/mandos/trunk : revision 524

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

26

* along with this program. If not, see

27

* <http://www.gnu.org/licenses/>.

28

*

29

* Contact the authors at <mandos@fukt.bsnet.se>.

29

* Contact the authors at <mandos@recompile.se>.

30

*/

31

32

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

33

#ifndef _LARGEFILE_SOURCE

33

34

#define _LARGEFILE_SOURCE

35

#endif

36

#ifndef _FILE_OFFSET_BITS

34

37

#define _FILE_OFFSET_BITS 64

38

#endif

35

39

36

40

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

37

41

38

42

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

39

stdout, ferror(), sscanf(),

40

remove() */

43

stdout, ferror(), remove() */

41

44

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

42

45

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

43

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

44

srand() */

46

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

47

strtof(), abort() */

45

48

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

46

49

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

47

50

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

56

59

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

57

60

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

58

61

*/

59

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

62

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

63

strtoimax() */

60

64

#include <assert.h> /* assert() */

61

#include <errno.h> /* perror(), errno */

62

#include <time.h> /* nanosleep(), time() */

65

#include <errno.h> /* perror(), errno,

66

program_invocation_short_name */

67

#include <time.h> /* nanosleep(), time(), sleep() */

63

68

#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

64

69

SIOCSIFFLAGS, if_indextoname(),

65

70

if_nametoindex(), IF_NAMESIZE */

67

72

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

68

73

*/

69

74

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

70

getuid(), getgid(), setuid(),

71

setgid() */

72

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

75

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

76

setgid(), pause() */

77

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

73

78

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

74

79

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

75

80

argp_state, struct argp,

76

81

argp_parse(), ARGP_KEY_ARG,

77

82

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

78

#include <signal.h> /* sigemptyset(), sigaddset(), sigaction(), SIGTERM, sigaction */

83

#include <signal.h> /* sigemptyset(), sigaddset(),

84

sigaction(), SIGTERM, sig_atomic_t,

85

raise() */

86

#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,

87

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

88

79

89

#ifdef __linux__

80

90

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

81

#endif

91

#endif /* __linux__ */

82

92

83

93

/* Avahi */

84

94

/* All Avahi types, constants and functions

117

127

bool debug = false;

118

128

static const char mandos_protocol_version[] = "1";

119

129

const char *argp_program_version = "mandos-client " VERSION;

120

const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";

130

const char *argp_program_bug_address = "<mandos@recompile.se>";

131

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

132

char *connect_to = NULL;

133

134

/* Doubly linked list that need to be circularly linked when used */

135

typedef struct server{

136

const char *ip;

137

uint16_t port;

138

AvahiIfIndex if_index;

139

int af;

140

struct timespec last_seen;

141

struct server *next;

142

struct server *prev;

143

} server;

121

144

122

145

/* Used for passing in values through the Avahi callback functions */

123

146

typedef struct {

128

151

gnutls_dh_params_t dh_params;

129

152

const char *priority;

130

153

gpgme_ctx_t ctx;

154

server *current_server;

131

155

} mandos_context;

132

156

133

157

/* global context so signal handler can reach it*/

134

mandos_context mc;

158

mandos_context mc = { .simple_poll = NULL, .server = NULL,

159

.dh_bits = 1024, .priority = "SECURE256"

160

":!CTYPE-X.509:+CTYPE-OPENPGP",

161

.current_server = NULL };

162

163

sig_atomic_t quit_now = 0;

164

int signal_received = 0;

165

166

/* Function to use when printing errors */

167

void perror_plus(const char *print_text){

168

fprintf(stderr, "Mandos plugin %s: ",

169

program_invocation_short_name);

170

perror(print_text);

171

}

135

172

136

173

/*

137

* Make additional room in "buffer" for at least BUFFER_SIZE

138

* additional bytes. "buffer_capacity" is how much is currently

139

* allocated, "buffer_length" is how much is already used.

174

* Make additional room in "buffer" for at least BUFFER_SIZE more

175

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

176

* "buffer_length" is how much is already used.

140

177

*/

141

178

size_t incbuffer(char **buffer, size_t buffer_length,

142

179

size_t buffer_capacity){

150

187

return buffer_capacity;

151

188

}

152

189

190

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

191

int add_server(const char *ip, uint16_t port,

192

AvahiIfIndex if_index,

193

int af){

194

int ret;

195

server *new_server = malloc(sizeof(server));

196

if(new_server == NULL){

197

perror_plus("malloc");

198

return -1;

199

}

200

*new_server = (server){ .ip = strdup(ip),

201

.port = port,

202

.if_index = if_index,

203

.af = af };

204

if(new_server->ip == NULL){

205

perror_plus("strdup");

206

return -1;

207

}

208

/* Special case of first server */

209

if (mc.current_server == NULL){

210

new_server->next = new_server;

211

new_server->prev = new_server;

212

mc.current_server = new_server;

213

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

214

} else {

215

new_server->next = mc.current_server;

216

new_server->prev = mc.current_server->prev;

217

new_server->prev->next = new_server;

218

mc.current_server->prev = new_server;

219

}

220

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

221

if(ret == -1){

222

perror_plus("clock_gettime");

223

return -1;

224

}

225

return 0;

226

}

227

153

228

/*

154

229

* Initialize GPGME.

155

230

*/

156

231

static bool init_gpgme(const char *seckey,

157

232

const char *pubkey, const char *tempdir){

158

int ret;

159

233

gpgme_error_t rc;

160

234

gpgme_engine_info_t engine_info;

161

235

164

238

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

165

239

*/

166

240

bool import_key(const char *filename){

241

int ret;

167

242

int fd;

168

243

gpgme_data_t pgp_data;

169

244

170

245

fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));

171

246

if(fd == -1){

172

perror("open");

247

perror_plus("open");

173

248

return false;

174

249

}

175

250

189

264

190

265

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

191

266

if(ret == -1){

192

perror("close");

267

perror_plus("close");

193

268

}

194

269

gpgme_data_release(pgp_data);

195

270

return true;

196

271

}

197

272

198

273

if(debug){

199

fprintf(stderr, "Initialize gpgme\n");

274

fprintf(stderr, "Initializing GPGME\n");

200

275

}

201

276

202

277

/* Init GPGME */

208

283

return false;

209

284

}

210

285

211

/* Set GPGME home directory for the OpenPGP engine only */

286

/* Set GPGME home directory for the OpenPGP engine only */

212

287

rc = gpgme_get_engine_info(&engine_info);

213

288

if(rc != GPG_ERR_NO_ERROR){

214

289

fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",

240

315

return false;

241

316

}

242

317

243

return true;

318

return true;

244

319

}

245

320

246

321

/*

300

375

}

301

376

gpgme_recipient_t recipient;

302

377

recipient = result->recipients;

303

if(recipient){

304

while(recipient != NULL){

305

fprintf(stderr, "Public key algorithm: %s\n",

306

gpgme_pubkey_algo_name(recipient->pubkey_algo));

