/mandos/trunk : revision 237.4.81

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

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

43

stdout, ferror() */

44

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

45

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

46

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

47

strtof(), abort() */

48

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

49

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

50

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

49

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

50

asprintf(), strncpy(), strsignal()

51

*/

51

52

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

52

53

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

53

54

sockaddr_in6, PF_INET6,

57

58

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

58

59

inet_pton(), connect(),

59

60

getnameinfo() */

60

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

61

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

61

62

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

62

63

*/

63

64

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

64

65

strtoimax() */

65

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

66

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

67

EAI_SYSTEM, ENETUNREACH,

68

EHOSTUNREACH, ECONNREFUSED, EPROTO,

69

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

70

ENOTEMPTY,

66

71

program_invocation_short_name */

67

72

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

68

73

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

73

78

*/

74

79

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

75

80

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

76

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

81

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

82

unlinkat() */

77

83

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

78

84

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

79

85

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

141

147

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

142

148

char *connect_to = NULL;

143

149

const char *hookdir = HOOKDIR;

150

int hookdir_fd = -1;

144

151

uid_t uid = 65534;

145

152

gid_t gid = 65534;

146

153

183

190

perror(print_text);

184

191

}

185

192

186

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

193

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

187

194

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

188

195

va_list ap;

189

196

va_start (ap, format);

198

205

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

199

206

* "buffer_length" is how much is already used.

200

207

*/

208

__attribute__((nonnull, warn_unused_result))

201

209

size_t incbuffer(char **buffer, size_t buffer_length,

202

210

size_t buffer_capacity){

203

211

if(buffer_length + BUFFER_SIZE > buffer_capacity){

216

224

}

217

225

218

226

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

227

__attribute__((nonnull, warn_unused_result))

219

228

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

220

229

int af, server **current_server){

221

230

int ret;

230

239

.af = af };

231

240

if(new_server->ip == NULL){

232

241

perror_plus("strdup");

242

free(new_server);

233

243

return false;

234

244

}

235

245

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

236

246

if(ret == -1){

237

247

perror_plus("clock_gettime");

248

#ifdef __GNUC__

249

#pragma GCC diagnostic push

250

#pragma GCC diagnostic ignored "-Wcast-qual"

251

#endif

252

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

253

#ifdef __GNUC__

254

#pragma GCC diagnostic pop

255

#endif

256

free(new_server);

238

257

return false;

239

258

}

240

259

/* Special case of first server */

242

261

new_server->next = new_server;

243

262

new_server->prev = new_server;

244

263

*current_server = new_server;

245

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

246

264

} else {

265

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

247

266

new_server->next = *current_server;

248

267

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

249

268

new_server->prev->next = new_server;

255

274

/*

256

275

* Initialize GPGME.

257

276

*/

258

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

259

const char *tempdir, mandos_context *mc){

277

__attribute__((nonnull, warn_unused_result))

278

static bool init_gpgme(const char * const seckey,

279

const char * const pubkey,

280

const char * const tempdir,

281

mandos_context *mc){

260

282

gpgme_error_t rc;

261

283

gpgme_engine_info_t engine_info;

262

284

263

285

/*

264

286

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

265

287

*/

266

bool import_key(const char *filename){

288

bool import_key(const char * const filename){

267

289

int ret;

268

290

int fd;

269

291

gpgme_data_t pgp_data;

288

310

return false;

289

311

}

290

312

291

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

313

ret = close(fd);

292

314

if(ret == -1){

293

315

perror_plus("close");

294

316

}

350

372

* Decrypt OpenPGP data.

351

373

* Returns -1 on error

352

374

*/

375

__attribute__((nonnull, warn_unused_result))

353

376

static ssize_t pgp_packet_decrypt(const char *cryptotext,

354

377

size_t crypto_size,

355

378

char **plaintext,

475

498

return plaintext_length;

476

499

}

477

500

478

static const char * safer_gnutls_strerror(int value){

501

__attribute__((warn_unused_result, const))

502

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

503

if(str == NULL)

504

return "(unknown)";

505

return str;

506

}

507

508

__attribute__((warn_unused_result))

509

static const char *safer_gnutls_strerror(int value){

479

510

const char *ret = gnutls_strerror(value);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

511

return safe_string(ret);

483

512

}

484

513

485

514

/* GnuTLS log function callback */

515

__attribute__((nonnull))

486

516

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

487

517

const char* string){

488

518

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

489

519

}

490

520

521

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

491

522

static int init_gnutls_global(const char *pubkeyfilename,

492

523

const char *seckeyfilename,

524

const char *dhparamsfilename,

493

525

mandos_context *mc){

494

526

int ret;

527

unsigned int uret;

495

528

496

529

if(debug){

497

530

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

498

531

}

499

532

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

533

if(debug){

508

534

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

509

535

* - GnuTLS manual

517

543

if(ret != GNUTLS_E_SUCCESS){

518

544

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

519

545

safer_gnutls_strerror(ret));

520

gnutls_global_deinit();

521

546

return -1;

522

547

}

523

548

573

safer_gnutls_strerror(ret));

549

574

goto globalfail;

550

575

}

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

576

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

577

if(dhparamsfilename != NULL){

578

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

579

do {

580

int dhpfile = open(dhparamsfilename, O_RDONLY);

581

if(dhpfile == -1){

582

perror_plus("open");

583

dhparamsfilename = NULL;

584

break;

