/mandos/trunk : revision 761

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(),

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

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

61

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

62

*/

63

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

73

*/

74

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

75

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

76

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

76

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

77

unlinkat() */

77

78

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

78

79

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

79

80

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

141

142

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

142

143

char *connect_to = NULL;

143

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

144

146

uid_t uid = 65534;

145

147

gid_t gid = 65534;

146

148

232

234

.af = af };

233

235

if(new_server->ip == NULL){

234

236

perror_plus("strdup");

237

free(new_server);

235

238

return false;

236

239

}

237

240

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

238

241

if(ret == -1){

239

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

free((char *)(new_server->ip));

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

240

252

return false;

241

253

}

242

254

/* Special case of first server */

258

270

* Initialize GPGME.

259

271

*/

260

272

__attribute__((nonnull, warn_unused_result))

261

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

262

const char *tempdir, mandos_context *mc){

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

263

277

gpgme_error_t rc;

264

278

gpgme_engine_info_t engine_info;

265

279

266

280

/*

267

281

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

268

282

*/

269

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

270

284

int ret;

271

285

int fd;

272

286

gpgme_data_t pgp_data;

479

493

return plaintext_length;

480

494

}

481

495

496

__attribute__((warn_unused_result, const))

497

static const char *safe_string(const char *str){

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

482

503

__attribute__((warn_unused_result))

483

504

static const char *safer_gnutls_strerror(int value){

484

505

const char *ret = gnutls_strerror(value);

485

if(ret == NULL)

486

ret = "(unknown)";

487

return ret;

506

return safe_string(ret);

488

507

}

489

508

490

509

/* GnuTLS log function callback */

499

518

const char *seckeyfilename,

500

519

mandos_context *mc){

501

520

int ret;

521

unsigned int uret;

502

522

503

523

if(debug){

504

524

fprintf_plus(stderr, "Initializing GnuTLS\n");

555

575

safer_gnutls_strerror(ret));

556

576

goto globalfail;

557

577

}

578

if(mc->dh_bits == 0){

579

/* Find out the optimal number of DH bits */

580

/* Try to read the private key file */

581

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

585

while(true){

586

buffer_capacity = incbuffer((char **)&buffer.data,

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

590

perror_plus("incbuffer");

591

free(buffer.data);

592

buffer.data = NULL;

593

break;

594

}

595

ssize_t bytes_read = read(secfile, buffer.data + buffer.size,

596

BUFFER_SIZE);

597

/* EOF */

598

if(bytes_read == 0){

599

break;

600

}

601

/* check bytes_read for failure */

602

if(bytes_read < 0){

603

perror_plus("read");

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

/* If successful, use buffer to parse private key */

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

" structure: %s", safer_gnutls_strerror(ret));

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

627

if(ret != GNUTLS_E_SUCCESS){

628

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

629

safer_gnutls_strerror(ret));

630

privkey = NULL;

631

}

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

/* Use private key to suggest an appropriate sec_param */

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

fprintf_plus(stderr, "This OpenPGP key implies using a"

640

" GnuTLS security parameter \"%s\".\n",

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

644

}

645

}

646

}

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

650

if(debug){

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

653

safe_string(gnutls_sec_param_get_name

654

(sec_param)));

655

}

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

663

" implies %u DH bits; using that.\n",

664

safe_string(gnutls_sec_param_get_name

665

(sec_param)),

666

mc->dh_bits);

667

}

668

} else {

669

fprintf_plus(stderr, "Failed to get implied number of DH"

670

" bits for security parameter \"%s\"): %s\n",

671

safe_string(gnutls_sec_param_get_name(sec_param)),

672

safer_gnutls_strerror(ret));

673

goto globalfail;

674

}

675

} else if(debug){

676

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

677

mc->dh_bits);

678

}

558

679

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

559

680

if(ret != GNUTLS_E_SUCCESS){

560

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

561

safer_gnutls_strerror(ret));

681

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u bits):"

682

" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));

562

683

goto globalfail;

