/mandos/release : revision 312

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

183

perror(print_text);

184

}

185

186

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

186

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

187

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

188

va_list ap;

189

va_start (ap, format);

198

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

199

* "buffer_length" is how much is already used.

200

*/

201

__attribute__((nonnull, warn_unused_result))

201

202

size_t incbuffer(char **buffer, size_t buffer_length,

202

203

size_t buffer_capacity){

203

204

if(buffer_length + BUFFER_SIZE > buffer_capacity){

216

217

}

217

218

219

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

220

__attribute__((nonnull, warn_unused_result))

219

221

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

220

222

int af, server **current_server){

221

223

int ret;

242

244

new_server->next = new_server;

243

245

new_server->prev = new_server;

244

246

*current_server = new_server;

245

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

246

247

} else {

248

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

247

249

new_server->next = *current_server;

248

250

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

249

251

new_server->prev->next = new_server;

255

257

/*

256

258

* Initialize GPGME.

257

259

*/

258

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

259

const char *tempdir, mandos_context *mc){

260

__attribute__((nonnull, warn_unused_result))

261

static bool init_gpgme(const char * const seckey,

262

const char * const pubkey,

263

const char * const tempdir,

264

mandos_context *mc){

260

265

gpgme_error_t rc;

261

266

gpgme_engine_info_t engine_info;

262

267

263

268

/*

264

269

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

265

270

*/

266

bool import_key(const char *filename){

271

bool import_key(const char * const filename){

267

272

int ret;

268

273

int fd;

269

274

gpgme_data_t pgp_data;

350

355

* Decrypt OpenPGP data.

351

356

* Returns -1 on error

352

357

*/

358

__attribute__((nonnull, warn_unused_result))

353

359

static ssize_t pgp_packet_decrypt(const char *cryptotext,

354

360

size_t crypto_size,

355

361

char **plaintext,

475

481

return plaintext_length;

476

482

}

477

483

478

static const char * safer_gnutls_strerror(int value){

484

__attribute__((warn_unused_result))

485

static const char *safer_gnutls_strerror(int value){

479

486

const char *ret = gnutls_strerror(value);

480

487

if(ret == NULL)

481

488

ret = "(unknown)";

483

490

}

484

491

485

492

/* GnuTLS log function callback */

493

__attribute__((nonnull))

486

494

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

487

495

const char* string){

488

496

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

489

497

}

490

498

499

__attribute__((nonnull, warn_unused_result))

491

500

static int init_gnutls_global(const char *pubkeyfilename,

492

501

const char *seckeyfilename,

493

502

mandos_context *mc){

567

576

return -1;

568

577

}

569

578

579

__attribute__((nonnull, warn_unused_result))

570

580

static int init_gnutls_session(gnutls_session_t *session,

571

581

mandos_context *mc){

572

582

int ret;

629

639

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

630

640

631

641

/* Called when a Mandos server is found */

642

__attribute__((nonnull, warn_unused_result))

632

643

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

633

644

AvahiIfIndex if_index,

634

645

int af, mandos_context *mc){

740

751

goto mandos_end;

741

752

}

742

753

if(af == AF_INET6){

743

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

754

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

744

755

if(IN6_IS_ADDR_LINKLOCAL

745

756

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

746

757

if(if_index == AVAHI_IF_UNSPEC){

1030

1041

return retval;

1031

1042

}

1032

1043

1044

__attribute__((nonnull))

1033

1045

static void resolve_callback(AvahiSServiceResolver *r,

1034

1046

AvahiIfIndex interface,

1035

1047

AvahiProtocol proto,

1043

1055

AVAHI_GCC_UNUSED AvahiStringList *txt,

1044

1056

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1045

1057

flags,

1046

void* mc){

1058

void *mc){

1047

1059

if(r == NULL){

1048

1060

return;

1049

1061

}

1102

1114

const char *domain,

1103

1115

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1104

1116

flags,

1105

void* mc){

1117

void *mc){

1106

1118

if(b == NULL){

1107

1119

return;

1108

1120

}

1168

1180

errno = old_errno;

1169

1181

}

1170

1182

1183

__attribute__((nonnull, warn_unused_result))

1171

1184

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

1172

1185

int ret;

1173

1186

error_t ret_errno;

1192

1205

return true;

1193

1206

}

1194

1207

1208

__attribute__((nonnull, warn_unused_result))

1195

1209

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

1196

1210

1197

1211

/* Reject the loopback device */

1239

1253

* corresponds to an acceptable network device.

1240

1254

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

1241

1255

*/

1256

__attribute__((nonnull, warn_unused_result))

1242

1257

int good_interface(const struct dirent *if_entry){

1243

1258

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

1244

1259

return 0;

1262

1277

/*

1263

1278

* This function determines if a network interface is up.

