/mandos/trunk : revision 237.4.64

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,

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

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

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,

65

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

66

EAI_SYSTEM, ENETUNREACH,

67

EHOSTUNREACH, ECONNREFUSED, EPROTO,

68

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

69

ENOTEMPTY,

66

70

program_invocation_short_name */

67

71

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

68

72

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

73

77

*/

74

78

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

75

79

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

76

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

80

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

81

unlinkat() */

77

82

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

78

83

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

79

84

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

141

146

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

142

147

char *connect_to = NULL;

143

148

const char *hookdir = HOOKDIR;

149

int hookdir_fd = -1;

144

150

uid_t uid = 65534;

145

151

gid_t gid = 65534;

146

152

183

189

perror(print_text);

184

190

}

185

191

186

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

192

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

187

193

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

188

194

va_list ap;

189

195

va_start (ap, format);

198

204

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

199

205

* "buffer_length" is how much is already used.

200

206

*/

207

__attribute__((nonnull, warn_unused_result))

201

208

size_t incbuffer(char **buffer, size_t buffer_length,

202

209

size_t buffer_capacity){

203

210

if(buffer_length + BUFFER_SIZE > buffer_capacity){

216

223

}

217

224

218

225

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

226

__attribute__((nonnull, warn_unused_result))

219

227

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

220

228

int af, server **current_server){

221

229

int ret;

230

238

.af = af };

231

239

if(new_server->ip == NULL){

232

240

perror_plus("strdup");

241

free(new_server);

233

242

return false;

234

243

}

235

244

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

236

245

if(ret == -1){

237

246

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);

238

256

return false;

239

257

}

240

258

/* Special case of first server */

242

260

new_server->next = new_server;

243

261

new_server->prev = new_server;

244

262

*current_server = new_server;

245

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

246

263

} else {

264

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

247

265

new_server->next = *current_server;

248

266

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

249

267

new_server->prev->next = new_server;

255

273

/*

256

274

* Initialize GPGME.

257

275

*/

258

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

259

const char *tempdir, mandos_context *mc){

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){

260

281

gpgme_error_t rc;

261

282

gpgme_engine_info_t engine_info;

262

283

263

284

/*

264

285

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

265

286

*/

266

bool import_key(const char *filename){

287

bool import_key(const char * const filename){

267

288

int ret;

268

289

int fd;

269

290

gpgme_data_t pgp_data;

288

309

return false;

289

310

}

290

311

291

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

312

ret = close(fd);

292

313

if(ret == -1){

293

314

perror_plus("close");

294

315

}

350

371

* Decrypt OpenPGP data.

351

372

* Returns -1 on error

352

373

*/

374

__attribute__((nonnull, warn_unused_result))

353

375

static ssize_t pgp_packet_decrypt(const char *cryptotext,

354

376

size_t crypto_size,

355

377

char **plaintext,

475

497

return plaintext_length;

476

498

}

477

499

478

static const char * safer_gnutls_strerror(int value){

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){

479

509

const char *ret = gnutls_strerror(value);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

510

return safe_string(ret);

483

511

}

484

512

485

513

/* GnuTLS log function callback */

514

__attribute__((nonnull))

486

515

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

487

516

const char* string){

488

517

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

489

518

}

490

519

520

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

491

521

static int init_gnutls_global(const char *pubkeyfilename,

492

522

const char *seckeyfilename,

523

const char *dhparamsfilename,

493

524

mandos_context *mc){

494

525

int ret;

526

unsigned int uret;

495

527

496

528

if(debug){

497

529

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

498

530

}

499

531

500

ret = gnutls_global_init();

501

if(ret != GNUTLS_E_SUCCESS){

502

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

503

safer_gnutls_strerror(ret));

504

return -1;

505

}

506

507

532

if(debug){

508

533

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

509

534

* - GnuTLS manual

517

542

if(ret != GNUTLS_E_SUCCESS){

518

543

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

519

544

safer_gnutls_strerror(ret));

520

gnutls_global_deinit();

521

545

return -1;

522

546

}

523

547

548

572

safer_gnutls_strerror(ret));

549

573

goto globalfail;

550

574

}

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

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

}

558

747

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

559

748

560

749

return 0;

562

751

globalfail:

563

752

564

753

gnutls_certificate_free_credentials(mc->cred);

565

gnutls_global_deinit();

566

754

gnutls_dh_params_deinit(mc->dh_params);

567

755

return -1;

