/mandos/trunk : revision 766

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

183

185

perror(print_text);

184

186

}

185

187

186

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

188

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

187

189

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

188

190

va_list ap;

189

191

va_start (ap, format);

198

200

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

199

201

* "buffer_length" is how much is already used.

200

202

*/

203

__attribute__((nonnull, warn_unused_result))

201

204

size_t incbuffer(char **buffer, size_t buffer_length,

202

205

size_t buffer_capacity){

203

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

216

219

}

217

220

218

221

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

222

__attribute__((nonnull, warn_unused_result))

219

223

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

220

224

int af, server **current_server){

221

225

int ret;

230

234

.af = af };

231

235

if(new_server->ip == NULL){

232

236

perror_plus("strdup");

237

free(new_server);

233

238

return false;

234

239

}

235

240

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

236

241

if(ret == -1){

237

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);

238

252

return false;

239

253

}

240

254

/* Special case of first server */

242

256

new_server->next = new_server;

243

257

new_server->prev = new_server;

244

258

*current_server = new_server;

245

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

246

259

} else {

260

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

247

261

new_server->next = *current_server;

248

262

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

249

263

new_server->prev->next = new_server;

255

269

/*

256

270

* Initialize GPGME.

257

271

*/

258

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

259

const char *tempdir, mandos_context *mc){

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

260

277

gpgme_error_t rc;

261

278

gpgme_engine_info_t engine_info;

262

279

263

280

/*

264

281

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

265

282

*/

266

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

267

284

int ret;

268

285

int fd;

269

286

gpgme_data_t pgp_data;

350

367

* Decrypt OpenPGP data.

351

368

* Returns -1 on error

352

369

*/

370

__attribute__((nonnull, warn_unused_result))

353

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

354

372

size_t crypto_size,

355

373

char **plaintext,

475

493

return plaintext_length;

476

494

}

477

495

478

static const char * safer_gnutls_strerror(int value){

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

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

479

505

const char *ret = gnutls_strerror(value);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

506

return safe_string(ret);

483

507

}

484

508

485

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

486

511

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

487

512

const char* string){

488

513

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

489

514

}

490

515

516

__attribute__((nonnull, warn_unused_result))

491

517

static int init_gnutls_global(const char *pubkeyfilename,

492

518

const char *seckeyfilename,

519

const char *dhparamsfilename,

493

520

mandos_context *mc){

494

521

int ret;

522

unsigned int uret;

495

523

496

524

if(debug){

497

525

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

548

576

safer_gnutls_strerror(ret));

549

577

goto globalfail;

550

578

}

551

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

552

if(ret != GNUTLS_E_SUCCESS){

553

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

554

safer_gnutls_strerror(ret));

555

goto globalfail;

556

}

557

579

/* If a Diffie-Hellman parameters file was given, try to use it */

580

if(dhparamsfilename != NULL){

581

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

582

do {

583

int dhpfile = open(dhparamsfilename, O_RDONLY);

584

if(dhpfile == -1){

585

perror_plus("open");

586

dhparamsfilename = NULL;

587

break;

588

}

589

size_t params_capacity = 0;

590

while(true){

591

params_capacity = incbuffer((char **)&params.data,

592

(size_t)params.size,

593

(size_t)params_capacity);

594

if(params_capacity == 0){

595

perror_plus("incbuffer");

596

free(params.data);

597

params.data = NULL;

598

dhparamsfilename = NULL;

599

break;

600

}

601

ssize_t bytes_read = read(dhpfile,

602

params.data + params.size,

603

BUFFER_SIZE);

604

/* EOF */

605

if(bytes_read == 0){

606

break;

607

}

608

/* check bytes_read for failure */

609

if(bytes_read < 0){

610

perror_plus("read");

611

free(params.data);

612

params.data = NULL;

613

dhparamsfilename = NULL;

614

break;

615

}

616

params.size += (unsigned int)bytes_read;

617

}

618

if(params.data == NULL){

619

dhparamsfilename = NULL;