585

}

586

size_t params_capacity = 0;

587

while(true){

588

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

589

(size_t)params.size,

590

(size_t)params_capacity);

591

if(params_capacity == 0){

592

perror_plus("incbuffer");

593

free(params.data);

594

params.data = NULL;

595

dhparamsfilename = NULL;

596

break;

597

}

598

ssize_t bytes_read = read(dhpfile,

599

params.data + params.size,

600

BUFFER_SIZE);

601

/* EOF */

602

if(bytes_read == 0){

603

break;

604

}

605

/* check bytes_read for failure */

606

if(bytes_read < 0){

607

perror_plus("read");

608

free(params.data);

609

params.data = NULL;

610

dhparamsfilename = NULL;

611

break;

612

}

613

params.size += (unsigned int)bytes_read;

614

}

615

if(params.data == NULL){

616

dhparamsfilename = NULL;

617

}

618

if(dhparamsfilename == NULL){

619

break;

620

}

621

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

622

GNUTLS_X509_FMT_PEM);

623

if(ret != GNUTLS_E_SUCCESS){

624

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

625

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

626

safer_gnutls_strerror(ret));

627

dhparamsfilename = NULL;

628

}

629

} while(false);

630

}

631

if(dhparamsfilename == NULL){

632

if(mc->dh_bits == 0){

633

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

634

/* Try to read the private key file */

635

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

636

do {

637

int secfile = open(seckeyfilename, O_RDONLY);

638

if(secfile == -1){

639

perror_plus("open");

640

break;

641

}

642

size_t buffer_capacity = 0;

643

while(true){

644

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

645

(size_t)buffer.size,

646

(size_t)buffer_capacity);

647

if(buffer_capacity == 0){

648

perror_plus("incbuffer");

649

free(buffer.data);

650

buffer.data = NULL;

651

break;

652

}

653

ssize_t bytes_read = read(secfile,

654

buffer.data + buffer.size,

655

BUFFER_SIZE);

656

/* EOF */

657

if(bytes_read == 0){

658

break;

659

}

660

/* check bytes_read for failure */

661

if(bytes_read < 0){

662

perror_plus("read");

663

free(buffer.data);

664

buffer.data = NULL;

665

break;

666

}

667

buffer.size += (unsigned int)bytes_read;

668

}

669

close(secfile);

670

} while(false);

671

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

672

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

673

if(buffer.data != NULL){

674

{

675

gnutls_openpgp_privkey_t privkey = NULL;

676

ret = gnutls_openpgp_privkey_init(&privkey);

677

if(ret != GNUTLS_E_SUCCESS){

678

fprintf_plus(stderr, "Error initializing OpenPGP key"

679

" structure: %s",

680

safer_gnutls_strerror(ret));

681

free(buffer.data);

682

buffer.data = NULL;

683

} else {

684

ret = gnutls_openpgp_privkey_import

685

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

686

if(ret != GNUTLS_E_SUCCESS){

687

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

688

safer_gnutls_strerror(ret));

689

privkey = NULL;

690

}

691

free(buffer.data);

692

buffer.data = NULL;

693

if(privkey != NULL){

694

/* Use private key to suggest an appropriate

695

sec_param */

696

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

697

gnutls_openpgp_privkey_deinit(privkey);

698

if(debug){

699

fprintf_plus(stderr, "This OpenPGP key implies using"

700

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

701

safe_string(gnutls_sec_param_get_name

702

(sec_param)));

703

}

704

}

705

}

706

}

707

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

708

/* Err on the side of caution */

709

sec_param = GNUTLS_SEC_PARAM_ULTRA;

710

if(debug){

711

fprintf_plus(stderr, "Falling back to security parameter"

712

" \"%s\"\n",

713

safe_string(gnutls_sec_param_get_name

714

(sec_param)));

715

}

716

}

717

}

718

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

719

if(uret != 0){

720

mc->dh_bits = uret;

721

if(debug){

722

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

723

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

724

safe_string(gnutls_sec_param_get_name

725

(sec_param)),

726

mc->dh_bits);

727

}

728

} else {

729

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

730

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

731

safe_string(gnutls_sec_param_get_name

732

(sec_param)),

733

safer_gnutls_strerror(ret));

734

goto globalfail;

735

}

736

} else if(debug){

737

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

738

mc->dh_bits);

739

}

740

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

741

if(ret != GNUTLS_E_SUCCESS){

742

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

743

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

744

safer_gnutls_strerror(ret));

745

goto globalfail;

746

}

747

}

558

748

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

559

749

560

750

return 0;

562

752

globalfail:

563

753

564

754

gnutls_certificate_free_credentials(mc->cred);

565

gnutls_global_deinit();

566

755

gnutls_dh_params_deinit(mc->dh_params);

567

756

return -1;

568

757

}

569

758

759

__attribute__((nonnull, warn_unused_result))

570

760

static int init_gnutls_session(gnutls_session_t *session,

571

761

mandos_context *mc){

572

762

int ret;

619

809

/* ignore client certificate if any. */

620

810

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

621

811

622

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

623

624

812

return 0;

625

813

}

626

814

628

816

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

629

817

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

630

818

819

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

820

__attribute__((warn_unused_result))

821

int raise_privileges(void){

822

int old_errno = errno;

823

int ret = 0;

824

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

825

ret = errno;

826

}

827

errno = old_errno;

828

return ret;