568

756

}

569

757

758

__attribute__((nonnull, warn_unused_result))

570

759

static int init_gnutls_session(gnutls_session_t *session,

571

760

mandos_context *mc){

572

761

int ret;

619

808

/* ignore client certificate if any. */

620

809

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

621

810

622

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

623

624

811

return 0;

625

812

}

626

813

628

815

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

629

816

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

630

817

818

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

819

__attribute__((warn_unused_result))

820

error_t raise_privileges(void){

821

error_t old_errno = errno;

822

error_t ret_errno = 0;

823

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

824

ret_errno = errno;

825

}

826

errno = old_errno;

827

return ret_errno;

828

}

829

830

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

831

__attribute__((warn_unused_result))

832

error_t raise_privileges_permanently(void){

833

error_t old_errno = errno;

834

error_t ret_errno = raise_privileges();

835

if(ret_errno != 0){

836

errno = old_errno;

837

return ret_errno;

838

}

839

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

840

ret_errno = errno;

841

}

842

errno = old_errno;

843

return ret_errno;

844

}

845

846

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

847

__attribute__((warn_unused_result))

848

error_t lower_privileges(void){

849

error_t old_errno = errno;

850

error_t ret_errno = 0;

851

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

852

ret_errno = errno;

853

}

854

errno = old_errno;

855

return ret_errno;

856

}

857

858

/* Lower privileges permanently */

859

__attribute__((warn_unused_result))

860

error_t lower_privileges_permanently(void){

861

error_t old_errno = errno;

862

error_t ret_errno = 0;

863

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

864

ret_errno = errno;

865

}

866

errno = old_errno;

867

return ret_errno;

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

631

1036

/* Called when a Mandos server is found */

1037

__attribute__((nonnull, warn_unused_result))

632

1038

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

633

1039

AvahiIfIndex if_index,

634

1040

int af, mandos_context *mc){

643

1049

int retval = -1;

644

1050

gnutls_session_t session;

645

1051

int pf; /* Protocol family */

1052

bool route_added = false;

646

1053

647

1054

errno = 0;

648

1055

706

1113

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

707

1114

}

708

1115

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1116

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

710

1117

if(tcp_sd < 0){

711

1118

int e = errno;

712

1119

perror_plus("socket");

719

1126

goto mandos_end;

720

1127

}

721

1128

722

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

723

1129

if(af == AF_INET6){

724

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

725

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

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);

726

1133

} else { /* IPv4 */

727

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

728

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

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);

729

1137

}

730

1138

if(ret < 0 ){

731

1139

int e = errno;

740

1148

goto mandos_end;

741

1149

}

742

1150

if(af == AF_INET6){

743

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

1151

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

744

1152

if(IN6_IS_ADDR_LINKLOCAL

745

1153

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

746

1154

if(if_index == AVAHI_IF_UNSPEC){

801

1209

goto mandos_end;

802

1210

}

803

1211

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;

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;

823

1267

}

824

1268

825

1269

const char *out = mandos_protocol_version;

1008

1452

1009

1453

mandos_end:

1010

1454

{

1455

if(route_added){

1456

if(not delete_local_route(ip, if_index)){

1457

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

1458

" interface %d", ip, if_index);

1459

}

1460

}

1011

1461

int e = errno;

1012

1462

free(decrypted_buffer);

1013

1463

free(buffer);

1014

1464

if(tcp_sd >= 0){

1015

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

1465

ret = close(tcp_sd);

1016

1466

}

1017

1467

if(ret == -1){

1018

1468

if(e == 0){

1030

1480

return retval;

1031

1481

}

1032

1482

1483

__attribute__((nonnull))

1033

1484

static void resolve_callback(AvahiSServiceResolver *r,

1034

1485

AvahiIfIndex interface,

1035

1486

AvahiProtocol proto,

1043

1494

AVAHI_GCC_UNUSED AvahiStringList *txt,

1044

1495

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1045

1496

flags,

1046

void* mc){

1497

void *mc){

1047

1498

if(r == NULL){

1048

1499

return;

1049

1500

}

1052

1503

timed out */

1053

1504

1054

1505

if(quit_now){

1506

avahi_s_service_resolver_free(r);

1055

1507

return;

1056

1508

}

1057

1509

1102

1554

const char *domain,

1103

1555

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1104

1556

flags,

1105

void* mc){

1557

void *mc){

1106

1558

if(b == NULL){

1107

1559

return;

1108

1560

}

1168

1620

errno = old_errno;

1169

1621

}

1170

1622

1623

__attribute__((nonnull, warn_unused_result))

1171

1624

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

1172

1625

int ret;

1173

1626

error_t ret_errno;

1179

1632

errno = ret_errno;

1180

1633

return false;

1181

1634

}

1182

strcpy(ifr->ifr_name, ifname);

1635

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

1636

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

1183

1637

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1184

1638

if(ret == -1){

1185

1639

if(debug){

1192

1646

return true;

1193

1647

}

1194

1648

1649

__attribute__((nonnull, warn_unused_result))

1195

1650

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

1196

1651

1197

1652

/* Reject the loopback device */

1239

1694

* corresponds to an acceptable network device.

