/mandos/release : revision 237.7.132

41

42

#include <stdio.h> /* fprintf(), stderr, fwrite(),

43

stdout, ferror(), remove() */

44

#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

44

#include <stdint.h> /* uint16_t, uint32_t */

45

#include <stddef.h> /* NULL, size_t, ssize_t */

46

#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

47

strtof(), abort() */

61

*/

62

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

63

strtoimax() */

64

#include <assert.h> /* assert() */

64

65

#include <errno.h> /* perror(), errno,

65

66

program_invocation_short_name */

66

67

#include <time.h> /* nanosleep(), time(), sleep() */

87

88

#include <sys/wait.h> /* waitpid(), WIFEXITED(),

88

89

WEXITSTATUS(), WTERMSIG() */

89

90

#include <grp.h> /* setgroups() */

90

#include <argz.h> /* argz_add_sep(), argz_next(),

91

argz_delete(), argz_append(),

92

argz_stringify(), argz_add(),

93

argz_count() */

94

91

95

92

#ifdef __linux__

96

93

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

138

135

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

139

136

char *connect_to = NULL;

140

137

const char *hookdir = HOOKDIR;

141

uid_t uid = 65534;

142

gid_t gid = 65534;

143

138

144

139

/* Doubly linked list that need to be circularly linked when used */

145

140

typedef struct server{

146

141

const char *ip;

147

in_port_t port;

142

uint16_t port;

148

143

AvahiIfIndex if_index;

149

144

int af;

150

145

struct timespec last_seen;

154

149

155

150

/* Used for passing in values through the Avahi callback functions */

156

151

typedef struct {

152

AvahiSimplePoll *simple_poll;

157

153

AvahiServer *server;

158

154

gnutls_certificate_credentials_t cred;

159

155

unsigned int dh_bits;

163

159

server *current_server;

164

160

} mandos_context;

165

161

166

/* global so signal handler can reach it*/

167

AvahiSimplePoll *simple_poll;

168

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

169

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

170

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

162

/* global context so signal handler can reach it*/

163

mandos_context mc = { .simple_poll = NULL, .server = NULL,

164

.dh_bits = 1024, .priority = "SECURE256"

165

":!CTYPE-X.509:+CTYPE-OPENPGP",

166

.current_server = NULL };

171

167

172

168

sig_atomic_t quit_now = 0;

173

169

int signal_received = 0;

209

205

}

210

206

211

207

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

212

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

208

bool add_server(const char *ip, uint16_t port, AvahiIfIndex if_index,

213

209

int af){

214

210

int ret;

215

211

server *new_server = malloc(sizeof(server));

253

249

gpgme_error_t rc;

254

250

gpgme_engine_info_t engine_info;

255

251

252

256

253

/*

257

254

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

258

255

*/

468

465

}

469

466

470

467

static const char * safer_gnutls_strerror(int value){

471

const char *ret = gnutls_strerror(value);

468

const char *ret = gnutls_strerror(value); /* Spurious warning from

469

-Wunreachable-code */

472

470

if(ret == NULL)

473

471

ret = "(unknown)";

474

472

return ret;

619

617

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

620

618

621

619

/* Called when a Mandos server is found */

622

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

620

static int start_mandos_communication(const char *ip, uint16_t port,

623

621

AvahiIfIndex if_index,

624

622

int af){

625

623

int ret, tcp_sd = -1;

664

662

665

663

if(debug){

666

664

fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"

667

PRIuMAX "\n", ip, (uintmax_t)port);

665

PRIu16 "\n", ip, port);

668

666

}

669

667

670

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

701

699

goto mandos_end;

702

700

}

703

701

if(af == AF_INET6){

704

to.in6.sin6_port = htons(port);

702

to.in6.sin6_port = htons(port); /* Spurious warnings from

703

-Wconversion and

704

-Wunreachable-code */

705

706

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

706

707

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

707

708

-Wunreachable-code*/

731

732

if(if_indextoname((unsigned int)if_index, interface) == NULL){

732

733

perror_plus("if_indextoname");

