/mandos/trunk : revision 706

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){

201

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

202

if(buffer == NULL){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

203

213

return 0;

204

214

}

215

*buffer = new_buf;

205

216

buffer_capacity += BUFFER_SIZE;

206

217

}

207

218

return buffer_capacity;

208

219

}

209

220

210

221

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

222

__attribute__((nonnull, warn_unused_result))

211

223

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

212

224

int af, server **current_server){

213

225

int ret;

224

236

perror_plus("strdup");

225

237

return false;

226

238

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

227

244

/* Special case of first server */

228

245

if(*current_server == NULL){

229

246

new_server->next = new_server;

230

247

new_server->prev = new_server;

231

248

*current_server = new_server;

232

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

233

249

} else {

250

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

234

251

new_server->next = *current_server;

235

252

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

236

253

new_server->prev->next = new_server;

237

254

(*current_server)->prev = new_server;

238

255

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

244

256

return true;

245

257

}

246

258

247

259

/*

248

260

* Initialize GPGME.

249

261

*/

250

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

251

const char *tempdir, mandos_context *mc){

262

__attribute__((nonnull, warn_unused_result))

263

static bool init_gpgme(const char * const seckey,

264

const char * const pubkey,

265

const char * const tempdir,

266

mandos_context *mc){

252

267

gpgme_error_t rc;

253

268

gpgme_engine_info_t engine_info;

254

269

255

270

/*

256

271

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

257

272

*/

258

bool import_key(const char *filename){

273

bool import_key(const char * const filename){

259

274

int ret;

260

275

int fd;

261

276

gpgme_data_t pgp_data;

342

357

* Decrypt OpenPGP data.

343

358

* Returns -1 on error

344

359

*/

360

__attribute__((nonnull, warn_unused_result))

345

361

static ssize_t pgp_packet_decrypt(const char *cryptotext,

346

362

size_t crypto_size,

347

363

char **plaintext,

467

483

return plaintext_length;

468

484

}

469

485

470

static const char * safer_gnutls_strerror(int value){

486

__attribute__((warn_unused_result))

487

static const char *safer_gnutls_strerror(int value){

471

488

const char *ret = gnutls_strerror(value);

472

489

if(ret == NULL)

473

490

ret = "(unknown)";

475

492

}

476

493

477

494

/* GnuTLS log function callback */

495

__attribute__((nonnull))

478

496

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

479

497

const char* string){

480

498

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

481

499

}

482

500

501

__attribute__((nonnull, warn_unused_result))

483

502

static int init_gnutls_global(const char *pubkeyfilename,

484

503

const char *seckeyfilename,

485

504

mandos_context *mc){

559

578

return -1;

560

579

}

561

580

581

__attribute__((nonnull, warn_unused_result))

562

582

static int init_gnutls_session(gnutls_session_t *session,

563

583

mandos_context *mc){

564

584

int ret;

621

641

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

622

642

623

643

/* Called when a Mandos server is found */

644

__attribute__((nonnull, warn_unused_result))

624

645

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

625

646

AvahiIfIndex if_index,

626

647

int af, mandos_context *mc){

627

648

int ret, tcp_sd = -1;

628

649

ssize_t sret;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

650

struct sockaddr_storage to;

633

651

char *buffer = NULL;

634

652

char *decrypted_buffer = NULL;

635

653

size_t buffer_length = 0;

716

734

717

735

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

718

736

if(af == AF_INET6){

719

to.in6.sin6_family = (sa_family_t)af;

720

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

737

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

738

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

721

739

} else { /* IPv4 */

722

to.in.sin_family = (sa_family_t)af;

723

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

740

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

741

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

724

742

}

725

743

if(ret < 0 ){

726

744

int e = errno;

735

753

goto mandos_end;

736

754

}

737

755

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*/

756

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

757

if(IN6_IS_ADDR_LINKLOCAL

758

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

742

759

if(if_index == AVAHI_IF_UNSPEC){

743

760

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

744

761

" incomplete without a network interface\n");