620

}

621

if(dhparamsfilename == NULL){

622

break;

623

}

624

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

625

GNUTLS_X509_FMT_PEM);

626

if(ret != GNUTLS_E_SUCCESS){

627

fprintf_plus(stderr, "Failed to parse DH parameters in file"

628

" \"%s\": %s\n", dhparamsfilename,

629

safer_gnutls_strerror(ret));

630

dhparamsfilename = NULL;

631

}

632

} while(false);

633

}

634

if(dhparamsfilename == NULL){

635

if(mc->dh_bits == 0){

636

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

637

/* Try to read the private key file */

638

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

639

do {

640

int secfile = open(seckeyfilename, O_RDONLY);

641

if(secfile == -1){

642

perror_plus("open");

643

break;

644

}

645

size_t buffer_capacity = 0;

646

while(true){

647

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

648

(size_t)buffer.size,

649

(size_t)buffer_capacity);

650

if(buffer_capacity == 0){

651

perror_plus("incbuffer");

652

free(buffer.data);

653

buffer.data = NULL;

654

break;

655

}

656

ssize_t bytes_read = read(secfile,

657

buffer.data + buffer.size,

658

BUFFER_SIZE);

659

/* EOF */

660

if(bytes_read == 0){

661

break;

662

}

663

/* check bytes_read for failure */

664

if(bytes_read < 0){

665

perror_plus("read");

666

free(buffer.data);

667

buffer.data = NULL;

668

break;

669

}

670

buffer.size += (unsigned int)bytes_read;

671

}

672

close(secfile);

673

} while(false);

674

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

675

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

676

if(buffer.data != NULL){

677

{

678

gnutls_openpgp_privkey_t privkey = NULL;

679

ret = gnutls_openpgp_privkey_init(&privkey);

680

if(ret != GNUTLS_E_SUCCESS){

681

fprintf_plus(stderr, "Error initializing OpenPGP key"

682

" structure: %s",

683

safer_gnutls_strerror(ret));

684

free(buffer.data);

685

buffer.data = NULL;

686

} else {

687

ret = gnutls_openpgp_privkey_import

688

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

689

if(ret != GNUTLS_E_SUCCESS){

690

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

691

safer_gnutls_strerror(ret));

692

privkey = NULL;

693

}

694

free(buffer.data);

695

buffer.data = NULL;

696

if(privkey != NULL){

697

/* Use private key to suggest an appropriate

698

sec_param */

699

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

700

gnutls_openpgp_privkey_deinit(privkey);

701

if(debug){

702

fprintf_plus(stderr, "This OpenPGP key implies using"

703

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

704

safe_string(gnutls_sec_param_get_name

705

(sec_param)));

706

}

707

}

708

}

709

}

710

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

711

/* Err on the side of caution */

712

sec_param = GNUTLS_SEC_PARAM_ULTRA;

713

if(debug){

714

fprintf_plus(stderr, "Falling back to security parameter"

715

" \"%s\"\n",

716

safe_string(gnutls_sec_param_get_name

717

(sec_param)));

718

}

719

}

720

}

721

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

722

if(uret != 0){

723

mc->dh_bits = uret;

724

if(debug){

725

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

726

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

727

safe_string(gnutls_sec_param_get_name

728

(sec_param)),

729

mc->dh_bits);

730

}

731

} else {

732

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

733

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

734

safe_string(gnutls_sec_param_get_name

735

(sec_param)),

736

safer_gnutls_strerror(ret));

737

goto globalfail;

738

}

739

} else if(debug){

740

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

741

mc->dh_bits);

742

}

743

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

744

if(ret != GNUTLS_E_SUCCESS){

745

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

746

" bits): %s\n", mc->dh_bits,

747

safer_gnutls_strerror(ret));

748

goto globalfail;

749

}

750

}

558

751

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

559

752

560

753

return 0;

567

760

return -1;

