/mandos/trunk : revision 752

9

* "browse_callback", and parts of "main".

10

*

11

* Everything else is

12

13

12

13

14

*

15

* This program is free software: you can redistribute it and/or

16

* modify it under the terms of the GNU General Public License as

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

43

stdout, ferror() */

44

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

45

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

46

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

57

#include <sys/socket.h> /* socket(), struct sockaddr_in6,

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

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

61

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

62

*/

63

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

73

*/

74

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

75

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

76

setgid(), pause(), _exit() */

76

setgid(), pause(), _exit(),

77

unlinkat() */

77

78

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

78

79

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

79

80

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

141

142

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

142

143

char *connect_to = NULL;

143

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

144

146

uid_t uid = 65534;

145

147

gid_t gid = 65534;

146

148

183

185

perror(print_text);

184

186

}

185

187

186

__attribute__((format (gnu_printf, 2, 3)))

188

__attribute__((format (gnu_printf, 2, 3), nonnull))

187

189

int fprintf_plus(FILE *stream, const char *format, ...){

188

190

va_list ap;

189

191

va_start (ap, format);

198

200

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

199

201

* "buffer_length" is how much is already used.

200

202

*/

203

__attribute__((nonnull, warn_unused_result))

201

204

size_t incbuffer(char **buffer, size_t buffer_length,

202

205

size_t buffer_capacity){

203

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

216

219

}

217

220

218

221

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

222

__attribute__((nonnull, warn_unused_result))

219

223

bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,

220

224

int af, server **current_server){

221

225

int ret;

230

234

.af = af };

231

235

if(new_server->ip == NULL){

232

236

perror_plus("strdup");

237

free(new_server);

233

238

return false;

234

239

}

235

240

ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

236

241

if(ret == -1){

237

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

free((char *)(new_server->ip));

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

238

252

return false;

239

253

}

240

254

/* Special case of first server */

242

256

new_server->next = new_server;

243

257

new_server->prev = new_server;

244

258

*current_server = new_server;

245

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

246

259

} else {

260

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

247

261

new_server->next = *current_server;

248

262

new_server->prev = (*current_server)->prev;

249

263

new_server->prev->next = new_server;

255

269

/*

256

270

* Initialize GPGME.

257

271

*/

258

static bool init_gpgme(const char *seckey, const char *pubkey,

259

const char *tempdir, mandos_context *mc){

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

260

277

gpgme_error_t rc;

261

278

gpgme_engine_info_t engine_info;

262

279

263

280

/*

264

281

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

265

282

*/

266

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

267

284

int ret;

268

285

int fd;

269

286

gpgme_data_t pgp_data;

350

367

* Decrypt OpenPGP data.

351

368

* Returns -1 on error

352

369

*/

370

__attribute__((nonnull, warn_unused_result))

353

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

354

372

size_t crypto_size,

355

373

char **plaintext,

475

493

return plaintext_length;

476

494

}

477

495

478

static const char * safer_gnutls_strerror(int value){

496

__attribute__((warn_unused_result, const))

497

static const char *safe_string(const char *str){

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

479

505

const char *ret = gnutls_strerror(value);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

506

return safe_string(ret);

483

507

}

484

508

485

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

486

511

static void debuggnutls(__attribute__((unused)) int level,

487

512

const char* string){

488

513

fprintf_plus(stderr, "GnuTLS: %s", string);

489

514

}

490

515

516

__attribute__((nonnull, warn_unused_result))

491

517

static int init_gnutls_global(const char *pubkeyfilename,

492

518

const char *seckeyfilename,

493

519

mandos_context *mc){

494

520

int ret;

521

unsigned int uret;

495

522

496

523

if(debug){

497

524

fprintf_plus(stderr, "Initializing GnuTLS\n");

548

575

safer_gnutls_strerror(ret));

549

576

goto globalfail;

550

577

}

578

if(mc->dh_bits == 0){

579

/* Find out the optimal number of DH bits */

580

/* Try to read the private key file */

581

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

585

while(true){

586

buffer_capacity = incbuffer((char **)&buffer.data,

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

590

perror_plus("incbuffer");

591

free(buffer.data);

592

buffer.data = NULL;

593

break;

594

}

595

ssize_t bytes_read = read(secfile, buffer.data + buffer.size,

596

BUFFER_SIZE);

597

/* EOF */

598

if(bytes_read == 0){

599

break;

600

}

601

/* check bytes_read for failure */

602

if(bytes_read < 0){

603

perror_plus("read");

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

/* If successful, use buffer to parse private key */

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

" structure: %s", safer_gnutls_strerror(ret));

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

627

if(ret != GNUTLS_E_SUCCESS){

628

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

629

safer_gnutls_strerror(ret));

