/mandos/trunk : revision 640

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

41

42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

strtof(), abort() */

48

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

49

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

50

asprintf(), strncpy() */

49

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

50

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

51

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

52

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

53

sockaddr_in6, PF_INET6,

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

getnameinfo() */

60

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

58

inet_pton(), connect() */

59

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

61

60

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

62

61

*/

63

62

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

73

72

*/

74

73

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

75

74

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

76

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

77

unlinkat() */

78

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

75

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

76

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

79

77

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

80

78

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

81

79

argp_state, struct argp,

93

91

argz_delete(), argz_append(),

94

92

argz_stringify(), argz_add(),

95

93

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

98

94

99

95

#ifdef __linux__

100

96

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

142

138

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

143

139

char *connect_to = NULL;

144

140

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

141

uid_t uid = 65534;

147

142

gid_t gid = 65534;

148

143

185

180

perror(print_text);

186

181

}

187

182

188

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

183

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

189

184

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

190

185

va_list ap;

191

186

va_start (ap, format);

200

195

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

201

196

* "buffer_length" is how much is already used.

202

197

*/

203

__attribute__((nonnull, warn_unused_result))

204

198

size_t incbuffer(char **buffer, size_t buffer_length,

205

199

size_t buffer_capacity){

206

200

if(buffer_length + BUFFER_SIZE > buffer_capacity){

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;

201

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

202

if(buffer == NULL){

213

203

return 0;

214

204

}

215

*buffer = new_buf;

216

205

buffer_capacity += BUFFER_SIZE;

217

206

}

218

207

return buffer_capacity;

219

208

}

220

209

221

210

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

222

__attribute__((nonnull, warn_unused_result))

223

211

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

224

212

int af, server **current_server){

225

213

int ret;

234

222

.af = af };

235

223

if(new_server->ip == NULL){

236

224

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);

252

225

return false;

253

226

}

254

227

/* Special case of first server */

256

229

new_server->next = new_server;

257

230

new_server->prev = new_server;

258

231

*current_server = new_server;

232

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

259

233

} else {

260

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

261

234

new_server->next = *current_server;

262

235

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

263

236

new_server->prev->next = new_server;

264

237

(*current_server)->prev = new_server;

265

238

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

266

244

return true;

267

245

}

268

246

269

247

/*

270

248

* Initialize GPGME.

271

249

*/

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){

250

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

251

const char *tempdir, mandos_context *mc){

277

252

gpgme_error_t rc;

278

253

gpgme_engine_info_t engine_info;

279

254

280

255

/*

281

256

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

282

257

*/

283

bool import_key(const char * const filename){

258

bool import_key(const char *filename){

284

259

int ret;

285

260

int fd;

286

261

gpgme_data_t pgp_data;

305

280

return false;

306

281

}

307

282

308

ret = close(fd);

283

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

309

284

if(ret == -1){

310

285

perror_plus("close");

311

286

}

367

342

* Decrypt OpenPGP data.

368

343

* Returns -1 on error

369

344

*/

370

__attribute__((nonnull, warn_unused_result))

371

345

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

346

size_t crypto_size,

373

347

char **plaintext,

493

467

return plaintext_length;

494

468

}

495

469

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){

470

static const char * safer_gnutls_strerror(int value){

505

471

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

507

475

}

508

476

509

477

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

478

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

512

479

const char* string){

513

480

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

514

481

}

515

482

516

__attribute__((nonnull, warn_unused_result))

517

483

static int init_gnutls_global(const char *pubkeyfilename,

518

484

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

485

mandos_context *mc){

521

486

int ret;

522

unsigned int uret;

523

487

524

488

if(debug){

525

489

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

576

540

safer_gnutls_strerror(ret));

577

541

goto globalfail;

578

542

}

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

}

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

751

550

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

752

551

753

552

return 0;

760

559

return -1;

761

560

}

762

561

763

__attribute__((nonnull, warn_unused_result))

764

562

static int init_gnutls_session(gnutls_session_t *session,

765

563

mandos_context *mc){

766

564

int ret;

813

611

/* ignore client certificate if any. */

814

612

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

613

614

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

816

616

return 0;

817

617

}

818

618

820

620

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

821

621

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

822

622

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

1041

623

/* Called when a Mandos server is found */

1042

__attribute__((nonnull, warn_unused_result))

1043

624

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

1044

625

AvahiIfIndex if_index,

1045

626

int af, mandos_context *mc){

1046

627

int ret, tcp_sd = -1;