829

}

830

831

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

832

__attribute__((warn_unused_result))

833

int raise_privileges_permanently(void){

834

int old_errno = errno;

835

int ret = raise_privileges();

836

if(ret != 0){

837

errno = old_errno;

838

return ret;

839

}

840

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

841

ret = errno;

842

}

843

errno = old_errno;

844

return ret;

845

}

846

847

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

848

__attribute__((warn_unused_result))

849

int lower_privileges(void){

850

int old_errno = errno;

851

int ret = 0;

852

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

853

ret = errno;

854

}

855

errno = old_errno;

856

return ret;

857

}

858

859

/* Lower privileges permanently */

860

__attribute__((warn_unused_result))

861

int lower_privileges_permanently(void){

862

int old_errno = errno;

863

int ret = 0;

864

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

865

ret = errno;

866

}

867

errno = old_errno;

868

return ret;

869

}

870

871

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

872

__attribute__((nonnull, warn_unused_result))

873

static bool add_delete_local_route(const bool add,

874

const char *address,

875

AvahiIfIndex if_index){

876

int ret;

877

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

878

char add_arg[] = "add";

879

char delete_arg[] = "delete";

880

char debug_flag[] = "--debug";

881

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

882

if(pluginhelperdir == NULL){

883

if(debug){

884

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

885

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

886

}

887

return false;

888

}

889

890

char interface[IF_NAMESIZE];

891

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

892

perror_plus("if_indextoname");

893

return false;

894

}

895

896

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

897

if(devnull == -1){

898

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

899

return false;

900

}

901

pid_t pid = fork();

902

if(pid == 0){

903

/* Child */

904

/* Raise privileges */

905

errno = raise_privileges_permanently();

906

if(errno != 0){

907

perror_plus("Failed to raise privileges");

908

/* _exit(EX_NOPERM); */

909

} else {

910

/* Set group */

911

errno = 0;

912

ret = setgid(0);

913

if(ret == -1){

914

perror_plus("setgid");

915

_exit(EX_NOPERM);

916

}

917

/* Reset supplementary groups */

918

errno = 0;

919

ret = setgroups(0, NULL);

920

if(ret == -1){

921

perror_plus("setgroups");

922

_exit(EX_NOPERM);

923

}

924

}

925

ret = dup2(devnull, STDIN_FILENO);

926

if(ret == -1){

927

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

928

_exit(EX_OSERR);

929

}

930

ret = close(devnull);

931

if(ret == -1){

932

perror_plus("close");

933

_exit(EX_OSERR);

934

}

935

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

936

if(ret == -1){

937

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

938

_exit(EX_OSERR);

939

}

940

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

941

O_RDONLY

942

| O_DIRECTORY

943

| O_PATH

944

| O_CLOEXEC));

945

if(helperdir_fd == -1){

946

perror_plus("open");

947

_exit(EX_UNAVAILABLE);

948

}

949

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

950

helper, O_RDONLY));

951

if(helper_fd == -1){

952

perror_plus("openat");

953

close(helperdir_fd);

954

_exit(EX_UNAVAILABLE);

955

}

956

close(helperdir_fd);

957

#ifdef __GNUC__

958

#pragma GCC diagnostic push

959

#pragma GCC diagnostic ignored "-Wcast-qual"

960

#endif

961

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

962

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

963

interface, debug ? debug_flag : NULL, NULL },

964

environ) == -1){

965

#ifdef __GNUC__

966

#pragma GCC diagnostic pop

967

#endif

968

perror_plus("fexecve");

969

_exit(EXIT_FAILURE);

970

}

971

}

972

if(pid == -1){

973

perror_plus("fork");

974

return false;

975

}

976

int status;

977

pid_t pret = -1;

978

errno = 0;

979

do {

980

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

981

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

982

int errno_raising = 0;

983

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

984

errno_raising = errno;

985

perror_plus("Failed to raise privileges in order to"

986

" kill helper program");

987

}

988

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

989

perror_plus("kill");

990

}

991

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

992

perror_plus("Failed to lower privileges after killing"

993

" helper program");

994

}

995

return false;

996

}

997

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

998

if(pret == -1){

999

perror_plus("waitpid");

1000

return false;

1001

}

1002

if(WIFEXITED(status)){

1003

if(WEXITSTATUS(status) != 0){

1004

fprintf_plus(stderr, "Error: iprouteadddel exited"

1005

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

1006

return false;

1007

}

1008

return true;

1009

}

1010

if(WIFSIGNALED(status)){

1011

fprintf_plus(stderr, "Error: iprouteadddel died by"

1012

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

1013

return false;

1014

}

1015

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

1016

return false;

1017

}

1018

1019

__attribute__((nonnull, warn_unused_result))

1020

static bool add_local_route(const char *address,

1021

AvahiIfIndex if_index){

1022

if(debug){

1023

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

1024

}

1025

return add_delete_local_route(true, address, if_index);

1026

}

1027

1028

__attribute__((nonnull, warn_unused_result))

1029

static bool delete_local_route(const char *address,

1030

AvahiIfIndex if_index){

1031

if(debug){

1032

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

1033

}

1034

return add_delete_local_route(false, address, if_index);

1035

}

1036

631

1037

/* Called when a Mandos server is found */

1038

__attribute__((nonnull, warn_unused_result))

632

1039

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

633

1040

AvahiIfIndex if_index,

634

1041

int af, mandos_context *mc){

643

1050

int retval = -1;

