/mandos/trunk : revision 693

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

55

opendir(), DIR */

56

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

57

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

58

inet_pton(), connect() */

58

inet_pton(), connect(),

59

getnameinfo() */

59

60

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

60

61

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

61

62

*/

73

74

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

74

75

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

75

76

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

76

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

77

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

77

78

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

78

79

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

79

80

argp_state, struct argp,

91

92

argz_delete(), argz_append(),

92

93

argz_stringify(), argz_add(),

93

94

argz_count() */

95

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

96

EAI_SYSTEM, gai_strerror() */

94

97

95

98

#ifdef __linux__

96

99

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

138

141

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

139

142

char *connect_to = NULL;

140

143

const char *hookdir = HOOKDIR;

144

int hookdir_fd = -1;

141

145

uid_t uid = 65534;

142

146

gid_t gid = 65534;

143

147

180

184

perror(print_text);

181

185

}

182

186

183

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

187

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

184

188

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

185

189

va_list ap;

186

190

va_start (ap, format);

195

199

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

196

200

* "buffer_length" is how much is already used.

197

201

*/

202

__attribute__((nonnull, warn_unused_result))

198

203

size_t incbuffer(char **buffer, size_t buffer_length,

199

204

size_t buffer_capacity){

200

205

if(buffer_length + BUFFER_SIZE > buffer_capacity){

201

*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

202

if(buffer == NULL){

206

char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

207

if(new_buf == NULL){

208

int old_errno = errno;

209

free(*buffer);

210

errno = old_errno;

211

*buffer = NULL;

203

212

return 0;

204

213

}

214

*buffer = new_buf;

205

215

buffer_capacity += BUFFER_SIZE;

206

216

}

207

217

return buffer_capacity;

208

218

}

209

219

210

220

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

221

__attribute__((nonnull, warn_unused_result))

211

222

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

212

223

int af, server **current_server){

213

224

int ret;

224

235

perror_plus("strdup");

225

236

return false;

226

237

}

238

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

239

if(ret == -1){

240

perror_plus("clock_gettime");

241

return false;

242

}

227

243

/* Special case of first server */

228

244

if(*current_server == NULL){

229

245

new_server->next = new_server;

230

246

new_server->prev = new_server;

231

247

*current_server = new_server;

232

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

233

248

} else {

249

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

234

250

new_server->next = *current_server;

235

251

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

236

252

new_server->prev->next = new_server;

237

253

(*current_server)->prev = new_server;

238

254

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

244

255

return true;

245

256

}

246

257

247

258

/*

248

259

* Initialize GPGME.

249

260

*/

250

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

251

const char *tempdir, mandos_context *mc){

261

__attribute__((nonnull, warn_unused_result))

262

static bool init_gpgme(const char * const seckey,

263

const char * const pubkey,

264

const char * const tempdir,

265

mandos_context *mc){

252

266

gpgme_error_t rc;

253

267

gpgme_engine_info_t engine_info;

254

268

255

269

/*

256

270

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

257

271

*/

258

bool import_key(const char *filename){

272

bool import_key(const char * const filename){

259

273

int ret;

260

274

int fd;

261

275

gpgme_data_t pgp_data;

342

356

* Decrypt OpenPGP data.

343

357

* Returns -1 on error

344

358

*/

359

__attribute__((nonnull, warn_unused_result))

345

360

static ssize_t pgp_packet_decrypt(const char *cryptotext,

346

361

size_t crypto_size,

347

362

char **plaintext,

467

482

return plaintext_length;

468

483

}

469

484

470

static const char * safer_gnutls_strerror(int value){

485

__attribute__((warn_unused_result))

486

static const char *safer_gnutls_strerror(int value){

471

487

const char *ret = gnutls_strerror(value);

472

488

if(ret == NULL)

473

489

ret = "(unknown)";

475

491

}

476

492

477

493

/* GnuTLS log function callback */

494

__attribute__((nonnull))

478

495

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

479

496

const char* string){

480

497

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

481

498

}

482

499

500

__attribute__((nonnull, warn_unused_result))

483

501

static int init_gnutls_global(const char *pubkeyfilename,

484

502

const char *seckeyfilename,

485

503

mandos_context *mc){

559

577

return -1;

