status)){

1013

fprintf_plus(stderr, "Error: iprouteadddel died by"

1014

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

1015

return false;

1016

}

1017

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

1018

return false;

1019

}

1020

1021

__attribute__((nonnull, warn_unused_result))

1022

static bool add_local_route(const char *address,

1023

AvahiIfIndex if_index){

1024

if(debug){

1025

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

1026

}

1027

return add_delete_local_route(true, address, if_index);

1028

}

1029

1030

__attribute__((nonnull, warn_unused_result))

1031

static bool delete_local_route(const char *address,

1032

AvahiIfIndex if_index){

1033

if(debug){

1034

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

1035

}

1036

return add_delete_local_route(false, address, if_index);

1037

}

1038

631

1039

/* Called when a Mandos server is found */

1040

__attribute__((nonnull, warn_unused_result))

632

1041

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

633

1042

AvahiIfIndex if_index,

634

1043

int af, mandos_context *mc){

643

1052

int retval = -1;

644

1053

gnutls_session_t session;

645

1054

int pf; /* Protocol family */

1055

bool route_added = false;

646

1056

647

1057

errno = 0;

648

1058

670

1080

bool match = false;

671

1081

{

672

1082

char *interface = NULL;

673

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

674

interface))){

1083

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

1084

mc->interfaces_size,

1085

interface))){

675

1086

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

676

1087

match = true;

677

1088

break;

706

1117

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

707

1118

}

708

1119

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

710

1121

if(tcp_sd < 0){

711

1122

int e = errno;

712

1123

perror_plus("socket");

719

1130

goto mandos_end;

720

1131

}

721

1132

722

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

723

1133

if(af == AF_INET6){

724

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

725

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

1134

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

1135

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

1136

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

726

1137

} else { /* IPv4 */

727

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

728

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

1138

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

1139

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

1140

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

729

1141

}

730

1142

if(ret < 0 ){

731

1143

int e = errno;

740

1152

goto mandos_end;

741

1153

}

742

1154

if(af == AF_INET6){

743

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

1155

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

744

1156

if(IN6_IS_ADDR_LINKLOCAL

745

1157

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

746

1158

if(if_index == AVAHI_IF_UNSPEC){

801

1213

goto mandos_end;

802

1214

}

803

1215

804

if(af == AF_INET6){

805

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

806

sizeof(struct sockaddr_in6));

807

} else {

808

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

809

sizeof(struct sockaddr_in));

810

}

811

if(ret < 0){

812

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

813

int e = errno;

814

perror_plus("connect");

815

errno = e;

816

}

817

goto mandos_end;

818

}

819

820

if(quit_now){

821

errno = EINTR;

822

goto mandos_end;

1216

while(true){

1217

if(af == AF_INET6){

1218

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

1219

sizeof(struct sockaddr_in6));

1220

} else {

1221

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

1222

sizeof(struct sockaddr_in));

1223

}

1224

if(ret < 0){

1225

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

1226

and if_index != AVAHI_IF_UNSPEC

1227

and connect_to == NULL

1228

and not route_added and

1229

((af == AF_INET6 and not

1230

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1231

&to)->sin6_addr)))

1232

or (af == AF_INET and

1233

/* Not a a IPv4LL address */

1234

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

1235

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

1236

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

1237

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

1238

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

1239

connect to a Mandos server announced by Avahi on a server

1240

host with a global address. Work around this by retrying

1241

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

1242

1243

Avahi bug reference:

1244

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

1245

https://bugs.debian.org/587961

1246

*/

1247

if(debug){

1248

fprintf_plus(stderr, "Mandos server unreachable, trying"

1249

" direct route\n");

1250

}

1251

int e = errno;

1252

route_added = add_local_route(ip, if_index);

1253

if(route_added){

1254

continue;

1255

}

1256

errno = e;

1257

}

1258

if(errno != ECONNREFUSED or debug){

1259

int e = errno;

1260

perror_plus("connect");

1261

errno = e;

1262

}

1263

goto mandos_end;

1264

}

1265

1266

if(quit_now){

1267

errno = EINTR;

1268

goto mandos_end;

1269

}

1270

break;

823

1271

}

824

1272

825

1273

const char *out = mandos_protocol_version;

979

1427

&decrypted_buffer, mc);