1047

628

ssize_t sret;

1048

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1049

633

char *buffer = NULL;

1050

634

char *decrypted_buffer = NULL;

1051

635

size_t buffer_length = 0;

1054

638

int retval = -1;

1055

639

gnutls_session_t session;

1056

640

int pf; /* Protocol family */

1057

bool route_added = false;

1058

641

1059

642

errno = 0;

1060

643

1118

701

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

1119

702

}

1120

703

1121

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

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1122

705

if(tcp_sd < 0){

1123

706

int e = errno;

1124

707

perror_plus("socket");

1131

714

goto mandos_end;

1132

715

}

1133

716

717

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

1134

718

if(af == AF_INET6){

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);

719

to.in6.sin6_family = (sa_family_t)af;

720

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

1138

721

} else { /* IPv4 */

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);

722

to.in.sin_family = (sa_family_t)af;

723

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

1142

724

}

1143

725

if(ret < 0 ){

1144

726

int e = errno;

1153

735

goto mandos_end;

1154

736

}

1155

737

if(af == AF_INET6){

1156

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

1157

if(IN6_IS_ADDR_LINKLOCAL

1158

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

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

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

741

-Wunreachable-code*/

1159

742

if(if_index == AVAHI_IF_UNSPEC){

1160

743

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

1161

744

" incomplete without a network interface\n");

1163

746

goto mandos_end;

1164

747

}

1165

748

/* Set the network interface number as scope */

1166

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

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1167

750

}

1168

751

} else {

1169

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

752

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

753

-Wconversion and

754

-Wunreachable-code */

1170

755

}

1171

756

1172

757

if(quit_now){

1189

774

}

1190

775

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1191

776

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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;

777

const char *pcret;

778

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

781

} else {

782

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

783

sizeof(addrstr));

784

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

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

789

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

790

}

791

}

792

}

793

794

if(quit_now){

795

errno = EINTR;

796

goto mandos_end;

797

}

798

799

if(af == AF_INET6){

800

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

801

} else {

802

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

803

}

804

if(ret < 0){

805

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

806

int e = errno;

807

perror_plus("connect");

808

errno = e;

809

}

810

goto mandos_end;

811

}

812

813

if(quit_now){

814

errno = EINTR;

815

goto mandos_end;

1272

816

}

1273

817

1274

818

const char *out = mandos_protocol_version;

1457

1001

1458

1002

mandos_end:

1459

1003

{

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

}

1466

1004

int e = errno;

1467

1005

free(decrypted_buffer);

1468

1006

free(buffer);

1469

1007

if(tcp_sd >= 0){

1470

ret = close(tcp_sd);

1008

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

1471

1009

}

1472

1010

if(ret == -1){

1473

1011

if(e == 0){

1485

1023

return retval;

1486

1024

}

1487

1025

1488

__attribute__((nonnull))

1489

1026

static void resolve_callback(AvahiSServiceResolver *r,

1490

1027

AvahiIfIndex interface,

1491

1028

AvahiProtocol proto,

1499

1036

AVAHI_GCC_UNUSED AvahiStringList *txt,

1500

1037

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1501

1038

flags,

1502

void *mc){

1039

void* mc){

1503

1040

if(r == NULL){

1504

1041

return;

1505

1042

}

1508

1045

timed out */

1509

1046

1510

1047

if(quit_now){

1511

avahi_s_service_resolver_free(r);

1512

1048

return;

1513

1049

}

1514

1050

1559

1095

const char *domain,

1560

1096

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1561

1097

flags,

1562

void *mc){

1098

void* mc){

1563

1099

if(b == NULL){

1564

1100

return;

1565

1101

}

1625

1161

errno = old_errno;

1626

1162

}

1627

1163

1628

__attribute__((nonnull, warn_unused_result))

1629

1164

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

1630

1165

int ret;

1631

1166

error_t ret_errno;

1637

1172

errno = ret_errno;

1638

1173

return false;

1639

1174

}

1640

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

1641

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

1175

strcpy(ifr->ifr_name, ifname);

1642

1176

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1643

1177

if(ret == -1){

1644

1178

if(debug){

1651

1185

return true;

1652

1186

}

1653

1187

1654

__attribute__((nonnull, warn_unused_result))

1655

1188

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

1656

1189

1657

1190

/* Reject the loopback device */

1699

1232

* corresponds to an acceptable network device.

