/mandos/trunk : revision 742

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(),

55

opendir(), DIR */

56

#include <sys/stat.h> /* open(), S_ISREG */

57

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

58

inet_pton(), connect() */

59

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

72

73

*/

73

74

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

74

75

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

75

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

76

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

76

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

77

unlinkat() */

78

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

77

79

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

78

80

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

79

81

argp_state, struct argp,

91

93

argz_delete(), argz_append(),

92

94

argz_stringify(), argz_add(),

93

95

argz_count() */

96

#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

141

146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

180

185

perror(print_text);

181

186

}

182

187

183

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

188

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

184

189

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

185

190

va_list ap;

186

191

va_start (ap, format);

195

200

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

196

201

* "buffer_length" is how much is already used.

197

202

*/

203

__attribute__((nonnull, warn_unused_result))

198

204

size_t incbuffer(char **buffer, size_t buffer_length,

199

205

size_t buffer_capacity){

200

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

213

219

}

214

220

215

221

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

222

__attribute__((nonnull, warn_unused_result))

216

223

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

217

224

int af, server **current_server){

218

225

int ret;

227

234

.af = af };

228

235

if(new_server->ip == NULL){

229

236

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

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);

230

252

return false;

231

253

}

232

254

/* Special case of first server */

234

256

new_server->next = new_server;

235

257

new_server->prev = new_server;

236

258

*current_server = new_server;

237

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

238

259

} else {

260

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

239

261

new_server->next = *current_server;

240

262

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

241

263

new_server->prev->next = new_server;

242

264

(*current_server)->prev = new_server;

243

265

}

244

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

245

if(ret == -1){

246

perror_plus("clock_gettime");

247

return false;

248

}

249

266

return true;

250

267

}

251

268

252

269

/*

253

270

* Initialize GPGME.

254

271

*/

255

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

256

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){

257

277

gpgme_error_t rc;

258

278

gpgme_engine_info_t engine_info;

259

279

260

280

/*

261

281

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

262

282

*/

263

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

264

284

int ret;

265

285

int fd;

266

286

gpgme_data_t pgp_data;

347

367

* Decrypt OpenPGP data.

348

368

* Returns -1 on error

349

369

*/

370

__attribute__((nonnull, warn_unused_result))

350

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

351

372

size_t crypto_size,

352

373

char **plaintext,

472

493

return plaintext_length;

473

494

}

474

495

475

static const char * safer_gnutls_strerror(int value){

496

__attribute__((warn_unused_result))

497

static const char *safer_gnutls_strerror(int value){

476

498

const char *ret = gnutls_strerror(value);

477

499

if(ret == NULL)

478

500

ret = "(unknown)";

480

502

}

481

503

482

504

/* GnuTLS log function callback */

505

__attribute__((nonnull))

483

506

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

484

507

const char* string){

485

508

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

486

509

}

487

510

511

__attribute__((nonnull, warn_unused_result))

488

512

static int init_gnutls_global(const char *pubkeyfilename,

489

513

const char *seckeyfilename,

490

514

mandos_context *mc){

564

588

return -1;

565

589

}

566

590

591

__attribute__((nonnull, warn_unused_result))

567

592

static int init_gnutls_session(gnutls_session_t *session,

568

593

mandos_context *mc){

569

594

int ret;

626

651

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

627

652

628

653

/* Called when a Mandos server is found */

654

__attribute__((nonnull, warn_unused_result))

629

655

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

630

656

AvahiIfIndex if_index,

631

657

int af, mandos_context *mc){

632

658

int ret, tcp_sd = -1;

633

659

ssize_t sret;

634

union {

635

struct sockaddr_in in;

636

struct sockaddr_in6 in6;

637

} to;

660

struct sockaddr_storage to;

638

661

char *buffer = NULL;

639

662

char *decrypted_buffer = NULL;

640

663

size_t buffer_length = 0;

721

744

722

745

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

723

746

if(af == AF_INET6){

724

to.in6.sin6_family = (sa_family_t)af;

725

ret = inet_pton(af, ip, &to.in6.sin6_addr);

747

((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;

748

ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);

726

749

} else { /* IPv4 */

727

to.in.sin_family = (sa_family_t)af;

728

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

750

((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;

751

ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);

729

752

}

730

753

if(ret < 0 ){

731

754

int e = errno;

740

763

goto mandos_end;

741

764

}

742

765

if(af == AF_INET6){

743

to.in6.sin6_port = htons(port);

