/mandos/trunk : revision 669

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

41

42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

strtof(), abort() */

48

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

49

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

50

asprintf(), strncpy() */

49

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

50

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

51

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

52

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

53

sockaddr_in6, PF_INET6,

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

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

61

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

62

*/

63

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

64

strtoimax() */

65

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

66

EAI_SYSTEM, ENETUNREACH,

67

EHOSTUNREACH, ECONNREFUSED, EPROTO,

68

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

69

ENOTEMPTY,

65

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

70

66

program_invocation_short_name */

71

67

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

72

68

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

77

73

*/

78

74

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

79

75

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

80

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

81

unlinkat() */

76

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

82

77

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

83

78

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

84

79

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

146

141

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

147

142

char *connect_to = NULL;

148

143

const char *hookdir = HOOKDIR;

149

int hookdir_fd = -1;

150

144

uid_t uid = 65534;

151

145

gid_t gid = 65534;

152

146

189

183

perror(print_text);

190

184

}

191

185

192

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

186

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

193

187

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

194

188

va_list ap;

195

189

va_start (ap, format);

204

198

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

205

199

* "buffer_length" is how much is already used.

206

200

*/

207

__attribute__((nonnull, warn_unused_result))

208

201

size_t incbuffer(char **buffer, size_t buffer_length,

209

202

size_t buffer_capacity){

210

203

if(buffer_length + BUFFER_SIZE > buffer_capacity){

223

216

}

224

217

225

218

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

226

__attribute__((nonnull, warn_unused_result))

227

219

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

228

220

int af, server **current_server){

229

221

int ret;

238

230

.af = af };

239

231

if(new_server->ip == NULL){

240

232

perror_plus("strdup");

241

free(new_server);

242

233

return false;

243

234

}

244

235

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

245

236

if(ret == -1){

246

237

perror_plus("clock_gettime");

247

#ifdef __GNUC__

248

#pragma GCC diagnostic push

249

#pragma GCC diagnostic ignored "-Wcast-qual"

250

#endif

251

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

252

#ifdef __GNUC__

253

#pragma GCC diagnostic pop

254

#endif

255

free(new_server);

256

238

return false;

257

239

}

258

240

/* Special case of first server */

260

242

new_server->next = new_server;

261

243

new_server->prev = new_server;

262

244

*current_server = new_server;

245

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

263

246

} else {

264

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

265

247

new_server->next = *current_server;

266

248

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

267

249

new_server->prev->next = new_server;

273

255

/*

274

256

* Initialize GPGME.

275

257

*/

276

__attribute__((nonnull, warn_unused_result))

277

static bool init_gpgme(const char * const seckey,

278

const char * const pubkey,

279

const char * const tempdir,

280

mandos_context *mc){

258

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

259

const char *tempdir, mandos_context *mc){

281

260

gpgme_error_t rc;

282

261

gpgme_engine_info_t engine_info;

283

262

284

263

/*

285

264

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

286

265

*/

287

bool import_key(const char * const filename){

266

bool import_key(const char *filename){

288

267

int ret;

289

268

int fd;

290

269

gpgme_data_t pgp_data;

309

288

return false;

310

289

}

311

290

312

ret = close(fd);

291

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

313

292

if(ret == -1){

314

293

perror_plus("close");

315

294

}

371

350

* Decrypt OpenPGP data.

372

351

* Returns -1 on error

373

352

*/

374

__attribute__((nonnull, warn_unused_result))

375

353

static ssize_t pgp_packet_decrypt(const char *cryptotext,

376

354

size_t crypto_size,

377

355

char **plaintext,

497

475

return plaintext_length;

498

476

}

499

477

500

__attribute__((warn_unused_result, const))

501

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

502

if(str == NULL)

503

return "(unknown)";

504

return str;

505

}

506

507

__attribute__((warn_unused_result))

508

static const char *safer_gnutls_strerror(int value){

478

static const char * safer_gnutls_strerror(int value){

509

479

const char *ret = gnutls_strerror(value);

510

return safe_string(ret);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

511

483

}

512

484

513

485

/* GnuTLS log function callback */

514

__attribute__((nonnull))

515

486

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

516

487

const char* string){

517

488

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

518

489

}

519

490

520

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

521

491

static int init_gnutls_global(const char *pubkeyfilename,

522

492

const char *seckeyfilename,

523

const char *dhparamsfilename,

524

493

mandos_context *mc){

525

494

int ret;

526

unsigned int uret;

527

495

528

496

if(debug){

529

497

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

530

498

}

531

499

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

532

507

if(debug){

533

508

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

534

509

* - GnuTLS manual

542

517

if(ret != GNUTLS_E_SUCCESS){

543

518

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

544

519

safer_gnutls_strerror(ret));

520

gnutls_global_deinit();

545

521

return -1;

546

522

}

547

523

572

548

safer_gnutls_strerror(ret));

573

549

goto globalfail;

574

550

}

575

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

576

if(dhparamsfilename != NULL){

577

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

578

do {

579

int dhpfile = open(dhparamsfilename, O_RDONLY);

580

if(dhpfile == -1){

581

perror_plus("open");

582

dhparamsfilename = NULL;

583

break;

584

}

585

size_t params_capacity = 0;

586

while(true){

587

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

588

(size_t)params.size,

589

(size_t)params_capacity);

590

if(params_capacity == 0){

591

perror_plus("incbuffer");

592

free(params.data);

593

params.data = NULL;

594

dhparamsfilename = NULL;

595

break;

596

}

597

ssize_t bytes_read = read(dhpfile,

598

params.data + params.size,

599

BUFFER_SIZE);

600

/* EOF */

601

if(bytes_read == 0){

602

break;