630

privkey = NULL;

631

}

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

/* Use private key to suggest an appropriate sec_param */

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

fprintf_plus(stderr, "This OpenPGP key implies using a"

640

" GnuTLS security parameter \"%s\".\n",

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

644

}

645

}

646

}

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

650

if(debug){

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

653

safe_string(gnutls_sec_param_get_name

654

(sec_param)));

655

}

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

663

" implies %u DH bits; using that.\n",

664

safe_string(gnutls_sec_param_get_name

665

(sec_param)),

666

mc->dh_bits);

667

}

668

} else {

669

fprintf_plus(stderr, "Failed to get implied number of DH"

670

" bits for security parameter \"%s\"): %s\n",

671

safe_string(gnutls_sec_param_get_name(sec_param)),

672

safer_gnutls_strerror(ret));

673

goto globalfail;

674

}

675

} else if(debug){

676

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

677

mc->dh_bits);

678

}

551

679

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

552

680

if(ret != GNUTLS_E_SUCCESS){

553

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

554

safer_gnutls_strerror(ret));

681

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u bits):"

682

" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));

555

683

goto globalfail;

556

684

}

557

685

567

695

return -1;

568

696

}

569

697

698

__attribute__((nonnull, warn_unused_result))

570

699

static int init_gnutls_session(gnutls_session_t *session,

571

700

mandos_context *mc){

572

701

int ret;

629

758

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

630

759

631

760

/* Called when a Mandos server is found */

761

__attribute__((nonnull, warn_unused_result))

632

762

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

633

763

AvahiIfIndex if_index,

634

764

int af, mandos_context *mc){

740

870

goto mandos_end;

741

871

}

742

872

if(af == AF_INET6){

743

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

873

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

744

874

if(IN6_IS_ADDR_LINKLOCAL

745

875

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

746

876

if(if_index == AVAHI_IF_UNSPEC){

809

939

sizeof(struct sockaddr_in));

810

940

}

811

941

if(ret < 0){

812

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

942

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

813

943

int e = errno;

814

944

perror_plus("connect");

815

945

errno = e;

1030

1160

return retval;

1031

1161

}

1032

1162

1163

__attribute__((nonnull))

1033

1164

static void resolve_callback(AvahiSServiceResolver *r,

1034

1165

AvahiIfIndex interface,

1035

1166

AvahiProtocol proto,

1043

1174

AVAHI_GCC_UNUSED AvahiStringList *txt,

1044

1175

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1045

1176

flags,

1046

void* mc){

1177

void *mc){

1047

1178

if(r == NULL){

1048

1179

return;

1049

1180

}

1052

1183

timed out */

1053

1184

1054

1185

if(quit_now){

1186

avahi_s_service_resolver_free(r);

1055

1187

return;

1056

1188

}

1057

1189

1102

1234

const char *domain,

1103

1235

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1104

1236

flags,

1105

void* mc){

1237

void *mc){

1106

1238

if(b == NULL){

1107

1239

return;

1108

1240

}

1168

1300

errno = old_errno;

1169

1301

}

1170

1302

1303

__attribute__((nonnull, warn_unused_result))

1171

1304

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

1172

1305

int ret;

1173

1306

error_t ret_errno;

1192

1325

return true;

1193

1326

}

1194

1327

1328

__attribute__((nonnull, warn_unused_result))

1195

1329

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

1196

1330

1197

1331

/* Reject the loopback device */

1239

1373

* corresponds to an acceptable network device.

1240

1374

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

1241

1375

*/

1376

__attribute__((nonnull, warn_unused_result))

1242

1377

int good_interface(const struct dirent *if_entry){

1243

1378

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

1244

1379

return 0;

1262

1397

/*

1263

1398

* This function determines if a network interface is up.

1264

1399

*/

1400

__attribute__((nonnull, warn_unused_result))

1265

1401

bool interface_is_up(const char *interface){

1266

1402

struct ifreq ifr;

1267

1403

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

1278

1414

/*

1279

1415

* This function determines if a network interface is running

1280

1416

*/

1417

__attribute__((nonnull, warn_unused_result))

1281

1418

bool interface_is_running(const char *interface){

1282

1419

struct ifreq ifr;

1283

1420

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

1291

1428

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

1292

1429

}

1293

1430

1431

__attribute__((nonnull, pure, warn_unused_result))

1294

1432

int notdotentries(const struct dirent *direntry){

1295

1433

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

1296

1434

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

1303

1441

}

1304

1442

1305

1443

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

1444

__attribute__((nonnull, warn_unused_result))

1306

1445

int runnable_hook(const struct dirent *direntry){

1307

1446

int ret;

1308

1447

size_t sret;

1316

1455

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

1317

1456

"abcdefghijklmnopqrstuvwxyz"

