/mandos/release : revision 237.7.214

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(),

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){

219

213

}

220

214

221

215

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

222

__attribute__((nonnull, warn_unused_result))

223

216

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

224

217

int af, server **current_server){

225

218

int ret;

234

227

.af = af };

235

228

if(new_server->ip == NULL){

236

229

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

230

return false;

253

231

}

254

232

/* Special case of first server */

256

234

new_server->next = new_server;

257

235

new_server->prev = new_server;

258

236

*current_server = new_server;

237

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

259

238

} else {

260

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

261

239

new_server->next = *current_server;

262

240

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

263

241

new_server->prev->next = new_server;

264

242

(*current_server)->prev = new_server;

265

243

}

244

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

245

if(ret == -1){

246

perror_plus("clock_gettime");

247

return false;

248

}

266

249

return true;

267

250

}

268

251

269

252

/*

270

253

* Initialize GPGME.

271

254

*/

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){

255

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

256

const char *tempdir, mandos_context *mc){

277

257

gpgme_error_t rc;

278

258

gpgme_engine_info_t engine_info;

279

259

280

260

/*

281

261

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

282

262

*/

283

bool import_key(const char * const filename){

263

bool import_key(const char *filename){

284

264

int ret;

285

265

int fd;

286

266

gpgme_data_t pgp_data;

367

347

* Decrypt OpenPGP data.

368

348

* Returns -1 on error

369

349

*/

370

__attribute__((nonnull, warn_unused_result))

371

350

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

351

size_t crypto_size,

373

352

char **plaintext,

493

472

return plaintext_length;

494

473

}

495

474

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){

475

static const char * safer_gnutls_strerror(int value){

505

476

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

477

if(ret == NULL)

478

ret = "(unknown)";

479

return ret;

507

480

}

508

481

509

482

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

483

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

512

484

const char* string){

513

485

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

514

486

}

515

487

516

__attribute__((nonnull, warn_unused_result))

517

488

static int init_gnutls_global(const char *pubkeyfilename,

518

489

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

490

mandos_context *mc){

521

491

int ret;

522

unsigned int uret;

523

492

524

493

if(debug){

525

494

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

576

545

safer_gnutls_strerror(ret));

577

546

goto globalfail;

578

547

}

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

}

548

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

549

if(ret != GNUTLS_E_SUCCESS){

550

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

551

safer_gnutls_strerror(ret));

552

goto globalfail;

553

}

554

751

555

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

752

556

753

557

return 0;

760

564

return -1;

761

565

}

762

566

763

__attribute__((nonnull, warn_unused_result))

764

567

static int init_gnutls_session(gnutls_session_t *session,

765

568

mandos_context *mc){

766

569

int ret;

813

616

/* ignore client certificate if any. */

814

617

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

618

619

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

620

816

621

return 0;

817

622

}

818

623

820

625

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

821

626

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

822

627

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 = (int)TEMP_FAILURE_RETRY(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

TEMP_FAILURE_RETRY(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

1040

628

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

1042

629

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

1043

630

AvahiIfIndex if_index,

1044

631

int af, mandos_context *mc){

1045

632

int ret, tcp_sd = -1;

1046

633

ssize_t sret;

1047

struct sockaddr_storage to;

634

union {

635

struct sockaddr_in in;

636

struct sockaddr_in6 in6;

637

} to;

1048

638

char *buffer = NULL;

1049

639

char *decrypted_buffer = NULL;

1050

640

size_t buffer_length = 0;

1053

643

int retval = -1;

1054

644

gnutls_session_t session;

1055

645

int pf; /* Protocol family */

1056

bool route_added = false;

1057

646

1058

647

errno = 0;

1059

648

1117

706

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

1118

707

}

1119

708

1120

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

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

710

if(tcp_sd < 0){

1122

711

int e = errno;

1123

712

perror_plus("socket");

1132

721

1133

722

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

1134

723

if(af == AF_INET6){

1135

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

1136

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

724

to.in6.sin6_family = (sa_family_t)af;

725

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

1137

726

} else { /* IPv4 */

1138

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

1139

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

727

to.in.sin_family = (sa_family_t)af;

728

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

1140

729

}

1141

730

if(ret < 0 ){

1142

731

int e = errno;

1151

740

goto mandos_end;

1152

741

}

1153

742

if(af == AF_INET6){

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

743

to.in6.sin6_port = htons(port);