1240

1695

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

1241

1696

*/

1697

__attribute__((nonnull, warn_unused_result))

1242

1698

int good_interface(const struct dirent *if_entry){

1243

1699

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

1244

1700

return 0;

1262

1718

/*

1263

1719

* This function determines if a network interface is up.

1264

1720

*/

1721

__attribute__((nonnull, warn_unused_result))

1265

1722

bool interface_is_up(const char *interface){

1266

1723

struct ifreq ifr;

1267

1724

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

1278

1735

/*

1279

1736

* This function determines if a network interface is running

1280

1737

*/

1738

__attribute__((nonnull, warn_unused_result))

1281

1739

bool interface_is_running(const char *interface){

1282

1740

struct ifreq ifr;

1283

1741

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

1291

1749

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

1292

1750

}

1293

1751

1752

__attribute__((nonnull, pure, warn_unused_result))

1294

1753

int notdotentries(const struct dirent *direntry){

1295

1754

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

1296

1755

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

1303

1762

}

1304

1763

1305

1764

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

1765

__attribute__((nonnull, warn_unused_result))

1306

1766

int runnable_hook(const struct dirent *direntry){

1307

1767

int ret;

1308

1768

size_t sret;

1316

1776

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

1317

1777

"abcdefghijklmnopqrstuvwxyz"

1318

1778

"0123456789"

1319

"_-");

1779

"_.-");

1320

1780

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

1321

1781

/* Contains non-allowed characters */

1322

1782

if(debug){

1326

1786

return 0;

1327

1787

}

1328

1788

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);

1789

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

1337

1790

if(ret == -1){

1338

1791

if(debug){

1339

1792

perror_plus("Could not stat hook");

1363

1816

return 1;

1364

1817

}

1365

1818

1819

__attribute__((nonnull, warn_unused_result))

1366

1820

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1367

1821

mandos_context *mc){

1368

1822

int ret;

1436

1890

}

1437

1891

}

1438

1892

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,

1893

__attribute__((nonnull))

1894

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

1492

1895

const float delay){

1493

struct dirent **direntries;

1494

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

1495

alphasort);

1896

struct dirent **direntries = NULL;

1897

if(hookdir_fd == -1){

1898

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1899

| O_CLOEXEC);

1900

if(hookdir_fd == -1){

1901

if(errno == ENOENT){

1902

if(debug){

1903

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

1904

" found\n", hookdir);

1905

}

1906

} else {

1907

perror_plus("open");

1908

}

1909

return;

1910

}

1911

}

1912

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

1913

runnable_hook, alphasort);

1496

1914

if(numhooks == -1){

1497

if(errno == ENOENT){

1498

if(debug){

1499

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

1500

" found\n", hookdir);

1501

}

1502

} else {

1503

perror_plus("scandir");

1915

perror_plus("scandir");

1916

return;

1917

}

1918

struct dirent *direntry;

1919

int ret;

1920

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

1921

if(devnull == -1){

1922

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

1923

return;

1924

}

1925

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

1926

direntry = direntries[i];

1927

if(debug){

1928

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

1929

direntry->d_name);

1504

1930

}

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){

1931

pid_t hook_pid = fork();

1932

if(hook_pid == 0){

1933

/* Child */

1934

/* Raise privileges */

1935

errno = raise_privileges_permanently();

1936

if(errno != 0){

1937

perror_plus("Failed to raise privileges");

1938

_exit(EX_NOPERM);

1939

}

1940

/* Set group */

1941

errno = 0;

1942

ret = setgid(0);

1943

if(ret == -1){

1944

perror_plus("setgid");

1945

_exit(EX_NOPERM);

1946

}

1947

/* Reset supplementary groups */

1948

errno = 0;

1949

ret = setgroups(0, NULL);

1950

if(ret == -1){

1951

perror_plus("setgroups");