733

734

} else {

734

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX

735

"\n", ip, interface, (uintmax_t)port);

735

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16

736

"\n", ip, interface, port);

736

737

}

737

738

} else {

738

fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",

739

ip, (uintmax_t)port);

739

fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",

740

ip, port);

740

741

}

741

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

742

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

820

821

goto mandos_end;

821

822

}

822

823

/* This casting via intptr_t is to eliminate warning about casting

824

an int to a pointer type. This is exactly how the GnuTLS Guile

825

function "set-session-transport-fd!" does it. */

826

gnutls_transport_set_ptr(session,

827

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

824

/* Spurious warning from -Wint-to-pointer-cast */

825

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

828

826

829

827

if(quit_now){

830

828

errno = EINTR;

1003

1001

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1004

1002

flags,

1005

1003

AVAHI_GCC_UNUSED void* userdata){

1006

if(r == NULL){

1007

return;

1008

}

1004

assert(r);

1009

1005

1010

1006

/* Called whenever a service has been resolved successfully or

1011

1007

timed out */

1032

1028

PRIdMAX ") on port %" PRIu16 "\n", name,

1033

1029

host_name, ip, (intmax_t)interface, port);

1034

1030

}

1035

int ret = start_mandos_communication(ip, (in_port_t)port,

1036

interface,

1031

int ret = start_mandos_communication(ip, port, interface,

1037

1032

avahi_proto_to_af(proto));

1038

1033

if(ret == 0){

1039

avahi_simple_poll_quit(simple_poll);

1034

avahi_simple_poll_quit(mc.simple_poll);

1040

1035

} else {

1041

if(not add_server(ip, (in_port_t)port, interface,

1036

if(not add_server(ip, port, interface,

1042

1037

avahi_proto_to_af(proto))){

1043

1038

fprintf_plus(stderr, "Failed to add server \"%s\" to server"

1044

1039

" list\n", name);

1059

1054

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1060

1055

flags,

1061

1056

AVAHI_GCC_UNUSED void* userdata){

1062

if(b == NULL){

1063

return;

1064

}

1057

assert(b);

1065

1058

1066

1059

/* Called whenever a new services becomes available on the LAN or

1067

1060

is removed from the LAN */

1076

1069

1077

1070

fprintf_plus(stderr, "(Avahi browser) %s\n",

1078

1071

avahi_strerror(avahi_server_errno(mc.server)));

1079

avahi_simple_poll_quit(simple_poll);

1072

avahi_simple_poll_quit(mc.simple_poll);

1080

1073

return;

1081

1074

1082

1075

case AVAHI_BROWSER_NEW:

1115

1108

signal_received = sig;

1116

1109

int old_errno = errno;

1117

1110

/* set main loop to exit */

1118

if(simple_poll != NULL){

1119

avahi_simple_poll_quit(simple_poll);

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1120

1113

}

1121

1114

errno = old_errno;

1122

1115

}

1123

1116

1124

1117

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

1125

1118

int ret;

1126

error_t ret_errno;

1127

1119

1128

1120

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

1129

1121

if(s < 0){

1130

ret_errno = errno;

1131

1122

perror_plus("socket");

1132

errno = ret_errno;

1133

1123

return false;

1134

1124

}

1135

1125

strcpy(ifr->ifr_name, ifname);

1136

1126

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1137

1127

if(ret == -1){

1138

1128

if(debug){

1139

ret_errno = errno;

1140

1129

perror_plus("ioctl SIOCGIFFLAGS");

1141

errno = ret_errno;

1142

1130

}

1143

1131

return false;

1144

1132

}

1213

1201

}

1214

1202

1215

1203

/*

1216

* This function determines if a network interface is up.

1217

*/

1218

bool interface_is_up(const char *interface){

1219

struct ifreq ifr;

1220

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

1221

if(debug){

1222

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

1223

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

1224

}

1225

return false;

1226

}

1227

1228

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

1229

}

1230

1231

/*

1232

* This function determines if a network interface is running

1233

*/

1234

bool interface_is_running(const char *interface){

1235

struct ifreq ifr;

1236

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

1237

if(debug){

1238

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

1239

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

1240

}

1241

return false;

1242

}

1243

1244

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

1204

* This function determines if a directory entry in /sys/class/net

1205

* corresponds to an acceptable network device which is up.