644

1051

gnutls_session_t session;

645

1052

int pf; /* Protocol family */

1053

bool route_added = false;

646

1054

647

1055

errno = 0;

648

1056

706

1114

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

707

1115

}

708

1116

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

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

710

1118

if(tcp_sd < 0){

711

1119

int e = errno;

712

1120

perror_plus("socket");

719

1127

goto mandos_end;

720

1128

}

721

1129

722

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

723

1130

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);

1131

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

1132

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

1133

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

726

1134

} 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);

1135

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

1136

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

1137

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

729

1138

}

730

1139

if(ret < 0 ){

731

1140

int e = errno;

740

1149

goto mandos_end;

741

1150

}

742

1151

if(af == AF_INET6){

743

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

1152

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

744

1153

if(IN6_IS_ADDR_LINKLOCAL

745

1154

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

746

1155

if(if_index == AVAHI_IF_UNSPEC){

801

1210

goto mandos_end;

802

1211

}

803

1212

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;

1213

while(true){

1214

if(af == AF_INET6){

1215

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

1216

sizeof(struct sockaddr_in6));

1217

} else {

1218

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

1219

sizeof(struct sockaddr_in));

1220

}

1221

if(ret < 0){

1222

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

1223

and if_index != AVAHI_IF_UNSPEC

1224

and connect_to == NULL

1225

and not route_added and

1226

((af == AF_INET6 and not

1227

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1228

&to)->sin6_addr)))

1229

or (af == AF_INET and

1230

/* Not a a IPv4LL address */

1231

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

1232

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

1233

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

1234

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

1235

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

1236

connect to a Mandos server announced by Avahi on a server

1237

host with a global address. Work around this by retrying

1238

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

1239

1240

Avahi bug reference:

1241

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

1242

https://bugs.debian.org/587961

1243

*/

1244

if(debug){

1245

fprintf_plus(stderr, "Mandos server unreachable, trying"

1246

" direct route\n");

1247

}

1248

int e = errno;

1249

route_added = add_local_route(ip, if_index);

1250

if(route_added){

1251

continue;

1252

}

1253

errno = e;

1254

}

1255

if(errno != ECONNREFUSED or debug){

1256

int e = errno;

1257

perror_plus("connect");

1258

errno = e;

1259

}

1260

goto mandos_end;

1261

}

1262

1263

if(quit_now){

1264

errno = EINTR;

1265

goto mandos_end;

1266

}

1267

break;

823

1268

}

824

1269

825

1270

const char *out = mandos_protocol_version;

979

1424

&decrypted_buffer, mc);

980

1425

if(decrypted_buffer_size >= 0){

981

1426

1427

clearerr(stdout);

982

1428

written = 0;

983

1429

while(written < (size_t) decrypted_buffer_size){

984

1430

if(quit_now){

1000

1446

}

1001

1447

written += (size_t)ret;

1002

1448

}

1449

ret = fflush(stdout);

1450

if(ret != 0){

1451

int e = errno;

1452

if(debug){

1453

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

1454

strerror(errno));

1455

}

1456

errno = e;

1457

goto mandos_end;

1458

}

1003

1459

retval = 0;

1004

1460

}

1005

1461

}

1008

1464

1009

1465

mandos_end:

1010

1466

{

1467

if(route_added){

1468

if(not delete_local_route(ip, if_index)){

1469

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

1470

" interface %d", ip, if_index);

1471

}

1472

}

1011

1473

int e = errno;

1012

1474

free(decrypted_buffer);

1013

1475

free(buffer);

1014

1476

if(tcp_sd >= 0){

1015

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

1477

ret = close(tcp_sd);

1016

1478

}

1017

1479

if(ret == -1){

1018

1480

if(e == 0){

1030

1492

return retval;

1031

1493

}

1032

1494

1495

__attribute__((nonnull))

1033

1496

static void resolve_callback(AvahiSServiceResolver *r,

1034

1497

AvahiIfIndex interface,

1035

1498

AvahiProtocol proto,

1043

1506

AVAHI_GCC_UNUSED AvahiStringList *txt,

1044

1507

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1045

1508

flags,

1046

void* mc){

1509

void *mc){

1047

1510

if(r == NULL){

1048

1511

return;

1049

1512

}

1052

1515

timed out */

1053

1516

1054

1517

if(quit_now){

1518

avahi_s_service_resolver_free(r);

1055

1519

return;

1056

1520

}

1057

1521

1102

1566

const char *domain,

1103

1567

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1104

1568

flags,

1105

void* mc){

1569

void *mc){

1106

1570

if(b == NULL){

1107

1571

return;

1108

1572

}

1168

1632

errno = old_errno;

1169

1633

}

1170

1634

1635

__attribute__((nonnull, warn_unused_result))

1171

1636

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

1172

1637

int ret;

1173

error_t ret_errno;

1638

int old_errno;

1174

1639

1175

1640

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

1176

1641

if(s < 0){

1177

ret_errno = errno;

1642

old_errno = errno;

1178

1643

perror_plus("socket");

1179

errno = ret_errno;

1644

errno = old_errno;

1180

1645

return false;

1181

1646

}

1182

strcpy(ifr->ifr_name, ifname);

1647

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

1648

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

1183

1649

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1184

1650

if(ret == -1){

1185

1651

if(debug){

1186

ret_errno = errno;

1652

old_errno = errno;

1187

1653

perror_plus("ioctl SIOCGIFFLAGS");

1188

errno = ret_errno;

1654

errno = old_errno;

1189

1655

}

1190

1656

return false;

1191

1657

}

1192

1658

return true;

1193

1659

}

1194

1660

1661

__attribute__((nonnull, warn_unused_result))

1195

1662

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

1196

1663

1197

1664

/* Reject the loopback device */

1239

1706

* corresponds to an acceptable network device.