1952

_exit(EX_NOPERM);

1953

}

1954

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

1955

if(ret == -1){

1956

perror_plus("setenv");

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("setenv");

1962

_exit(EX_OSERR);

1963

}

1964

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

1965

if(ret == -1){

1966

perror_plus("setenv");

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

if(ret == -1){

1971

perror_plus("setenv");

1972

_exit(EX_OSERR);

1973

}

1974

char *delaystring;

1975

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

1976

if(ret == -1){

1514

1977

perror_plus("asprintf");

1515

continue;

1516

}

1517

if(debug){

1518

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

1519

direntry->d_name);

1520

}

1521

pid_t hook_pid = fork();

1522

if(hook_pid == 0){

1523

/* Child */

1524

/* Raise privileges */

1525

raise_privileges_permanently();

1526

/* Set group */

1527

errno = 0;

1528

ret = setgid(0);

1529

if(ret == -1){

1530

perror_plus("setgid");

1531

}

1532

/* Reset supplementary groups */

1533

errno = 0;

1534

ret = setgroups(0, NULL);

1535

if(ret == -1){

1536

perror_plus("setgroups");

1537

}

1538

dup2(devnull, STDIN_FILENO);

1539

close(devnull);

1540

dup2(STDERR_FILENO, STDOUT_FILENO);

1541

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

1542

if(ret == -1){

1543

perror_plus("setenv");

1544

_exit(EX_OSERR);

1545

}

1546

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

1547

if(ret == -1){

1548

perror_plus("setenv");

1549

_exit(EX_OSERR);

1550

}

1551

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

1552

if(ret == -1){

1553

perror_plus("setenv");

1554

_exit(EX_OSERR);

1555

}

1556

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

1557

if(ret == -1){

1558

perror_plus("setenv");

1559

_exit(EX_OSERR);

1560

}

1561

char *delaystring;

1562

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

1563

if(ret == -1){

1564

perror_plus("asprintf");

1565

_exit(EX_OSERR);

1566

}

1567

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

1568

if(ret == -1){

1569

free(delaystring);

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1978

_exit(EX_OSERR);

1979

}

1980

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

1981

if(ret == -1){

1573

1982

free(delaystring);

1574

if(connect_to != NULL){

1575

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

1576

if(ret == -1){

1577

perror_plus("setenv");

1578

_exit(EX_OSERR);

1579

}

1580

}

1581

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

1582

perror_plus("execl");

1583

_exit(EXIT_FAILURE);

1584

}

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

free(delaystring);

1987

if(connect_to != NULL){

1988

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

1989

if(ret == -1){

1990

perror_plus("setenv");

1991

_exit(EX_OSERR);

1992

}

1993

}

1994

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

1995

direntry->d_name,

1996

O_RDONLY));

1997

if(hook_fd == -1){

1998

perror_plus("openat");

1999

_exit(EXIT_FAILURE);

2000

}

2001

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

2002

perror_plus("close");

2003

_exit(EXIT_FAILURE);

2004

}

2005

ret = dup2(devnull, STDIN_FILENO);

2006

if(ret == -1){

2007

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

2008

_exit(EX_OSERR);

2009

}

2010

ret = close(devnull);

2011

if(ret == -1){

2012

perror_plus("close");

2013

_exit(EX_OSERR);

2014

}

2015

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2016

if(ret == -1){

2017

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

2018

_exit(EX_OSERR);

2019

}

2020

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

2021

environ) == -1){

2022

perror_plus("fexecve");

2023

_exit(EXIT_FAILURE);

2024

}

2025

} else {

2026

if(hook_pid == -1){

2027

perror_plus("fork");

2028

free(direntry);

2029

continue;

2030

}

2031

int status;

2032

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

2033

perror_plus("waitpid");

2034

free(direntry);

2035

continue;

2036

}

2037

if(WIFEXITED(status)){

2038

if(WEXITSTATUS(status) != 0){

2039

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

2040

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

2041

WEXITSTATUS(status));

2042

free(direntry);

2043

continue;

2044

}

2045

} else if(WIFSIGNALED(status)){

2046

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

2047

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

2048

WTERMSIG(status));

2049

free(direntry);

2050

continue;

1585

2051

} else {

1586

int status;

1587

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

1588

perror_plus("waitpid");

1589

free(fullname);

1590

continue;

1591

}

1592

if(WIFEXITED(status)){

1593

if(WEXITSTATUS(status) != 0){

1594

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

1595

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

1596

WEXITSTATUS(status));