980

1428

if(decrypted_buffer_size >= 0){

981

1429

1430

clearerr(stdout);

982

1431

written = 0;

983

1432

while(written < (size_t) decrypted_buffer_size){

984

1433

if(quit_now){

1000

1449

}

1001

1450

written += (size_t)ret;

1002

1451

}

1452

ret = fflush(stdout);

1453

if(ret != 0){

1454

int e = errno;

1455

if(debug){

1456

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

1457

strerror(errno));

1458

}

1459

errno = e;

1460

goto mandos_end;

1461

}

1003

1462

retval = 0;

1004

1463

}

1005

1464

}

1008

1467

1009

1468

mandos_end:

1010

1469

{

1470

if(route_added){

1471

if(not delete_local_route(ip, if_index)){

1472

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

1473

" interface %d", ip, if_index);

1474

}

1475

}

1011

1476

int e = errno;

1012

1477

free(decrypted_buffer);

1013

1478

free(buffer);

1014

1479

if(tcp_sd >= 0){

1015

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

1480

ret = close(tcp_sd);

1016

1481

}

1017

1482

if(ret == -1){

1018

1483

if(e == 0){

1043

1508

AVAHI_GCC_UNUSED AvahiStringList *txt,

1044

1509

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1045

1510

flags,

1046

void* mc){

1511

void *mc){

1047

1512

if(r == NULL){

1048

1513

return;

1049

1514

}

1052

1517

timed out */

1053

1518

1054

1519

if(quit_now){

1520

avahi_s_service_resolver_free(r);

1055

1521

return;

1056

1522

}

1057

1523

1102

1568

const char *domain,

1103

1569

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1104

1570

flags,

1105

void* mc){

1571

void *mc){

1106

1572

if(b == NULL){

1107

1573

return;

1108

1574

}

1168

1634

errno = old_errno;

1169

1635

}

1170

1636

1637

__attribute__((nonnull, warn_unused_result))

1171

1638

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

1172

1639

int ret;

1173

error_t ret_errno;

1640

int old_errno;

1174

1641

1175

1642

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

1176

1643

if(s < 0){

1177

ret_errno = errno;

1644

old_errno = errno;

1178

1645

perror_plus("socket");

1179

errno = ret_errno;

1646

errno = old_errno;

1180

1647

return false;

1181

1648

}

1182

strcpy(ifr->ifr_name, ifname);

1649

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

1650

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

1183

1651

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1184

1652

if(ret == -1){

1185

1653

if(debug){

1186

ret_errno = errno;

1654

old_errno = errno;

1187

1655

perror_plus("ioctl SIOCGIFFLAGS");

1188

errno = ret_errno;

1656

errno = old_errno;

1189

1657

}

1190

1658

return false;

1191

1659

}

1192

1660

return true;

1193

1661

}

1194

1662

1663

__attribute__((nonnull, warn_unused_result))

1195

1664

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

1196

1665

1197

1666

/* Reject the loopback device */

1239

1708

* corresponds to an acceptable network device.

1240

1709

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

1241

1710

*/

1711

__attribute__((nonnull, warn_unused_result))

1242

1712

int good_interface(const struct dirent *if_entry){

1243

1713

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

1244

1714

return 0;

1262

1732

/*

1263

1733

* This function determines if a network interface is up.

1264

1734

*/

1735

__attribute__((nonnull, warn_unused_result))

1265

1736

bool interface_is_up(const char *interface){

1266

1737

struct ifreq ifr;

1267

1738

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

1278

1749

/*

1279

1750

* This function determines if a network interface is running

1280

1751

*/

1752

__attribute__((nonnull, warn_unused_result))

1281

1753

bool interface_is_running(const char *interface){

1282

1754

struct ifreq ifr;

1283

1755

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

1291

1763

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

1292

1764

}

1293

1765

1766

__attribute__((nonnull, pure, warn_unused_result))

1294

1767

int notdotentries(const struct dirent *direntry){

1295

1768

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

1296

1769

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

1303

1776

}

1304

1777

1305

1778

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

1779

__attribute__((nonnull, warn_unused_result))

1306

1780

int runnable_hook(const struct dirent *direntry){

1307

1781

int ret;

1308

1782

size_t sret;

1316

1790

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

1317

1791

"abcdefghijklmnopqrstuvwxyz"

1318

1792

"0123456789"

