/mandos/release : revision 237.7.360

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() */

51

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

52

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

53

sockaddr_in6, PF_INET6,

55

opendir(), DIR */

56

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

57

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

58

inet_pton(), connect() */

59

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

72

73

*/

73

74

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

74

75

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

75

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

76

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

76

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

77

unlinkat() */

78

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

77

79

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

78

80

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

79

81

argp_state, struct argp,

91

93

argz_delete(), argz_append(),

92

94

argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

141

146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

180

185

perror(print_text);

181

186

}

182

187

183

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

188

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

184

189

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

185

190

va_list ap;

186

191

va_start (ap, format);

187

192

188

193

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

189

194

program_invocation_short_name));

190

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

195

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

191

196

}

192

197

193

198

/*

195

200

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

196

201

* "buffer_length" is how much is already used.

197

202

*/

203

__attribute__((nonnull, warn_unused_result))

198

204

size_t incbuffer(char **buffer, size_t buffer_length,

199

205

size_t buffer_capacity){

200

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

201

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

202

if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

203

213

return 0;

204

214

}

215

*buffer = new_buf;

205

216

buffer_capacity += BUFFER_SIZE;

206

217

}

207

218

return buffer_capacity;

208

219

}

209

220

210

221

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

222

__attribute__((nonnull, warn_unused_result))

211

223

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

212

224

int af, server **current_server){

213

225

int ret;

222

234

.af = af };

223

235

if(new_server->ip == NULL){

224

236

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

225

252

return false;

226

253

}

227

254

/* Special case of first server */

229

256

new_server->next = new_server;

230

257

new_server->prev = new_server;

231

258

*current_server = new_server;

232

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

233

259

} else {

260

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

234

261

new_server->next = *current_server;

235

262

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

236

263

new_server->prev->next = new_server;

237

264

(*current_server)->prev = new_server;

238

265

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

244

266

return true;

245

267

}

246

268

247

269

/*

248

270

* Initialize GPGME.

249

271

*/

250

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

251

const char *tempdir, mandos_context *mc){

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

252

277

gpgme_error_t rc;

253

278

gpgme_engine_info_t engine_info;

254

279

255

280

/*

256

281

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

257

282

*/

258

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

259

284

int ret;

260

285

int fd;

261

286

gpgme_data_t pgp_data;

280

305

return false;

281

306

}

282

307

283

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

308

ret = close(fd);

284

309

if(ret == -1){

285

310

perror_plus("close");

286

311

}

342

367

* Decrypt OpenPGP data.

343

368

* Returns -1 on error

344

369

*/

370

__attribute__((nonnull, warn_unused_result))

345

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

346

372

size_t crypto_size,

347

373

char **plaintext,

467

493

return plaintext_length;

468

494

}

469

495

470

static const char * safer_gnutls_strerror(int value){

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

471

505

const char *ret = gnutls_strerror(value);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

506

return safe_string(ret);

475

507

}

476

508

477

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

478

511

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

479

512

const char* string){

480

513

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

481

514

}

482

515

516

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

483

517

static int init_gnutls_global(const char *pubkeyfilename,

484

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

485

520

mandos_context *mc){

486

521

int ret;

522

unsigned int uret;

487

523

488

524

if(debug){

489

525

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

490

526

}

491

527

492

ret = gnutls_global_init();

493

if(ret != GNUTLS_E_SUCCESS){

494

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

495

safer_gnutls_strerror(ret));

496

return -1;

497

}

498

499

528

if(debug){

500

529

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

501

530

* - GnuTLS manual

509

538

if(ret != GNUTLS_E_SUCCESS){

510

539

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

511

540

safer_gnutls_strerror(ret));

512

gnutls_global_deinit();

513

541

return -1;

514

542

}

515

543

540

568

safer_gnutls_strerror(ret));

541

569

goto globalfail;

542

570

}

543

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

544

if(ret != GNUTLS_E_SUCCESS){

545

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

546

safer_gnutls_strerror(ret));

547

goto globalfail;

548

}

549

571

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

572

if(dhparamsfilename != NULL){

573

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

574

do {

575

int dhpfile = open(dhparamsfilename, O_RDONLY);

576

if(dhpfile == -1){

577

perror_plus("open");

578

dhparamsfilename = NULL;

579

break;

580

}

581

size_t params_capacity = 0;

582

while(true){

583

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

584

(size_t)params.size,

585

(size_t)params_capacity);

586

if(params_capacity == 0){

587

perror_plus("incbuffer");

588

free(params.data);

589

params.data = NULL;

590

dhparamsfilename = NULL;

591

break;

592

}

593

ssize_t bytes_read = read(dhpfile,

594

params.data + params.size,

595

BUFFER_SIZE);

596

/* EOF */

597

if(bytes_read == 0){

598

break;

599

}

600

/* check bytes_read for failure */

601

if(bytes_read < 0){

602

perror_plus("read");

603

free(params.data);

604

params.data = NULL;

605

dhparamsfilename = NULL;

606

break;

607

}

608

params.size += (unsigned int)bytes_read;

609

}

610

if(params.data == NULL){

611

dhparamsfilename = NULL;

612

}

613

if(dhparamsfilename == NULL){

614

break;

615

}

616

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

617

GNUTLS_X509_FMT_PEM);

618

if(ret != GNUTLS_E_SUCCESS){

619

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

620

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

621

safer_gnutls_strerror(ret));

622

dhparamsfilename = NULL;

623

}

624

} while(false);

625

}

626

if(dhparamsfilename == NULL){

627

if(mc->dh_bits == 0){

628

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

629

/* Try to read the private key file */

630

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

631

do {

632

int secfile = open(seckeyfilename, O_RDONLY);

633

if(secfile == -1){

634

perror_plus("open");

635

break;

636

}

637

size_t buffer_capacity = 0;

638

while(true){

639

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

640

(size_t)buffer.size,

641

(size_t)buffer_capacity);

