/mandos/release : revision 237.7.322

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

_exit(EX_UNAVAILABLE);

958

}

959

close(helperdir_fd);

960

#ifdef __GNUC__

961

#pragma GCC diagnostic push

962

#pragma GCC diagnostic ignored "-Wcast-qual"

963

#endif

964

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

965

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

966

interface, debug ? debug_flag : NULL, NULL },

967

environ) == -1){

968

#ifdef __GNUC__

969

#pragma GCC diagnostic pop

970

#endif

971

perror_plus("fexecve");

972

_exit(EXIT_FAILURE);

973

}

974

}

975

if(pid == -1){

976

perror_plus("fork");

977

return false;

978

}

979

int status;

980

pid_t pret = -1;

981

errno = 0;

982

do {

983

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

984

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

985

int errno_raising = 0;

986

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

987

errno_raising = errno;

988

perror_plus("Failed to raise privileges in order to"

989

" kill helper program");

990

}

991

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

992

perror_plus("kill");

993

}

994

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

995

perror_plus("Failed to lower privileges after killing"

996

" helper program");

997

}

998

return false;

999

}

1000

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

1001

if(pret == -1){

1002

perror_plus("waitpid");

1003

return false;

1004

}

1005

if(WIFEXITED(status)){

1006

if(WEXITSTATUS(status) != 0){

1007

fprintf_plus(stderr, "Error: iprouteadddel exited"

1008

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

1009

return false;

1010

}

1011

return true;

1012

}

1013

if(WIFSIGNALED(status)){

1014

fprintf_plus(stderr, "Error: iprouteadddel died by"

1015

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

1016

return false;

1017

}

1018

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

1019

return false;

1020

}

1021

1022

__attribute__((nonnull, warn_unused_result))

1023

static bool add_local_route(const char *address,

1024

AvahiIfIndex if_index){

1025

if(debug){

1026

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

1027

}

1028

return add_delete_local_route(true, address, if_index);

1029

}

1030

1031

__attribute__((nonnull, warn_unused_result))

1032

static bool delete_local_route(const char *address,

1033

AvahiIfIndex if_index){

1034

if(debug){

1035

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

1036

}

1037

return add_delete_local_route(false, address, if_index);

1038

}

1039

623

1040

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

624

1042

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

625

1043

AvahiIfIndex if_index,

626

1044

int af, mandos_context *mc){

627

1045

int ret, tcp_sd = -1;

628

1046

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1047

struct sockaddr_storage to;

633

1048

char *buffer = NULL;

634

1049

char *decrypted_buffer = NULL;

635

1050

size_t buffer_length = 0;

638

1053

int retval = -1;

639

1054

gnutls_session_t session;

640

1055

int pf; /* Protocol family */

1056

bool route_added = false;

641

1057

642

1058

errno = 0;

643

1059

701

1117

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

702

1118

}

703

1119

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

705

1121

if(tcp_sd < 0){

706

1122

int e = errno;

707

1123

perror_plus("socket");

714

1130

goto mandos_end;

715

1131

}

716

1132

717

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

718

1133

if(af == AF_INET6){

719

to.in6.sin6_family = (sa_family_t)af;

720

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

1134

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

1135

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

1136

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

721

1137

} else { /* IPv4 */

722

to.in.sin_family = (sa_family_t)af;

723

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

1138

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

1139

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

1140

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

724

1141

}

725

1142

if(ret < 0 ){

726

1143

int e = errno;

735

1152

goto mandos_end;

736

1153

}

737

1154

if(af == AF_INET6){

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

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

741

-Wunreachable-code*/

1155

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

1156

if(IN6_IS_ADDR_LINKLOCAL

1157

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

742

1158

if(if_index == AVAHI_IF_UNSPEC){

743

1159

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

744

1160

" incomplete without a network interface\n");

746

1162

goto mandos_end;

747

1163

}

748

1164

/* Set the network interface number as scope */

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

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

750

1166

}

751

1167

} else {

752

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

753

-Wconversion and

754

-Wunreachable-code */

1168

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

755

1169

}

756

1170

757

1171

if(quit_now){

774

1188

}

775

1189

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

776

1190

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

777

const char *pcret;