1319

"_-");

1793

"_.-");

1320

1794

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

1321

1795

/* Contains non-allowed characters */

1322

1796

if(debug){

1326

1800

return 0;

1327

1801

}

1328

1802

1329

char *fullname = NULL;

1330

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

1331

if(ret < 0){

1332

perror_plus("asprintf");

1333

return 0;

1334

}

1335

1336

ret = stat(fullname, &st);

1803

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

1337

1804

if(ret == -1){

1338

1805

if(debug){

1339

1806

perror_plus("Could not stat hook");

1363

1830

return 1;

1364

1831

}

1365

1832

1833

__attribute__((nonnull, warn_unused_result))

1366

1834

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1367

1835

mandos_context *mc){

1368

1836

int ret;

1436

1904

}

1437

1905

}

1438

1906

1439

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

1440

error_t raise_privileges(void){

1441

error_t old_errno = errno;

1442

error_t ret_errno = 0;

1443

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

1444

ret_errno = errno;

1445

perror_plus("seteuid");

1446

}

1447

errno = old_errno;

1448

return ret_errno;

1449

}

1450

1451

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

1452

error_t raise_privileges_permanently(void){

1453

error_t old_errno = errno;

1454

error_t ret_errno = raise_privileges();

1455

if(ret_errno != 0){

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

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

1460

ret_errno = errno;

1461

perror_plus("seteuid");

1462

}

1463

errno = old_errno;

1464

return ret_errno;

1465

}

1466

1467

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

1468

error_t lower_privileges(void){

1469

error_t old_errno = errno;

1470

error_t ret_errno = 0;

1471

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

1472

ret_errno = errno;

1473

perror_plus("seteuid");

1474

}

1475

errno = old_errno;

1476

return ret_errno;

1477

}

1478

1479

/* Lower privileges permanently */

1480

error_t lower_privileges_permanently(void){

1481

error_t old_errno = errno;

1482

error_t ret_errno = 0;

1483

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

1484

ret_errno = errno;

1485

perror_plus("setuid");

1486

}

1487

errno = old_errno;

1488

return ret_errno;

1489

}

1490

1491

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

1907

__attribute__((nonnull))

1908

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

1492

1909

const float delay){

1493

struct dirent **direntries;

1494

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

1495

alphasort);

1910

struct dirent **direntries = NULL;

1911

if(hookdir_fd == -1){

1912

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1913

| O_CLOEXEC);

1914

if(hookdir_fd == -1){

1915

if(errno == ENOENT){

1916

if(debug){

1917

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

1918

" found\n", hookdir);

1919

}

1920

} else {

1921

perror_plus("open");

1922

}

1923

return;

1924

}

1925

}

1926

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

1927

runnable_hook, alphasort);

1496

1928

if(numhooks == -1){

1497

if(errno == ENOENT){

1498

if(debug){

1499

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

1500

" found\n", hookdir);

1501

}

1502

} else {

1503

perror_plus("scandir");

1929

perror_plus("scandir");

1930

return;

1931

}

1932

struct dirent *direntry;

1933

int ret;

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1939

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

1940

direntry = direntries[i];

1941

if(debug){

1942

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

1943

direntry->d_name);

1504

1944

}

1505

} else {

1506

struct dirent *direntry;

1507

int ret;

1508

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

1509

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

1510

direntry = direntries[i];

1511

char *fullname = NULL;

1512

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

1513

if(ret < 0){

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

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

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

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

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

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

1990

if(ret == -1){

1514

1991

perror_plus("asprintf");

1515

continue;

1516

}

1517

if(debug){

1518

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

1519

direntry->d_name);

1520

}

1521

pid_t hook_pid = fork();

1522

if(hook_pid == 0){

1523

/* Child */

1524

/* Raise privileges */

1525

raise_privileges_permanently();

1526

/* Set group */

1527

errno = 0;

1528

ret = setgid(0);

1529

if(ret == -1){

1530

perror_plus("setgid");

1531

}

1532

/* Reset supplementary groups */

1533

errno = 0;

1534

ret = setgroups(0, NULL);

1535

if(ret == -1){

1536

perror_plus("setgroups");

1537

}

1538

dup2(devnull, STDIN_FILENO);

1539

close(devnull);

1540

dup2(STDERR_FILENO, STDOUT_FILENO);