746

763

goto mandos_end;

747

764

}

748

765

/* Set the network interface number as scope */

749

to.in6.sin6_scope_id = (uint32_t)if_index;

766

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

750

767

}

751

768

} else {

752

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

753

-Wconversion and

754

-Wunreachable-code */

769

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

755

770

}

756

771

757

772

if(quit_now){

774

789

}

775

790

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

776

791

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

777

const char *pcret;

778

792

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

793

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

794

sizeof(struct sockaddr_in6),

795

addrstr, sizeof(addrstr), NULL, 0,

796

NI_NUMERICHOST);

781

797

} else {

782

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

783

sizeof(addrstr));

798

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

799

sizeof(struct sockaddr_in),

800

addrstr, sizeof(addrstr), NULL, 0,

801

NI_NUMERICHOST);

784

802

}

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

}

803

if(ret == EAI_SYSTEM){

804

perror_plus("getnameinfo");

805

} else if(ret != 0) {

806

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

807

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

808

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

791

809

}

792

810

}

793

811

797

815

}

798

816

799

817

if(af == AF_INET6){

800

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

818

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

819

sizeof(struct sockaddr_in6));

801

820

} else {

802

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

821

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

822

sizeof(struct sockaddr_in));

803

823

}

804

824

if(ret < 0){

805

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

825

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

806

826

int e = errno;

807

827

perror_plus("connect");

808

828

errno = e;

1023

1043

return retval;

1024

1044

}

1025

1045

1046

__attribute__((nonnull))

1026

1047

static void resolve_callback(AvahiSServiceResolver *r,

1027

1048

AvahiIfIndex interface,

1028

1049

AvahiProtocol proto,

1036

1057

AVAHI_GCC_UNUSED AvahiStringList *txt,

1037

1058

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1038

1059

flags,

1039

void* mc){

1060

void *mc){

1040

1061

if(r == NULL){

1041

1062

return;

1042

1063

}

1095

1116

const char *domain,

1096

1117

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1097

1118

flags,

1098

void* mc){

1119

void *mc){

1099

1120

if(b == NULL){

1100

1121

return;

1101

1122

}

1161

1182

errno = old_errno;

1162

1183

}

1163

1184

1185

__attribute__((nonnull, warn_unused_result))

1164

1186

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

1165

1187

int ret;

1166

1188

error_t ret_errno;

1185

1207

return true;

1186

1208

}

1187

1209

1210

__attribute__((nonnull, warn_unused_result))

1188

1211

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

1189

1212

1190

1213

/* Reject the loopback device */

1232

1255

* corresponds to an acceptable network device.

1233

1256

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

1234

1257

*/

1258

__attribute__((nonnull, warn_unused_result))

1235

1259

int good_interface(const struct dirent *if_entry){

1236

1260

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

1237

1261

return 0;

1255

1279

/*

1256

1280

* This function determines if a network interface is up.

1257

1281

*/

1282

__attribute__((nonnull, warn_unused_result))

1258

1283

bool interface_is_up(const char *interface){

1259

1284

struct ifreq ifr;

1260

1285

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

1271

1296

/*

1272

1297

* This function determines if a network interface is running

1273

1298

*/

1299

__attribute__((nonnull, warn_unused_result))

1274

1300

bool interface_is_running(const char *interface){

1275

1301

struct ifreq ifr;

1276

1302

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

1284

1310

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

1285

1311

}

1286

1312

1313

__attribute__((nonnull, pure, warn_unused_result))

1287

1314

int notdotentries(const struct dirent *direntry){

1288

1315

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

1289

1316

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

1296

1323

}

1297

1324

1298

1325

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

1326

__attribute__((nonnull, warn_unused_result))

1299

1327

int runnable_hook(const struct dirent *direntry){

1300

1328

int ret;

1301

1329

size_t sret;

1309

1337

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

1310

1338

"abcdefghijklmnopqrstuvwxyz"

1311

1339

"0123456789"

1312

"_-");

1340

"_.-");