1700

1233

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

1701

1234

*/

1702

__attribute__((nonnull, warn_unused_result))

1703

1235

int good_interface(const struct dirent *if_entry){

1704

1236

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

1705

1237

return 0;

1723

1255

/*

1724

1256

* This function determines if a network interface is up.

1725

1257

*/

1726

__attribute__((nonnull, warn_unused_result))

1727

1258

bool interface_is_up(const char *interface){

1728

1259

struct ifreq ifr;

1729

1260

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

1740

1271

/*

1741

1272

* This function determines if a network interface is running

1742

1273

*/

1743

__attribute__((nonnull, warn_unused_result))

1744

1274

bool interface_is_running(const char *interface){

1745

1275

struct ifreq ifr;

1746

1276

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

1754

1284

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

1755

1285

}

1756

1286

1757

__attribute__((nonnull, pure, warn_unused_result))

1758

1287

int notdotentries(const struct dirent *direntry){

1759

1288

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

1760

1289

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

1767

1296

}

1768

1297

1769

1298

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

1770

__attribute__((nonnull, warn_unused_result))

1771

1299

int runnable_hook(const struct dirent *direntry){

1772

1300

int ret;

1773

1301

size_t sret;

1781

1309

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

1782

1310

"abcdefghijklmnopqrstuvwxyz"

1783

1311

"0123456789"

1784

"_.-");

1312

"_-");

1785

1313

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

1786

1314

/* Contains non-allowed characters */

1787

1315

if(debug){

1791

1319

return 0;

1792

1320

}

1793

1321

1794

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

1322

char *fullname = NULL;

1323

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

1324

if(ret < 0){

1325

perror_plus("asprintf");

1326

return 0;

1327

}

1328

1329

ret = stat(fullname, &st);

1795

1330

if(ret == -1){

1796

1331

if(debug){

1797

1332

perror_plus("Could not stat hook");

1821

1356

return 1;

1822

1357

}

1823

1358

1824

__attribute__((nonnull, warn_unused_result))

1825

1359

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1826

1360

mandos_context *mc){

1827

1361

int ret;

1831

1365

1832

1366

while(true){

1833

1367

if(mc->current_server == NULL){

1834

if(debug){

1368

if (debug){

1835

1369

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

1836

1370

" No timeout!\n");

1837

1371

}

1838

1372

ret = avahi_simple_poll_iterate(s, -1);

1839

1373

} else {

1840

if(debug){

1374

if (debug){

1841

1375

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

1842

1376

" it, or wait\n");

1843

1377

}

1860

1394

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

1861

1395

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

1862

1396

1863

if(debug){

1397

if (debug){

1864

1398

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

1865

1399

block_time);

1866

1400

}

1888

1422

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

1889

1423

}

1890

1424

if(ret != 0){

1891

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

1425

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

1892

1426

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

1893

1427

}

1894

1428

}

1895

1429

}

1896

1430

}

1897

1431

1898

__attribute__((nonnull))

1899

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

1432

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

1433

error_t raise_privileges(void){

1434

error_t old_errno = errno;

1435

error_t ret_errno = 0;

1436

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

1437

ret_errno = errno;

1438

perror_plus("seteuid");

1439

}

1440

errno = old_errno;

1441

return ret_errno;

1442

}

1443

1444

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

1445

error_t raise_privileges_permanently(void){

1446

error_t old_errno = errno;

1447

error_t ret_errno = raise_privileges();

1448

if(ret_errno != 0){

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

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

1453

ret_errno = errno;

1454

perror_plus("seteuid");

1455

}

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

1460

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

1461

error_t lower_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

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

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

/* Lower privileges permanently */

1473

error_t lower_privileges_permanently(void){

1474

error_t old_errno = errno;

1475

error_t ret_errno = 0;

1476

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

1477

ret_errno = errno;

1478

perror_plus("setuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

1900

1485

const float delay){

1901

struct dirent **direntries = NULL;

1902

if(hookdir_fd == -1){

1903

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1904

| O_CLOEXEC);