1541

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

1542

if(ret == -1){

1543

perror_plus("setenv");

1544

_exit(EX_OSERR);

1545

}

1546

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

1547

if(ret == -1){

1548

perror_plus("setenv");

1549

_exit(EX_OSERR);

1550

}

1551

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

1552

if(ret == -1){

1553

perror_plus("setenv");

1554

_exit(EX_OSERR);

1555

}

1556

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

1557

if(ret == -1){

1558

perror_plus("setenv");

1559

_exit(EX_OSERR);

1560

}

1561

char *delaystring;

1562

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

1563

if(ret == -1){

1564

perror_plus("asprintf");

1565

_exit(EX_OSERR);

1566

}

1567

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

1568

if(ret == -1){

1569

free(delaystring);

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1573

1996

free(delaystring);

1574

if(connect_to != NULL){

1575

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

1576

if(ret == -1){

1577

perror_plus("setenv");

1578

_exit(EX_OSERR);

1579

}

1580

}

1581

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

1582

perror_plus("execl");

1583

_exit(EXIT_FAILURE);

1584

}

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

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

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

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

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

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

2054

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

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

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

2061

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

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

1585

2065

} else {

1586

int status;

1587

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

1588

perror_plus("waitpid");

1589

free(fullname);

1590

continue;

1591

}

1592

if(WIFEXITED(status)){

1593

if(WEXITSTATUS(status) != 0){

1594

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

1595

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

1596

WEXITSTATUS(status));

1597

free(fullname);

1598

continue;

1599

}

1600

} else if(WIFSIGNALED(status)){

1601

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

1602

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

1603

WTERMSIG(status));

1604

free(fullname);

1605

continue;

1606

} else {

1607

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

1608

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

1609

free(fullname);

1610

continue;

1611

}

1612

}

1613

free(fullname);

1614

if(debug){

1615

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

1616

direntry->d_name);

1617

}

1618

}

1619

close(devnull);

1620

}

1621

return true;

2066

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

2067

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

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

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

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

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

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

1622

2085

}

1623

2086

1624

error_t bring_up_interface(const char *const interface,

1625

const float delay){

1626

int sd = -1;

1627

error_t old_errno = errno;

1628

error_t ret_errno = 0;

1629

int ret, ret_setflags;

2087

__attribute__((nonnull, warn_unused_result))

2088

int bring_up_interface(const char *const interface,

2089

const float delay){

2090

int old_errno = errno;

2091

int ret;

1630

2092

struct ifreq network;

1631

2093

unsigned int if_index = if_nametoindex(interface);

1632

2094

if(if_index == 0){

1641

2103

}

1642

2104

1643

2105

if(not interface_is_up(interface)){

1644

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

2106

int ret_errno = 0;

2107

int ioctl_errno = 0;

2108

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

1645

2109

ret_errno = errno;

1646

2110

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

1647

2111

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

2112

errno = old_errno;

1648

2113

return ret_errno;

1649

2114

}

1650

network.ifr_flags |= IFF_UP;

2115

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

1651

2116

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

2117

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

2118

if(sd == -1){

1654

2119

ret_errno = errno;

1655

2120

perror_plus("socket");

1656

2121

errno = old_errno;

1657

2122

return ret_errno;

1658

2123

}

1659

2124

1660

2125

if(quit_now){

1661

close(sd);

2126

ret = close(sd);

2127

if(ret == -1){

2128

perror_plus("close");

2129

}

1662

2130

errno = old_errno;

1663

2131

return EINTR;

1664

2132

}

1668

2136

interface);

1669

2137

}

1670

2138

1671

/* Raise priviliges */

1672

raise_privileges();

2139

/* Raise privileges */

2140

ret_errno = raise_privileges();

2141

if(ret_errno != 0){

2142

errno = ret_errno;

2143

perror_plus("Failed to raise privileges");

2144

}

1673

2145

1674

2146

#ifdef __linux__

1675

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1676

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

1677

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

1678

bool restore_loglevel = true;

1679

if(ret_linux == -1){

1680

restore_loglevel = false;

1681

perror_plus("klogctl");

2147

int ret_linux;

2148

bool restore_loglevel = false;

2149

if(ret_errno == 0){

2150

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2151

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

2152

ret_linux = klogctl(8, NULL, 5);