1318

1457

"0123456789"

1319

"_-");

1458

"_.-");

1320

1459

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

1321

1460

/* Contains non-allowed characters */

1322

1461

if(debug){

1326

1465

return 0;

1327

1466

}

1328

1467

1329

char *fullname = NULL;

1330

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1331

if(ret < 0){

1332

perror_plus("asprintf");

1333

return 0;

1334

}

1335

1336

ret = stat(fullname, &st);

1468

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

1337

1469

if(ret == -1){

1338

1470

if(debug){

1339

1471

perror_plus("Could not stat hook");

1363

1495

return 1;

1364

1496

}

1365

1497

1498

__attribute__((nonnull, warn_unused_result))

1366

1499

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1367

1500

mandos_context *mc){

1368

1501

int ret;

1372

1505

1373

1506

while(true){

1374

1507

if(mc->current_server == NULL){

1375

if (debug){

1508

if(debug){

1376

1509

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

1377

1510

" No timeout!\n");

1378

1511

}

1379

1512

ret = avahi_simple_poll_iterate(s, -1);

1380

1513

} else {

1381

if (debug){

1514

if(debug){

1382

1515

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

1383

1516

" it, or wait\n");

1384

1517

}

1401

1534

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

1402

1535

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

1403

1536

1404

if (debug){

1537

if(debug){

1405

1538

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

1406

1539

block_time);

1407

1540

}

1429

1562

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

1430

1563

}

1431

1564

if(ret != 0){

1432

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

1565

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

1433

1566

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

1434

1567

}

1435

1568

}

1437

1570

}

1438

1571

1439

1572

/* Set effective uid to 0, return errno */

1573

__attribute__((warn_unused_result))

1440

1574

error_t raise_privileges(void){

1441

1575

error_t old_errno = errno;

1442

1576

error_t ret_errno = 0;

1443

1577

if(seteuid(0) == -1){

1444

1578

ret_errno = errno;

1445

perror_plus("seteuid");

1446

1579

}

1447

1580

errno = old_errno;

1448

1581

return ret_errno;

1449

1582

}

1450

1583

1451

1584

/* Set effective and real user ID to 0. Return errno. */

1585

__attribute__((warn_unused_result))

1452

1586

error_t raise_privileges_permanently(void){

1453

1587

error_t old_errno = errno;

1454

1588

error_t ret_errno = raise_privileges();

1458

1592

}

1459

1593

if(setuid(0) == -1){

1460

1594

ret_errno = errno;

1461

perror_plus("seteuid");

1462

1595

}

1463

1596

errno = old_errno;

1464

1597

return ret_errno;

1465

1598

}

1466

1599

1467

1600

/* Set effective user ID to unprivileged saved user ID */

1601

__attribute__((warn_unused_result))

1468

1602

error_t lower_privileges(void){

1469

1603

error_t old_errno = errno;

1470

1604

error_t ret_errno = 0;

1471

1605

if(seteuid(uid) == -1){

1472

1606

ret_errno = errno;

1473

perror_plus("seteuid");

1474

1607

}

1475

1608

errno = old_errno;

1476

1609

return ret_errno;

1477

1610

}

1478

1611

1479

1612

/* Lower privileges permanently */

1613

__attribute__((warn_unused_result))

1480

1614

error_t lower_privileges_permanently(void){

1481

1615

error_t old_errno = errno;

1482

1616

error_t ret_errno = 0;

1483

1617

if(setuid(uid) == -1){

1484

1618

ret_errno = errno;

1485

perror_plus("setuid");

1486

1619

}

1487

1620

errno = old_errno;

1488

1621

return ret_errno;

1489

1622

}

1490

1623

1491

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

1624

__attribute__((nonnull))

1625

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

1492

1626

const float delay){

1493

struct dirent **direntries;

1494

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1495

alphasort);

1627

struct dirent **direntries = NULL;

1628

if(hookdir_fd == -1){

1629

hookdir_fd = open(hookdir, O_RDONLY);

1630

if(hookdir_fd == -1){

1631

if(errno == ENOENT){

1632

if(debug){

1633

fprintf_plus(stderr, "Network hook directory \"%s\" not"

1634

" found\n", hookdir);

1635

}

1636

} else {

1637

perror_plus("open");

1638

}

1639

return;

1640

}

1641

}

1642

#ifdef __GLIBC__

1643

#if __GLIBC_PREREQ(2, 15)

1644

int numhooks = scandirat(hookdir_fd, ".", &direntries,

1645

runnable_hook, alphasort);

1646

#else /* not __GLIBC_PREREQ(2, 15) */

1647

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1648

alphasort);