1264

1279

*/

1280

__attribute__((nonnull, warn_unused_result))

1265

1281

bool interface_is_up(const char *interface){

1266

1282

struct ifreq ifr;

1267

1283

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

1278

1294

/*

1279

1295

* This function determines if a network interface is running

1280

1296

*/

1297

__attribute__((nonnull, warn_unused_result))

1281

1298

bool interface_is_running(const char *interface){

1282

1299

struct ifreq ifr;

1283

1300

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

1291

1308

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

1292

1309

}

1293

1310

1311

__attribute__((nonnull, pure, warn_unused_result))

1294

1312

int notdotentries(const struct dirent *direntry){

1295

1313

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

1296

1314

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

1303

1321

}

1304

1322

1305

1323

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

1324

__attribute__((nonnull, warn_unused_result))

1306

1325

int runnable_hook(const struct dirent *direntry){

1307

1326

int ret;

1308

1327

size_t sret;

1363

1382

return 1;

1364

1383

}

1365

1384

1385

__attribute__((nonnull, warn_unused_result))

1366

1386

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1367

1387

mandos_context *mc){

1368

1388

int ret;

1437

1457

}

1438

1458

1439

1459

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

1460

__attribute__((warn_unused_result))

1440

1461

error_t raise_privileges(void){

1441

1462

error_t old_errno = errno;

1442

1463

error_t ret_errno = 0;

1449

1470

}

1450

1471

1451

1472

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

1473

__attribute__((warn_unused_result))

1452

1474

error_t raise_privileges_permanently(void){

1453

1475

error_t old_errno = errno;

1454

1476

error_t ret_errno = raise_privileges();

1465

1487

}

1466

1488

1467

1489

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

1490

__attribute__((warn_unused_result))

1468

1491

error_t lower_privileges(void){

1469

1492

error_t old_errno = errno;

1470

1493

error_t ret_errno = 0;

1477

1500

}

1478

1501

1479

1502

/* Lower privileges permanently */

1503

__attribute__((warn_unused_result))

1480

1504

error_t lower_privileges_permanently(void){

1481

1505

error_t old_errno = errno;

1482

1506

error_t ret_errno = 0;

1488

1512

return ret_errno;

1489

1513

}

1490

1514

1491

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

1515

__attribute__((nonnull))

1516

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

1492

1517

const float delay){

1493

1518

struct dirent **direntries;

1494

1519

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

1522

1547

if(hook_pid == 0){

1523

1548

/* Child */

1524

1549

/* Raise privileges */

1525

raise_privileges_permanently();

1550

if(raise_privileges_permanently() != 0){

1551

perror_plus("Failed to raise privileges");

1552

_exit(EX_NOPERM);

1553

}

1526

1554

/* Set group */

1527

1555

errno = 0;

1528

1556

ret = setgid(0);

1529

1557

if(ret == -1){

1530

1558

perror_plus("setgid");

1559

_exit(EX_NOPERM);

1531

1560

}

1532

1561

/* Reset supplementary groups */

1533

1562

errno = 0;

1534

1563

ret = setgroups(0, NULL);

1535

1564

if(ret == -1){

1536

1565

perror_plus("setgroups");

1537

}

1538

dup2(devnull, STDIN_FILENO);

1539

close(devnull);

1540

dup2(STDERR_FILENO, STDOUT_FILENO);

1566

_exit(EX_NOPERM);

1567

}

1568

ret = dup2(devnull, STDIN_FILENO);

1569

if(ret == -1){

1570

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

1571

_exit(EX_OSERR);

1572

}

1573

ret = close(devnull);

1574

if(ret == -1){

1575

perror_plus("close");

1576

_exit(EX_OSERR);

1577

}

1578

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1579

if(ret == -1){

1580

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

1581

_exit(EX_OSERR);

1582

}

1541

1583

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

1542

1584

if(ret == -1){

1543

1585

perror_plus("setenv");

1559

1601

_exit(EX_OSERR);

1560

1602

}

1561

1603

char *delaystring;

1562

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

1604

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

1563

1605

if(ret == -1){

1564

1606

perror_plus("asprintf");

1565

1607

_exit(EX_OSERR);

1618

1660

}

1619

1661

close(devnull);

1620

1662

}

1621

return true;

1622

1663

}

1623

1664

1665

__attribute__((nonnull, warn_unused_result))

1624

1666

error_t bring_up_interface(const char *const interface,

1625

1667

const float delay){

1626

int sd = -1;

1627

1668

error_t old_errno = errno;

1628

error_t ret_errno = 0;

1629

int ret, ret_setflags;

1669

int ret;

1630

1670

struct ifreq network;

