/mandos/release : revision 237.7.342

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(), strcpy() */

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);

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, 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");

540

576

safer_gnutls_strerror(ret));

541

577

goto globalfail;

542

578

}

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

579

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

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

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

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

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

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

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

628

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

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

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

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

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

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

550

751

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

551

752

552

753

return 0;

559

760

return -1;

560

761

}

561

762

763

__attribute__((nonnull, warn_unused_result))

562

764

static int init_gnutls_session(gnutls_session_t *session,

563

765

mandos_context *mc){

564

766

int ret;

611

813

/* ignore client certificate if any. */

612

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

613

815

614

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

616

816

return 0;

617

817

}

618

818

620

820

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

621

821

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

622

822

823

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

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

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

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

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

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

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

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

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

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

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

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

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

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

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

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

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

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

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

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

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

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

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

901

if(devnull == -1){

902

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

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

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

932

_exit(EX_OSERR);

933

}

934

ret = close(devnull);

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

close(helperdir_fd);

958

_exit(EX_UNAVAILABLE);

959

}

960

close(helperdir_fd);

961

#ifdef __GNUC__

962

#pragma GCC diagnostic push

963

#pragma GCC diagnostic ignored "-Wcast-qual"

964

#endif

965

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

966

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

967

interface, debug ? debug_flag : NULL, NULL },

968

environ) == -1){

969

#ifdef __GNUC__

970

#pragma GCC diagnostic pop

971

#endif

972

perror_plus("fexecve");

973

_exit(EXIT_FAILURE);

974

}

975

}

976

if(pid == -1){

977

perror_plus("fork");

978

return false;

979

}

980

int status;

981

pid_t pret = -1;

982

errno = 0;

983

do {

984

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

985

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

986

int errno_raising = 0;

987

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

988

errno_raising = errno;

989

perror_plus("Failed to raise privileges in order to"

990

" kill helper program");

991

}

992

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

993

perror_plus("kill");

994

}

995

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

996

perror_plus("Failed to lower privileges after killing"

997

" helper program");

998

}

999

return false;

1000

}

1001

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

1002

if(pret == -1){

1003

perror_plus("waitpid");

1004

return false;

1005

}

1006

if(WIFEXITED(status)){

1007

if(WEXITSTATUS(status) != 0){

1008

fprintf_plus(stderr, "Error: iprouteadddel exited"

1009

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

1010

return false;

1011

}

1012

return true;

1013

}

1014

if(WIFSIGNALED(status)){

1015

fprintf_plus(stderr, "Error: iprouteadddel died by"

1016

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

1017

return false;

1018

}

1019

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

1020

return false;

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool add_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(true, address, if_index);

1030

}

1031

1032

__attribute__((nonnull, warn_unused_result))

1033

static bool delete_local_route(const char *address,

1034

AvahiIfIndex if_index){

1035

if(debug){

1036

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

1037

}

1038

return add_delete_local_route(false, address, if_index);

1039

}

1040

623

1041

/* Called when a Mandos server is found */

1042

__attribute__((nonnull, warn_unused_result))

624

1043

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

625

1044

AvahiIfIndex if_index,

626

1045

int af, mandos_context *mc){

627

1046

int ret, tcp_sd = -1;

628

1047

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1048

struct sockaddr_storage to;

633

1049

char *buffer = NULL;

634

1050

char *decrypted_buffer = NULL;

635

1051

size_t buffer_length = 0;

638

1054

int retval = -1;

639

1055

gnutls_session_t session;

640

1056

int pf; /* Protocol family */

1057

bool route_added = false;

641

1058

642

1059

errno = 0;

643

1060

701

1118

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

702

1119

}

703

1120

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

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

705

1122

if(tcp_sd < 0){

706

1123

int e = errno;

707

1124

perror_plus("socket");

714

1131

goto mandos_end;

715

1132

}

716

1133

717

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

718

1134

if(af == AF_INET6){

719

to.in6.sin6_family = (sa_family_t)af;

720

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

1135

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

1136

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

1137

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

721

1138

} else { /* IPv4 */

722

to.in.sin_family = (sa_family_t)af;

723

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

1139

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

1140

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

1141

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

724

1142

}

725

1143

if(ret < 0 ){

726

1144

int e = errno;