1649

#endif /* not __GLIBC_PREREQ(2, 15) */

1650

#else /* not __GLIBC__ */

1651

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1652

alphasort);

1653

#endif /* not __GLIBC__ */

1496

1654

if(numhooks == -1){

1497

if(errno == ENOENT){

1498

if(debug){

1499

fprintf_plus(stderr, "Network hook directory \"%s\" not"

1500

" found\n", hookdir);

1501

}

1502

} else {

1503

perror_plus("scandir");

1655

perror_plus("scandir");

1656

return;

1657

}

1658

struct dirent *direntry;

1659

int ret;

1660

int devnull = open("/dev/null", O_RDONLY);

1661

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

1662

direntry = direntries[i];

1663

if(debug){

1664

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1665

direntry->d_name);

1504

1666

}

1505

} else {

1506

struct dirent *direntry;

1507

int ret;

1508

int devnull = open("/dev/null", O_RDONLY);

1509

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

1510

direntry = direntries[i];

1511

char *fullname = NULL;

1512

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1513

if(ret < 0){

1667

pid_t hook_pid = fork();

1668

if(hook_pid == 0){

1669

/* Child */

1670

/* Raise privileges */

1671

errno = raise_privileges_permanently();

1672

if(errno != 0){

1673

perror_plus("Failed to raise privileges");

1674

_exit(EX_NOPERM);

1675

}

1676

/* Set group */

1677

errno = 0;

1678

ret = setgid(0);

1679

if(ret == -1){

1680

perror_plus("setgid");

1681

_exit(EX_NOPERM);

1682

}

1683

/* Reset supplementary groups */

1684

errno = 0;

1685

ret = setgroups(0, NULL);

1686

if(ret == -1){

1687

perror_plus("setgroups");

1688

_exit(EX_NOPERM);

1689

}

1690

ret = dup2(devnull, STDIN_FILENO);

1691

if(ret == -1){

1692

perror_plus("dup2(devnull, STDIN_FILENO)");

1693

_exit(EX_OSERR);

1694

}

1695

ret = close(devnull);

1696

if(ret == -1){

1697

perror_plus("close");

1698

_exit(EX_OSERR);

1699

}

1700

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1701

if(ret == -1){

1702

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

1703

_exit(EX_OSERR);

1704

}

1705

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1706

if(ret == -1){

1707

perror_plus("setenv");

1708

_exit(EX_OSERR);

1709

}

1710

ret = setenv("DEVICE", interface, 1);

1711

if(ret == -1){

1712

perror_plus("setenv");

1713

_exit(EX_OSERR);

1714

}

1715

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

1716

if(ret == -1){

1717

perror_plus("setenv");

1718

_exit(EX_OSERR);

1719

}

1720

ret = setenv("MODE", mode, 1);

1721

if(ret == -1){

1722

perror_plus("setenv");

1723

_exit(EX_OSERR);

1724

}

1725

char *delaystring;

1726

ret = asprintf(&delaystring, "%f", (double)delay);

1727

if(ret == -1){

1514

1728

perror_plus("asprintf");

1515

continue;

1516

}

1517

if(debug){

1518

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1519

direntry->d_name);

1520

}

1521

pid_t hook_pid = fork();

1522

if(hook_pid == 0){

1523

/* Child */

1524

/* Raise privileges */

1525

raise_privileges_permanently();

1526

/* Set group */

1527

errno = 0;

1528

ret = setgid(0);

1529

if(ret == -1){

1530

perror_plus("setgid");

1531

}

1532

/* Reset supplementary groups */

1533

errno = 0;

1534

ret = setgroups(0, NULL);

1535

if(ret == -1){

1536

perror_plus("setgroups");

1537

}

1538

dup2(devnull, STDIN_FILENO);

1539

close(devnull);

1540

dup2(STDERR_FILENO, STDOUT_FILENO);

1541

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1542

if(ret == -1){

1543

perror_plus("setenv");

1544

_exit(EX_OSERR);

1545

}

1546

ret = setenv("DEVICE", interface, 1);

1547

if(ret == -1){

1548

perror_plus("setenv");

1549

_exit(EX_OSERR);

1550

}

1551

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

1552

if(ret == -1){

1553

perror_plus("setenv");

1554

_exit(EX_OSERR);

1555

}

1556

ret = setenv("MODE", mode, 1);

1557

if(ret == -1){

1558

perror_plus("setenv");

1559

_exit(EX_OSERR);

1560

}

1561

char *delaystring;

1562

ret = asprintf(&delaystring, "%f", delay);

1563

if(ret == -1){

1564

perror_plus("asprintf");

1565

_exit(EX_OSERR);

1566

}

1567

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

1568

if(ret == -1){

1569

free(delaystring);

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1729

_exit(EX_OSERR);