744

#ifdef __GNUC__

745

#pragma GCC diagnostic push

746

#pragma GCC diagnostic ignored "-Wstrict-aliasing"

747

#endif

748

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

749

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

750

#ifdef __GNUC__

751

#pragma GCC diagnostic pop

752

#endif

1157

753

if(if_index == AVAHI_IF_UNSPEC){

1158

754

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

1159

755

" incomplete without a network interface\n");

1161

757

goto mandos_end;

1162

758

}

1163

759

/* Set the network interface number as scope */

1164

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

760

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

761

}

1166

762

} else {

1167

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

763

to.in.sin_port = htons(port);

1168

764

}

1169

765

1170

766

if(quit_now){

1187

783

}

1188

784

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1189

785

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1190

if(af == AF_INET6){

1191

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

1192

sizeof(struct sockaddr_in6),

1193

addrstr, sizeof(addrstr), NULL, 0,

1194

NI_NUMERICHOST);

1195

} else {

1196

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

1197

sizeof(struct sockaddr_in),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

}

1201

if(ret == EAI_SYSTEM){

1202

perror_plus("getnameinfo");

1203

} else if(ret != 0) {

1204

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

1205

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

1206

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

1207

}

1208

}

1209

1210

if(quit_now){

1211

errno = EINTR;

1212

goto mandos_end;

1213

}

1214

1215

while(true){

1216

if(af == AF_INET6){

1217

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

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

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

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

if(errno == ENETUNREACH

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

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

1234

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

1235

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

1236

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

1237

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

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

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

1241

1242

Avahi bug reference:

1243

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

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

786

const char *pcret;

787

if(af == AF_INET6){

788

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

789

sizeof(addrstr));

790

} else {

791

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

792

sizeof(addrstr));

793

}

794

if(pcret == NULL){

795

perror_plus("inet_ntop");

796

} else {

797

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

798

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

799

}

800

}

801

}

802

803

if(quit_now){

804

errno = EINTR;

805

goto mandos_end;

806

}

807

808

if(af == AF_INET6){

809

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

810

} else {

811

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

812

}

813

if(ret < 0){

814

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

815

int e = errno;

816

perror_plus("connect");

817

errno = e;

818

}

819

goto mandos_end;

820

}

821

822

if(quit_now){

823

errno = EINTR;

824

goto mandos_end;

1270

825

}

1271

826

1272

827

const char *out = mandos_protocol_version;

1455

1010

1456

1011

mandos_end:

1457

1012

{

1458

if(route_added){

1459

if(not delete_local_route(ip, if_index)){

1460

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

1461

" interface %d", ip, if_index);

1462

}

1463

}

1464

1013

int e = errno;

1465

1014

free(decrypted_buffer);

1466

1015

free(buffer);

1483

1032

return retval;

1484

1033

}

1485

1034

1486

__attribute__((nonnull))

1487

1035

static void resolve_callback(AvahiSServiceResolver *r,

1488

1036

AvahiIfIndex interface,

1489

1037

AvahiProtocol proto,

1497

1045

AVAHI_GCC_UNUSED AvahiStringList *txt,

1498

1046

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1499

1047

flags,

1500

void *mc){

1048

void* mc){

1501

1049

if(r == NULL){

1502

1050

return;

1503

1051

}

1506

1054

timed out */

1507

1055

1508

1056

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1510

1057

return;

1511

1058

}

1512

1059

1557

1104

const char *domain,

1558

1105

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1559

1106

flags,

1560

void *mc){

1107

void* mc){

1561

1108

if(b == NULL){

1562

1109

return;

1563

1110

}

1623

1170

errno = old_errno;

1624

1171

}

1625

1172

1626

__attribute__((nonnull, warn_unused_result))

1627

1173

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

1628

1174

int ret;

1629

1175

error_t ret_errno;

1648

1194

return true;

1649

1195

}

1650

1196

1651

__attribute__((nonnull, warn_unused_result))

1652

1197

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

1653

1198

1654

1199

/* Reject the loopback device */

1696

1241

* corresponds to an acceptable network device.

1697

1242

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

1698

1243

*/

1699

__attribute__((nonnull, warn_unused_result))

1700

1244

int good_interface(const struct dirent *if_entry){

1701

1245

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

1702

1246

return 0;

1720

1264

/*

1721

1265

* This function determines if a network interface is up.