1206

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

1207

*/

1208

int up_interface(const struct dirent *if_entry){

1209

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

1210

return 0;

1211

}

1212

1213

struct ifreq ifr;

1214

if(not get_flags(if_entry->d_name, &ifr)){

1215

if(debug){

1216

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

1217

"\"%s\"\n", if_entry->d_name);

1218

}

1219

return 0;

1220

}

1221

1222

/* Reject down interfaces */

1223

if(not (ifr.ifr_flags & IFF_UP)){

1224

if(debug){

1225

fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",

1226

if_entry->d_name);

1227

}

1228

return 0;

1229

}

1230

1231

/* Reject non-running interfaces */

1232

if(not (ifr.ifr_flags & IFF_RUNNING)){

1233

if(debug){

1234

fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",

1235

if_entry->d_name);

1236

}

1237

return 0;

1238

}

1239

1240

if(not good_flags(if_entry->d_name, &ifr)){

1241

return 0;

1242

}

1243

return 1;

1245

1244

}

1246

1245

1247

1246

int notdotentries(const struct dirent *direntry){

1364

1363

mc.current_server->if_index,

1365

1364

mc.current_server->af);

1366

1365

if(ret == 0){

1367

avahi_simple_poll_quit(simple_poll);

1366

avahi_simple_poll_quit(mc.simple_poll);

1368

1367

return 0;

1369

1368

}

1370

1369

ret = clock_gettime(CLOCK_MONOTONIC,

1388

1387

}

1389

1388

}

1390

1389

1391

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

1392

error_t raise_privileges(void){

1393

error_t old_errno = errno;

1394

error_t ret_errno = 0;

1395

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

1396

ret_errno = errno;

1397

perror_plus("seteuid");

1398

}

1399

errno = old_errno;

1400

return ret_errno;

1401

}

1402

1403

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

1404

error_t raise_privileges_permanently(void){

1405

error_t old_errno = errno;

1406

error_t ret_errno = raise_privileges();

1407

if(ret_errno != 0){

1408

errno = old_errno;

1409

return ret_errno;

1410

}

1411

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

1412

ret_errno = errno;

1413

perror_plus("seteuid");

1414

}

1415

errno = old_errno;

1416

return ret_errno;

1417

}

1418

1419

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

1420

error_t lower_privileges(void){

1421

error_t old_errno = errno;

1422

error_t ret_errno = 0;

1423

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

1424

ret_errno = errno;

1425

perror_plus("seteuid");

1426

}

1427

errno = old_errno;

1428

return ret_errno;

1429

}

1430

1431

/* Lower privileges permanently */

1432

error_t lower_privileges_permanently(void){

1433

error_t old_errno = errno;

1434

error_t ret_errno = 0;

1435

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

1436

ret_errno = errno;

1437

perror_plus("setuid");

1438

}

1439

errno = old_errno;

1440

return ret_errno;

1441

}

1442

1443

1390

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

1444

1391

const float delay){

1445

1392

struct dirent **direntries;

1448

1395

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

1449

1396

alphasort);

1450

1397

if(numhooks == -1){

1451

if(errno == ENOENT){

1452

if(debug){

1453

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

1454

" found\n", hookdir);

1455

}

1456

} else {

1457

perror_plus("scandir");

1458

}

1398

perror_plus("scandir");

1459

1399

} else {

1460

1400

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

1461

1401

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

1474

1414

if(hook_pid == 0){

1475

1415

/* Child */

1476

1416

/* Raise privileges */

1477

raise_privileges_permanently();

1417

errno = 0;

1418

ret = seteuid(0);

1419

if(ret == -1){

1420

perror_plus("seteuid");

1421

}

1422

/* Raise privileges even more */

1423

errno = 0;

1424

ret = setuid(0);