603

}

604

/* check bytes_read for failure */

605

if(bytes_read < 0){

606

perror_plus("read");

607

free(params.data);

608

params.data = NULL;

609

dhparamsfilename = NULL;

610

break;

611

}

612

params.size += (unsigned int)bytes_read;

613

}

614

if(params.data == NULL){

615

dhparamsfilename = NULL;

616

}

617

if(dhparamsfilename == NULL){

618

break;

619

}

620

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

621

GNUTLS_X509_FMT_PEM);

622

if(ret != GNUTLS_E_SUCCESS){

623

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

624

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

625

safer_gnutls_strerror(ret));

626

dhparamsfilename = NULL;

627

}

628

} while(false);

629

}

630

if(dhparamsfilename == NULL){

631

if(mc->dh_bits == 0){

632

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

633

/* Try to read the private key file */

634

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

635

do {

636

int secfile = open(seckeyfilename, O_RDONLY);

637

if(secfile == -1){

638

perror_plus("open");

639

break;

640

}

641

size_t buffer_capacity = 0;

642

while(true){

643

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

644

(size_t)buffer.size,

645

(size_t)buffer_capacity);

646

if(buffer_capacity == 0){

647

perror_plus("incbuffer");

648

free(buffer.data);

649

buffer.data = NULL;

650

break;

651

}

652

ssize_t bytes_read = read(secfile,

653

buffer.data + buffer.size,

654

BUFFER_SIZE);

655

/* EOF */

656

if(bytes_read == 0){

657

break;

658

}

659

/* check bytes_read for failure */

660

if(bytes_read < 0){

661

perror_plus("read");

662

free(buffer.data);

663

buffer.data = NULL;

664

break;

665

}

666

buffer.size += (unsigned int)bytes_read;

667

}

668

close(secfile);

669

} while(false);

670

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

671

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

672

if(buffer.data != NULL){

673

{

674

gnutls_openpgp_privkey_t privkey = NULL;

675

ret = gnutls_openpgp_privkey_init(&privkey);

676

if(ret != GNUTLS_E_SUCCESS){

677

fprintf_plus(stderr, "Error initializing OpenPGP key"

678

" structure: %s",

679

safer_gnutls_strerror(ret));

680

free(buffer.data);

681

buffer.data = NULL;

682

} else {

683

ret = gnutls_openpgp_privkey_import

684

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

685

if(ret != GNUTLS_E_SUCCESS){

686

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

687

safer_gnutls_strerror(ret));

688

privkey = NULL;

689

}

690

free(buffer.data);

691

buffer.data = NULL;

692

if(privkey != NULL){

693

/* Use private key to suggest an appropriate

694

sec_param */

695

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

696

gnutls_openpgp_privkey_deinit(privkey);

697

if(debug){

698

fprintf_plus(stderr, "This OpenPGP key implies using"

699

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

700

safe_string(gnutls_sec_param_get_name

701

(sec_param)));

702

}

703

}

704

}

705

}

706

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

707

/* Err on the side of caution */

708

sec_param = GNUTLS_SEC_PARAM_ULTRA;

709

if(debug){

710

fprintf_plus(stderr, "Falling back to security parameter"

711

" \"%s\"\n",

712

safe_string(gnutls_sec_param_get_name

713

(sec_param)));

714

}

715

}

716

}

717

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

718

if(uret != 0){

719

mc->dh_bits = uret;

720

if(debug){

721

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

722

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

723

safe_string(gnutls_sec_param_get_name

724

(sec_param)),

725

mc->dh_bits);

726

}

727

} else {

728

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

729

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

730

safe_string(gnutls_sec_param_get_name

731

(sec_param)),

732

safer_gnutls_strerror(ret));

733

goto globalfail;

734

}

735

} else if(debug){

736

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

737

mc->dh_bits);

738

}

739

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

740

if(ret != GNUTLS_E_SUCCESS){

741

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

742

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

743

safer_gnutls_strerror(ret));

744

goto globalfail;

745

}

746

}

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

747

558

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

748

559

749

560

return 0;

751

562

globalfail:

752

563

753

564

gnutls_certificate_free_credentials(mc->cred);

565

gnutls_global_deinit();

754

566

gnutls_dh_params_deinit(mc->dh_params);

755

567

return -1;

756

568

}

757

569

758

__attribute__((nonnull, warn_unused_result))

759

570

static int init_gnutls_session(gnutls_session_t *session,

760

571

mandos_context *mc){

761

572

int ret;

808

619

/* ignore client certificate if any. */

809

620

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

810

621

622

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

623

811

624

return 0;

812

625

}

813

626

815

628

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

816

629

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

817

630

818

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

819

__attribute__((warn_unused_result))

820

int raise_privileges(void){

821

int old_errno = errno;

822

int ret = 0;

823

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

824

ret = errno;

825

}

826

errno = old_errno;

827

return ret;

828

}

829

830

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

831

__attribute__((warn_unused_result))

832

int raise_privileges_permanently(void){

833

int old_errno = errno;

834

int ret = raise_privileges();

835

if(ret != 0){

836

errno = old_errno;

837

return ret;

838

}

839

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

840

ret = errno;

841

}

842

errno = old_errno;

843

return ret;

844

}

845

846

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

847

__attribute__((warn_unused_result))

848

int lower_privileges(void){

849

int old_errno = errno;

850

int ret = 0;

851

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

852

ret = errno;

853

}

854

errno = old_errno;

855

return ret;

856

}

857

858

/* Lower privileges permanently */

859

__attribute__((warn_unused_result))

860

int lower_privileges_permanently(void){

861

int old_errno = errno;

862

int ret = 0;

863

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

864

ret = errno;