1722

1266

*/

1723

__attribute__((nonnull, warn_unused_result))

1724

1267

bool interface_is_up(const char *interface){

1725

1268

struct ifreq ifr;

1726

1269

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

1737

1280

/*

1738

1281

* This function determines if a network interface is running

1739

1282

*/

1740

__attribute__((nonnull, warn_unused_result))

1741

1283

bool interface_is_running(const char *interface){

1742

1284

struct ifreq ifr;

1743

1285

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

1751

1293

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

1752

1294

}

1753

1295

1754

__attribute__((nonnull, pure, warn_unused_result))

1755

1296

int notdotentries(const struct dirent *direntry){

1756

1297

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

1757

1298

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

1764

1305

}

1765

1306

1766

1307

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

1767

__attribute__((nonnull, warn_unused_result))

1768

1308

int runnable_hook(const struct dirent *direntry){

1769

1309

int ret;

1770

1310

size_t sret;

1778

1318

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

1779

1319

"abcdefghijklmnopqrstuvwxyz"

1780

1320

"0123456789"

1781

"_.-");

1321

"_-");

1782

1322

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

1783

1323

/* Contains non-allowed characters */

1784

1324

if(debug){

1788

1328

return 0;

1789

1329

}

1790

1330

1791

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

1331

char *fullname = NULL;

1332

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

1333

if(ret < 0){

1334

perror_plus("asprintf");

1335

return 0;

1336

}

1337

1338

ret = stat(fullname, &st);

1792

1339

if(ret == -1){

1793

1340

if(debug){

1794

1341

perror_plus("Could not stat hook");

1818

1365

return 1;

1819

1366

}

1820

1367

1821

__attribute__((nonnull, warn_unused_result))

1822

1368

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1823

1369

mandos_context *mc){

1824

1370

int ret;

1828

1374

1829

1375

while(true){

1830

1376

if(mc->current_server == NULL){

1831

if(debug){

1377

if (debug){

1832

1378

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

1833

1379

" No timeout!\n");

1834

1380

}

1835

1381

ret = avahi_simple_poll_iterate(s, -1);

1836

1382

} else {

1837

if(debug){

1383

if (debug){

1838

1384

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

1839

1385

" it, or wait\n");

1840

1386

}

1857

1403

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

1858

1404

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

1859

1405

1860

if(debug){

1406

if (debug){

1861

1407

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

1862

1408

block_time);

1863

1409

}

1885

1431

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

1886

1432

}

1887

1433

if(ret != 0){

1888

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

1434

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

1889

1435

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

1890

1436

}

1891

1437

}

1892

1438

}

1893

1439

}

1894

1440

1895

__attribute__((nonnull))

1896

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

1441

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

1442

error_t raise_privileges(void){

1443

error_t old_errno = errno;

1444

error_t ret_errno = 0;

1445

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

1446

ret_errno = errno;

1447

perror_plus("seteuid");

1448

}

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

1453

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

1454

error_t raise_privileges_permanently(void){

1455

error_t old_errno = errno;

1456

error_t ret_errno = raise_privileges();

1457

if(ret_errno != 0){

1458

errno = old_errno;

1459

return ret_errno;

1460

}

1461

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

1462

ret_errno = errno;

1463

perror_plus("seteuid");

1464

}

1465

errno = old_errno;

1466

return ret_errno;

1467

}

1468

1469

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

1470

error_t lower_privileges(void){

1471

error_t old_errno = errno;

1472

error_t ret_errno = 0;

1473

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

1474

ret_errno = errno;

1475

perror_plus("seteuid");

1476

}

1477

errno = old_errno;

1478

return ret_errno;

1479

}

1480

1481

/* Lower privileges permanently */

1482

error_t lower_privileges_permanently(void){

1483

error_t old_errno = errno;

1484

error_t ret_errno = 0;

1485

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

1486

ret_errno = errno;

1487

perror_plus("setuid");

1488

}

1489

errno = old_errno;

1490

return ret_errno;

1491

}

1492

1493

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

1897

1494

const float delay){

1898

struct dirent **direntries = NULL;

1899

if(hookdir_fd == -1){

1900

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1901

| O_CLOEXEC);

1902

if(hookdir_fd == -1){

1903

if(errno == ENOENT){

1904

if(debug){

1905

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

1906

" found\n", hookdir);

1907

}

1908

} else {

1909

perror_plus("open");

1910

}

1911

return;

1912

}

1913

}

1914

#ifdef __GLIBC__

1915

#if __GLIBC_PREREQ(2, 15)