735

1153

goto mandos_end;

736

1154

}

737

1155

if(af == AF_INET6){

738

to.in6.sin6_port = htons(port);

739

#ifdef __GNUC__

740

#pragma GCC diagnostic push

741

#pragma GCC diagnostic ignored "-Wstrict-aliasing"

742

#endif

743

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

744

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

745

#ifdef __GNUC__

746

#pragma GCC diagnostic pop

747

#endif

1156

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

1157

if(IN6_IS_ADDR_LINKLOCAL

1158

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

748

1159

if(if_index == AVAHI_IF_UNSPEC){

749

1160

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

750

1161

" incomplete without a network interface\n");

752

1163

goto mandos_end;

753

1164

}

754

1165

/* Set the network interface number as scope */

755

to.in6.sin6_scope_id = (uint32_t)if_index;

1166

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

756

1167

}

757

1168

} else {

758

to.in.sin_port = htons(port);

1169

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

759

1170

}

760

1171

761

1172

if(quit_now){

778

1189

}

779

1190

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

780

1191

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

781

const char *pcret;

782

if(af == AF_INET6){

783

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

784

sizeof(addrstr));

785

} else {

786

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

787

sizeof(addrstr));

788

}

789

if(pcret == NULL){

790

perror_plus("inet_ntop");

791

} else {

792

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

793

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

794

}

795

}

796

}

797

798

if(quit_now){

799

errno = EINTR;

800

goto mandos_end;

801

}

802

803

if(af == AF_INET6){

804

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

805

} else {

806

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

807

}

808

if(ret < 0){

809

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

810

int e = errno;

811

perror_plus("connect");

812

errno = e;

813

}

814

goto mandos_end;

815

}

816

817

if(quit_now){

818

errno = EINTR;

819

goto mandos_end;

1192

if(af == AF_INET6){

1193

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

1194

sizeof(struct sockaddr_in6),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

} else {

1198

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

1199

sizeof(struct sockaddr_in),

1200

addrstr, sizeof(addrstr), NULL, 0,

1201

NI_NUMERICHOST);

1202

}

1203

if(ret == EAI_SYSTEM){

1204

perror_plus("getnameinfo");

1205

} else if(ret != 0) {

1206

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

1207

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

1208

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

1209

}

1210

}

1211

1212

if(quit_now){

1213

errno = EINTR;

1214

goto mandos_end;

1215

}

1216

1217

while(true){

1218

if(af == AF_INET6){

1219

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

1220

sizeof(struct sockaddr_in6));

1221

} else {

1222

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

1223

sizeof(struct sockaddr_in));

1224

}

1225

if(ret < 0){

1226

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

1227

and if_index != AVAHI_IF_UNSPEC

1228

and connect_to == NULL

1229

and not route_added and

1230

((af == AF_INET6 and not

1231

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1232

&to)->sin6_addr)))

1233

or (af == AF_INET and

1234

/* Not a a IPv4LL address */

1235

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

1236

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

1237

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

1238

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

1239

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

1240

connect to a Mandos server announced by Avahi on a server

1241

host with a global address. Work around this by retrying

1242

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

1243

1244

Avahi bug reference:

1245

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

1246

https://bugs.debian.org/587961

1247

*/

1248

if(debug){

1249

fprintf_plus(stderr, "Mandos server unreachable, trying"

1250

" direct route\n");

1251

}

1252

int e = errno;

1253

route_added = add_local_route(ip, if_index);

1254

if(route_added){

1255

continue;

1256

}

1257

errno = e;

1258

}

1259

if(errno != ECONNREFUSED or debug){

1260

int e = errno;

1261

perror_plus("connect");

1262

errno = e;

1263

}

1264

goto mandos_end;

1265

}

1266

1267

if(quit_now){

1268

errno = EINTR;

1269

goto mandos_end;

1270

}

1271

break;

820

1272

}

821

1273

822

1274

const char *out = mandos_protocol_version;

1005

1457

1006

1458

mandos_end:

1007

1459

{

1460

if(route_added){

1461

if(not delete_local_route(ip, if_index)){

1462

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

1463

" interface %d", ip, if_index);

1464

}

1465

}

1008

1466

int e = errno;