307

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

308

fprintf(stderr, "Secret key available: %s\n",

309

recipient->status == GPG_ERR_NO_SECKEY

310

? "No" : "Yes");

311

recipient = recipient->next;

312

}

378

while(recipient != NULL){

379

fprintf(stderr, "Public key algorithm: %s\n",

380

gpgme_pubkey_algo_name(recipient->pubkey_algo));

381

fprintf(stderr, "Key ID: %s\n", recipient->keyid);

382

fprintf(stderr, "Secret key available: %s\n",

383

recipient->status == GPG_ERR_NO_SECKEY

384

? "No" : "Yes");

385

recipient = recipient->next;

313

386

}

314

387

}

315

388

}

322

395

323

396

/* Seek back to the beginning of the GPGME plaintext data buffer */

324

397

if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){

325

perror("gpgme_data_seek");

398

perror_plus("gpgme_data_seek");

326

399

plaintext_length = -1;

327

400

goto decrypt_end;

328

401

}

333

406

(size_t)plaintext_length,

334

407

plaintext_capacity);

335

408

if(plaintext_capacity == 0){

336

perror("incbuffer");

409

perror_plus("incbuffer");

337

410

plaintext_length = -1;

338

411

goto decrypt_end;

339

412

}

346

419

break;

347

420

}

348

421

if(ret < 0){

349

perror("gpgme_data_read");

422

perror_plus("gpgme_data_read");

350

423

plaintext_length = -1;

351

424

goto decrypt_end;

352

425

}

409

482

}

410

483

411

484

/* OpenPGP credentials */

412

gnutls_certificate_allocate_credentials(&mc.cred);

485

ret = gnutls_certificate_allocate_credentials(&mc.cred);

413

486

if(ret != GNUTLS_E_SUCCESS){

414

fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning

415

from

416

-Wunreachable-code

417

*/

487

fprintf(stderr, "GnuTLS memory error: %s\n",

418

488

safer_gnutls_strerror(ret));

419

489

gnutls_global_deinit();

420

490

return -1;

467

537

static int init_gnutls_session(gnutls_session_t *session){

468

538

int ret;

469

539

/* GnuTLS session creation */

470

ret = gnutls_init(session, GNUTLS_SERVER);

540

do {

541

ret = gnutls_init(session, GNUTLS_SERVER);

542

if(quit_now){

543

return -1;

544

}

545

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

471

546

if(ret != GNUTLS_E_SUCCESS){

472

547

fprintf(stderr, "Error in GnuTLS session initialization: %s\n",

473

548

safer_gnutls_strerror(ret));

475

550

476

551

{

477

552

const char *err;

478

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

553

do {

554

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

555

if(quit_now){

556

gnutls_deinit(*session);

557

return -1;

558

}

559

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

479

560

if(ret != GNUTLS_E_SUCCESS){

480

561

fprintf(stderr, "Syntax error at: %s\n", err);

481

562

fprintf(stderr, "GnuTLS error: %s\n",

485

566

}

486

567

}

487

568

488

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

489

mc.cred);

569

do {

570

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

571

mc.cred);

572

if(quit_now){

573

gnutls_deinit(*session);

574

return -1;

575

}

576

} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);

490

577

if(ret != GNUTLS_E_SUCCESS){

491

578

fprintf(stderr, "Error setting GnuTLS credentials: %s\n",

492

579

safer_gnutls_strerror(ret));

495

582

}

496

583

497

584

/* ignore client certificate if any. */

498

gnutls_certificate_server_set_request(*session,

499

GNUTLS_CERT_IGNORE);

585

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

500

586

501

587

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

502

588

511

597

static int start_mandos_communication(const char *ip, uint16_t port,

512

598

AvahiIfIndex if_index,

513

599

int af){

514

int ret, tcp_sd;

600

int ret, tcp_sd = -1;

515

601

ssize_t sret;

516

602

union {

517

603

struct sockaddr_in in;

518

604

struct sockaddr_in6 in6;

519

605

} to;

520

606

char *buffer = NULL;

521

char *decrypted_buffer;

607

char *decrypted_buffer = NULL;

522

608

size_t buffer_length = 0;

523

609

size_t buffer_capacity = 0;

524

ssize_t decrypted_buffer_size;

525

610

size_t written;

526

int retval = 0;

611

int retval = -1;

527

612

gnutls_session_t session;

528

613

int pf; /* Protocol family */

529

614

615

errno = 0;

616

617

if(quit_now){

618

errno = EINTR;

619

return -1;

620

}

621

530

622

switch(af){

531

623

case AF_INET6:

532

624

pf = PF_INET6;

536

628

break;

537

629

default:

538

630

fprintf(stderr, "Bad address family: %d\n", af);

631

errno = EINVAL;

539

632

return -1;

540

633

}

541

634

551

644

552

645

tcp_sd = socket(pf, SOCK_STREAM, 0);

553

646

if(tcp_sd < 0){

554

perror("socket");

555

return -1;

647

int e = errno;

648

perror_plus("socket");

649

errno = e;

650

goto mandos_end;

651

}

652

653

if(quit_now){

654

errno = EINTR;

655

goto mandos_end;

556

656

}

557

657

558

658

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

559

659

if(af == AF_INET6){

560

to.in6.sin6_family = (uint16_t)af;

660

to.in6.sin6_family = (sa_family_t)af;

561

661

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

562

662

} else { /* IPv4 */

563

663

to.in.sin_family = (sa_family_t)af;

564

664

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

565

665

}

566

666

if(ret < 0 ){

567

perror("inet_pton");

568

return -1;

667

int e = errno;

668

perror_plus("inet_pton");

669

errno = e;

670

goto mandos_end;

569

671

}

570

672

if(ret == 0){

673

int e = errno;

571

674

fprintf(stderr, "Bad address: %s\n", ip);

572

return -1;

675

errno = e;

676

goto mandos_end;

573

677

}

574

678

if(af == AF_INET6){

575

679

to.in6.sin6_port = htons(port); /* Spurious warnings from

582

686

if(if_index == AVAHI_IF_UNSPEC){

583

687

fprintf(stderr, "An IPv6 link-local address is incomplete"

584

688

" without a network interface\n");

585

return -1;

689

errno = EINVAL;

690

goto mandos_end;

586

691

}

587

692

/* Set the network interface number as scope */

588

693

to.in6.sin6_scope_id = (uint32_t)if_index;

593

698

-Wunreachable-code */

594

699

}

595

700

701

if(quit_now){

702

errno = EINTR;

703

goto mandos_end;

704

}

705

596

706

if(debug){

597

707

if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){

598

708

char interface[IF_NAMESIZE];

599

709

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

600

perror("if_indextoname");

710

perror_plus("if_indextoname");

601

711

} else {

602

712

fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",

603

713

ip, interface, port);

617

727

sizeof(addrstr));

618

728

}

619

729

if(pcret == NULL){

620

perror("inet_ntop");