744

#ifdef __GNUC__

745

#pragma GCC diagnostic push

746

#pragma GCC diagnostic ignored "-Wstrict-aliasing"

747

#endif

748

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

749

(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower */

750

#ifdef __GNUC__

751

#pragma GCC diagnostic pop

752

#endif

766

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

767

if(IN6_IS_ADDR_LINKLOCAL

768

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

753

769

if(if_index == AVAHI_IF_UNSPEC){

754

770

fprintf_plus(stderr, "An IPv6 link-local address is"

755

771

" incomplete without a network interface\n");

757

773

goto mandos_end;

758

774

}

759

775

/* Set the network interface number as scope */

760

to.in6.sin6_scope_id = (uint32_t)if_index;

776

((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;

761

777

}

762

778

} else {

763

to.in.sin_port = htons(port);

779

((struct sockaddr_in *)&to)->sin_port = htons(port);

764

780

}

765

781

766

782

if(quit_now){

783

799

}

784

800

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

785

801

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

786

const char *pcret;

787

802

if(af == AF_INET6){

788

pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,

789

sizeof(addrstr));

803

ret = getnameinfo((struct sockaddr *)&to,

804

sizeof(struct sockaddr_in6),

805

addrstr, sizeof(addrstr), NULL, 0,

806

NI_NUMERICHOST);

790

807

} else {

791

pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,

792

sizeof(addrstr));

808

ret = getnameinfo((struct sockaddr *)&to,

809

sizeof(struct sockaddr_in),

810

addrstr, sizeof(addrstr), NULL, 0,

811

NI_NUMERICHOST);

793

812

}

794

if(pcret == NULL){

795

perror_plus("inet_ntop");

796

} else {

797

if(strcmp(addrstr, ip) != 0){

798

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

799

}

813

if(ret == EAI_SYSTEM){

814

perror_plus("getnameinfo");

815

} else if(ret != 0) {

816

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

817

} else if(strcmp(addrstr, ip) != 0){

818

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

800

819

}

801

820

}

802

821

806

825

}

807

826

808

827

if(af == AF_INET6){

809

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

828

ret = connect(tcp_sd, (struct sockaddr *)&to,

829

sizeof(struct sockaddr_in6));

810

830

} else {

811

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

831

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

832

sizeof(struct sockaddr_in));

812

833

}

813

834

if(ret < 0){

814

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

835

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

815

836

int e = errno;

816

837

perror_plus("connect");

817

838

errno = e;

1032

1053

return retval;

1033

1054

}

1034

1055

1056

__attribute__((nonnull))

1035

1057

static void resolve_callback(AvahiSServiceResolver *r,

1036

1058

AvahiIfIndex interface,

1037

1059

AvahiProtocol proto,

1045

1067

AVAHI_GCC_UNUSED AvahiStringList *txt,

1046

1068

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1047

1069

flags,

1048

void* mc){

1070

void *mc){

1049

1071

if(r == NULL){

1050

1072

return;

1051

1073

}

1054

1076

timed out */

1055

1077

1056

1078

if(quit_now){

1079

avahi_s_service_resolver_free(r);

1057

1080

return;

1058

1081

}

1059

1082

1104

1127

const char *domain,

1105

1128

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1106

1129

flags,

1107

void* mc){

1130

void *mc){

1108

1131

if(b == NULL){

1109

1132

return;

1110

1133

}

1170

1193

errno = old_errno;

1171

1194

}

1172

1195

1196

__attribute__((nonnull, warn_unused_result))

1173

1197

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

1174

1198

int ret;

1175

1199

error_t ret_errno;

1194

1218

return true;

1195

1219

}

1196

1220

1221

__attribute__((nonnull, warn_unused_result))

1197

1222

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

1198

1223

1199

1224

/* Reject the loopback device */

1241

1266

* corresponds to an acceptable network device.

1242

1267

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

1243

1268

*/

1269

__attribute__((nonnull, warn_unused_result))

1244

1270

int good_interface(const struct dirent *if_entry){

1245

1271

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

1246

1272

return 0;

1264

1290

/*

1265

1291

* This function determines if a network interface is up.