1905

if(hookdir_fd == -1){

1906

if(errno == ENOENT){

1907

if(debug){

1908

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

1909

" found\n", hookdir);

1910

}

1911

} else {

1912

perror_plus("open");

1913

}

1914

return;

1915

}

1916

}

1917

#ifdef __GLIBC__

1918

#if __GLIBC_PREREQ(2, 15)

1919

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

1920

runnable_hook, alphasort);

1921

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

1922

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

1923

alphasort);

1924

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

1925

#else /* not __GLIBC__ */

1926

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

1927

alphasort);

1928

#endif /* not __GLIBC__ */

1486

struct dirent **direntries;

1487

struct dirent *direntry;

1488

int ret;

1489

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

1490

alphasort);

1929

1491

if(numhooks == -1){

1930

perror_plus("scandir");

1931

return;

1932

}

1933

struct dirent *direntry;

1934

int ret;

1935

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

1936

if(devnull == -1){

1937

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

1938

return;

1939

}

1940

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

1941

direntry = direntries[i];

1942

if(debug){

1943

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

1944

direntry->d_name);

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

perror_plus("scandir");

1945

1499

}

1946

pid_t hook_pid = fork();

1947

if(hook_pid == 0){

1948

/* Child */

1949

/* Raise privileges */

1950

errno = raise_privileges_permanently();

1951

if(errno != 0){

1952

perror_plus("Failed to raise privileges");

1953

_exit(EX_NOPERM);

1954

}

1955

/* Set group */

1956

errno = 0;

1957

ret = setgid(0);

1958

if(ret == -1){

1959

perror_plus("setgid");

1960

_exit(EX_NOPERM);

1961

}

1962

/* Reset supplementary groups */

1963

errno = 0;

1964

ret = setgroups(0, NULL);

1965

if(ret == -1){

1966

perror_plus("setgroups");

1967

_exit(EX_NOPERM);

1968

}

1969

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

1970

if(ret == -1){

1971

perror_plus("setenv");

1972

_exit(EX_OSERR);

1973

}

1974

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

1975

if(ret == -1){

1976

perror_plus("setenv");

1977

_exit(EX_OSERR);

1978

}

1979

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

1980

if(ret == -1){

1981

perror_plus("setenv");

1982

_exit(EX_OSERR);

1983

}

1984

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

1985

if(ret == -1){

1986

perror_plus("setenv");

1987

_exit(EX_OSERR);

1988

}

1989

char *delaystring;

1990

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

1991

if(ret == -1){

1500

} else {

1501

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

1502

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

1503

direntry = direntries[i];

1504

char *fullname = NULL;

1505

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

1506

if(ret < 0){

1992

1507

perror_plus("asprintf");

1993

_exit(EX_OSERR);

1994

}

1995

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

1996

if(ret == -1){

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

1997

1566

free(delaystring);

1998

perror_plus("setenv");

1999

_exit(EX_OSERR);

2000

}

2001

free(delaystring);

2002

if(connect_to != NULL){

2003

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

2004

if(ret == -1){

2005

perror_plus("setenv");

2006

_exit(EX_OSERR);

2007

}

2008

}

2009

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

2010

direntry->d_name,

2011

O_RDONLY));

2012

if(hook_fd == -1){

2013

perror_plus("openat");

2014

_exit(EXIT_FAILURE);

2015

}

2016

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

2017

perror_plus("close");

2018

_exit(EXIT_FAILURE);

2019

}

2020

ret = dup2(devnull, STDIN_FILENO);

2021

if(ret == -1){

2022

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

2023

_exit(EX_OSERR);

2024

}

2025

ret = close(devnull);

2026

if(ret == -1){

2027

perror_plus("close");

2028

_exit(EX_OSERR);

2029

}

2030

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2031

if(ret == -1){

2032

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

2033

_exit(EX_OSERR);

2034

}

2035

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

2036

environ) == -1){

2037

perror_plus("fexecve");

2038

_exit(EXIT_FAILURE);

2039

}

2040

} else {

2041

if(hook_pid == -1){

2042

perror_plus("fork");

2043

free(direntry);

2044

continue;

2045

}

2046

int status;

2047

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

2048

perror_plus("waitpid");

2049

free(direntry);

2050

continue;

2051

}

2052

if(WIFEXITED(status)){

2053

if(WEXITSTATUS(status) != 0){

2054

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

2055

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

2056

WEXITSTATUS(status));