1730

}

1731

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

1732

if(ret == -1){

1573

1733

free(delaystring);

1574

if(connect_to != NULL){

1575

ret = setenv("CONNECT", connect_to, 1);

1576

if(ret == -1){

1577

perror_plus("setenv");

1578

_exit(EX_OSERR);

1579

}

1580

}

1581

if(execl(fullname, direntry->d_name, mode, NULL) == -1){

1582

perror_plus("execl");

1583

_exit(EXIT_FAILURE);

1584

}

1734

perror_plus("setenv");

1735

_exit(EX_OSERR);

1736

}

1737

free(delaystring);

1738

if(connect_to != NULL){

1739

ret = setenv("CONNECT", connect_to, 1);

1740

if(ret == -1){

1741

perror_plus("setenv");

1742

_exit(EX_OSERR);

1743

}

1744

}

1745

int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);

1746

if(hook_fd == -1){

1747

perror_plus("openat");

1748

_exit(EXIT_FAILURE);

1749

}

1750

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

1751

perror_plus("close");

1752

_exit(EXIT_FAILURE);

1753

}

1754

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

1755

environ) == -1){

1756

perror_plus("fexecve");

1757

_exit(EXIT_FAILURE);

1758

}

1759

} else {

1760

if(hook_pid == -1){

1761

perror_plus("fork");

1762

free(direntry);

1763

continue;

1764

}

1765

int status;

1766

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1767

perror_plus("waitpid");

1768

free(direntry);

1769

continue;

1770

}

1771

if(WIFEXITED(status)){

1772

if(WEXITSTATUS(status) != 0){

1773

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1774

" with status %d\n", direntry->d_name,

1775

WEXITSTATUS(status));

1776

free(direntry);

1777

continue;

1778

}

1779

} else if(WIFSIGNALED(status)){

1780

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1781

" signal %d\n", direntry->d_name,

1782

WTERMSIG(status));

1783

free(direntry);

1784

continue;

1585

1785

} else {

1586

int status;

1587

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1588

perror_plus("waitpid");

1589

free(fullname);

1590

continue;

1591

}

1592

if(WIFEXITED(status)){

1593

if(WEXITSTATUS(status) != 0){

1594

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1595

" with status %d\n", direntry->d_name,

1596

WEXITSTATUS(status));

1597

free(fullname);

1598

continue;

1599

}

1600

} else if(WIFSIGNALED(status)){

1601

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1602

" signal %d\n", direntry->d_name,

1603

WTERMSIG(status));

1604

free(fullname);

1605

continue;

1606

} else {

1607

fprintf_plus(stderr, "Warning: network hook \"%s\""

1608

" crashed\n", direntry->d_name);

1609

free(fullname);

1610

continue;

1611

}

1612

}

1613

free(fullname);

1614

if(debug){

1615

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1616

direntry->d_name);

1617

}

1618

}

1619

close(devnull);

1620

}

1621

return true;

1786

fprintf_plus(stderr, "Warning: network hook \"%s\""

1787

" crashed\n", direntry->d_name);

1788

free(direntry);

1789

continue;

1790

}

1791

}

1792

if(debug){

1793

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1794

direntry->d_name);

1795

}

1796

free(direntry);

1797

}

1798

free(direntries);

1799

if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){

1800

perror_plus("close");

1801

} else {

1802

hookdir_fd = -1;

1803

}

1804

close(devnull);

1622

1805

}

1623

1806

1807

__attribute__((nonnull, warn_unused_result))

1624

1808

error_t bring_up_interface(const char *const interface,

1625

1809

const float delay){

1626

int sd = -1;

1627

1810

error_t old_errno = errno;

1628

error_t ret_errno = 0;

1629

int ret, ret_setflags;

1811

int ret;

1630

1812

struct ifreq network;

1631

1813

unsigned int if_index = if_nametoindex(interface);

1632

1814

if(if_index == 0){

1641

1823

}

1642

1824

1643

1825

if(not interface_is_up(interface)){

1644

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

1826

error_t ret_errno = 0, ioctl_errno = 0;

1827

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

1645

1828

ret_errno = errno;

1646

1829

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

1647

1830

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

1831

errno = old_errno;

1648

1832

return ret_errno;

1649

1833

}

1650

network.ifr_flags |= IFF_UP;

1834

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

1651

1835

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

1836

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

1837

if(sd == -1){

1654

1838

ret_errno = errno;

1655

1839

perror_plus("socket");

1656

1840

errno = old_errno;

1657

1841

return ret_errno;

1658

1842

}

1659

1843

1660

1844

if(quit_now){

1661

close(sd);

1845

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

1846

if(ret == -1){

1847

perror_plus("close");

1848

}

1662

1849

errno = old_errno;