730

perror_plus("inet_ntop");

621

731

} else {

622

732

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

623

733

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

625

735

}

626

736

}

627

737

738

if(quit_now){

739

errno = EINTR;

740

goto mandos_end;

741

}

742

628

743

if(af == AF_INET6){

629

744

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

630

745

} else {

631

746

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

632

747

}

633

748

if(ret < 0){

634

perror("connect");

635

return -1;

749

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

750

int e = errno;

751

perror_plus("connect");

752

errno = e;

753

}

754

goto mandos_end;

755

}

756

757

if(quit_now){

758

errno = EINTR;

759

goto mandos_end;

636

760

}

637

761

638

762

const char *out = mandos_protocol_version;

642

766

ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,

643

767

out_size - written));

644

768

if(ret == -1){

645

perror("write");

646

retval = -1;

769

int e = errno;

770

perror_plus("write");

771

errno = e;

647

772

goto mandos_end;

648

773

}

649

774

written += (size_t)ret;

657

782

break;

658

783

}

659

784

}

785

786

if(quit_now){

787

errno = EINTR;

788

goto mandos_end;

789

}

660

790

}

661

791

662

792

if(debug){

663

793

fprintf(stderr, "Establishing TLS session with %s\n", ip);

664

794

}

665

795

796

if(quit_now){

797

errno = EINTR;

798

goto mandos_end;

799

}

800

801

/* Spurious warning from -Wint-to-pointer-cast */

666

802

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

667

803

668

do{

804

if(quit_now){

805

errno = EINTR;

806

goto mandos_end;

807

}

808

809

do {

669

810

ret = gnutls_handshake(session);

811

if(quit_now){

812

errno = EINTR;

813

goto mandos_end;

814

}

670

815

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

671

816

672

817

if(ret != GNUTLS_E_SUCCESS){

674

819

fprintf(stderr, "*** GnuTLS Handshake failed ***\n");

675

820

gnutls_perror(ret);

676

821

}

677

retval = -1;

822

errno = EPROTO;

678

823

goto mandos_end;

679

824

}

680

825

686

831

}

687

832

688

833

while(true){

834

835

if(quit_now){

836

errno = EINTR;

837

goto mandos_end;

838

}

839

689

840

buffer_capacity = incbuffer(&buffer, buffer_length,

690

841

buffer_capacity);

691

842

if(buffer_capacity == 0){

692

perror("incbuffer");

693

retval = -1;

843

int e = errno;

844

perror_plus("incbuffer");

845

errno = e;

846

goto mandos_end;

847

}

848

849

if(quit_now){

850

errno = EINTR;

694

851

goto mandos_end;

695

852

}

696

853

705

862

case GNUTLS_E_AGAIN:

706

863

break;

707

864

case GNUTLS_E_REHANDSHAKE:

708

do{

865

do {

709

866

ret = gnutls_handshake(session);

867

868

if(quit_now){

869

errno = EINTR;

870

goto mandos_end;

871

}

710

872

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

711

873

if(ret < 0){

712

874

fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");

713

875

gnutls_perror(ret);

714

retval = -1;

876

errno = EPROTO;

715

877

goto mandos_end;

716

878

}

717

879

break;

718

880

default:

719

881

fprintf(stderr, "Unknown error while reading data from"

720

882

" encrypted session with Mandos server\n");

721

retval = -1;

722

883

gnutls_bye(session, GNUTLS_SHUT_RDWR);

884

errno = EIO;

723

885

goto mandos_end;

724

886

}

725

887

} else {

731

893

fprintf(stderr, "Closing TLS session\n");

732

894

}

733

895

734

gnutls_bye(session, GNUTLS_SHUT_RDWR);

896

if(quit_now){

897

errno = EINTR;

898

goto mandos_end;

899

}

900

901

do {

902

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

903

if(quit_now){

904

errno = EINTR;

905

goto mandos_end;

906

}

907

} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);

735

908

736

909

if(buffer_length > 0){

910

ssize_t decrypted_buffer_size;

737

911

decrypted_buffer_size = pgp_packet_decrypt(buffer,

738

912

buffer_length,

739

913

&decrypted_buffer);

740

914

if(decrypted_buffer_size >= 0){

915

741

916

written = 0;

742

917

while(written < (size_t) decrypted_buffer_size){

918

if(quit_now){

919

errno = EINTR;

920

goto mandos_end;

921

}

922

743

923

ret = (int)fwrite(decrypted_buffer + written, 1,

744

924

(size_t)decrypted_buffer_size - written,

745

925

stdout);

746

926

if(ret == 0 and ferror(stdout)){

927

int e = errno;

747

928

if(debug){

748

929

fprintf(stderr, "Error writing encrypted data: %s\n",

749

930

strerror(errno));

750

931

}

751

retval = -1;

752

break;

932

errno = e;

933

goto mandos_end;

753

934

}

754

935

written += (size_t)ret;

755

936

}

756

free(decrypted_buffer);

757

} else {

758

retval = -1;

937

retval = 0;

759

938

}

760

} else {

761

retval = -1;

762

939

}

763

940

764

941

/* Shutdown procedure */

765

942

766

943

mandos_end:

767

free(buffer);

768

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

769

if(ret == -1){

770

perror("close");

944

{

945

int e = errno;

946

free(decrypted_buffer);

947

free(buffer);

948

if(tcp_sd >= 0){

949

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

950

}

951

if(ret == -1){

952

if(e == 0){

953

e = errno;

954

}

955

perror_plus("close");

956

}

957

gnutls_deinit(session);

958

errno = e;

959

if(quit_now){

960

errno = EINTR;

961

retval = -1;

962

}

771

963

}

772

gnutls_deinit(session);

773

964

return retval;

774

965

}

775

966

786

977

AVAHI_GCC_UNUSED AvahiStringList *txt,

787

978

AVAHI_GCC_UNUSED AvahiLookupResultFlags

788

979

flags,

789

__attribute__((unused)) void* userdata){

980

AVAHI_GCC_UNUSED void* userdata){

790

981

assert(r);

791

982

792

983

/* Called whenever a service has been resolved successfully or

793

984

timed out */

794

985

986

if(quit_now){

987

return;

988

}

989

795

990

switch(event){

796

991

default:

797

992

case AVAHI_RESOLVER_FAILURE:

813

1008

avahi_proto_to_af(proto));

814

1009

if(ret == 0){

815

1010

avahi_simple_poll_quit(mc.simple_poll);

1011

} else {

1012

ret = add_server(ip, port, interface,

1013

avahi_proto_to_af(proto));

816

1014

}

817

1015

}

818

1016

}

828

1026

const char *domain,

829

1027

AVAHI_GCC_UNUSED AvahiLookupResultFlags

830

1028

flags,

831

__attribute__((unused)) void* userdata){

1029

AVAHI_GCC_UNUSED void* userdata){

832

1030

assert(b);