560

578

}

561

579

580

__attribute__((nonnull, warn_unused_result))

562

581

static int init_gnutls_session(gnutls_session_t *session,

563

582

mandos_context *mc){

564

583

int ret;

621

640

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

622

641

623

642

/* Called when a Mandos server is found */

643

__attribute__((nonnull, warn_unused_result))

624

644

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

625

645

AvahiIfIndex if_index,

626

646

int af, mandos_context *mc){

627

647

int ret, tcp_sd = -1;

628

648

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

649

struct sockaddr_storage to;

633

650

char *buffer = NULL;

634

651

char *decrypted_buffer = NULL;

635

652

size_t buffer_length = 0;

716

733

717

734

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

718

735

if(af == AF_INET6){

719

to.in6.sin6_family = (sa_family_t)af;

720

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

736

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

737

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

721

738

} else { /* IPv4 */

722

to.in.sin_family = (sa_family_t)af;

723

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

739

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

740

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

724

741

}

725

742

if(ret < 0 ){

726

743

int e = errno;

735

752

goto mandos_end;

736

753

}

737

754

if(af == AF_INET6){

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

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

741

-Wunreachable-code*/

755

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

756

if(IN6_IS_ADDR_LINKLOCAL

757

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

742

758

if(if_index == AVAHI_IF_UNSPEC){

743

759

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

744

760

" incomplete without a network interface\n");

746

762

goto mandos_end;

747

763

}

748

764

/* Set the network interface number as scope */

749

to.in6.sin6_scope_id = (uint32_t)if_index;

765

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

750

766

}

751

767

} else {

752

to.in.sin_port = htons(port); /* Spurious warnings from

753

-Wconversion and

754

-Wunreachable-code */

768

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

755

769

}

756

770

757

771

if(quit_now){

774

788

}

775

789

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

776

790

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

777

const char *pcret;

778

791

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

792

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

793

sizeof(struct sockaddr_in6),

794

addrstr, sizeof(addrstr), NULL, 0,

795

NI_NUMERICHOST);

781

796

} else {

782

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

783

sizeof(addrstr));

797

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

798

sizeof(struct sockaddr_in),

799

addrstr, sizeof(addrstr), NULL, 0,

800

NI_NUMERICHOST);

784

801

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

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

789

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

790

}

802

if(ret == EAI_SYSTEM){

803

perror_plus("getnameinfo");

804

} else if(ret != 0) {

805

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

806

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

807

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

791

808

}

792

809

}

793

810

797

814

}

798

815

799

816

if(af == AF_INET6){

800

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

817

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

818

sizeof(struct sockaddr_in6));

801

819

} else {

802

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

820

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

821

sizeof(struct sockaddr_in));

803

822

}

804

823

if(ret < 0){

805

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

824

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

806

825

int e = errno;

807

826

perror_plus("connect");

808

827

errno = e;

1023

1042

return retval;

1024

1043

}

1025

1044

1045

__attribute__((nonnull))

1026

1046

static void resolve_callback(AvahiSServiceResolver *r,

1027

1047

AvahiIfIndex interface,

1028

1048

AvahiProtocol proto,

1036

1056

AVAHI_GCC_UNUSED AvahiStringList *txt,

1037

1057

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1038

1058

flags,

1039

void* mc){

1059

void *mc){

1040

1060

if(r == NULL){

1041

1061

return;

1042

1062

}

1095

1115

const char *domain,

1096

1116

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1097

1117

flags,

1098

void* mc){

1118

void *mc){

1099

1119

if(b == NULL){

1100

1120

return;

1101

1121

}

1161

1181

errno = old_errno;

1162

1182

}

1163

1183

1184

__attribute__((nonnull, warn_unused_result))

1164

1185

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

1165

1186

int ret;

1166

1187

error_t ret_errno;

1185

1206

return true;

1186

1207

}

1187

1208

1209

__attribute__((nonnull, warn_unused_result))

1188

1210

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

1189

1211

1190

1212

/* Reject the loopback device */

1232

1254

* corresponds to an acceptable network device.

1233

1255

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

1234

1256

*/

1257

__attribute__((nonnull, warn_unused_result))

1235

1258

int good_interface(const struct dirent *if_entry){

1236

1259

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

1237

1260

return 0;

1255

1278

/*

1256

1279

* This function determines if a network interface is up.