568

761

}

569

762

763

__attribute__((nonnull, warn_unused_result))

570

764

static int init_gnutls_session(gnutls_session_t *session,

571

765

mandos_context *mc){

572

766

int ret;

619

813

/* ignore client certificate if any. */

620

814

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

621

815

622

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

623

624

816

return 0;

625

817

}

626

818

628

820

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

629

821

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

630

822

823

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

824

__attribute__((warn_unused_result))

825

error_t raise_privileges(void){

826

error_t old_errno = errno;

827

error_t ret_errno = 0;

828

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

829

ret_errno = errno;

830

}

831

errno = old_errno;

832

return ret_errno;

833

}

834

835

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

836

__attribute__((warn_unused_result))

837

error_t raise_privileges_permanently(void){

838

error_t old_errno = errno;

839

error_t ret_errno = raise_privileges();

840

if(ret_errno != 0){

841

errno = old_errno;

842

return ret_errno;

843

}

844

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

845

ret_errno = errno;

846

}

847

errno = old_errno;

848

return ret_errno;

849

}

850

851

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

852

__attribute__((warn_unused_result))

853

error_t lower_privileges(void){

854

error_t old_errno = errno;

855

error_t ret_errno = 0;

856

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

857

ret_errno = errno;

858

}

859

errno = old_errno;

860

return ret_errno;

861

}

862

863

/* Lower privileges permanently */

864

__attribute__((warn_unused_result))

865

error_t lower_privileges_permanently(void){

866

error_t old_errno = errno;

867

error_t ret_errno = 0;

868

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

869

ret_errno = errno;

870

}

871

errno = old_errno;

872

return ret_errno;

873

}

874

875

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

876

__attribute__((nonnull, warn_unused_result))

877

static bool add_delete_local_route(const bool add,

878

const char *address,

879

AvahiIfIndex if_index){

880

int ret;

881

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

882

char add_arg[] = "add";

883

char delete_arg[] = "delete";

884

char debug_flag[] = "--debug";

885

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

886

if(pluginhelperdir == NULL){

887

if(debug){

888

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

889

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

890

}

891

return false;

892

}

893

894

char interface[IF_NAMESIZE];

895

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

896

perror_plus("if_indextoname");

897

return false;

898

}

899

900

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

901

if(devnull == -1){

902

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

903

return false;

904

}

905

pid_t pid = fork();

906

if(pid == 0){

907

/* Child */

908

/* Raise privileges */

909

errno = raise_privileges_permanently();

910

if(errno != 0){

911

perror_plus("Failed to raise privileges");

912

/* _exit(EX_NOPERM); */

913

} else {

914

/* Set group */

915

errno = 0;

916

ret = setgid(0);

917

if(ret == -1){

918

perror_plus("setgid");

919

_exit(EX_NOPERM);

920

}

921

/* Reset supplementary groups */

922

errno = 0;

923

ret = setgroups(0, NULL);

924

if(ret == -1){

925

perror_plus("setgroups");

926

_exit(EX_NOPERM);

927

}

928

}

929

ret = dup2(devnull, STDIN_FILENO);

930

if(ret == -1){

931

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

932

_exit(EX_OSERR);

933

}

934

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

935

if(ret == -1){

936

perror_plus("close");

937

_exit(EX_OSERR);

938

}

939

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

940

if(ret == -1){

941

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

942

_exit(EX_OSERR);

943

}

944

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

945

O_RDONLY

946

| O_DIRECTORY

947

| O_PATH

948

| O_CLOEXEC));

949

if(helperdir_fd == -1){

950

perror_plus("open");

951

_exit(EX_UNAVAILABLE);

952

}

953

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

954

helper, O_RDONLY));

955

if(helper_fd == -1){

956

perror_plus("openat");

957

_exit(EX_UNAVAILABLE);

958

}

959

TEMP_FAILURE_RETRY(close(helperdir_fd));

960

#ifdef __GNUC__

961

#pragma GCC diagnostic push

962

#pragma GCC diagnostic ignored "-Wcast-qual"