1009

1467

free(decrypted_buffer);

1010

1468

free(buffer);

1011

1469

if(tcp_sd >= 0){

1012

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

1470

ret = close(tcp_sd);

1013

1471

}

1014

1472

if(ret == -1){

1015

1473

if(e == 0){

1027

1485

return retval;

1028

1486

}

1029

1487

1488

__attribute__((nonnull))

1030

1489

static void resolve_callback(AvahiSServiceResolver *r,

1031

1490

AvahiIfIndex interface,

1032

1491

AvahiProtocol proto,

1040

1499

AVAHI_GCC_UNUSED AvahiStringList *txt,

1041

1500

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1042

1501

flags,

1043

void* mc){

1502

void *mc){

1044

1503

if(r == NULL){

1045

1504

return;

1046

1505

}

1049

1508

timed out */

1050

1509

1051

1510

if(quit_now){

1511

avahi_s_service_resolver_free(r);

1052

1512

return;

1053

1513

}

1054

1514

1099

1559

const char *domain,

1100

1560

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1101

1561

flags,

1102

void* mc){

1562

void *mc){

1103

1563

if(b == NULL){

1104

1564

return;

1105

1565

}

1165

1625

errno = old_errno;

1166

1626

}

1167

1627

1628

__attribute__((nonnull, warn_unused_result))

1168

1629

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

1169

1630

int ret;

1170

1631

error_t ret_errno;

1189

1650

return true;

1190

1651

}

1191

1652

1653

__attribute__((nonnull, warn_unused_result))

1192

1654

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

1193

1655

1194

1656

/* Reject the loopback device */

1236

1698

* corresponds to an acceptable network device.

1237

1699

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

1238

1700

*/

1701

__attribute__((nonnull, warn_unused_result))

1239

1702

int good_interface(const struct dirent *if_entry){

1240

1703

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

1241

1704

return 0;

1259

1722

/*

1260

1723

* This function determines if a network interface is up.

1261

1724

*/

1725

__attribute__((nonnull, warn_unused_result))

1262

1726

bool interface_is_up(const char *interface){

1263

1727

struct ifreq ifr;

1264

1728

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

1275

1739

/*

1276

1740

* This function determines if a network interface is running

1277

1741

*/

1742

__attribute__((nonnull, warn_unused_result))

1278

1743

bool interface_is_running(const char *interface){

1279

1744

struct ifreq ifr;

1280

1745

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

1288

1753

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

1289

1754

}

1290

1755

1756

__attribute__((nonnull, pure, warn_unused_result))

1291

1757

int notdotentries(const struct dirent *direntry){

1292

1758

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

1293

1759

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

1300

1766

}

1301

1767

1302

1768

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

1769

__attribute__((nonnull, warn_unused_result))

1303

1770

int runnable_hook(const struct dirent *direntry){

1304

1771

int ret;

1305

1772

size_t sret;

1313

1780

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

1314

1781

"abcdefghijklmnopqrstuvwxyz"

1315

1782

"0123456789"

1316

"_-");

1783

"_.-");

1317

1784

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

1318

1785

/* Contains non-allowed characters */

1319

1786

if(debug){

1323

1790

return 0;

1324

1791

}

1325

1792

1326

char *fullname = NULL;

1327

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

1328

if(ret < 0){

1329

perror_plus("asprintf");

1330

return 0;

1331

}

1332

1333

ret = stat(fullname, &st);

1793

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

1334

1794

if(ret == -1){

1335

1795

if(debug){

1336

1796

perror_plus("Could not stat hook");

1360

1820

return 1;

1361

1821

}

1362

1822

1823

__attribute__((nonnull, warn_unused_result))

1363

1824

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1364

1825

mandos_context *mc){

1365

1826

int ret;

1369

1830

1370

1831

while(true){

1371

1832

if(mc->current_server == NULL){

1372

if (debug){

1833

if(debug){

1373

1834

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

1374

1835

" No timeout!\n");

1375

1836

}

1376

1837

ret = avahi_simple_poll_iterate(s, -1);

1377

1838

} else {

1378

if (debug){

1839

if(debug){

1379

1840

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

1380

1841

" it, or wait\n");