1313

1341

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

1314

1342

/* Contains non-allowed characters */

1315

1343

if(debug){

1319

1347

return 0;

1320

1348

}

1321

1349

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);

1350

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

1330

1351

if(ret == -1){

1331

1352

if(debug){

1332

1353

perror_plus("Could not stat hook");

1356

1377

return 1;

1357

1378

}

1358

1379

1380

__attribute__((nonnull, warn_unused_result))

1359

1381

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1360

1382

mandos_context *mc){

1361

1383

int ret;

1365

1387

1366

1388

while(true){

1367

1389

if(mc->current_server == NULL){

1368

if (debug){

1390

if(debug){

1369

1391

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

1370

1392

" No timeout!\n");

1371

1393

}

1372

1394

ret = avahi_simple_poll_iterate(s, -1);

1373

1395

} else {

1374

if (debug){

1396

if(debug){

1375

1397

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

1376

1398

" it, or wait\n");

1377

1399

}

1394

1416

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

1395

1417

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

1396

1418

1397

if (debug){

1419

if(debug){

1398

1420

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

1399

1421

block_time);

1400

1422

}

1422

1444

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

1423

1445

}

1424

1446

if(ret != 0){

1425

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

1447

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

1426

1448

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

1427

1449

}

1428

1450

}

1430

1452

}

1431

1453

1432

1454

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

1455

__attribute__((warn_unused_result))

1433

1456

error_t raise_privileges(void){

1434

1457

error_t old_errno = errno;

1435

1458

error_t ret_errno = 0;

1436

1459

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

1437

1460

ret_errno = errno;

1438

perror_plus("seteuid");

1439

1461

}

1440

1462

errno = old_errno;

1441

1463

return ret_errno;

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();

1451

1474

}

1452

1475

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

1453

1476

ret_errno = errno;

1454

perror_plus("seteuid");

1455

1477

}

1456

1478

errno = old_errno;

1457

1479

return ret_errno;

1458

1480

}

1459

1481

1460

1482

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

1483

__attribute__((warn_unused_result))

1461

1484

error_t lower_privileges(void){

1462

1485

error_t old_errno = errno;

1463

1486

error_t ret_errno = 0;

1464

1487

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

1465

1488

ret_errno = errno;

1466

perror_plus("seteuid");

1467

1489

}

1468

1490

errno = old_errno;

1469

1491

return ret_errno;

1470

1492

}

1471

1493

1472

1494

/* Lower privileges permanently */

1495

__attribute__((warn_unused_result))

1473

1496

error_t lower_privileges_permanently(void){

1474

1497

error_t old_errno = errno;

1475

1498

error_t ret_errno = 0;

1476

1499

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

1477

1500

ret_errno = errno;

1478

perror_plus("setuid");

1479

1501

}

1480

1502

errno = old_errno;

1481

1503

return ret_errno;

1482

1504

}

1483

1505

1484

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

1506

__attribute__((nonnull))

1507

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

1485

1508

const float delay){

1486

struct dirent **direntries;

1509

struct dirent **direntries = NULL;

1510

if(hookdir_fd == -1){

1511

hookdir_fd = open(hookdir, O_RDONLY);

1512

if(hookdir_fd == -1){

1513

if(errno == ENOENT){

1514

if(debug){

1515

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

1516

" found\n", hookdir);

1517

}

1518

} else {

1519

perror_plus("open");

1520

}

1521

return;

1522

}

1523

}

1524

#ifdef __GLIBC__

1525

#if __GLIBC_PREREQ(2, 15)

1526

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

1527

runnable_hook, alphasort);

1528

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

1529

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

1530

alphasort);

1531

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

1532

#else /* not __GLIBC__ */

1533

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

1534

alphasort);

1535

#endif /* not __GLIBC__ */

1536

if(numhooks == -1){

1537

perror_plus("scandir");

1538

return;

1539

}

1487

1540

struct dirent *direntry;

1488

1541

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");

1542

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

1543

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

1544

direntry = direntries[i];