642

if(buffer_capacity == 0){

643

perror_plus("incbuffer");

644

free(buffer.data);

645

buffer.data = NULL;

646

break;

647

}

648

ssize_t bytes_read = read(secfile,

649

buffer.data + buffer.size,

650

BUFFER_SIZE);

651

/* EOF */

652

if(bytes_read == 0){

653

break;

654

}

655

/* check bytes_read for failure */

656

if(bytes_read < 0){

657

perror_plus("read");

658

free(buffer.data);

659

buffer.data = NULL;

660

break;

661

}

662

buffer.size += (unsigned int)bytes_read;

663

}

664

close(secfile);

665

} while(false);

666

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

667

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

668

if(buffer.data != NULL){

669

{

670

gnutls_openpgp_privkey_t privkey = NULL;

671

ret = gnutls_openpgp_privkey_init(&privkey);

672

if(ret != GNUTLS_E_SUCCESS){

673

fprintf_plus(stderr, "Error initializing OpenPGP key"

674

" structure: %s",

675

safer_gnutls_strerror(ret));

676

free(buffer.data);

677

buffer.data = NULL;

678

} else {

679

ret = gnutls_openpgp_privkey_import

680

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

681

if(ret != GNUTLS_E_SUCCESS){

682

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

683

safer_gnutls_strerror(ret));

684

privkey = NULL;

685

}

686

free(buffer.data);

687

buffer.data = NULL;

688

if(privkey != NULL){

689

/* Use private key to suggest an appropriate

690

sec_param */

691

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

692

gnutls_openpgp_privkey_deinit(privkey);

693

if(debug){

694

fprintf_plus(stderr, "This OpenPGP key implies using"

695

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

696

safe_string(gnutls_sec_param_get_name

697

(sec_param)));

698

}

699

}

700

}

701

}

702

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

703

/* Err on the side of caution */

704

sec_param = GNUTLS_SEC_PARAM_ULTRA;

705

if(debug){

706

fprintf_plus(stderr, "Falling back to security parameter"

707

" \"%s\"\n",

708

safe_string(gnutls_sec_param_get_name

709

(sec_param)));

710

}

711

}

712

}

713

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

714

if(uret != 0){

715

mc->dh_bits = uret;

716

if(debug){

717

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

718

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

719

safe_string(gnutls_sec_param_get_name

720

(sec_param)),

721

mc->dh_bits);

722

}

723

} else {

724

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

725

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

726

safe_string(gnutls_sec_param_get_name

727

(sec_param)),

728

safer_gnutls_strerror(ret));

729

goto globalfail;

730

}

731

} else if(debug){

732

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

733

mc->dh_bits);

734

}

735

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

736

if(ret != GNUTLS_E_SUCCESS){

737

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

738

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

739

safer_gnutls_strerror(ret));

740

goto globalfail;

741

}

742

}

550

743

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

551

744

552

745

return 0;

554

747

globalfail:

555

748

556

749

gnutls_certificate_free_credentials(mc->cred);

557

gnutls_global_deinit();

558

750

gnutls_dh_params_deinit(mc->dh_params);

559

751

return -1;

560

752

}

561

753

754

__attribute__((nonnull, warn_unused_result))

562

755

static int init_gnutls_session(gnutls_session_t *session,

563

756

mandos_context *mc){

564

757

int ret;

611

804

/* ignore client certificate if any. */

612

805

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

806

614

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

616

807

return 0;

617

808

}

618

809

620

811

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

621

812

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

622

813

814

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

815

__attribute__((warn_unused_result))

816

error_t raise_privileges(void){

817

error_t old_errno = errno;

818

error_t ret_errno = 0;

819

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

820

ret_errno = errno;

821

}

822

errno = old_errno;

823

return ret_errno;

824

}

825

826

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

827

__attribute__((warn_unused_result))

828

error_t raise_privileges_permanently(void){

829

error_t old_errno = errno;

830

error_t ret_errno = raise_privileges();

831

if(ret_errno != 0){

832

errno = old_errno;

833

return ret_errno;

834

}

835

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

836

ret_errno = errno;

837

}

838

errno = old_errno;

839

return ret_errno;

840

}

841

842

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

843

__attribute__((warn_unused_result))

844

error_t lower_privileges(void){

845

error_t old_errno = errno;

846

error_t ret_errno = 0;

847

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

848

ret_errno = errno;

849

}

850

errno = old_errno;

851

return ret_errno;

852

}

853

854

/* Lower privileges permanently */

855

__attribute__((warn_unused_result))

856

error_t lower_privileges_permanently(void){

857

error_t old_errno = errno;

858

error_t ret_errno = 0;

859

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

860

ret_errno = errno;

861

}

862

errno = old_errno;

863

return ret_errno;

864

}

865

866

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

867

__attribute__((nonnull, warn_unused_result))

868

static bool add_delete_local_route(const bool add,

869

const char *address,

870

AvahiIfIndex if_index){

871

int ret;

872

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

873

char add_arg[] = "add";

874

char delete_arg[] = "delete";

875

char debug_flag[] = "--debug";

876

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

877

if(pluginhelperdir == NULL){

878

if(debug){

879

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

880

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

881

}

882

return false;

883

}

884

885

char interface[IF_NAMESIZE];

886

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

887

perror_plus("if_indextoname");

888

return false;

889

}

890

891

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

892

if(devnull == -1){

893

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

894

return false;

895

}

896

pid_t pid = fork();

897

if(pid == 0){

898

/* Child */

899

/* Raise privileges */

900

errno = raise_privileges_permanently();

901

if(errno != 0){

902

perror_plus("Failed to raise privileges");

903

/* _exit(EX_NOPERM); */

904

} else {

905

/* Set group */

906

errno = 0;

907

ret = setgid(0);

908

if(ret == -1){

909

perror_plus("setgid");