1266

1292

*/

1293

__attribute__((nonnull, warn_unused_result))

1267

1294

bool interface_is_up(const char *interface){

1268

1295

struct ifreq ifr;

1269

1296

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

1280

1307

/*

1281

1308

* This function determines if a network interface is running

1282

1309

*/

1310

__attribute__((nonnull, warn_unused_result))

1283

1311

bool interface_is_running(const char *interface){

1284

1312

struct ifreq ifr;

1285

1313

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

1293

1321

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

1294

1322

}

1295

1323

1324

__attribute__((nonnull, pure, warn_unused_result))

1296

1325

int notdotentries(const struct dirent *direntry){

1297

1326

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

1298

1327

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

1305

1334

}

1306

1335

1307

1336

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

1337

__attribute__((nonnull, warn_unused_result))

1308

1338

int runnable_hook(const struct dirent *direntry){

1309

1339

int ret;

1310

1340

size_t sret;

1318

1348

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

1319

1349

"abcdefghijklmnopqrstuvwxyz"

1320

1350

"0123456789"

1321

"_-");

1351

"_.-");

1322

1352

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

1323

1353

/* Contains non-allowed characters */

1324

1354

if(debug){

1328

1358

return 0;

1329

1359

}

1330

1360

1331

char *fullname = NULL;

1332

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

1333

if(ret < 0){

1334

perror_plus("asprintf");

1335

return 0;

1336

}

1337

1338

ret = stat(fullname, &st);

1361

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

1339

1362

if(ret == -1){

1340

1363

if(debug){

1341

1364

perror_plus("Could not stat hook");

1365

1388

return 1;

1366

1389

}

1367

1390

1391

__attribute__((nonnull, warn_unused_result))

1368

1392

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1369

1393

mandos_context *mc){

1370

1394

int ret;

1374

1398

1375

1399

while(true){

1376

1400

if(mc->current_server == NULL){

1377

if (debug){

1401

if(debug){

1378

1402

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

1379

1403

" No timeout!\n");

1380

1404

}

1381

1405

ret = avahi_simple_poll_iterate(s, -1);

1382

1406

} else {

1383

if (debug){

1407

if(debug){

1384

1408

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

1385

1409

" it, or wait\n");

1386

1410

}

1403

1427

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

1404

1428

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

1405

1429

1406

if (debug){

1430

if(debug){

1407

1431

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

1408

1432

block_time);

1409

1433

}

1431

1455

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

1432

1456

}

1433

1457

if(ret != 0){

1434

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

1458

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

1435

1459

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

1436

1460

}

1437

1461

}

1439

1463

}

1440

1464

1441

1465

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

1466

__attribute__((warn_unused_result))

1442

1467

error_t raise_privileges(void){

1443

1468

error_t old_errno = errno;

1444

1469

error_t ret_errno = 0;

1445

1470

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

1446

1471

ret_errno = errno;

1447

perror_plus("seteuid");

1448

1472

}

1449

1473

errno = old_errno;

1450

1474

return ret_errno;

1451

1475

}

1452

1476

1453

1477

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

1478

__attribute__((warn_unused_result))

1454

1479

error_t raise_privileges_permanently(void){

1455

1480

error_t old_errno = errno;

1456

1481

error_t ret_errno = raise_privileges();

1460

1485

}

1461

1486

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

1462

1487

ret_errno = errno;

1463

perror_plus("seteuid");

1464

1488

}

1465

1489

errno = old_errno;

1466

1490

return ret_errno;

1467

1491

}

1468

1492

1469

1493

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

1494

__attribute__((warn_unused_result))

1470

1495

error_t lower_privileges(void){

1471

1496

error_t old_errno = errno;

1472

1497

error_t ret_errno = 0;

1473

1498

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

1474

1499

ret_errno = errno;

1475

perror_plus("seteuid");

1476

1500

}

1477

1501

errno = old_errno;

1478

1502

return ret_errno;

1479

1503

}

1480

1504

1481

1505

/* Lower privileges permanently */

1506

__attribute__((warn_unused_result))

1482

1507

error_t lower_privileges_permanently(void){

1483

1508

error_t old_errno = errno;

1484

1509

error_t ret_errno = 0;

1485

1510

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

1486

1511

ret_errno = errno;

1487

perror_plus("setuid");

1488

1512

}

1489

1513

errno = old_errno;

1490

1514

return ret_errno;

1491

1515

}

1492

1516

1493

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

1517

__attribute__((nonnull))

1518

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

1494

1519

const float delay){

1495

struct dirent **direntries;

1496

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

1497

alphasort);

1520

struct dirent **direntries = NULL;

1521

if(hookdir_fd == -1){

1522

hookdir_fd = open(hookdir, O_RDONLY);

1523

if(hookdir_fd == -1){

1524

if(errno == ENOENT){

1525

if(debug){

1526

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

1527

" found\n", hookdir);