1545

if(debug){

1546

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

1547

direntry->d_name);

1499

1548

}

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){

1549

pid_t hook_pid = fork();

1550

if(hook_pid == 0){

1551

/* Child */

1552

/* Raise privileges */

1553

errno = raise_privileges_permanently();

1554

if(errno != 0){

1555

perror_plus("Failed to raise privileges");

1556

_exit(EX_NOPERM);

1557

}

1558

/* Set group */

1559

errno = 0;

1560

ret = setgid(0);

1561

if(ret == -1){

1562

perror_plus("setgid");

1563

_exit(EX_NOPERM);

1564

}

1565

/* Reset supplementary groups */

1566

errno = 0;

1567

ret = setgroups(0, NULL);

1568

if(ret == -1){

1569

perror_plus("setgroups");

1570

_exit(EX_NOPERM);

1571

}

1572

ret = dup2(devnull, STDIN_FILENO);

1573

if(ret == -1){

1574

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

1575

_exit(EX_OSERR);

1576

}

1577

ret = close(devnull);

1578

if(ret == -1){

1579

perror_plus("close");

1580

_exit(EX_OSERR);

1581

}

1582

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1583

if(ret == -1){

1584

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

1585

_exit(EX_OSERR);

1586

}

1587

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

1588

if(ret == -1){

1589

perror_plus("setenv");

1590

_exit(EX_OSERR);

1591

}

1592

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

1593

if(ret == -1){

1594

perror_plus("setenv");

1595

_exit(EX_OSERR);

1596

}

1597

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

1598

if(ret == -1){

1599

perror_plus("setenv");

1600

_exit(EX_OSERR);

1601

}

1602

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

1603

if(ret == -1){

1604

perror_plus("setenv");

1605

_exit(EX_OSERR);

1606

}

1607

char *delaystring;

1608

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

1609

if(ret == -1){

1507

1610

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

}

1611

_exit(EX_OSERR);

1612

}

1613

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

1614

if(ret == -1){

1566

1615

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

}

1616

perror_plus("setenv");

1617

_exit(EX_OSERR);

1618

}

1619

free(delaystring);

1620

if(connect_to != NULL){

1621

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

1622

if(ret == -1){

1623

perror_plus("setenv");

1624

_exit(EX_OSERR);

1625

}

1626

}

1627

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

1628

if(hook_fd == -1){

1629

perror_plus("openat");

1630

_exit(EXIT_FAILURE);

1631

}

1632

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

1633

perror_plus("close");

1634

_exit(EXIT_FAILURE);

1635

}

1636

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

1637

environ) == -1){

1638

perror_plus("fexecve");

1639

_exit(EXIT_FAILURE);

1640

}

1641

} else {

1642

int status;

1643

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

1644

perror_plus("waitpid");

1645

continue;

1646

}

1647

if(WIFEXITED(status)){

1648

if(WEXITSTATUS(status) != 0){

1649

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

1650

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

1651

WEXITSTATUS(status));

1652

continue;

1653

}

1654

} else if(WIFSIGNALED(status)){

1655

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

1656

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

1657

WTERMSIG(status));

1658

continue;

1578

1659

} 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;

1660

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

1661

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

1662

continue;

1663

}

1664

}

1665

if(debug){

1666

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

1667

direntry->d_name);

1668

}

1669

}

1670

free(direntries);

1671

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

1672

perror_plus("close");

1673

} else {

1674

hookdir_fd = -1;

1675

}

1676

close(devnull);

1615

1677

}

1616

1678

1679

__attribute__((nonnull, warn_unused_result))

1617

1680

error_t bring_up_interface(const char *const interface,

1618

1681

const float delay){

1619

int sd = -1;

1620

1682

error_t old_errno = errno;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

1683

int ret;

1623

1684

struct ifreq network;

1624

1685

unsigned int if_index = if_nametoindex(interface);

1625

1686

if(if_index == 0){

1634

1695

}

1635

1696

1636

1697

if(not interface_is_up(interface)){

1637

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

1698

error_t ret_errno = 0, ioctl_errno = 0;