865

}

866

errno = old_errno;

867

return ret;

868

}

869

870

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

871

__attribute__((nonnull, warn_unused_result))

872

static bool add_delete_local_route(const bool add,

873

const char *address,

874

AvahiIfIndex if_index){

875

int ret;

876

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

877

char add_arg[] = "add";

878

char delete_arg[] = "delete";

879

char debug_flag[] = "--debug";

880

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

881

if(pluginhelperdir == NULL){

882

if(debug){

883

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

884

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

885

}

886

return false;

887

}

888

889

char interface[IF_NAMESIZE];

890

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

891

perror_plus("if_indextoname");

892

return false;

893

}

894

895

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

896

if(devnull == -1){

897

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

898

return false;

899

}

900

pid_t pid = fork();

901

if(pid == 0){

902

/* Child */

903

/* Raise privileges */

904

errno = raise_privileges_permanently();

905

if(errno != 0){

906

perror_plus("Failed to raise privileges");

907

/* _exit(EX_NOPERM); */

908

} else {

909

/* Set group */

910

errno = 0;

911

ret = setgid(0);

912

if(ret == -1){

913

perror_plus("setgid");

914

_exit(EX_NOPERM);

915

}

916

/* Reset supplementary groups */

917

errno = 0;

918

ret = setgroups(0, NULL);

919

if(ret == -1){

920

perror_plus("setgroups");

921

_exit(EX_NOPERM);

922

}

923

}

924

ret = dup2(devnull, STDIN_FILENO);

925

if(ret == -1){

926

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

927

_exit(EX_OSERR);

928

}

929

ret = close(devnull);

930

if(ret == -1){

931

perror_plus("close");

932

_exit(EX_OSERR);

933

}

934

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

935

if(ret == -1){

936

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

937

_exit(EX_OSERR);

938

}

939

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

940

O_RDONLY

941

| O_DIRECTORY

942

| O_PATH

943

| O_CLOEXEC));

944

if(helperdir_fd == -1){

945

perror_plus("open");

946

_exit(EX_UNAVAILABLE);

947

}

948

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

949

helper, O_RDONLY));

950

if(helper_fd == -1){

951

perror_plus("openat");

952

close(helperdir_fd);

953

_exit(EX_UNAVAILABLE);

954

}

955

close(helperdir_fd);

956

#ifdef __GNUC__

957

#pragma GCC diagnostic push

958

#pragma GCC diagnostic ignored "-Wcast-qual"

959

#endif

960

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

961

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

962

interface, debug ? debug_flag : NULL, NULL },

963

environ) == -1){

964

#ifdef __GNUC__

965

#pragma GCC diagnostic pop

966

#endif

967

perror_plus("fexecve");

968

_exit(EXIT_FAILURE);

969

}

970

}

971

if(pid == -1){

972

perror_plus("fork");

973

return false;

974

}

975

int status;

976

pid_t pret = -1;

977

errno = 0;

978

do {

979

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

980

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

981

int errno_raising = 0;

982

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

983

errno_raising = errno;

984

perror_plus("Failed to raise privileges in order to"

985

" kill helper program");

986

}

987

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

988

perror_plus("kill");

989

}

990

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

991

perror_plus("Failed to lower privileges after killing"

992

" helper program");

993

}

994

return false;

995

}

996

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

997

if(pret == -1){

998

perror_plus("waitpid");

999

return false;

1000

}

1001

if(WIFEXITED(status)){

1002

if(WEXITSTATUS(status) != 0){

1003

fprintf_plus(stderr, "Error: iprouteadddel exited"

1004

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

1005

return false;

1006

}

1007

return true;

1008

}

1009

if(WIFSIGNALED(status)){

1010

fprintf_plus(stderr, "Error: iprouteadddel died by"

1011

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

1012

return false;

1013

}

1014

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

1015

return false;

1016

}

1017

1018

__attribute__((nonnull, warn_unused_result))

1019

static bool add_local_route(const char *address,

1020

AvahiIfIndex if_index){

1021

if(debug){

1022

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

1023

}

1024

return add_delete_local_route(true, address, if_index);

1025

}

1026

1027

__attribute__((nonnull, warn_unused_result))

1028

static bool delete_local_route(const char *address,

1029

AvahiIfIndex if_index){

1030

if(debug){

1031

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

1032

}

1033

return add_delete_local_route(false, address, if_index);

1034

}

1035

1036

631

/* Called when a Mandos server is found */

1037

__attribute__((nonnull, warn_unused_result))

1038

632

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

1039

633

AvahiIfIndex if_index,

1040

634

int af, mandos_context *mc){

1049

643

int retval = -1;

1050

644

gnutls_session_t session;

1051

645

int pf; /* Protocol family */

1052

bool route_added = false;

1053

646

1054

647

errno = 0;

1055

648

1113

706

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

1114

707

}

1115

708

1116

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

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

710

if(tcp_sd < 0){

1118

711

int e = errno;

1119

712

perror_plus("socket");

1126

719

goto mandos_end;

1127

720

}

1128

721

722

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

1129

723

if(af == AF_INET6){

1130

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

1131

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

1132

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

724

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

725

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

1133

726

} else { /* IPv4 */

1134

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

1135

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

1136

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

727

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

728

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

1137

729

}

1138

730

if(ret < 0 ){

1139

731

int e = errno;

1148

740

goto mandos_end;

1149

741

}

1150

742

if(af == AF_INET6){

1151

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

743

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

1152

744

if(IN6_IS_ADDR_LINKLOCAL

1153

745

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

1154

746

if(if_index == AVAHI_IF_UNSPEC){

1209

801

goto mandos_end;