833

1031

834

1032

/* Called whenever a new services becomes available on the LAN or

835

1033

is removed from the LAN */

836

1034

1035

if(quit_now){

1036

return;

1037

}

1038

837

1039

switch(event){

838

1040

default:

839

1041

case AVAHI_BROWSER_FAILURE:

849

1051

the callback function is called the Avahi server will free the

850

1052

resolver for us. */

851

1053

852

if(!(avahi_s_service_resolver_new(mc.server, interface,

853

protocol, name, type, domain,

854

AVAHI_PROTO_INET6, 0,

855

resolve_callback, NULL)))

1054

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1055

name, type, domain, protocol, 0,

1056

resolve_callback, NULL) == NULL)

856

1057

fprintf(stderr, "Avahi: Failed to resolve service '%s': %s\n",

857

1058

name, avahi_strerror(avahi_server_errno(mc.server)));

858

1059

break;

869

1070

}

870

1071

}

871

1072

872

static void handle_sigterm(__attribute__((unused)) int sig){

1073

/* Signal handler that stops main loop after SIGTERM */

1074

static void handle_sigterm(int sig){

1075

if(quit_now){

1076

return;

1077

}

1078

quit_now = 1;

1079

signal_received = sig;

873

1080

int old_errno = errno;

874

avahi_simple_poll_quit(mc.simple_poll);

1081

/* set main loop to exit */

1082

if(mc.simple_poll != NULL){

1083

avahi_simple_poll_quit(mc.simple_poll);

1084

}

875

1085

errno = old_errno;

876

1086

}

877

1087

1088

/*

1089

* This function determines if a directory entry in /sys/class/net

1090

* corresponds to an acceptable network device.

1091

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

1092

*/

1093

int good_interface(const struct dirent *if_entry){

1094

ssize_t ssret;

1095

char *flagname = NULL;

1096

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

1097

return 0;

1098

}

1099

int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,

1100

if_entry->d_name);

1101

if(ret < 0){

1102

perror_plus("asprintf");

1103

return 0;

1104

}

1105

int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));

1106

if(flags_fd == -1){

1107

perror_plus("open");

1108

free(flagname);

1109

return 0;

1110

}

1111

free(flagname);

1112

typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */

1113

/* read line from flags_fd */

1114

ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */

1115

char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */

1116

flagstring[(size_t)to_read] = '\0';

1117

if(flagstring == NULL){

1118

perror_plus("malloc");

1119

close(flags_fd);

1120

return 0;

1121

}

1122

while(to_read > 0){

1123

ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,

1124

(size_t)to_read));

1125

if(ssret == -1){

1126

perror_plus("read");

1127

free(flagstring);

1128

close(flags_fd);

1129

return 0;

1130

}

1131

to_read -= ssret;

1132

if(ssret == 0){

1133

break;

1134

}

1135

}

1136

close(flags_fd);

1137

intmax_t tmpmax;

1138

char *tmp;

1139

errno = 0;

1140

tmpmax = strtoimax(flagstring, &tmp, 0);

1141

if(errno != 0 or tmp == flagstring or (*tmp != '\0'

1142

and not (isspace(*tmp)))

1143

or tmpmax != (ifreq_flags)tmpmax){

1144

if(debug){

1145

fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",

1146

flagstring, if_entry->d_name);

1147

}

1148

free(flagstring);

1149

return 0;

1150

}

1151

free(flagstring);

1152

ifreq_flags flags = (ifreq_flags)tmpmax;

1153

/* Reject the loopback device */

1154

if(flags & IFF_LOOPBACK){

1155

if(debug){

1156

fprintf(stderr, "Rejecting loopback interface \"%s\"\n",

1157

if_entry->d_name);

1158

}

1159

return 0;

1160

}

1161

/* Accept point-to-point devices only if connect_to is specified */

1162

if(connect_to != NULL and (flags & IFF_POINTOPOINT)){

1163

if(debug){

1164

fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",

1165

if_entry->d_name);

1166

}

1167

return 1;

1168

}

1169

/* Otherwise, reject non-broadcast-capable devices */

1170

if(not (flags & IFF_BROADCAST)){

1171

if(debug){

1172

fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",

1173

if_entry->d_name);

1174

}

1175

return 0;

1176

}

1177

/* Reject non-ARP interfaces (including dummy interfaces) */

1178

if(flags & IFF_NOARP){

1179

if(debug){

1180

fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",

1181

if_entry->d_name);

1182

}

1183

return 0;

1184

}

1185

/* Accept this device */

1186

if(debug){

1187

fprintf(stderr, "Interface \"%s\" is acceptable\n",

1188

if_entry->d_name);

1189

}

1190

return 1;

1191

}

1192

1193

int notdotentries(const struct dirent *direntry){

1194

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

1195

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

1196

and (direntry->d_name[1] == '\0'

1197

or (direntry->d_name[1] == '.'

1198

and direntry->d_name[2] == '\0'))){

1199

return 0;

1200

}

1201

return 1;

1202

}

1203

1204

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1205

int ret;

1206

struct timespec now;

1207

struct timespec waited_time;

1208

intmax_t block_time;

1209

1210

while(true){

1211

if(mc.current_server == NULL){

1212

if (debug){

1213

fprintf(stderr,

1214

"Wait until first server is found. No timeout!\n");

1215

}

1216

ret = avahi_simple_poll_iterate(s, -1);

1217

} else {

1218

if (debug){

1219

fprintf(stderr, "Check current_server if we should run it,"

1220

" or wait\n");

1221

}

1222

/* the current time */

1223

ret = clock_gettime(CLOCK_MONOTONIC, &now);

1224

if(ret == -1){

1225

perror_plus("clock_gettime");

1226

return -1;

1227

}

1228

/* Calculating in ms how long time between now and server

1229

who we visted longest time ago. Now - last seen. */

1230

waited_time.tv_sec = (now.tv_sec

1231

- mc.current_server->last_seen.tv_sec);

1232

waited_time.tv_nsec = (now.tv_nsec

1233

- mc.current_server->last_seen.tv_nsec);

1234

/* total time is 10s/10,000ms.

