/mandos/release : revision 237.7.256

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

#ifdef __GNUC__

740

#pragma GCC diagnostic push

741

#pragma GCC diagnostic ignored "-Wstrict-aliasing"

742

#endif

743

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

744

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

745

#ifdef __GNUC__

746

#pragma GCC diagnostic pop

747

#endif

756

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

757

if(IN6_IS_ADDR_LINKLOCAL

758

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

748

759

if(if_index == AVAHI_IF_UNSPEC){

749

760

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

750

761

" incomplete without a network interface\n");

752

763

goto mandos_end;

753

764

}

754

765

/* Set the network interface number as scope */

755

to.in6.sin6_scope_id = (uint32_t)if_index;

766

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

756

767

}

757

768

} else {

758

to.in.sin_port = htons(port);

769

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

759

770

}

760

771

761

772

if(quit_now){

778

789

}

779

790

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

780

791

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

781

const char *pcret;

782

792

if(af == AF_INET6){

783

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

784

sizeof(addrstr));

793

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

794

sizeof(struct sockaddr_in6),

795

addrstr, sizeof(addrstr), NULL, 0,

796

NI_NUMERICHOST);

785

797

} else {

786

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

787

sizeof(addrstr));

798

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

799

sizeof(struct sockaddr_in),

800

addrstr, sizeof(addrstr), NULL, 0,

801

NI_NUMERICHOST);

788

802

}

789

if(pcret == NULL){

790

perror_plus("inet_ntop");

791

} else {

792

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

793

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

794

}

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);

795

809

}

796

810

}

797

811

801

815

}

802

816

803

817

if(af == AF_INET6){

804

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

818

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

819

sizeof(struct sockaddr_in6));

805

820

} else {

806

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

821

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

822

sizeof(struct sockaddr_in));

807

823

}

808

824

if(ret < 0){

809

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

825

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

810

826

int e = errno;

811

827

perror_plus("connect");

812

828

errno = e;

1027

1043

return retval;

1028

1044

}

1029

1045

1046

__attribute__((nonnull))

1030

1047

static void resolve_callback(AvahiSServiceResolver *r,

1031

1048

AvahiIfIndex interface,

1032

1049

AvahiProtocol proto,

1040

1057

AVAHI_GCC_UNUSED AvahiStringList *txt,

1041

1058

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1042

1059

flags,

1043

void* mc){

1060

void *mc){

1044

1061

if(r == NULL){

1045

1062

return;

1046

1063

}

1099

1116

const char *domain,

1100

1117

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1101

1118

flags,

1102

void* mc){

1119

void *mc){

1103

1120

if(b == NULL){

1104

1121

return;

1105

1122

}

1165

1182

errno = old_errno;

1166

1183

}

1167

1184

1185

__attribute__((nonnull, warn_unused_result))

1168

1186

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

1169

1187

int ret;

1170

1188

error_t ret_errno;

1189

1207

return true;

1190

1208

}

1191

1209

1210

__attribute__((nonnull, warn_unused_result))

1192

1211

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

1193

1212

1194

1213

/* Reject the loopback device */

1236

1255

* corresponds to an acceptable network device.

1237

1256

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

1238

1257

*/

1258

__attribute__((nonnull, warn_unused_result))

1239

1259

int good_interface(const struct dirent *if_entry){

1240

1260

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

1241

1261

return 0;

1259

1279

/*

1260

1280

* This function determines if a network interface is up.

1261

1281

*/

1282

__attribute__((nonnull, warn_unused_result))

1262

1283

bool interface_is_up(const char *interface){

1263

1284

struct ifreq ifr;

1264

1285

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

1275

1296

/*

1276

1297

* This function determines if a network interface is running

1277

1298

*/

1299

__attribute__((nonnull, warn_unused_result))

1278

1300

bool interface_is_running(const char *interface){

1279

1301

struct ifreq ifr;

1280

1302

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

1288

1310

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

1289

1311

}

1290

1312

1313

__attribute__((nonnull, pure, warn_unused_result))

1291

1314

int notdotentries(const struct dirent *direntry){

1292

1315

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

1293

1316

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

1300

1323

}

1301

1324

1302

1325

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

1326

__attribute__((nonnull, warn_unused_result))

1303

1327

int runnable_hook(const struct dirent *direntry){

1304

1328

int ret;

1305

1329

size_t sret;

