/mandos/trunk : revision 395

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

strtof(), abort() */

46

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

47

srand(), strtof(), abort() */

48

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

49

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

50

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

63

strtoimax() */

64

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

65

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

66

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

66

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

67

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

68

SIOCSIFFLAGS, if_indextoname(),

69

if_nametoindex(), IF_NAMESIZE */

82

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

83

sigaction(), SIGTERM, sig_atomic_t,

84

raise() */

85

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

86

EX_NOHOST, EX_IOERR, EX_PROTOCOL */

85

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

87

86

88

87

#ifdef __linux__

89

88

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

127

126

static const char mandos_protocol_version[] = "1";

128

127

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

129

128

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

130

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

131

char *connect_to = NULL;

132

129

133

130

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

134

131

typedef struct {

556

553

gnutls_session_t session;

557

554

int pf; /* Protocol family */

558

555

559

errno = 0;

560

561

556

if(quit_now){

562

errno = EINTR;

563

557

return -1;

564

558

}

565

559

572

566

break;

573

567

default:

574

568

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

575

errno = EINVAL;

576

569

return -1;

577

570

}

578

571

588

581

589

582

tcp_sd = socket(pf, SOCK_STREAM, 0);

590

583

if(tcp_sd < 0){

591

int e = errno;

592

584

perror("socket");

593

errno = e;

594

585

goto mandos_end;

595

586

}

596

587

597

588

if(quit_now){

598

errno = EINTR;

599

589

goto mandos_end;

600

590

}

601

591

608

598

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

609

599

}

610

600

if(ret < 0 ){

611

int e = errno;

612

601

perror("inet_pton");

613

errno = e;

614

602

goto mandos_end;

615

603

}

616

604

if(ret == 0){

617

int e = errno;

618

605

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

619

errno = e;

620

606

goto mandos_end;

621

607

}

622

608

if(af == AF_INET6){

630

616

if(if_index == AVAHI_IF_UNSPEC){

631

617

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

632

618

" without a network interface\n");

633

errno = EINVAL;

634

619

goto mandos_end;

635

620

}

636

621

/* Set the network interface number as scope */

643

628

}

644

629

645

630

if(quit_now){

646

errno = EINTR;

647

631

goto mandos_end;

648

632

}

649

633

680

664

}

681

665

682

666

if(quit_now){

683

errno = EINTR;

684

667

goto mandos_end;

685

668

}

686

669

690

673

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

691

674

}

692

675

if(ret < 0){

693

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

694

int e = errno;

695

perror("connect");

696

errno = e;

697

}

676

perror("connect");

698

677

goto mandos_end;

699

678

}

700

679

701

680

if(quit_now){

702

errno = EINTR;

703

681

goto mandos_end;

704

682

}

705

683

710

688

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

711

689

out_size - written));

712

690

if(ret == -1){

713

int e = errno;

714

691

perror("write");

715

errno = e;

716

692

goto mandos_end;

717

693

}

718

694

written += (size_t)ret;

728

704

}

729

705

730

706

if(quit_now){

731

errno = EINTR;

732

707

goto mandos_end;

733

708

}

734

709

}

738

713

}

739

714

740

715

if(quit_now){

741

errno = EINTR;

742

716

goto mandos_end;

743

717

}

744

718

745

719

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

746

720

747

721

if(quit_now){

748

errno = EINTR;

749

722

goto mandos_end;

750

723

}

751

724

752

725

do {

753

726

ret = gnutls_handshake(session);

754

727

if(quit_now){

755

errno = EINTR;

756

728

goto mandos_end;

757

729

}

758

730

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

762

734

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

763

735

gnutls_perror(ret);

764

736

}

765

errno = EPROTO;

766

737

goto mandos_end;

767

738

}

768

739

776

747

while(true){

777

748

778

749

if(quit_now){

779

errno = EINTR;

780

750

goto mandos_end;

781

751

}

782

752

783

753

buffer_capacity = incbuffer(&buffer, buffer_length,

784

754

buffer_capacity);

785

755

if(buffer_capacity == 0){

786

int e = errno;

787

756

perror("incbuffer");

788

errno = e;

789

757

goto mandos_end;

790

758

}

791

759

792

760

if(quit_now){

793

errno = EINTR;