2057

free(direntry);

2058

continue;

2059

}

2060

} else if(WIFSIGNALED(status)){

2061

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

2062

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

2063

WTERMSIG(status));

2064

free(direntry);

2065

continue;

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

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

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

2066

1578

} else {

2067

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

2068

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

2069

free(direntry);

2070

continue;

2071

}

2072

}

2073

if(debug){

2074

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

2075

direntry->d_name);

2076

}

2077

free(direntry);

2078

}

2079

free(direntries);

2080

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

2081

perror_plus("close");

2082

} else {

2083

hookdir_fd = -1;

2084

}

2085

close(devnull);

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

return true;

2086

1615

}

2087

1616

2088

__attribute__((nonnull, warn_unused_result))

2089

1617

error_t bring_up_interface(const char *const interface,

2090

1618

const float delay){

1619

int sd = -1;

2091

1620

error_t old_errno = errno;

2092

int ret;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

2093

1623

struct ifreq network;

2094

1624

unsigned int if_index = if_nametoindex(interface);

2095

1625

if(if_index == 0){

2104

1634

}

2105

1635

2106

1636

if(not interface_is_up(interface)){

2107

error_t ret_errno = 0, ioctl_errno = 0;

2108

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

1637

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

2109

1638

ret_errno = errno;

2110

1639

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

2111

1640

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

2112

errno = old_errno;

2113

1641

return ret_errno;

2114

1642

}

2115

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

1643

network.ifr_flags |= IFF_UP;

2116

1644

2117

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

2118

if(sd == -1){

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2119

1647

ret_errno = errno;

2120

1648

perror_plus("socket");

2121

1649

errno = old_errno;

2122

1650

return ret_errno;

2123

1651

}

2124

1652

2125

1653

if(quit_now){

2126

ret = close(sd);

2127

if(ret == -1){

2128

perror_plus("close");

2129

}

1654

close(sd);

2130

1655

errno = old_errno;

2131

1656

return EINTR;

2132

1657

}

2136

1661

interface);

2137

1662

}

2138

1663

2139

/* Raise privileges */

2140

ret_errno = raise_privileges();

2141

if(ret_errno != 0){

2142

errno = ret_errno;

2143

perror_plus("Failed to raise privileges");

2144

}

1664

/* Raise priviliges */

1665

raise_privileges();

2145

1666

2146

1667

#ifdef __linux__

2147

int ret_linux;

2148

bool restore_loglevel = false;

2149

if(ret_errno == 0){

2150

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2151

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

2152

ret_linux = klogctl(8, NULL, 5);

2153

if(ret_linux == -1){

2154

perror_plus("klogctl");

2155

} else {

2156

restore_loglevel = true;

2157

}

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

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

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

perror_plus("klogctl");

2158

1675

}

2159

1676

#endif /* __linux__ */

2160

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

2161

ioctl_errno = errno;

1677

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

1678

ret_errno = errno;

2162

1679

#ifdef __linux__

2163

1680

if(restore_loglevel){

2164

1681

ret_linux = klogctl(7, NULL, 0);

2168

1685

}

2169

1686

#endif /* __linux__ */

2170

1687

2171

/* If raise_privileges() succeeded above */

2172

if(ret_errno == 0){

2173

/* Lower privileges */

2174

ret_errno = lower_privileges();

2175

if(ret_errno != 0){

2176

errno = ret_errno;

2177

perror_plus("Failed to lower privileges");

2178

}

2179

}

1688

/* Lower privileges */

1689

lower_privileges();

2180

1690

2181

1691

/* Close the socket */

2182

ret = close(sd);

1692

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

2183

1693

if(ret == -1){

2184

1694

perror_plus("close");

2185

1695

}

2186

1696

2187

1697

if(ret_setflags == -1){

2188

errno = ioctl_errno;

1698

errno = ret_errno;

2189

1699

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2190

1700

errno = old_errno;

2191

return ioctl_errno;

1701

return ret_errno;

2192

1702

}

2193

1703

} else if(debug){

2194

1704

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

2212

1722

return 0;

2213

1723

}

2214

1724

2215

__attribute__((nonnull, warn_unused_result))

2216

1725

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

2217

1727

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

2218

1730

struct ifreq network;

2219

1731

unsigned int if_index = if_nametoindex(interface);