1528

}

1529

} else {

1530

perror_plus("open");

1531

}

1532

return;

1533

}

1534

}

1535

#ifdef __GLIBC__

1536

#if __GLIBC_PREREQ(2, 15)

1537

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

1538

runnable_hook, alphasort);

1539

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

1540

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

1541

alphasort);

1542

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

1543

#else /* not __GLIBC__ */

1544

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

1545

alphasort);

1546

#endif /* not __GLIBC__ */

1498

1547

if(numhooks == -1){

1499

if(errno == ENOENT){

1500

if(debug){

1501

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

1502

" found\n", hookdir);

1503

}

1504

} else {

1505

perror_plus("scandir");

1548

perror_plus("scandir");

1549

return;

1550

}

1551

struct dirent *direntry;

1552

int ret;

1553

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

1554

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

1555

direntry = direntries[i];

1556

if(debug){

1557

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

1558

direntry->d_name);

1506

1559

}

1507

} else {

1508

struct dirent *direntry;

1509

int ret;

1510

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

1511

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

1512

direntry = direntries[i];

1513

char *fullname = NULL;

1514

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

1515

if(ret < 0){

1560

pid_t hook_pid = fork();

1561

if(hook_pid == 0){

1562

/* Child */

1563

/* Raise privileges */

1564

errno = raise_privileges_permanently();

1565

if(errno != 0){

1566

perror_plus("Failed to raise privileges");

1567

_exit(EX_NOPERM);

1568

}

1569

/* Set group */

1570

errno = 0;

1571

ret = setgid(0);

1572

if(ret == -1){

1573

perror_plus("setgid");

1574

_exit(EX_NOPERM);

1575

}

1576

/* Reset supplementary groups */

1577

errno = 0;

1578

ret = setgroups(0, NULL);

1579

if(ret == -1){

1580

perror_plus("setgroups");

1581

_exit(EX_NOPERM);

1582

}

1583

ret = dup2(devnull, STDIN_FILENO);

1584

if(ret == -1){

1585

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

1586

_exit(EX_OSERR);

1587

}

1588

ret = close(devnull);

1589

if(ret == -1){

1590

perror_plus("close");

1591

_exit(EX_OSERR);

1592

}

1593

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1594

if(ret == -1){

1595

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

1596

_exit(EX_OSERR);

1597

}

1598

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

1599

if(ret == -1){

1600

perror_plus("setenv");

1601

_exit(EX_OSERR);

1602

}

1603

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

1604

if(ret == -1){

1605

perror_plus("setenv");

1606

_exit(EX_OSERR);

1607

}

1608

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

1609

if(ret == -1){

1610

perror_plus("setenv");

1611

_exit(EX_OSERR);

1612

}

1613

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

1614

if(ret == -1){

1615

perror_plus("setenv");

1616

_exit(EX_OSERR);

1617

}

1618

char *delaystring;

1619

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

1620

if(ret == -1){

1516

1621

perror_plus("asprintf");

1517

continue;

1518

}

1519

if(debug){

1520

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

1521

direntry->d_name);

1522

}

1523

pid_t hook_pid = fork();

1524

if(hook_pid == 0){

1525

/* Child */

1526

/* Raise privileges */

1527

raise_privileges_permanently();

1528

/* Set group */

1529

errno = 0;

1530

ret = setgid(0);

1531

if(ret == -1){

1532

perror_plus("setgid");

1533

}

1534

/* Reset supplementary groups */

1535

errno = 0;

1536

ret = setgroups(0, NULL);

1537

if(ret == -1){

1538

perror_plus("setgroups");

1539

}

1540

dup2(devnull, STDIN_FILENO);

1541

close(devnull);

1542

dup2(STDERR_FILENO, STDOUT_FILENO);

1543

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

1544

if(ret == -1){

1545

perror_plus("setenv");

1546

_exit(EX_OSERR);

1547

}

1548

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

1549

if(ret == -1){

1550

perror_plus("setenv");

1551

_exit(EX_OSERR);

1552

}

1553

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

1554

if(ret == -1){

1555

perror_plus("setenv");

1556

_exit(EX_OSERR);

1557

}

1558

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

1559

if(ret == -1){

1560

perror_plus("setenv");

1561

_exit(EX_OSERR);

1562

}

1563

char *delaystring;

1564

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

1565

if(ret == -1){

1566

perror_plus("asprintf");

1567

_exit(EX_OSERR);