910

_exit(EX_NOPERM);

911

}

912

/* Reset supplementary groups */

913

errno = 0;

914

ret = setgroups(0, NULL);

915

if(ret == -1){

916

perror_plus("setgroups");

917

_exit(EX_NOPERM);

918

}

919

}

920

ret = dup2(devnull, STDIN_FILENO);

921

if(ret == -1){

922

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

923

_exit(EX_OSERR);

924

}

925

ret = close(devnull);

926

if(ret == -1){

927

perror_plus("close");

928

_exit(EX_OSERR);

929

}

930

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

931

if(ret == -1){

932

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

933

_exit(EX_OSERR);

934

}

935

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

936

O_RDONLY

937

| O_DIRECTORY

938

| O_PATH

939

| O_CLOEXEC));

940

if(helperdir_fd == -1){

941

perror_plus("open");

942

_exit(EX_UNAVAILABLE);

943

}

944

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

945

helper, O_RDONLY));

946

if(helper_fd == -1){

947

perror_plus("openat");

948

close(helperdir_fd);

949

_exit(EX_UNAVAILABLE);

950

}

951

close(helperdir_fd);

952

#ifdef __GNUC__

953

#pragma GCC diagnostic push

954

#pragma GCC diagnostic ignored "-Wcast-qual"

955

#endif

956

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

957

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

958

interface, debug ? debug_flag : NULL, NULL },

959

environ) == -1){

960

#ifdef __GNUC__

961

#pragma GCC diagnostic pop

962

#endif

963

perror_plus("fexecve");

964

_exit(EXIT_FAILURE);

965

}

966

}

967

if(pid == -1){

968

perror_plus("fork");

969

return false;

970

}

971

int status;

972

pid_t pret = -1;

973

errno = 0;

974

do {

975

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

976

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

977

int errno_raising = 0;

978

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

979

errno_raising = errno;

980

perror_plus("Failed to raise privileges in order to"

981

" kill helper program");

982

}

983

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

984

perror_plus("kill");

985

}

986

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

987

perror_plus("Failed to lower privileges after killing"

988

" helper program");

989

}

990

return false;

991

}

992

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

993

if(pret == -1){

994

perror_plus("waitpid");

995

return false;

996

}

997

if(WIFEXITED(status)){

998

if(WEXITSTATUS(status) != 0){

999

fprintf_plus(stderr, "Error: iprouteadddel exited"

1000

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

1001

return false;

1002

}

1003

return true;

1004

}

1005

if(WIFSIGNALED(status)){

1006

fprintf_plus(stderr, "Error: iprouteadddel died by"

1007

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

1008

return false;

1009

}

1010

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

1011

return false;

1012

}

1013

1014

__attribute__((nonnull, warn_unused_result))

1015

static bool add_local_route(const char *address,

1016

AvahiIfIndex if_index){

1017

if(debug){

1018

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

1019

}

1020

return add_delete_local_route(true, address, if_index);

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool delete_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(false, address, if_index);

1030

}

1031

623

1032

/* Called when a Mandos server is found */

1033

__attribute__((nonnull, warn_unused_result))

624

1034

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

625

1035

AvahiIfIndex if_index,

626

1036

int af, mandos_context *mc){

627

1037

int ret, tcp_sd = -1;

628

1038

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1039

struct sockaddr_storage to;

633

1040

char *buffer = NULL;

634

1041

char *decrypted_buffer = NULL;

635

1042

size_t buffer_length = 0;

638

1045

int retval = -1;

639

1046

gnutls_session_t session;

640

1047

int pf; /* Protocol family */

1048

bool route_added = false;

641

1049

642

1050

errno = 0;

643

1051

701

1109

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

702

1110

}

703

1111

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1112

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

705

1113

if(tcp_sd < 0){

706

1114

int e = errno;

707

1115

perror_plus("socket");

714

1122

goto mandos_end;

715

1123

}

716

1124

717

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

718

1125

if(af == AF_INET6){

719

to.in6.sin6_family = (sa_family_t)af;

720

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

1126

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

1127

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

1128

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

721

1129

} else { /* IPv4 */

722

to.in.sin_family = (sa_family_t)af;

723

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

1130

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

1131

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

1132

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

724

1133

}

725

1134

if(ret < 0 ){

726

1135

int e = errno;

735

1144

goto mandos_end;

736

1145

}

737

1146

if(af == AF_INET6){

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

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

741

-Wunreachable-code*/

1147

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

1148

if(IN6_IS_ADDR_LINKLOCAL

1149

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

742

1150

if(if_index == AVAHI_IF_UNSPEC){

743

1151

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

744

1152

" incomplete without a network interface\n");

746

1154

goto mandos_end;

747

1155

}

748

1156

/* Set the network interface number as scope */

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1157

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

750

1158

}

751

1159

} else {

752

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

753

-Wconversion and

754

-Wunreachable-code */

1160

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

755

1161

}

756

1162

757

1163

if(quit_now){

774

1180

}

775

1181

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

776

1182

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

777

const char *pcret;

778

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

781

} else {

782

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

783

sizeof(addrstr));

784

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

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

789

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

790

}

791

}

792

}

793

794

if(quit_now){

795

errno = EINTR;

796

goto mandos_end;

797

}

798

799

if(af == AF_INET6){

800

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

801

} else {

802

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

803

}

804

if(ret < 0){

805

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

806

int e = errno;

807

perror_plus("connect");

808

errno = e;

809

}

810

goto mandos_end;

811

}

812

813

if(quit_now){

814

errno = EINTR;

815

goto mandos_end;

1183

if(af == AF_INET6){

1184

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

1185

sizeof(struct sockaddr_in6),

1186

addrstr, sizeof(addrstr), NULL, 0,

1187

NI_NUMERICHOST);

1188

} else {

1189

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

1190

sizeof(struct sockaddr_in),

1191

addrstr, sizeof(addrstr), NULL, 0,

1192

NI_NUMERICHOST);