1381

1842

}

1398

1859

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

1399

1860

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

1400

1861

1401

if (debug){

1862

if(debug){

1402

1863

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

1403

1864

block_time);

1404

1865

}

1426

1887

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

1427

1888

}

1428

1889

if(ret != 0){

1429

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

1890

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

1430

1891

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

1431

1892

}

1432

1893

}

1433

1894

}

1434

1895

}

1435

1896

1436

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

1437

error_t raise_privileges(void){

1438

error_t old_errno = errno;

1439

error_t ret_errno = 0;

1440

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

1441

ret_errno = errno;

1442

perror_plus("seteuid");

1443

}

1444

errno = old_errno;

1445

return ret_errno;

1446

}

1447

1448

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

1449

error_t raise_privileges_permanently(void){

1450

error_t old_errno = errno;

1451

error_t ret_errno = raise_privileges();

1452

if(ret_errno != 0){

1453

errno = old_errno;

1454

return ret_errno;

1455

}

1456

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

1457

ret_errno = errno;

1458

perror_plus("seteuid");

1459

}

1460

errno = old_errno;

1461

return ret_errno;

1462

}

1463

1464

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

1465

error_t lower_privileges(void){

1466

error_t old_errno = errno;

1467

error_t ret_errno = 0;

1468

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

1469

ret_errno = errno;

1470

perror_plus("seteuid");

1471

}

1472

errno = old_errno;

1473

return ret_errno;

1474

}

1475

1476

/* Lower privileges permanently */

1477

error_t lower_privileges_permanently(void){

1478

error_t old_errno = errno;

1479

error_t ret_errno = 0;

1480

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

1481

ret_errno = errno;

1482

perror_plus("setuid");

1483

}

1484

errno = old_errno;

1485

return ret_errno;

1486

}

1487

1488

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

1897

__attribute__((nonnull))

1898

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

1489

1899

const float delay){

1490

struct dirent **direntries;

1900

struct dirent **direntries = NULL;

1901

if(hookdir_fd == -1){

1902

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1903

| O_CLOEXEC);

1904

if(hookdir_fd == -1){

1905

if(errno == ENOENT){

1906

if(debug){

1907

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

1908

" found\n", hookdir);

1909

}

1910

} else {

1911

perror_plus("open");

1912

}

1913

return;

1914

}

1915

}

1916

#ifdef __GLIBC__

1917

#if __GLIBC_PREREQ(2, 15)

1918

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

1919

runnable_hook, alphasort);

1920

#else /* not __GLIBC_PREREQ(2, 15) */

1921

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

1922

alphasort);

1923

#endif /* not __GLIBC_PREREQ(2, 15) */

1924

#else /* not __GLIBC__ */

1925

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

1926

alphasort);

1927

#endif /* not __GLIBC__ */

1928

if(numhooks == -1){

1929

perror_plus("scandir");

1930

return;

1931

}

1491

1932

struct dirent *direntry;

1492

1933

int ret;

1493

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

1494

alphasort);

1495

if(numhooks == -1){

1496

if(errno == ENOENT){

1497

if(debug){

1498

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

1499

" found\n", hookdir);

1500

}

1501

} else {

1502

perror_plus("scandir");

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1939

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

1940

direntry = direntries[i];

1941

if(debug){

1942

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

1943

direntry->d_name);

1503

1944

}

1504

} else {

1505

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

1506

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

1507

direntry = direntries[i];

1508

char *fullname = NULL;

1509

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

1510

if(ret < 0){

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

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

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

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

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

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

1990

if(ret == -1){

1511

1991

perror_plus("asprintf");

1512

continue;

1513

}

1514

if(debug){

1515

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

1516

direntry->d_name);

1517

}

1518

pid_t hook_pid = fork();

1519

if(hook_pid == 0){

1520

/* Child */

1521

/* Raise privileges */

1522

raise_privileges_permanently();

1523

/* Set group */

1524

errno = 0;

1525

ret = setgid(0);

1526

if(ret == -1){

1527

perror_plus("setgid");

1528

}

1529

/* Reset supplementary groups */

1530

errno = 0;

1531

ret = setgroups(0, NULL);

1532

if(ret == -1){

1533

perror_plus("setgroups");

1534

}

1535

dup2(devnull, STDIN_FILENO);