563

684

}

564

685

636

757

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

637

758

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

638

759

760

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

761

__attribute__((warn_unused_result))

762

error_t raise_privileges(void){

763

error_t old_errno = errno;

764

error_t ret_errno = 0;

765

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

766

ret_errno = errno;

767

}

768

errno = old_errno;

769

return ret_errno;

770

}

771

772

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

773

__attribute__((warn_unused_result))

774

error_t raise_privileges_permanently(void){

775

error_t old_errno = errno;

776

error_t ret_errno = raise_privileges();

777

if(ret_errno != 0){

778

errno = old_errno;

779

return ret_errno;

780

}

781

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

782

ret_errno = errno;

783

}

784

errno = old_errno;

785

return ret_errno;

786

}

787

788

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

789

__attribute__((warn_unused_result))

790

error_t lower_privileges(void){

791

error_t old_errno = errno;

792

error_t ret_errno = 0;

793

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

794

ret_errno = errno;

795

}

796

errno = old_errno;

797

return ret_errno;

798

}

799

800

/* Lower privileges permanently */

801

__attribute__((warn_unused_result))

802

error_t lower_privileges_permanently(void){

803

error_t old_errno = errno;

804

error_t ret_errno = 0;

805

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

806

ret_errno = errno;

807

}

808

errno = old_errno;

809

return ret_errno;

810

}

811

812

/* Helper function to add_local_route() and delete_local_route() */

813

__attribute__((nonnull, warn_unused_result))

814

static bool add_delete_local_route(const bool add,

815

const char *address,

816

AvahiIfIndex if_index){

817

int ret;

818

char helper[] = "mandos-client-iprouteadddel";

819

char add_arg[] = "add";

820

char delete_arg[] = "delete";

821

char debug_flag[] = "--debug";

822

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

823

if(pluginhelperdir == NULL){

824

if(debug){

825

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

826

" variable not set; cannot run helper\n");

827

}

828

return false;

829

}

830

831

char interface[IF_NAMESIZE];

832

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

833

perror_plus("if_indextoname");

834

return false;

835

}

836

837

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

838

if(devnull == -1){

839

perror_plus("open(\"/dev/null\", O_RDONLY)");

840

return false;

841

}

842

pid_t pid = fork();

843

if(pid == 0){

844

/* Child */

845

/* Raise privileges */

846

errno = raise_privileges_permanently();

847

if(errno != 0){

848

perror_plus("Failed to raise privileges");

849

/* _exit(EX_NOPERM); */

850

} else {

851

/* Set group */

852

errno = 0;

853

ret = setgid(0);

854

if(ret == -1){

855

perror_plus("setgid");

856

_exit(EX_NOPERM);

857

}

858

/* Reset supplementary groups */

859

errno = 0;

860

ret = setgroups(0, NULL);

861

if(ret == -1){

862

perror_plus("setgroups");

863

_exit(EX_NOPERM);

864

}

865

}

866

ret = dup2(devnull, STDIN_FILENO);

867

if(ret == -1){

868

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

869

_exit(EX_OSERR);

870

}

871

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

872

if(ret == -1){

873

perror_plus("close");

874

_exit(EX_OSERR);

875

}

876

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

877

if(ret == -1){

878

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

879

_exit(EX_OSERR);

880

}

881

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

882

O_RDONLY

883

| O_DIRECTORY

884

| O_PATH

885

| O_CLOEXEC));

886

if(helperdir_fd == -1){

887

perror_plus("open");

888

_exit(EX_UNAVAILABLE);

889

}

890

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

891

helper, O_RDONLY));

892

if(helper_fd == -1){

893

perror_plus("openat");

894

_exit(EX_UNAVAILABLE);

895

}

896

TEMP_FAILURE_RETRY(close(helperdir_fd));

897

#ifdef __GNUC__

898

#pragma GCC diagnostic push

899

#pragma GCC diagnostic ignored "-Wcast-qual"