1663

1850

return EINTR;

1664

1851

}

1668

1855

interface);

1669

1856

}

1670

1857

1671

/* Raise priviliges */

1672

raise_privileges();

1858

/* Raise privileges */

1859

ret_errno = raise_privileges();

1860

if(ret_errno != 0){

1861

errno = ret_errno;

1862

perror_plus("Failed to raise privileges");

1863

}

1673

1864

1674

1865

#ifdef __linux__

1675

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1676

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

1677

int ret_linux = klogctl(8, NULL, 5);

1678

bool restore_loglevel = true;

1679

if(ret_linux == -1){

1680

restore_loglevel = false;

1681

perror_plus("klogctl");

1866

int ret_linux;

1867

bool restore_loglevel = false;

1868

if(ret_errno == 0){

1869

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1870

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

1871

ret_linux = klogctl(8, NULL, 5);

1872

if(ret_linux == -1){

1873

perror_plus("klogctl");

1874

} else {

1875

restore_loglevel = true;

1876

}

1682

1877

}

1683

1878

#endif /* __linux__ */

1684

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

1685

ret_errno = errno;

1879

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

1880

ioctl_errno = errno;

1686

1881

#ifdef __linux__

1687

1882

if(restore_loglevel){

1688

1883

ret_linux = klogctl(7, NULL, 0);

1692

1887

}

1693

1888

#endif /* __linux__ */

1694

1889

1695

/* Lower privileges */

1696

lower_privileges();

1890

/* If raise_privileges() succeeded above */

1891

if(ret_errno == 0){

1892

/* Lower privileges */

1893

ret_errno = lower_privileges();

1894

if(ret_errno != 0){

1895

errno = ret_errno;

1896

perror_plus("Failed to lower privileges");

1897

}

1898

}

1697

1899

1698

1900

/* Close the socket */

1699

1901

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

1702

1904

}

1703

1905

1704

1906

if(ret_setflags == -1){

1705

errno = ret_errno;

1907

errno = ioctl_errno;

1706

1908

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1707

1909

errno = old_errno;

1708

return ret_errno;

1910

return ioctl_errno;

1709

1911

}

1710

1912

} else if(debug){

1711

1913

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

1729

1931

return 0;

1730

1932

}

1731

1933

1934

__attribute__((nonnull, warn_unused_result))

1732

1935

error_t take_down_interface(const char *const interface){

1733

1936

error_t old_errno = errno;

1734

1937

struct ifreq network;

1739

1942

return ENXIO;

1740

1943

}

1741

1944

if(interface_is_up(interface)){

1742

error_t ret_errno = 0;

1945

error_t ret_errno = 0, ioctl_errno = 0;

1743

1946

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

1744

1947

ret_errno = errno;

1745

1948

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

1746

1949

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

1950

errno = old_errno;

1747

1951

return ret_errno;

1748

1952

}

1749

1953

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

1750

1954

1751

1955

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

1752

if(sd < 0){

1956

if(sd == -1){

1753

1957

ret_errno = errno;

1754

1958

perror_plus("socket");

1755

1959

errno = old_errno;

1761

1965

interface);

1762

1966

}

1763

1967

1764

/* Raise priviliges */

1765

raise_privileges();

1968

/* Raise privileges */

1969

ret_errno = raise_privileges();

1970

if(ret_errno != 0){

1971

errno = ret_errno;

1972

perror_plus("Failed to raise privileges");

1973

}

1766

1974

1767

1975

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

1768

ret_errno = errno;

1976

ioctl_errno = errno;

1769

1977

1770

/* Lower privileges */

1771

lower_privileges();

1978

/* If raise_privileges() succeeded above */

1979

if(ret_errno == 0){

1980

/* Lower privileges */

1981

ret_errno = lower_privileges();

1982

if(ret_errno != 0){

1983

errno = ret_errno;

1984

perror_plus("Failed to lower privileges");

1985

}

1986

}

1772

1987

1773

1988

/* Close the socket */

1774

1989

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

1777

1992

}

1778

1993

1779

1994

if(ret_setflags == -1){

1780

errno = ret_errno;

1995

errno = ioctl_errno;

1781

1996

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1782

1997

errno = old_errno;

1783

return ret_errno;

1998

return ioctl_errno;

1784

1999

}

1785

2000

} else if(debug){

1786

2001

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

1792

2007

}

1793

2008

1794

2009

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

1795

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

2010

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

1796

2011

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

1797

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

2012

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

1798

2013

.interfaces = NULL, .interfaces_size = 0 };

1799

2014

AvahiSServiceBrowser *sb = NULL;

1800

2015

error_t ret_errno;

1804

2019

int exitcode = EXIT_SUCCESS;