1425

if(ret == -1){

1426

perror_plus("setuid");

1427

}

1478

1428

/* Set group */

1479

1429

errno = 0;

1480

1430

ret = setgid(0);

1573

1523

return true;

1574

1524

}

1575

1525

1576

error_t bring_up_interface(const char *const interface,

1577

const float delay){

1578

int sd = -1;

1579

error_t old_errno = errno;

1580

error_t ret_errno = 0;

1581

int ret, ret_setflags;

1582

struct ifreq network;

1583

unsigned int if_index = if_nametoindex(interface);

1584

if(if_index == 0){

1585

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1586

errno = old_errno;

1587

return ENXIO;

1588

}

1589

1590

if(quit_now){

1591

errno = old_errno;

1592

return EINTR;

1593

}

1594

1595

if(not interface_is_up(interface)){

1596

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

1597

ret_errno = errno;

1598

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

1599

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

1600

return ret_errno;

1601

}

1602

network.ifr_flags |= IFF_UP;

1603

1604

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1605

if(sd < 0){

1606

ret_errno = errno;

1607

perror_plus("socket");

1608

errno = old_errno;

1609

return ret_errno;

1610

}

1611

1612

if(quit_now){

1613

close(sd);

1614

errno = old_errno;

1615

return EINTR;

1616

}

1617

1618

if(debug){

1619

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

1620

interface);

1621

}

1622

1623

/* Raise priviliges */

1624

raise_privileges();

1625

1626

#ifdef __linux__

1627

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1628

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

1629

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

1630

bool restore_loglevel = true;

1631

if(ret_linux == -1){

1632

restore_loglevel = false;

1633

perror_plus("klogctl");

1634

}

1635

#endif /* __linux__ */

1636

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

1637

ret_errno = errno;

1638

#ifdef __linux__

1639

if(restore_loglevel){

1640

ret_linux = klogctl(7, NULL, 0);

1641

if(ret_linux == -1){

1642

perror_plus("klogctl");

1643

}

1644

}

1645

#endif /* __linux__ */

1646

1647

/* Lower privileges */

1648

lower_privileges();

1649

1650

/* Close the socket */

1651

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

1652

if(ret == -1){

1653

perror_plus("close");

1654

}

1655

1656

if(ret_setflags == -1){

1657

errno = ret_errno;

1658

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1659

errno = old_errno;

1660

return ret_errno;

1661

}

1662

} else if(debug){

1663

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

1664

interface);

1665

}

1666

1667

/* Sleep checking until interface is running.

1668

Check every 0.25s, up to total time of delay */

1669

for(int i=0; i < delay * 4; i++){

1670

if(interface_is_running(interface)){

1671

break;

1672

}

1673

struct timespec sleeptime = { .tv_nsec = 250000000 };

1674

ret = nanosleep(&sleeptime, NULL);

1675

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

1676

perror_plus("nanosleep");

1677

}

1678

}

1679

1680

errno = old_errno;

1681

return 0;

1682

}

1683

1684

error_t take_down_interface(const char *const interface){

1685

int sd = -1;

1686

error_t old_errno = errno;

1687

error_t ret_errno = 0;

1688

int ret, ret_setflags;

1689

struct ifreq network;

1690

unsigned int if_index = if_nametoindex(interface);

1691

if(if_index == 0){

1692

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1693

errno = old_errno;

1694

return ENXIO;

1695

}

1696

if(interface_is_up(interface)){

1697

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

1698

ret_errno = errno;

1699

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

1700

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

1701

return ret_errno;

1702

}

1703

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

1704

1705

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1706

if(sd < 0){

1707

ret_errno = errno;

1708

perror_plus("socket");

1709

errno = old_errno;

1710

return ret_errno;

1711

}

1712

1713

if(debug){

1714

fprintf_plus(stderr, "Taking down interface \"%s\"\n",

1715

interface);

1716

}

1717

1718

/* Raise priviliges */

1719

raise_privileges();

1720

1721

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

1722

ret_errno = errno;