2153

if(ret_linux == -1){

2154

perror_plus("klogctl");

2155

} else {

2156

restore_loglevel = true;

2157

}

1682

2158

}

1683

2159

#endif /* __linux__ */

1684

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

1685

ret_errno = errno;

2160

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

2161

ioctl_errno = errno;

1686

2162

#ifdef __linux__

1687

2163

if(restore_loglevel){

1688

2164

ret_linux = klogctl(7, NULL, 0);

1692

2168

}

1693

2169

#endif /* __linux__ */

1694

2170

1695

/* Lower privileges */

1696

lower_privileges();

2171

/* If raise_privileges() succeeded above */

2172

if(ret_errno == 0){

2173

/* Lower privileges */

2174

ret_errno = lower_privileges();

2175

if(ret_errno != 0){

2176

errno = ret_errno;

2177

perror_plus("Failed to lower privileges");

2178

}

2179

}

1697

2180

1698

2181

/* Close the socket */

1699

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

2182

ret = close(sd);

1700

2183

if(ret == -1){

1701

2184

perror_plus("close");

1702

2185

}

1703

2186

1704

2187

if(ret_setflags == -1){

1705

errno = ret_errno;

2188

errno = ioctl_errno;

1706

2189

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1707

2190

errno = old_errno;

1708

return ret_errno;

2191

return ioctl_errno;

1709

2192

}

1710

2193

} else if(debug){

1711

2194

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

1714

2197

1715

2198

/* Sleep checking until interface is running.

1716

2199

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

1717

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

2200

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

1718

2201

if(interface_is_running(interface)){

1719

2202

break;

1720

2203

}

1729

2212

return 0;

1730

2213

}

1731

2214

1732

error_t take_down_interface(const char *const interface){

1733

error_t old_errno = errno;

2215

__attribute__((nonnull, warn_unused_result))

2216

int take_down_interface(const char *const interface){

2217

int old_errno = errno;

1734

2218

struct ifreq network;

1735

2219

unsigned int if_index = if_nametoindex(interface);

1736

2220

if(if_index == 0){

1739

2223

return ENXIO;

1740

2224

}

1741

2225

if(interface_is_up(interface)){

1742

error_t ret_errno = 0;

2226

int ret_errno = 0;

2227

int ioctl_errno = 0;

1743

2228

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

1744

2229

ret_errno = errno;

1745

2230

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

1746

2231

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

2232

errno = old_errno;

1747

2233

return ret_errno;

1748

2234

}

1749

2235

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

1750

2236

1751

2237

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

1752

if(sd < 0){

2238

if(sd == -1){

1753

2239

ret_errno = errno;

1754

2240

perror_plus("socket");

1755

2241

errno = old_errno;

1761

2247

interface);

1762

2248

}

1763

2249

1764

/* Raise priviliges */

1765

raise_privileges();

2250

/* Raise privileges */

2251

ret_errno = raise_privileges();

2252

if(ret_errno != 0){

2253

errno = ret_errno;

2254

perror_plus("Failed to raise privileges");

2255

}

1766

2256

1767

2257

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

1768

ret_errno = errno;

2258

ioctl_errno = errno;

1769

2259

1770

/* Lower privileges */

1771

lower_privileges();

2260

/* If raise_privileges() succeeded above */

2261

if(ret_errno == 0){

2262

/* Lower privileges */

2263

ret_errno = lower_privileges();

2264

if(ret_errno != 0){

2265

errno = ret_errno;

2266

perror_plus("Failed to lower privileges");

2267

}

2268

}

1772

2269

1773

2270

/* Close the socket */

1774

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

2271

int ret = close(sd);

1775

2272

if(ret == -1){

1776

2273

perror_plus("close");

1777

2274

}

1778

2275

1779

2276

if(ret_setflags == -1){

1780

errno = ret_errno;

2277

errno = ioctl_errno;

1781

2278

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1782

2279

errno = old_errno;

1783

return ret_errno;

2280

return ioctl_errno;

1784

2281

}

1785

2282

} else if(debug){

1786

2283

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

1792

2289

}

1793

2290

1794

2291

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

1795

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

1796

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

1797

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

1798

.interfaces = NULL, .interfaces_size = 0 };

2292

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

2293

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

2294

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

2295

.current_server = NULL, .interfaces = NULL,

2296

.interfaces_size = 0 };

