/mandos/release : revision 237.7.320

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(),

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;

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 = (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

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");

716

1132

717

1133

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

718

1134

if(af == AF_INET6){

719

to.in6.sin6_family = (sa_family_t)af;

720

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

1135

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

1136

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

1139

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

724

1140

}

725

1141

if(ret < 0 ){

726

1142

int e = errno;

735

1151

goto mandos_end;

736

1152

}

737

1153

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*/

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

742

1157

if(if_index == AVAHI_IF_UNSPEC){

743

1158

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

744

1159

" incomplete without a network interface\n");

746

1161

goto mandos_end;

747

1162

}

748

1163

/* Set the network interface number as scope */

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1164

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

750

1165

}

751

1166

} else {

752

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

753

-Wconversion and

754

-Wunreachable-code */

1167

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

755

1168

}

756

1169

757

1170

if(quit_now){

774

1187

}

775

1188

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

776

1189

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;

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;

816

1270

}

817

1271

818

1272

const char *out = mandos_protocol_version;

1001

1455

1002

1456

mandos_end:

1003

1457

{

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

}

1004

1464

int e = errno;

1005

1465

free(decrypted_buffer);

1006

1466

free(buffer);

1023

1483

return retval;

1024

1484

}

1025

1485

1486

__attribute__((nonnull))

1026

1487

static void resolve_callback(AvahiSServiceResolver *r,

1027

1488

AvahiIfIndex interface,

1028

1489

AvahiProtocol proto,

1036

1497

AVAHI_GCC_UNUSED AvahiStringList *txt,

1037

1498

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1038

1499

flags,

1039

void* mc){

1500

void *mc){

1040

1501

if(r == NULL){

1041

1502

return;

1042

1503

}

1045

1506

timed out */

1046

1507

1047

1508

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1048

1510

return;

1049

1511

}

1050

1512

1095

1557

const char *domain,

1096

1558

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1097

1559

flags,

1098

void* mc){

1560

void *mc){

1099

1561

if(b == NULL){

1100

1562

return;

1101

1563

}

1161

1623

errno = old_errno;

1162

1624

}

1163

1625

1626

__attribute__((nonnull, warn_unused_result))

1164

1627

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

1165

1628

int ret;

1166

1629

error_t ret_errno;

1185

1648

return true;

1186

1649

}

1187

1650

1651

__attribute__((nonnull, warn_unused_result))

1188

1652

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

1189

1653

1190

1654

/* Reject the loopback device */

1232

1696

* corresponds to an acceptable network device.

1233

1697

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

1234

1698

*/

1699

__attribute__((nonnull, warn_unused_result))

1235

1700

int good_interface(const struct dirent *if_entry){

1236

1701

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

1237

1702

return 0;

1255

1720

/*

1256

1721

* This function determines if a network interface is up.

1257

1722

*/

1723

__attribute__((nonnull, warn_unused_result))

1258

1724

bool interface_is_up(const char *interface){

1259

1725

struct ifreq ifr;

1260

1726

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

1271

1737

/*

1272

1738

* This function determines if a network interface is running

1273

1739

*/

1740

__attribute__((nonnull, warn_unused_result))

1274

1741

bool interface_is_running(const char *interface){

1275

1742

struct ifreq ifr;

1276

1743

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

1284

1751

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

1285

1752

}

1286

1753

1754

__attribute__((nonnull, pure, warn_unused_result))

1287

1755

int notdotentries(const struct dirent *direntry){

1288

1756

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

1289

1757

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

1296

1764

}

1297

1765

1298

1766

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

1767

__attribute__((nonnull, warn_unused_result))

1299

1768

int runnable_hook(const struct dirent *direntry){

1300

1769

int ret;

1301

1770

size_t sret;

1309

1778

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

1310

1779

"abcdefghijklmnopqrstuvwxyz"

1311

1780

"0123456789"

1312

"_-");

1781

"_.-");

1313

1782

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

1314

1783

/* Contains non-allowed characters */

1315

1784

if(debug){

1319

1788

return 0;

1320

1789

}

1321

1790

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);

1791

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

1330

1792

if(ret == -1){

1331

1793

if(debug){

1332

1794

perror_plus("Could not stat hook");

1356

1818

return 1;

1357

1819

}

1358

1820

1821

__attribute__((nonnull, warn_unused_result))

1359

1822

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1360

1823

mandos_context *mc){

1361

1824

int ret;

1365

1828

1366

1829

while(true){

1367

1830

if(mc->current_server == NULL){

1368

if (debug){

1831

if(debug){

1369

1832

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

1370

1833

" No timeout!\n");

1371

1834

}

1372

1835

ret = avahi_simple_poll_iterate(s, -1);

1373

1836

} else {

1374

if (debug){

1837

if(debug){

1375

1838

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

1376

1839

" it, or wait\n");

1377

1840

}

1394

1857

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

1395

1858

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

1396

1859

1397

if (debug){

1860

if(debug){

1398

1861

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

1399

1862

block_time);