1597

free(fullname);

1598

continue;

1599

}

1600

} else if(WIFSIGNALED(status)){

1601

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

1602

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

1603

WTERMSIG(status));

1604

free(fullname);

1605

continue;

1606

} else {

1607

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

1608

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

1609

free(fullname);

1610

continue;

1611

}

1612

}

1613

free(fullname);

1614

if(debug){

1615

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

1616

direntry->d_name);

1617

}

1618

}

1619

close(devnull);

1620

}

1621

return true;

2052

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

2053

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

2054

free(direntry);

2055

continue;

2056

}

2057

}

2058

if(debug){

2059

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

2060

direntry->d_name);

2061

}

2062

free(direntry);

2063

}

2064

free(direntries);

2065

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

2066

perror_plus("close");

2067

} else {

2068

hookdir_fd = -1;

2069

}

2070

close(devnull);

1622

2071

}

1623

2072

2073

__attribute__((nonnull, warn_unused_result))

1624

2074

error_t bring_up_interface(const char *const interface,

1625

2075

const float delay){

1626

int sd = -1;

1627

2076

error_t old_errno = errno;

1628

error_t ret_errno = 0;

1629

int ret, ret_setflags;

2077

int ret;

1630

2078

struct ifreq network;

1631

2079

unsigned int if_index = if_nametoindex(interface);

1632

2080

if(if_index == 0){

1641

2089

}

1642

2090

1643

2091

if(not interface_is_up(interface)){

1644

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

2092

error_t ret_errno = 0, ioctl_errno = 0;

2093

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

1645

2094

ret_errno = errno;

1646

2095

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

1647

2096

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

2097

errno = old_errno;

1648

2098

return ret_errno;

1649

2099

}

1650

network.ifr_flags |= IFF_UP;

2100

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

1651

2101

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

2102

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

2103

if(sd == -1){

1654

2104

ret_errno = errno;

1655

2105

perror_plus("socket");

1656

2106

errno = old_errno;

1657

2107

return ret_errno;

1658

2108

}

1659

2109

1660

2110

if(quit_now){

1661

close(sd);

2111

ret = close(sd);

2112

if(ret == -1){

2113

perror_plus("close");

2114

}

1662

2115

errno = old_errno;

1663

2116

return EINTR;

1664

2117

}

1668

2121

interface);

1669

2122

}

1670

2123

1671

/* Raise priviliges */

1672

raise_privileges();

2124

/* Raise privileges */

2125

ret_errno = raise_privileges();

2126

if(ret_errno != 0){

2127

errno = ret_errno;

2128

perror_plus("Failed to raise privileges");

2129

}

1673

2130

1674

2131

#ifdef __linux__

1675

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1676

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

1677

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

1678

bool restore_loglevel = true;

1679

if(ret_linux == -1){

1680

restore_loglevel = false;

1681

perror_plus("klogctl");

2132

int ret_linux;

2133

bool restore_loglevel = false;

2134

if(ret_errno == 0){

2135

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2136

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

2137

ret_linux = klogctl(8, NULL, 5);

2138

if(ret_linux == -1){

2139

perror_plus("klogctl");

2140

} else {

2141

restore_loglevel = true;

2142

}

1682

2143

}

1683

2144

#endif /* __linux__ */

1684

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

1685

ret_errno = errno;

2145

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

2146

ioctl_errno = errno;

1686

2147

#ifdef __linux__

1687

2148

if(restore_loglevel){

1688

2149

ret_linux = klogctl(7, NULL, 0);

1692

2153

}

1693

2154

#endif /* __linux__ */

1694

2155

1695

/* Lower privileges */

1696

lower_privileges();

2156

/* If raise_privileges() succeeded above */

2157

if(ret_errno == 0){

2158

/* Lower privileges */

2159

ret_errno = lower_privileges();

2160

if(ret_errno != 0){

2161

errno = ret_errno;

2162

perror_plus("Failed to lower privileges");

2163

}

2164

}

1697

2165

1698

2166

/* Close the socket */

1699

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

2167

ret = close(sd);

1700

2168

if(ret == -1){

1701

2169

perror_plus("close");

1702

2170

}

1703

2171

1704

2172

if(ret_setflags == -1){

1705

errno = ret_errno;

2173

errno = ioctl_errno;

1706

2174

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1707

2175

errno = old_errno;

1708

return ret_errno;

2176

return ioctl_errno;