2220

1732

if(if_index == 0){

2223

1735

return ENXIO;

2224

1736

}

2225

1737

if(interface_is_up(interface)){

2226

error_t ret_errno = 0, ioctl_errno = 0;

2227

1738

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

2228

1739

ret_errno = errno;

2229

1740

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

2230

1741

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

2231

errno = old_errno;

2232

1742

return ret_errno;

2233

1743

}

2234

1744

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

2235

1745

2236

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

2237

if(sd == -1){

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2238

1748

ret_errno = errno;

2239

1749

perror_plus("socket");

2240

1750

errno = old_errno;

2246

1756

interface);

2247

1757

}

2248

1758

2249

/* Raise privileges */

2250

ret_errno = raise_privileges();

2251

if(ret_errno != 0){

2252

errno = ret_errno;

2253

perror_plus("Failed to raise privileges");

2254

}

2255

2256

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

2257

ioctl_errno = errno;

2258

2259

/* If raise_privileges() succeeded above */

2260

if(ret_errno == 0){

2261

/* Lower privileges */

2262

ret_errno = lower_privileges();

2263

if(ret_errno != 0){

2264

errno = ret_errno;

2265

perror_plus("Failed to lower privileges");

2266

}

2267

}

1759

/* Raise priviliges */

1760

raise_privileges();

1761

1762

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

1763

ret_errno = errno;

1764

1765

/* Lower privileges */

1766

lower_privileges();

2268

1767

2269

1768

/* Close the socket */

2270

int ret = close(sd);

1769

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

2271

1770

if(ret == -1){

2272

1771

perror_plus("close");

2273

1772

}

2274

1773

2275

1774

if(ret_setflags == -1){

2276

errno = ioctl_errno;

1775

errno = ret_errno;

2277

1776

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2278

1777

errno = old_errno;

2279

return ioctl_errno;

1778

return ret_errno;

2280

1779

}

2281

1780

} else if(debug){

2282

1781

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

2288

1787

}

2289

1788

2290

1789

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

2291

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

2292

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

2293

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

2294

.current_server = NULL, .interfaces = NULL,

2295

.interfaces_size = 0 };

1790

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

1791

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

1792

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

1793

.interfaces = NULL, .interfaces_size = 0 };

2296

1794

AvahiSServiceBrowser *sb = NULL;

2297

1795

error_t ret_errno;

2298

1796

int ret;

2301

1799

int exitcode = EXIT_SUCCESS;

2302

1800

char *interfaces_to_take_down = NULL;

2303

1801

size_t interfaces_to_take_down_size = 0;

2304

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

2305

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

2306

char *tempdir = NULL;

1802

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

1803

bool tempdir_created = false;

2307

1804

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2308

1805

const char *seckey = PATHDIR "/" SECKEY;

2309

1806

const char *pubkey = PATHDIR "/" PUBKEY;

2310

const char *dh_params_file = NULL;

2311

1807

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

2312

1809

2313

1810

bool gnutls_initialized = false;

2314

1811

bool gpgme_initialized = false;

2366

1863

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

2367

1864

" Diffie-Hellman key exchange",

2368

1865

.group = 2 },

2369

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

2370

.arg = "FILE",

2371

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

2372

" for the Diffie-Hellman key exchange",

2373

.group = 2 },

2374

1866

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

2375

1867

.arg = "STRING",

2376

1868

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

2431

1923

}

2432

1924

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

2433

1925

break;

2434

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

2435

dh_params_file = arg;

2436

break;

2437

1926

case 130: /* --priority */

2438

1927

mc.priority = arg;

2439

1928

break;

2495

1984

goto end;

2496

1985

}

2497

1986

}

2498

1987

2499

1988

{

2500

1989

/* Work around Debian bug #633582:

2501

1990

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

2502

1991

2503

/* Re-raise privileges */

2504

ret_errno = raise_privileges();

2505

if(ret_errno != 0){

2506

errno = ret_errno;

2507

perror_plus("Failed to raise privileges");

2508

} else {

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2509

1994

struct stat st;

2510

1995

2511

1996

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

2525

2010

}

2526

2011

}

2527

2012

}

2528

close(seckey_fd);

2013

TEMP_FAILURE_RETRY(close(seckey_fd));