1235

Converting to s from ms by dividing by 1,000,

1236

and ns to ms by dividing by 1,000,000. */

1237

block_time = ((retry_interval

1238

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

1239

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

1240

1241

if (debug){

1242

fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);

1243

}

1244

1245

if(block_time <= 0){

1246

ret = start_mandos_communication(mc.current_server->ip,

1247

mc.current_server->port,

1248

mc.current_server->if_index,

1249

mc.current_server->af);

1250

if(ret == 0){

1251

avahi_simple_poll_quit(mc.simple_poll);

1252

return 0;

1253

}

1254

ret = clock_gettime(CLOCK_MONOTONIC,

1255

&mc.current_server->last_seen);

1256

if(ret == -1){

1257

perror_plus("clock_gettime");

1258

return -1;

1259

}

1260

mc.current_server = mc.current_server->next;

1261

block_time = 0; /* Call avahi to find new Mandos

1262

servers, but don't block */

1263

}

1264

1265

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

1266

}

1267

if(ret != 0){

1268

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

1269

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

1270

}

1271

}

1272

}

1273

}

1274

878

1275

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

879

1276

AvahiSServiceBrowser *sb = NULL;

880

1277

int error;

881

1278

int ret;

882

1279

intmax_t tmpmax;

883

int numchars;

1280

char *tmp;

884

1281

int exitcode = EXIT_SUCCESS;

885

const char *interface = "eth0";

1282

const char *interface = "";

886

1283

struct ifreq network;

887

int sd;

1284

int sd = -1;

1285

bool take_down_interface = false;

888

1286

uid_t uid;

889

1287

gid_t gid;

890

char *connect_to = NULL;

891

1288

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

892

1289

bool tempdir_created = false;

893

1290

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

896

1293

897

1294

bool gnutls_initialized = false;

898

1295

bool gpgme_initialized = false;

899

double delay = 2.5;

900

901

struct sigaction old_sigterm_action;

1296

float delay = 2.5f;

1297

double retry_interval = 10; /* 10s between trying a server and

1298

retrying the same server again */

1299

1300

struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };

902

1301

struct sigaction sigterm_action = { .sa_handler = handle_sigterm };

903

904

/* Initialize mandos context */

905

mc = (mandos_context){ .simple_poll = NULL, .server = NULL,

906

.dh_bits = 1024, .priority = "SECURE256"

907

":!CTYPE-X.509:+CTYPE-OPENPGP" };

1302

1303

uid = getuid();

1304

gid = getgid();

1305

1306

/* Lower any group privileges we might have, just to be safe */

1307

errno = 0;

1308

ret = setgid(gid);

1309

if(ret == -1){

1310

perror_plus("setgid");

1311

}

1312

1313

/* Lower user privileges (temporarily) */

1314

errno = 0;

1315

ret = seteuid(uid);

1316

if(ret == -1){

1317

perror_plus("seteuid");

1318

}

1319

1320

if(quit_now){

1321

goto end;

1322

}

908

1323

909

1324

{

910

1325

struct argp_option options[] = {

940

1355

.arg = "SECONDS",

941

1356

.doc = "Maximum delay to wait for interface startup",

942

1357

.group = 2 },

1358

{ .name = "retry", .key = 132,

1359

.arg = "SECONDS",

1360

.doc = "Retry interval used when denied by the mandos server",

1361

.group = 2 },

1362

/*

1363

* These reproduce what we would get without ARGP_NO_HELP

1364

*/

1365

{ .name = "help", .key = '?',

1366

.doc = "Give this help list", .group = -1 },

1367

{ .name = "usage", .key = -3,

1368

.doc = "Give a short usage message", .group = -1 },

1369

{ .name = "version", .key = 'V',

1370

.doc = "Print program version", .group = -1 },

943

1371

{ .name = NULL }

944

1372

};

945

1373

946

1374

error_t parse_opt(int key, char *arg,

947

1375

struct argp_state *state){

1376

errno = 0;

948

1377

switch(key){

949

1378

case 128: /* --debug */

950

1379

debug = true;

962

1391

pubkey = arg;

963

1392

break;

964

1393

case 129: /* --dh-bits */

965

ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);

966

if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax

967

or arg[numchars] != '\0'){

968

fprintf(stderr, "Bad number of DH bits\n");

969

exit(EXIT_FAILURE);

1394

errno = 0;

1395

tmpmax = strtoimax(arg, &tmp, 10);

1396

if(errno != 0 or tmp == arg or *tmp != '\0'

1397

or tmpmax != (typeof(mc.dh_bits))tmpmax){

1398

argp_error(state, "Bad number of DH bits");

970

1399

}

971

1400

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

972

1401

break;

974

1403

mc.priority = arg;

975

1404

break;

976

1405

case 131: /* --delay */

977

ret = sscanf(arg, "%lf%n", &delay, &numchars);

978

if(ret < 1 or arg[numchars] != '\0'){

979

fprintf(stderr, "Bad delay\n");

980

exit(EXIT_FAILURE);

1406

errno = 0;

1407

delay = strtof(arg, &tmp);

1408

if(errno != 0 or tmp == arg or *tmp != '\0'){

1409

argp_error(state, "Bad delay");

1410

}

1411

case 132: /* --retry */

1412

errno = 0;

1413

retry_interval = strtod(arg, &tmp);

1414

if(errno != 0 or tmp == arg or *tmp != '\0'

1415

or (retry_interval * 1000) > INT_MAX

1416

or retry_interval < 0){

1417

argp_error(state, "Bad retry interval");

981

1418

}

982

1419

break;

983

case ARGP_KEY_ARG:

984

argp_usage(state);

985

case ARGP_KEY_END:

1420

/*

1421

* These reproduce what we would get without ARGP_NO_HELP

1422

*/

1423

case '?': /* --help */

1424

argp_state_help(state, state->out_stream,

1425

(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)

1426

& ~(unsigned int)ARGP_HELP_EXIT_OK);

1427

case -3: /* --usage */

1428

argp_state_help(state, state->out_stream,

1429

ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);

1430

case 'V': /* --version */

1431

fprintf(state->out_stream, "%s\n", argp_program_version);

1432

exit(argp_err_exit_status);

986

1433

break;

987

1434

default:

988

1435

return ARGP_ERR_UNKNOWN;

989

1436

}

990

return 0;

1437

return errno;

991

1438

}

992

1439

993

1440

struct argp argp = { .options = options, .parser = parse_opt,

994

1441

.args_doc = "",

995

1442

.doc = "Mandos client -- Get and decrypt"

996

1443

" passwords from a Mandos server" };

997

ret = argp_parse(&argp, argc, argv, 0, 0, NULL);

998

if(ret == ARGP_ERR_UNKNOWN){

999

fprintf(stderr, "Unknown error while parsing arguments\n");

1444

ret = argp_parse(&argp, argc, argv,

1445

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1446

switch(ret){

1447

case 0:

1448

break;

1449

case ENOMEM:

1450

default:

1451

errno = ret;

1452

perror_plus("argp_parse");

1453

exitcode = EX_OSERR;

1454

goto end;

1455

case EINVAL:

1456

exitcode = EX_USAGE;

1457

goto end;

1458

}

1459

}

1460

1461

{

1462

/* Work around Debian bug #633582:

1463

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

1464

struct stat st;

1465

1466

/* Re-raise priviliges */

1467

errno = 0;

1468

ret = seteuid(0);

1469

if(ret == -1){

1470

perror_plus("seteuid");

1471

}

1472

1473

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

1474

int seckey_fd = open(seckey, O_RDONLY);

1475

if(seckey_fd == -1){

1476

perror_plus("open");

1477

} else {

1478

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

1479

if(ret == -1){

1480

perror_plus("fstat");

1481

} else {

1482

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1483

ret = fchown(seckey_fd, uid, gid);

