/mandos/trunk : revision 349

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

73

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

74

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

74

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

75

setgid() */

76

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

77

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

80

argp_parse(), ARGP_KEY_ARG,

81

ARGP_KEY_END, ARGP_ERR_UNKNOWN */

82

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

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

83

sigaction(), SIGTERM, sigaction,

84

sig_atomic_t */

85

86

#ifdef __linux__

87

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

164

*/

165

static bool init_gpgme(const char *seckey,

166

const char *pubkey, const char *tempdir){

167

int ret;

167

168

gpgme_error_t rc;

168

169

gpgme_engine_info_t engine_info;

169

170

172

173

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

173

174

*/

174

175

bool import_key(const char *filename){

175

int ret;

176

int fd;

177

gpgme_data_t pgp_data;

178

249

return false;

250

}

251

252

return true;

252

return true;

253

}

254

255

/*

514

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

515

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

516

517

sig_atomic_t quit_now = 0;

518

int signal_received = 0;

519

520

517

/* Called when a Mandos server is found */

521

518

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

522

519

AvahiIfIndex if_index,

523

520

int af){

524

int ret, tcp_sd = -1;

521

int ret, tcp_sd;

525

522

ssize_t sret;

526

523

union {

527

524

struct sockaddr_in in;

531

528

char *decrypted_buffer;

532

529

size_t buffer_length = 0;

533

530

size_t buffer_capacity = 0;

531

ssize_t decrypted_buffer_size;

534

532

size_t written;

535

533

int retval = 0;

536

534

gnutls_session_t session;

537

535

int pf; /* Protocol family */

538

536

539

if(quit_now){

540

return -1;

541

}

542

543

537

switch(af){

544

538

case AF_INET6:

545

539

pf = PF_INET6;

565

559

tcp_sd = socket(pf, SOCK_STREAM, 0);

566

560

if(tcp_sd < 0){

567

561

perror("socket");

568

retval = -1;

569

goto mandos_end;

570

}

571

572

if(quit_now){

573

goto mandos_end;

562

return -1;

574

563

}

575

564

576

565

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

583

572

}

584

573

if(ret < 0 ){

585

574

perror("inet_pton");

586

retval = -1;

587

goto mandos_end;

575

return -1;

588

576

}

589

577

if(ret == 0){

590

578

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

591

retval = -1;

592

goto mandos_end;

579

return -1;

593

580

}

594

581

if(af == AF_INET6){

595

582

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

602

589

if(if_index == AVAHI_IF_UNSPEC){

603

590

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

604

591

" without a network interface\n");

605

retval = -1;

606

goto mandos_end;

592

return -1;

607

593

}

608

594

/* Set the network interface number as scope */

609

595

to.in6.sin6_scope_id = (uint32_t)if_index;

614

600

-Wunreachable-code */

615

601

}

616

602

617

if(quit_now){

618

goto mandos_end;

619

}

620

621

603

if(debug){

622

604

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

623

605

char interface[IF_NAMESIZE];

650

632

}

651

633

}

652

634

653

if(quit_now){

654

goto mandos_end;

655

}

656

657

635

if(af == AF_INET6){

658

636

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

659

637

} else {

661

639

}

662

640

if(ret < 0){

663

641

perror("connect");

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

642

return -1;

670

643

}

671

644

672

645

const char *out = mandos_protocol_version;

691

664

break;

692

665

}

693

666

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

698

667

}

699

668

700

669

if(debug){

701

670

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

702

671

}

703

672

704

if(quit_now){

705

goto mandos_end;

706

}

707

708

673

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

709

674

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

675

do{

715

676

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

719

677

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

720

678

721

679

if(ret != GNUTLS_E_SUCCESS){

735

693

}

736

694

737

695

while(true){

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

743

696

buffer_capacity = incbuffer(&buffer, buffer_length,

744

697

buffer_capacity);

745

698

if(buffer_capacity == 0){

748

701

goto mandos_end;

749

702

}

750

703

751

if(quit_now){

752

goto mandos_end;

753

}

754

755

704

sret = gnutls_record_recv(session, buffer+buffer_length,

756

705

BUFFER_SIZE);

757

706

if(sret == 0){

763

712

case GNUTLS_E_AGAIN:

764

713

break;

765

714

case GNUTLS_E_REHANDSHAKE:

766

do {

715

do{

767

716

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

772

717

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

773

718

if(ret < 0){

774

719

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

793

738

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

794

739

}

795

740

796

if(quit_now){

797

goto mandos_end;

798

}

799

800

741

gnutls_bye(session, GNUTLS_SHUT_RDWR);

801

742

802

if(quit_now){

803

goto mandos_end;