1699

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

1638

1700

ret_errno = errno;

1639

1701

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

1640

1702

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

1703

errno = old_errno;

1641

1704

return ret_errno;

1642

1705

}

1643

network.ifr_flags |= IFF_UP;

1706

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

1644

1707

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

1708

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

1709

if(sd == -1){

1647

1710

ret_errno = errno;

1648

1711

perror_plus("socket");

1649

1712

errno = old_errno;

1650

1713

return ret_errno;

1651

1714

}

1652

1715

1653

1716

if(quit_now){

1654

close(sd);

1717

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

1718

if(ret == -1){

1719

perror_plus("close");

1720

}

1655

1721

errno = old_errno;

1656

1722

return EINTR;

1657

1723

}

1661

1727

interface);

1662

1728

}

1663

1729

1664

/* Raise priviliges */

1665

raise_privileges();

1730

/* Raise privileges */

1731

ret_errno = raise_privileges();

1732

if(ret_errno != 0){

1733

errno = ret_errno;

1734

perror_plus("Failed to raise privileges");

1735

}

1666

1736

1667

1737

#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");

1738

int ret_linux;

1739

bool restore_loglevel = false;

1740

if(ret_errno == 0){

1741

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1742

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

1743

ret_linux = klogctl(8, NULL, 5);

1744

if(ret_linux == -1){

1745

perror_plus("klogctl");

1746

} else {

1747

restore_loglevel = true;

1748

}

1675

1749

}

1676

1750

#endif /* __linux__ */

1677

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

1678

ret_errno = errno;

1751

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

1752

ioctl_errno = errno;

1679

1753

#ifdef __linux__

1680

1754

if(restore_loglevel){

1681

1755

ret_linux = klogctl(7, NULL, 0);

1685

1759

}

1686

1760

#endif /* __linux__ */

1687

1761

1688

/* Lower privileges */

1689

lower_privileges();

1762

/* If raise_privileges() succeeded above */

1763

if(ret_errno == 0){

1764

/* Lower privileges */

1765

ret_errno = lower_privileges();

1766

if(ret_errno != 0){

1767

errno = ret_errno;

1768

perror_plus("Failed to lower privileges");

1769

}

1770

}

1690

1771

1691

1772

/* Close the socket */

1692

1773

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

1695

1776

}

1696

1777

1697

1778

if(ret_setflags == -1){

1698

errno = ret_errno;

1779

errno = ioctl_errno;

1699

1780

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1700

1781

errno = old_errno;

1701

return ret_errno;

1782

return ioctl_errno;

1702

1783

}

1703

1784

} else if(debug){

1704

1785

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

1722

1803

return 0;

1723

1804

}

1724

1805

1806

__attribute__((nonnull, warn_unused_result))

1725

1807

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

1727

1808

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

1730

1809

struct ifreq network;

1731

1810

unsigned int if_index = if_nametoindex(interface);

1732

1811

if(if_index == 0){

1735

1814

return ENXIO;

1736

1815

}

1737

1816

if(interface_is_up(interface)){

1817

error_t ret_errno = 0, ioctl_errno = 0;

1738

1818

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

1739

1819

ret_errno = errno;

1740

1820

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

1741

1821

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

1822

errno = old_errno;

1742

1823

return ret_errno;

1743

1824

}

1744

1825

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

1745

1826

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

1827

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

1828

if(sd == -1){

1748

1829

ret_errno = errno;

1749

1830

perror_plus("socket");

1750

1831

errno = old_errno;

1756

1837

interface);

1757

1838

}

1758

1839

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();

1840

/* Raise privileges */

1841

ret_errno = raise_privileges();

1842

if(ret_errno != 0){

1843

errno = ret_errno;

1844

perror_plus("Failed to raise privileges");

1845

}

1846

1847

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

1848

ioctl_errno = errno;

1849

1850

/* If raise_privileges() succeeded above */

1851

if(ret_errno == 0){

1852

/* Lower privileges */

1853

ret_errno = lower_privileges();