1257

1280

*/

1281

__attribute__((nonnull, warn_unused_result))

1258

1282

bool interface_is_up(const char *interface){

1259

1283

struct ifreq ifr;

1260

1284

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

1271

1295

/*

1272

1296

* This function determines if a network interface is running

1273

1297

*/

1298

__attribute__((nonnull, warn_unused_result))

1274

1299

bool interface_is_running(const char *interface){

1275

1300

struct ifreq ifr;

1276

1301

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

1284

1309

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

1285

1310

}

1286

1311

1312

__attribute__((nonnull, pure, warn_unused_result))

1287

1313

int notdotentries(const struct dirent *direntry){

1288

1314

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

1289

1315

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

1296

1322

}

1297

1323

1298

1324

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

1325

__attribute__((nonnull, warn_unused_result))

1299

1326

int runnable_hook(const struct dirent *direntry){

1300

1327

int ret;

1301

1328

size_t sret;

1309

1336

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

1310

1337

"abcdefghijklmnopqrstuvwxyz"

1311

1338

"0123456789"

1312

"_-");

1339

"_.-");

1313

1340

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

1314

1341

/* Contains non-allowed characters */

1315

1342

if(debug){

1319

1346

return 0;

1320

1347

}

1321

1348

1322

char *fullname = NULL;

1323

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

1324

if(ret < 0){

1325

perror_plus("asprintf");

1326

return 0;

1327

}

1328

1329

ret = stat(fullname, &st);

1349

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

1330

1350

if(ret == -1){

1331

1351

if(debug){

1332

1352

perror_plus("Could not stat hook");

1356

1376

return 1;

1357

1377

}

1358

1378

1379

__attribute__((nonnull, warn_unused_result))

1359

1380

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1360

1381

mandos_context *mc){

1361

1382

int ret;

1365

1386

1366

1387

while(true){

1367

1388

if(mc->current_server == NULL){

1368

if (debug){

1389

if(debug){

1369

1390

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

1370

1391

" No timeout!\n");

1371

1392

}

1372

1393

ret = avahi_simple_poll_iterate(s, -1);

1373

1394

} else {

1374

if (debug){

1395

if(debug){

1375

1396

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

1376

1397

" it, or wait\n");

1377

1398

}

1394

1415

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

1395

1416

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

1396

1417

1397

if (debug){

1418

if(debug){

1398

1419

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

1399

1420

block_time);

1400

1421

}

1422

1443

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

1423

1444

}

1424

1445

if(ret != 0){

1425

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

1446

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

1426

1447

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

1427

1448

}

1428

1449

}

1430

1451

}

1431

1452

1432

1453

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

1454

__attribute__((warn_unused_result))

1433

1455

error_t raise_privileges(void){

1434

1456

error_t old_errno = errno;

1435

1457

error_t ret_errno = 0;

1442

1464

}

1443

1465

1444

1466

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

1467

__attribute__((warn_unused_result))

1445

1468

error_t raise_privileges_permanently(void){

1446

1469

error_t old_errno = errno;

1447

1470

error_t ret_errno = raise_privileges();

1458

1481

}

1459

1482

1460

1483

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

1484

__attribute__((warn_unused_result))

1461

1485

error_t lower_privileges(void){

1462

1486

error_t old_errno = errno;

1463

1487

error_t ret_errno = 0;

1470

1494

}

1471

1495

1472

1496

/* Lower privileges permanently */

1497

__attribute__((warn_unused_result))

1473

1498

error_t lower_privileges_permanently(void){

1474

1499

error_t old_errno = errno;

1475

1500

error_t ret_errno = 0;

1481

1506

return ret_errno;

1482

1507

}

1483

1508

1484

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

1509

#ifndef O_CLOEXEC

1510

/*

1511

* Based on the example in the GNU LibC manual chapter 13.13 "File

1512

* Descriptor Flags".