1313

1337

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

1314

1338

"abcdefghijklmnopqrstuvwxyz"

1315

1339

"0123456789"

1316

"_-");

1340

"_.-");

1317

1341

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

1318

1342

/* Contains non-allowed characters */

1319

1343

if(debug){

1323

1347

return 0;

1324

1348

}

1325

1349

1326

char *fullname = NULL;

1327

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

1328

if(ret < 0){

1329

perror_plus("asprintf");

1330

return 0;

1331

}

1332

1333

ret = stat(fullname, &st);

1350

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

1334

1351

if(ret == -1){

1335

1352

if(debug){

1336

1353

perror_plus("Could not stat hook");

1360

1377

return 1;

1361

1378

}

1362

1379

1380

__attribute__((nonnull, warn_unused_result))

1363

1381

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1364

1382

mandos_context *mc){

1365

1383

int ret;

1369

1387

1370

1388

while(true){

1371

1389

if(mc->current_server == NULL){

1372

if (debug){

1390

if(debug){

1373

1391

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

1374

1392

" No timeout!\n");

1375

1393

}

1376

1394

ret = avahi_simple_poll_iterate(s, -1);

1377

1395

} else {

1378

if (debug){

1396

if(debug){

1379

1397

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

1380

1398

" it, or wait\n");

1381

1399

}

1398

1416

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

1399

1417

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

1400

1418

1401

if (debug){

1419

if(debug){

1402

1420

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

1403

1421

block_time);

1404

1422

}

1426

1444

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

1427

1445

}

1428

1446

if(ret != 0){

1429

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

1447

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

1430

1448

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

1431

1449

}

1432

1450

}

1434

1452

}

1435

1453

1436

1454

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

1455

__attribute__((warn_unused_result))

1437

1456

error_t raise_privileges(void){

1438

1457

error_t old_errno = errno;

1439

1458

error_t ret_errno = 0;

1440

1459

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

1441

1460

ret_errno = errno;

1442

perror_plus("seteuid");

1443

1461

}

1444

1462

errno = old_errno;

1445

1463

return ret_errno;

1446

1464

}

1447

1465

1448

1466

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

1467

__attribute__((warn_unused_result))

1449

1468

error_t raise_privileges_permanently(void){

1450

1469

error_t old_errno = errno;

1451

1470

error_t ret_errno = raise_privileges();

1455

1474

}

1456

1475

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

1457

1476

ret_errno = errno;

1458

perror_plus("seteuid");

1459

1477

}

1460

1478

errno = old_errno;

1461

1479

return ret_errno;

1462

1480

}

1463

1481

1464

1482

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

1483

__attribute__((warn_unused_result))

1465

1484

error_t lower_privileges(void){

1466

1485

error_t old_errno = errno;

1467

1486

error_t ret_errno = 0;

1468

1487

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

1469

1488

ret_errno = errno;

1470

perror_plus("seteuid");

1471

1489

}

1472

1490

errno = old_errno;

1473

1491

return ret_errno;

1474

1492

}

1475

1493

1476

1494

/* Lower privileges permanently */

1495

__attribute__((warn_unused_result))

1477

1496

error_t lower_privileges_permanently(void){

1478

1497

error_t old_errno = errno;

1479

1498

error_t ret_errno = 0;

1480

1499

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

1481

1500

ret_errno = errno;

1482

perror_plus("setuid");

1483

1501

}

1484

1502

errno = old_errno;

1485

1503

return ret_errno;

1486

1504

}

1487

1505

1488

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

1506

__attribute__((nonnull))

1507

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

1489

1508

const float delay){

1490

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

}

1491

1540

struct dirent *direntry;

1492

1541

int ret;

1493

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

1494

alphasort);

1495

if(numhooks == -1){

1496

if(errno == ENOENT){

1497

if(debug){

1498

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

1499

" found\n", hookdir);

1500

}

1501

} else {

1502

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);

1503

1548

}

1504

} else {

1505

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

1506

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

1507

direntry = direntries[i];

1508

char *fullname = NULL;

1509

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

1510

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){

1511

1610

perror_plus("asprintf");

1512

continue;

1513

}

1514

if(debug){

1515

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

1516

direntry->d_name);

1517

}

1518

pid_t hook_pid = fork();

1519

if(hook_pid == 0){

1520

/* Child */

1521

/* Raise privileges */

1522

raise_privileges_permanently();

1523

/* Set group */

1524

errno = 0;