1484

if(ret == -1){

1485

perror_plus("fchown");

1486

}

1487

}

1488

}

1489

TEMP_FAILURE_RETRY(close(seckey_fd));

1490

}

1491

}

1492

1493

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

1494

int pubkey_fd = open(pubkey, O_RDONLY);

1495

if(pubkey_fd == -1){

1496

perror_plus("open");

1497

} else {

1498

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

1499

if(ret == -1){

1500

perror_plus("fstat");

1501

} else {

1502

if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){

1503

ret = fchown(pubkey_fd, uid, gid);

1504

if(ret == -1){

1505

perror_plus("fchown");

1506

}

1507

}

1508

}

1509

TEMP_FAILURE_RETRY(close(pubkey_fd));

1510

}

1511

}

1512

1513

/* Lower privileges */

1514

errno = 0;

1515

ret = seteuid(uid);

1516

if(ret == -1){

1517

perror_plus("seteuid");

1518

}

1519

}

1520

1521

if(not debug){

1522

avahi_set_log_function(empty_log);

1523

}

1524

1525

if(interface[0] == '\0'){

1526

struct dirent **direntries;

1527

ret = scandir(sys_class_net, &direntries, good_interface,

1528

alphasort);

1529

if(ret >= 1){

1530

/* Pick the first good interface */

1531

interface = strdup(direntries[0]->d_name);

1532

if(debug){

1533

fprintf(stderr, "Using interface \"%s\"\n", interface);

1534

}

1535

if(interface == NULL){

1536

perror_plus("malloc");

1537

free(direntries);

1538

exitcode = EXIT_FAILURE;

1539

goto end;

1540

}

1541

free(direntries);

1542

} else {

1543

free(direntries);

1544

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

1000

1545

exitcode = EXIT_FAILURE;

1001

1546

goto end;

1002

1547

}

1003

1548

}

1004

1549

1550

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

1551

from the signal handler */

1552

/* Initialize the pseudo-RNG for Avahi */

1553

srand((unsigned int) time(NULL));

1554

mc.simple_poll = avahi_simple_poll_new();

1555

if(mc.simple_poll == NULL){

1556

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1557

exitcode = EX_UNAVAILABLE;

1558

goto end;

1559

}

1560

1561

sigemptyset(&sigterm_action.sa_mask);

1562

ret = sigaddset(&sigterm_action.sa_mask, SIGINT);

1563

if(ret == -1){

1564

perror_plus("sigaddset");

1565

exitcode = EX_OSERR;

1566

goto end;

1567

}

1568

ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);

1569

if(ret == -1){

1570

perror_plus("sigaddset");

1571

exitcode = EX_OSERR;

1572

goto end;

1573

}

1574

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1575

if(ret == -1){

1576

perror_plus("sigaddset");

1577

exitcode = EX_OSERR;

1578

goto end;

1579

}

1580

/* Need to check if the handler is SIG_IGN before handling:

1581

| [[info:libc:Initial Signal Actions]] |

1582

| [[info:libc:Basic Signal Handling]] |

1583

*/

1584

ret = sigaction(SIGINT, NULL, &old_sigterm_action);

1585

if(ret == -1){

1586

perror_plus("sigaction");

1587

return EX_OSERR;

1588

}

1589

if(old_sigterm_action.sa_handler != SIG_IGN){

1590

ret = sigaction(SIGINT, &sigterm_action, NULL);

1591

if(ret == -1){

1592

perror_plus("sigaction");

1593

exitcode = EX_OSERR;

1594

goto end;

1595

}

1596

}

1597

ret = sigaction(SIGHUP, NULL, &old_sigterm_action);

1598

if(ret == -1){

1599

perror_plus("sigaction");

1600

return EX_OSERR;

1601

}

1602

if(old_sigterm_action.sa_handler != SIG_IGN){

1603

ret = sigaction(SIGHUP, &sigterm_action, NULL);

1604

if(ret == -1){

1605

perror_plus("sigaction");

1606

exitcode = EX_OSERR;

1607

goto end;

1608

}

1609

}

1610

ret = sigaction(SIGTERM, NULL, &old_sigterm_action);

1611

if(ret == -1){

1612

perror_plus("sigaction");

1613

return EX_OSERR;

1614

}

1615

if(old_sigterm_action.sa_handler != SIG_IGN){

1616

ret = sigaction(SIGTERM, &sigterm_action, NULL);

1617

if(ret == -1){

1618

perror_plus("sigaction");

1619

exitcode = EX_OSERR;

1620

goto end;

1621

}

1622

}

1623

1005

1624

/* If the interface is down, bring it up */

1006

if(interface[0] != '\0'){

1625

if(strcmp(interface, "none") != 0){

1626

if_index = (AvahiIfIndex) if_nametoindex(interface);

1627

if(if_index == 0){

1628

fprintf(stderr, "No such interface: \"%s\"\n", interface);

1629

exitcode = EX_UNAVAILABLE;

1630

goto end;

1631

}

1632

1633

if(quit_now){

1634

goto end;

1635

}

1636

1637

/* Re-raise priviliges */

1638

errno = 0;

1639

ret = seteuid(0);

1640

if(ret == -1){

1641

perror_plus("seteuid");

1642

}

1643

1007

1644

#ifdef __linux__

1008

1645

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1009

messages to mess up the prompt */

1646

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

1010

1647

ret = klogctl(8, NULL, 5);

1011

1648

bool restore_loglevel = true;

1012

1649

if(ret == -1){

1013

1650

restore_loglevel = false;

1014

perror("klogctl");

1651

perror_plus("klogctl");

1015

1652

}

1016

#endif

1653

#endif /* __linux__ */

1017

1654

1018

1655

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1019

1656

if(sd < 0){

1020

perror("socket");

1021

exitcode = EXIT_FAILURE;

1657

perror_plus("socket");

1658

exitcode = EX_OSERR;

1022

1659

#ifdef __linux__

1023

1660

if(restore_loglevel){

1024

1661

ret = klogctl(7, NULL, 0);

1025

1662

if(ret == -1){

1026

perror("klogctl");

1663

perror_plus("klogctl");

1027

1664

}

1028

1665

}

1029

#endif

1666

#endif /* __linux__ */

1667

/* Lower privileges */

1668

errno = 0;

1669

ret = seteuid(uid);

1670

if(ret == -1){

1671

perror_plus("seteuid");

1672

}

1030

1673

goto end;

1031

1674

}

1032

1675

strcpy(network.ifr_name, interface);

1033

1676

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1034

1677

if(ret == -1){

1035

perror("ioctl SIOCGIFFLAGS");

1678

perror_plus("ioctl SIOCGIFFLAGS");

1036

1679

#ifdef __linux__

1037

1680

if(restore_loglevel){

1038

1681

ret = klogctl(7, NULL, 0);

1039

1682

if(ret == -1){

1040

perror("klogctl");

1683

perror_plus("klogctl");

1041

1684

}

1042

1685

}

1043

#endif

1044

exitcode = EXIT_FAILURE;