1193

}

1194

if(ret == EAI_SYSTEM){

1195

perror_plus("getnameinfo");

1196

} else if(ret != 0) {

1197

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

1198

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

1199

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

1200

}

1201

}

1202

1203

if(quit_now){

1204

errno = EINTR;

1205

goto mandos_end;

1206

}

1207

1208

while(true){

1209

if(af == AF_INET6){

1210

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

1211

sizeof(struct sockaddr_in6));

1212

} else {

1213

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

1214

sizeof(struct sockaddr_in));

1215

}

1216

if(ret < 0){

1217

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

1218

and if_index != AVAHI_IF_UNSPEC

1219

and connect_to == NULL

1220

and not route_added and

1221

((af == AF_INET6 and not

1222

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1223

&to)->sin6_addr)))

1224

or (af == AF_INET and

1225

/* Not a a IPv4LL address */

1226

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

1227

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

1228

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

1229

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

1230

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

1231

connect to a Mandos server announced by Avahi on a server

1232

host with a global address. Work around this by retrying

1233

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

1234

1235

Avahi bug reference:

1236

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

1237

https://bugs.debian.org/587961

1238

*/

1239

if(debug){

1240

fprintf_plus(stderr, "Mandos server unreachable, trying"

1241

" direct route\n");

1242

}

1243

int e = errno;

1244

route_added = add_local_route(ip, if_index);

1245

if(route_added){

1246

continue;

1247

}

1248

errno = e;

1249

}

1250

if(errno != ECONNREFUSED or debug){

1251

int e = errno;

1252

perror_plus("connect");

1253

errno = e;

1254

}

1255

goto mandos_end;

1256

}

1257

1258

if(quit_now){

1259

errno = EINTR;

1260

goto mandos_end;

1261

}

1262

break;

816

1263

}

817

1264

818

1265

const char *out = mandos_protocol_version;

1001

1448

1002

1449

mandos_end:

1003

1450

{

1451

if(route_added){

1452

if(not delete_local_route(ip, if_index)){

1453

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

1454

" interface %d", ip, if_index);

1455

}

1456

}

1004

1457

int e = errno;

1005

1458

free(decrypted_buffer);

1006

1459

free(buffer);

1007

1460

if(tcp_sd >= 0){

1008

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

1461

ret = close(tcp_sd);

1009

1462

}

1010

1463

if(ret == -1){

1011

1464

if(e == 0){

1023

1476

return retval;

1024

1477

}

1025

1478

1479

__attribute__((nonnull))

1026

1480

static void resolve_callback(AvahiSServiceResolver *r,

1027

1481

AvahiIfIndex interface,

1028

1482

AvahiProtocol proto,

1036

1490

AVAHI_GCC_UNUSED AvahiStringList *txt,

1037

1491

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1038

1492

flags,

1039

void* mc){

1493

void *mc){

1040

1494

if(r == NULL){

1041

1495

return;

1042

1496

}

1045

1499

timed out */

1046

1500

1047

1501

if(quit_now){

1502

avahi_s_service_resolver_free(r);

1048

1503

return;

1049

1504

}

1050

1505

1095

1550

const char *domain,

1096

1551

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1097

1552

flags,

1098

void* mc){

1553

void *mc){

1099

1554

if(b == NULL){

1100

1555

return;

1101

1556

}

1161

1616

errno = old_errno;

1162

1617

}

1163

1618

1619

__attribute__((nonnull, warn_unused_result))

1164

1620

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

1165

1621

int ret;

1166

1622

error_t ret_errno;

1172

1628

errno = ret_errno;

1173

1629

return false;

1174

1630

}

1175

strcpy(ifr->ifr_name, ifname);

1631

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

1632

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

1176

1633

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1177

1634

if(ret == -1){

1178

1635

if(debug){

1185

1642

return true;

1186

1643

}

1187

1644

1645

__attribute__((nonnull, warn_unused_result))

1188

1646

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

1189

1647

1190

1648

/* Reject the loopback device */

1232

1690

* corresponds to an acceptable network device.

1233

1691

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

1234

1692

*/

1693

__attribute__((nonnull, warn_unused_result))

1235

1694

int good_interface(const struct dirent *if_entry){

1236

1695

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

1237

1696

return 0;

1255

1714

/*

1256

1715

* This function determines if a network interface is up.

1257

1716

*/

1717

__attribute__((nonnull, warn_unused_result))

1258

1718

bool interface_is_up(const char *interface){

1259

1719

struct ifreq ifr;

1260

1720

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

1271

1731

/*

1272

1732

* This function determines if a network interface is running

1273

1733

*/

1734

__attribute__((nonnull, warn_unused_result))

1274

1735

bool interface_is_running(const char *interface){

1275

1736

struct ifreq ifr;

1276

1737

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

1284

1745

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

1285

1746

}

1286

1747

1748

__attribute__((nonnull, pure, warn_unused_result))

1287

1749

int notdotentries(const struct dirent *direntry){

1288

1750

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

1289

1751

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

1296

1758

}

1297

1759

1298

1760

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

1761

__attribute__((nonnull, warn_unused_result))

1299

1762

int runnable_hook(const struct dirent *direntry){

1300

1763

int ret;

1301

1764

size_t sret;

1309

1772

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

1310

1773

"abcdefghijklmnopqrstuvwxyz"

1311

1774

"0123456789"

1312

"_-");

1775

"_.-");

1313

1776

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

1314

1777

/* Contains non-allowed characters */

1315

1778

if(debug){

1319

1782

return 0;

1320

1783

}

1321

1784

1322

char *fullname = NULL;

1323

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

1324

if(ret < 0){

1325

perror_plus("asprintf");

1326

return 0;

1327

}

1328

1329

ret = stat(fullname, &st);

1785

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

1330

1786

if(ret == -1){

1331

1787

if(debug){

1332

1788

perror_plus("Could not stat hook");