778

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

781

} else {

782

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

783

sizeof(addrstr));

784

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

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

789

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

790

}

791

}

792

}

793

794

if(quit_now){

795

errno = EINTR;

796

goto mandos_end;

797

}

798

799

if(af == AF_INET6){

800

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

801

} else {

802

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

803

}

804

if(ret < 0){

805

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

806

int e = errno;

807

perror_plus("connect");

808

errno = e;

809

}

810

goto mandos_end;

811

}

812

813

if(quit_now){

814

errno = EINTR;

815

goto mandos_end;

1191

if(af == AF_INET6){

1192

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

1193

sizeof(struct sockaddr_in6),

1194

addrstr, sizeof(addrstr), NULL, 0,

1195

NI_NUMERICHOST);

1196

} else {

1197

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

1198

sizeof(struct sockaddr_in),

1199

addrstr, sizeof(addrstr), NULL, 0,

1200

NI_NUMERICHOST);

1201

}

1202

if(ret == EAI_SYSTEM){

1203

perror_plus("getnameinfo");

1204

} else if(ret != 0) {

1205

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

1206

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

1207

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

1208

}

1209

}

1210

1211

if(quit_now){

1212

errno = EINTR;

1213

goto mandos_end;

1214

}

1215

1216

while(true){

1217

if(af == AF_INET6){

1218

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

1219

sizeof(struct sockaddr_in6));

1220

} else {

1221

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

1222

sizeof(struct sockaddr_in));

1223

}

1224

if(ret < 0){

1225

if(errno == ENETUNREACH

1226

and if_index != AVAHI_IF_UNSPEC

1227

and connect_to == NULL

1228

and not route_added and

1229

((af == AF_INET6 and not

1230

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1231

&to)->sin6_addr)))

1232

or (af == AF_INET and

1233

/* Not a a IPv4LL address */

1234

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

1235

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

1236

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

1237

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

1238

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

1239

connect to a Mandos server announced by Avahi on a server

1240

host with a global address. Work around this by retrying

1241

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

1242

1243

Avahi bug reference:

1244

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

1245

https://bugs.debian.org/587961

1246

*/

1247

if(debug){

1248

fprintf_plus(stderr, "Mandos server unreachable, trying"

1249

" direct route\n");

1250

}

1251

int e = errno;

1252

route_added = add_local_route(ip, if_index);

1253

if(route_added){

1254

continue;

1255

}

1256

errno = e;

1257

}

1258

if(errno != ECONNREFUSED or debug){

1259

int e = errno;

1260

perror_plus("connect");

1261

errno = e;

1262

}

1263

goto mandos_end;

1264

}

1265

1266

if(quit_now){

1267

errno = EINTR;

1268

goto mandos_end;

1269

}

1270

break;

816

1271

}

817

1272

818

1273

const char *out = mandos_protocol_version;

1001

1456

1002

1457

mandos_end:

1003

1458

{

1459

if(route_added){

1460

if(not delete_local_route(ip, if_index)){

1461

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

1462

" interface %d", ip, if_index);

1463

}

1464

}

1004

1465

int e = errno;

1005

1466

free(decrypted_buffer);

1006

1467

free(buffer);

1007

1468

if(tcp_sd >= 0){

1008

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

1469

ret = close(tcp_sd);

1009

1470

}

1010

1471

if(ret == -1){

1011

1472

if(e == 0){

1023

1484

return retval;

1024

1485

}

1025

1486

1487

__attribute__((nonnull))

1026

1488

static void resolve_callback(AvahiSServiceResolver *r,

1027

1489

AvahiIfIndex interface,

1028

1490

AvahiProtocol proto,

1036

1498

AVAHI_GCC_UNUSED AvahiStringList *txt,

1037

1499

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1038

1500

flags,

1039

void* mc){

1501

void *mc){

1040

1502

if(r == NULL){

1041

1503

return;