1709

2177

}

1710

2178

} else if(debug){

1711

2179

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

1729

2197

return 0;

1730

2198

}

1731

2199

2200

__attribute__((nonnull, warn_unused_result))

1732

2201

error_t take_down_interface(const char *const interface){

1733

2202

error_t old_errno = errno;

1734

2203

struct ifreq network;

1739

2208

return ENXIO;

1740

2209

}

1741

2210

if(interface_is_up(interface)){

1742

error_t ret_errno = 0;

2211

error_t ret_errno = 0, ioctl_errno = 0;

1743

2212

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

1744

2213

ret_errno = errno;

1745

2214

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

1746

2215

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

2216

errno = old_errno;

1747

2217

return ret_errno;

1748

2218

}

1749

2219

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

1750

2220

1751

2221

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

1752

if(sd < 0){

2222

if(sd == -1){

1753

2223

ret_errno = errno;

1754

2224

perror_plus("socket");

1755

2225

errno = old_errno;

1761

2231

interface);

1762

2232

}

1763

2233

1764

/* Raise priviliges */

1765

raise_privileges();

2234

/* Raise privileges */

2235

ret_errno = raise_privileges();

2236

if(ret_errno != 0){

2237

errno = ret_errno;

2238

perror_plus("Failed to raise privileges");

2239

}

1766

2240

1767

2241

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

1768

ret_errno = errno;

2242

ioctl_errno = errno;

1769

2243

1770

/* Lower privileges */

1771

lower_privileges();

2244

/* If raise_privileges() succeeded above */

2245

if(ret_errno == 0){

2246

/* Lower privileges */

2247

ret_errno = lower_privileges();

2248

if(ret_errno != 0){

2249

errno = ret_errno;

2250

perror_plus("Failed to lower privileges");

2251

}

2252

}

1772

2253

1773

2254

/* Close the socket */

1774

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

2255

int ret = close(sd);

1775

2256

if(ret == -1){

1776

2257

perror_plus("close");

1777

2258

}

1778

2259

1779

2260

if(ret_setflags == -1){

1780

errno = ret_errno;

2261

errno = ioctl_errno;

1781

2262

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1782

2263

errno = old_errno;

1783

return ret_errno;

2264

return ioctl_errno;

1784

2265

}

1785

2266

} else if(debug){

1786

2267

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

1792

2273

}

1793

2274

1794

2275

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

1795

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

1796

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

1797

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

1798

.interfaces = NULL, .interfaces_size = 0 };

2276

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

2277

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

2278

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

2279

.current_server = NULL, .interfaces = NULL,

2280

.interfaces_size = 0 };

1799

2281

AvahiSServiceBrowser *sb = NULL;

1800

2282

error_t ret_errno;

1801

2283

int ret;

1804

2286

int exitcode = EXIT_SUCCESS;

1805

2287

char *interfaces_to_take_down = NULL;

1806

2288

size_t interfaces_to_take_down_size = 0;

1807

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

1808

bool tempdir_created = false;

2289

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

2290

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

2291

char *tempdir = NULL;

1809

2292

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1810

2293

const char *seckey = PATHDIR "/" SECKEY;

1811

2294

const char *pubkey = PATHDIR "/" PUBKEY;

2295

const char *dh_params_file = NULL;

1812

2296

char *interfaces_hooks = NULL;

1813

2297

1814

2298

bool gnutls_initialized = false;

1867

2351

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

1868

2352

" Diffie-Hellman key exchange",

1869

2353

.group = 2 },

2354

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

2355

.arg = "FILE",

2356

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

2357

" for the Diffie-Hellman key exchange",

2358

.group = 2 },

1870

2359

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

1871

2360

.arg = "STRING",

1872

2361

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

1927

2416

}

1928

2417

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

1929

2418

break;

2419

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

2420

dh_params_file = arg;

2421

break;

1930

2422

case 130: /* --priority */

1931

2423

mc.priority = arg;

1932

2424

break;

1988

2480

goto end;

1989

2481

}

1990

2482

}

1991

2483

1992

2484

{

1993

2485

/* Work around Debian bug #633582:

1994

2486

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

1995

2487

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2488

/* Re-raise privileges */

2489

ret_errno = raise_privileges();

2490

if(ret_errno != 0){

2491

errno = ret_errno;

2492

perror_plus("Failed to raise privileges");

2493

} else {

1998

2494

struct stat st;

1999

2495

2000

2496

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

2014

2510

}

2015

2511

}

2016

2512

}

2017

TEMP_FAILURE_RETRY(close(seckey_fd));