1356

1812

return 1;

1357

1813

}

1358

1814

1815

__attribute__((nonnull, warn_unused_result))

1359

1816

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1360

1817

mandos_context *mc){

1361

1818

int ret;

1365

1822

1366

1823

while(true){

1367

1824

if(mc->current_server == NULL){

1368

if (debug){

1825

if(debug){

1369

1826

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

1370

1827

" No timeout!\n");

1371

1828

}

1372

1829

ret = avahi_simple_poll_iterate(s, -1);

1373

1830

} else {

1374

if (debug){

1831

if(debug){

1375

1832

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

1376

1833

" it, or wait\n");

1377

1834

}

1394

1851

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

1395

1852

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

1396

1853

1397

if (debug){

1854

if(debug){

1398

1855

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

1399

1856

block_time);

1400

1857

}

1422

1879

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

1423

1880

}

1424

1881

if(ret != 0){

1425

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

1882

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

1426

1883

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

1427

1884

}

1428

1885

}

1429

1886

}

1430

1887

}

1431

1888

1432

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

1433

error_t raise_privileges(void){

1434

error_t old_errno = errno;

1435

error_t ret_errno = 0;

1436

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

1437

ret_errno = errno;

1438

perror_plus("seteuid");

1439

}

1440

errno = old_errno;

1441

return ret_errno;

1442

}

1443

1444

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

1445

error_t raise_privileges_permanently(void){

1446

error_t old_errno = errno;

1447

error_t ret_errno = raise_privileges();

1448

if(ret_errno != 0){

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

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

1453

ret_errno = errno;

1454

perror_plus("seteuid");

1455

}

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

1460

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

1461

error_t lower_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

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

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

/* Lower privileges permanently */

1473

error_t lower_privileges_permanently(void){

1474

error_t old_errno = errno;

1475

error_t ret_errno = 0;

1476

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

1477

ret_errno = errno;

1478

perror_plus("setuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

1889

__attribute__((nonnull))

1890

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

1485

1891

const float delay){

1486

struct dirent **direntries;

1892

struct dirent **direntries = NULL;

1893

if(hookdir_fd == -1){

1894

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1895

| O_CLOEXEC);

1896

if(hookdir_fd == -1){

1897

if(errno == ENOENT){

1898

if(debug){

1899

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

1900

" found\n", hookdir);

1901

}

1902

} else {

1903

perror_plus("open");

1904

}

1905

return;

1906

}

1907

}

1908

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

1909

runnable_hook, alphasort);

1910

if(numhooks == -1){

1911

perror_plus("scandir");

1912

return;

1913

}

1487

1914

struct dirent *direntry;

1488

1915

int ret;

1489

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

1490

alphasort);

1491

if(numhooks == -1){

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

perror_plus("scandir");

1916

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

1917

if(devnull == -1){

1918

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

1919

return;

1920

}

1921

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

1922

direntry = direntries[i];

1923

if(debug){

1924

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

1925

direntry->d_name);

1499

1926

}

1500

} else {

1501

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

1502

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

1503

direntry = direntries[i];

1504

char *fullname = NULL;

1505

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

1506

if(ret < 0){

1927

pid_t hook_pid = fork();

1928

if(hook_pid == 0){

1929

/* Child */

1930

/* Raise privileges */

1931

errno = raise_privileges_permanently();

1932

if(errno != 0){

1933

perror_plus("Failed to raise privileges");

1934

_exit(EX_NOPERM);

1935

}

1936

/* Set group */

1937

errno = 0;

1938

ret = setgid(0);

1939

if(ret == -1){

1940

perror_plus("setgid");

1941

_exit(EX_NOPERM);

1942

}

1943

/* Reset supplementary groups */

1944

errno = 0;

1945

ret = setgroups(0, NULL);

1946

if(ret == -1){

1947

perror_plus("setgroups");

1948

_exit(EX_NOPERM);

1949

}

1950

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

1951

if(ret == -1){

1952

perror_plus("setenv");

1953

_exit(EX_OSERR);

1954

}

1955

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

1956

if(ret == -1){

1957

perror_plus("setenv");

1958

_exit(EX_OSERR);

1959

}

1960

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

1961

if(ret == -1){

1962

perror_plus("setenv");

1963

_exit(EX_OSERR);

1964

}

1965

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

1966

if(ret == -1){

1967

perror_plus("setenv");

1968

_exit(EX_OSERR);

1969

}

1970

char *delaystring;

1971

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

1972

if(ret == -1){

1507

1973

perror_plus("asprintf");

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

1974

_exit(EX_OSERR);

1975

}

1976

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

1977

if(ret == -1){

1566

1978

free(delaystring);

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

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

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

1979

perror_plus("setenv");

1980

_exit(EX_OSERR);

1981

}

1982

free(delaystring);

1983

if(connect_to != NULL){

1984

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

1985

if(ret == -1){

1986

perror_plus("setenv");

1987

_exit(EX_OSERR);

1988

}

1989

}

1990

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

1991

direntry->d_name,

1992

O_RDONLY));

1993

if(hook_fd == -1){

1994

perror_plus("openat");

1995

_exit(EXIT_FAILURE);

1996

}

1997

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

1998

perror_plus("close");

1999

_exit(EXIT_FAILURE);

2000

}

2001

ret = dup2(devnull, STDIN_FILENO);

2002

if(ret == -1){

2003

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

2004

_exit(EX_OSERR);

2005

}

2006

ret = close(devnull);

2007

if(ret == -1){

2008

perror_plus("close");

2009

_exit(EX_OSERR);

2010

}

2011

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2012

if(ret == -1){

2013

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

2014

_exit(EX_OSERR);

2015

}

2016

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

2017

environ) == -1){

2018

perror_plus("fexecve");

2019

_exit(EXIT_FAILURE);