794

761

goto mandos_end;

795

762

}

796

763

809

776

ret = gnutls_handshake(session);

810

777

811

778

if(quit_now){

812

errno = EINTR;

813

779

goto mandos_end;

814

780

}

815

781

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

816

782

if(ret < 0){

817

783

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

818

784

gnutls_perror(ret);

819

errno = EPROTO;

820

785

goto mandos_end;

821

786

}

822

787

break;

824

789

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

825

790

" encrypted session with Mandos server\n");

826

791

gnutls_bye(session, GNUTLS_SHUT_RDWR);

827

errno = EIO;

828

792

goto mandos_end;

829

793

}

830

794

} else {

837

801

}

838

802

839

803

if(quit_now){

840

errno = EINTR;

841

804

goto mandos_end;

842

805

}

843

806

844

807

do {

845

808

ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);

846

809

if(quit_now){

847

errno = EINTR;

848

810

goto mandos_end;

849

811

}

850

812

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

859

821

written = 0;

860

822

while(written < (size_t) decrypted_buffer_size){

861

823

if(quit_now){

862

errno = EINTR;

863

824

goto mandos_end;

864

825

}

865

826

867

828

(size_t)decrypted_buffer_size - written,

868

829

stdout);

869

830

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

870

int e = errno;

871

831

if(debug){

872

832

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

873

833

strerror(errno));

874

834

}

875

errno = e;

876

835

goto mandos_end;

877

836

}

878

837

written += (size_t)ret;

884

843

/* Shutdown procedure */

885

844

886

845

mandos_end:

887

{

888

int e = errno;

889

free(decrypted_buffer);

890

free(buffer);

891

if(tcp_sd >= 0){

892

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

893

}

894

if(ret == -1){

895

if(e == 0){

896

e = errno;

897

}

898

perror("close");

899

}

900

gnutls_deinit(session);

901

if(quit_now){

902

e = EINTR;

903

retval = -1;

904

}

905

errno = e;

846

free(decrypted_buffer);

847

free(buffer);

848

if(tcp_sd >= 0){

849

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

850

}

851

if(ret == -1){

852

perror("close");

853

}

854

gnutls_deinit(session);

855

if(quit_now){

856

retval = -1;

906

857

}

907

858

return retval;

908

859

}

1024

975

errno = old_errno;

1025

976

}

1026

977

1027

/*

1028

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

1029

* corresponds to an acceptable network device.

1030

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

1031

*/

1032

int good_interface(const struct dirent *if_entry){

1033

ssize_t ssret;

1034

char *flagname = NULL;

1035

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

1036

if_entry->d_name);

1037

if(ret < 0){

1038

perror("asprintf");

1039

return 0;

1040

}

1041

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

1042

return 0;

1043

}

1044

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

1045

if(flags_fd == -1){

1046

perror("open");

1047

return 0;

1048

}

1049

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

1050

/* read line from flags_fd */

1051

ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */

1052

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

1053

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

1054

if(flagstring == NULL){

1055

perror("malloc");

1056

close(flags_fd);

1057

return 0;

1058

}

1059

while(to_read > 0){

1060

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

1061

(size_t)to_read));

1062

if(ssret == -1){

1063

perror("read");

1064

free(flagstring);

1065

close(flags_fd);

1066

return 0;

1067

}

1068

to_read -= ssret;

1069

if(ssret == 0){

1070

break;

1071

}

1072

}

1073

close(flags_fd);

1074

intmax_t tmpmax;

1075

char *tmp;

1076

errno = 0;

1077

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

1078

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

1079

and not (isspace(*tmp)))

1080

or tmpmax != (ifreq_flags)tmpmax){

1081

if(debug){

1082

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

1083

flagstring, if_entry->d_name);

1084

}

1085

free(flagstring);

1086

return 0;

1087

}

1088

free(flagstring);

1089

ifreq_flags flags = (ifreq_flags)tmpmax;

1090

/* Reject the loopback device */

1091

if(flags & IFF_LOOPBACK){

1092

if(debug){

1093

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

1094

if_entry->d_name);

1095

}

1096

return 0;

1097

}

1098

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

1099

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

1100

if(debug){

1101

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

1102

if_entry->d_name);