1536

close(devnull);

1537

dup2(STDERR_FILENO, STDOUT_FILENO);

1538

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

1539

if(ret == -1){

1540

perror_plus("setenv");

1541

_exit(EX_OSERR);

1542

}

1543

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

1544

if(ret == -1){

1545

perror_plus("setenv");

1546

_exit(EX_OSERR);

1547

}

1548

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

1549

if(ret == -1){

1550

perror_plus("setenv");

1551

_exit(EX_OSERR);

1552

}

1553

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

1554

if(ret == -1){

1555

perror_plus("setenv");

1556

_exit(EX_OSERR);

1557

}

1558

char *delaystring;

1559

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

1560

if(ret == -1){

1561

perror_plus("asprintf");

1562

_exit(EX_OSERR);

1563

}

1564

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

1565

if(ret == -1){

1566

free(delaystring);

1567

perror_plus("setenv");

1568

_exit(EX_OSERR);

1569

}

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

1570

1996

free(delaystring);

1571

if(connect_to != NULL){

1572

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

1573

if(ret == -1){

1574

perror_plus("setenv");

1575

_exit(EX_OSERR);

1576

}

1577

}

1578

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

1579

perror_plus("execl");

1580

_exit(EXIT_FAILURE);

1581

}

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

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

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

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

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

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

2054

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

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

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

2061

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

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

1582

2065

} else {

1583

int status;

1584

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

1585

perror_plus("waitpid");

1586

free(fullname);

1587

continue;

1588

}

1589

if(WIFEXITED(status)){

1590

if(WEXITSTATUS(status) != 0){

1591

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

1592

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

1593

WEXITSTATUS(status));

1594

free(fullname);

1595

continue;

1596

}

1597

} else if(WIFSIGNALED(status)){

1598

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

1599

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

1600

WTERMSIG(status));

1601

free(fullname);

1602

continue;

1603

} else {

1604

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

1605

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

1606

free(fullname);

1607

continue;

1608

}

1609

}

1610

free(fullname);

1611

if(debug){

1612

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

1613

direntry->d_name);

1614

}

1615

}

1616

close(devnull);

1617

}

1618

return true;

2066

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

2067

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

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

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

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

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

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

1619

2085

}

1620

2086

2087

__attribute__((nonnull, warn_unused_result))

1621

2088

error_t bring_up_interface(const char *const interface,

1622

2089

const float delay){

1623

int sd = -1;

1624

2090

error_t old_errno = errno;

1625

error_t ret_errno = 0;

1626

int ret, ret_setflags;

2091

int ret;

1627

2092

struct ifreq network;

1628

2093

unsigned int if_index = if_nametoindex(interface);

1629

2094

if(if_index == 0){

1638

2103

}

1639

2104

1640

2105

if(not interface_is_up(interface)){

1641

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

2106

error_t ret_errno = 0, ioctl_errno = 0;

2107

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

1642

2108

ret_errno = errno;

1643

2109

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

1644

2110

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

2111

errno = old_errno;

1645

2112

return ret_errno;

1646

2113

}

1647

network.ifr_flags |= IFF_UP;

2114

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

1648

2115

1649

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1650

if(sd < 0){

2116

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

2117

if(sd == -1){

1651

2118

ret_errno = errno;

1652

2119

perror_plus("socket");

1653

2120

errno = old_errno;

1654

2121

return ret_errno;

1655

2122

}

1656

2123

1657

2124

if(quit_now){

1658

close(sd);

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

1659

2129

errno = old_errno;

1660

2130

return EINTR;

1661

2131

}

1665

2135

interface);

1666

2136

}

1667

2137

1668

/* Raise priviliges */

1669

raise_privileges();

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

1670

2144

1671

2145

#ifdef __linux__

1672

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1673

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

1674

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

1675

bool restore_loglevel = true;

1676

if(ret_linux == -1){

1677

restore_loglevel = false;

1678

perror_plus("klogctl");

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

1679

2157

}

1680

2158

#endif /* __linux__ */

1681

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

1682

ret_errno = errno;

2159

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

2160

ioctl_errno = errno;

1683

2161

#ifdef __linux__

1684

2162

if(restore_loglevel){

1685

2163

ret_linux = klogctl(7, NULL, 0);