900

#endif

901

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

902

{ helper, add ? add_arg : delete_arg, (char *)address,

903

interface, debug ? debug_flag : NULL, NULL },

904

environ) == -1){

905

#ifdef __GNUC__

906

#pragma GCC diagnostic pop

907

#endif

908

perror_plus("fexecve");

909

_exit(EXIT_FAILURE);

910

}

911

}

912

if(pid == -1){

913

perror_plus("fork");

914

return false;

915

}

916

int status;

917

pid_t pret = -1;

918

errno = 0;

919

do {

920

pret = waitpid(pid, &status, 0);

921

if(pret == -1 and errno == EINTR and quit_now){

922

int errno_raising = 0;

923

if((errno = raise_privileges()) != 0){

924

errno_raising = errno;

925

perror_plus("Failed to raise privileges in order to"

926

" kill helper program");

927

}

928

if(kill(pid, SIGTERM) == -1){

929

perror_plus("kill");

930

}

931

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

932

perror_plus("Failed to lower privileges after killing"

933

" helper program");

934

}

935

return false;

936

}

937

} while(pret == -1 and errno == EINTR);

938

if(pret == -1){

939

perror_plus("waitpid");

940

return false;

941

}

942

if(WIFEXITED(status)){

943

if(WEXITSTATUS(status) != 0){

944

fprintf_plus(stderr, "Error: iprouteadddel exited"

945

" with status %d\n", WEXITSTATUS(status));

946

return false;

947

}

948

return true;

949

}

950

if(WIFSIGNALED(status)){

951

fprintf_plus(stderr, "Error: iprouteadddel died by"

952

" signal %d\n", WTERMSIG(status));

953

return false;

954

}

955

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

956

return false;

957

}

958

959

__attribute__((nonnull, warn_unused_result))

960

static bool add_local_route(const char *address,

961

AvahiIfIndex if_index){

962

if(debug){

963

fprintf_plus(stderr, "Adding route to %s\n", address);

964

}

965

return add_delete_local_route(true, address, if_index);

966

}

967

968

__attribute__((nonnull, warn_unused_result))

969

static bool delete_local_route(const char *address,

970

AvahiIfIndex if_index){

971

if(debug){

972

fprintf_plus(stderr, "Removing route to %s\n", address);

973

}

974

return add_delete_local_route(false, address, if_index);

975

}

976

639

977

/* Called when a Mandos server is found */

640

978

__attribute__((nonnull, warn_unused_result))

641

979

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

652

990

int retval = -1;

653

991

gnutls_session_t session;

654

992

int pf; /* Protocol family */

993

bool route_added = false;

655

994

656

995

errno = 0;

657

996

715

1054

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

716

1055

}

717

1056

718

tcp_sd = socket(pf, SOCK_STREAM, 0);

1057

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

719

1058

if(tcp_sd < 0){

720

1059

int e = errno;

721

1060

perror_plus("socket");

810

1149

goto mandos_end;

811

1150

}

812

1151

813

if(af == AF_INET6){

814

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

815

sizeof(struct sockaddr_in6));

816

} else {

817

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

818

sizeof(struct sockaddr_in));

819

}

820

if(ret < 0){

821

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

822

int e = errno;

823

perror_plus("connect");

824

errno = e;

825

}

826

goto mandos_end;

827

}

828

829

if(quit_now){

830

errno = EINTR;

831

goto mandos_end;

1152

while(true){

1153

if(af == AF_INET6){

1154

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

1155

sizeof(struct sockaddr_in6));

1156

} else {

1157

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

1158

sizeof(struct sockaddr_in));

1159

}

1160

if(ret < 0){

1161

if(errno == ENETUNREACH

1162

and if_index != AVAHI_IF_UNSPEC

1163

and connect_to == NULL

1164

and not route_added and

1165

((af == AF_INET6 and not

1166

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1167

&to)->sin6_addr)))

1168

or (af == AF_INET and

1169

/* Not a a IPv4LL address */

1170

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1171

& 0xFFFF0000L) != 0xA9FE0000L))){

1172

/* Work around Avahi bug - Avahi does not announce link-local

1173

addresses if it has a global address, so local hosts with

1174

*only* a link-local address (e.g. Mandos clients) cannot

1175

connect to a Mandos server announced by Avahi on a server

1176

host with a global address. Work around this by retrying

1177

with an explicit route added with the server's address.