1916

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

1917

runnable_hook, alphasort);

1918

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

1919

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

1920

alphasort);

1921

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

1922

#else /* not __GLIBC__ */

1923

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

1924

alphasort);

1925

#endif /* not __GLIBC__ */

1495

struct dirent **direntries;

1496

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

1497

alphasort);

1926

1498

if(numhooks == -1){

1927

perror_plus("scandir");

1928

return;

1929

}

1930

struct dirent *direntry;

1931

int ret;

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1937

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

1938

direntry = direntries[i];

1939

if(debug){

1940

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

1941

direntry->d_name);

1499

if(errno == ENOENT){

1500

if(debug){

1501

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

1502

" found\n", hookdir);

1503

}

1504

} else {

1505

perror_plus("scandir");

1942

1506

}

1943

pid_t hook_pid = fork();

1944

if(hook_pid == 0){

1945

/* Child */

1946

/* Raise privileges */

1947

errno = raise_privileges_permanently();

1948

if(errno != 0){

1949

perror_plus("Failed to raise privileges");

1950

_exit(EX_NOPERM);

1951

}

1952

/* Set group */

1953

errno = 0;

1954

ret = setgid(0);

1955

if(ret == -1){

1956

perror_plus("setgid");

1957

_exit(EX_NOPERM);

1958

}

1959

/* Reset supplementary groups */

1960

errno = 0;

1961

ret = setgroups(0, NULL);

1962

if(ret == -1){

1963

perror_plus("setgroups");

1964

_exit(EX_NOPERM);

1965

}

1966

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

1967

if(ret == -1){

1968

perror_plus("setenv");

1969

_exit(EX_OSERR);

1970

}

1971

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

1972

if(ret == -1){

1973

perror_plus("setenv");

1974

_exit(EX_OSERR);

1975

}

1976

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

1977

if(ret == -1){

1978

perror_plus("setenv");

1979

_exit(EX_OSERR);

1980

}

1981

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

1982

if(ret == -1){

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

char *delaystring;

1987

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

1988

if(ret == -1){

1507

} else {

1508

struct dirent *direntry;

1509

int ret;

1510

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

1511

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

1512

direntry = direntries[i];

1513

char *fullname = NULL;

1514

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

1515

if(ret < 0){

1989

1516

perror_plus("asprintf");

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1517

continue;

1518

}

1519

if(debug){

1520

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

1521

direntry->d_name);

1522

}

1523

pid_t hook_pid = fork();

1524

if(hook_pid == 0){

1525

/* Child */

1526

/* Raise privileges */

1527

raise_privileges_permanently();

1528

/* Set group */

1529

errno = 0;

1530

ret = setgid(0);

1531

if(ret == -1){

1532

perror_plus("setgid");

1533

}

1534

/* Reset supplementary groups */

1535

errno = 0;

1536

ret = setgroups(0, NULL);

1537

if(ret == -1){

1538

perror_plus("setgroups");

1539

}

1540

dup2(devnull, STDIN_FILENO);

1541

close(devnull);

1542

dup2(STDERR_FILENO, STDOUT_FILENO);

1543

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

1544

if(ret == -1){

1545

perror_plus("setenv");

1546

_exit(EX_OSERR);

1547

}

1548

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

1549

if(ret == -1){

1550

perror_plus("setenv");

1551

_exit(EX_OSERR);

1552

}

1553

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

1554

if(ret == -1){

1555

perror_plus("setenv");

1556

_exit(EX_OSERR);

1557

}

1558

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

1559

if(ret == -1){

1560

perror_plus("setenv");

1561

_exit(EX_OSERR);

1562

}

1563

char *delaystring;

1564

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

1565

if(ret == -1){

1566

perror_plus("asprintf");

1567

_exit(EX_OSERR);

1568

}

1569

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

1570

if(ret == -1){

1571

free(delaystring);

1572

perror_plus("setenv");

1573

_exit(EX_OSERR);

1574

}

1994

1575

free(delaystring);

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

free(delaystring);

1999

if(connect_to != NULL){

2000

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

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

}

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

2009

if(hook_fd == -1){

2010

perror_plus("openat");

2011

_exit(EXIT_FAILURE);

2012

}

2013

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

2014

perror_plus("close");

2015

_exit(EXIT_FAILURE);

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

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

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

2032

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

2033

environ) == -1){

2034

perror_plus("fexecve");

2035

_exit(EXIT_FAILURE);