1689

2167

}

1690

2168

#endif /* __linux__ */

1691

2169

1692

/* Lower privileges */

1693

lower_privileges();

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

1694

2179

1695

2180

/* Close the socket */

1696

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

2181

ret = close(sd);

1697

2182

if(ret == -1){

1698

2183

perror_plus("close");

1699

2184

}

1700

2185

1701

2186

if(ret_setflags == -1){

1702

errno = ret_errno;

2187

errno = ioctl_errno;

1703

2188

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1704

2189

errno = old_errno;

1705

return ret_errno;

2190

return ioctl_errno;

1706

2191

}

1707

2192

} else if(debug){

1708

2193

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

1726

2211

return 0;

1727

2212

}

1728

2213

2214

__attribute__((nonnull, warn_unused_result))

1729

2215

error_t take_down_interface(const char *const interface){

1730

int sd = -1;

1731

2216

error_t old_errno = errno;

1732

error_t ret_errno = 0;

1733

int ret, ret_setflags;

1734

2217

struct ifreq network;

1735

2218

unsigned int if_index = if_nametoindex(interface);

1736

2219

if(if_index == 0){

1739

2222

return ENXIO;

1740

2223

}

1741

2224

if(interface_is_up(interface)){

2225

error_t ret_errno = 0, ioctl_errno = 0;

1742

2226

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

1743

2227

ret_errno = errno;

1744

2228

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

1745

2229

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

2230

errno = old_errno;

1746

2231

return ret_errno;

1747

2232

}

1748

2233

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

1749

2234

1750

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1751

if(sd < 0){

2235

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

2236

if(sd == -1){

1752

2237

ret_errno = errno;

1753

2238

perror_plus("socket");

1754

2239

errno = old_errno;

1760

2245

interface);

1761

2246

}

1762

2247

1763

/* Raise priviliges */

1764

raise_privileges();

1765

1766

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

1767

ret_errno = errno;

1768

1769

/* Lower privileges */

1770

lower_privileges();

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

2254

2255

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

2256

ioctl_errno = errno;

2257

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

1771

2267

1772

2268

/* Close the socket */

1773

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

2269

int ret = close(sd);

1774

2270

if(ret == -1){

1775

2271

perror_plus("close");

1776

2272

}

1777

2273

1778

2274

if(ret_setflags == -1){

1779

errno = ret_errno;

2275

errno = ioctl_errno;

1780

2276

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1781

2277

errno = old_errno;

1782

return ret_errno;

2278

return ioctl_errno;

1783

2279

}

1784

2280

} else if(debug){

1785

2281

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

1791

2287

}

1792

2288

1793

2289

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

1794

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

1795

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

1796

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

1797

.interfaces = NULL, .interfaces_size = 0 };

2290

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

2291

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

2292

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

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

1798

2295

AvahiSServiceBrowser *sb = NULL;

1799

2296

error_t ret_errno;

1800

2297

int ret;

1803

2300

int exitcode = EXIT_SUCCESS;

1804

2301

char *interfaces_to_take_down = NULL;

1805

2302

size_t interfaces_to_take_down_size = 0;

1806

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

1807

bool tempdir_created = false;

2303

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

2304

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

2305

char *tempdir = NULL;

1808

2306

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1809

2307

const char *seckey = PATHDIR "/" SECKEY;

1810

2308

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

1811

2310

char *interfaces_hooks = NULL;

1812

size_t interfaces_hooks_size = 0;

1813

2311

1814

2312

bool gnutls_initialized = false;

1815

2313

bool gpgme_initialized = false;

1867

2365

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

1868

2366

" Diffie-Hellman key exchange",

1869

2367

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

1870

2373

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

1871

2374

.arg = "STRING",

1872

2375

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

1927

2430

}

1928

2431

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

1929

2432

break;

2433

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

2434

dh_params_file = arg;

2435

break;

1930

2436

case 130: /* --priority */

1931

2437

mc.priority = arg;

1932

2438

break;

1988

2494

goto end;

1989

2495

}

1990

2496

}

1991

2497

1992

2498

{

1993

2499

/* Work around Debian bug #633582:

1994

2500

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

1995

2501

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2502

/* Re-raise privileges */

2503

ret_errno = raise_privileges();