1854

if(ret_errno != 0){

1855

errno = ret_errno;

1856

perror_plus("Failed to lower privileges");

1857

}

1858

}

1767

1859

1768

1860

/* Close the socket */

1769

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

1861

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

1770

1862

if(ret == -1){

1771

1863

perror_plus("close");

1772

1864

}

1773

1865

1774

1866

if(ret_setflags == -1){

1775

errno = ret_errno;

1867

errno = ioctl_errno;

1776

1868

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1777

1869

errno = old_errno;

1778

return ret_errno;

1870

return ioctl_errno;

1779

1871

}

1780

1872

} else if(debug){

1781

1873

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

1789

1881

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

1790

1882

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

1791

1883

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

1792

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

1884

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

1793

1885

.interfaces = NULL, .interfaces_size = 0 };

1794

1886

AvahiSServiceBrowser *sb = NULL;

1795

1887

error_t ret_errno;

1799

1891

int exitcode = EXIT_SUCCESS;

1800

1892

char *interfaces_to_take_down = NULL;

1801

1893

size_t interfaces_to_take_down_size = 0;

1802

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

1803

bool tempdir_created = false;

1894

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

1895

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

1896

char *tempdir = NULL;

1804

1897

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1805

1898

const char *seckey = PATHDIR "/" SECKEY;

1806

1899

const char *pubkey = PATHDIR "/" PUBKEY;

1807

1900

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

1809

1901

1810

1902

bool gnutls_initialized = false;

1811

1903

bool gpgme_initialized = false;

1989

2081

/* Work around Debian bug #633582:

1990

2082

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

1991

2083

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2084

/* Re-raise privileges */

2085

ret_errno = raise_privileges();

2086

if(ret_errno != 0){

2087

errno = ret_errno;

2088

perror_plus("Failed to raise privileges");

2089

} else {

1994

2090

struct stat st;

1995

2091

1996

2092

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

2036

2132

}

2037

2133

2038

2134

/* Lower privileges */

2039

lower_privileges();

2135

ret_errno = lower_privileges();

2136

if(ret_errno != 0){

2137

errno = ret_errno;

2138

perror_plus("Failed to lower privileges");

2139

}

2040

2140

}

2041

2141

}

2042

2142

2066

2166

goto end;

2067

2167

}

2068

2168

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

}

2169

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

2170

}

2171

run_network_hooks("start", interfaces_hooks != NULL ?

2172

interfaces_hooks : "", delay);

2077

2173

}

2078

2174

2079

2175

if(not debug){

2157

2253

2158

2254

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

2159

2255

if(mc.interfaces == NULL){

2160

struct dirent **direntries;

2256

struct dirent **direntries = NULL;

2161

2257

/* Look for any good interfaces */

2162

2258

ret = scandir(sys_class_net, &direntries, good_interface,

2163

2259

alphasort);

2167

2263

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

2168

2264

direntries[i]->d_name);

2169

2265

if(ret_errno != 0){

2266

errno = ret_errno;

2170

2267

perror_plus("argz_add");

2171

2268

continue;

2172

2269

}

2177

2274

}

2178

2275

free(direntries);

2179

2276

} else {

2180

free(direntries);

2277

if(ret == 0){

2278

free(direntries);

2279

}

2181

2280

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

2182

2281

exitcode = EXIT_FAILURE;

2183

2282

goto end;

2206

2305

break;

2207

2306

}

2208

2307

bool interface_was_up = interface_is_up(interface);

2209

ret = bring_up_interface(interface, delay);

2308

errno = bring_up_interface(interface, delay);

2210

2309

if(not interface_was_up){

2211

if(ret != 0){

2212

errno = ret;

2310

if(errno != 0){

2213

2311

perror_plus("Failed to bring up interface");

2214

2312

} else {

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2313

errno = argz_add(&interfaces_to_take_down,

2314

&interfaces_to_take_down_size,

2315

interface);

2316

if(errno != 0){

2317

perror_plus("argz_add");