1103

}

1104

return 1;

1105

}

1106

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

1107

if(not (flags & IFF_BROADCAST)){

1108

if(debug){

1109

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

1110

if_entry->d_name);

1111

}

1112

return 0;

1113

}

1114

/* Accept this device */

1115

if(debug){

1116

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

1117

if_entry->d_name);

1118

}

1119

return 1;

1120

}

1121

1122

978

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

1123

979

AvahiSServiceBrowser *sb = NULL;

1124

980

int error;

1126

982

intmax_t tmpmax;

1127

983

char *tmp;

1128

984

int exitcode = EXIT_SUCCESS;

1129

const char *interface = "";

985

const char *interface = "eth0";

1130

986

struct ifreq network;

1131

987

int sd = -1;

1132

988

bool take_down_interface = false;

1133

989

uid_t uid;

1134

990

gid_t gid;

991

char *connect_to = NULL;

1135

992

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

1136

993

bool tempdir_created = false;

1137

994

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1294

1151

if(not debug){

1295

1152

avahi_set_log_function(empty_log);

1296

1153

}

1297

1298

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

1299

struct dirent **direntries;

1300

ret = scandir(sys_class_net, &direntries, good_interface,

1301

alphasort);

1302

if(ret >= 1){

1303

/* Pick the first good interface */

1304

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

1305

if(debug){

1306

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

1307

}

1308

if(interface == NULL){

1309

perror("malloc");

1310

free(direntries);

1311

exitcode = EXIT_FAILURE;

1312

goto end;

1313

}

1314

free(direntries);

1315

} else {

1316

free(direntries);

1317

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

1318

exitcode = EXIT_FAILURE;

1319

goto end;

1320

}

1321

}

1322

1154

1323

1155

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

1324

1156

from the signal handler */

1327

1159

mc.simple_poll = avahi_simple_poll_new();

1328

1160

if(mc.simple_poll == NULL){

1329

1161

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

1330

exitcode = EX_UNAVAILABLE;

1162

exitcode = EXIT_FAILURE;

1331

1163

goto end;

1332

1164

}

1333

1165

1335

1167

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

1336

1168

if(ret == -1){

1337

1169

perror("sigaddset");

1338

exitcode = EX_OSERR;

1170

exitcode = EXIT_FAILURE;

1339

1171

goto end;

1340

1172

}

1341

1173

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

1342

1174

if(ret == -1){

1343

1175

perror("sigaddset");

1344

exitcode = EX_OSERR;

1176

exitcode = EXIT_FAILURE;

1345

1177

goto end;

1346

1178

}

1347

1179

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

1348

1180

if(ret == -1){

1349

1181

perror("sigaddset");

1350

exitcode = EX_OSERR;

1182

exitcode = EXIT_FAILURE;

1351

1183

goto end;

1352

1184

}

1353

1185

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

1357

1189

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

1358

1190

if(ret == -1){

1359

1191

perror("sigaction");

1360

return EX_OSERR;

1192

return EXIT_FAILURE;

1361

1193

}

1362

1194

if(old_sigterm_action.sa_handler != SIG_IGN){

1363

1195

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

1364

1196

if(ret == -1){

1365

1197

perror("sigaction");

1366

exitcode = EX_OSERR;

1198

exitcode = EXIT_FAILURE;

1367

1199

goto end;

1368

1200

}

1369

1201

}

1370

1202

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

1371

1203

if(ret == -1){

1372

1204

perror("sigaction");

1373

return EX_OSERR;

1205

return EXIT_FAILURE;

1374

1206

}

1375

1207

if(old_sigterm_action.sa_handler != SIG_IGN){

1376

1208

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

1377

1209

if(ret == -1){

1378

1210

perror("sigaction");

1379

exitcode = EX_OSERR;

1211

exitcode = EXIT_FAILURE;

1380

1212

goto end;

1381

1213

}

1382

1214

}

1383

1215

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

1384

1216

if(ret == -1){

1385

1217

perror("sigaction");

1386

return EX_OSERR;

1218

return EXIT_FAILURE;

1387

1219

}

1388

1220

if(old_sigterm_action.sa_handler != SIG_IGN){

1389

1221

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

1390

1222

if(ret == -1){

1391

1223

perror("sigaction");