1042

1504

}

1045

1507

timed out */

1046

1508

1047

1509

if(quit_now){

1510

avahi_s_service_resolver_free(r);

1048

1511

return;

1049

1512

}

1050

1513

1095

1558

const char *domain,

1096

1559

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1097

1560

flags,

1098

void* mc){

1561

void *mc){

1099

1562

if(b == NULL){

1100

1563

return;

1101

1564

}

1161

1624

errno = old_errno;

1162

1625

}

1163

1626

1627

__attribute__((nonnull, warn_unused_result))

1164

1628

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

1165

1629

int ret;

1166

1630

error_t ret_errno;

1185

1649

return true;

1186

1650

}

1187

1651

1652

__attribute__((nonnull, warn_unused_result))

1188

1653

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

1189

1654

1190

1655

/* Reject the loopback device */

1232

1697

* corresponds to an acceptable network device.

1233

1698

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

1234

1699

*/

1700

__attribute__((nonnull, warn_unused_result))

1235

1701

int good_interface(const struct dirent *if_entry){

1236

1702

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

1237

1703

return 0;

1255

1721

/*

1256

1722

* This function determines if a network interface is up.

1257

1723

*/

1724

__attribute__((nonnull, warn_unused_result))

1258

1725

bool interface_is_up(const char *interface){

1259

1726

struct ifreq ifr;

1260

1727

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

1271

1738

/*

1272

1739

* This function determines if a network interface is running

1273

1740

*/

1741

__attribute__((nonnull, warn_unused_result))

1274

1742

bool interface_is_running(const char *interface){

1275

1743

struct ifreq ifr;

1276

1744

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

1284

1752

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

1285

1753

}

1286

1754

1755

__attribute__((nonnull, pure, warn_unused_result))

1287

1756

int notdotentries(const struct dirent *direntry){

1288

1757

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

1289

1758

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

1296

1765

}

1297

1766

1298

1767

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

1768

__attribute__((nonnull, warn_unused_result))

1299

1769

int runnable_hook(const struct dirent *direntry){

1300

1770

int ret;

1301

1771

size_t sret;

1309

1779

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

1310

1780

"abcdefghijklmnopqrstuvwxyz"

1311

1781

"0123456789"

1312

"_-");

1782

"_.-");

1313

1783

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

1314

1784

/* Contains non-allowed characters */

1315

1785

if(debug){

1319

1789

return 0;

1320

1790

}

1321

1791

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);

1792

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

1330

1793

if(ret == -1){

1331

1794

if(debug){

1332

1795

perror_plus("Could not stat hook");

1356

1819

return 1;

1357

1820

}

1358

1821

1822

__attribute__((nonnull, warn_unused_result))

1359

1823

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1360

1824

mandos_context *mc){

1361

1825

int ret;

1365

1829

1366

1830

while(true){

1367

1831

if(mc->current_server == NULL){

1368

if (debug){

1832

if(debug){

1369

1833

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

1370

1834

" No timeout!\n");

1371

1835

}

1372

1836

ret = avahi_simple_poll_iterate(s, -1);

1373

1837

} else {

1374

if (debug){

1838

if(debug){

1375

1839

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

1376

1840

" it, or wait\n");

1377

1841

}

1394

1858

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

1395

1859

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

1396

1860

1397

if (debug){

1861

if(debug){

1398

1862

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

1399

1863

block_time);

1400

1864

}

1422

1886

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

1423

1887

}

1424

1888

if(ret != 0){

1425

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

1889

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

1426

1890

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

1427

1891

}

1428

1892

}

1429

1893

}

1430

1894

}

1431

1895

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,

1896

__attribute__((nonnull))

1897

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

1485

1898

const float delay){

1486

struct dirent **direntries;

1899

struct dirent **direntries = NULL;

1900

if(hookdir_fd == -1){

1901

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1902

| O_CLOEXEC);

1903

if(hookdir_fd == -1){

1904

if(errno == ENOENT){

1905

if(debug){

1906

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

1907

" found\n", hookdir);