1178

1179

Avahi bug reference:

1180

http://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1181

https://bugs.debian.org/587961

1182

*/

1183

if(debug){

1184

fprintf_plus(stderr, "Mandos server unreachable, trying"

1185

" direct route\n");

1186

}

1187

int e = errno;

1188

route_added = add_local_route(ip, if_index);

1189

if(route_added){

1190

continue;

1191

}

1192

errno = e;

1193

}

1194

if(errno != ECONNREFUSED or debug){

1195

int e = errno;

1196

perror_plus("connect");

1197

errno = e;

1198

}

1199

goto mandos_end;

1200

}

1201

1202

if(quit_now){

1203

errno = EINTR;

1204

goto mandos_end;

1205

}

1206

break;

832

1207

}

833

1208

834

1209

const char *out = mandos_protocol_version;

1017

1392

1018

1393

mandos_end:

1019

1394

{

1395

if(route_added){

1396

if(not delete_local_route(ip, if_index)){

1397

fprintf_plus(stderr, "Failed to delete local route to %s on"

1398

" interface %d", ip, if_index);

1399

}

1400

}

1020

1401

int e = errno;

1021

1402

free(decrypted_buffer);

1022

1403

free(buffer);

1062

1443

timed out */

1063

1444

1064

1445

if(quit_now){

1446

avahi_s_service_resolver_free(r);

1065

1447

return;

1066

1448

}

1067

1449

1333

1715

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

1334

1716

"abcdefghijklmnopqrstuvwxyz"

1335

1717

"0123456789"

1336

"_-");

1718

"_.-");

1337

1719

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

1338

1720

/* Contains non-allowed characters */

1339

1721

if(debug){

1343

1725

return 0;

1344

1726

}

1345

1727

1346

char *fullname = NULL;

1347

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

1348

if(ret < 0){

1349

perror_plus("asprintf");

1350

return 0;

1351

}

1352

1353

ret = stat(fullname, &st);

1728

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

1354

1729

if(ret == -1){

1355

1730

if(debug){

1356

1731

perror_plus("Could not stat hook");

1454

1829

}

1455

1830

}

1456

1831

1457

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

1458

__attribute__((warn_unused_result))

1459

error_t raise_privileges(void){

1460

error_t old_errno = errno;

1461

error_t ret_errno = 0;

1462

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

1463

ret_errno = errno;

1464

perror_plus("seteuid");

1465

}

1466

errno = old_errno;

1467

return ret_errno;

1468

}

1469

1470

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

1471

__attribute__((warn_unused_result))

1472

error_t raise_privileges_permanently(void){

1473

error_t old_errno = errno;

1474

error_t ret_errno = raise_privileges();

1475

if(ret_errno != 0){

1476

errno = old_errno;

1477

return ret_errno;

1478

}

1479

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

1480

ret_errno = errno;

1481

perror_plus("seteuid");

1482

}

1483

errno = old_errno;

1484

return ret_errno;

1485

}

1486

1487

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

1488

__attribute__((warn_unused_result))

1489

error_t lower_privileges(void){

1490

error_t old_errno = errno;

1491

error_t ret_errno = 0;

1492

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

1493

ret_errno = errno;

1494

perror_plus("seteuid");

1495

}

1496

errno = old_errno;

1497

return ret_errno;

1498

}

1499

1500

/* Lower privileges permanently */

1501

__attribute__((warn_unused_result))

1502

error_t lower_privileges_permanently(void){

1503

error_t old_errno = errno;

1504

error_t ret_errno = 0;

1505

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

1506

ret_errno = errno;

1507

perror_plus("setuid");

1508

}

1509

errno = old_errno;