1210

802

}

1211

803

1212

while(true){

1213

if(af == AF_INET6){

1214

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

1215

sizeof(struct sockaddr_in6));

1216

} else {

1217

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

1218

sizeof(struct sockaddr_in));

1219

}

1220

if(ret < 0){

1221

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

1222

and if_index != AVAHI_IF_UNSPEC

1223

and connect_to == NULL

1224

and not route_added and

1225

((af == AF_INET6 and not

1226

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1227

&to)->sin6_addr)))

1228

or (af == AF_INET and

1229

/* Not a a IPv4LL address */

1230

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

1231

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

1232

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

1233

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

1234

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

1235

connect to a Mandos server announced by Avahi on a server

1236

host with a global address. Work around this by retrying

1237

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

1238

1239

Avahi bug reference:

1240

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

1241

https://bugs.debian.org/587961

1242

*/

1243

if(debug){

1244

fprintf_plus(stderr, "Mandos server unreachable, trying"

1245

" direct route\n");

1246

}

1247

int e = errno;

1248

route_added = add_local_route(ip, if_index);

1249

if(route_added){

1250

continue;

1251

}

1252

errno = e;

1253

}

1254

if(errno != ECONNREFUSED or debug){

1255

int e = errno;

1256

perror_plus("connect");

1257

errno = e;

1258

}

1259

goto mandos_end;

1260

}

1261

1262

if(quit_now){

1263

errno = EINTR;

1264

goto mandos_end;

1265

}

1266

break;

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;

1267

823

}

1268

824

1269

825

const char *out = mandos_protocol_version;

1423

979

&decrypted_buffer, mc);

1424

980

if(decrypted_buffer_size >= 0){

1425

981

1426

clearerr(stdout);

1427

982

written = 0;

1428

983

while(written < (size_t) decrypted_buffer_size){

1429

984

if(quit_now){

1445

1000

}

1446

1001

written += (size_t)ret;

1447

1002

}

1448

ret = fflush(stdout);

1449

if(ret != 0){

1450

int e = errno;

1451

if(debug){

1452

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

1453

strerror(errno));

1454

}

1455

errno = e;

1456

goto mandos_end;

1457

}

1458

1003

retval = 0;

1459

1004

}

1460

1005

}

1463

1008

1464

1009

mandos_end:

1465

1010

{

1466

if(route_added){

1467

if(not delete_local_route(ip, if_index)){

1468

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

1469

" interface %d", ip, if_index);

1470

}

1471

}

1472

1011

int e = errno;

1473

1012

free(decrypted_buffer);

1474

1013

free(buffer);

1475

1014

if(tcp_sd >= 0){

1476

ret = close(tcp_sd);

1015

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

1477

1016

}

1478

1017

if(ret == -1){

1479

1018

if(e == 0){

1491

1030

return retval;

1492

1031

}

1493

1032

1494

__attribute__((nonnull))

1495

1033

static void resolve_callback(AvahiSServiceResolver *r,

1496

1034

AvahiIfIndex interface,

1497

1035

AvahiProtocol proto,

1505

1043

AVAHI_GCC_UNUSED AvahiStringList *txt,

1506

1044

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1507

1045

flags,

1508

void *mc){

1046

void* mc){

1509

1047

if(r == NULL){

1510

1048

return;

1511

1049

}

1514

1052

timed out */

1515

1053

1516

1054

if(quit_now){

1517

avahi_s_service_resolver_free(r);

1518

1055

return;

1519

1056

}

1520

1057

1565

1102

const char *domain,

1566

1103

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1567

1104

flags,

1568

void *mc){

1105

void* mc){

1569

1106

if(b == NULL){

1570

1107

return;

1571

1108

}

1631

1168

errno = old_errno;

1632

1169

}

1633

1170

1634

__attribute__((nonnull, warn_unused_result))

1635

1171

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

1636

1172

int ret;

1637

int old_errno;

1173

error_t ret_errno;

1638

1174

1639

1175

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

1640

1176

if(s < 0){

1641

old_errno = errno;

1177

ret_errno = errno;

1642

1178

perror_plus("socket");

1643

errno = old_errno;

1179

errno = ret_errno;

1644

1180

return false;

1645

1181

}

1646

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

1647

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

1182

strcpy(ifr->ifr_name, ifname);

1648

1183

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1649

1184

if(ret == -1){

1650

1185

if(debug){

1651

old_errno = errno;

1186

ret_errno = errno;

1652

1187

perror_plus("ioctl SIOCGIFFLAGS");

1653

errno = old_errno;

1188

errno = ret_errno;

1654

1189

}

1655

1190

return false;

1656

1191

}

1657

1192

return true;

1658

1193

}

1659

1194

1660

__attribute__((nonnull, warn_unused_result))

1661

1195

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

1662

1196

1663

1197

/* Reject the loopback device */

1705

1239

* corresponds to an acceptable network device.

1706

1240

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

1707

1241

*/

1708

__attribute__((nonnull, warn_unused_result))

1709

1242

int good_interface(const struct dirent *if_entry){

1710

1243

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

1711

1244

return 0;

1729

1262

/*

1730

1263

* This function determines if a network interface is up.