1908

}

1909

} else {

1910

perror_plus("open");

1911

}

1912

return;

1913

}

1914

}

1915

#ifdef __GLIBC__

1916

#if __GLIBC_PREREQ(2, 15)

1917

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

1918

runnable_hook, alphasort);

1919

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

1920

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

1921

alphasort);

1922

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

1923

#else /* not __GLIBC__ */

1924

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

1925

alphasort);

1926

#endif /* not __GLIBC__ */

1927

if(numhooks == -1){

1928

perror_plus("scandir");

1929

return;

1930

}

1487

1931

struct dirent *direntry;

1488

1932

int ret;

1489

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

1490

alphasort);

1491

if(numhooks == -1){

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

perror_plus("scandir");

1933

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

1934

if(devnull == -1){

1935

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

1936

return;

1937

}

1938

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

1939

direntry = direntries[i];

1940

if(debug){

1941

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

1942

direntry->d_name);

1499

1943

}

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){

1944

pid_t hook_pid = fork();

1945

if(hook_pid == 0){

1946

/* Child */

1947

/* Raise privileges */

1948

errno = raise_privileges_permanently();

1949

if(errno != 0){

1950

perror_plus("Failed to raise privileges");

1951

_exit(EX_NOPERM);

1952

}

1953

/* Set group */

1954

errno = 0;

1955

ret = setgid(0);

1956

if(ret == -1){

1957

perror_plus("setgid");

1958

_exit(EX_NOPERM);

1959

}

1960

/* Reset supplementary groups */

1961

errno = 0;

1962

ret = setgroups(0, NULL);

1963

if(ret == -1){

1964

perror_plus("setgroups");

1965

_exit(EX_NOPERM);

1966

}

1967

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

1968

if(ret == -1){

1969

perror_plus("setenv");

1970

_exit(EX_OSERR);

1971

}

1972

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

1973

if(ret == -1){

1974

perror_plus("setenv");

1975

_exit(EX_OSERR);

1976

}

1977

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

1978

if(ret == -1){

1979

perror_plus("setenv");

1980

_exit(EX_OSERR);

1981

}

1982

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

1983

if(ret == -1){

1984

perror_plus("setenv");

1985

_exit(EX_OSERR);

1986

}

1987

char *delaystring;

1988

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

1989

if(ret == -1){

1507

1990

perror_plus("asprintf");

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

1991

_exit(EX_OSERR);

1992

}

1993

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

1994

if(ret == -1){

1566

1995

free(delaystring);

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

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

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

1996

perror_plus("setenv");

1997

_exit(EX_OSERR);

1998

}

1999

free(delaystring);

2000

if(connect_to != NULL){

2001

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

2002

if(ret == -1){

2003

perror_plus("setenv");

2004

_exit(EX_OSERR);

2005

}

2006

}

2007

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

2008

direntry->d_name,

2009

O_RDONLY));

2010

if(hook_fd == -1){

2011

perror_plus("openat");

2012

_exit(EXIT_FAILURE);

2013

}

2014

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

2015

perror_plus("close");

2016

_exit(EXIT_FAILURE);

2017

}

2018

ret = dup2(devnull, STDIN_FILENO);

2019

if(ret == -1){

2020

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

2021

_exit(EX_OSERR);

2022

}

2023

ret = close(devnull);

2024

if(ret == -1){

2025

perror_plus("close");

2026

_exit(EX_OSERR);

2027

}

2028

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2029

if(ret == -1){

2030

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

2031

_exit(EX_OSERR);

2032

}

2033

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

2034

environ) == -1){

2035

perror_plus("fexecve");

2036

_exit(EXIT_FAILURE);

2037

}

2038

} else {

2039

if(hook_pid == -1){

2040

perror_plus("fork");

2041

free(direntry);

2042

continue;

2043

}

2044

int status;

2045

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

2046

perror_plus("waitpid");

2047

free(direntry);

2048

continue;