1525

ret = setgid(0);

1526

if(ret == -1){

1527

perror_plus("setgid");

1528

}

1529

/* Reset supplementary groups */

1530

errno = 0;

1531

ret = setgroups(0, NULL);

1532

if(ret == -1){

1533

perror_plus("setgroups");

1534

}

1535

dup2(devnull, STDIN_FILENO);

1536

close(devnull);

1537

dup2(STDERR_FILENO, STDOUT_FILENO);

1538

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

1539

if(ret == -1){

1540

perror_plus("setenv");

1541

_exit(EX_OSERR);

1542

}

1543

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

1544

if(ret == -1){

1545

perror_plus("setenv");

1546

_exit(EX_OSERR);

1547

}

1548

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

1549

if(ret == -1){

1550

perror_plus("setenv");

1551

_exit(EX_OSERR);

1552

}

1553

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

1554

if(ret == -1){

1555

perror_plus("setenv");

1556

_exit(EX_OSERR);

1557

}

1558

char *delaystring;

1559

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

1560

if(ret == -1){

1561

perror_plus("asprintf");

1562

_exit(EX_OSERR);

1563

}

1564

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

1565

if(ret == -1){

1566

free(delaystring);

1567

perror_plus("setenv");

1568

_exit(EX_OSERR);

1569

}

1611

_exit(EX_OSERR);

1612

}

1613

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

1614

if(ret == -1){

1570

1615

free(delaystring);

1571

if(connect_to != NULL){

1572

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

1573

if(ret == -1){

1574

perror_plus("setenv");

1575

_exit(EX_OSERR);

1576

}

1577

}

1578

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

1579

perror_plus("execl");

1580

_exit(EXIT_FAILURE);

1581

}

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;

1582

1659

} else {

1583

int status;

1584

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

1585

perror_plus("waitpid");

1586

free(fullname);

1587

continue;

1588

}

1589

if(WIFEXITED(status)){

1590

if(WEXITSTATUS(status) != 0){

1591

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

1592

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

1593

WEXITSTATUS(status));

1594

free(fullname);

1595

continue;

1596

}

1597

} else if(WIFSIGNALED(status)){

1598

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

1599

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

1600

WTERMSIG(status));

1601

free(fullname);

1602

continue;

1603

} else {

1604

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

1605

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

1606

free(fullname);

1607

continue;

1608

}

1609

}

1610

free(fullname);

1611

if(debug){

1612

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

1613

direntry->d_name);

1614

}

1615

}

1616

close(devnull);

1617

}

1618

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);

1619

1677

}

1620

1678

1679

__attribute__((nonnull, warn_unused_result))

1621

1680

error_t bring_up_interface(const char *const interface,

1622

1681

const float delay){

1623

int sd = -1;

1624

1682

error_t old_errno = errno;

1625

error_t ret_errno = 0;

1626

int ret, ret_setflags;

1683

int ret;

1627

1684

struct ifreq network;

1628

1685

unsigned int if_index = if_nametoindex(interface);

1629

1686

if(if_index == 0){

1638

1695

}

1639

1696

1640

1697

if(not interface_is_up(interface)){

1641

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

1698

error_t ret_errno = 0, ioctl_errno = 0;

1699

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

1642

1700

ret_errno = errno;

1643

1701

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

1644

1702

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

1703

errno = old_errno;

1645

1704

return ret_errno;

1646

1705

}

1647

network.ifr_flags |= IFF_UP;

1706

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

1648

1707

1649

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1650

if(sd < 0){

1708

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

1709

if(sd == -1){

1651

1710

ret_errno = errno;

1652

1711

perror_plus("socket");

1653

1712

errno = old_errno;

1654

1713

return ret_errno;

1655

1714

}

1656

1715

1657

1716

if(quit_now){

1658

close(sd);

1717

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

1718

if(ret == -1){

1719

perror_plus("close");

1720

}

1659

1721

errno = old_errno;

1660

1722

return EINTR;

1661

1723

}

1665

1727

interface);

1666

1728

}

1667

1729

1668

/* Raise priviliges */

1669

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

}

1670

1736

1671

1737

#ifdef __linux__

1672

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1673

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

1674

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

1675

bool restore_loglevel = true;

1676

if(ret_linux == -1){

1677

restore_loglevel = false;

1678

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

}

1679

1749

}

1680

1750

#endif /* __linux__ */

1681

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

1682

ret_errno = errno;