2020

}

2021

} else {

2022

if(hook_pid == -1){

2023

perror_plus("fork");

2024

free(direntry);

2025

continue;

2026

}

2027

int status;

2028

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

2029

perror_plus("waitpid");

2030

free(direntry);

2031

continue;

2032

}

2033

if(WIFEXITED(status)){

2034

if(WEXITSTATUS(status) != 0){

2035

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

2036

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

2037

WEXITSTATUS(status));

2038

free(direntry);

2039

continue;

2040

}

2041

} else if(WIFSIGNALED(status)){

2042

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

2043

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

2044

WTERMSIG(status));

2045

free(direntry);

2046

continue;

1578

2047

} else {

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

return true;

2048

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

2049

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

2050

free(direntry);

2051

continue;

2052

}

2053

}

2054

if(debug){

2055

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

2056

direntry->d_name);

2057

}

2058

free(direntry);

2059

}

2060

free(direntries);

2061

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

2062

perror_plus("close");

2063

} else {

2064

hookdir_fd = -1;

2065

}

2066

close(devnull);

1615

2067

}

1616

2068

2069

__attribute__((nonnull, warn_unused_result))

1617

2070

error_t bring_up_interface(const char *const interface,

1618

2071

const float delay){

1619

int sd = -1;

1620

2072

error_t old_errno = errno;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

2073

int ret;

1623

2074

struct ifreq network;

1624

2075

unsigned int if_index = if_nametoindex(interface);

1625

2076

if(if_index == 0){

1634

2085

}

1635

2086

1636

2087

if(not interface_is_up(interface)){

1637

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

2088

error_t ret_errno = 0, ioctl_errno = 0;

2089

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

1638

2090

ret_errno = errno;

1639

2091

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

1640

2092

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

2093

errno = old_errno;

1641

2094

return ret_errno;

1642

2095

}

1643

network.ifr_flags |= IFF_UP;

2096

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

1644

2097

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2098

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

2099

if(sd == -1){

1647

2100

ret_errno = errno;

1648

2101

perror_plus("socket");

1649

2102

errno = old_errno;

1650

2103

return ret_errno;

1651

2104

}

1652

2105

1653

2106

if(quit_now){

1654

close(sd);

2107

ret = close(sd);

2108

if(ret == -1){

2109

perror_plus("close");

2110

}

1655

2111

errno = old_errno;

1656

2112

return EINTR;

1657

2113

}

1661

2117

interface);

1662

2118

}

1663

2119

1664

/* Raise priviliges */

1665

raise_privileges();

2120

/* Raise privileges */

2121

ret_errno = raise_privileges();

2122

if(ret_errno != 0){

2123

errno = ret_errno;

2124

perror_plus("Failed to raise privileges");

2125

}

1666

2126

1667

2127

#ifdef __linux__

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

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

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

perror_plus("klogctl");

2128

int ret_linux;

2129

bool restore_loglevel = false;

2130

if(ret_errno == 0){

2131

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2132

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

2133

ret_linux = klogctl(8, NULL, 5);

2134

if(ret_linux == -1){

2135

perror_plus("klogctl");

2136

} else {

2137

restore_loglevel = true;

2138

}

1675

2139

}

1676

2140

#endif /* __linux__ */

1677

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

1678

ret_errno = errno;

2141

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

2142

ioctl_errno = errno;

1679

2143

#ifdef __linux__

1680

2144

if(restore_loglevel){

1681

2145

ret_linux = klogctl(7, NULL, 0);

1685

2149

}

1686

2150

#endif /* __linux__ */

1687

2151

1688

/* Lower privileges */

1689

lower_privileges();

2152

/* If raise_privileges() succeeded above */

2153

if(ret_errno == 0){

2154

/* Lower privileges */

2155

ret_errno = lower_privileges();

2156

if(ret_errno != 0){

2157

errno = ret_errno;

2158

perror_plus("Failed to lower privileges");

2159

}

2160

}

1690

2161

1691

2162

/* Close the socket */

1692

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

2163

ret = close(sd);

1693

2164

if(ret == -1){

1694

2165

perror_plus("close");

1695

2166

}

1696

2167

1697

2168

if(ret_setflags == -1){

1698

errno = ret_errno;

2169

errno = ioctl_errno;

1699

2170

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1700

2171

errno = old_errno;

1701

return ret_errno;

2172

return ioctl_errno;

1702

2173

}

1703

2174

} else if(debug){

1704

2175

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

1722

2193

return 0;

1723

2194

}

1724

2195

2196

__attribute__((nonnull, warn_unused_result))

1725

2197

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

1727

2198

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

1730

2199

struct ifreq network;

1731

2200

unsigned int if_index = if_nametoindex(interface);

1732

2201

if(if_index == 0){

1735

2204

return ENXIO;

1736

2205

}

1737

2206

if(interface_is_up(interface)){

2207

error_t ret_errno = 0, ioctl_errno = 0;

1738

2208

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

1739

2209

ret_errno = errno;

1740

2210

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

1741

2211

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

2212

errno = old_errno;

1742

2213

return ret_errno;

1743

2214

}

1744

2215

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

1745

2216

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2217

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

2218

if(sd == -1){

1748

2219

ret_errno = errno;

1749

2220

perror_plus("socket");

1750

2221

errno = old_errno;

1756

2227

interface);

1757

2228

}

1758

2229

1759

/* Raise priviliges */

1760

raise_privileges();

1761

1762

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

1763

ret_errno = errno;

1764

1765

/* Lower privileges */

1766

lower_privileges();

2230

/* Raise privileges */

2231

ret_errno = raise_privileges();

2232

if(ret_errno != 0){

2233

errno = ret_errno;

2234

perror_plus("Failed to raise privileges");

2235

}

2236

2237

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

2238

ioctl_errno = errno;

2239

2240

/* If raise_privileges() succeeded above */

2241

if(ret_errno == 0){

2242

/* Lower privileges */

2243

ret_errno = lower_privileges();