2049

}

2050

if(WIFEXITED(status)){

2051

if(WEXITSTATUS(status) != 0){

2052

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

2053

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

2054

WEXITSTATUS(status));

2055

free(direntry);

2056

continue;

2057

}

2058

} else if(WIFSIGNALED(status)){

2059

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

2060

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

2061

WTERMSIG(status));

2062

free(direntry);

2063

continue;

1578

2064

} else {

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

return true;

2065

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

2066

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

2067

free(direntry);

2068

continue;

2069

}

2070

}

2071

if(debug){

2072

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

2073

direntry->d_name);

2074

}

2075

free(direntry);

2076

}

2077

free(direntries);

2078

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

2079

perror_plus("close");

2080

} else {

2081

hookdir_fd = -1;

2082

}

2083

close(devnull);

1615

2084

}

1616

2085

2086

__attribute__((nonnull, warn_unused_result))

1617

2087

error_t bring_up_interface(const char *const interface,

1618

2088

const float delay){

1619

int sd = -1;

1620

2089

error_t old_errno = errno;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

2090

int ret;

1623

2091

struct ifreq network;

1624

2092

unsigned int if_index = if_nametoindex(interface);

1625

2093

if(if_index == 0){

1634

2102

}

1635

2103

1636

2104

if(not interface_is_up(interface)){

1637

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

2105

error_t ret_errno = 0, ioctl_errno = 0;

2106

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

1638

2107

ret_errno = errno;

1639

2108

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

1640

2109

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

2110

errno = old_errno;

1641

2111

return ret_errno;

1642

2112

}

1643

network.ifr_flags |= IFF_UP;

2113

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

1644

2114

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2115

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

2116

if(sd == -1){

1647

2117

ret_errno = errno;

1648

2118

perror_plus("socket");

1649

2119

errno = old_errno;

1650

2120

return ret_errno;

1651

2121

}

1652

2122

1653

2123

if(quit_now){

1654

close(sd);

2124

ret = close(sd);

2125

if(ret == -1){

2126

perror_plus("close");

2127

}

1655

2128

errno = old_errno;

1656

2129

return EINTR;

1657

2130

}

1661

2134

interface);

1662

2135

}

1663

2136

1664

/* Raise priviliges */

1665

raise_privileges();

2137

/* Raise privileges */

2138

ret_errno = raise_privileges();

2139

if(ret_errno != 0){

2140

errno = ret_errno;

2141

perror_plus("Failed to raise privileges");

2142

}

1666

2143

1667

2144

#ifdef __linux__

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

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

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

perror_plus("klogctl");

2145

int ret_linux;

2146

bool restore_loglevel = false;

2147

if(ret_errno == 0){

2148

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2149

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

2150

ret_linux = klogctl(8, NULL, 5);

2151

if(ret_linux == -1){

2152

perror_plus("klogctl");

2153

} else {

2154

restore_loglevel = true;

2155

}

1675

2156

}

1676

2157

#endif /* __linux__ */

1677

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

1678

ret_errno = errno;

2158

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

2159

ioctl_errno = errno;

1679

2160

#ifdef __linux__

1680

2161

if(restore_loglevel){

1681

2162

ret_linux = klogctl(7, NULL, 0);

1685

2166

}

1686

2167

#endif /* __linux__ */

1687

2168

1688

/* Lower privileges */

1689

lower_privileges();

2169

/* If raise_privileges() succeeded above */

2170

if(ret_errno == 0){

2171

/* Lower privileges */

2172

ret_errno = lower_privileges();

2173

if(ret_errno != 0){

2174

errno = ret_errno;

2175

perror_plus("Failed to lower privileges");

2176

}

2177

}

1690

2178

1691

2179

/* Close the socket */

1692

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

2180

ret = close(sd);

1693

2181

if(ret == -1){

1694

2182

perror_plus("close");

1695

2183

}

1696

2184

1697

2185

if(ret_setflags == -1){

1698

errno = ret_errno;

2186

errno = ioctl_errno;

1699

2187

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1700

2188

errno = old_errno;

1701

return ret_errno;

2189

return ioctl_errno;