1731

1264

*/

1732

__attribute__((nonnull, warn_unused_result))

1733

1265

bool interface_is_up(const char *interface){

1734

1266

struct ifreq ifr;

1735

1267

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

1746

1278

/*

1747

1279

* This function determines if a network interface is running

1748

1280

*/

1749

__attribute__((nonnull, warn_unused_result))

1750

1281

bool interface_is_running(const char *interface){

1751

1282

struct ifreq ifr;

1752

1283

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

1760

1291

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

1761

1292

}

1762

1293

1763

__attribute__((nonnull, pure, warn_unused_result))

1764

1294

int notdotentries(const struct dirent *direntry){

1765

1295

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

1766

1296

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

1773

1303

}

1774

1304

1775

1305

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

1776

__attribute__((nonnull, warn_unused_result))

1777

1306

int runnable_hook(const struct dirent *direntry){

1778

1307

int ret;

1779

1308

size_t sret;

1787

1316

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

1788

1317

"abcdefghijklmnopqrstuvwxyz"

1789

1318

"0123456789"

1790

"_.-");

1319

"_-");

1791

1320

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

1792

1321

/* Contains non-allowed characters */

1793

1322

if(debug){

1797

1326

return 0;

1798

1327

}

1799

1328

1800

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

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

1337

if(ret == -1){

1802

1338

if(debug){

1803

1339

perror_plus("Could not stat hook");

1827

1363

return 1;

1828

1364

}

1829

1365

1830

__attribute__((nonnull, warn_unused_result))

1831

1366

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1832

1367

mandos_context *mc){

1833

1368

int ret;

1837

1372

1838

1373

while(true){

1839

1374

if(mc->current_server == NULL){

1840

if(debug){

1375

if (debug){

1841

1376

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

1842

1377

" No timeout!\n");

1843

1378

}

1844

1379

ret = avahi_simple_poll_iterate(s, -1);

1845

1380

} else {

1846

if(debug){

1381

if (debug){

1847

1382

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

1848

1383

" it, or wait\n");

1849

1384

}

1866

1401

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

1867

1402

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

1868

1403

1869

if(debug){

1404

if (debug){

1870

1405

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

1871

1406

block_time);

1872

1407

}

1894

1429

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

1895

1430

}

1896

1431

if(ret != 0){

1897

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

1432

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

1898

1433

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

1899

1434

}

1900

1435

}

1901

1436

}

1902

1437

}

1903

1438

1904

__attribute__((nonnull))

1905

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

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,

1906

1492

const float delay){

1907

struct dirent **direntries = NULL;

1908

if(hookdir_fd == -1){

1909

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1910

| O_CLOEXEC);

1911

if(hookdir_fd == -1){

1912

if(errno == ENOENT){

1913

if(debug){

1914

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

1915

" found\n", hookdir);

1916

}

1917

} else {

1918

perror_plus("open");

1919

}

1920

return;

1921

}

1922

}

1923

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

1924

runnable_hook, alphasort);

1493

struct dirent **direntries;

1494

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

1495

alphasort);

1925

1496

if(numhooks == -1){

1926

perror_plus("scandir");

1927

return;

1928

}

1929

struct dirent *direntry;

1930

int ret;

1931

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

1932

if(devnull == -1){

1933

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

1934

return;

1935

}

1936

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

1937

direntry = direntries[i];

1938

if(debug){

1939

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

1940

direntry->d_name);

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");

1941

1504

}

1942

pid_t hook_pid = fork();

1943

if(hook_pid == 0){

1944

/* Child */

1945

/* Raise privileges */

1946

errno = raise_privileges_permanently();

1947

if(errno != 0){

1948

perror_plus("Failed to raise privileges");

1949

_exit(EX_NOPERM);

1950

}

1951

/* Set group */

1952

errno = 0;

1953

ret = setgid(0);

1954

if(ret == -1){

1955

perror_plus("setgid");

1956

_exit(EX_NOPERM);

1957

}

1958

/* Reset supplementary groups */

1959

errno = 0;

1960

ret = setgroups(0, NULL);

1961

if(ret == -1){

1962

perror_plus("setgroups");

1963

_exit(EX_NOPERM);

1964

}

1965

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

1966

if(ret == -1){

1967

perror_plus("setenv");

1968

_exit(EX_OSERR);

1969

}

1970

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

1971

if(ret == -1){

1972

perror_plus("setenv");

1973

_exit(EX_OSERR);

1974

}

1975

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

1976

if(ret == -1){

1977

perror_plus("setenv");

1978

_exit(EX_OSERR);

1979

}

1980

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

1981

if(ret == -1){

1982

perror_plus("setenv");

1983

_exit(EX_OSERR);

1984

}

1985

char *delaystring;

1986

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

1987

if(ret == -1){

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){

1988

1514

perror_plus("asprintf");

1989

_exit(EX_OSERR);

1990

}

1991

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

1992

if(ret == -1){

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

}

1993

1573

free(delaystring);

1994

perror_plus("setenv");

1995

_exit(EX_OSERR);

1996

}

1997

free(delaystring);

1998

if(connect_to != NULL){

1999

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

2000

if(ret == -1){

2001

perror_plus("setenv");

2002

_exit(EX_OSERR);

2003

}

2004

}

2005

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

2006

direntry->d_name,

2007

O_RDONLY));

2008

if(hook_fd == -1){

2009

perror_plus("openat");

2010

_exit(EXIT_FAILURE);

2011

}

2012

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

2013

perror_plus("close");

2014

_exit(EXIT_FAILURE);

2015

}

2016

ret = dup2(devnull, STDIN_FILENO);

2017

if(ret == -1){

2018

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

2019

_exit(EX_OSERR);

2020

}

2021

ret = close(devnull);

2022

if(ret == -1){

2023

perror_plus("close");

2024

_exit(EX_OSERR);

2025

}

2026

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2027

if(ret == -1){

2028

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

2029

_exit(EX_OSERR);

2030

}

2031

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

2032

environ) == -1){

2033

perror_plus("fexecve");

2034

_exit(EXIT_FAILURE);

2035

}

2036

} else {

2037

if(hook_pid == -1){

2038

perror_plus("fork");

2039

free(direntry);

2040

continue;

2041

}

2042

int status;