1513

| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |

1514

*/

1515

__attribute__((warn_unused_result))

1516

static int set_cloexec_flag(int fd){

1517

int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));

1518

/* If reading the flags failed, return error indication now. */

1519

if(ret < 0){

1520

return ret;

1521

}

1522

/* Store modified flag word in the descriptor. */

1523

return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,

1524

ret | FD_CLOEXEC));

1525

}

1526

#endif /* not O_CLOEXEC */

1527

1528

__attribute__((nonnull))

1529

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

1485

1530

const float delay){

1486

1531

struct dirent **direntries;

1532

if(hookdir_fd == -1){

1533

hookdir_fd = open(hookdir, O_RDONLY |

1534

#ifdef O_CLOEXEC

1535

O_CLOEXEC

1536

#else /* not O_CLOEXEC */

1537

0

1538

#endif /* not O_CLOEXEC */

1539

);

1540

if(hookdir_fd == -1){

1541

if(errno == ENOENT){

1542

if(debug){

1543

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

1544

" found\n", hookdir);

1545

}

1546

} else {

1547

perror_plus("open");

1548

}

1549

return;

1550

}

1551

#ifndef O_CLOEXEC

1552

if(set_cloexec_flag(hookdir_fd) < 0){

1553

perror_plus("set_cloexec_flag");

1554

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

1555

perror_plus("close");

1556

} else {

1557

hookdir_fd = -1;

1558

}

1559

return;

1560

}

1561

#endif /* not O_CLOEXEC */

1562

}

1563

#ifdef __GLIBC__

1564

#if __GLIBC_PREREQ(2, 15)

1565

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

1566

runnable_hook, alphasort);

1567

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

1568

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

1569

alphasort);

1570

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

1571

#else /* not __GLIBC__ */

1572

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

1573

alphasort);

1574

#endif /* not __GLIBC__ */

1575

if(numhooks == -1){

1576

perror_plus("scandir");

1577

return;

1578

}

1487

1579

struct dirent *direntry;

1488

1580

int ret;

1489

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

1490

alphasort);

1491

if(numhooks == -1){

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

perror_plus("scandir");

1581

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

1582

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

1583

direntry = direntries[i];

1584

if(debug){

1585

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

1586

direntry->d_name);

1499

1587

}

1500

} else {

1501

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

1502

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

1503

direntry = direntries[i];

1504

char *fullname = NULL;

1505

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

1506

if(ret < 0){

1588

pid_t hook_pid = fork();

1589

if(hook_pid == 0){

1590

/* Child */

1591

/* Raise privileges */

1592

if(raise_privileges_permanently() != 0){

1593

perror_plus("Failed to raise privileges");

1594

_exit(EX_NOPERM);

1595

}

1596

/* Set group */

1597

errno = 0;

1598

ret = setgid(0);

1599

if(ret == -1){

1600

perror_plus("setgid");

1601

_exit(EX_NOPERM);

1602

}

1603

/* Reset supplementary groups */

1604

errno = 0;

1605

ret = setgroups(0, NULL);

1606

if(ret == -1){

1607

perror_plus("setgroups");

1608

_exit(EX_NOPERM);

1609

}

1610

ret = dup2(devnull, STDIN_FILENO);

1611

if(ret == -1){

1612

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

1613

_exit(EX_OSERR);

1614

}

1615

ret = close(devnull);

1616

if(ret == -1){

1617

perror_plus("close");

1618

_exit(EX_OSERR);

1619

}

1620

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1621

if(ret == -1){

1622

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

1623

_exit(EX_OSERR);

1624

}

1625

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

1626

if(ret == -1){

1627

perror_plus("setenv");

1628

_exit(EX_OSERR);

1629

}

1630

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

1631

if(ret == -1){

1632

perror_plus("setenv");

1633

_exit(EX_OSERR);

1634

}

1635

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

1636

if(ret == -1){

1637

perror_plus("setenv");

1638

_exit(EX_OSERR);

1639

}

1640

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

1641

if(ret == -1){

1642

perror_plus("setenv");

1643

_exit(EX_OSERR);

1644

}

1645

char *delaystring;

1646

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

1647

if(ret == -1){

1507

1648

perror_plus("asprintf");

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

1649

_exit(EX_OSERR);

1650

}

1651

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

1652

if(ret == -1){

1566

1653

free(delaystring);

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

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

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

1654

perror_plus("setenv");

1655

_exit(EX_OSERR);

1656

}

1657

free(delaystring);

1658

if(connect_to != NULL){

1659

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

1660

if(ret == -1){

1661

perror_plus("setenv");

1662

_exit(EX_OSERR);

1663

}

1664

}

1665

if(fexecve(hookdir_fd, (char *const [])