1702

2190

}

1703

2191

} else if(debug){

1704

2192

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

1722

2210

return 0;

1723

2211

}

1724

2212

2213

__attribute__((nonnull, warn_unused_result))

1725

2214

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

1727

2215

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

1730

2216

struct ifreq network;

1731

2217

unsigned int if_index = if_nametoindex(interface);

1732

2218

if(if_index == 0){

1735

2221

return ENXIO;

1736

2222

}

1737

2223

if(interface_is_up(interface)){

2224

error_t ret_errno = 0, ioctl_errno = 0;

1738

2225

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

1739

2226

ret_errno = errno;

1740

2227

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

1741

2228

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

2229

errno = old_errno;

1742

2230

return ret_errno;

1743

2231

}

1744

2232

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

1745

2233

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2234

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

2235

if(sd == -1){

1748

2236

ret_errno = errno;

1749

2237

perror_plus("socket");

1750

2238

errno = old_errno;

1756

2244

interface);

1757

2245

}

1758

2246

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();

2247

/* Raise privileges */

2248

ret_errno = raise_privileges();

2249

if(ret_errno != 0){

2250

errno = ret_errno;

2251

perror_plus("Failed to raise privileges");

2252

}

2253

2254

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

2255

ioctl_errno = errno;

2256

2257

/* If raise_privileges() succeeded above */

2258

if(ret_errno == 0){

2259

/* Lower privileges */

2260

ret_errno = lower_privileges();

2261

if(ret_errno != 0){

2262

errno = ret_errno;

2263

perror_plus("Failed to lower privileges");

2264

}

2265

}

1767

2266

1768

2267

/* Close the socket */

1769

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

2268

int ret = close(sd);

1770

2269

if(ret == -1){

1771

2270

perror_plus("close");

1772

2271

}

1773

2272

1774

2273

if(ret_setflags == -1){

1775

errno = ret_errno;

2274

errno = ioctl_errno;

1776

2275

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1777

2276

errno = old_errno;

1778

return ret_errno;

2277

return ioctl_errno;

1779

2278

}

1780

2279

} else if(debug){

1781

2280

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

1787

2286

}

1788

2287

1789

2288

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

1790

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

2289

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

1791

2290

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

1792

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

2291

"+CTYPE-OPENPGP:!RSA", .current_server = NULL,

1793

2292

.interfaces = NULL, .interfaces_size = 0 };

1794

2293

AvahiSServiceBrowser *sb = NULL;

1795

2294

error_t ret_errno;

1799

2298

int exitcode = EXIT_SUCCESS;

1800

2299

char *interfaces_to_take_down = NULL;

1801

2300

size_t interfaces_to_take_down_size = 0;

1802

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

1803

bool tempdir_created = false;

2301

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

2302

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

2303

char *tempdir = NULL;

1804

2304

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1805

2305

const char *seckey = PATHDIR "/" SECKEY;

1806

2306

const char *pubkey = PATHDIR "/" PUBKEY;

2307

const char *dh_params_file = NULL;

1807

2308

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

1809

2309

1810

2310

bool gnutls_initialized = false;

1811

2311

bool gpgme_initialized = false;

1863

2363

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

1864

2364

" Diffie-Hellman key exchange",

1865

2365

.group = 2 },

2366

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

2367

.arg = "FILE",

2368

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

2369

" for the Diffie-Hellman key exchange",

2370

.group = 2 },

1866

2371

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

1867

2372

.arg = "STRING",

1868

2373

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

1923

2428

}

1924

2429

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

1925

2430

break;

2431

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

2432

dh_params_file = arg;

2433

break;

1926

2434

case 130: /* --priority */

1927

2435

mc.priority = arg;

1928

2436

break;

1984

2492

goto end;

1985

2493

}

1986

2494

}

1987

2495

1988

2496

{

1989

2497

/* Work around Debian bug #633582:

1990

2498

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

1991

2499

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2500

/* Re-raise privileges */

2501

ret_errno = raise_privileges();