2504

if(ret_errno != 0){

2505

errno = ret_errno;

2506

perror_plus("Failed to raise privileges");

2507

} else {

1998

2508

struct stat st;

1999

2509

2000

2510

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

2014

2524

}

2015

2525

}

2016

2526

}

2017

TEMP_FAILURE_RETRY(close(seckey_fd));

2527

close(seckey_fd);

2018

2528

}

2019

2529

}

2020

2530

2021

2531

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

2022

2532

int pubkey_fd = open(pubkey, O_RDONLY);

2023

2533

if(pubkey_fd == -1){

2035

2545

}

2036

2546

}

2037

2547

}

2038

TEMP_FAILURE_RETRY(close(pubkey_fd));

2039

}

2040

}

2041

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

2042

2574

/* Lower privileges */

2043

lower_privileges();

2575

ret_errno = lower_privileges();

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to lower privileges");

2579

}

2044

2580

}

2045

2581

}

2046

2582

2070

2606

goto end;

2071

2607

}

2072

2608

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

2073

interfaces_hooks_size = mc.interfaces_size;

2074

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2075

(int)',');

2076

}

2077

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

2078

interfaces_hooks : "", delay)){

2079

goto end;

2080

}

2609

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

2610

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

2081

2613

}

2082

2614

2083

2615

if(not debug){

2161

2693

2162

2694

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

2163

2695

if(mc.interfaces == NULL){

2164

struct dirent **direntries;

2696

struct dirent **direntries = NULL;

2165

2697

/* Look for any good interfaces */

2166

2698

ret = scandir(sys_class_net, &direntries, good_interface,

2167

2699

alphasort);

2171

2703

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

2172

2704

direntries[i]->d_name);

2173

2705

if(ret_errno != 0){

2706

errno = ret_errno;

2174

2707

perror_plus("argz_add");

2708

free(direntries[i]);

2175

2709

continue;

2176

2710

}

2177

2711

if(debug){

2178

2712

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

2179

2713

direntries[i]->d_name);

2180

2714

}

2715

free(direntries[i]);

2181

2716

}

2182

2717

free(direntries);

2183

2718

} else {

2184

free(direntries);

2719

if(ret == 0){

2720

free(direntries);

2721

}

2185

2722

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

2186

2723

exitcode = EXIT_FAILURE;

2187

2724

goto end;

2210

2747

break;

2211

2748

}

2212

2749

bool interface_was_up = interface_is_up(interface);

2213

ret = bring_up_interface(interface, delay);

2750

errno = bring_up_interface(interface, delay);

2214

2751

if(not interface_was_up){

2215

if(ret != 0){

2216

errno = ret;

2217

perror_plus("Failed to bring up interface");

2752

if(errno != 0){

2753

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

2754

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

2218

2755

} else {

2219

ret_errno = argz_add(&interfaces_to_take_down,

2220

&interfaces_to_take_down_size,

2221

interface);

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

2760

perror_plus("argz_add");

2761

}

2222

2762

}

2223

2763

}

2224

2764

}

2240

2780

goto end;

2241

2781

}

2242

2782

2243

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

2783

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

2244

2784

if(ret == -1){

2245

2785

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

2246

2786

exitcode = EX_UNAVAILABLE;

2253

2793

goto end;

2254

2794

}

2255

2795

2256

if(mkdtemp(tempdir) == NULL){

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

2257

2806

perror_plus("mkdtemp");

2258

2807

goto end;

2259

2808

}

2260

tempdir_created = true;

2261

2809

2262

2810

if(quit_now){

2263

2811

goto end;

2338

2886

sleep((unsigned int)retry_interval);

2339

2887

}

2340

2888

2341

if (not quit_now){

2889

if(not quit_now){

2342

2890

exitcode = EXIT_SUCCESS;

2343

2891

}

2344

2892

2399

2947

if(debug){

2400

2948

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

2401

2949

}

2402

2950

2403

2951

ret = avahi_loop_with_timeout(simple_poll,

2404

2952

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

2405

2953

if(debug){

2441

2989

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

2442

2990

while(mc.current_server != NULL){

2443

2991

server *next = mc.current_server->next;

2992

#ifdef __GNUC__

2993

#pragma GCC diagnostic push

2994

#pragma GCC diagnostic ignored "-Wcast-qual"

2995

#endif

2996

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

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic pop

2999

#endif

2444

3000

free(mc.current_server);

2445

3001

mc.current_server = next;

2446

3002

}

2447

3003

}

2448

3004

2449

/* Re-raise priviliges */

3005

/* Re-raise privileges */

2450

3006

{

2451

raise_privileges();

2452

2453

/* Run network hooks */

2454

run_network_hooks("stop", interfaces_hooks != NULL ?