1510

return ret_errno;

1511

}

1512

1513

1832

__attribute__((nonnull))

1514

1833

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

1515

1834

const float delay){

1516

struct dirent **direntries;

1517

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

1518

alphasort);

1835

struct dirent **direntries = NULL;

1836

if(hookdir_fd == -1){

1837

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1838

| O_CLOEXEC);

1839

if(hookdir_fd == -1){

1840

if(errno == ENOENT){

1841

if(debug){

1842

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

1843

" found\n", hookdir);

1844

}

1845

} else {

1846

perror_plus("open");

1847

}

1848

return;

1849

}

1850

}

1851

#ifdef __GLIBC__

1852

#if __GLIBC_PREREQ(2, 15)

1853

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

1854

runnable_hook, alphasort);

1855

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

1856

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

1857

alphasort);

1858

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

1859

#else /* not __GLIBC__ */

1860

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

1861

alphasort);

1862

#endif /* not __GLIBC__ */

1519

1863

if(numhooks == -1){

1520

if(errno == ENOENT){

1521

if(debug){

1522

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

1523

" found\n", hookdir);

1524

}

1525

} else {

1526

perror_plus("scandir");

1864

perror_plus("scandir");

1865

return;

1866

}

1867

struct dirent *direntry;

1868

int ret;

1869

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

1870

if(devnull == -1){

1871

perror_plus("open(\"/dev/null\", O_RDONLY)");

1872

return;

1873

}

1874

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

1875

direntry = direntries[i];

1876

if(debug){

1877

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

1878

direntry->d_name);

1527

1879

}

1528

} else {

1529

struct dirent *direntry;

1530

int ret;

1531

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

1532

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

1533

direntry = direntries[i];

1534

char *fullname = NULL;

1535

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

1536

if(ret < 0){

1880

pid_t hook_pid = fork();

1881

if(hook_pid == 0){

1882

/* Child */

1883

/* Raise privileges */

1884

errno = raise_privileges_permanently();

1885

if(errno != 0){

1886

perror_plus("Failed to raise privileges");

1887

_exit(EX_NOPERM);

1888

}

1889

/* Set group */

1890

errno = 0;

1891

ret = setgid(0);

1892

if(ret == -1){

1893

perror_plus("setgid");

1894

_exit(EX_NOPERM);

1895

}

1896

/* Reset supplementary groups */

1897

errno = 0;

1898

ret = setgroups(0, NULL);

1899

if(ret == -1){

1900

perror_plus("setgroups");

1901

_exit(EX_NOPERM);

1902

}

1903

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

1904

if(ret == -1){

1905

perror_plus("setenv");

1906

_exit(EX_OSERR);

1907

}

1908

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

1909

if(ret == -1){

1910

perror_plus("setenv");

1911

_exit(EX_OSERR);

1912

}

1913

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

1914

if(ret == -1){

1915

perror_plus("setenv");

1916

_exit(EX_OSERR);

1917

}

1918

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

1919

if(ret == -1){

1920

perror_plus("setenv");

1921

_exit(EX_OSERR);

1922

}

1923

char *delaystring;

1924

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

1925

if(ret == -1){

1537

1926

perror_plus("asprintf");

1538

continue;

1539

}

1540

if(debug){

1541

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

1542

direntry->d_name);

1543

}

1544

pid_t hook_pid = fork();

1545

if(hook_pid == 0){

1546

/* Child */

1547

/* Raise privileges */

1548

if(raise_privileges_permanently() != 0){

1549

perror_plus("Failed to raise privileges");

1550

_exit(EX_NOPERM);

1551

}

1552

/* Set group */

1553

errno = 0;

1554

ret = setgid(0);

1555

if(ret == -1){

1556

perror_plus("setgid");

1557

_exit(EX_NOPERM);

1558

}

1559

/* Reset supplementary groups */

1560

errno = 0;

1561

ret = setgroups(0, NULL);

1562

if(ret == -1){

1563

perror_plus("setgroups");

1564

_exit(EX_NOPERM);