1568

}

1569

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

1570

if(ret == -1){

1571

free(delaystring);

1572

perror_plus("setenv");

1573

_exit(EX_OSERR);

1574

}

1622

_exit(EX_OSERR);

1623

}

1624

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

1625

if(ret == -1){

1575

1626

free(delaystring);

1576

if(connect_to != NULL){

1577

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

1578

if(ret == -1){

1579

perror_plus("setenv");

1580

_exit(EX_OSERR);

1581

}

1582

}

1583

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

1584

perror_plus("execl");

1585

_exit(EXIT_FAILURE);

1586

}

1627

perror_plus("setenv");

1628

_exit(EX_OSERR);

1629

}

1630

free(delaystring);

1631

if(connect_to != NULL){

1632

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

1633

if(ret == -1){

1634

perror_plus("setenv");

1635

_exit(EX_OSERR);

1636

}

1637

}

1638

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

1639

if(hook_fd == -1){

1640

perror_plus("openat");

1641

_exit(EXIT_FAILURE);

1642

}

1643

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

1644

perror_plus("close");

1645

_exit(EXIT_FAILURE);

1646

}

1647

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

1648

environ) == -1){

1649

perror_plus("fexecve");

1650

_exit(EXIT_FAILURE);

1651

}

1652

} else {

1653

if(hook_pid == -1){

1654

perror_plus("fork");

1655

free(direntry);

1656

continue;

1657

}

1658

int status;

1659

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

1660

perror_plus("waitpid");

1661

free(direntry);

1662

continue;

1663

}

1664

if(WIFEXITED(status)){

1665

if(WEXITSTATUS(status) != 0){

1666

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

1667

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

1668

WEXITSTATUS(status));

1669

free(direntry);

1670

continue;

1671

}

1672

} else if(WIFSIGNALED(status)){

1673

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

1674

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

1675

WTERMSIG(status));

1676

free(direntry);

1677

continue;

1587

1678

} else {

1588

int status;

1589

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

1590

perror_plus("waitpid");

1591

free(fullname);

1592

continue;

1593

}

1594

if(WIFEXITED(status)){

1595

if(WEXITSTATUS(status) != 0){

1596

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

1597

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

1598

WEXITSTATUS(status));

1599

free(fullname);

1600

continue;

1601

}

1602

} else if(WIFSIGNALED(status)){

1603

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

1604

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

1605

WTERMSIG(status));

1606

free(fullname);

1607

continue;

1608

} else {

1609

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

1610

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

1611

free(fullname);

1612

continue;

1613

}

1614

}

1615

free(fullname);

1616

if(debug){

1617

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

1618

direntry->d_name);

1619

}

1620

}

1621

close(devnull);

1622

}

1623

return true;

1679

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

1680

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

1681

free(direntry);

1682

continue;

1683

}

1684

}

1685

if(debug){

1686

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

1687

direntry->d_name);

1688

}

1689

free(direntry);

1690

}

1691

free(direntries);

1692

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

1693

perror_plus("close");

1694

} else {

1695

hookdir_fd = -1;

1696

}

1697

close(devnull);

1624

1698

}

1625

1699

1700

__attribute__((nonnull, warn_unused_result))

1626

1701

error_t bring_up_interface(const char *const interface,

1627

1702

const float delay){

1628

int sd = -1;

1629

1703

error_t old_errno = errno;

1630

error_t ret_errno = 0;

1631

int ret, ret_setflags;

1704

int ret;

1632

1705

struct ifreq network;

1633

1706

unsigned int if_index = if_nametoindex(interface);

1634

1707

if(if_index == 0){

1643

1716

}

1644

1717

1645

1718

if(not interface_is_up(interface)){

1646

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

1719

error_t ret_errno = 0, ioctl_errno = 0;

1720

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

1647

1721

ret_errno = errno;

1648

1722

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

1649

1723

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

1724

errno = old_errno;

1650

1725

return ret_errno;

1651

1726

}

1652

network.ifr_flags |= IFF_UP;

1727

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

1653

1728

1654

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1655

if(sd < 0){

1729

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

1730

if(sd == -1){

1656

1731

ret_errno = errno;

1657

1732

perror_plus("socket");

1658

1733

errno = old_errno;

1659

1734

return ret_errno;

1660

1735

}

1661

1736

1662

1737

if(quit_now){

1663

close(sd);

1738

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

1739

if(ret == -1){

1740

perror_plus("close");

1741

}

1664

1742

errno = old_errno;

1665

1743

return EINTR;