1805

2020

char *interfaces_to_take_down = NULL;

1806

2021

size_t interfaces_to_take_down_size = 0;

1807

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

1808

bool tempdir_created = false;

2022

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

2023

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

2024

char *tempdir = NULL;

1809

2025

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1810

2026

const char *seckey = PATHDIR "/" SECKEY;

1811

2027

const char *pubkey = PATHDIR "/" PUBKEY;

1993

2209

/* Work around Debian bug #633582:

1994

2210

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

1995

2211

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2212

/* Re-raise privileges */

2213

ret_errno = raise_privileges();

2214

if(ret_errno != 0){

2215

errno = ret_errno;

2216

perror_plus("Failed to raise privileges");

2217

} else {

1998

2218

struct stat st;

1999

2219

2000

2220

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

2040

2260

}

2041

2261

2042

2262

/* Lower privileges */

2043

lower_privileges();

2263

ret_errno = lower_privileges();

2264

if(ret_errno != 0){

2265

errno = ret_errno;

2266

perror_plus("Failed to lower privileges");

2267

}

2044

2268

}

2045

2269

}

2046

2270

2072

2296

memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);

2073

2297

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

2074

2298

}

2075

if(not run_network_hooks("start", interfaces_hooks != NULL ?

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2299

run_network_hooks("start", interfaces_hooks != NULL ?

2300

interfaces_hooks : "", delay);

2079

2301

}

2080

2302

2081

2303

if(not debug){

2159

2381

2160

2382

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

2161

2383

if(mc.interfaces == NULL){

2162

struct dirent **direntries;

2384

struct dirent **direntries = NULL;

2163

2385

/* Look for any good interfaces */

2164

2386

ret = scandir(sys_class_net, &direntries, good_interface,

2165

2387

alphasort);

2171

2393

if(ret_errno != 0){

2172

2394

errno = ret_errno;

2173

2395

perror_plus("argz_add");

2396

free(direntries[i]);

2174

2397

continue;

2175

2398

}

2176

2399

if(debug){

2177

2400

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

2178

2401

direntries[i]->d_name);

2179

2402

}

2403

free(direntries[i]);

2180

2404

}

2181

2405

free(direntries);

2182

2406

} else {

2183

free(direntries);

2407

if(ret == 0){

2408

free(direntries);

2409

}

2184

2410

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

2185

2411

exitcode = EXIT_FAILURE;

2186

2412

goto end;

2209

2435

break;

2210

2436

}

2211

2437

bool interface_was_up = interface_is_up(interface);

2212

ret = bring_up_interface(interface, delay);

2438

errno = bring_up_interface(interface, delay);

2213

2439

if(not interface_was_up){

2214

if(ret != 0){

2215

errno = ret;

2440

if(errno != 0){

2216

2441

perror_plus("Failed to bring up interface");

2217

2442

} else {

2218

ret_errno = argz_add(&interfaces_to_take_down,

2219

&interfaces_to_take_down_size,

2220

interface);

2221

if(ret_errno != 0){

2222

errno = ret_errno;

2443

errno = argz_add(&interfaces_to_take_down,

2444

&interfaces_to_take_down_size,

2445

interface);

2446

if(errno != 0){

2223

2447

perror_plus("argz_add");

2224

2448

}

2225

2449

}

2256

2480

goto end;

2257

2481

}

2258

2482

2259

if(mkdtemp(tempdir) == NULL){

2483

/* Try /run/tmp before /tmp */

2484

tempdir = mkdtemp(run_tempdir);

2485

if(tempdir == NULL and errno == ENOENT){

2486

if(debug){

2487

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

2488

run_tempdir, old_tempdir);

2489

}

2490

tempdir = mkdtemp(old_tempdir);

2491

}

2492

if(tempdir == NULL){

2260

2493

perror_plus("mkdtemp");

2261

2494

goto end;

2262

2495

}

2263

tempdir_created = true;

2264

2496

2265

2497

if(quit_now){

2266

2498

goto end;

2341

2573

sleep((unsigned int)retry_interval);

2342

2574

}

2343

2575

2344

if (not quit_now){

2576

if(not quit_now){

2345

2577

exitcode = EXIT_SUCCESS;

2346

2578

}

2347

2579

2402

2634

if(debug){

2403

2635

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

2404

2636

}

2405

2637

2406

2638

ret = avahi_loop_with_timeout(simple_poll,

2407

2639

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

2408

2640

if(debug){

2444

2676

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

2445

2677

while(mc.current_server != NULL){

2446

2678

server *next = mc.current_server->next;

2679

#ifdef __GNUC__

2680

#pragma GCC diagnostic push

2681

#pragma GCC diagnostic ignored "-Wcast-qual"

2682

#endif

2683

free((char *)(mc.current_server->ip));

2684

#ifdef __GNUC__

2685

#pragma GCC diagnostic pop

2686

#endif

2447

2687

free(mc.current_server);

2448

2688

mc.current_server = next;

2449

2689

}

2450

2690

}

2451

2691

2452

/* Re-raise priviliges */

2692

/* Re-raise privileges */

2453

2693

{

2454

raise_privileges();

2455

2456

/* Run network hooks */

2457

run_network_hooks("stop", interfaces_hooks != NULL ?