1565

}

1566

ret = dup2(devnull, STDIN_FILENO);

1567

if(ret == -1){

1568

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

1569

_exit(EX_OSERR);

1570

}

1571

ret = close(devnull);

1572

if(ret == -1){

1573

perror_plus("close");

1574

_exit(EX_OSERR);

1575

}

1576

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1577

if(ret == -1){

1578

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

1579

_exit(EX_OSERR);

1580

}

1581

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

1582

if(ret == -1){

1583

perror_plus("setenv");

1584

_exit(EX_OSERR);

1585

}

1586

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

1587

if(ret == -1){

1588

perror_plus("setenv");

1589

_exit(EX_OSERR);

1590

}

1591

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

1592

if(ret == -1){

1593

perror_plus("setenv");

1594

_exit(EX_OSERR);

1595

}

1596

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

1597

if(ret == -1){

1598

perror_plus("setenv");

1599

_exit(EX_OSERR);

1600

}

1601

char *delaystring;

1602

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

1603

if(ret == -1){

1604

perror_plus("asprintf");

1605

_exit(EX_OSERR);

1606

}

1607

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

1608

if(ret == -1){

1609

free(delaystring);

1610

perror_plus("setenv");

1611

_exit(EX_OSERR);

1612

}

1927

_exit(EX_OSERR);

1928

}

1929

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

1930

if(ret == -1){

1613

1931

free(delaystring);

1614

if(connect_to != NULL){

1615

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

1616

if(ret == -1){

1617

perror_plus("setenv");

1618

_exit(EX_OSERR);

1619

}

1620

}

1621

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

1622

perror_plus("execl");

1623

_exit(EXIT_FAILURE);

1624

}

1932

perror_plus("setenv");

1933

_exit(EX_OSERR);

1934

}

1935

free(delaystring);

1936

if(connect_to != NULL){

1937

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

1938

if(ret == -1){

1939

perror_plus("setenv");

1940

_exit(EX_OSERR);

1941

}

1942

}

1943

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

1944

direntry->d_name,

1945

O_RDONLY));

1946

if(hook_fd == -1){

1947

perror_plus("openat");

1948

_exit(EXIT_FAILURE);

1949

}

1950

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

1951

perror_plus("close");

1952

_exit(EXIT_FAILURE);

1953

}

1954

ret = dup2(devnull, STDIN_FILENO);

1955

if(ret == -1){

1956

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

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("close");

1962

_exit(EX_OSERR);

1963

}

1964

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1965

if(ret == -1){

1966

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

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

environ) == -1){

1971

perror_plus("fexecve");

1972

_exit(EXIT_FAILURE);

1973

}

1974

} else {

1975

if(hook_pid == -1){

1976

perror_plus("fork");

1977

free(direntry);

1978

continue;

1979

}

1980

int status;

1981

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

1982

perror_plus("waitpid");

1983

free(direntry);

1984

continue;

1985

}

1986

if(WIFEXITED(status)){

1987

if(WEXITSTATUS(status) != 0){

1988

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

1989

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

1990

WEXITSTATUS(status));

1991

free(direntry);

1992

continue;

1993

}

1994

} else if(WIFSIGNALED(status)){

1995

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

1996

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

1997

WTERMSIG(status));

1998

free(direntry);

1999

continue;

1625

2000

} else {

1626

int status;

1627

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

1628

perror_plus("waitpid");

1629

free(fullname);

1630

continue;

1631

}

1632

if(WIFEXITED(status)){

1633

if(WEXITSTATUS(status) != 0){

1634

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

1635

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

1636

WEXITSTATUS(status));

1637

free(fullname);

1638

continue;

1639

}

1640

} else if(WIFSIGNALED(status)){

1641

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

1642

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

1643

WTERMSIG(status));

1644

free(fullname);

1645

continue;

1646

} else {

1647

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

1648

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

1649

free(fullname);

1650

continue;

1651

}

1652

}

1653

free(fullname);