1240

1707

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

1241

1708

*/

1709

__attribute__((nonnull, warn_unused_result))

1242

1710

int good_interface(const struct dirent *if_entry){

1243

1711

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

1244

1712

return 0;

1262

1730

/*

1263

1731

* This function determines if a network interface is up.

1264

1732

*/

1733

__attribute__((nonnull, warn_unused_result))

1265

1734

bool interface_is_up(const char *interface){

1266

1735

struct ifreq ifr;

1267

1736

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

1278

1747

/*

1279

1748

* This function determines if a network interface is running

1280

1749

*/

1750

__attribute__((nonnull, warn_unused_result))

1281

1751

bool interface_is_running(const char *interface){

1282

1752

struct ifreq ifr;

1283

1753

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

1291

1761

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

1292

1762

}

1293

1763

1764

__attribute__((nonnull, pure, warn_unused_result))

1294

1765

int notdotentries(const struct dirent *direntry){

1295

1766

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

1296

1767

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

1303

1774

}

1304

1775

1305

1776

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

1777

__attribute__((nonnull, warn_unused_result))

1306

1778

int runnable_hook(const struct dirent *direntry){

1307

1779

int ret;

1308

1780

size_t sret;

1316

1788

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

1317

1789

"abcdefghijklmnopqrstuvwxyz"

1318

1790

"0123456789"

1319

"_-");

1791

"_.-");

1320

1792

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

1321

1793

/* Contains non-allowed characters */

1322

1794

if(debug){

1326

1798

return 0;

1327

1799

}

1328

1800

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);

1801

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

1337

1802

if(ret == -1){

1338

1803

if(debug){

1339

1804

perror_plus("Could not stat hook");

1363

1828

return 1;

1364

1829

}

1365

1830

1831

__attribute__((nonnull, warn_unused_result))

1366

1832

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1367

1833

mandos_context *mc){

1368

1834

int ret;

1372

1838

1373

1839

while(true){

1374

1840

if(mc->current_server == NULL){

1375

if (debug){

1841

if(debug){

1376

1842

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

1377

1843

" No timeout!\n");

1378

1844

}

1379

1845

ret = avahi_simple_poll_iterate(s, -1);

1380

1846

} else {

1381

if (debug){

1847

if(debug){

1382

1848

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

1383

1849

" it, or wait\n");

1384

1850

}

1401

1867

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

1402

1868

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

1403

1869

1404

if (debug){

1870

if(debug){

1405

1871

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

1406

1872

block_time);

1407

1873

}

1429

1895

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

1430

1896

}

1431

1897

if(ret != 0){

1432

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

1898

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

1433

1899

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

1434

1900

}

1435

1901

}

1436

1902

}

1437

1903

}

1438

1904

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,

1905

__attribute__((nonnull))

1906

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

1492

1907

const float delay){

1493

struct dirent **direntries;

1494

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

1495

alphasort);

1908

struct dirent **direntries = NULL;

1909

if(hookdir_fd == -1){

1910

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1911

| O_CLOEXEC);

1912

if(hookdir_fd == -1){

1913

if(errno == ENOENT){

1914

if(debug){

1915

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

1916

" found\n", hookdir);

1917

}

1918

} else {

1919

perror_plus("open");

1920

}

1921

return;

1922

}

1923

}

1924

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

1925

runnable_hook, alphasort);

1496

1926

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");

1927

perror_plus("scandir");

1928

return;

1929

}

1930

struct dirent *direntry;

1931

int ret;

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1937

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

1938

direntry = direntries[i];

1939

if(debug){

1940

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

1941

direntry->d_name);

1504

1942

}

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){

1943

pid_t hook_pid = fork();

1944

if(hook_pid == 0){

1945

/* Child */

1946

/* Raise privileges */

1947

errno = raise_privileges_permanently();

1948

if(errno != 0){

1949

perror_plus("Failed to raise privileges");

1950

_exit(EX_NOPERM);

1951

}

1952

/* Set group */

1953

errno = 0;

1954

ret = setgid(0);

1955

if(ret == -1){

1956

perror_plus("setgid");

1957

_exit(EX_NOPERM);

1958

}

1959

/* Reset supplementary groups */

1960

errno = 0;

1961

ret = setgroups(0, NULL);

1962

if(ret == -1){

1963

perror_plus("setgroups");

1964

_exit(EX_NOPERM);

1965

}

1966

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

1967

if(ret == -1){

1968

perror_plus("setenv");

1969

_exit(EX_OSERR);

1970

}

1971

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

1972

if(ret == -1){

1973

perror_plus("setenv");

1974

_exit(EX_OSERR);

1975

}

1976

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

1977

if(ret == -1){

1978

perror_plus("setenv");

1979

_exit(EX_OSERR);

1980

}

1981

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

1982

if(ret == -1){

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

char *delaystring;

1987

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

1988

if(ret == -1){

1514

1989

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

}

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1573

1994

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

}

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

free(delaystring);