1392

exitcode = EX_OSERR;

1224

exitcode = EXIT_FAILURE;

1393

1225

goto end;

1394

1226

}

1395

1227

}

1396

1228

1397

1229

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

1398

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

1230

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

1399

1231

if_index = (AvahiIfIndex) if_nametoindex(interface);

1400

1232

if(if_index == 0){

1401

1233

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

1402

exitcode = EX_UNAVAILABLE;

1234

exitcode = EXIT_FAILURE;

1403

1235

goto end;

1404

1236

}

1405

1237

1428

1260

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1429

1261

if(sd < 0){

1430

1262

perror("socket");

1431

exitcode = EX_OSERR;

1263

exitcode = EXIT_FAILURE;

1432

1264

#ifdef __linux__

1433

1265

if(restore_loglevel){

1434

1266

ret = klogctl(7, NULL, 0);

1457

1289

}

1458

1290

}

1459

1291

#endif /* __linux__ */

1460

exitcode = EX_OSERR;

1292

exitcode = EXIT_FAILURE;

1461

1293

/* Lower privileges */

1462

1294

errno = 0;

1463

1295

ret = seteuid(uid);

1472

1304

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

1473

1305

if(ret == -1){

1474

1306

take_down_interface = false;

1475

perror("ioctl SIOCSIFFLAGS +IFF_UP");

1476

exitcode = EX_OSERR;

1307

perror("ioctl SIOCSIFFLAGS");

1308

exitcode = EXIT_FAILURE;

1477

1309

#ifdef __linux__

1478

1310

if(restore_loglevel){

1479

1311

ret = klogctl(7, NULL, 0);

1545

1377

ret = init_gnutls_global(pubkey, seckey);

1546

1378

if(ret == -1){

1547

1379

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

1548

exitcode = EX_UNAVAILABLE;

1380

exitcode = EXIT_FAILURE;

1549

1381

goto end;

1550

1382

} else {

1551

1383

gnutls_initialized = true;

1568

1400

1569

1401

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

1570

1402

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

1571

exitcode = EX_UNAVAILABLE;

1403

exitcode = EXIT_FAILURE;

1572

1404

goto end;

1573

1405

} else {

1574

1406

gpgme_initialized = true;

1584

1416

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

1585

1417

if(address == NULL){

1586

1418

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

1587

exitcode = EX_USAGE;

1419

exitcode = EXIT_FAILURE;

1588

1420

goto end;

1589

1421

}

1590

1422

1598

1430

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

1599

1431

or tmpmax != (uint16_t)tmpmax){

1600

1432

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

1601

exitcode = EX_USAGE;

1433

exitcode = EXIT_FAILURE;

1602

1434

goto end;

1603

1435

}

1604

1436

1620

1452

if(quit_now){

1621

1453

goto end;

1622

1454

}

1623

1624

while(not quit_now){

1625

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

1626

if(quit_now or ret == 0){

1627

break;

1628

}

1629

sleep(15);

1630

};

1631

1632

if (not quit_now){

1455

1456

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

1457

if(ret < 0){

1458

exitcode = EXIT_FAILURE;

1459

} else {

1633

1460

exitcode = EXIT_SUCCESS;

1634

1461

}

1635

1636

1462

goto end;

1637

1463

}

1638

1464

1662

1488

if(mc.server == NULL){

1663

1489

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

1664

1490

avahi_strerror(error));

1665

exitcode = EX_UNAVAILABLE;

1491

exitcode = EXIT_FAILURE;

1666

1492

goto end;

1667

1493

}

1668

1494

1677

1503

if(sb == NULL){

1678

1504

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

1679

1505

avahi_strerror(avahi_server_errno(mc.server)));

1680

exitcode = EX_UNAVAILABLE;

1506

exitcode = EXIT_FAILURE;

1681

1507

goto end;

1682

1508

}

1683

1509

1735

1561

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

1736

1562

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

1737

1563

if(ret == -1){

1738

perror("ioctl SIOCSIFFLAGS -IFF_UP");

1564

perror("ioctl SIOCSIFFLAGS");

1739

1565

}

1740

1566

}

1741

1567

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