2036

}

2037

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

int status;

2044

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

2045

perror_plus("waitpid");

2046

free(direntry);

2047

continue;

2048

}

2049

if(WIFEXITED(status)){

2050

if(WEXITSTATUS(status) != 0){

2051

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

2052

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

2053

WEXITSTATUS(status));

2054

free(direntry);

2055

continue;

2056

}

2057

} else if(WIFSIGNALED(status)){

2058

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

2059

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

2060

WTERMSIG(status));

2061

free(direntry);

2062

continue;

1576

if(connect_to != NULL){

1577

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

1578

if(ret == -1){

1579

perror_plus("setenv");

1580

_exit(EX_OSERR);

1581

}

1582

}

1583

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

1584

perror_plus("execl");

1585

_exit(EXIT_FAILURE);

1586

}

2063

1587

} else {

2064

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

2065

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

2066

free(direntry);

2067

continue;

2068

}

2069

}

2070

if(debug){

2071

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

2072

direntry->d_name);

2073

}

2074

free(direntry);

2075

}

2076

free(direntries);

2077

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

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

1588

int status;

1589

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

1590

perror_plus("waitpid");

1591

free(fullname);

1592

continue;

1593

}

1594

if(WIFEXITED(status)){

1595

if(WEXITSTATUS(status) != 0){

1596

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

1597

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

1598

WEXITSTATUS(status));

1599

free(fullname);

1600

continue;

1601

}

1602

} else if(WIFSIGNALED(status)){

1603

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

1604

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

1605

WTERMSIG(status));

1606

free(fullname);

1607

continue;

1608

} else {

1609

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

1610

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

1611

free(fullname);

1612

continue;

1613

}

1614

}

1615

free(fullname);

1616

if(debug){

1617

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

1618

direntry->d_name);

1619

}

1620

}

1621

close(devnull);

1622

}

1623

return true;

2083

1624

}

2084

1625

2085

__attribute__((nonnull, warn_unused_result))

2086

1626

error_t bring_up_interface(const char *const interface,

2087

1627

const float delay){

1628

int sd = -1;

2088

1629

error_t old_errno = errno;

2089

int ret;

1630

error_t ret_errno = 0;

1631

int ret, ret_setflags;

2090

1632

struct ifreq network;

2091

1633

unsigned int if_index = if_nametoindex(interface);

2092

1634

if(if_index == 0){

2101

1643

}

2102

1644

2103

1645

if(not interface_is_up(interface)){

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

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

1646

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

2106

1647

ret_errno = errno;

2107

1648

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

2108

1649

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

2109

errno = old_errno;

2110

1650

return ret_errno;

2111

1651

}

2112

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

1652

network.ifr_flags |= IFF_UP;

2113

1653

2114

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

2115

if(sd == -1){

1654

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1655

if(sd < 0){

2116

1656

ret_errno = errno;

2117

1657

perror_plus("socket");

2118

1658

errno = old_errno;

2119

1659

return ret_errno;

2120

1660

}

2121

1661

2122

1662

if(quit_now){

2123

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

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

1663

close(sd);

2127

1664

errno = old_errno;

2128

1665

return EINTR;

2129

1666

}

2133

1670

interface);

2134

1671

}

2135

1672

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

1673

/* Raise priviliges */

1674

raise_privileges();

2142

1675

2143

1676

#ifdef __linux__

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

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

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

1677

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1678

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

1679

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

1680

bool restore_loglevel = true;

1681

if(ret_linux == -1){

1682

restore_loglevel = false;

1683

perror_plus("klogctl");

2155

1684

}

2156

1685

#endif /* __linux__ */

2157

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

2158

ioctl_errno = errno;

1686

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

1687

ret_errno = errno;

2159

1688

#ifdef __linux__

2160

1689

if(restore_loglevel){

2161

1690

ret_linux = klogctl(7, NULL, 0);

2165

1694

}

2166

1695

#endif /* __linux__ */

2167

1696

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

1697

/* Lower privileges */

1698

lower_privileges();

2177

1699

2178

1700

/* Close the socket */

2179

1701

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

2182

1704

}

2183

1705

2184

1706

if(ret_setflags == -1){

2185

errno = ioctl_errno;

1707

errno = ret_errno;

2186

1708

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2187

1709

errno = old_errno;

2188

return ioctl_errno;

1710

return ret_errno;

2189

1711

}

2190

1712

} else if(debug){

2191

1713

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

2209

1731

return 0;