963

#endif

964

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

965

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

966

interface, debug ? debug_flag : NULL, NULL },

967

environ) == -1){

968

#ifdef __GNUC__

969

#pragma GCC diagnostic pop

970

#endif

971

perror_plus("fexecve");

972

_exit(EXIT_FAILURE);

973

}

974

}

975

if(pid == -1){

976

perror_plus("fork");

977

return false;

978

}

979

int status;

980

pid_t pret = -1;

981

errno = 0;

982

do {

983

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

984

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

985

int errno_raising = 0;

986

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

987

errno_raising = errno;

988

perror_plus("Failed to raise privileges in order to"

989

" kill helper program");

990

}

991

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

992

perror_plus("kill");

993

}

994

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

995

perror_plus("Failed to lower privileges after killing"

996

" helper program");

997

}

998

return false;

999

}

1000

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

1001

if(pret == -1){

1002

perror_plus("waitpid");

1003

return false;

1004

}

1005

if(WIFEXITED(status)){

1006

if(WEXITSTATUS(status) != 0){

1007

fprintf_plus(stderr, "Error: iprouteadddel exited"

1008

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

1009

return false;

1010

}

1011

return true;

1012

}

1013

if(WIFSIGNALED(status)){

1014

fprintf_plus(stderr, "Error: iprouteadddel died by"

1015

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

1016

return false;

1017

}

1018

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

1019

return false;

1020

}

1021

1022

__attribute__((nonnull, warn_unused_result))

1023

static bool add_local_route(const char *address,

1024

AvahiIfIndex if_index){

1025

if(debug){

1026

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

1027

}

1028

return add_delete_local_route(true, address, if_index);

1029

}

1030

1031

__attribute__((nonnull, warn_unused_result))

1032

static bool delete_local_route(const char *address,

1033

AvahiIfIndex if_index){

1034

if(debug){

1035

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

1036

}

1037

return add_delete_local_route(false, address, if_index);

1038

}

1039

631

1040

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

632

1042

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

633

1043

AvahiIfIndex if_index,

634

1044

int af, mandos_context *mc){

643

1053

int retval = -1;

644

1054

gnutls_session_t session;

645

1055

int pf; /* Protocol family */

1056

bool route_added = false;

646

1057

647

1058

errno = 0;

648

1059

706

1117

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

707

1118

}

708

1119

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1120

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

710

1121

if(tcp_sd < 0){

711

1122

int e = errno;

712

1123

perror_plus("socket");

740

1151

goto mandos_end;

741

1152

}

742

1153

if(af == AF_INET6){

743

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

1154

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

744

1155

if(IN6_IS_ADDR_LINKLOCAL

745

1156

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

746

1157

if(if_index == AVAHI_IF_UNSPEC){

801

1212

goto mandos_end;

802

1213

}

803

1214

804

if(af == AF_INET6){

805

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

806

sizeof(struct sockaddr_in6));

807

} else {

808

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

809

sizeof(struct sockaddr_in));

810

}

811

if(ret < 0){

812

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

813

int e = errno;

814

perror_plus("connect");

815

errno = e;

816

}

817

goto mandos_end;

818

}

819

820

if(quit_now){

821

errno = EINTR;

822

goto mandos_end;

1215

while(true){

1216

if(af == AF_INET6){

1217

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

1218

sizeof(struct sockaddr_in6));

1219

} else {

1220

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

1221

sizeof(struct sockaddr_in));

1222

}

1223

if(ret < 0){

1224

if(errno == ENETUNREACH

1225

and if_index != AVAHI_IF_UNSPEC

1226

and connect_to == NULL

1227

and not route_added and

1228

((af == AF_INET6 and not

1229

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1230

&to)->sin6_addr)))

1231

or (af == AF_INET and

1232

/* Not a a IPv4LL address */

1233

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

1234

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

1235

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

1236

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

1237

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

1238

connect to a Mandos server announced by Avahi on a server

1239

host with a global address. Work around this by retrying

1240

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

1241

1242

Avahi bug reference:

1243

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

1244

https://bugs.debian.org/587961

1245

*/

1246

if(debug){

1247

fprintf_plus(stderr, "Mandos server unreachable, trying"

1248

" direct route\n");

1249

}

1250

int e = errno;

1251

route_added = add_local_route(ip, if_index);

1252

if(route_added){

1253

continue;

1254

}

1255

errno = e;

1256

}

1257

if(errno != ECONNREFUSED or debug){

1258

int e = errno;

1259

perror_plus("connect");

1260

errno = e;

1261

}

1262

goto mandos_end;

1263

}

1264

1265

if(quit_now){

1266

errno = EINTR;

1267

goto mandos_end;

1268

}

1269

break;

823

1270

}

824

1271

825

1272

const char *out = mandos_protocol_version;

1008

1455

1009

1456

mandos_end:

1010

1457

{

1458

if(route_added){

1459

if(not delete_local_route(ip, if_index)){

1460

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

1461

" interface %d", ip, if_index);

1462

}

1463

}

1011

1464

int e = errno;

1012

1465

free(decrypted_buffer);

1013

1466

free(buffer);

1030

1483

return retval;

1031

1484

}

1032

1485

1486

__attribute__((nonnull))

1033

1487

static void resolve_callback(AvahiSServiceResolver *r,

1034

1488

AvahiIfIndex interface,

1035

1489

AvahiProtocol proto,

1043

1497

AVAHI_GCC_UNUSED AvahiStringList *txt,

1044

1498

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1045

1499

flags,

1046

void* mc){

1500

void *mc){

1047

1501

if(r == NULL){

1048

1502

return;

1049

1503

}

1052

1506

timed out */

1053

1507

1054

1508

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1055

1510

return;

1056

1511

}

1057

1512

1102

1557

const char *domain,

1103

1558

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1104

1559

flags,

1105

void* mc){

1560

void *mc){

1106

1561

if(b == NULL){

1107

1562

return;

1108

1563

}

1168

1623

errno = old_errno;

1169

1624

}

1170

1625

1626

__attribute__((nonnull, warn_unused_result))

1171

1627

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

1172

1628

int ret;

1173

1629

error_t ret_errno;

1192

1648

return true;

1193

1649

}

1194

1650

1651

__attribute__((nonnull, warn_unused_result))

1195

1652

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

1196

1653

1197

1654

/* Reject the loopback device */

1239

1696

* corresponds to an acceptable network device.

1240

1697

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

1241

1698

*/

1699

__attribute__((nonnull, warn_unused_result))

1242

1700

int good_interface(const struct dirent *if_entry){

1243

1701

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

1244

1702

return 0;

1262

1720

/*

1263

1721

* This function determines if a network interface is up.

1264

1722

*/

1723

__attribute__((nonnull, warn_unused_result))

1265

1724

bool interface_is_up(const char *interface){

1266

1725

struct ifreq ifr;

1267

1726

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

1278

1737

/*

1279

1738

* This function determines if a network interface is running

1280

1739

*/

1740

__attribute__((nonnull, warn_unused_result))

1281

1741

bool interface_is_running(const char *interface){

1282

1742

struct ifreq ifr;

1283

1743

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

1291

1751

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

1292

1752

}

1293

1753

1754

__attribute__((nonnull, pure, warn_unused_result))

1294

1755

int notdotentries(const struct dirent *direntry){

1295

1756

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

1296

1757

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

1303

1764

}

1304

1765

1305

1766

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

1767

__attribute__((nonnull, warn_unused_result))

1306

1768

int runnable_hook(const struct dirent *direntry){

1307

1769

int ret;

1308

1770

size_t sret;

1316

1778

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

1317

1779

"abcdefghijklmnopqrstuvwxyz"

1318

1780

"0123456789"

1319

"_-");

1781

"_.-");

1320

1782

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

1321

1783

/* Contains non-allowed characters */

1322

1784

if(debug){

1326

1788

return 0;