2244

if(ret_errno != 0){

2245

errno = ret_errno;

2246

perror_plus("Failed to lower privileges");

2247

}

2248

}

1767

2249

1768

2250

/* Close the socket */

1769

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

2251

int ret = close(sd);

1770

2252

if(ret == -1){

1771

2253

perror_plus("close");

1772

2254

}

1773

2255

1774

2256

if(ret_setflags == -1){

1775

errno = ret_errno;

2257

errno = ioctl_errno;

1776

2258

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1777

2259

errno = old_errno;

1778

return ret_errno;

2260

return ioctl_errno;

1779

2261

}

1780

2262

} else if(debug){

1781

2263

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

1787

2269

}

1788

2270

1789

2271

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

1790

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

1791

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

1792

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

1793

.interfaces = NULL, .interfaces_size = 0 };

2272

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

2273

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

2274

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

2275

.current_server = NULL, .interfaces = NULL,

2276

.interfaces_size = 0 };

1794

2277

AvahiSServiceBrowser *sb = NULL;

1795

2278

error_t ret_errno;

1796

2279

int ret;

1799

2282

int exitcode = EXIT_SUCCESS;

1800

2283

char *interfaces_to_take_down = NULL;

1801

2284

size_t interfaces_to_take_down_size = 0;

1802

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

1803

bool tempdir_created = false;

2285

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

2286

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

2287

char *tempdir = NULL;

1804

2288

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1805

2289

const char *seckey = PATHDIR "/" SECKEY;

1806

2290

const char *pubkey = PATHDIR "/" PUBKEY;

2291

const char *dh_params_file = NULL;

1807

2292

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

1809

2293

1810

2294

bool gnutls_initialized = false;

1811

2295

bool gpgme_initialized = false;

1863

2347

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

1864

2348

" Diffie-Hellman key exchange",

1865

2349

.group = 2 },

2350

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

2351

.arg = "FILE",

2352

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

2353

" for the Diffie-Hellman key exchange",

2354

.group = 2 },

1866

2355

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

1867

2356

.arg = "STRING",

1868

2357

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

1923

2412

}

1924

2413

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

1925

2414

break;

2415

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

2416

dh_params_file = arg;

2417

break;

1926

2418

case 130: /* --priority */

1927

2419

mc.priority = arg;

1928

2420

break;

1984

2476

goto end;

1985

2477

}

1986

2478

}

1987

2479

1988

2480

{

1989

2481

/* Work around Debian bug #633582:

1990

2482

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

1991

2483

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2484

/* Re-raise privileges */

2485

ret_errno = raise_privileges();

2486

if(ret_errno != 0){

2487

errno = ret_errno;

2488

perror_plus("Failed to raise privileges");

2489

} else {

1994

2490

struct stat st;

1995

2491

1996

2492

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

2010

2506

}

2011

2507

}

2012

2508

}

2013

TEMP_FAILURE_RETRY(close(seckey_fd));

2509

close(seckey_fd);

2014

2510

}

2015

2511

}

2016

2512

2017

2513

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

2018

2514

int pubkey_fd = open(pubkey, O_RDONLY);

2019

2515

if(pubkey_fd == -1){

2031

2527

}

2032

2528

}

2033

2529

}

2034

TEMP_FAILURE_RETRY(close(pubkey_fd));

2035

}

2036

}

2037

2530

close(pubkey_fd);

2531

}

2532

}

2533

2534

if(dh_params_file != NULL

2535

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

2536

int dhparams_fd = open(dh_params_file, O_RDONLY);

2537

if(dhparams_fd == -1){

2538

perror_plus("open");

2539

} else {

2540

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

2541

if(ret == -1){

2542

perror_plus("fstat");

2543

} else {

2544

if(S_ISREG(st.st_mode)

2545

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

2546

ret = fchown(dhparams_fd, uid, gid);

2547

if(ret == -1){

2548

perror_plus("fchown");

2549

}

2550

}

2551

}

2552

close(dhparams_fd);

2553

}

2554

}

2555

2038

2556

/* Lower privileges */

2039

lower_privileges();

2557

ret_errno = lower_privileges();

2558

if(ret_errno != 0){

2559

errno = ret_errno;

2560

perror_plus("Failed to lower privileges");

2561

}

2040

2562

}

2041

2563

}

2042

2564

2066

2588

goto end;

2067

2589

}

2068

2590

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

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

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

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2591

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

2592

}

2593

run_network_hooks("start", interfaces_hooks != NULL ?

2594

interfaces_hooks : "", delay);

2077

2595

}

2078

2596

2079

2597

if(not debug){

2157

2675

2158

2676

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

2159

2677

if(mc.interfaces == NULL){

2160

struct dirent **direntries;

2678

struct dirent **direntries = NULL;

2161

2679

/* Look for any good interfaces */

2162

2680

ret = scandir(sys_class_net, &direntries, good_interface,

2163

2681

alphasort);

2167

2685

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

2168

2686

direntries[i]->d_name);

2169

2687

if(ret_errno != 0){

2688

errno = ret_errno;

2170

2689

perror_plus("argz_add");

2690

free(direntries[i]);

2171

2691

continue;

2172

2692

}

2173

2693

if(debug){

2174

2694

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

2175

2695

direntries[i]->d_name);

2176

2696

}

2697

free(direntries[i]);

2177

2698

}

2178

2699

free(direntries);

2179

2700

} else {

2180

free(direntries);

2701

if(ret == 0){

2702

free(direntries);

2703

}

2181

2704

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

2182

2705

exitcode = EXIT_FAILURE;

2183

2706

goto end;

2206

2729

break;

2207

2730

}

2208

2731

bool interface_was_up = interface_is_up(interface);

2209

ret = bring_up_interface(interface, delay);

2732

errno = bring_up_interface(interface, delay);