2513

close(seckey_fd);

2018

2514

}

2019

2515

}

2020

2516

2021

2517

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

2022

2518

int pubkey_fd = open(pubkey, O_RDONLY);

2023

2519

if(pubkey_fd == -1){

2035

2531

}

2036

2532

}

2037

2533

}

2038

TEMP_FAILURE_RETRY(close(pubkey_fd));

2039

}

2040

}

2041

2534

close(pubkey_fd);

2535

}

2536

}

2537

2538

if(dh_params_file != NULL

2539

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

2540

int dhparams_fd = open(dh_params_file, O_RDONLY);

2541

if(dhparams_fd == -1){

2542

perror_plus("open");

2543

} else {

2544

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

2545

if(ret == -1){

2546

perror_plus("fstat");

2547

} else {

2548

if(S_ISREG(st.st_mode)

2549

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

2550

ret = fchown(dhparams_fd, uid, gid);

2551

if(ret == -1){

2552

perror_plus("fchown");

2553

}

2554

}

2555

}

2556

close(dhparams_fd);

2557

}

2558

}

2559

2042

2560

/* Lower privileges */

2043

lower_privileges();

2561

ret_errno = lower_privileges();

2562

if(ret_errno != 0){

2563

errno = ret_errno;

2564

perror_plus("Failed to lower privileges");

2565

}

2044

2566

}

2045

2567

}

2046

2568

2072

2594

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

2073

2595

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

2074

2596

}

2075

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

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2597

run_network_hooks("start", interfaces_hooks != NULL ?

2598

interfaces_hooks : "", delay);

2079

2599

}

2080

2600

2081

2601

if(not debug){

2159

2679

2160

2680

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

2161

2681

if(mc.interfaces == NULL){

2162

struct dirent **direntries;

2682

struct dirent **direntries = NULL;

2163

2683

/* Look for any good interfaces */

2164

2684

ret = scandir(sys_class_net, &direntries, good_interface,

2165

2685

alphasort);

2171

2691

if(ret_errno != 0){

2172

2692

errno = ret_errno;

2173

2693

perror_plus("argz_add");

2694

free(direntries[i]);

2174

2695

continue;

2175

2696

}

2176

2697

if(debug){

2177

2698

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

2178

2699

direntries[i]->d_name);

2179

2700

}

2701

free(direntries[i]);

2180

2702

}

2181

2703

free(direntries);

2182

2704

} else {

2183

free(direntries);

2705

if(ret == 0){

2706

free(direntries);

2707

}

2184

2708

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

2185

2709

exitcode = EXIT_FAILURE;

2186

2710

goto end;

2209

2733

break;

2210

2734

}

2211

2735

bool interface_was_up = interface_is_up(interface);

2212

ret = bring_up_interface(interface, delay);

2736

errno = bring_up_interface(interface, delay);

2213

2737

if(not interface_was_up){

2214

if(ret != 0){

2215

errno = ret;

2216

perror_plus("Failed to bring up interface");

2738

if(errno != 0){

2739

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

2740

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

2217

2741

} else {

2218

ret_errno = argz_add(&interfaces_to_take_down,

2219

&interfaces_to_take_down_size,

2220

interface);

2221

if(ret_errno != 0){

2222

errno = ret_errno;

2742

errno = argz_add(&interfaces_to_take_down,

2743

&interfaces_to_take_down_size,

2744

interface);

2745

if(errno != 0){

2223

2746

perror_plus("argz_add");

2224

2747

}

2225

2748

}

2243

2766

goto end;

2244

2767

}

2245

2768

2246

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

2769

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

2247

2770

if(ret == -1){

2248

2771

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

2249

2772

exitcode = EX_UNAVAILABLE;

2256

2779

goto end;

2257

2780

}

2258

2781

2259

if(mkdtemp(tempdir) == NULL){

2782

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

2783

tempdir = mkdtemp(run_tempdir);

2784

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

2785

if(debug){

2786

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

2787

run_tempdir, old_tempdir);

2788

}

2789

tempdir = mkdtemp(old_tempdir);

2790

}

2791

if(tempdir == NULL){

2260

2792

perror_plus("mkdtemp");

2261

2793

goto end;

2262

2794

}

2263

tempdir_created = true;

2264

2795

2265

2796

if(quit_now){

2266

2797

goto end;