1400

1863

}

1422

1885

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

1423

1886

}

1424

1887

if(ret != 0){

1425

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

1888

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

1426

1889

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

1427

1890

}

1428

1891

}

1429

1892

}

1430

1893

}

1431

1894

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,

1895

__attribute__((nonnull))

1896

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

1485

1897

const float delay){

1486

struct dirent **direntries;

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__ */

1926

if(numhooks == -1){

1927

perror_plus("scandir");

1928

return;

1929

}

1487

1930

struct dirent *direntry;

1488

1931

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");

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

1942

}

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){

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

1989

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

}

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1566

1994

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

}

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;

1578

2063

} 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;

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);

1615

2083

}

1616

2084

2085

__attribute__((nonnull, warn_unused_result))

1617

2086

error_t bring_up_interface(const char *const interface,

1618

2087

const float delay){

1619

int sd = -1;

1620

2088

error_t old_errno = errno;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

2089

int ret;

1623

2090

struct ifreq network;

1624

2091

unsigned int if_index = if_nametoindex(interface);

1625

2092

if(if_index == 0){

1634

2101

}

1635

2102

1636

2103

if(not interface_is_up(interface)){

1637

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

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

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

1638

2106

ret_errno = errno;

1639

2107

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

1640

2108

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

2109

errno = old_errno;

1641

2110

return ret_errno;

1642

2111

}

1643

network.ifr_flags |= IFF_UP;

2112

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

1644

2113

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2114

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

2115

if(sd == -1){

1647

2116

ret_errno = errno;

1648

2117

perror_plus("socket");

1649

2118

errno = old_errno;

1650

2119

return ret_errno;

1651

2120

}

1652

2121

1653

2122

if(quit_now){

1654

close(sd);

2123

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

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

1655

2127

errno = old_errno;

1656

2128

return EINTR;

1657

2129

}

1661

2133

interface);

1662

2134

}

1663

2135

1664

/* Raise priviliges */

1665

raise_privileges();

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

}

1666

2142

1667

2143

#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");

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

}

1675

2155

}

1676

2156

#endif /* __linux__ */

1677

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

1678

ret_errno = errno;

2157

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

2158

ioctl_errno = errno;

1679

2159

#ifdef __linux__

1680

2160

if(restore_loglevel){

1681

2161

ret_linux = klogctl(7, NULL, 0);

1685

2165

}

1686

2166

#endif /* __linux__ */

1687

2167

1688

/* Lower privileges */

1689

lower_privileges();

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

}

1690

2177

1691

2178

/* Close the socket */

1692

2179

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

1695

2182

}

1696

2183

1697

2184

if(ret_setflags == -1){

1698

errno = ret_errno;

2185

errno = ioctl_errno;

1699

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1700

2187

errno = old_errno;

1701

return ret_errno;

2188

return ioctl_errno;

1702

2189

}

1703

2190

} else if(debug){

1704

2191

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

1722

2209

return 0;

1723

2210

}

1724

2211

2212

__attribute__((nonnull, warn_unused_result))

1725

2213

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

1727

2214

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

1730

2215

struct ifreq network;

1731

2216

unsigned int if_index = if_nametoindex(interface);

1732

2217

if(if_index == 0){

1735

2220

return ENXIO;

1736

2221

}

1737

2222

if(interface_is_up(interface)){

2223

error_t ret_errno = 0, ioctl_errno = 0;

1738

2224

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

1739

2225

ret_errno = errno;

1740

2226

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

1741

2227

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

2228

errno = old_errno;

1742

2229

return ret_errno;

1743

2230

}

1744

2231

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

1745

2232

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2233

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

2234

if(sd == -1){

1748

2235

ret_errno = errno;

1749

2236

perror_plus("socket");

1750

2237

errno = old_errno;

1756

2243

interface);

1757

2244

}

1758

2245

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();

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

}

2252

2253

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

2254

ioctl_errno = errno;

2255

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

}

1767

2265

1768

2266

/* Close the socket */

1769

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

2267

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

1770

2268

if(ret == -1){

1771

2269

perror_plus("close");

1772

2270

}

1773

2271

1774

2272

if(ret_setflags == -1){

1775

errno = ret_errno;

2273

errno = ioctl_errno;

1776

2274

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1777

2275

errno = old_errno;

1778

return ret_errno;

2276

return ioctl_errno;

1779

2277

}

1780

2278

} else if(debug){

1781

2279

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

1787

2285

}

1788

2286

1789

2287

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

1790

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

2288

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

1791

2289

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

1792

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

2290

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

1793

2291

.interfaces = NULL, .interfaces_size = 0 };

1794

2292

AvahiSServiceBrowser *sb = NULL;

1795

2293

error_t ret_errno;

1799

2297

int exitcode = EXIT_SUCCESS;

1800

2298

char *interfaces_to_take_down = NULL;

1801

2299

size_t interfaces_to_take_down_size = 0;

1802

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

1803

bool tempdir_created = false;

2300

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

2301

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

2302

char *tempdir = NULL;

1804

2303

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1805

2304

const char *seckey = PATHDIR "/" SECKEY;

1806

2305

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

1807

2307

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

1809

2308

1810

2309

bool gnutls_initialized = false;

1811

2310

bool gpgme_initialized = false;