2529

2014

}

2530

2015

}

2531

2016

2532

2017

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

2533

2018

int pubkey_fd = open(pubkey, O_RDONLY);

2534

2019

if(pubkey_fd == -1){

2546

2031

}

2547

2032

}

2548

2033

}

2549

close(pubkey_fd);

2550

}

2551

}

2552

2553

if(dh_params_file != NULL

2554

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

2555

int dhparams_fd = open(dh_params_file, O_RDONLY);

2556

if(dhparams_fd == -1){

2557

perror_plus("open");

2558

} else {

2559

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

2560

if(ret == -1){

2561

perror_plus("fstat");

2562

} else {

2563

if(S_ISREG(st.st_mode)

2564

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

2565

ret = fchown(dhparams_fd, uid, gid);

2566

if(ret == -1){

2567

perror_plus("fchown");

2568

}

2569

}

2570

}

2571

close(dhparams_fd);

2572

}

2573

}

2574

2034

TEMP_FAILURE_RETRY(close(pubkey_fd));

2035

}

2036

}

2037

2575

2038

/* Lower privileges */

2576

ret_errno = lower_privileges();

2577

if(ret_errno != 0){

2578

errno = ret_errno;

2579

perror_plus("Failed to lower privileges");

2580

}

2039

lower_privileges();

2581

2040

}

2582

2041

}

2583

2042

2607

2066

goto end;

2608

2067

}

2609

2068

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

2610

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

2611

}

2612

run_network_hooks("start", interfaces_hooks != NULL ?

2613

interfaces_hooks : "", delay);

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

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

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2614

2077

}

2615

2078

2616

2079

if(not debug){

2694

2157

2695

2158

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

2696

2159

if(mc.interfaces == NULL){

2697

struct dirent **direntries = NULL;

2160

struct dirent **direntries;

2698

2161

/* Look for any good interfaces */

2699

2162

ret = scandir(sys_class_net, &direntries, good_interface,

2700

2163

alphasort);

2704

2167

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

2705

2168

direntries[i]->d_name);

2706

2169

if(ret_errno != 0){

2707

errno = ret_errno;

2708

2170

perror_plus("argz_add");

2709

free(direntries[i]);

2710

2171

continue;

2711

2172

}

2712

2173

if(debug){

2713

2174

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

2714

2175

direntries[i]->d_name);

2715

2176

}

2716

free(direntries[i]);

2717

2177

}

2718

2178

free(direntries);

2719

2179

} else {

2720

if(ret == 0){

2721

free(direntries);

2722

}

2180

free(direntries);

2723

2181

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

2724

2182

exitcode = EXIT_FAILURE;

2725

2183

goto end;

2748

2206

break;

2749

2207

}

2750

2208

bool interface_was_up = interface_is_up(interface);

2751

errno = bring_up_interface(interface, delay);

2209

ret = bring_up_interface(interface, delay);

2752

2210

if(not interface_was_up){

2753

if(errno != 0){

2754

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

2755

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

2211

if(ret != 0){

2212

errno = ret;

2213

perror_plus("Failed to bring up interface");

2756

2214

} else {

2757

errno = argz_add(&interfaces_to_take_down,

2758

&interfaces_to_take_down_size,

2759

interface);

2760

if(errno != 0){

2761

perror_plus("argz_add");

2762

}

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2763

2218

}

2764

2219

}

2765

2220

}

2781

2236

goto end;

2782

2237

}

2783

2238

2784

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

2239

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

2785

2240

if(ret == -1){

2786

2241

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

2787

2242

exitcode = EX_UNAVAILABLE;

2794

2249

goto end;

2795

2250

}

2796

2251

2797

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

2798

tempdir = mkdtemp(run_tempdir);

2799

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

2800

if(debug){

2801

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

2802

run_tempdir, old_tempdir);

2803

}

2804

tempdir = mkdtemp(old_tempdir);

2805

}

2806

if(tempdir == NULL){

2252

if(mkdtemp(tempdir) == NULL){

2807

2253

perror_plus("mkdtemp");

2808

2254

goto end;

2809

2255

}

2256

tempdir_created = true;

2810

2257

2811

2258

if(quit_now){

2812

2259

goto end;

2887

2334

sleep((unsigned int)retry_interval);

2888

2335

}

2889

2336

2890

if(not quit_now){

2337

if (not quit_now){

2891

2338

exitcode = EXIT_SUCCESS;