1654

if(debug){

1655

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

1656

direntry->d_name);

1657

}

1658

}

1659

close(devnull);

1660

}

2001

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

2002

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

2003

free(direntry);

2004

continue;

2005

}

2006

}

2007

if(debug){

2008

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

2009

direntry->d_name);

2010

}

2011

free(direntry);

2012

}

2013

free(direntries);

2014

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

2015

perror_plus("close");

2016

} else {

2017

hookdir_fd = -1;

2018

}

2019

close(devnull);

1661

2020

}

1662

2021

1663

2022

__attribute__((nonnull, warn_unused_result))

1713

2072

1714

2073

/* Raise privileges */

1715

2074

ret_errno = raise_privileges();

2075

if(ret_errno != 0){

2076

errno = ret_errno;

2077

perror_plus("Failed to raise privileges");

2078

}

2079

2080

#ifdef __linux__

2081

int ret_linux;

1716

2082

bool restore_loglevel = false;

1717

if(ret_errno != 0){

1718

perror_plus("Failed to raise privileges");

1719

}

1720

#ifdef __linux__

1721

int ret_linux;

1722

2083

if(ret_errno == 0){

1723

2084

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1724

2085

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

1822

2183

/* Raise privileges */

1823

2184

ret_errno = raise_privileges();

1824

2185

if(ret_errno != 0){

2186

errno = ret_errno;

1825

2187

perror_plus("Failed to raise privileges");

1826

2188

}

2189

1827

2190

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

1828

2191

ioctl_errno = errno;

1829

2192

1859

2222

}

1860

2223

1861

2224

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

1862

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

2225

mandos_context mc = { .server = NULL, .dh_bits = 0,

1863

2226

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

1864

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

2227

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

1865

2228

.interfaces = NULL, .interfaces_size = 0 };

1866

2229

AvahiSServiceBrowser *sb = NULL;

1867

2230

error_t ret_errno;

1871

2234

int exitcode = EXIT_SUCCESS;

1872

2235

char *interfaces_to_take_down = NULL;

1873

2236

size_t interfaces_to_take_down_size = 0;

1874

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

1875

bool tempdir_created = false;

2237

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

2238

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

2239

char *tempdir = NULL;

1876

2240

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1877

2241

const char *seckey = PATHDIR "/" SECKEY;

1878

2242

const char *pubkey = PATHDIR "/" PUBKEY;

2055

2419

goto end;

2056

2420

}

2057

2421

}

2058

2422

2059

2423

{

2060

2424

/* Work around Debian bug #633582:

2061

2425

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

2088

2452

TEMP_FAILURE_RETRY(close(seckey_fd));

2089

2453

}

2090

2454

}

2091

2455

2092

2456

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2093

2457

int pubkey_fd = open(pubkey, O_RDONLY);

2094

2458

if(pubkey_fd == -1){

2109

2473

TEMP_FAILURE_RETRY(close(pubkey_fd));

2110

2474

}

2111

2475

}

2112

2476

2113

2477

/* Lower privileges */

2114

2478

ret_errno = lower_privileges();

2115

2479

if(ret_errno != 0){

2232

2596

2233

2597

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

2234

2598

if(mc.interfaces == NULL){

2235

struct dirent **direntries;

2599

struct dirent **direntries = NULL;

2236

2600

/* Look for any good interfaces */

2237

2601

ret = scandir(sys_class_net, &direntries, good_interface,

2238

2602

alphasort);

2244

2608

if(ret_errno != 0){

2245

2609

errno = ret_errno;

2246

2610

perror_plus("argz_add");

2611

free(direntries[i]);

2247

2612

continue;

2248

2613

}

2249

2614

if(debug){

2250

2615

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

2251

2616

direntries[i]->d_name);

2252

2617

}

2618

free(direntries[i]);

2253

2619

}

2254

2620

free(direntries);

2255

2621

} else {

2256

free(direntries);

2622

if(ret == 0){

2623

free(direntries);

2624

}

2257

2625

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

2258

2626

exitcode = EXIT_FAILURE;