1666

{ direntry->d_name, NULL }, environ) == -1){

1667

perror_plus("fexecve");

1668

_exit(EXIT_FAILURE);

1669

}

1670

} else {

1671

int status;

1672

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

1673

perror_plus("waitpid");

1674

continue;

1675

}

1676

if(WIFEXITED(status)){

1677

if(WEXITSTATUS(status) != 0){

1678

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

1679

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

1680

WEXITSTATUS(status));

1681

continue;

1682

}

1683

} else if(WIFSIGNALED(status)){

1684

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

1685

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

1686

WTERMSIG(status));

1687

continue;

1578

1688

} else {

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

return true;

1689

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

1690

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

1691

continue;

1692

}

1693

}

1694

if(debug){

1695

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

1696

direntry->d_name);

1697

}

1698

}

1699

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

1700

perror_plus("close");

1701

} else {

1702

hookdir_fd = -1;

1703

}

1704

close(devnull);

1615

1705

}

1616

1706

1707

__attribute__((nonnull, warn_unused_result))

1617

1708

error_t bring_up_interface(const char *const interface,

1618

1709

const float delay){

1619

int sd = -1;

1620

1710

error_t old_errno = errno;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

1711

int ret;

1623

1712

struct ifreq network;

1624

1713

unsigned int if_index = if_nametoindex(interface);

1625

1714

if(if_index == 0){

1634

1723

}

1635

1724

1636

1725

if(not interface_is_up(interface)){

1637

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

1726

error_t ret_errno = 0, ioctl_errno = 0;

1727

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

1638

1728

ret_errno = errno;

1639

1729

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

1640

1730

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

1731

errno = old_errno;

1641

1732

return ret_errno;

1642

1733

}

1643

network.ifr_flags |= IFF_UP;

1734

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

1644

1735

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

1736

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

1737

if(sd == -1){

1647

1738

ret_errno = errno;

1648

1739

perror_plus("socket");

1649

1740

errno = old_errno;

1650

1741

return ret_errno;

1651

1742

}

1652

1743

1653

1744

if(quit_now){

1654

close(sd);

1745

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

1746

if(ret == -1){

1747

perror_plus("close");

1748

}

1655

1749

errno = old_errno;

1656

1750

return EINTR;

1657

1751

}

1661

1755

interface);

1662

1756

}

1663

1757

1664

/* Raise priviliges */

1665

raise_privileges();

1758

/* Raise privileges */

1759

ret_errno = raise_privileges();

1760

if(ret_errno != 0){

1761

perror_plus("Failed to raise privileges");

1762

}

1666

1763

1667

1764

#ifdef __linux__

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

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

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

perror_plus("klogctl");

1765

int ret_linux;

1766

bool restore_loglevel = false;

1767

if(ret_errno == 0){

1768

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1769

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

1770

ret_linux = klogctl(8, NULL, 5);

1771

if(ret_linux == -1){

1772

perror_plus("klogctl");

1773

} else {

1774

restore_loglevel = true;

1775

}

1675

1776

}

1676

1777

#endif /* __linux__ */

1677

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

1678

ret_errno = errno;

1778

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

1779

ioctl_errno = errno;

1679

1780

#ifdef __linux__

1680

1781

if(restore_loglevel){

1681

1782

ret_linux = klogctl(7, NULL, 0);

1685

1786

}

1686

1787

#endif /* __linux__ */

1687

1788

1688

/* Lower privileges */

1689

lower_privileges();

1789

/* If raise_privileges() succeeded above */

1790

if(ret_errno == 0){

1791

/* Lower privileges */

1792

ret_errno = lower_privileges();

1793

if(ret_errno != 0){

1794

errno = ret_errno;

1795

perror_plus("Failed to lower privileges");

1796

}

1797

}

1690

1798

1691

1799

/* Close the socket */

1692

1800

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

1695

1803

}

1696

1804

1697

1805

if(ret_setflags == -1){

1698

errno = ret_errno;

1806

errno = ioctl_errno;

1699

1807

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1700

1808

errno = old_errno;

1701

return ret_errno;

1809

return ioctl_errno;

1702

1810

}

1703

1811

} else if(debug){

1704

1812

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

1722

1830

return 0;

1723

1831

}

1724

1832

1833

__attribute__((nonnull, warn_unused_result))

1725

1834

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

1727

1835

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

1730

1836

struct ifreq network;