2892

2339

}

2893

2340

2948

2395

if(debug){

2949

2396

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

2950

2397

}

2951

2398

2952

2399

ret = avahi_loop_with_timeout(simple_poll,

2953

2400

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

2954

2401

if(debug){

2990

2437

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

2991

2438

while(mc.current_server != NULL){

2992

2439

server *next = mc.current_server->next;

2993

#ifdef __GNUC__

2994

#pragma GCC diagnostic push

2995

#pragma GCC diagnostic ignored "-Wcast-qual"

2996

#endif

2997

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

2998

#ifdef __GNUC__

2999

#pragma GCC diagnostic pop

3000

#endif

3001

2440

free(mc.current_server);

3002

2441

mc.current_server = next;

3003

2442

}

3004

2443

}

3005

2444

3006

/* Re-raise privileges */

2445

/* Re-raise priviliges */

3007

2446

{

3008

ret_errno = raise_privileges();

3009

if(ret_errno != 0){

3010

errno = ret_errno;

3011

perror_plus("Failed to raise privileges");

3012

} else {

3013

3014

/* Run network hooks */

3015

run_network_hooks("stop", interfaces_hooks != NULL ?

3016

interfaces_hooks : "", delay);

3017

3018

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

3019

{

3020

char *interface = NULL;

3021

while((interface=argz_next(interfaces_to_take_down,

3022

interfaces_to_take_down_size,

3023

interface))){

3024

ret_errno = take_down_interface(interface);

3025

if(ret_errno != 0){

3026

errno = ret_errno;

3027

perror_plus("Failed to take down interface");

3028

}

3029

}

3030

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

3031

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

3032

" down\n");

3033

}

3034

}

3035

}

3036

3037

ret_errno = lower_privileges_permanently();

3038

if(ret_errno != 0){

3039

errno = ret_errno;

3040

perror_plus("Failed to lower privileges permanently");

3041

}

2447

raise_privileges();

2448

2449

/* Run network hooks */

2450

run_network_hooks("stop", interfaces_hooks != NULL ?

2451

interfaces_hooks : "", delay);

2452

2453

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

2454

{

2455

char *interface = NULL;

2456

while((interface=argz_next(interfaces_to_take_down,

2457

interfaces_to_take_down_size,

2458

interface))){

2459

ret_errno = take_down_interface(interface);

2460

if(ret_errno != 0){

2461

errno = ret_errno;

2462

perror_plus("Failed to take down interface");

2463

}

2464

}

2465

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

2466

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

2467

" down\n");

2468

}

2469

}

2470

2471

lower_privileges_permanently();

3042

2472

}

3043

2473

3044

2474

free(interfaces_to_take_down);

3045

2475

free(interfaces_hooks);

3046

2476

3047

2477

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

3048

if(tempdir != NULL){

2478

if(tempdir_created){

3049

2479

struct dirent **direntries = NULL;

3050

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

3051

| O_NOFOLLOW

3052

| O_DIRECTORY

3053

| O_PATH));

3054

if(tempdir_fd == -1){

3055

perror_plus("open");

3056

} else {

3057

#ifdef __GLIBC__

3058

#if __GLIBC_PREREQ(2, 15)

3059

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

3060

notdotentries, alphasort);

3061

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

3062

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

3063

alphasort);

3064

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

3065

#else /* not __GLIBC__ */

3066

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

3067

alphasort);

3068

#endif /* not __GLIBC__ */

3069

if(numentries >= 0){

3070

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

3071

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

3072

if(ret == -1){

3073

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

3074

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

3075

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

3076

}

3077

free(direntries[i]);

3078

}

3079

3080

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

3081

free(direntries);

3082

if(numentries == -1){

3083

perror_plus("scandir");

3084

}

3085

ret = rmdir(tempdir);

3086

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

3087

perror_plus("rmdir");

3088

}

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

2484

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

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

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

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

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

2496

strerror(errno));

2497

}

2498

free(fullname);

3089

2499

}

3090

close(tempdir_fd);

2500

}

2501

2502

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

2503

free(direntries);

2504

if (numentries == -1){

2505

perror_plus("scandir");

2506

}

2507

ret = rmdir(tempdir);

2508

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

2509

perror_plus("rmdir");

3091

2510

}

3092

2511

}

3093

2512