2043

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

2044

perror_plus("waitpid");

2045

free(direntry);

2046

continue;

2047

}

2048

if(WIFEXITED(status)){

2049

if(WEXITSTATUS(status) != 0){

2050

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

2051

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

2052

WEXITSTATUS(status));

2053

free(direntry);

2054

continue;

2055

}

2056

} else if(WIFSIGNALED(status)){

2057

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

2058

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

2059

WTERMSIG(status));

2060

free(direntry);

2061

continue;

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

}

2062

1585

} else {

2063

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

2064

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

2065

free(direntry);

2066

continue;

2067

}

2068

}

2069

if(debug){

2070

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

2071

direntry->d_name);

2072

}

2073

free(direntry);

2074

}

2075

free(direntries);

2076

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

2077

perror_plus("close");

2078

} else {

2079

hookdir_fd = -1;

2080

}

2081

close(devnull);

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;

2082

1622

}

2083

1623

2084

__attribute__((nonnull, warn_unused_result))

2085

int bring_up_interface(const char *const interface,

2086

const float delay){

2087

int old_errno = errno;

2088

int ret;

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;

2089

1630

struct ifreq network;

2090

1631

unsigned int if_index = if_nametoindex(interface);

2091

1632

if(if_index == 0){

2100

1641

}

2101

1642

2102

1643

if(not interface_is_up(interface)){

2103

int ret_errno = 0;

2104

int ioctl_errno = 0;

2105

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

1644

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

2106

1645

ret_errno = errno;

2107

1646

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

2108

1647

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

2109

errno = old_errno;

2110

1648

return ret_errno;

2111

1649

}

2112

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

1650

network.ifr_flags |= IFF_UP;

2113

1651

2114

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

2115

if(sd == -1){

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

2116

1654

ret_errno = errno;

2117

1655

perror_plus("socket");

2118

1656

errno = old_errno;

2119

1657

return ret_errno;

2120

1658

}

2121

1659

2122

1660

if(quit_now){

2123

ret = close(sd);

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

1661

close(sd);

2127

1662

errno = old_errno;

2128

1663

return EINTR;

2129

1664

}

2133

1668

interface);

2134

1669

}

2135

1670

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

1671

/* Raise priviliges */

1672

raise_privileges();

2142

1673

2143

1674

#ifdef __linux__

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

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

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

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");

2155

1682

}

2156

1683

#endif /* __linux__ */

2157

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

2158

ioctl_errno = errno;

1684

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

1685

ret_errno = errno;

2159

1686

#ifdef __linux__

2160

1687

if(restore_loglevel){

2161

1688

ret_linux = klogctl(7, NULL, 0);

2165

1692

}

2166

1693

#endif /* __linux__ */

2167

1694

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

1695

/* Lower privileges */

1696

lower_privileges();

2177

1697

2178

1698

/* Close the socket */

2179

ret = close(sd);

1699

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

2180

1700

if(ret == -1){

2181

1701

perror_plus("close");

2182

1702

}

2183

1703

2184

1704

if(ret_setflags == -1){

2185

errno = ioctl_errno;

1705

errno = ret_errno;

2186

1706

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2187

1707

errno = old_errno;

2188

return ioctl_errno;

1708

return ret_errno;

2189

1709

}

2190

1710

} else if(debug){

2191

1711

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

2209

1729

return 0;

2210

1730

}

2211

1731

2212

__attribute__((nonnull, warn_unused_result))

2213

int take_down_interface(const char *const interface){

2214

int old_errno = errno;

1732

error_t take_down_interface(const char *const interface){

1733

error_t old_errno = errno;

2215

1734

struct ifreq network;

2216

1735

unsigned int if_index = if_nametoindex(interface);

2217

1736

if(if_index == 0){

2220

1739

return ENXIO;

2221

1740

}

2222

1741

if(interface_is_up(interface)){

2223

int ret_errno = 0;

2224

int ioctl_errno = 0;

1742

error_t ret_errno = 0;

2225

1743

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

2226

1744

ret_errno = errno;

2227

1745

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

2228

1746

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

2229

errno = old_errno;

2230

1747

return ret_errno;

2231

1748

}

2232

1749

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

2233

1750

2234

1751

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

2235

if(sd == -1){

1752

if(sd < 0){

2236

1753

ret_errno = errno;

2237

1754

perror_plus("socket");

2238

1755

errno = old_errno;

2244

1761

interface);

2245

1762

}

2246

1763

2247

/* Raise privileges */

2248

ret_errno = raise_privileges();

2249

if(ret_errno != 0){

2250

errno = ret_errno;

2251

perror_plus("Failed to raise privileges");

2252

}

1764

/* Raise priviliges */

1765

raise_privileges();

2253

1766

2254

1767

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

2255

ioctl_errno = errno;

1768

ret_errno = errno;

2256

1769

2257

/* If raise_privileges() succeeded above */

2258

if(ret_errno == 0){

2259

/* Lower privileges */

2260

ret_errno = lower_privileges();

2261

if(ret_errno != 0){

2262

errno = ret_errno;

2263

perror_plus("Failed to lower privileges");

2264

}

2265

}

1770

/* Lower privileges */

1771

lower_privileges();

2266

1772

2267

1773

/* Close the socket */

2268

int ret = close(sd);

1774

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

2269

1775

if(ret == -1){

2270

1776

perror_plus("close");

2271

1777

}

2272

1778

2273

1779

if(ret_setflags == -1){

2274

errno = ioctl_errno;

1780

errno = ret_errno;

2275

1781

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2276

1782

errno = old_errno;

2277

return ioctl_errno;

1783

return ret_errno;