2455

interfaces_hooks : "", delay);

2456

2457

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

2458

{

2459

char *interface = NULL;

2460

while((interface=argz_next(interfaces_to_take_down,

2461

interfaces_to_take_down_size,

2462

interface))){

2463

ret_errno = take_down_interface(interface);

2464

if(ret_errno != 0){

2465

errno = ret_errno;

2466

perror_plus("Failed to take down interface");

2467

}

2468

}

2469

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

2470

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

2471

" down\n");

2472

}

2473

}

2474

2475

lower_privileges_permanently();

3007

ret_errno = raise_privileges();

3008

if(ret_errno != 0){

3009

errno = ret_errno;

3010

perror_plus("Failed to raise privileges");

3011

} else {

3012

3013

/* Run network hooks */

3014

run_network_hooks("stop", interfaces_hooks != NULL ?

3015

interfaces_hooks : "", delay);

3016

3017

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

3018

{

3019

char *interface = NULL;

3020

while((interface=argz_next(interfaces_to_take_down,

3021

interfaces_to_take_down_size,

3022

interface))){

3023

ret_errno = take_down_interface(interface);

3024

if(ret_errno != 0){

3025

errno = ret_errno;

3026

perror_plus("Failed to take down interface");

3027

}

3028

}

3029

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

3030

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

3031

" down\n");

3032

}

3033

}

3034

}

3035

3036

ret_errno = lower_privileges_permanently();

3037

if(ret_errno != 0){

3038

errno = ret_errno;

3039

perror_plus("Failed to lower privileges permanently");

3040

}

2476

3041

}

2477

3042

2478

3043

free(interfaces_to_take_down);

2479

3044

free(interfaces_hooks);

2480

3045

2481

3046

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

2482

if(tempdir_created){

3047

if(tempdir != NULL){

2483

3048

struct dirent **direntries = NULL;

2484

struct dirent *direntry = NULL;

2485

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

2486

alphasort);

2487

if (numentries > 0){

2488

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

2489

direntry = direntries[i];

2490

char *fullname = NULL;

2491

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

2492

direntry->d_name);

2493

if(ret < 0){

2494

perror_plus("asprintf");

2495

continue;

2496

}

2497

ret = remove(fullname);

2498

if(ret == -1){

2499

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

2500

strerror(errno));

2501

}

2502

free(fullname);

3049

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

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(tempdir_fd == -1){

3054

perror_plus("open");

3055

} else {

3056

#ifdef __GLIBC__

3057

#if __GLIBC_PREREQ(2, 15)

3058

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

3059

notdotentries, alphasort);

3060

#else /* not __GLIBC_PREREQ(2, 15) */

3061

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

3062

alphasort);

3063

#endif /* not __GLIBC_PREREQ(2, 15) */

3064

#else /* not __GLIBC__ */

3065

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

3066

alphasort);

3067

#endif /* not __GLIBC__ */

3068

if(numentries >= 0){

3069

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

3070

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

3071

if(ret == -1){

3072

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

3073

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

3074

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

3075

}

3076

free(direntries[i]);

3077

}

3078

3079

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

3080

free(direntries);

3081

if(numentries == -1){

3082

perror_plus("scandir");

3083

}

3084

ret = rmdir(tempdir);

3085

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

3086

perror_plus("rmdir");

3087

}

2503

3088

}

2504

}

2505

2506

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

2507

free(direntries);

2508

if (numentries == -1){

2509

perror_plus("scandir");

2510

}

2511

ret = rmdir(tempdir);

2512

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

2513

perror_plus("rmdir");

3089

close(tempdir_fd);

2514

3090

}

2515

3091

}

2516

3092