1631

1671

unsigned int if_index = if_nametoindex(interface);

1632

1672

if(if_index == 0){

1641

1681

}

1642

1682

1643

1683

if(not interface_is_up(interface)){

1644

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

1684

error_t ret_errno = 0, ioctl_errno = 0;

1685

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

1645

1686

ret_errno = errno;

1646

1687

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

1647

1688

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

1689

errno = old_errno;

1648

1690

return ret_errno;

1649

1691

}

1650

network.ifr_flags |= IFF_UP;

1692

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

1651

1693

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

1694

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

1695

if(sd == -1){

1654

1696

ret_errno = errno;

1655

1697

perror_plus("socket");

1656

1698

errno = old_errno;

1657

1699

return ret_errno;

1658

1700

}

1659

1701

1660

1702

if(quit_now){

1661

close(sd);

1703

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

1704

if(ret == -1){

1705

perror_plus("close");

1706

}

1662

1707

errno = old_errno;

1663

1708

return EINTR;

1664

1709

}

1668

1713

interface);

1669

1714

}

1670

1715

1671

/* Raise priviliges */

1672

raise_privileges();

1716

/* Raise privileges */

1717

ret_errno = raise_privileges();

1718

if(ret_errno != 0){

1719

perror_plus("Failed to raise privileges");

1720

}

1673

1721

1674

1722

#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");

1723

int ret_linux;

1724

bool restore_loglevel = false;

1725

if(ret_errno == 0){

1726

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1727

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

1728

ret_linux = klogctl(8, NULL, 5);

1729

if(ret_linux == -1){

1730

perror_plus("klogctl");

1731

} else {

1732

restore_loglevel = true;

1733

}

1682

1734

}

1683

1735

#endif /* __linux__ */

1684

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

1685

ret_errno = errno;

1736

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

1737

ioctl_errno = errno;

1686

1738

#ifdef __linux__

1687

1739

if(restore_loglevel){

1688

1740

ret_linux = klogctl(7, NULL, 0);

1692

1744

}

1693

1745

#endif /* __linux__ */

1694

1746

1695

/* Lower privileges */

1696

lower_privileges();

1747

/* If raise_privileges() succeeded above */

1748

if(ret_errno == 0){

1749

/* Lower privileges */

1750

ret_errno = lower_privileges();

1751

if(ret_errno != 0){

1752

errno = ret_errno;

1753

perror_plus("Failed to lower privileges");

1754

}

1755

}

1697

1756

1698

1757

/* Close the socket */

1699

1758

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

1702

1761

}

1703

1762

1704

1763

if(ret_setflags == -1){

1705

errno = ret_errno;

1764

errno = ioctl_errno;

1706

1765

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1707

1766

errno = old_errno;

1708

return ret_errno;

1767

return ioctl_errno;

1709

1768

}

1710

1769

} else if(debug){

1711

1770

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

1729

1788

return 0;

1730

1789

}

1731

1790

1791

__attribute__((nonnull, warn_unused_result))

1732

1792

error_t take_down_interface(const char *const interface){

1733

1793

error_t old_errno = errno;

1734

1794

struct ifreq network;

1739

1799

return ENXIO;

1740

1800

}

1741

1801

if(interface_is_up(interface)){

1742

error_t ret_errno = 0;

1802

error_t ret_errno = 0, ioctl_errno = 0;

1743

1803

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

1744

1804

ret_errno = errno;

1745

1805

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

1746

1806

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

1807

errno = old_errno;

1747

1808

return ret_errno;

1748

1809

}

1749

1810

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

1750

1811

1751

1812

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

1752

if(sd < 0){

1813

if(sd == -1){

1753

1814

ret_errno = errno;

1754

1815

perror_plus("socket");

1755

1816

errno = old_errno;

1761

1822

interface);

1762

1823

}

1763

1824

1764

/* Raise priviliges */

1765

raise_privileges();

1825

/* Raise privileges */

1826

ret_errno = raise_privileges();

1827

if(ret_errno != 0){

1828

perror_plus("Failed to raise privileges");

1829

}

1766

1830

1767

1831

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

1768

ret_errno = errno;

1832

ioctl_errno = errno;

1769

1833

1770

/* Lower privileges */

1771

lower_privileges();

1834

/* If raise_privileges() succeeded above */

1835

if(ret_errno == 0){

1836

/* Lower privileges */

1837

ret_errno = lower_privileges();

1838

if(ret_errno != 0){

1839

errno = ret_errno;

1840

perror_plus("Failed to lower privileges");

1841

}

1842

}

1772

1843

1773

1844

/* Close the socket */

1774

1845

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

1777

1848

}

1778

1849

1779

1850

if(ret_setflags == -1){

1780

errno = ret_errno;