2210

1732

}

2211

1733

2212

__attribute__((nonnull, warn_unused_result))

2213

1734

error_t take_down_interface(const char *const interface){

2214

1735

error_t old_errno = errno;

2215

1736

struct ifreq network;

2220

1741

return ENXIO;

2221

1742

}

2222

1743

if(interface_is_up(interface)){

2223

error_t ret_errno = 0, ioctl_errno = 0;

1744

error_t ret_errno = 0;

2224

1745

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

2225

1746

ret_errno = errno;

2226

1747

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

2227

1748

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

2228

errno = old_errno;

2229

1749

return ret_errno;

2230

1750

}

2231

1751

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

2232

1752

2233

1753

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

2234

if(sd == -1){

1754

if(sd < 0){

2235

1755

ret_errno = errno;

2236

1756

perror_plus("socket");

2237

1757

errno = old_errno;

2243

1763

interface);

2244

1764

}

2245

1765

2246

/* Raise privileges */

2247

ret_errno = raise_privileges();

2248

if(ret_errno != 0){

2249

errno = ret_errno;

2250

perror_plus("Failed to raise privileges");

2251

}

1766

/* Raise priviliges */

1767

raise_privileges();

2252

1768

2253

1769

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

2254

ioctl_errno = errno;

1770

ret_errno = errno;

2255

1771

2256

/* If raise_privileges() succeeded above */

2257

if(ret_errno == 0){

2258

/* Lower privileges */

2259

ret_errno = lower_privileges();

2260

if(ret_errno != 0){

2261

errno = ret_errno;

2262

perror_plus("Failed to lower privileges");

2263

}

2264

}

1772

/* Lower privileges */

1773

lower_privileges();

2265

1774

2266

1775

/* Close the socket */

2267

1776

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

2270

1779

}

2271

1780

2272

1781

if(ret_setflags == -1){

2273

errno = ioctl_errno;

1782

errno = ret_errno;

2274

1783

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2275

1784

errno = old_errno;

2276

return ioctl_errno;

1785

return ret_errno;

2277

1786

}

2278

1787

} else if(debug){

2279

1788

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

2285

1794

}

2286

1795

2287

1796

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

2288

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

1797

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

2289

1798

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

2290

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

1799

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

2291

1800

.interfaces = NULL, .interfaces_size = 0 };

2292

1801

AvahiSServiceBrowser *sb = NULL;

2293

1802

error_t ret_errno;

2297

1806

int exitcode = EXIT_SUCCESS;

2298

1807

char *interfaces_to_take_down = NULL;

2299

1808

size_t interfaces_to_take_down_size = 0;

2300

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

2301

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

2302

char *tempdir = NULL;

1809

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

1810

bool tempdir_created = false;

2303

1811

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2304

1812

const char *seckey = PATHDIR "/" SECKEY;

2305

1813

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

1814

char *interfaces_hooks = NULL;

2308

1815

2309

1816

bool gnutls_initialized = false;

2362

1869

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

2363

1870

" Diffie-Hellman key exchange",

2364

1871

.group = 2 },

2365

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

2366

.arg = "FILE",

2367

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

2368

" for the Diffie-Hellman key exchange",

2369

.group = 2 },

2370

1872

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

2371

1873

.arg = "STRING",

2372

1874

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

2427

1929

}

2428

1930

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

2429

1931

break;

2430

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

2431

dh_params_file = arg;

2432

break;

2433

1932

case 130: /* --priority */

2434

1933

mc.priority = arg;

2435

1934

break;

2491

1990

goto end;

2492

1991

}

2493

1992

}

2494

1993

2495

1994

{

2496

1995

/* Work around Debian bug #633582:

2497

1996

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

2498

1997

2499

/* Re-raise privileges */

2500

ret_errno = raise_privileges();

2501

if(ret_errno != 0){

2502

errno = ret_errno;

2503

perror_plus("Failed to raise privileges");

2504

} else {

1998

/* Re-raise priviliges */

1999

if(raise_privileges() == 0){

2505

2000

struct stat st;

2506

2001

2507

2002

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

2524

2019

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

2020

}

2526

2021

}

2527

2022

2528

2023

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

2529

2024

int pubkey_fd = open(pubkey, O_RDONLY);

2530

2025

if(pubkey_fd == -1){

2545

2040

TEMP_FAILURE_RETRY(close(pubkey_fd));