2210

2733

if(not interface_was_up){

2211

if(ret != 0){

2212

errno = ret;

2213

perror_plus("Failed to bring up interface");

2734

if(errno != 0){

2735

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

2736

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

2214

2737

} else {

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2738

errno = argz_add(&interfaces_to_take_down,

2739

&interfaces_to_take_down_size,

2740

interface);

2741

if(errno != 0){

2742

perror_plus("argz_add");

2743

}

2218

2744

}

2219

2745

}

2220

2746

}

2236

2762

goto end;

2237

2763

}

2238

2764

2239

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

2765

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

2240

2766

if(ret == -1){

2241

2767

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

2242

2768

exitcode = EX_UNAVAILABLE;

2249

2775

goto end;

2250

2776

}

2251

2777

2252

if(mkdtemp(tempdir) == NULL){

2778

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

2779

tempdir = mkdtemp(run_tempdir);

2780

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

2781

if(debug){

2782

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

2783

run_tempdir, old_tempdir);

2784

}

2785

tempdir = mkdtemp(old_tempdir);

2786

}

2787

if(tempdir == NULL){

2253

2788

perror_plus("mkdtemp");

2254

2789

goto end;

2255

2790

}

2256

tempdir_created = true;

2257

2791

2258

2792

if(quit_now){

2259

2793

goto end;

2331

2865

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

2332

2866

(int)retry_interval);

2333

2867

}

2334

sleep((int)retry_interval);

2868

sleep((unsigned int)retry_interval);

2335

2869

}

2336

2870

2337

if (not quit_now){

2871

if(not quit_now){

2338

2872

exitcode = EXIT_SUCCESS;

2339

2873

}

2340

2874

2395

2929

if(debug){

2396

2930

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

2397

2931

}

2398

2932

2399

2933

ret = avahi_loop_with_timeout(simple_poll,

2400

2934

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

2401

2935

if(debug){

2423

2957

2424

2958

if(gnutls_initialized){

2425

2959

gnutls_certificate_free_credentials(mc.cred);

2426

gnutls_global_deinit();

2427

2960

gnutls_dh_params_deinit(mc.dh_params);

2428

2961

}

2429

2962

2437

2970

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

2438

2971

while(mc.current_server != NULL){

2439

2972

server *next = mc.current_server->next;

2973

#ifdef __GNUC__

2974

#pragma GCC diagnostic push

2975

#pragma GCC diagnostic ignored "-Wcast-qual"

2976

#endif

2977

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

2978

#ifdef __GNUC__

2979

#pragma GCC diagnostic pop

2980

#endif

2440

2981

free(mc.current_server);

2441

2982

mc.current_server = next;

2442

2983

}

2443

2984

}

2444

2985

2445

/* Re-raise priviliges */

2986

/* Re-raise privileges */

2446

2987

{

2447

raise_privileges();

2448

2449

/* Run network hooks */

2450

run_network_hooks("stop", interfaces_hooks != NULL ?

2451

interfaces_hooks : "", delay);

2452

2453

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

2454

{

2455

char *interface = NULL;

2456

while((interface=argz_next(interfaces_to_take_down,

2457

interfaces_to_take_down_size,

2458

interface))){

2459

ret_errno = take_down_interface(interface);

2460

if(ret_errno != 0){

2461

errno = ret_errno;

2462

perror_plus("Failed to take down interface");

2463

}

2464

}

2465

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

2466

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

2467

" down\n");

2468

}

2469

}

2470

2471

lower_privileges_permanently();

2988

ret_errno = raise_privileges();

2989

if(ret_errno != 0){

2990

errno = ret_errno;

2991

perror_plus("Failed to raise privileges");

2992

} else {

2993

2994

/* Run network hooks */

2995

run_network_hooks("stop", interfaces_hooks != NULL ?

2996

interfaces_hooks : "", delay);

2997

2998

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

2999

{

3000

char *interface = NULL;

3001

while((interface=argz_next(interfaces_to_take_down,

3002

interfaces_to_take_down_size,

3003

interface))){

3004

ret_errno = take_down_interface(interface);

3005

if(ret_errno != 0){

3006

errno = ret_errno;

3007

perror_plus("Failed to take down interface");

3008

}

3009

}

3010

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

3011

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

3012

" down\n");

3013

}

3014

}

3015

}

3016

3017

ret_errno = lower_privileges_permanently();

3018

if(ret_errno != 0){

3019

errno = ret_errno;

3020

perror_plus("Failed to lower privileges permanently");

3021

}

2472

3022

}

2473

3023

2474

3024

free(interfaces_to_take_down);

2475

3025

free(interfaces_hooks);

2476

3026

2477

3027

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

2478

if(tempdir_created){

3028

if(tempdir != NULL){

2479

3029

struct dirent **direntries = NULL;

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

2484

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

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

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

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

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

2496

strerror(errno));

2497

}

2498

free(fullname);

3030

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

3031

| O_NOFOLLOW

3032

| O_DIRECTORY

3033

| O_PATH));

3034

if(tempdir_fd == -1){

3035

perror_plus("open");

3036

} else {

3037

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

3038

notdotentries, alphasort);

3039

if(numentries >= 0){

3040

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

3041

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

3042

if(ret == -1){

3043

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

3044

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

3045

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

3046

}

3047

free(direntries[i]);

3048

}

3049

3050

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

3051

free(direntries);

3052

if(numentries == -1){

3053

perror_plus("scandir");

3054

}

3055

ret = rmdir(tempdir);

3056

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

3057

perror_plus("rmdir");

3058

}

2499

3059

}

2500

}

2501

2502

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

2503

free(direntries);

2504

if (numentries == -1){

2505

perror_plus("scandir");

2506

}

2507

ret = rmdir(tempdir);

2508

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

2509

perror_plus("rmdir");

3060

close(tempdir_fd);

2510

3061

}

2511

3062

}

2512

3063