1731

1837

unsigned int if_index = if_nametoindex(interface);

1732

1838

if(if_index == 0){

1735

1841

return ENXIO;

1736

1842

}

1737

1843

if(interface_is_up(interface)){

1844

error_t ret_errno = 0, ioctl_errno = 0;

1738

1845

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

1739

1846

ret_errno = errno;

1740

1847

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

1741

1848

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

1849

errno = old_errno;

1742

1850

return ret_errno;

1743

1851

}

1744

1852

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

1745

1853

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

1854

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

1855

if(sd == -1){

1748

1856

ret_errno = errno;

1749

1857

perror_plus("socket");

1750

1858

errno = old_errno;

1756

1864

interface);

1757

1865

}

1758

1866

1759

/* Raise priviliges */

1760

raise_privileges();

1761

1762

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

1763

ret_errno = errno;

1764

1765

/* Lower privileges */

1766

lower_privileges();

1867

/* Raise privileges */

1868

ret_errno = raise_privileges();

1869

if(ret_errno != 0){

1870

perror_plus("Failed to raise privileges");

1871

}

1872

1873

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

1874

ioctl_errno = errno;

1875

1876

/* If raise_privileges() succeeded above */

1877

if(ret_errno == 0){

1878

/* Lower privileges */

1879

ret_errno = lower_privileges();

1880

if(ret_errno != 0){

1881

errno = ret_errno;

1882

perror_plus("Failed to lower privileges");

1883

}

1884

}

1767

1885

1768

1886

/* Close the socket */

1769

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

1887

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

1770

1888

if(ret == -1){

1771

1889

perror_plus("close");

1772

1890

}

1773

1891

1774

1892

if(ret_setflags == -1){

1775

errno = ret_errno;

1893

errno = ioctl_errno;

1776

1894

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1777

1895

errno = old_errno;

1778

return ret_errno;

1896

return ioctl_errno;

1779

1897

}

1780

1898

} else if(debug){

1781

1899

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

1789

1907

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

1790

1908

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

1791

1909

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

1792

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

1910

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

1793

1911

.interfaces = NULL, .interfaces_size = 0 };

1794

1912

AvahiSServiceBrowser *sb = NULL;

1795

1913

error_t ret_errno;

1799

1917

int exitcode = EXIT_SUCCESS;

1800

1918

char *interfaces_to_take_down = NULL;

1801

1919

size_t interfaces_to_take_down_size = 0;

1802

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

1803

bool tempdir_created = false;

1920

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

1921

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

1922

char *tempdir = NULL;

1804

1923

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1805

1924

const char *seckey = PATHDIR "/" SECKEY;

1806

1925

const char *pubkey = PATHDIR "/" PUBKEY;

1807

1926

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

1809

1927

1810

1928

bool gnutls_initialized = false;

1811

1929

bool gpgme_initialized = false;

1989

2107

/* Work around Debian bug #633582:

1990

2108

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

1991

2109

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2110

/* Re-raise privileges */

2111

ret_errno = raise_privileges();

2112

if(ret_errno != 0){

2113

errno = ret_errno;

2114

perror_plus("Failed to raise privileges");

2115

} else {

1994

2116

struct stat st;

1995

2117

1996

2118

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

2036

2158

}

2037

2159

2038

2160

/* Lower privileges */

2039

lower_privileges();

2161

ret_errno = lower_privileges();

2162

if(ret_errno != 0){

2163

errno = ret_errno;

2164

perror_plus("Failed to lower privileges");

2165

}

2040

2166

}

2041

2167

}

2042

2168

2066

2192

goto end;

2067

2193

}

2068

2194

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

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

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

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2195

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

2196

}

2197

run_network_hooks("start", interfaces_hooks != NULL ?