1723

1724

/* Lower privileges */

1725

lower_privileges();

1726

1727

/* Close the socket */

1728

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

1729

if(ret == -1){

1730

perror_plus("close");

1731

}

1732

1733

if(ret_setflags == -1){

1734

errno = ret_errno;

1735

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1736

errno = old_errno;

1737

return ret_errno;

1738

}

1739

} else if(debug){

1740

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

1741

interface);

1742

}

1743

1744

errno = old_errno;

1745

return 0;

1746

}

1747

1748

1526

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

1749

1527

AvahiSServiceBrowser *sb = NULL;

1750

error_t ret_errno;

1528

int error;

1751

1529

int ret;

1752

1530

intmax_t tmpmax;

1753

1531

char *tmp;

1754

1532

int exitcode = EXIT_SUCCESS;

1755

char *interfaces = NULL;

1756

size_t interfaces_size = 0;

1757

char *interfaces_to_take_down = NULL;

1758

size_t interfaces_to_take_down_size = 0;

1533

const char *interface = "";

1534

struct ifreq network;

1535

int sd = -1;

1536

bool take_down_interface = false;

1537

uid_t uid;

1538

gid_t gid;

1759

1539

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

1760

1540

bool tempdir_created = false;

1761

1541

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1762

1542

const char *seckey = PATHDIR "/" SECKEY;

1763

1543

const char *pubkey = PATHDIR "/" PUBKEY;

1764

char *interfaces_hooks = NULL;

1765

size_t interfaces_hooks_size = 0;

1766

1544

1767

1545

bool gnutls_initialized = false;

1768

1546

bool gpgme_initialized = false;

1859

1637

connect_to = arg;

1860

1638

break;

1861

1639

case 'i': /* --interface */

1862

ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,

1863

(int)',');

1864

if(ret_errno != 0){

1865

argp_error(state, "%s", strerror(ret_errno));

1866

}

1640

interface = arg;

1867

1641

break;

1868

1642

case 's': /* --seckey */

1869

1643

seckey = arg;

1947

1721

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

1948

1722

1949

1723

/* Re-raise priviliges */

1950

if(raise_privileges() == 0){

1724

errno = 0;

1725

ret = seteuid(0);

1726

if(ret == -1){

1727

perror_plus("seteuid");

1728

} else {

1951

1729

struct stat st;

1952

1730

1953

1731

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

2001

1779

}

2002

1780

}

2003

1781

2004

/* Remove empty interface names */

2005

{

2006

char *interface = NULL;

2007

while((interface = argz_next(interfaces, interfaces_size,

2008

interface))){

2009

if(if_nametoindex(interface) == 0){

2010

if(interface[0] != '\0' and strcmp(interface, "none") != 0){

2011

fprintf_plus(stderr, "Not using nonexisting interface"

2012

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

2013

}

2014

argz_delete(&interfaces, &interfaces_size, interface);

2015

interface = NULL;

2016

}

2017

}

2018

}

2019

2020

1782

/* Run network hooks */

2021

{

2022

2023

if(interfaces != NULL){

2024

interfaces_hooks = malloc(interfaces_size);

2025

if(interfaces_hooks == NULL){

2026

perror_plus("malloc");

2027

goto end;

2028

}

2029

memcpy(interfaces_hooks, interfaces, interfaces_size);

2030

interfaces_hooks_size = interfaces_size;

2031

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2032

(int)',');

2033

}

2034

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

2035

interfaces_hooks : "", delay)){

2036

goto end;

2037

}

1783

if(not run_network_hooks("start", interface, delay)){

1784

goto end;

2038

1785

}

2039

1786

2040

1787

if(not debug){

2041

1788

avahi_set_log_function(empty_log);

2042

1789

}

2043

1790

1791

if(interface[0] == '\0'){

1792

struct dirent **direntries;

1793

/* First look for interfaces that are up */

1794

ret = scandir(sys_class_net, &direntries, up_interface,

1795

alphasort);

1796

if(ret == 0){

1797

/* No up interfaces, look for any good interfaces */

1798

free(direntries);