1666

1744

}

1670

1748

interface);

1671

1749

}

1672

1750

1673

/* Raise priviliges */

1674

raise_privileges();

1751

/* Raise privileges */

1752

ret_errno = raise_privileges();

1753

if(ret_errno != 0){

1754

errno = ret_errno;

1755

perror_plus("Failed to raise privileges");

1756

}

1675

1757

1676

1758

#ifdef __linux__

1677

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1678

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

1679

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

1680

bool restore_loglevel = true;

1681

if(ret_linux == -1){

1682

restore_loglevel = false;

1683

perror_plus("klogctl");

1759

int ret_linux;

1760

bool restore_loglevel = false;

1761

if(ret_errno == 0){

1762

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1763

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

1764

ret_linux = klogctl(8, NULL, 5);

1765

if(ret_linux == -1){

1766

perror_plus("klogctl");

1767

} else {

1768

restore_loglevel = true;

1769

}

1684

1770

}

1685

1771

#endif /* __linux__ */

1686

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

1687

ret_errno = errno;

1772

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

1773

ioctl_errno = errno;

1688

1774

#ifdef __linux__

1689

1775

if(restore_loglevel){

1690

1776

ret_linux = klogctl(7, NULL, 0);

1694

1780

}

1695

1781

#endif /* __linux__ */

1696

1782

1697

/* Lower privileges */

1698

lower_privileges();

1783

/* If raise_privileges() succeeded above */

1784

if(ret_errno == 0){

1785

/* Lower privileges */

1786

ret_errno = lower_privileges();

1787

if(ret_errno != 0){

1788

errno = ret_errno;

1789

perror_plus("Failed to lower privileges");

1790

}

1791

}

1699

1792

1700

1793

/* Close the socket */

1701

1794

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

1704

1797

}

1705

1798

1706

1799

if(ret_setflags == -1){

1707

errno = ret_errno;

1800

errno = ioctl_errno;

1708

1801

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1709

1802

errno = old_errno;

1710

return ret_errno;

1803

return ioctl_errno;

1711

1804

}

1712

1805

} else if(debug){

1713

1806

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

1731

1824

return 0;

1732

1825

}

1733

1826

1827

__attribute__((nonnull, warn_unused_result))

1734

1828

error_t take_down_interface(const char *const interface){

1735

1829

error_t old_errno = errno;

1736

1830

struct ifreq network;

1741

1835

return ENXIO;

1742

1836

}

1743

1837

if(interface_is_up(interface)){

1744

error_t ret_errno = 0;

1838

error_t ret_errno = 0, ioctl_errno = 0;

1745

1839

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

1746

1840

ret_errno = errno;

1747

1841

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

1748

1842

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

1843

errno = old_errno;

1749

1844

return ret_errno;

1750

1845

}

1751

1846

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

1752

1847

1753

1848

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

1754

if(sd < 0){

1849

if(sd == -1){

1755

1850

ret_errno = errno;

1756

1851

perror_plus("socket");

1757

1852

errno = old_errno;

1763

1858

interface);

1764

1859

}

1765

1860

1766

/* Raise priviliges */

1767

raise_privileges();

1861

/* Raise privileges */

1862

ret_errno = raise_privileges();

1863

if(ret_errno != 0){

1864

errno = ret_errno;

1865

perror_plus("Failed to raise privileges");

1866

}

1768

1867

1769

1868

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

1770

ret_errno = errno;

1869

ioctl_errno = errno;

1771

1870

1772

/* Lower privileges */

1773

lower_privileges();

1871

/* If raise_privileges() succeeded above */

1872

if(ret_errno == 0){

1873

/* Lower privileges */

1874

ret_errno = lower_privileges();

1875

if(ret_errno != 0){

1876

errno = ret_errno;

1877

perror_plus("Failed to lower privileges");

1878

}

1879

}

1774

1880

1775

1881

/* Close the socket */

1776

1882

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

1779

1885

}

1780

1886

1781

1887

if(ret_setflags == -1){

1782

errno = ret_errno;

1888

errno = ioctl_errno;

1783

1889

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1784

1890

errno = old_errno;

1785

return ret_errno;

1891

return ioctl_errno;

1786

1892

}

1787

1893

} else if(debug){

1788

1894

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

1796

1902

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

1797

1903

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

1798

1904

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

1799

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

1905

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

1800

1906

.interfaces = NULL, .interfaces_size = 0 };

1801

1907

AvahiSServiceBrowser *sb = NULL;