1863

2362

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

1864

2363

" Diffie-Hellman key exchange",

1865

2364

.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 },

1866

2370

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

1867

2371

.arg = "STRING",

1868

2372

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

1923

2427

}

1924

2428

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

1925

2429

break;

2430

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

2431

dh_params_file = arg;

2432

break;

1926

2433

case 130: /* --priority */

1927

2434

mc.priority = arg;

1928

2435

break;

1984

2491

goto end;

1985

2492

}

1986

2493

}

1987

2494

1988

2495

{

1989

2496

/* Work around Debian bug #633582:

1990

2497

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

1991

2498

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

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 {

1994

2505

struct stat st;

1995

2506

1996

2507

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

2013

2524

TEMP_FAILURE_RETRY(close(seckey_fd));

2014

2525

}

2015

2526

}

2016

2527

2017

2528

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

2018

2529

int pubkey_fd = open(pubkey, O_RDONLY);

2019

2530

if(pubkey_fd == -1){

2034

2545

TEMP_FAILURE_RETRY(close(pubkey_fd));

2035

2546

}

2036

2547

}

2037

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

2038

2570

/* Lower privileges */

2039

lower_privileges();

2571

ret_errno = lower_privileges();

2572

if(ret_errno != 0){

2573

errno = ret_errno;

2574

perror_plus("Failed to lower privileges");

2575

}

2040

2576

}

2041

2577

}

2042

2578

2066

2602

goto end;

2067

2603

}

2068

2604

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

}

2605

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

2606

}

2607

run_network_hooks("start", interfaces_hooks != NULL ?

2608

interfaces_hooks : "", delay);

2077

2609

}

2078

2610

2079

2611

if(not debug){

2157

2689

2158

2690

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

2159

2691

if(mc.interfaces == NULL){

2160

struct dirent **direntries;

2692

struct dirent **direntries = NULL;

2161

2693

/* Look for any good interfaces */

2162

2694

ret = scandir(sys_class_net, &direntries, good_interface,

2163

2695

alphasort);

2167

2699

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

2168

2700

direntries[i]->d_name);

2169

2701

if(ret_errno != 0){

2702

errno = ret_errno;

2170

2703

perror_plus("argz_add");

2704

free(direntries[i]);

2171

2705

continue;

2172

2706

}

2173

2707

if(debug){

2174

2708

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

2175

2709

direntries[i]->d_name);

2176

2710

}

2711

free(direntries[i]);

2177

2712

}

2178

2713

free(direntries);

2179

2714

} else {

2180

free(direntries);

2715

if(ret == 0){

2716

free(direntries);

2717

}

2181

2718

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

2182

2719

exitcode = EXIT_FAILURE;

2183

2720

goto end;

2206

2743

break;

2207

2744

}

2208

2745

bool interface_was_up = interface_is_up(interface);

2209

ret = bring_up_interface(interface, delay);

2746

errno = bring_up_interface(interface, delay);

2210

2747

if(not interface_was_up){

2211

if(ret != 0){

2212

errno = ret;

2213

perror_plus("Failed to bring up interface");

2748

if(errno != 0){

2749

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

2750

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

2214

2751

} else {

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2752

errno = argz_add(&interfaces_to_take_down,

2753

&interfaces_to_take_down_size,

2754

interface);

2755

if(errno != 0){

2756

perror_plus("argz_add");

2757

}

2218

2758

}

2219

2759

}

2220

2760

}

2236

2776

goto end;

2237

2777

}

2238

2778

2239

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

2779

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

2240

2780

if(ret == -1){

2241

2781

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

2242

2782

exitcode = EX_UNAVAILABLE;

2249

2789

goto end;

2250

2790

}

2251

2791

2252

if(mkdtemp(tempdir) == NULL){

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){

2253

2802

perror_plus("mkdtemp");

2254

2803

goto end;

2255

2804

}

2256

tempdir_created = true;

2257

2805

2258

2806

if(quit_now){

2259

2807

goto end;

2334

2882

sleep((unsigned int)retry_interval);

2335

2883

}

2336

2884

2337

if (not quit_now){

2885

if(not quit_now){

2338

2886

exitcode = EXIT_SUCCESS;

2339

2887

}

2340

2888

2395

2943

if(debug){

2396

2944

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

2397

2945

}

2398

2946

2399

2947

ret = avahi_loop_with_timeout(simple_poll,

2400

2948

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

2401

2949

if(debug){

2437

2985

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

2438

2986

while(mc.current_server != NULL){

2439

2987

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

2440

2996

free(mc.current_server);

2441

2997

mc.current_server = next;

2442

2998

}

2443

2999

}

2444

3000

2445

/* Re-raise priviliges */

3001

/* Re-raise privileges */

2446

3002

{

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();

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

}

2472

3037

}

2473

3038

2474

3039

free(interfaces_to_take_down);

2475

3040

free(interfaces_hooks);

2476

3041

2477

3042

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

2478

if(tempdir_created){

3043

if(tempdir != NULL){

2479

3044

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);

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

}

2499

3084

}

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");

3085

TEMP_FAILURE_RETRY(close(tempdir_fd));

2510

3086

}

2511

3087

}

2512

3088