1851

errno = ioctl_errno;

1781

1852

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1782

1853

errno = old_errno;

1783

return ret_errno;

1854

return ioctl_errno;

1784

1855

}

1785

1856

} else if(debug){

1786

1857

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

1794

1865

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

1795

1866

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

1796

1867

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

1797

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

1868

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

1798

1869

.interfaces = NULL, .interfaces_size = 0 };

1799

1870

AvahiSServiceBrowser *sb = NULL;

1800

1871

error_t ret_errno;

1804

1875

int exitcode = EXIT_SUCCESS;

1805

1876

char *interfaces_to_take_down = NULL;

1806

1877

size_t interfaces_to_take_down_size = 0;

1807

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

1808

bool tempdir_created = false;

1878

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

1879

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

1880

char *tempdir = NULL;

1809

1881

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1810

1882

const char *seckey = PATHDIR "/" SECKEY;

1811

1883

const char *pubkey = PATHDIR "/" PUBKEY;

1993

2065

/* Work around Debian bug #633582:

1994

2066

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

1995

2067

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2068

/* Re-raise privileges */

2069

ret_errno = raise_privileges();

2070

if(ret_errno != 0){

2071

errno = ret_errno;

2072

perror_plus("Failed to raise privileges");

2073

} else {

1998

2074

struct stat st;

1999

2075

2000

2076

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

2040

2116

}

2041

2117

2042

2118

/* Lower privileges */

2043

lower_privileges();

2119

ret_errno = lower_privileges();

2120

if(ret_errno != 0){

2121

errno = ret_errno;

2122

perror_plus("Failed to lower privileges");

2123

}

2044

2124

}

2045

2125

}

2046

2126

2072

2152

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

2073

2153

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

2074

2154

}

2075

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

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2155

run_network_hooks("start", interfaces_hooks != NULL ?

2156

interfaces_hooks : "", delay);

2079

2157

}

2080

2158

2081

2159

if(not debug){

2209

2287

break;

2210

2288

}

2211

2289

bool interface_was_up = interface_is_up(interface);

2212

ret = bring_up_interface(interface, delay);

2290

errno = bring_up_interface(interface, delay);

2213

2291

if(not interface_was_up){

2214

if(ret != 0){

2215

errno = ret;

2292

if(errno != 0){

2216

2293

perror_plus("Failed to bring up interface");

2217

2294

} 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;

2295

errno = argz_add(&interfaces_to_take_down,

2296

&interfaces_to_take_down_size,

2297

interface);

2298

if(errno != 0){

2223

2299

perror_plus("argz_add");

2224

2300

}

2225

2301

}

2256

2332

goto end;

2257

2333

}

2258

2334

2259

if(mkdtemp(tempdir) == NULL){

2335

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

2336

tempdir = mkdtemp(run_tempdir);

2337

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

2338

if(debug){

2339

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

2340

run_tempdir, old_tempdir);

2341

}

2342

tempdir = mkdtemp(old_tempdir);

2343

}

2344

if(tempdir == NULL){

2260

2345

perror_plus("mkdtemp");

2261

2346

goto end;

2262

2347

}

2263

tempdir_created = true;

2264

2348

2265

2349

if(quit_now){

2266

2350

goto end;

2449

2533

}

2450

2534

}

2451

2535

2452

/* Re-raise priviliges */

2536

/* Re-raise privileges */

2453

2537

{

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();

2538

ret_errno = raise_privileges();

2539

if(ret_errno != 0){

2540

perror_plus("Failed to raise privileges");

2541

} else {

2542

2543

/* Run network hooks */

2544

run_network_hooks("stop", interfaces_hooks != NULL ?

2545

interfaces_hooks : "", delay);

2546

2547

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

2548

{

2549

char *interface = NULL;

2550

while((interface=argz_next(interfaces_to_take_down,

2551

interfaces_to_take_down_size,

2552

interface))){

2553

ret_errno = take_down_interface(interface);

2554

if(ret_errno != 0){

2555

errno = ret_errno;

2556

perror_plus("Failed to take down interface");

2557

}

2558

}

2559

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

2560

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

2561

" down\n");

2562

}

2563

}

2564

}

2565

2566

ret_errno = lower_privileges_permanently();

2567

if(ret_errno != 0){

2568

perror_plus("Failed to lower privileges permanently");

2569

}

2479

2570

}

2480

2571

2481

2572

free(interfaces_to_take_down);

2482

2573

free(interfaces_hooks);

2483

2574

2484

2575

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

2485

if(tempdir_created){

2576

if(tempdir != NULL){

2486

2577

struct dirent **direntries = NULL;

2487

2578

struct dirent *direntry = NULL;

2488

2579

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