1802

1908

error_t ret_errno;

1806

1912

int exitcode = EXIT_SUCCESS;

1807

1913

char *interfaces_to_take_down = NULL;

1808

1914

size_t interfaces_to_take_down_size = 0;

1809

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

1810

bool tempdir_created = false;

1915

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

1916

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

1917

char *tempdir = NULL;

1811

1918

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1812

1919

const char *seckey = PATHDIR "/" SECKEY;

1813

1920

const char *pubkey = PATHDIR "/" PUBKEY;

1995

2102

/* Work around Debian bug #633582:

1996

2103

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

1997

2104

1998

/* Re-raise priviliges */

1999

if(raise_privileges() == 0){

2105

/* Re-raise privileges */

2106

ret_errno = raise_privileges();

2107

if(ret_errno != 0){

2108

errno = ret_errno;

2109

perror_plus("Failed to raise privileges");

2110

} else {

2000

2111

struct stat st;

2001

2112

2002

2113

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

2042

2153

}

2043

2154

2044

2155

/* Lower privileges */

2045

lower_privileges();

2156

ret_errno = lower_privileges();

2157

if(ret_errno != 0){

2158

errno = ret_errno;

2159

perror_plus("Failed to lower privileges");

2160

}

2046

2161

}

2047

2162

}

2048

2163

2074

2189

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

2075

2190

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

2076

2191

}

2077

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

2078

interfaces_hooks : "", delay)){

2079

goto end;

2080

}

2192

run_network_hooks("start", interfaces_hooks != NULL ?

2193

interfaces_hooks : "", delay);

2081

2194

}

2082

2195

2083

2196

if(not debug){

2161

2274

2162

2275

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

2163

2276

if(mc.interfaces == NULL){

2164

struct dirent **direntries;

2277

struct dirent **direntries = NULL;

2165

2278

/* Look for any good interfaces */

2166

2279

ret = scandir(sys_class_net, &direntries, good_interface,

2167

2280

alphasort);

2173

2286

if(ret_errno != 0){

2174

2287

errno = ret_errno;

2175

2288

perror_plus("argz_add");

2289

free(direntries[i]);

2176

2290

continue;

2177

2291

}

2178

2292

if(debug){

2179

2293

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

2180

2294

direntries[i]->d_name);

2181

2295

}

2296

free(direntries[i]);

2182

2297

}

2183

2298

free(direntries);

2184

2299

} else {

2185

free(direntries);

2300

if(ret == 0){

2301

free(direntries);

2302

}

2186

2303

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

2187

2304

exitcode = EXIT_FAILURE;

2188

2305

goto end;

2211

2328

break;

2212

2329

}

2213

2330

bool interface_was_up = interface_is_up(interface);

2214

ret = bring_up_interface(interface, delay);

2331

errno = bring_up_interface(interface, delay);

2215

2332

if(not interface_was_up){

2216

if(ret != 0){

2217

errno = ret;

2333

if(errno != 0){

2218

2334

perror_plus("Failed to bring up interface");

2219

2335

} else {

2220

ret_errno = argz_add(&interfaces_to_take_down,

2221

&interfaces_to_take_down_size,

2222

interface);

2223

if(ret_errno != 0){

2224

errno = ret_errno;

2336

errno = argz_add(&interfaces_to_take_down,

2337

&interfaces_to_take_down_size,

2338

interface);

2339

if(errno != 0){

2225

2340

perror_plus("argz_add");

2226

2341

}

2227

2342

}

2258

2373

goto end;

2259

2374

}

2260

2375

2261

if(mkdtemp(tempdir) == NULL){

2376

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

2377

tempdir = mkdtemp(run_tempdir);

2378

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

2379

if(debug){

2380

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

2381

run_tempdir, old_tempdir);

2382

}

2383

tempdir = mkdtemp(old_tempdir);

2384

}

2385

if(tempdir == NULL){

2262

2386

perror_plus("mkdtemp");

2263

2387

goto end;

2264

2388

}

2265

tempdir_created = true;

2266

2389

2267

2390

if(quit_now){

2268

2391

goto end;

2343

2466

sleep((unsigned int)retry_interval);

2344

2467

}

2345

2468

2346

if (not quit_now){

2469

if(not quit_now){

2347

2470

exitcode = EXIT_SUCCESS;

