/mandos/trunk : revision 366

71

INET_ADDRSTRLEN, INET6_ADDRSTRLEN

72

*/

73

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

74

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

74

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

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, sigaction,

84

sig_atomic_t */

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

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;

168

167

gpgme_error_t rc;

169

168

gpgme_engine_info_t engine_info;

170

169

173

172

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

174

173

*/

175

174

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

517

520

/* Called when a Mandos server is found */

518

521

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

519

522

AvahiIfIndex if_index,

520

523

int af){

521

int ret, tcp_sd;

524

int ret, tcp_sd = -1;

522

525

ssize_t sret;

523

526

union {

524

527

struct sockaddr_in in;

528

531

char *decrypted_buffer;

529

532

size_t buffer_length = 0;

530

533

size_t buffer_capacity = 0;

531

ssize_t decrypted_buffer_size;

532

534

size_t written;

533

535

int retval = 0;

534

536

gnutls_session_t session;

535

537

int pf; /* Protocol family */

536

538

539

if(quit_now){

540

return -1;

541

}

542

537

543

switch(af){

538

544

case AF_INET6:

539

545

pf = PF_INET6;

559

565

tcp_sd = socket(pf, SOCK_STREAM, 0);

560

566

if(tcp_sd < 0){

561

567

perror("socket");

562

return -1;

568

retval = -1;

569

goto mandos_end;

570

}

571

572

if(quit_now){

573

goto mandos_end;

563

574

}

564

575

565

576

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

572

583

}

573

584

if(ret < 0 ){

574

585

perror("inet_pton");

575

return -1;

586

retval = -1;

587

goto mandos_end;

576

588

}

577

589

if(ret == 0){

578

590

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

579

return -1;

591

retval = -1;

592

goto mandos_end;

580

593

}

581

594

if(af == AF_INET6){

582

595

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

589

602

if(if_index == AVAHI_IF_UNSPEC){

590

603

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

591

604

" without a network interface\n");

592

return -1;

605

retval = -1;

606

goto mandos_end;

593

607

}

594

608

/* Set the network interface number as scope */

595

609

to.in6.sin6_scope_id = (uint32_t)if_index;

600

614

-Wunreachable-code */

601

615

}

602

616

617

if(quit_now){

618

goto mandos_end;

619

}

620

603

621

if(debug){

604

622

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

605

623

char interface[IF_NAMESIZE];

632

650

}

633

651

}

634

652

653

if(quit_now){

654

goto mandos_end;

655

}

656

635

657

if(af == AF_INET6){

636

658

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

637

659

} else {

639

661

}

640

662

if(ret < 0){

641

663

perror("connect");

642

return -1;

664

retval = -1;

665

goto mandos_end;

666

}

667

668

if(quit_now){

669

goto mandos_end;

643

670

}

644

671

645

672

const char *out = mandos_protocol_version;

664

691

break;

665

692

}

666

693

}

694

695

if(quit_now){

696

goto mandos_end;

697

}

667

698

}

668

699

669

700

if(debug){

670

701

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

671

702

}

672

703

704

if(quit_now){

705

goto mandos_end;

706

}

707

673

708

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

674

709

675

do{

710

if(quit_now){

711

goto mandos_end;

712

}

713

714

do {

676

715

ret = gnutls_handshake(session);

716

if(quit_now){

717

goto mandos_end;

718

}

677

719

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

678

720

679

721

if(ret != GNUTLS_E_SUCCESS){

693

735

}

694

736

695

737

while(true){

738

739

if(quit_now){

740

goto mandos_end;

741

}

742

696

743

buffer_capacity = incbuffer(&buffer, buffer_length,

697

744

buffer_capacity);

698

745

if(buffer_capacity == 0){

701

748

goto mandos_end;

702

749

}

703

750

751

if(quit_now){

752

goto mandos_end;

753

}

754

704

755

sret = gnutls_record_recv(session, buffer+buffer_length,

705

756

BUFFER_SIZE);

706

757

if(sret == 0){

712

763

case GNUTLS_E_AGAIN:

713

764

break;

714

765

case GNUTLS_E_REHANDSHAKE:

715

do{

766

do {

716

767

ret = gnutls_handshake(session);

768

769

if(quit_now){

770

goto mandos_end;

771

}

717

772

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

718

773

if(ret < 0){

719

774

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

738

793

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

739

794

}

740

795

796

if(quit_now){

797

goto mandos_end;

798

}

799

741

800

gnutls_bye(session, GNUTLS_SHUT_RDWR);

742

801

802

if(quit_now){

803

goto mandos_end;

804

}

805

743

806

if(buffer_length > 0){

807

ssize_t decrypted_buffer_size;

744

808

decrypted_buffer_size = pgp_packet_decrypt(buffer,

745

809

buffer_length,

746

810

&decrypted_buffer);

747

811

if(decrypted_buffer_size >= 0){

812

748

813

written = 0;

749

814

while(written < (size_t) decrypted_buffer_size){

815

if(quit_now){

816

goto mandos_end;

817

}

818

750

819

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

751

820

(size_t)decrypted_buffer_size - written,

752

821

stdout);

772

841

773

842

mandos_end:

774

843

free(buffer);

775

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

844

if(tcp_sd >= 0){

845

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

846

}

776

847

if(ret == -1){

777

848

perror("close");

778

849

}

779

850

gnutls_deinit(session);

851

if(quit_now){

852

retval = -1;

853

}

780

854

return retval;

781

855

}

782

856

799

873

/* Called whenever a service has been resolved successfully or

800

874

timed out */

801

875

876

if(quit_now){

877

return;

878

}

879

802

880

switch(event){

803

881

default:

804

882

case AVAHI_RESOLVER_FAILURE:

841

919

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

842

920

is removed from the LAN */

843

921

922

if(quit_now){

923

return;

924

}

925

844

926

switch(event){

845

927

default:

846

928

case AVAHI_BROWSER_FAILURE:

875

957

}

876

958

}

877

959

878

sig_atomic_t quit_now = 0;

879

880

960

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

881

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

961

static void handle_sigterm(int sig){

882

962

if(quit_now){

883

963

return;

884

964

}

885

965

quit_now = 1;

966

signal_received = sig;

886

967

int old_errno = errno;

887

968

if(mc.simple_poll != NULL){

888

969

avahi_simple_poll_quit(mc.simple_poll);

900

981

const char *interface = "eth0";

901

982

struct ifreq network;

902

983

int sd = -1;

903

bool interface_taken_up = false;

984

bool take_down_interface = false;

904

985

uid_t uid;

905

986

gid_t gid;

906

987

char *connect_to = NULL;

1049

1130

exitcode = EXIT_FAILURE;

1050

1131

goto end;

1051

1132

}

1052

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

1053

if(ret == -1){

1054

perror("sigaction");

1055

exitcode = EXIT_FAILURE;

1056

goto end;

1057

}

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

}

1058

1176

1059

1177

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

1060

1178

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

1061

1190

#ifdef __linux__

1062

1191

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1063

1192

messages to mess up the prompt */

1100

1229

}

1101

1230

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

1102

1231

network.ifr_flags |= IFF_UP;

1232

take_down_interface = true;

1103

1233

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

1104

1234

if(ret == -1){

1235

take_down_interface = false;

1105

1236

perror("ioctl SIOCSIFFLAGS");

1106

1237

exitcode = EXIT_FAILURE;

1107

1238

#ifdef __linux__

1114

1245

#endif /* __linux__ */

1115

1246

goto end;

1116

1247

}

1117

interface_taken_up = true;

1118

1248

}

1119

1249

/* sleep checking until interface is running */

1120

1250

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

1130

1260

perror("nanosleep");

1131

1261

}

1132

1262

}

1133

if(not interface_taken_up){

1263

if(not take_down_interface){

1264

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

1134

1265

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

1135

1266

if(ret == -1){

1136

1267

perror("close");