1686

#endif /* __linux__ */

1687

exitcode = EX_OSERR;

1688

/* Lower privileges */

1689

errno = 0;

1690

ret = seteuid(uid);

1691

if(ret == -1){

1692

perror_plus("seteuid");

1693

}

1045

1694

goto end;

1046

1695

}

1047

1696

if((network.ifr_flags & IFF_UP) == 0){

1048

1697

network.ifr_flags |= IFF_UP;

1698

take_down_interface = true;

1049

1699

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

1050

1700

if(ret == -1){

1051

perror("ioctl SIOCSIFFLAGS");

1052

exitcode = EXIT_FAILURE;

1701

take_down_interface = false;

1702

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1703

exitcode = EX_OSERR;

1053

1704

#ifdef __linux__

1054

1705

if(restore_loglevel){

1055

1706

ret = klogctl(7, NULL, 0);

1056

1707

if(ret == -1){

1057

perror("klogctl");

1708

perror_plus("klogctl");

1058

1709

}

1059

1710

}

1060

#endif

1711

#endif /* __linux__ */

1712

/* Lower privileges */

1713

errno = 0;

1714

ret = seteuid(uid);

1715

if(ret == -1){

1716

perror_plus("seteuid");

1717

}

1061

1718

goto end;

1062

1719

}

1063

1720

}

1064

/* sleep checking until interface is running */

1721

/* Sleep checking until interface is running.

1722

Check every 0.25s, up to total time of delay */

1065

1723

for(int i=0; i < delay * 4; i++){

1066

1724

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1067

1725

if(ret == -1){

1068

perror("ioctl SIOCGIFFLAGS");

1726

perror_plus("ioctl SIOCGIFFLAGS");

1069

1727

} else if(network.ifr_flags & IFF_RUNNING){

1070

1728

break;

1071

1729

}

1072

1730

struct timespec sleeptime = { .tv_nsec = 250000000 };

1073

1731

ret = nanosleep(&sleeptime, NULL);

1074

1732

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

1075

perror("nanosleep");

1733

perror_plus("nanosleep");

1076

1734

}

1077

1735

}

1078

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

1079

if(ret == -1){

1080

perror("close");

1736

if(not take_down_interface){

1737

/* We won't need the socket anymore */

1738

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

1739

if(ret == -1){

1740

perror_plus("close");

1741

}

1081

1742

}

1082

1743

#ifdef __linux__

1083

1744

if(restore_loglevel){

1084

1745

/* Restores kernel loglevel to default */

1085

1746

ret = klogctl(7, NULL, 0);

1086

1747

if(ret == -1){

1087

perror("klogctl");

1088

}

1089

}

1090

#endif

1091

}

1092

1093

uid = getuid();

1094

gid = getgid();

1095

1096

errno = 0;

1097

setgid(gid);

1098

if(ret == -1){

1099

perror("setgid");

1100

}

1101

1102

ret = setuid(uid);

1103

if(ret == -1){

1104

perror("setuid");

1748

perror_plus("klogctl");

1749

}

1750

}

1751

#endif /* __linux__ */

1752

/* Lower privileges */

1753

errno = 0;

1754

if(take_down_interface){

1755

/* Lower privileges */

1756

ret = seteuid(uid);

1757

if(ret == -1){

1758

perror_plus("seteuid");

1759

}

1760

} else {

1761

/* Lower privileges permanently */

1762

ret = setuid(uid);

1763

if(ret == -1){

1764

perror_plus("setuid");

1765

}

1766

}

1767

}

1768

1769

if(quit_now){

1770

goto end;

1105

1771

}

1106

1772

1107

1773

ret = init_gnutls_global(pubkey, seckey);

1108

1774

if(ret == -1){

1109

1775

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

1110

exitcode = EXIT_FAILURE;

1776

exitcode = EX_UNAVAILABLE;

1111

1777

goto end;

1112

1778

} else {

1113

1779

gnutls_initialized = true;

1114

1780

}

1115

1781

1782

if(quit_now){

1783

goto end;

1784

}

1785

1116

1786

if(mkdtemp(tempdir) == NULL){

1117

perror("mkdtemp");

1787

perror_plus("mkdtemp");

1118

1788

goto end;

1119

1789

}

1120

1790

tempdir_created = true;

1121

1791

1792

if(quit_now){

1793

goto end;

1794

}

1795

1122

1796

if(not init_gpgme(pubkey, seckey, tempdir)){

1123

1797

fprintf(stderr, "init_gpgme failed\n");

1124

exitcode = EXIT_FAILURE;

1798

exitcode = EX_UNAVAILABLE;

1125

1799

goto end;

1126

1800

} else {

1127

1801

gpgme_initialized = true;

1128

1802

}

1129

1803

1130

if(interface[0] != '\0'){

1131

if_index = (AvahiIfIndex) if_nametoindex(interface);

1132

if(if_index == 0){

1133

fprintf(stderr, "No such interface: \"%s\"\n", interface);

1134

exitcode = EXIT_FAILURE;

1135

goto end;

1136

}

1804

if(quit_now){

1805

goto end;

1137

1806

}

1138

1807

1139

1808

if(connect_to != NULL){

1142

1811

char *address = strrchr(connect_to, ':');

1143

1812

if(address == NULL){

1144

1813

fprintf(stderr, "No colon in address\n");

1145

exitcode = EXIT_FAILURE;

1146

goto end;

1147

}

1814

exitcode = EX_USAGE;

1815

goto end;

1816

}

1817

1818

if(quit_now){

1819

goto end;

1820

}

1821

1148

1822

uint16_t port;

1149

ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);

1150

if(ret < 1 or tmpmax != (uint16_t)tmpmax

1151

or address[numchars+1] != '\0'){

1823

errno = 0;

1824

tmpmax = strtoimax(address+1, &tmp, 10);

1825

if(errno != 0 or tmp == address+1 or *tmp != '\0'

1826

or tmpmax != (uint16_t)tmpmax){

1152

1827

fprintf(stderr, "Bad port number\n");

1153

exitcode = EXIT_FAILURE;

1154

goto end;

1155

}

1828

exitcode = EX_USAGE;

1829

goto end;

1830

}

1831

1832

if(quit_now){

1833

goto end;

1834

}

1835

1156

1836

port = (uint16_t)tmpmax;

1157

1837

*address = '\0';

1158

address = connect_to;

1159

1838

/* Colon in address indicates IPv6 */

1160

1839

int af;

1161

if(strchr(address, ':') != NULL){

1840

if(strchr(connect_to, ':') != NULL){

1162

1841

af = AF_INET6;

1842

/* Accept [] around IPv6 address - see RFC 5952 */

1843

if(connect_to[0] == '[' and address[-1] == ']')

1844

{

1845

connect_to++;

1846

address[-1] = '\0';

1847

}

1163

1848

} else {

1164

1849

af = AF_INET;