1799

2297

AvahiSServiceBrowser *sb = NULL;

1800

2298

error_t ret_errno;

1801

2299

int ret;

1804

2302

int exitcode = EXIT_SUCCESS;

1805

2303

char *interfaces_to_take_down = NULL;

1806

2304

size_t interfaces_to_take_down_size = 0;

1807

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

1808

bool tempdir_created = false;

2305

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

2306

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

2307

char *tempdir = NULL;

1809

2308

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1810

2309

const char *seckey = PATHDIR "/" SECKEY;

1811

2310

const char *pubkey = PATHDIR "/" PUBKEY;

2311

const char *dh_params_file = NULL;

1812

2312

char *interfaces_hooks = NULL;

1813

2313

1814

2314

bool gnutls_initialized = false;

1867

2367

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

1868

2368

" Diffie-Hellman key exchange",

1869

2369

.group = 2 },

2370

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

2371

.arg = "FILE",

2372

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

2373

" for the Diffie-Hellman key exchange",

2374

.group = 2 },

1870

2375

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

1871

2376

.arg = "STRING",

1872

2377

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

1927

2432

}

1928

2433

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

1929

2434

break;

2435

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

2436

dh_params_file = arg;

2437

break;

1930

2438

case 130: /* --priority */

1931

2439

mc.priority = arg;

1932

2440

break;

1972

2480

.args_doc = "",

1973

2481

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

1974

2482

" passwords from a Mandos server" };

1975

ret = argp_parse(&argp, argc, argv,

1976

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1977

switch(ret){

2483

ret_errno = argp_parse(&argp, argc, argv,

2484

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2485

switch(ret_errno){

1978

2486

case 0:

1979

2487

break;

1980

2488

case ENOMEM:

1981

2489

default:

1982

errno = ret;

2490

errno = ret_errno;

1983

2491

perror_plus("argp_parse");

1984

2492

exitcode = EX_OSERR;

1985

2493

goto end;

1988

2496

goto end;

1989

2497

}

1990

2498

}

1991

2499

1992

2500

{

1993

2501

/* Work around Debian bug #633582:

1994

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

2502

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

1995

2503

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2504

/* Re-raise privileges */

2505

ret = raise_privileges();

2506

if(ret != 0){

2507

errno = ret;

2508

perror_plus("Failed to raise privileges");

2509

} else {

1998

2510

struct stat st;

1999

2511

2000

2512

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

2014

2526

}

2015

2527

}

2016

2528

}

2017

TEMP_FAILURE_RETRY(close(seckey_fd));

2529

close(seckey_fd);

2018

2530

}

2019

2531

}

2020

2532

2021

2533

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

2022

2534

int pubkey_fd = open(pubkey, O_RDONLY);

2023

2535

if(pubkey_fd == -1){

2035

2547

}

2036

2548

}

2037

2549

}

2038

TEMP_FAILURE_RETRY(close(pubkey_fd));

2039

}

2040

}

2041

2550

close(pubkey_fd);

2551

}

2552

}

2553

2554

if(dh_params_file != NULL

2555

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

2556

int dhparams_fd = open(dh_params_file, O_RDONLY);

2557

if(dhparams_fd == -1){

2558

perror_plus("open");

2559

} else {

2560

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

2561

if(ret == -1){

2562

perror_plus("fstat");

2563

} else {

2564

if(S_ISREG(st.st_mode)

2565

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

2566

ret = fchown(dhparams_fd, uid, gid);

2567

if(ret == -1){

2568

perror_plus("fchown");

2569

}

2570

}

2571

}

2572

close(dhparams_fd);

2573

}

2574

}

2575

2042

2576

/* Lower privileges */

2043

lower_privileges();

2577

ret = lower_privileges();

2578

if(ret != 0){

2579

errno = ret;

2580

perror_plus("Failed to lower privileges");

2581

}

2044

2582

}

2045

2583

}

2046

2584

2072

2610

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

2073

2611

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

2074

2612

}

2075

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

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2613

run_network_hooks("start", interfaces_hooks != NULL ?