2198

interfaces_hooks : "", delay);

2077

2199

}

2078

2200

2079

2201

if(not debug){

2167

2289

ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,

2168

2290

direntries[i]->d_name);

2169

2291

if(ret_errno != 0){

2292

errno = ret_errno;

2170

2293

perror_plus("argz_add");

2171

2294

continue;

2172

2295

}

2206

2329

break;

2207

2330

}

2208

2331

bool interface_was_up = interface_is_up(interface);

2209

ret = bring_up_interface(interface, delay);

2332

errno = bring_up_interface(interface, delay);

2210

2333

if(not interface_was_up){

2211

if(ret != 0){

2212

errno = ret;

2334

if(errno != 0){

2213

2335

perror_plus("Failed to bring up interface");

2214

2336

} else {

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2337

errno = argz_add(&interfaces_to_take_down,

2338

&interfaces_to_take_down_size,

2339

interface);

2340

if(errno != 0){

2341

perror_plus("argz_add");

2342

}

2218

2343

}

2219

2344

}

2220

2345

}

2249

2374

goto end;

2250

2375

}

2251

2376

2252

if(mkdtemp(tempdir) == NULL){

2377

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

2378

tempdir = mkdtemp(run_tempdir);

2379

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

2380

if(debug){

2381

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

2382

run_tempdir, old_tempdir);

2383

}

2384

tempdir = mkdtemp(old_tempdir);

2385

}

2386

if(tempdir == NULL){

2253

2387

perror_plus("mkdtemp");

2254

2388

goto end;

2255

2389

}

2256

tempdir_created = true;

2257

2390

2258

2391

if(quit_now){

2259

2392

goto end;

2334

2467

sleep((unsigned int)retry_interval);

2335

2468

}

2336

2469

2337

if (not quit_now){

2470

if(not quit_now){

2338

2471

exitcode = EXIT_SUCCESS;

2339

2472

}

2340

2473

2395

2528

if(debug){

2396

2529

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

2397

2530

}

2398

2531

2399

2532

ret = avahi_loop_with_timeout(simple_poll,

2400

2533

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

2401

2534

if(debug){

2442

2575

}

2443

2576

}

2444

2577

2445

/* Re-raise priviliges */

2578

/* Re-raise privileges */

2446

2579

{

2447

raise_privileges();

2448

2449

/* Run network hooks */

2450

run_network_hooks("stop", interfaces_hooks != NULL ?

2451

interfaces_hooks : "", delay);

2452

2453

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

2454

{

2455

char *interface = NULL;

2456

while((interface=argz_next(interfaces_to_take_down,

2457

interfaces_to_take_down_size,

2458

interface))){

2459

ret_errno = take_down_interface(interface);

2460

if(ret_errno != 0){

2461

errno = ret_errno;

2462

perror_plus("Failed to take down interface");

2463

}

2464

}

2465

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

2466

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

2467

" down\n");

2468

}

2469

}

2470

2471

lower_privileges_permanently();

2580

ret_errno = raise_privileges();

2581

if(ret_errno != 0){

2582

perror_plus("Failed to raise privileges");

2583

} else {

2584

2585

/* Run network hooks */

2586

run_network_hooks("stop", interfaces_hooks != NULL ?

2587

interfaces_hooks : "", delay);

2588

2589

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

2590

{

2591

char *interface = NULL;

2592

while((interface=argz_next(interfaces_to_take_down,

2593

interfaces_to_take_down_size,

2594

interface))){

2595

ret_errno = take_down_interface(interface);

2596

if(ret_errno != 0){

2597

errno = ret_errno;

2598

perror_plus("Failed to take down interface");

2599

}

2600

}

2601

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

2602

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

2603

" down\n");

2604

}

2605

}

2606

}

2607

2608

ret_errno = lower_privileges_permanently();

2609

if(ret_errno != 0){

2610

perror_plus("Failed to lower privileges permanently");

2611

}

2472

2612

}

2473

2613

2474

2614

free(interfaces_to_take_down);

2475

2615

free(interfaces_hooks);

2476

2616

2477

2617

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

2478

if(tempdir_created){

2618

if(tempdir != NULL){

2479

2619

struct dirent **direntries = NULL;

2480

2620

struct dirent *direntry = NULL;

2481

2621

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

2482

2622

alphasort);

2483

if (numentries > 0){

2623

if(numentries > 0){

2484

2624

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

2485

2625

direntry = direntries[i];

2486

2626

char *fullname = NULL;

2498

2638

free(fullname);

2499

2639

}

2500

2640

}

2501

2641

2502

2642

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

2503

2643

free(direntries);

2504

if (numentries == -1){

2644

if(numentries == -1){

2505

2645

perror_plus("scandir");

2506

2646

}

2507

2647

ret = rmdir(tempdir);