2502

if(ret_errno != 0){

2503

errno = ret_errno;

2504

perror_plus("Failed to raise privileges");

2505

} else {

1994

2506

struct stat st;

1995

2507

1996

2508

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

2010

2522

}

2011

2523

}

2012

2524

}

2013

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

close(seckey_fd);

2014

2526

}

2015

2527

}

2016

2528

2017

2529

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

2018

2530

int pubkey_fd = open(pubkey, O_RDONLY);

2019

2531

if(pubkey_fd == -1){

2031

2543

}

2032

2544

}

2033

2545

}

2034

TEMP_FAILURE_RETRY(close(pubkey_fd));

2035

}

2036

}

2037

2546

close(pubkey_fd);

2547

}

2548

}

2549

2550

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

2551

int dhparams_fd = open(dh_params_file, O_RDONLY);

2552

if(dhparams_fd == -1){

2553

perror_plus("open");

2554

} else {

2555

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

2556

if(ret == -1){

2557

perror_plus("fstat");

2558

} else {

2559

if(S_ISREG(st.st_mode)

2560

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

2561

ret = fchown(dhparams_fd, uid, gid);

2562

if(ret == -1){

2563

perror_plus("fchown");

2564

}

2565

}

2566

}

2567

close(dhparams_fd);

2568

}

2569

}

2570

2038

2571

/* Lower privileges */

2039

lower_privileges();

2572

ret_errno = lower_privileges();

2573

if(ret_errno != 0){

2574

errno = ret_errno;

2575

perror_plus("Failed to lower privileges");

2576

}

2040

2577

}

2041

2578

}

2042

2579

2066

2603

goto end;

2067

2604

}

2068

2605

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

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

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

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2606

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

2607

}

2608

run_network_hooks("start", interfaces_hooks != NULL ?

2609

interfaces_hooks : "", delay);

2077

2610

}

2078

2611

2079

2612

if(not debug){

2157

2690

2158

2691

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

2159

2692

if(mc.interfaces == NULL){

2160

struct dirent **direntries;

2693

struct dirent **direntries = NULL;

2161

2694

/* Look for any good interfaces */

2162

2695

ret = scandir(sys_class_net, &direntries, good_interface,

2163

2696

alphasort);

2167

2700

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

2168

2701

direntries[i]->d_name);

2169

2702

if(ret_errno != 0){

2703

errno = ret_errno;

2170

2704

perror_plus("argz_add");

2705

free(direntries[i]);

2171

2706

continue;

2172

2707

}

2173

2708

if(debug){

2174

2709

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

2175

2710

direntries[i]->d_name);

2176

2711

}

2712

free(direntries[i]);

2177

2713

}

2178

2714

free(direntries);

2179

2715

} else {

2180

free(direntries);

2716

if(ret == 0){

2717

free(direntries);

2718

}

2181

2719

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

2182

2720

exitcode = EXIT_FAILURE;

2183

2721

goto end;

2206

2744

break;

2207

2745

}

2208

2746

bool interface_was_up = interface_is_up(interface);

2209

ret = bring_up_interface(interface, delay);

2747

errno = bring_up_interface(interface, delay);

2210

2748

if(not interface_was_up){

2211

if(ret != 0){

2212

errno = ret;

2213

perror_plus("Failed to bring up interface");

2749

if(errno != 0){

2750

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

2751

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

2214

2752

} else {

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2753

errno = argz_add(&interfaces_to_take_down,

2754

&interfaces_to_take_down_size,

2755

interface);

2756

if(errno != 0){

2757

perror_plus("argz_add");

2758

}

2218

2759

}

2219

2760

}

2220

2761

}

2236

2777

goto end;

2237

2778

}

2238

2779

2239

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

2780

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

2240

2781

if(ret == -1){

2241

2782

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

2242

2783

exitcode = EX_UNAVAILABLE;

2249

2790

goto end;

2250

2791

}

2251

2792

2252

if(mkdtemp(tempdir) == NULL){

2793

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

2794

tempdir = mkdtemp(run_tempdir);