1799

ret = scandir(sys_class_net, &direntries, good_interface,

1800

alphasort);

1801

}

1802

if(ret >= 1){

1803

/* Pick the first interface returned */

1804

interface = strdup(direntries[0]->d_name);

1805

if(debug){

1806

fprintf_plus(stderr, "Using interface \"%s\"\n", interface);

1807

}

1808

if(interface == NULL){

1809

perror_plus("malloc");

1810

free(direntries);

1811

exitcode = EXIT_FAILURE;

1812

goto end;

1813

}

1814

free(direntries);

1815

} else {

1816

free(direntries);

1817

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

1818

exitcode = EXIT_FAILURE;

1819

goto end;

1820

}

1821

}

1822

2044

1823

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

2045

1824

from the signal handler */

2046

1825

/* Initialize the pseudo-RNG for Avahi */

2047

1826

srand((unsigned int) time(NULL));

2048

simple_poll = avahi_simple_poll_new();

2049

if(simple_poll == NULL){

1827

mc.simple_poll = avahi_simple_poll_new();

1828

if(mc.simple_poll == NULL){

2050

1829

fprintf_plus(stderr,

2051

1830

"Avahi: Failed to create simple poll object.\n");

2052

1831

exitcode = EX_UNAVAILABLE;

2116

1895

}

2117

1896

}

2118

1897

2119

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

2120

if(interfaces == NULL){

2121

struct dirent **direntries;

2122

/* Look for any good interfaces */

2123

ret = scandir(sys_class_net, &direntries, good_interface,

2124

alphasort);

2125

if(ret >= 1){

2126

/* Add all found interfaces to interfaces list */

2127

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

2128

ret_errno = argz_add(&interfaces, &interfaces_size,

2129

direntries[i]->d_name);

2130

if(ret_errno != 0){

2131

perror_plus("argz_add");

2132

continue;

2133

}

2134

if(debug){

2135

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

2136

direntries[i]->d_name);

2137

}

2138

}

2139

free(direntries);

2140

} else {

2141

free(direntries);

2142

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

2143

exitcode = EXIT_FAILURE;

2144

goto end;

2145

}

2146

}

2147

2148

/* If we only got one interface, explicitly use only that one */

2149

if(argz_count(interfaces, interfaces_size) == 1){

2150

if(debug){

2151

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2152

interfaces);

2153

}

2154

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2155

}

2156

2157

/* Bring up interfaces which are down */

2158

if(not (argz_count(interfaces, interfaces_size) == 1

2159

and strcmp(interfaces, "none") == 0)){

2160

char *interface = NULL;

2161

while((interface = argz_next(interfaces, interfaces_size,

2162

interface))){

2163

bool interface_was_up = interface_is_up(interface);

2164

ret = bring_up_interface(interface, delay);

2165

if(not interface_was_up){

2166

if(ret != 0){

2167

errno = ret;

2168

perror_plus("Failed to bring up interface");

2169

} else {

2170

ret_errno = argz_add(&interfaces_to_take_down,

2171

&interfaces_to_take_down_size,

2172

interface);

2173

}

2174

}

2175

}

2176

free(interfaces);

2177

interfaces = NULL;

2178

interfaces_size = 0;

2179

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

2180

fprintf_plus(stderr, "No interfaces were brought up\n");

1898

/* If the interface is down, bring it up */

1899

if(strcmp(interface, "none") != 0){

1900

if_index = (AvahiIfIndex) if_nametoindex(interface);

1901

if(if_index == 0){

1902

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1903

exitcode = EX_UNAVAILABLE;

1904

goto end;

1905

}

1906

1907

if(quit_now){

1908

goto end;

1909

}

1910

1911

/* Re-raise priviliges */

1912

errno = 0;

1913

ret = seteuid(0);

1914

if(ret == -1){

1915

perror_plus("seteuid");

1916

}

1917

1918

#ifdef __linux__

1919

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1920

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

1921

ret = klogctl(8, NULL, 5);

1922

bool restore_loglevel = true;