2402

2933

if(debug){

2403

2934

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

2404

2935

}

2405

2936

2406

2937

ret = avahi_loop_with_timeout(simple_poll,

2407

2938

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

2408

2939

if(debug){

2430

2961

2431

2962

if(gnutls_initialized){

2432

2963

gnutls_certificate_free_credentials(mc.cred);

2433

gnutls_global_deinit();

2434

2964

gnutls_dh_params_deinit(mc.dh_params);

2435

2965

}

2436

2966

2444

2974

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

2445

2975

while(mc.current_server != NULL){

2446

2976

server *next = mc.current_server->next;

2977

#ifdef __GNUC__

2978

#pragma GCC diagnostic push

2979

#pragma GCC diagnostic ignored "-Wcast-qual"

2980

#endif

2981

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

2982

#ifdef __GNUC__

2983

#pragma GCC diagnostic pop

2984

#endif

2447

2985

free(mc.current_server);

2448

2986

mc.current_server = next;

2449

2987

}

2450

2988

}

2451

2989

2452

/* Re-raise priviliges */

2990

/* Re-raise privileges */

2453

2991

{

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();

2992

ret_errno = raise_privileges();

2993

if(ret_errno != 0){

2994

errno = ret_errno;

2995

perror_plus("Failed to raise privileges");

2996

} else {

2997

2998

/* Run network hooks */

2999

run_network_hooks("stop", interfaces_hooks != NULL ?

3000

interfaces_hooks : "", delay);

3001

3002

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

3003

{

3004

char *interface = NULL;

3005

while((interface=argz_next(interfaces_to_take_down,

3006

interfaces_to_take_down_size,

3007

interface))){

3008

ret_errno = take_down_interface(interface);

3009

if(ret_errno != 0){

3010

errno = ret_errno;

3011

perror_plus("Failed to take down interface");

3012

}

3013

}

3014

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

3015

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

3016

" down\n");

3017

}

3018

}

3019

}

3020

3021

ret_errno = lower_privileges_permanently();

3022

if(ret_errno != 0){

3023

errno = ret_errno;

3024

perror_plus("Failed to lower privileges permanently");

3025

}

2479

3026

}

2480

3027

2481

3028

free(interfaces_to_take_down);

2482

3029

free(interfaces_hooks);

2483

3030

3031

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

3032

uintmax_t level){

3033

struct dirent **direntries = NULL;

3034

int dret;

3035

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

3036

O_RDONLY

3037

| O_NOFOLLOW

3038

| O_DIRECTORY

3039

| O_PATH));

3040

if(dir_fd == -1){

3041

perror_plus("open");

3042

}

3043

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

3044

notdotentries, alphasort);

3045

if(numentries >= 0){

3046

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

3047

if(debug){

3048

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

3049

dirname, direntries[i]->d_name);

3050

}

3051

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

3052

if(dret == -1){

3053

if(errno == EISDIR){

3054

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

3055

AT_REMOVEDIR);

3056

}

3057

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

3058

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

3059

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

3060

/* Recurse only in this special case */

3061

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

3062

dret = 0;

3063

}

3064

if(dret == -1){

3065

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

3066

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

3067

}

3068

}

3069

free(direntries[i]);

3070

}

3071

3072

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

3073

free(direntries);

3074

if(numentries == -1){

3075

perror_plus("scandirat");

3076

}

3077

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3078

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

3079

perror_plus("rmdir");

3080

}

3081

} else {

3082

perror_plus("scandirat");

3083

}

3084

close(dir_fd);

3085

}

3086

2484

3087

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

2485

if(tempdir_created){

2486

struct dirent **direntries = NULL;

2487

struct dirent *direntry = NULL;

2488

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

2489

alphasort);

2490

if(numentries > 0){

2491

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

2492

direntry = direntries[i];

2493

char *fullname = NULL;

2494

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

2495

direntry->d_name);

2496

if(ret < 0){

2497

perror_plus("asprintf");

2498

continue;

2499

}

2500

ret = remove(fullname);

2501

if(ret == -1){

2502

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

2503

strerror(errno));

2504

}

2505

free(fullname);

2506

}

2507

}

2508

2509

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

2510

free(direntries);

2511

if(numentries == -1){

2512

perror_plus("scandir");

2513

}

2514

ret = rmdir(tempdir);

2515

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

2516

perror_plus("rmdir");

2517

}

3088

if(tempdir != NULL){

3089

clean_dir_at(-1, tempdir, 0);

2518

3090

}

2519

3091

2520

3092

if(quit_now){