2348

2471

}

2349

2472

2404

2527

if(debug){

2405

2528

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

2406

2529

}

2407

2530

2408

2531

ret = avahi_loop_with_timeout(simple_poll,

2409

2532

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

2410

2533

if(debug){

2446

2569

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

2447

2570

while(mc.current_server != NULL){

2448

2571

server *next = mc.current_server->next;

2572

#ifdef __GNUC__

2573

#pragma GCC diagnostic push

2574

#pragma GCC diagnostic ignored "-Wcast-qual"

2575

#endif

2576

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

2577

#ifdef __GNUC__

2578

#pragma GCC diagnostic pop

2579

#endif

2449

2580

free(mc.current_server);

2450

2581

mc.current_server = next;

2451

2582

}

2452

2583

}

2453

2584

2454

/* Re-raise priviliges */

2585

/* Re-raise privileges */

2455

2586

{

2456

raise_privileges();

2457

2458

/* Run network hooks */

2459

run_network_hooks("stop", interfaces_hooks != NULL ?

2460

interfaces_hooks : "", delay);

2461

2462

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

2463

{

2464

char *interface = NULL;

2465

while((interface=argz_next(interfaces_to_take_down,

2466

interfaces_to_take_down_size,

2467

interface))){

2468

ret_errno = take_down_interface(interface);

2469

if(ret_errno != 0){

2470

errno = ret_errno;

2471

perror_plus("Failed to take down interface");

2472

}

2473

}

2474

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

2475

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

2476

" down\n");

2477

}

2478

}

2479

2480

lower_privileges_permanently();

2587

ret_errno = raise_privileges();

2588

if(ret_errno != 0){

2589

errno = ret_errno;

2590

perror_plus("Failed to raise privileges");

2591

} else {

2592

2593

/* Run network hooks */

2594

run_network_hooks("stop", interfaces_hooks != NULL ?

2595

interfaces_hooks : "", delay);

2596

2597

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

2598

{

2599

char *interface = NULL;

2600

while((interface=argz_next(interfaces_to_take_down,

2601

interfaces_to_take_down_size,

2602

interface))){

2603

ret_errno = take_down_interface(interface);

2604

if(ret_errno != 0){

2605

errno = ret_errno;

2606

perror_plus("Failed to take down interface");

2607

}

2608

}

2609

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

2610

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

2611

" down\n");

2612

}

2613

}

2614

}

2615

2616

ret_errno = lower_privileges_permanently();

2617

if(ret_errno != 0){

2618

errno = ret_errno;

2619

perror_plus("Failed to lower privileges permanently");

2620

}

2481

2621

}

2482

2622

2483

2623

free(interfaces_to_take_down);

2484

2624

free(interfaces_hooks);

2485

2625

2486

2626

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

2487

if(tempdir_created){

2627

if(tempdir != NULL){

2488

2628

struct dirent **direntries = NULL;

2489

struct dirent *direntry = NULL;

2490

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

2491

alphasort);

2492

if (numentries > 0){

2493

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

2494

direntry = direntries[i];

2495

char *fullname = NULL;

2496

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

2497

direntry->d_name);

2498

if(ret < 0){

2499

perror_plus("asprintf");

2500

continue;

2501

}

2502

ret = remove(fullname);

2503

if(ret == -1){

2504

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

2505

strerror(errno));

2506

}

2507

free(fullname);

2629

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

2630

O_NOFOLLOW));

2631

if(tempdir_fd == -1){

2632

perror_plus("open");

2633

} else {

2634

#ifdef __GLIBC__

2635

#if __GLIBC_PREREQ(2, 15)

2636

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

2637

notdotentries, alphasort);

2638

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

2639

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

2640

alphasort);

2641

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

2642

#else /* not __GLIBC__ */

2643

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

2644

alphasort);

2645

#endif /* not __GLIBC__ */

2646

if(numentries >= 0){

2647

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

2648

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

2649

if(ret == -1){

2650

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

2651

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

2652

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

2653

}

2654

free(direntries[i]);

2655

}

2656

2657

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

2658

free(direntries);

2659

if(numentries == -1){

2660

perror_plus("scandir");

2661

}

2662

ret = rmdir(tempdir);

2663

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

2664

perror_plus("rmdir");

2665

}

2508

2666

}

2509

}

2510

2511

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

2512

free(direntries);

2513

if (numentries == -1){

2514

perror_plus("scandir");

2515

}

2516

ret = rmdir(tempdir);

2517

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

2518

perror_plus("rmdir");

2667

TEMP_FAILURE_RETRY(close(tempdir_fd));

2519

2668

}

2520

2669

}

2521

2670