804

}

805

806

743

if(buffer_length > 0){

807

ssize_t decrypted_buffer_size;

808

744

decrypted_buffer_size = pgp_packet_decrypt(buffer,

809

745

buffer_length,

810

746

&decrypted_buffer);

811

747

if(decrypted_buffer_size >= 0){

812

813

748

written = 0;

814

749

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

819

750

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

820

751

(size_t)decrypted_buffer_size - written,

821

752

stdout);

841

772

842

773

mandos_end:

843

774

free(buffer);

844

if(tcp_sd >= 0){

845

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

846

}

775

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

847

776

if(ret == -1){

848

777

perror("close");

849

778

}

850

779

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

854

780

return retval;

855

781

}

856

782

873

799

/* Called whenever a service has been resolved successfully or

874

800

timed out */

875

801

876

if(quit_now){

877

return;

878

}

879

880

802

switch(event){

881

803

default:

882

804

case AVAHI_RESOLVER_FAILURE:

919

841

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

920

842

is removed from the LAN */

921

843

922

if(quit_now){

923

return;

924

}

925

926

844

switch(event){

927

845

default:

928

846

case AVAHI_BROWSER_FAILURE:

957

875

}

958

876

}

959

877

878

sig_atomic_t quit_now = 0;

879

960

880

/* stop main loop after sigterm has been called */

961

static void handle_sigterm(int sig){

881

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

962

882

if(quit_now){

963

883

return;

964

884

}

965

885

quit_now = 1;

966

signal_received = sig;

967

886

int old_errno = errno;

968

887

if(mc.simple_poll != NULL){

969

888

avahi_simple_poll_quit(mc.simple_poll);

980

899

int exitcode = EXIT_SUCCESS;

981

900

const char *interface = "eth0";

982

901

struct ifreq network;

983

int sd = -1;

984

bool take_down_interface = false;

902

int sd;

985

903

uid_t uid;

986

904

gid_t gid;

987

905

char *connect_to = NULL;

1130

1048

exitcode = EXIT_FAILURE;

1131

1049

goto end;

1132

1050

}

1133

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

1134

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

1135

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

1136

*/

1137

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

1138

if(ret == -1){

1139

perror("sigaction");

1140

return EXIT_FAILURE;

1141

}

1142

if(old_sigterm_action.sa_handler != SIG_IGN){

1143

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

1144

if(ret == -1){

1145

perror("sigaction");

1146

exitcode = EXIT_FAILURE;

1147

goto end;

1148

}

1149

}

1150

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

1151

if(ret == -1){

1152

perror("sigaction");

1153

return EXIT_FAILURE;

1154

}

1155

if(old_sigterm_action.sa_handler != SIG_IGN){

1156

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

1157

if(ret == -1){

1158

perror("sigaction");

1159

exitcode = EXIT_FAILURE;

1160

goto end;

1161

}

1162

}

1163

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

1164

if(ret == -1){

1165

perror("sigaction");

1166

return EXIT_FAILURE;

1167

}

1168

if(old_sigterm_action.sa_handler != SIG_IGN){

1169

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

1170

if(ret == -1){

1171

perror("sigaction");

1172

exitcode = EXIT_FAILURE;

1173

goto end;

1174

}

1175

}

1051

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

1052

if(ret == -1){

1053

perror("sigaction");

1054

exitcode = EXIT_FAILURE;

1055

goto end;

1056

}

1176

1057

1177

1058

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

1178

1059

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

1179

if_index = (AvahiIfIndex) if_nametoindex(interface);

1180

if(if_index == 0){

1181

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

1182

exitcode = EXIT_FAILURE;

1183

goto end;

1184

}

1185

1186

if(quit_now){

1187

goto end;

1188

}

1189

1190

1060

#ifdef __linux__

1191

1061

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1192

1062

messages to mess up the prompt */

1229

1099

}

1230

1100

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

1231

1101

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

1233

1102

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

1234

1103

if(ret == -1){

1235

take_down_interface = false;

1236

1104

perror("ioctl SIOCSIFFLAGS");

1237

1105

exitcode = EXIT_FAILURE;

1238

1106

#ifdef __linux__

1260

1128

perror("nanosleep");

1261

1129

}

1262

1130

}

1263

if(not take_down_interface){

1264

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

1265

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

1266

if(ret == -1){

1267

perror("close");

1268

}

1131

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

1132

if(ret == -1){

1133

perror("close");

1269

1134

}

1270

1135

#ifdef __linux__

1271

1136

if(restore_loglevel){

1278

1143

#endif /* __linux__ */

1279

1144

}

1280

1145

1281

if(quit_now){

1282

goto end;