2546

2041

}

2547

2042

}

2548

2549

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

2550

int dhparams_fd = open(dh_params_file, O_RDONLY);

2551

if(dhparams_fd == -1){

2552

perror_plus("open");

2553

} else {

2554

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

2555

if(ret == -1){

2556

perror_plus("fstat");

2557

} else {

2558

if(S_ISREG(st.st_mode)

2559

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

2560

ret = fchown(dhparams_fd, uid, gid);

2561

if(ret == -1){

2562

perror_plus("fchown");

2563

}

2564

}

2565

}

2566

TEMP_FAILURE_RETRY(close(dhparams_fd));

2567

}

2568

}

2569

2043

2570

2044

/* Lower privileges */

2571

ret_errno = lower_privileges();

2572

if(ret_errno != 0){

2573

errno = ret_errno;

2574

perror_plus("Failed to lower privileges");

2575

}

2045

lower_privileges();

2576

2046

}

2577

2047

}

2578

2048

2604

2074

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

2605

2075

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

2606

2076

}

2607

run_network_hooks("start", interfaces_hooks != NULL ?

2608

interfaces_hooks : "", delay);

2077

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

2078

interfaces_hooks : "", delay)){

2079

goto end;

2080

}

2609

2081

}

2610

2082

2611

2083

if(not debug){

2689

2161

2690

2162

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

2691

2163

if(mc.interfaces == NULL){

2692

struct dirent **direntries = NULL;

2164

struct dirent **direntries;

2693

2165

/* Look for any good interfaces */

2694

2166

ret = scandir(sys_class_net, &direntries, good_interface,

2695

2167

alphasort);

2701

2173

if(ret_errno != 0){

2702

2174

errno = ret_errno;

2703

2175

perror_plus("argz_add");

2704

free(direntries[i]);

2705

2176

continue;

2706

2177

}

2707

2178

if(debug){

2708

2179

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

2709

2180

direntries[i]->d_name);

2710

2181

}

2711

free(direntries[i]);

2712

2182

}

2713

2183

free(direntries);

2714

2184

} else {

2715

if(ret == 0){

2716

free(direntries);

2717

}

2185

free(direntries);

2718

2186

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

2719

2187

exitcode = EXIT_FAILURE;

2720

2188

goto end;

2743

2211

break;

2744

2212

}

2745

2213

bool interface_was_up = interface_is_up(interface);

2746

errno = bring_up_interface(interface, delay);

2214

ret = bring_up_interface(interface, delay);

2747

2215

if(not interface_was_up){

2748

if(errno != 0){

2749

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

2750

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

2216

if(ret != 0){

2217

errno = ret;

2218

perror_plus("Failed to bring up interface");

2751

2219

} else {

2752

errno = argz_add(&interfaces_to_take_down,

2753

&interfaces_to_take_down_size,

2754

interface);

2755

if(errno != 0){

2220

ret_errno = argz_add(&interfaces_to_take_down,

2221

&interfaces_to_take_down_size,

2222

interface);

2223

if(ret_errno != 0){

2224

errno = ret_errno;

2756

2225

perror_plus("argz_add");

2757

2226

}

2758

2227

}

2776

2245

goto end;

2777

2246

}

2778

2247

2779

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

2248

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

2780

2249

if(ret == -1){

2781

2250

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

2782

2251

exitcode = EX_UNAVAILABLE;

2789

2258

goto end;

2790

2259

}

2791

2260

2792

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

2793

tempdir = mkdtemp(run_tempdir);

2794

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

2795

if(debug){

2796

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

2797

run_tempdir, old_tempdir);

2798

}

2799

tempdir = mkdtemp(old_tempdir);

2800

}

2801

if(tempdir == NULL){

2261

if(mkdtemp(tempdir) == NULL){

2802

2262

perror_plus("mkdtemp");

2803

2263

goto end;

2804

2264

}

2265

tempdir_created = true;

2805

2266

2806

2267

if(quit_now){

2807

2268

goto end;

2882

2343

sleep((unsigned int)retry_interval);

2883

2344

}

2884

2345

2885

if(not quit_now){

2346

if (not quit_now){

2886

2347

exitcode = EXIT_SUCCESS;

2887

2348

}

2888

2349

2943

2404

if(debug){

2944

2405

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

2945

2406

}

2946

2407

2947

2408

ret = avahi_loop_with_timeout(simple_poll,

2948

2409

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

2949

2410

if(debug){

2985

2446

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

2986

2447

while(mc.current_server != NULL){

2987

2448

server *next = mc.current_server->next;