2318

}

2218

2319

}

2219

2320

}

2220

2321

}

2249

2350

goto end;

2250

2351

}

2251

2352

2252

if(mkdtemp(tempdir) == NULL){

2353

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

2354

tempdir = mkdtemp(run_tempdir);

2355

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

2356

if(debug){

2357

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

2358

run_tempdir, old_tempdir);

2359

}

2360

tempdir = mkdtemp(old_tempdir);

2361

}

2362

if(tempdir == NULL){

2253

2363

perror_plus("mkdtemp");

2254

2364

goto end;

2255

2365

}

2256

tempdir_created = true;

2257

2366

2258

2367

if(quit_now){

2259

2368

goto end;

2334

2443

sleep((unsigned int)retry_interval);

2335

2444

}

2336

2445

2337

if (not quit_now){

2446

if(not quit_now){

2338

2447

exitcode = EXIT_SUCCESS;

2339

2448

}

2340

2449

2395

2504

if(debug){

2396

2505

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

2397

2506

}

2398

2507

2399

2508

ret = avahi_loop_with_timeout(simple_poll,

2400

2509

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

2401

2510

if(debug){

2442

2551

}

2443

2552

}

2444

2553

2445

/* Re-raise priviliges */

2554

/* Re-raise privileges */

2446

2555

{

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();

2556

ret_errno = raise_privileges();

2557

if(ret_errno != 0){

2558

errno = ret_errno;

2559

perror_plus("Failed to raise privileges");

2560

} else {

2561

2562

/* Run network hooks */

2563

run_network_hooks("stop", interfaces_hooks != NULL ?

2564

interfaces_hooks : "", delay);

2565

2566

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

2567

{

2568

char *interface = NULL;

2569

while((interface=argz_next(interfaces_to_take_down,

2570

interfaces_to_take_down_size,

2571

interface))){

2572

ret_errno = take_down_interface(interface);

2573

if(ret_errno != 0){

2574

errno = ret_errno;

2575

perror_plus("Failed to take down interface");

2576

}

2577

}

2578

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

2579

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

2580

" down\n");

2581

}

2582

}

2583

}

2584

2585

ret_errno = lower_privileges_permanently();

2586

if(ret_errno != 0){

2587

errno = ret_errno;

2588

perror_plus("Failed to lower privileges permanently");

2589

}

2472

2590

}

2473

2591

2474

2592

free(interfaces_to_take_down);

2475

2593

free(interfaces_hooks);

2476

2594

2477

2595

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

2478

if(tempdir_created){

2596

if(tempdir != NULL){

2479

2597

struct dirent **direntries = NULL;

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

2484

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

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

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

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

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

2496

strerror(errno));

2497

}

2498

free(fullname);

2598

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

2599

O_NOFOLLOW));

2600

if(tempdir_fd == -1){

2601

perror_plus("open");

2602

} else {

2603

#ifdef __GLIBC__

2604

#if __GLIBC_PREREQ(2, 15)

2605

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

2606

notdotentries, alphasort);

2607

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

2608

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

2609

alphasort);

2610

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

2611

#else /* not __GLIBC__ */

2612

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

2613

alphasort);

2614

#endif /* not __GLIBC__ */

2615

if(numentries >= 0){

2616

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

2617

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

2618

if(ret == -1){

2619

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

2620

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

2621

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

2622

}

2623

}

2624

2625

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

2626

free(direntries);

2627

if(numentries == -1){

2628

perror_plus("scandir");

2629

}

2630

ret = rmdir(tempdir);

2631

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

2632

perror_plus("rmdir");

2633

}

2499

2634

}

2500

}

2501

2502

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

2503

free(direntries);

2504

if (numentries == -1){

2505

perror_plus("scandir");

2506

}

2507

ret = rmdir(tempdir);

2508

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

2509

perror_plus("rmdir");

2635

TEMP_FAILURE_RETRY(close(tempdir_fd));

2510

2636

}

2511

2637

}

2512

2638