1751

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

1752

ioctl_errno = errno;

1683

1753

#ifdef __linux__

1684

1754

if(restore_loglevel){

1685

1755

ret_linux = klogctl(7, NULL, 0);

1689

1759

}

1690

1760

#endif /* __linux__ */

1691

1761

1692

/* Lower privileges */

1693

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

}

1694

1771

1695

1772

/* Close the socket */

1696

1773

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

1699

1776

}

1700

1777

1701

1778

if(ret_setflags == -1){

1702

errno = ret_errno;

1779

errno = ioctl_errno;

1703

1780

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1704

1781

errno = old_errno;

1705

return ret_errno;

1782

return ioctl_errno;

1706

1783

}

1707

1784

} else if(debug){

1708

1785

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

1726

1803

return 0;

1727

1804

}

1728

1805

1806

__attribute__((nonnull, warn_unused_result))

1729

1807

error_t take_down_interface(const char *const interface){

1730

int sd = -1;

1731

1808

error_t old_errno = errno;

1732

error_t ret_errno = 0;

1733

int ret, ret_setflags;

1734

1809

struct ifreq network;

1735

1810

unsigned int if_index = if_nametoindex(interface);

1736

1811

if(if_index == 0){

1739

1814

return ENXIO;

1740

1815

}

1741

1816

if(interface_is_up(interface)){

1817

error_t ret_errno = 0, ioctl_errno = 0;

1742

1818

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

1743

1819

ret_errno = errno;

1744

1820

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

1745

1821

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

1822

errno = old_errno;

1746

1823

return ret_errno;

1747

1824

}

1748

1825

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

1749

1826

1750

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1751

if(sd < 0){

1827

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

1828

if(sd == -1){

1752

1829

ret_errno = errno;

1753

1830

perror_plus("socket");

1754

1831

errno = old_errno;

1760

1837

interface);

1761

1838

}

1762

1839

1763

/* Raise priviliges */

1764

raise_privileges();

1765

1766

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

1767

ret_errno = errno;

1768

1769

/* Lower privileges */

1770

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

}

1771

1859

1772

1860

/* Close the socket */

1773

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

1861

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

1774

1862

if(ret == -1){

1775

1863

perror_plus("close");

1776

1864

}

1777

1865

1778

1866

if(ret_setflags == -1){

1779

errno = ret_errno;

1867

errno = ioctl_errno;

1780

1868

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1781

1869

errno = old_errno;

1782

return ret_errno;

1870

return ioctl_errno;

1783

1871

}

1784

1872

} else if(debug){

1785

1873

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

1793

1881

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

1794

1882

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

1795

1883

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

1796

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

1884

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

1797

1885

.interfaces = NULL, .interfaces_size = 0 };

1798

1886

AvahiSServiceBrowser *sb = NULL;

1799

1887

error_t ret_errno;

1803

1891

int exitcode = EXIT_SUCCESS;

1804

1892

char *interfaces_to_take_down = NULL;

1805

1893

size_t interfaces_to_take_down_size = 0;

1806

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

1807

bool tempdir_created = false;

1894

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

1895

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

1896

char *tempdir = NULL;

1808

1897

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1809

1898

const char *seckey = PATHDIR "/" SECKEY;

1810

1899

const char *pubkey = PATHDIR "/" PUBKEY;

1811

1900

char *interfaces_hooks = NULL;

1812

size_t interfaces_hooks_size = 0;

1813

1901

1814

1902

bool gnutls_initialized = false;

1815

1903

bool gpgme_initialized = false;

1993

2081

/* Work around Debian bug #633582:

1994

2082

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

1995

2083

1996

/* Re-raise priviliges */

1997

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 {

1998

2090

struct stat st;

1999

2091

2000

2092

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

2040

2132

}

2041

2133

2042

2134

/* Lower privileges */

2043

lower_privileges();

2135

ret_errno = lower_privileges();

2136

if(ret_errno != 0){

2137

errno = ret_errno;

2138

perror_plus("Failed to lower privileges");

2139

}

2044

2140

}

2045

2141

}

2046

2142

2070

2166

goto end;

2071

2167

}

2072

2168

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

2073

interfaces_hooks_size = mc.interfaces_size;

2074

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2075

(int)',');

2076

}

2077

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

2078

interfaces_hooks : "", delay)){

2079

goto end;

2080

}

2169

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

2170

}

2171

run_network_hooks("start", interfaces_hooks != NULL ?