2259

2627

goto end;

2327

2695

goto end;

2328

2696

}

2329

2697

2330

if(mkdtemp(tempdir) == NULL){

2698

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

2699

tempdir = mkdtemp(run_tempdir);

2700

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

2701

if(debug){

2702

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

2703

run_tempdir, old_tempdir);

2704

}

2705

tempdir = mkdtemp(old_tempdir);

2706

}

2707

if(tempdir == NULL){

2331

2708

perror_plus("mkdtemp");

2332

2709

goto end;

2333

2710

}

2334

tempdir_created = true;

2335

2711

2336

2712

if(quit_now){

2337

2713

goto end;

2473

2849

if(debug){

2474

2850

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

2475

2851

}

2476

2852

2477

2853

ret = avahi_loop_with_timeout(simple_poll,

2478

2854

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

2479

2855

if(debug){

2515

2891

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

2516

2892

while(mc.current_server != NULL){

2517

2893

server *next = mc.current_server->next;

2894

#ifdef __GNUC__

2895

#pragma GCC diagnostic push

2896

#pragma GCC diagnostic ignored "-Wcast-qual"

2897

#endif

2898

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

2899

#ifdef __GNUC__

2900

#pragma GCC diagnostic pop

2901

#endif

2518

2902

free(mc.current_server);

2519

2903

mc.current_server = next;

2520

2904

}

2524

2908

{

2525

2909

ret_errno = raise_privileges();

2526

2910

if(ret_errno != 0){

2911

errno = ret_errno;

2527

2912

perror_plus("Failed to raise privileges");

2528

2913

} else {

2529

2914

2549

2934

}

2550

2935

}

2551

2936

}

2937

2552

2938

ret_errno = lower_privileges_permanently();

2553

2939

if(ret_errno != 0){

2940

errno = ret_errno;

2554

2941

perror_plus("Failed to lower privileges permanently");

2555

2942

}

2556

2943

}

2559

2946

free(interfaces_hooks);

2560

2947

2561

2948

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

2562

if(tempdir_created){

2949

if(tempdir != NULL){

2563

2950

struct dirent **direntries = NULL;

2564

struct dirent *direntry = NULL;

2565

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

2566

alphasort);

2567

if(numentries > 0){

2568

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

2569

direntry = direntries[i];

2570

char *fullname = NULL;

2571

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

2572

direntry->d_name);

2573

if(ret < 0){

2574

perror_plus("asprintf");

2575

continue;

2576

}

2577

ret = remove(fullname);

2578

if(ret == -1){

2579

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

2580

strerror(errno));

2581

}

2582

free(fullname);

2951

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

2952

| O_NOFOLLOW

2953

| O_DIRECTORY

2954

| O_PATH));

2955

if(tempdir_fd == -1){

2956

perror_plus("open");

2957

} else {

2958

#ifdef __GLIBC__

2959

#if __GLIBC_PREREQ(2, 15)

2960

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

2961

notdotentries, alphasort);

2962

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

2963

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

2964

alphasort);

2965

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

2966

#else /* not __GLIBC__ */

2967

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

2968

alphasort);

2969

#endif /* not __GLIBC__ */

2970

if(numentries >= 0){

2971

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

2972

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

2973

if(ret == -1){

2974

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

2975

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

2976

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

2977

}

2978

free(direntries[i]);

2979

}

2980

2981

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

2982

free(direntries);

2983

if(numentries == -1){

2984

perror_plus("scandir");

2985

}

2986

ret = rmdir(tempdir);

2987

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

2988

perror_plus("rmdir");

2989

}

2583

2990

}

2584

}

2585

2586

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

2587

free(direntries);

2588

if(numentries == -1){

2589

perror_plus("scandir");

2590

}

2591

ret = rmdir(tempdir);

2592

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

2593

perror_plus("rmdir");

2991

TEMP_FAILURE_RETRY(close(tempdir_fd));

2594

2992

}

2595

2993

}

2596

2994