1923

if(ret == -1){

1924

restore_loglevel = false;

1925

perror_plus("klogctl");

1926

}

1927

#endif /* __linux__ */

1928

1929

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1930

if(sd < 0){

1931

perror_plus("socket");

1932

exitcode = EX_OSERR;

1933

#ifdef __linux__

1934

if(restore_loglevel){

1935

ret = klogctl(7, NULL, 0);

1936

if(ret == -1){

1937

perror_plus("klogctl");

1938

}

1939

}

1940

#endif /* __linux__ */

1941

/* Lower privileges */

1942

errno = 0;

1943

ret = seteuid(uid);

1944

if(ret == -1){

1945

perror_plus("seteuid");

1946

}

1947

goto end;

1948

}

1949

strcpy(network.ifr_name, interface);

1950

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1951

if(ret == -1){

1952

perror_plus("ioctl SIOCGIFFLAGS");

1953

#ifdef __linux__

1954

if(restore_loglevel){

1955

ret = klogctl(7, NULL, 0);

1956

if(ret == -1){

1957

perror_plus("klogctl");

1958

}

1959

}

1960

#endif /* __linux__ */

1961

exitcode = EX_OSERR;

1962

/* Lower privileges */

1963

errno = 0;

1964

ret = seteuid(uid);

1965

if(ret == -1){

1966

perror_plus("seteuid");

1967

}

1968

goto end;

1969

}

1970

if((network.ifr_flags & IFF_UP) == 0){

1971

network.ifr_flags |= IFF_UP;

1972

take_down_interface = true;

1973

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

1974

if(ret == -1){

1975

take_down_interface = false;

1976

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1977

exitcode = EX_OSERR;

1978

#ifdef __linux__

1979

if(restore_loglevel){

1980

ret = klogctl(7, NULL, 0);

1981

if(ret == -1){

1982

perror_plus("klogctl");

1983

}

1984

}

1985

#endif /* __linux__ */

1986

/* Lower privileges */

1987

errno = 0;

1988

ret = seteuid(uid);

1989

if(ret == -1){

1990

perror_plus("seteuid");

1991

}

1992

goto end;

1993

}

1994

}

1995

/* Sleep checking until interface is running.

1996

Check every 0.25s, up to total time of delay */

1997

for(int i=0; i < delay * 4; i++){

1998

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1999

if(ret == -1){

2000

perror_plus("ioctl SIOCGIFFLAGS");

2001

} else if(network.ifr_flags & IFF_RUNNING){

2002

break;

2003

}

2004

struct timespec sleeptime = { .tv_nsec = 250000000 };

2005

ret = nanosleep(&sleeptime, NULL);

2006

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

2007

perror_plus("nanosleep");

2008

}

2009

}

2010

if(not take_down_interface){

2011

/* We won't need the socket anymore */

2012

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

2013

if(ret == -1){

2014

perror_plus("close");

2015

}

2016

}

2017

#ifdef __linux__

2018

if(restore_loglevel){

2019

/* Restores kernel loglevel to default */

2020

ret = klogctl(7, NULL, 0);

2021

if(ret == -1){

2022

perror_plus("klogctl");

2023

}

2024

}

2025

#endif /* __linux__ */

2026

/* Lower privileges */

2027

errno = 0;

2028

/* Lower privileges */

2029

ret = seteuid(uid);

2030

if(ret == -1){

2031

perror_plus("seteuid");

2181

2032

}

2182

2033

}

2183

2034

2224

2075

/* Connect directly, do not use Zeroconf */

2225

2076

/* (Mainly meant for debugging) */

2226

2077

char *address = strrchr(connect_to, ':');

2227

2228

2078

if(address == NULL){

2229

2079

fprintf_plus(stderr, "No colon in address\n");

2230

2080

exitcode = EX_USAGE;

2235

2085

goto end;

2236

2086

}

2237

2087

2238

in_port_t port;

2088

uint16_t port;

2239

2089

errno = 0;

2240

2090

tmpmax = strtoimax(address+1, &tmp, 10);