2614

interfaces_hooks : "", delay);

2079

2615

}

2080

2616

2081

2617

if(not debug){

2159

2695

2160

2696

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

2161

2697

if(mc.interfaces == NULL){

2162

struct dirent **direntries;

2698

struct dirent **direntries = NULL;

2163

2699

/* Look for any good interfaces */

2164

2700

ret = scandir(sys_class_net, &direntries, good_interface,

2165

2701

alphasort);

2171

2707

if(ret_errno != 0){

2172

2708

errno = ret_errno;

2173

2709

perror_plus("argz_add");

2710

free(direntries[i]);

2174

2711

continue;

2175

2712

}

2176

2713

if(debug){

2177

2714

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

2178

2715

direntries[i]->d_name);

2179

2716

}

2717

free(direntries[i]);

2180

2718

}

2181

2719

free(direntries);

2182

2720

} else {

2183

free(direntries);

2721

if(ret == 0){

2722

free(direntries);

2723

}

2184

2724

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

2185

2725

exitcode = EXIT_FAILURE;

2186

2726

goto end;

2209

2749

break;

2210

2750

}

2211

2751

bool interface_was_up = interface_is_up(interface);

2212

ret = bring_up_interface(interface, delay);

2752

errno = bring_up_interface(interface, delay);

2213

2753

if(not interface_was_up){

2214

if(ret != 0){

2215

errno = ret;

2216

perror_plus("Failed to bring up interface");

2754

if(errno != 0){

2755

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

2756

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

2217

2757

} else {

2218

ret_errno = argz_add(&interfaces_to_take_down,

2219

&interfaces_to_take_down_size,

2220

interface);

2221

if(ret_errno != 0){

2222

errno = ret_errno;

2758

errno = argz_add(&interfaces_to_take_down,

2759

&interfaces_to_take_down_size,

2760

interface);

2761

if(errno != 0){

2223

2762

perror_plus("argz_add");

2224

2763

}

2225

2764

}

2243

2782

goto end;

2244

2783

}

2245

2784

2246

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

2785

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

2247

2786

if(ret == -1){

2248

2787

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

2249

2788

exitcode = EX_UNAVAILABLE;

2256

2795

goto end;

2257

2796

}

2258

2797

2259

if(mkdtemp(tempdir) == NULL){

2798

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

2799

tempdir = mkdtemp(run_tempdir);

2800

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

2801

if(debug){

2802

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

2803

run_tempdir, old_tempdir);

2804

}

2805

tempdir = mkdtemp(old_tempdir);

2806

}

2807

if(tempdir == NULL){

2260

2808

perror_plus("mkdtemp");

2261

2809

goto end;

2262

2810

}

2263

tempdir_created = true;

2264

2811

2265

2812

if(quit_now){

2266

2813

goto end;

2363

2910

2364

2911

/* Allocate a new server */

2365

2912

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2366

&config, NULL, NULL, &ret_errno);

2913

&config, NULL, NULL, &ret);

2367

2914

2368

2915

/* Free the Avahi configuration data */

2369

2916

avahi_server_config_free(&config);

2372

2919

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

2373

2920

if(mc.server == NULL){

2374

2921

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

2375

avahi_strerror(ret_errno));

2922

avahi_strerror(ret));

2376

2923

exitcode = EX_UNAVAILABLE;

2377

2924

goto end;

2378

2925

}

2402

2949

if(debug){

2403

2950

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

2404

2951

}

2405

2952

2406

2953

ret = avahi_loop_with_timeout(simple_poll,

2407

2954

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

2408

2955

if(debug){

2413

2960

end:

2414

2961

2415

2962

if(debug){

2416

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

2963

if(signal_received){

2964

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

2965

argv[0], signal_received,

2966

strsignal(signal_received));

2967

} else {

2968

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

2969

}

2417

2970

}

2418

2971

2419

2972

/* Cleanup things */

2430

2983

2431

2984

if(gnutls_initialized){

2432

2985

gnutls_certificate_free_credentials(mc.cred);

2433

gnutls_global_deinit();

2434

2986

gnutls_dh_params_deinit(mc.dh_params);

2435

2987

}

2436

2988

2444

2996

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

2445

2997

while(mc.current_server != NULL){

2446

2998

server *next = mc.current_server->next;

2999

#ifdef __GNUC__

3000

#pragma GCC diagnostic push

3001

#pragma GCC diagnostic ignored "-Wcast-qual"

3002

#endif

3003

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

3004

#ifdef __GNUC__

3005

#pragma GCC diagnostic pop

3006

#endif

2447

3007

free(mc.current_server);

2448

3008

mc.current_server = next;

2449

3009

}

2450

3010

}

2451

3011

2452

/* Re-raise priviliges */

3012

/* Re-raise privileges */

2453

3013

{

2454

raise_privileges();

2455

2456

/* Run network hooks */

2457

run_network_hooks("stop", interfaces_hooks != NULL ?