1999

if(connect_to != NULL){

2000

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

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

}

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

2009

if(hook_fd == -1){

2010

perror_plus("openat");

2011

_exit(EXIT_FAILURE);

2012

}

2013

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

2014

perror_plus("close");

2015

_exit(EXIT_FAILURE);

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

ret = close(devnull);

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

2032

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

2033

environ) == -1){

2034

perror_plus("fexecve");

2035

_exit(EXIT_FAILURE);

2036

}

2037

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

int status;

2044

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

2045

perror_plus("waitpid");

2046

free(direntry);

2047

continue;

2048

}

2049

if(WIFEXITED(status)){

2050

if(WEXITSTATUS(status) != 0){

2051

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

2052

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

2053

WEXITSTATUS(status));

2054

free(direntry);

2055

continue;

2056

}

2057

} else if(WIFSIGNALED(status)){

2058

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

2059

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

2060

WTERMSIG(status));

2061

free(direntry);

2062

continue;

1585

2063

} 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;

2064

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

2065

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

2066

free(direntry);

2067

continue;

2068

}

2069

}

2070

if(debug){

2071

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

2072

direntry->d_name);

2073

}

2074

free(direntry);

2075

}

2076

free(direntries);

2077

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

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

1622

2083

}

1623

2084

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;

2085

__attribute__((nonnull, warn_unused_result))

2086

int bring_up_interface(const char *const interface,

2087

const float delay){

2088

int old_errno = errno;

2089

int ret;

1630

2090

struct ifreq network;

1631

2091

unsigned int if_index = if_nametoindex(interface);

1632

2092

if(if_index == 0){

1641

2101

}

1642

2102

1643

2103

if(not interface_is_up(interface)){

1644

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

2104

int ret_errno = 0;

2105

int ioctl_errno = 0;

2106

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

1645

2107

ret_errno = errno;

1646

2108

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

1647

2109

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

2110

errno = old_errno;

1648

2111

return ret_errno;

1649

2112

}

1650

network.ifr_flags |= IFF_UP;

2113

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

1651

2114

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

2115

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

2116

if(sd == -1){

1654

2117

ret_errno = errno;

1655

2118

perror_plus("socket");

1656

2119

errno = old_errno;

1657

2120

return ret_errno;

1658

2121

}

1659

2122

1660

2123

if(quit_now){

1661

close(sd);

2124

ret = close(sd);

2125

if(ret == -1){

2126

perror_plus("close");

2127

}

1662

2128

errno = old_errno;

1663

2129

return EINTR;

1664

2130

}

1668

2134

interface);

1669

2135

}

1670

2136

1671

/* Raise priviliges */

1672

raise_privileges();

2137

/* Raise privileges */

2138

ret_errno = raise_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to raise privileges");

2142

}

1673

2143

1674

2144

#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");

2145

int ret_linux;

2146

bool restore_loglevel = false;

2147

if(ret_errno == 0){

2148

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2149

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

2150

ret_linux = klogctl(8, NULL, 5);

2151

if(ret_linux == -1){

2152

perror_plus("klogctl");

2153

} else {

2154

restore_loglevel = true;

2155

}

1682

2156

}

1683

2157

#endif /* __linux__ */

1684

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

1685

ret_errno = errno;

2158

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

2159

ioctl_errno = errno;

1686

2160

#ifdef __linux__

1687

2161

if(restore_loglevel){

1688

2162

ret_linux = klogctl(7, NULL, 0);

1692

2166

}

1693

2167

#endif /* __linux__ */

1694

2168

1695

/* Lower privileges */

1696

lower_privileges();

2169

/* If raise_privileges() succeeded above */

2170

if(ret_errno == 0){

2171

/* Lower privileges */

2172

ret_errno = lower_privileges();

2173

if(ret_errno != 0){

2174

errno = ret_errno;

2175

perror_plus("Failed to lower privileges");

2176

}

2177

}

1697

2178

1698

2179

/* Close the socket */

1699

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

2180

ret = close(sd);

1700

2181

if(ret == -1){

1701

2182

perror_plus("close");

1702

2183

}

1703

2184

1704

2185

if(ret_setflags == -1){

1705

errno = ret_errno;

2186

errno = ioctl_errno;

1706

2187

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1707

2188

errno = old_errno;

1708

return ret_errno;

2189

return ioctl_errno;

1709

2190

}

1710

2191

} else if(debug){

1711

2192

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

1729

2210

return 0;

1730

2211

}

1731

2212

1732

error_t take_down_interface(const char *const interface){

1733

error_t old_errno = errno;

2213

__attribute__((nonnull, warn_unused_result))

2214

int take_down_interface(const char *const interface){

2215

int old_errno = errno;

1734

2216

struct ifreq network;

1735

2217

unsigned int if_index = if_nametoindex(interface);

1736

2218

if(if_index == 0){

1739

2221

return ENXIO;

1740

2222

}

1741

2223

if(interface_is_up(interface)){

1742

error_t ret_errno = 0;

2224

int ret_errno = 0;

2225

int ioctl_errno = 0;

1743

2226

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

1744

2227

ret_errno = errno;

1745

2228

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

1746

2229

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

2230

errno = old_errno;

1747

2231

return ret_errno;

1748

2232

}

1749

2233

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

1750

2234

1751

2235

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

1752

if(sd < 0){

2236

if(sd == -1){

1753

2237

ret_errno = errno;

1754

2238

perror_plus("socket");