2278

1784

}

2279

1785

} else if(debug){

2280

1786

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

2286

1792

}

2287

1793

2288

1794

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

2289

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

2290

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

2291

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

2292

.current_server = NULL, .interfaces = NULL,

2293

.interfaces_size = 0 };

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 };

2294

1799

AvahiSServiceBrowser *sb = NULL;

2295

1800

error_t ret_errno;

2296

1801

int ret;

2299

1804

int exitcode = EXIT_SUCCESS;

2300

1805

char *interfaces_to_take_down = NULL;

2301

1806

size_t interfaces_to_take_down_size = 0;

2302

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

2303

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

2304

char *tempdir = NULL;

1807

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

1808

bool tempdir_created = false;

2305

1809

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2306

1810

const char *seckey = PATHDIR "/" SECKEY;

2307

1811

const char *pubkey = PATHDIR "/" PUBKEY;

2308

const char *dh_params_file = NULL;

2309

1812

char *interfaces_hooks = NULL;

2310

1813

2311

1814

bool gnutls_initialized = false;

2364

1867

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

2365

1868

" Diffie-Hellman key exchange",

2366

1869

.group = 2 },

2367

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

2368

.arg = "FILE",

2369

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

2370

" for the Diffie-Hellman key exchange",

2371

.group = 2 },

2372

1870

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

2373

1871

.arg = "STRING",

2374

1872

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

2429

1927

}

2430

1928

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

2431

1929

break;

2432

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

2433

dh_params_file = arg;

2434

break;

2435

1930

case 130: /* --priority */

2436

1931

mc.priority = arg;

2437

1932

break;

2477

1972

.args_doc = "",

2478

1973

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

2479

1974

" passwords from a Mandos server" };

2480

ret_errno = argp_parse(&argp, argc, argv,

2481

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2482

switch(ret_errno){

1975

ret = argp_parse(&argp, argc, argv,

1976

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1977

switch(ret){

2483

1978

case 0:

2484

1979

break;

2485

1980

case ENOMEM:

2486

1981

default:

2487

errno = ret_errno;

1982

errno = ret;

2488

1983

perror_plus("argp_parse");

2489

1984

exitcode = EX_OSERR;

2490

1985

goto end;

2493

1988

goto end;

2494

1989

}

2495

1990

}

2496

1991

2497

1992

{

2498

1993

/* Work around Debian bug #633582:

2499

1994

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

2500

1995

2501

/* Re-raise privileges */

2502

ret = raise_privileges();

2503

if(ret != 0){

2504

errno = ret;

2505

perror_plus("Failed to raise privileges");

2506

} else {

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2507

1998

struct stat st;

2508

1999

2509

2000

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

2523

2014

}

2524

2015

}

2525

2016

}

2526

close(seckey_fd);

2017

TEMP_FAILURE_RETRY(close(seckey_fd));

2527

2018

}

2528

2019

}

2529

2020

2530

2021

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

2531

2022

int pubkey_fd = open(pubkey, O_RDONLY);

2532

2023

if(pubkey_fd == -1){

2544

2035

}

2545

2036

}

2546

2037

}

2547

close(pubkey_fd);

2548

}

2549

}

2550

2551

if(dh_params_file != NULL

2552

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

2553

int dhparams_fd = open(dh_params_file, O_RDONLY);

2554

if(dhparams_fd == -1){

2555

perror_plus("open");

2556

} else {

2557

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

2558

if(ret == -1){

2559

perror_plus("fstat");

2560

} else {

2561

if(S_ISREG(st.st_mode)

2562

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

2563

ret = fchown(dhparams_fd, uid, gid);

2564

if(ret == -1){

2565

perror_plus("fchown");

2566

}

2567

}

2568

}

2569

close(dhparams_fd);

2570

}

2571

}

2572

2038

TEMP_FAILURE_RETRY(close(pubkey_fd));

2039

}

2040

}

2041

2573

2042

/* Lower privileges */

2574

ret = lower_privileges();

2575

if(ret != 0){

2576

errno = ret;

2577

perror_plus("Failed to lower privileges");

2578

}

2043

lower_privileges();

2579

2044

}

2580

2045

}

2581

2046

2607

2072

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

2608

2073

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

2609

2074

}

2610

run_network_hooks("start", interfaces_hooks != NULL ?

2611

interfaces_hooks : "", delay);

2075

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

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2612

2079

}

2613

2080

2614

2081

if(not debug){

2692

2159

2693

2160

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

2694

2161

if(mc.interfaces == NULL){

2695

struct dirent **direntries = NULL;

2162

struct dirent **direntries;

2696

2163

/* Look for any good interfaces */

2697

2164

ret = scandir(sys_class_net, &direntries, good_interface,

2698

2165

alphasort);

2704

2171

if(ret_errno != 0){

2705

2172

errno = ret_errno;

2706

2173

perror_plus("argz_add");

2707

free(direntries[i]);

2708

2174

continue;

2709

2175

}

2710

2176

if(debug){

2711

2177

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

2712

2178

direntries[i]->d_name);

2713

2179

}

2714

free(direntries[i]);

2715

2180

}

2716

2181

free(direntries);

2717

2182

} else {

2718

if(ret == 0){

2719

free(direntries);

2720

}

2183

free(direntries);

2721

2184

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

2722

2185

exitcode = EXIT_FAILURE;

2723

2186

goto end;

2746

2209

break;

2747

2210

}

2748

2211

bool interface_was_up = interface_is_up(interface);

2749

errno = bring_up_interface(interface, delay);

2212

ret = bring_up_interface(interface, delay);

2750

2213

if(not interface_was_up){

2751

if(errno != 0){

2752

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

2753

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

2214

if(ret != 0){

2215

errno = ret;