1147

1278

#endif /* __linux__ */

1148

1279

}

1149

1280

1281

if(quit_now){

1282

goto end;

1283

}

1284

1150

1285

uid = getuid();

1151

1286

gid = getgid();

1152

1287

1288

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

1153

1289

errno = 0;

1154

setgid(gid);

1290

ret = setgid(gid);

1155

1291

if(ret == -1){

1156

1292

perror("setgid");

1157

1293

}

1158

1294

1159

ret = setuid(uid);

1160

if(ret == -1){

1161

perror("setuid");

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;

1162

1314

}

1163

1315

1164

1316

ret = init_gnutls_global(pubkey, seckey);

1170

1322

gnutls_initialized = true;

1171

1323

}

1172

1324

1325

if(quit_now){

1326

goto end;

1327

}

1328

1329

tempdir_created = true;

1173

1330

if(mkdtemp(tempdir) == NULL){

1331

tempdir_created = false;

1174

1332

perror("mkdtemp");

1175

1333

goto end;

1176

1334

}

1177

tempdir_created = true;

1335

1336

if(quit_now){

1337

goto end;

1338

}

1178

1339

1179

1340

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

1180

1341

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

1184

1345

gpgme_initialized = true;

1185

1346

}

1186

1347

1187

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

1188

if_index = (AvahiIfIndex) if_nametoindex(interface);

1189

if(if_index == 0){

1190

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

1191

exitcode = EXIT_FAILURE;

1192

goto end;

1193

}

1348

if(quit_now){

1349

goto end;

1194

1350

}

1195

1351

1196

1352

if(connect_to != NULL){

1202

1358

exitcode = EXIT_FAILURE;

1203

1359

goto end;

1204

1360

}

1361

1362

if(quit_now){

1363

goto end;

1364

}

1365

1205

1366

uint16_t port;

1206

1367

errno = 0;

1207

1368

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

1211

1372

exitcode = EXIT_FAILURE;

1212

1373

goto end;

1213

1374

}

1375

1376

if(quit_now){

1377

goto end;

1378

}

1379

1214

1380

port = (uint16_t)tmpmax;

1215

1381

*address = '\0';

1216

1382

address = connect_to;

1221

1387

} else {

1222

1388

af = AF_INET;

1223

1389

}

1390

1391

if(quit_now){

1392

goto end;

1393

}

1394

1224

1395

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

1225

1396

if(ret < 0){

1226

1397

exitcode = EXIT_FAILURE;

1229

1400

}

1230

1401

goto end;

1231

1402

}

1232

1403

1404

if(quit_now){

1405

goto end;

1406

}

1407

1233

1408

{

1234

1409

AvahiServerConfig config;

1235

1410

/* Do not publish any local Zeroconf records */

1256

1431

goto end;

1257

1432

}

1258

1433

1434

if(quit_now){

1435

goto end;

1436

}

1437

1259

1438

/* Create the Avahi service browser */

1260

1439

sb = avahi_s_service_browser_new(mc.server, if_index,

1261

1440

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

1267

1446

goto end;

1268

1447

}

1269

1448

1449

if(quit_now){

1450

goto end;

1451

}

1452

1270

1453

/* Run the main loop */

1271

1454

1272

1455

if(debug){

1302

1485

}

1303

1486

1304

1487

/* Take down the network interface */

1305

if(interface_taken_up){

1306

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

1488

if(take_down_interface){

1489

/* Re-raise priviliges */

1490

errno = 0;

1491

ret = seteuid(0);

1307

1492

if(ret == -1){

1308

perror("ioctl SIOCGIFFLAGS");

1309

} else if(network.ifr_flags & IFF_UP) {

1310

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

1311

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

1312

if(ret == -1){

1313

perror("ioctl SIOCSIFFLAGS");

1314

}

1493

perror("seteuid");

1315

1494

}

1316

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

1317

if(ret == -1){

1318

perror("close");

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

}

1319

1516

}

1320

1517

}

1321

1518

1363

1560

}

1364

1561

}

1365

1562

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

1366

1573

return exitcode;

1367

1574

}