2458

interfaces_hooks : "", delay);

2459

2460

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

2461

{

2462

char *interface = NULL;

2463

while((interface=argz_next(interfaces_to_take_down,

2464

interfaces_to_take_down_size,

2465

interface))){

2466

ret_errno = take_down_interface(interface);

2467

if(ret_errno != 0){

2468

errno = ret_errno;

2469

perror_plus("Failed to take down interface");

2470

}

2471

}

2472

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

2473

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

2474

" down\n");

2475

}

2476

}

2477

2478

lower_privileges_permanently();

3014

ret = raise_privileges();

3015

if(ret != 0){

3016

errno = ret;

3017

perror_plus("Failed to raise privileges");

3018

} else {

3019

3020

/* Run network hooks */

3021

run_network_hooks("stop", interfaces_hooks != NULL ?

3022

interfaces_hooks : "", delay);

3023

3024

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

3025

{

3026

char *interface = NULL;

3027

while((interface = argz_next(interfaces_to_take_down,

3028

interfaces_to_take_down_size,

3029

interface))){

3030

ret = take_down_interface(interface);

3031

if(ret != 0){

3032

errno = ret;

3033

perror_plus("Failed to take down interface");

3034

}

3035

}

3036

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

3037

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

3038

" down\n");

3039

}

3040

}

3041

}

3042

3043

ret = lower_privileges_permanently();

3044

if(ret != 0){

3045

errno = ret;

3046

perror_plus("Failed to lower privileges permanently");

3047

}

2479

3048

}

2480

3049

2481

3050

free(interfaces_to_take_down);

2482

3051

free(interfaces_hooks);

2483

3052

3053

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

3054

uintmax_t level){

3055

struct dirent **direntries = NULL;

3056

int dret;

3057

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

3058

O_RDONLY

3059

| O_NOFOLLOW

3060

| O_DIRECTORY

3061

| O_PATH));

3062

if(dir_fd == -1){

3063

perror_plus("open");

3064

}

3065

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

3066

notdotentries, alphasort);

3067

if(numentries >= 0){

3068

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

3069

if(debug){

3070

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

3071

dirname, direntries[i]->d_name);

3072

}

3073

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

3074

if(dret == -1){

3075

if(errno == EISDIR){

3076

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

3077

AT_REMOVEDIR);

3078

}

3079

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

3080

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

3081

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

3082

/* Recurse only in this special case */

3083

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

3084

dret = 0;

3085

}

3086

if(dret == -1){

3087

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

3088

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

3089

}

3090

}

3091

free(direntries[i]);

3092

}

3093

3094

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

3095

free(direntries);

3096

if(numentries == -1){

3097

perror_plus("scandirat");

3098

}

3099

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3100

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

3101

perror_plus("rmdir");

3102

}

3103

} else {

3104

perror_plus("scandirat");

3105

}

3106

close(dir_fd);

3107

}

3108

2484

3109

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

2485

if(tempdir_created){

2486

struct dirent **direntries = NULL;

2487

struct dirent *direntry = NULL;

2488

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

2489

alphasort);

2490

if(numentries > 0){

2491

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

2492

direntry = direntries[i];

2493

char *fullname = NULL;

2494

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

2495

direntry->d_name);

2496

if(ret < 0){

2497

perror_plus("asprintf");

2498

continue;

2499

}

2500

ret = remove(fullname);

2501

if(ret == -1){

2502

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

2503

strerror(errno));

2504

}

2505

free(fullname);

2506

}

2507

}

2508

2509

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

2510

free(direntries);

2511

if(numentries == -1){

2512

perror_plus("scandir");

2513

}

2514

ret = rmdir(tempdir);

2515

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

2516

perror_plus("rmdir");

2517

}

3110

if(tempdir != NULL){

3111

clean_dir_at(-1, tempdir, 0);

2518

3112

}

2519

3113

2520

3114

if(quit_now){