2458

interfaces_hooks : "", delay);

2459

2460

/* Take down the network interfaces which were brought up */

2461

{

2462

char *interface = NULL;

2463

while((interface=argz_next(interfaces_to_take_down,

2464

interfaces_to_take_down_size,

2465

interface))){

2466

ret_errno = take_down_interface(interface);

2467

if(ret_errno != 0){

2468

errno = ret_errno;

2469

perror_plus("Failed to take down interface");

2470

}

2471

}

2472

if(debug and (interfaces_to_take_down == NULL)){

2473

fprintf_plus(stderr, "No interfaces needed to be taken"

2474

" down\n");

2475

}

2476

}

2477

2478

lower_privileges_permanently();

2694

ret_errno = raise_privileges();

2695

if(ret_errno != 0){

2696

errno = ret_errno;

2697

perror_plus("Failed to raise privileges");

2698

} else {

2699

2700

/* Run network hooks */

2701

run_network_hooks("stop", interfaces_hooks != NULL ?

2702

interfaces_hooks : "", delay);

2703

2704

/* Take down the network interfaces which were brought up */

2705

{

2706

char *interface = NULL;

2707

while((interface=argz_next(interfaces_to_take_down,

2708

interfaces_to_take_down_size,

2709

interface))){

2710

ret_errno = take_down_interface(interface);

2711

if(ret_errno != 0){

2712

errno = ret_errno;

2713

perror_plus("Failed to take down interface");

2714

}

2715

}

2716

if(debug and (interfaces_to_take_down == NULL)){

2717

fprintf_plus(stderr, "No interfaces needed to be taken"

2718

" down\n");

2719

}

2720

}

2721

}

2722

2723

ret_errno = lower_privileges_permanently();

2724

if(ret_errno != 0){

2725

errno = ret_errno;

2726

perror_plus("Failed to lower privileges permanently");

2727

}

2479

2728

}

2480

2729

2481

2730

free(interfaces_to_take_down);

2482

2731

free(interfaces_hooks);

2483

2732

2484

2733

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

2485

if(tempdir_created){

2734

if(tempdir != NULL){

2486

2735

struct dirent **direntries = NULL;

2487

struct dirent *direntry = NULL;

2488

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

2489

alphasort);

2490

if (numentries > 0){

2491

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

2492

direntry = direntries[i];

2493

char *fullname = NULL;

2494

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

2495

direntry->d_name);

2496

if(ret < 0){

2497

perror_plus("asprintf");

2498

continue;

2499

}

2500

ret = remove(fullname);

2501

if(ret == -1){

2502

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2503

strerror(errno));

2504

}

2505

free(fullname);

2736

int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |

2737

O_NOFOLLOW));

2738

if(tempdir_fd == -1){

2739

perror_plus("open");

2740

} else {

2741

#ifdef __GLIBC__

2742

#if __GLIBC_PREREQ(2, 15)

2743

int numentries = scandirat(tempdir_fd, ".", &direntries,

2744

notdotentries, alphasort);

2745

#else /* not __GLIBC_PREREQ(2, 15) */

2746

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

2747

alphasort);

2748

#endif /* not __GLIBC_PREREQ(2, 15) */

2749

#else /* not __GLIBC__ */

2750

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

2751

alphasort);

2752

#endif /* not __GLIBC__ */

2753

if(numentries >= 0){

2754

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

2755

ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);

2756

if(ret == -1){

2757

fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"

2758

" \"%s\", 0): %s\n", tempdir,

2759

direntries[i]->d_name, strerror(errno));

2760

}

2761

free(direntries[i]);

2762

}

2763

2764

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

2765

free(direntries);

2766

if(numentries == -1){

2767

perror_plus("scandir");

2768

}

2769

ret = rmdir(tempdir);

2770

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

2771

perror_plus("rmdir");

2772

}

2506

2773

}

2507

}

2508

2509

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

2510

free(direntries);

2511

if (numentries == -1){

2512

perror_plus("scandir");

2513

}

2514

ret = rmdir(tempdir);

2515

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

2516

perror_plus("rmdir");

2774

TEMP_FAILURE_RETRY(close(tempdir_fd));

2517

2775

}

2518

2776

}

2519

2777