1165

1850

}

1166

ret = start_mandos_communication(address, port, if_index,

1167

af);

1168

if(ret < 0){

1169

exitcode = EXIT_FAILURE;

1170

} else {

1851

address = connect_to;

1852

1853

if(quit_now){

1854

goto end;

1855

}

1856

1857

while(not quit_now){

1858

ret = start_mandos_communication(address, port, if_index, af);

1859

if(quit_now or ret == 0){

1860

break;

1861

}

1862

if(debug){

1863

fprintf(stderr, "Retrying in %d seconds\n",

1864

(int)retry_interval);

1865

}

1866

sleep((int)retry_interval);

1867

}

1868

1869

if (not quit_now){

1171

1870

exitcode = EXIT_SUCCESS;

1172

1871

}

1872

1173

1873

goto end;

1174

1874

}

1175

1875

1176

if(not debug){

1177

avahi_set_log_function(empty_log);

1178

}

1179

1180

/* Initialize the pseudo-RNG for Avahi */

1181

srand((unsigned int) time(NULL));

1182

1183

/* Allocate main Avahi loop object */

1184

mc.simple_poll = avahi_simple_poll_new();

1185

if(mc.simple_poll == NULL){

1186

fprintf(stderr, "Avahi: Failed to create simple poll object.\n");

1187

exitcode = EXIT_FAILURE;

1876

if(quit_now){

1188

1877

goto end;

1189

1878

}

1190

1879

1210

1899

if(mc.server == NULL){

1211

1900

fprintf(stderr, "Failed to create Avahi server: %s\n",

1212

1901

avahi_strerror(error));

1213

exitcode = EXIT_FAILURE;

1902

exitcode = EX_UNAVAILABLE;

1903

goto end;

1904

}

1905

1906

if(quit_now){

1214

1907

goto end;

1215

1908

}

1216

1909

1217

1910

/* Create the Avahi service browser */

1218

1911

sb = avahi_s_service_browser_new(mc.server, if_index,

1219

AVAHI_PROTO_INET6, "_mandos._tcp",

1912

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1220

1913

NULL, 0, browse_callback, NULL);

1221

1914

if(sb == NULL){

1222

1915

fprintf(stderr, "Failed to create service browser: %s\n",

1223

1916

avahi_strerror(avahi_server_errno(mc.server)));

1224

exitcode = EXIT_FAILURE;

1225

goto end;

1226

}

1227

1228

sigemptyset(&sigterm_action.sa_mask);

1229

ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);

1230

if(ret == -1){

1231

perror("sigaddset");

1232

exitcode = EXIT_FAILURE;

1233

goto end;

1234

}

1235

ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);

1236

if(ret == -1){

1237

perror("sigaction");

1238

exitcode = EXIT_FAILURE;

1239

goto end;

1240

}

1917

exitcode = EX_UNAVAILABLE;

1918

goto end;

1919

}

1920

1921

if(quit_now){

1922

goto end;

1923

}

1241

1924

1242

1925

/* Run the main loop */

1243

1926

1244

1927

if(debug){

1245

1928

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

1246

1929

}

1247

1248

avahi_simple_poll_loop(mc.simple_poll);

1930

1931

ret = avahi_loop_with_timeout(mc.simple_poll,

1932

(int)(retry_interval * 1000));

1933

if(debug){

1934

fprintf(stderr, "avahi_loop_with_timeout exited %s\n",

1935

(ret == 0) ? "successfully" : "with error");

1936

}

1249

1937

1250

1938

end:

1251

1939

1272

1960

if(gpgme_initialized){

1273

1961

gpgme_release(mc.ctx);

1274

1962

}

1275

1276

/* Removes the temp directory used by GPGME */

1963

1964

/* Cleans up the circular linked list of Mandos servers the client

1965

has seen */

1966

if(mc.current_server != NULL){

1967

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

1968

while(mc.current_server != NULL){

1969

server *next = mc.current_server->next;

1970

free(mc.current_server);

1971

mc.current_server = next;

1972

}

1973

}

1974

1975

/* Take down the network interface */

1976

if(take_down_interface){

1977

/* Re-raise priviliges */

1978

errno = 0;

1979

ret = seteuid(0);

1980

if(ret == -1){

1981

perror_plus("seteuid");

1982

}

1983

if(geteuid() == 0){

1984

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1985

if(ret == -1){

1986

perror_plus("ioctl SIOCGIFFLAGS");

1987

} else if(network.ifr_flags & IFF_UP) {

1988

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

1989

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

1990

if(ret == -1){

1991

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1992

}

1993

}

1994

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

1995

if(ret == -1){

1996

perror_plus("close");

1997

}

1998

/* Lower privileges permanently */

1999

errno = 0;

2000

ret = setuid(uid);

2001

if(ret == -1){

2002

perror_plus("setuid");

2003

}

2004

}

2005

}

2006

2007

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

1277

2008

if(tempdir_created){

1278

DIR *d;

1279

struct dirent *direntry;

1280

d = opendir(tempdir);

1281

if(d == NULL){

1282

if(errno != ENOENT){

1283

perror("opendir");

1284

}

1285

} else {

1286

while(true){

1287

direntry = readdir(d);

1288

if(direntry == NULL){

1289

break;

1290

}

1291

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

1292

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

1293

and (direntry->d_name[1] == '\0'

1294

or (direntry->d_name[1] == '.'

1295

and direntry->d_name[2] == '\0'))){

1296

continue;

1297

}

2009

struct dirent **direntries = NULL;

2010

struct dirent *direntry = NULL;

2011

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

2012

alphasort);

2013

if (numentries > 0){

2014

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

2015

direntry = direntries[i];

1298

2016

char *fullname = NULL;

1299

2017

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

1300

2018

direntry->d_name);

1301

2019

if(ret < 0){

1302

perror("asprintf");

2020

perror_plus("asprintf");

1303

2021

continue;

1304

2022

}

1305

2023

ret = remove(fullname);

1309

2027

}

1310

2028

free(fullname);

1311

2029

}

1312

closedir(d);

2030

}

2031

2032

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

2033

free(direntries);

2034

if (numentries == -1){

2035

perror_plus("scandir");

1313

2036

}

1314

2037

ret = rmdir(tempdir);

1315

2038

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

1316

perror("rmdir");

1317

}

2039

perror_plus("rmdir");

2040

}

2041

}

2042

2043

if(quit_now){

2044

sigemptyset(&old_sigterm_action.sa_mask);

2045

old_sigterm_action.sa_handler = SIG_DFL;

2046

ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,

2047

&old_sigterm_action,

2048

NULL));

2049

if(ret == -1){

2050

perror_plus("sigaction");

2051

}

2052

do {

2053

ret = raise(signal_received);

2054

} while(ret != 0 and errno == EINTR);

2055

if(ret != 0){

2056

perror_plus("raise");

2057

abort();

2058

}

2059

TEMP_FAILURE_RETRY(pause());

1318

2060

}

1319

2061

1320

2062

return exitcode;