2241

2091

if(errno != 0 or tmp == address+1 or *tmp != '\0'

2242

or tmpmax != (in_port_t)tmpmax){

2092

or tmpmax != (uint16_t)tmpmax){

2243

2093

fprintf_plus(stderr, "Bad port number\n");

2244

2094

exitcode = EX_USAGE;

2245

2095

goto end;

2249

2099

goto end;

2250

2100

}

2251

2101

2252

port = (in_port_t)tmpmax;

2102

port = (uint16_t)tmpmax;

2253

2103

*address = '\0';

2254

2104

/* Colon in address indicates IPv6 */

2255

2105

int af;

2303

2153

config.publish_domain = 0;

2304

2154

2305

2155

/* Allocate a new server */

2306

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2307

&config, NULL, NULL, &ret_errno);

2156

mc.server = avahi_server_new(avahi_simple_poll_get

2157

(mc.simple_poll), &config, NULL,

2158

NULL, &error);

2308

2159

2309

2160

/* Free the Avahi configuration data */

2310

2161

avahi_server_config_free(&config);

2313

2164

/* Check if creating the Avahi server object succeeded */

2314

2165

if(mc.server == NULL){

2315

2166

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2316

avahi_strerror(ret_errno));

2167

avahi_strerror(error));

2317

2168

exitcode = EX_UNAVAILABLE;

2318

2169

goto end;

2319

2170

}

2343

2194

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

2344

2195

}

2345

2196

2346

ret = avahi_loop_with_timeout(simple_poll,

2197

ret = avahi_loop_with_timeout(mc.simple_poll,

2347

2198

(int)(retry_interval * 1000));

2348

2199

if(debug){

2349

2200

fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",

2363

2214

if(mc.server != NULL)

2364

2215

avahi_server_free(mc.server);

2365

2216

2366

if(simple_poll != NULL)

2367

avahi_simple_poll_free(simple_poll);

2217

if(mc.simple_poll != NULL)

2218

avahi_simple_poll_free(mc.simple_poll);

2368

2219

2369

2220

if(gnutls_initialized){

2370

2221

gnutls_certificate_free_credentials(mc.cred);

2387

2238

}

2388

2239

}

2389

2240

2241

/* Run network hooks */

2242

run_network_hooks("stop", interface, delay);

2243

2390

2244

/* Re-raise priviliges */

2391

2245

{

2392

raise_privileges();

2393

2394

/* Run network hooks */

2395

run_network_hooks("stop", interfaces_hooks != NULL ?

2396

interfaces_hooks : "", delay);

2397

2398

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

2399

{

2400

char *interface = NULL;

2401

while((interface=argz_next(interfaces_to_take_down,

2402

interfaces_to_take_down_size,

2403

interface))){

2404

ret_errno = take_down_interface(interface);

2405

if(ret_errno != 0){

2406

errno = ret_errno;

2407

perror_plus("Failed to take down interface");

2246

errno = 0;

2247

ret = seteuid(0);

2248

if(ret == -1){

2249

perror_plus("seteuid");

2250

}

2251

2252

/* Take down the network interface */

2253

if(take_down_interface and geteuid() == 0){

2254

ret = ioctl(sd, SIOCGIFFLAGS, &network);

2255

if(ret == -1){

2256

perror_plus("ioctl SIOCGIFFLAGS");

2257

} else if(network.ifr_flags & IFF_UP){

2258

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

2259

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

2260

if(ret == -1){

2261

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2408

2262

}

2409

2263

}

2410

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

2411

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

2412

" down\n");

2264

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

2265

if(ret == -1){

2266

perror_plus("close");

2413

2267

}

2414

2268

}

2415

2416

lower_privileges_permanently();

2417

}

2418

2419

free(interfaces_to_take_down);

2420

free(interfaces_hooks);

2269

}

2270

/* Lower privileges permanently */

2271

errno = 0;

2272

ret = setuid(uid);

2273

if(ret == -1){

2274

perror_plus("setuid");

2275

}

2421

2276

2422

2277

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

2423

2278

if(tempdir_created){