1283

}

1284

1285

1146

uid = getuid();

1286

1147

gid = getgid();

1287

1148

1288

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

1289

1149

errno = 0;

1290

ret = setgid(gid);

1150

setgid(gid);

1291

1151

if(ret == -1){

1292

1152

perror("setgid");

1293

1153

}

1294

1154

1295

/* Drop user privileges */

1296

errno = 0;

1297

/* Will we need privileges later? */

1298

if(take_down_interface){

1299

/* Drop user privileges temporarily */

1300

ret = seteuid(uid);

1301

if(ret == -1){

1302

perror("seteuid");

1303

}

1304

} else {

1305

/* Drop user privileges permanently */

1306

ret = setuid(uid);

1307

if(ret == -1){

1308

perror("setuid");

1309

}

1310

}

1311

1312

if(quit_now){

1313

goto end;

1155

ret = setuid(uid);

1156

if(ret == -1){

1157

perror("setuid");

1314

1158

}

1315

1159

1316

1160

ret = init_gnutls_global(pubkey, seckey);

1322

1166

gnutls_initialized = true;

1323

1167

}

1324

1168

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1330

1169

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1332

1170

perror("mkdtemp");

1333

1171

goto end;

1334

1172

}

1335

1336

if(quit_now){

1337

goto end;

1338

}

1173

tempdir_created = true;

1339

1174

1340

1175

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

1341

1176

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

1345

1180

gpgme_initialized = true;

1346

1181

}

1347

1182

1348

if(quit_now){

1349

goto end;

1183

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

1184

if_index = (AvahiIfIndex) if_nametoindex(interface);

1185

if(if_index == 0){

1186

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

1187

exitcode = EXIT_FAILURE;

1188

goto end;

1189

}

1350

1190

}

1351

1191

1352

1192

if(connect_to != NULL){

1358

1198

exitcode = EXIT_FAILURE;

1359

1199

goto end;

1360

1200

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1366

1201

uint16_t port;

1367

1202

errno = 0;

1368

1203

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

1372

1207

exitcode = EXIT_FAILURE;

1373

1208

goto end;

1374

1209

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1380

1210

port = (uint16_t)tmpmax;

1381

1211

*address = '\0';

1382

1212

address = connect_to;

1387

1217

} else {

1388

1218

af = AF_INET;

1389

1219

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1395

1220

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

1396

1221

if(ret < 0){

1397

1222

exitcode = EXIT_FAILURE;

1400

1225

}

1401

1226

goto end;

1402

1227

}

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1228

1408

1229

{

1409

1230

AvahiServerConfig config;

1410

1231

/* Do not publish any local Zeroconf records */

1431

1252

goto end;

1432

1253

}

1433

1254

1434

if(quit_now){

1435

goto end;

1436

}

1437

1438

1255

/* Create the Avahi service browser */

1439

1256

sb = avahi_s_service_browser_new(mc.server, if_index,

1440

1257

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1446

1263

goto end;

1447

1264

}

1448

1265

1449

if(quit_now){

1450

goto end;

1451

}

1452

1453

1266

/* Run the main loop */

1454

1267

1455

1268

if(debug){

1484

1297

gpgme_release(mc.ctx);

1485

1298

}

1486

1299

1487

/* Take down the network interface */

1488

if(take_down_interface){

1489

/* Re-raise priviliges */

1490

errno = 0;

1491

ret = seteuid(0);

1492

if(ret == -1){

1493

perror("seteuid");

1494

}

1495

if(geteuid() == 0){

1496

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

1497

if(ret == -1){

1498

perror("ioctl SIOCGIFFLAGS");

1499

} else if(network.ifr_flags & IFF_UP) {

1500

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

1501

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

1502

if(ret == -1){

1503

perror("ioctl SIOCSIFFLAGS");

1504

}

1505

}

1506

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

1507

if(ret == -1){

1508

perror("close");

1509

}

1510

/* Lower privileges, permanently this time */

1511

errno = 0;

1512

ret = setuid(uid);

1513

if(ret == -1){

1514

perror("setuid");

1515

}

1516

}

1517

}

1518

1519

1300

/* Removes the temp directory used by GPGME */

1520

1301

if(tempdir_created){

1521

1302

DIR *d;

1560

1341

}

1561

1342

}

1562

1343

1563

if(quit_now){

1564

sigemptyset(&old_sigterm_action.sa_mask);

1565

old_sigterm_action.sa_handler = SIG_DFL;

1566

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

1567

if(ret == -1){

1568

perror("sigaction");

1569

}

1570

raise(signal_received);

1571

}

1572

1573

1344

return exitcode;

1574

1345

}