1755

2239

errno = old_errno;

1761

2245

interface);

1762

2246

}

1763

2247

1764

/* Raise priviliges */

1765

raise_privileges();

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

1766

2254

1767

2255

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

1768

ret_errno = errno;

2256

ioctl_errno = errno;

1769

2257

1770

/* Lower privileges */

1771

lower_privileges();

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

1772

2267

1773

2268

/* Close the socket */

1774

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

2269

int ret = close(sd);

1775

2270

if(ret == -1){

1776

2271

perror_plus("close");

1777

2272

}

1778

2273

1779

2274

if(ret_setflags == -1){

1780

errno = ret_errno;

2275

errno = ioctl_errno;

1781

2276

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1782

2277

errno = old_errno;

1783

return ret_errno;

2278

return ioctl_errno;

1784

2279

}

1785

2280

} else if(debug){

1786

2281

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

1792

2287

}

1793

2288

1794

2289

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 };

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

1799

2295

AvahiSServiceBrowser *sb = NULL;

1800

2296

error_t ret_errno;

1801

2297

int ret;

1804

2300

int exitcode = EXIT_SUCCESS;

1805

2301

char *interfaces_to_take_down = NULL;

1806

2302

size_t interfaces_to_take_down_size = 0;

1807

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

1808

bool tempdir_created = false;

2303

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

2304

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

2305

char *tempdir = NULL;

1809

2306

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1810

2307

const char *seckey = PATHDIR "/" SECKEY;

1811

2308

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

1812

2310

char *interfaces_hooks = NULL;

1813

2311

1814

2312

bool gnutls_initialized = false;

1867

2365

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

1868

2366

" Diffie-Hellman key exchange",

1869

2367

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

1870

2373

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

1871

2374

.arg = "STRING",

1872

2375

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

1927

2430

}

1928

2431

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

1929

2432

break;

2433

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

2434

dh_params_file = arg;

2435

break;

1930

2436

case 130: /* --priority */

1931

2437

mc.priority = arg;

1932

2438

break;

1972

2478

.args_doc = "",

1973

2479

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

1974

2480

" passwords from a Mandos server" };

1975

ret = argp_parse(&argp, argc, argv,

1976

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1977

switch(ret){

2481

ret_errno = argp_parse(&argp, argc, argv,

2482

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2483

switch(ret_errno){

1978

2484

case 0:

1979

2485

break;

1980

2486

case ENOMEM:

1981

2487

default:

1982

errno = ret;

2488

errno = ret_errno;

1983

2489

perror_plus("argp_parse");

1984

2490

exitcode = EX_OSERR;

1985

2491

goto end;

1988

2494

goto end;

1989

2495

}

1990

2496

}

1991

2497

1992

2498

{

1993

2499

/* Work around Debian bug #633582:

1994

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

2500

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

1995

2501

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2502

/* Re-raise privileges */

2503

ret = raise_privileges();

2504

if(ret != 0){

2505

errno = ret;

2506

perror_plus("Failed to raise privileges");

2507

} else {

1998

2508

struct stat st;

1999

2509

2000

2510

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

2014

2524

}

2015

2525

}

2016

2526

}

2017

TEMP_FAILURE_RETRY(close(seckey_fd));

2527

close(seckey_fd);

2018

2528

}

2019

2529

}

2020

2530

2021

2531

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

2022

2532

int pubkey_fd = open(pubkey, O_RDONLY);

2023

2533

if(pubkey_fd == -1){

2035

2545

}

2036

2546

}

2037

2547

}

2038

TEMP_FAILURE_RETRY(close(pubkey_fd));

2039

}

2040

}

2041

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

2042

2574

/* Lower privileges */

2043

lower_privileges();

2575

ret = lower_privileges();

2576

if(ret != 0){

2577

errno = ret;

2578

perror_plus("Failed to lower privileges");

2579

}

2044

2580

}

2045

2581

}

2046

2582

2072

2608

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

2073

2609

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

2074

2610

}

2075

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

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

2079

2613

}

2080

2614

2081

2615

if(not debug){

2159

2693

2160

2694

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

2161

2695

if(mc.interfaces == NULL){

2162

struct dirent **direntries;

2696

struct dirent **direntries = NULL;

2163

2697

/* Look for any good interfaces */

2164

2698

ret = scandir(sys_class_net, &direntries, good_interface,

2165

2699

alphasort);

2171

2705

if(ret_errno != 0){

2172

2706

errno = ret_errno;

2173

2707

perror_plus("argz_add");

2708

free(direntries[i]);

2174

2709

continue;

2175

2710

}

2176

2711

if(debug){

2177

2712

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

2178

2713

direntries[i]->d_name);

2179

2714

}

2715

free(direntries[i]);

2180

2716

}

2181

2717

free(direntries);

2182

2718

} else {

2183

free(direntries);

2719

if(ret == 0){

2720

free(direntries);

2721

}

2184

2722

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

2185

2723

exitcode = EXIT_FAILURE;

2186

2724

goto end;

2209

2747

break;

2210

2748

}

2211

2749

bool interface_was_up = interface_is_up(interface);

2212

ret = bring_up_interface(interface, delay);

2750

errno = bring_up_interface(interface, delay);

2213

2751

if(not interface_was_up){

2214

if(ret != 0){

2215

errno = ret;

2216

perror_plus("Failed to bring up interface");