2216

perror_plus("Failed to bring up interface");

2754

2217

} else {

2755

errno = argz_add(&interfaces_to_take_down,

2756

&interfaces_to_take_down_size,

2757

interface);

2758

if(errno != 0){

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;

2759

2223

perror_plus("argz_add");

2760

2224

}

2761

2225

}

2779

2243

goto end;

2780

2244

}

2781

2245

2782

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

2246

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

2783

2247

if(ret == -1){

2784

2248

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

2785

2249

exitcode = EX_UNAVAILABLE;

2792

2256

goto end;

2793

2257

}

2794

2258

2795

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

2796

tempdir = mkdtemp(run_tempdir);

2797

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

2798

if(debug){

2799

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

2800

run_tempdir, old_tempdir);

2801

}

2802

tempdir = mkdtemp(old_tempdir);

2803

}

2804

if(tempdir == NULL){

2259

if(mkdtemp(tempdir) == NULL){

2805

2260

perror_plus("mkdtemp");

2806

2261

goto end;

2807

2262

}

2263

tempdir_created = true;

2808

2264

2809

2265

if(quit_now){

2810

2266

goto end;

2885

2341

sleep((unsigned int)retry_interval);

2886

2342

}

2887

2343

2888

if(not quit_now){

2344

if (not quit_now){

2889

2345

exitcode = EXIT_SUCCESS;

2890

2346

}

2891

2347

2907

2363

2908

2364

/* Allocate a new server */

2909

2365

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2910

&config, NULL, NULL, &ret);

2366

&config, NULL, NULL, &ret_errno);

2911

2367

2912

2368

/* Free the Avahi configuration data */

2913

2369

avahi_server_config_free(&config);

2916

2372

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

2917

2373

if(mc.server == NULL){

2918

2374

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

2919

avahi_strerror(ret));

2375

avahi_strerror(ret_errno));

2920

2376

exitcode = EX_UNAVAILABLE;

2921

2377

goto end;

2922

2378

}

2946

2402

if(debug){

2947

2403

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

2948

2404

}

2949

2405

2950

2406

ret = avahi_loop_with_timeout(simple_poll,

2951

2407

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

2952

2408

if(debug){

2974

2430

2975

2431

if(gnutls_initialized){

2976

2432

gnutls_certificate_free_credentials(mc.cred);

2433

gnutls_global_deinit();

2977

2434

gnutls_dh_params_deinit(mc.dh_params);

2978

2435

}

2979

2436

2987

2444

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

2988

2445

while(mc.current_server != NULL){

2989

2446

server *next = mc.current_server->next;

2990

#ifdef __GNUC__

2991

#pragma GCC diagnostic push

2992

#pragma GCC diagnostic ignored "-Wcast-qual"

2993

#endif

2994

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

2995

#ifdef __GNUC__

2996

#pragma GCC diagnostic pop

2997

#endif

2998

2447

free(mc.current_server);

2999

2448

mc.current_server = next;

3000

2449

}

3001

2450

}

3002

2451

3003

/* Re-raise privileges */

2452

/* Re-raise priviliges */

3004

2453

{

3005

ret = raise_privileges();

3006

if(ret != 0){

3007

errno = ret;

3008

perror_plus("Failed to raise privileges");

3009

} else {

3010

3011

/* Run network hooks */

3012

run_network_hooks("stop", interfaces_hooks != NULL ?

3013

interfaces_hooks : "", delay);

3014

3015

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

3016

{

3017

char *interface = NULL;

3018

while((interface=argz_next(interfaces_to_take_down,

3019

interfaces_to_take_down_size,

3020

interface))){

3021

ret = take_down_interface(interface);

3022

if(ret != 0){

3023

errno = ret;

3024

perror_plus("Failed to take down interface");

3025

}

3026

}

3027

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

3028

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

3029

" down\n");

3030

}

3031

}

3032

}

3033

3034

ret = lower_privileges_permanently();

3035

if(ret != 0){

3036

errno = ret;

3037

perror_plus("Failed to lower privileges permanently");

3038

}

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();

3039

2479

}

3040

2480

3041

2481

free(interfaces_to_take_down);

3042

2482

free(interfaces_hooks);

3043

2483

3044

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

3045

uintmax_t level){

2484

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

2485

if(tempdir_created){

3046

2486

struct dirent **direntries = NULL;

3047

int dret;

3048

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

3049

O_RDONLY

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(dir_fd == -1){

3054

perror_plus("open");

3055

}

3056

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

3057

notdotentries, alphasort);

3058

if(numentries >= 0){

2487

struct dirent *direntry = NULL;

2488

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

2489

alphasort);

2490

if (numentries > 0){

3059

2491

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

3060

if(debug){

3061

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

3062

dirname, direntries[i]->d_name);

3063

}

3064

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

3065

if(dret == -1){

3066

if(errno == EISDIR){

3067

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

3068

AT_REMOVEDIR);

3069

}

3070

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

3071

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

3072

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

3073

/* Recurse only in this special case */

3074

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

3075

dret = 0;

3076

}

3077

if(dret == -1){

3078

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

3079

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

3080

}

3081

}

3082

free(direntries[i]);

3083

}

3084

3085

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

3086

free(direntries);

3087

if(numentries == -1){

3088

perror_plus("scandirat");

3089

}

3090

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3091

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

3092

perror_plus("rmdir");

3093

}

3094

} else {

3095

perror_plus("scandirat");

3096

}

3097

close(dir_fd);

3098

}

3099

3100

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

3101

if(tempdir != NULL){

3102

clean_dir_at(-1, tempdir, 0);

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

}

3103

2518

}

3104

2519

3105

2520

if(quit_now){