2988

#ifdef __GNUC__

2989

#pragma GCC diagnostic push

2990

#pragma GCC diagnostic ignored "-Wcast-qual"

2991

#endif

2992

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

2993

#ifdef __GNUC__

2994

#pragma GCC diagnostic pop

2995

#endif

2996

2449

free(mc.current_server);

2997

2450

mc.current_server = next;

2998

2451

}

2999

2452

}

3000

2453

3001

/* Re-raise privileges */

2454

/* Re-raise priviliges */

3002

2455

{

3003

ret_errno = raise_privileges();

3004

if(ret_errno != 0){

3005

errno = ret_errno;

3006

perror_plus("Failed to raise privileges");

3007

} else {

3008

3009

/* Run network hooks */

3010

run_network_hooks("stop", interfaces_hooks != NULL ?

3011

interfaces_hooks : "", delay);

3012

3013

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

3014

{

3015

char *interface = NULL;

3016

while((interface=argz_next(interfaces_to_take_down,

3017

interfaces_to_take_down_size,

3018

interface))){

3019

ret_errno = take_down_interface(interface);

3020

if(ret_errno != 0){

3021

errno = ret_errno;

3022

perror_plus("Failed to take down interface");

3023

}

3024

}

3025

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

3026

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

3027

" down\n");

3028

}

3029

}

3030

}

3031

3032

ret_errno = lower_privileges_permanently();

3033

if(ret_errno != 0){

3034

errno = ret_errno;

3035

perror_plus("Failed to lower privileges permanently");

3036

}

2456

raise_privileges();

2457

2458

/* Run network hooks */

2459

run_network_hooks("stop", interfaces_hooks != NULL ?

2460

interfaces_hooks : "", delay);

2461

2462

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

2463

{

2464

char *interface = NULL;

2465

while((interface=argz_next(interfaces_to_take_down,

2466

interfaces_to_take_down_size,

2467

interface))){

2468

ret_errno = take_down_interface(interface);

2469

if(ret_errno != 0){

2470

errno = ret_errno;

2471

perror_plus("Failed to take down interface");

2472

}

2473

}

2474

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

2475

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

2476

" down\n");

2477

}

2478

}

2479

2480

lower_privileges_permanently();

3037

2481

}

3038

2482

3039

2483

free(interfaces_to_take_down);

3040

2484

free(interfaces_hooks);

3041

2485

3042

2486

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

3043

if(tempdir != NULL){

2487

if(tempdir_created){

3044

2488

struct dirent **direntries = NULL;

3045

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

3046

| O_NOFOLLOW

3047

| O_DIRECTORY

3048

| O_PATH));

3049

if(tempdir_fd == -1){

3050

perror_plus("open");

3051

} else {

3052

#ifdef __GLIBC__

3053

#if __GLIBC_PREREQ(2, 15)

3054

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

3055

notdotentries, alphasort);

3056

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

3057

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

3058

alphasort);

3059

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

3060

#else /* not __GLIBC__ */

3061

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

3062

alphasort);

3063

#endif /* not __GLIBC__ */

3064

if(numentries >= 0){

3065

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

3066

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

3067

if(ret == -1){

3068

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

3069

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

3070

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

3071

}

3072

free(direntries[i]);

3073

}

3074

3075

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

3076

free(direntries);

3077

if(numentries == -1){

3078

perror_plus("scandir");

3079

}

3080

ret = rmdir(tempdir);

3081

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

3082

perror_plus("rmdir");

3083

}

2489

struct dirent *direntry = NULL;

2490

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

2491

alphasort);

2492

if (numentries > 0){

2493

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

2494

direntry = direntries[i];

2495

char *fullname = NULL;

2496

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

2497

direntry->d_name);

2498

if(ret < 0){

2499

perror_plus("asprintf");

2500

continue;

2501

}

2502

ret = remove(fullname);

2503

if(ret == -1){

2504

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

2505

strerror(errno));

2506

}

2507

free(fullname);

3084

2508

}

3085

TEMP_FAILURE_RETRY(close(tempdir_fd));

2509

}

2510

2511

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

2512

free(direntries);

2513

if (numentries == -1){

2514

perror_plus("scandir");

2515

}

2516

ret = rmdir(tempdir);

2517

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

2518

perror_plus("rmdir");

3086

2519

}

3087

2520

}

3088

2521