2752

if(errno != 0){

2753

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

2754

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

2217

2755

} 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;

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

2223

2760

perror_plus("argz_add");

2224

2761

}

2225

2762

}

2243

2780

goto end;

2244

2781

}

2245

2782

2246

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

2783

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

2247

2784

if(ret == -1){

2248

2785

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

2249

2786

exitcode = EX_UNAVAILABLE;

2256

2793

goto end;

2257

2794

}

2258

2795

2259

if(mkdtemp(tempdir) == NULL){

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

2260

2806

perror_plus("mkdtemp");

2261

2807

goto end;

2262

2808

}

2263

tempdir_created = true;

2264

2809

2265

2810

if(quit_now){

2266

2811

goto end;

2341

2886

sleep((unsigned int)retry_interval);

2342

2887

}

2343

2888

2344

if (not quit_now){

2889

if(not quit_now){

2345

2890

exitcode = EXIT_SUCCESS;

2346

2891

}

2347

2892

2363

2908

2364

2909

/* Allocate a new server */

2365

2910

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2366

&config, NULL, NULL, &ret_errno);

2911

&config, NULL, NULL, &ret);

2367

2912

2368

2913

/* Free the Avahi configuration data */

2369

2914

avahi_server_config_free(&config);

2372

2917

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

2373

2918

if(mc.server == NULL){

2374

2919

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

2375

avahi_strerror(ret_errno));

2920

avahi_strerror(ret));

2376

2921

exitcode = EX_UNAVAILABLE;

2377

2922

goto end;

2378

2923

}

2402

2947

if(debug){

2403

2948

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

2404

2949

}

2405

2950

2406

2951

ret = avahi_loop_with_timeout(simple_poll,

2407

2952

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

2408

2953

if(debug){

2413

2958

end:

2414

2959

2415

2960

if(debug){

2416

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

2961

if(signal_received){

2962

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

2963

argv[0], signal_received,

2964

strsignal(signal_received));

2965

} else {

2966

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

2967

}

2417

2968

}

2418

2969

2419

2970

/* Cleanup things */

2430

2981

2431

2982

if(gnutls_initialized){

2432

2983

gnutls_certificate_free_credentials(mc.cred);

2433

gnutls_global_deinit();

2434

2984

gnutls_dh_params_deinit(mc.dh_params);

2435

2985

}

2436

2986

2444

2994

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

2445

2995

while(mc.current_server != NULL){

2446

2996

server *next = mc.current_server->next;

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic push

2999

#pragma GCC diagnostic ignored "-Wcast-qual"

3000

#endif

3001

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

3002

#ifdef __GNUC__

3003

#pragma GCC diagnostic pop

3004

#endif

2447

3005

free(mc.current_server);

2448

3006

mc.current_server = next;

2449

3007

}

2450

3008

}

2451

3009

2452

/* Re-raise priviliges */

3010

/* Re-raise privileges */

2453

3011

{

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();

3012

ret = raise_privileges();

3013

if(ret != 0){

3014

errno = ret;

3015

perror_plus("Failed to raise privileges");

3016

} else {

3017

3018

/* Run network hooks */

3019

run_network_hooks("stop", interfaces_hooks != NULL ?

3020

interfaces_hooks : "", delay);

3021

3022

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

3023

{

3024

char *interface = NULL;

3025

while((interface=argz_next(interfaces_to_take_down,

3026

interfaces_to_take_down_size,

3027

interface))){

3028

ret = take_down_interface(interface);

3029

if(ret != 0){

3030

errno = ret;

3031

perror_plus("Failed to take down interface");

3032

}

3033

}

3034

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

3035

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

3036

" down\n");

3037

}

3038

}

3039

}

3040

3041

ret = lower_privileges_permanently();

3042

if(ret != 0){

3043

errno = ret;

3044

perror_plus("Failed to lower privileges permanently");

3045

}

2479

3046

}

2480

3047

2481

3048

free(interfaces_to_take_down);

2482

3049

free(interfaces_hooks);

2483

3050

3051

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

3052

uintmax_t level){

3053

struct dirent **direntries = NULL;

3054

int dret;

3055

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

3056

O_RDONLY

3057

| O_NOFOLLOW

3058

| O_DIRECTORY

3059

| O_PATH));

3060

if(dir_fd == -1){

3061

perror_plus("open");

3062

}

3063

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

3064

notdotentries, alphasort);

3065

if(numentries >= 0){

3066

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

3067

if(debug){

3068

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

3069

dirname, direntries[i]->d_name);

3070

}

3071

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

3072

if(dret == -1){

3073

if(errno == EISDIR){

3074

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

3075

AT_REMOVEDIR);

3076

}

3077

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

3078

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

3079

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

3080

/* Recurse only in this special case */

3081

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

3082

dret = 0;

3083

}

3084

if(dret == -1){

3085

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

3086

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

3087

}

3088

}

3089

free(direntries[i]);

3090

}

3091

3092

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

3093

free(direntries);

3094

if(numentries == -1){

3095

perror_plus("scandirat");

3096

}

3097

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3098

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

3099

perror_plus("rmdir");

3100

}

3101

} else {

3102

perror_plus("scandirat");

3103

}

3104

close(dir_fd);

3105

}

3106

2484

3107

/* 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

}

3108

if(tempdir != NULL){

3109

clean_dir_at(-1, tempdir, 0);

2518

3110

}

2519

3111

2520

3112

if(quit_now){