2795

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

2796

if(debug){

2797

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

2798

run_tempdir, old_tempdir);

2799

}

2800

tempdir = mkdtemp(old_tempdir);

2801

}

2802

if(tempdir == NULL){

2253

2803

perror_plus("mkdtemp");

2254

2804

goto end;

2255

2805

}

2256

tempdir_created = true;

2257

2806

2258

2807

if(quit_now){

2259

2808

goto end;

2334

2883

sleep((unsigned int)retry_interval);

2335

2884

}

2336

2885

2337

if (not quit_now){

2886

if(not quit_now){

2338

2887

exitcode = EXIT_SUCCESS;

2339

2888

}

2340

2889

2395

2944

if(debug){

2396

2945

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

2397

2946

}

2398

2947

2399

2948

ret = avahi_loop_with_timeout(simple_poll,

2400

2949

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

2401

2950

if(debug){

2437

2986

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

2438

2987

while(mc.current_server != NULL){

2439

2988

server *next = mc.current_server->next;

2989

#ifdef __GNUC__

2990

#pragma GCC diagnostic push

2991

#pragma GCC diagnostic ignored "-Wcast-qual"

2992

#endif

2993

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

2994

#ifdef __GNUC__

2995

#pragma GCC diagnostic pop

2996

#endif

2440

2997

free(mc.current_server);

2441

2998

mc.current_server = next;

2442

2999

}

2443

3000

}

2444

3001

2445

/* Re-raise priviliges */

3002

/* Re-raise privileges */

2446

3003

{

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();

3004

ret_errno = raise_privileges();

3005

if(ret_errno != 0){

3006

errno = ret_errno;

3007

perror_plus("Failed to raise privileges");

3008

} else {

3009

3010

/* Run network hooks */

3011

run_network_hooks("stop", interfaces_hooks != NULL ?

3012

interfaces_hooks : "", delay);

3013

3014

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

3015

{

3016

char *interface = NULL;

3017

while((interface=argz_next(interfaces_to_take_down,

3018

interfaces_to_take_down_size,

3019

interface))){

3020

ret_errno = take_down_interface(interface);

3021

if(ret_errno != 0){

3022

errno = ret_errno;

3023

perror_plus("Failed to take down interface");

3024

}

3025

}

3026

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

3027

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

3028

" down\n");

3029

}

3030

}

3031

}

3032

3033

ret_errno = lower_privileges_permanently();

3034

if(ret_errno != 0){

3035

errno = ret_errno;

3036

perror_plus("Failed to lower privileges permanently");

3037

}

2472

3038

}

2473

3039

2474

3040

free(interfaces_to_take_down);

2475

3041

free(interfaces_hooks);

2476

3042

2477

3043

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

2478

if(tempdir_created){

3044

if(tempdir != NULL){

2479

3045

struct dirent **direntries = NULL;

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

2484

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

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

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

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

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

2496

strerror(errno));

2497

}

2498

free(fullname);

3046

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

3047

| O_NOFOLLOW

3048

| O_DIRECTORY

3049

| O_PATH));

3050

if(tempdir_fd == -1){

3051

perror_plus("open");

3052

} else {

3053

#ifdef __GLIBC__

3054

#if __GLIBC_PREREQ(2, 15)

3055

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

3056

notdotentries, alphasort);

3057

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

3058

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

3059

alphasort);

3060

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

3061

#else /* not __GLIBC__ */

3062

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

3063

alphasort);

3064

#endif /* not __GLIBC__ */

3065

if(numentries >= 0){

3066

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

3067

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

3068

if(ret == -1){

3069

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

3070

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

3071

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

3072

}

3073

free(direntries[i]);

3074

}

3075

3076

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

3077

free(direntries);

3078

if(numentries == -1){

3079

perror_plus("scandir");

3080

}

3081

ret = rmdir(tempdir);

3082

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

3083

perror_plus("rmdir");

3084

}

2499

3085

}

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");

3086

close(tempdir_fd);

2510

3087

}

2511

3088

}

2512

3089