2172

interfaces_hooks : "", delay);

2081

2173

}

2082

2174

2083

2175

if(not debug){

2161

2253

2162

2254

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

2163

2255

if(mc.interfaces == NULL){

2164

struct dirent **direntries;

2256

struct dirent **direntries = NULL;

2165

2257

/* Look for any good interfaces */

2166

2258

ret = scandir(sys_class_net, &direntries, good_interface,

2167

2259

alphasort);

2171

2263

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

2172

2264

direntries[i]->d_name);

2173

2265

if(ret_errno != 0){

2266

errno = ret_errno;

2174

2267

perror_plus("argz_add");

2175

2268

continue;

2176

2269

}

2181

2274

}

2182

2275

free(direntries);

2183

2276

} else {

2184

free(direntries);

2277

if(ret == 0){

2278

free(direntries);

2279

}

2185

2280

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

2186

2281

exitcode = EXIT_FAILURE;

2187

2282

goto end;

2210

2305

break;

2211

2306

}

2212

2307

bool interface_was_up = interface_is_up(interface);

2213

ret = bring_up_interface(interface, delay);

2308

errno = bring_up_interface(interface, delay);

2214

2309

if(not interface_was_up){

2215

if(ret != 0){

2216

errno = ret;

2310

if(errno != 0){

2217

2311

perror_plus("Failed to bring up interface");

2218

2312

} else {

2219

ret_errno = argz_add(&interfaces_to_take_down,

2220

&interfaces_to_take_down_size,

2221

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

}

2222

2319

}

2223

2320

}

2224

2321

}

2253

2350

goto end;

2254

2351

}

2255

2352

2256

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){

2257

2363

perror_plus("mkdtemp");

2258

2364

goto end;

2259

2365

}

2260

tempdir_created = true;

2261

2366

2262

2367

if(quit_now){

2263

2368

goto end;

2338

2443

sleep((unsigned int)retry_interval);

2339

2444

}

2340

2445

2341

if (not quit_now){

2446

if(not quit_now){

2342

2447

exitcode = EXIT_SUCCESS;

2343

2448

}

2344

2449

2399

2504

if(debug){

2400

2505

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

2401

2506

}

2402

2507

2403

2508

ret = avahi_loop_with_timeout(simple_poll,

2404

2509

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

2405

2510

if(debug){

2446

2551

}

2447

2552

}

2448

2553

2449

/* Re-raise priviliges */

2554

/* Re-raise privileges */

2450

2555

{

2451

raise_privileges();

2452

2453

/* Run network hooks */

2454

run_network_hooks("stop", interfaces_hooks != NULL ?

2455

interfaces_hooks : "", delay);

2456

2457

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

2458

{

2459

char *interface = NULL;

2460

while((interface=argz_next(interfaces_to_take_down,

2461

interfaces_to_take_down_size,

2462

interface))){

2463

ret_errno = take_down_interface(interface);

2464

if(ret_errno != 0){

2465

errno = ret_errno;

2466

perror_plus("Failed to take down interface");

2467

}

2468

}

2469

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

2470

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

2471

" down\n");

2472

}

2473

}

2474

2475

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

}

2476

2590

}

2477

2591

2478

2592

free(interfaces_to_take_down);

2479

2593

free(interfaces_hooks);

2480

2594

2481

2595

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

2482

if(tempdir_created){

2596

if(tempdir != NULL){

2483

2597

struct dirent **direntries = NULL;

2484

struct dirent *direntry = NULL;

2485

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

2486

alphasort);

2487

if (numentries > 0){

2488

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

2489

direntry = direntries[i];

2490

char *fullname = NULL;

2491

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

2492

direntry->d_name);

2493

if(ret < 0){

2494

perror_plus("asprintf");

2495

continue;

2496

}

2497

ret = remove(fullname);

2498

if(ret == -1){

2499

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

2500

strerror(errno));

2501

}

2502

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

}

2503

2634

}

2504

}

2505

2506

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

2507

free(direntries);

2508

if (numentries == -1){

2509

perror_plus("scandir");

2510

}

2511

ret = rmdir(tempdir);

2512

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

2513

perror_plus("rmdir");

2635

TEMP_FAILURE_RETRY(close(tempdir_fd));

2514

2636

}

2515

2637

}

2516

2638