1327

1789

}

1328

1790

1329

char *fullname = NULL;

1330

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

1331

if(ret < 0){

1332

perror_plus("asprintf");

1333

return 0;

1334

}

1335

1336

ret = stat(fullname, &st);

1791

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

1337

1792

if(ret == -1){

1338

1793

if(debug){

1339

1794

perror_plus("Could not stat hook");

1363

1818

return 1;

1364

1819

}

1365

1820

1821

__attribute__((nonnull, warn_unused_result))

1366

1822

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1367

1823

mandos_context *mc){

1368

1824

int ret;

1372

1828

1373

1829

while(true){

1374

1830

if(mc->current_server == NULL){

1375

if (debug){

1831

if(debug){

1376

1832

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

1377

1833

" No timeout!\n");

1378

1834

}

1379

1835

ret = avahi_simple_poll_iterate(s, -1);

1380

1836

} else {

1381

if (debug){

1837

if(debug){

1382

1838

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

1383

1839

" it, or wait\n");

1384

1840

}

1401

1857

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

1402

1858

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

1403

1859

1404

if (debug){

1860

if(debug){

1405

1861

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

1406

1862

block_time);

1407

1863

}

1429

1885

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

1430

1886

}

1431

1887

if(ret != 0){

1432

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

1888

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

1433

1889

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

1434

1890

}

1435

1891

}

1436

1892

}

1437

1893

}

1438

1894

1439

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

1440

error_t raise_privileges(void){

1441

error_t old_errno = errno;

1442

error_t ret_errno = 0;

1443

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

1444

ret_errno = errno;

1445

perror_plus("seteuid");

1446

}

1447

errno = old_errno;

1448

return ret_errno;

1449

}

1450

1451

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

1452

error_t raise_privileges_permanently(void){

1453

error_t old_errno = errno;

1454

error_t ret_errno = raise_privileges();

1455

if(ret_errno != 0){

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

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

1460

ret_errno = errno;

1461

perror_plus("seteuid");

1462

}

1463

errno = old_errno;

1464

return ret_errno;

1465

}

1466

1467

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

1468

error_t lower_privileges(void){

1469

error_t old_errno = errno;

1470

error_t ret_errno = 0;

1471

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

1472

ret_errno = errno;

1473

perror_plus("seteuid");

1474

}

1475

errno = old_errno;

1476

return ret_errno;

1477

}

1478

1479

/* Lower privileges permanently */

1480

error_t lower_privileges_permanently(void){

1481

error_t old_errno = errno;

1482

error_t ret_errno = 0;

1483

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

1484

ret_errno = errno;

1485

perror_plus("setuid");

1486

}

1487

errno = old_errno;

1488

return ret_errno;

1489

}

1490

1491

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

1895

__attribute__((nonnull))

1896

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

1492

1897

const float delay){

1493

struct dirent **direntries;

1494

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

1495

alphasort);

1898

struct dirent **direntries = NULL;

1899

if(hookdir_fd == -1){

1900

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1901

| O_CLOEXEC);

1902

if(hookdir_fd == -1){

1903

if(errno == ENOENT){

1904

if(debug){

1905

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

1906

" found\n", hookdir);

1907

}

1908

} else {

1909

perror_plus("open");

1910

}

1911

return;

1912

}

1913

}

1914

#ifdef __GLIBC__

1915

#if __GLIBC_PREREQ(2, 15)

1916

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

1917

runnable_hook, alphasort);

1918

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

1919

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

1920

alphasort);

1921

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

1922

#else /* not __GLIBC__ */

1923

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

1924

alphasort);

1925

#endif /* not __GLIBC__ */

1496

1926

if(numhooks == -1){

1497

if(errno == ENOENT){

1498

if(debug){

1499

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

1500

" found\n", hookdir);

1501

}

1502

} else {

1503

perror_plus("scandir");

1927

perror_plus("scandir");

1928

return;

1929

}

1930

struct dirent *direntry;

1931

int ret;

1932

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

1933

if(devnull == -1){

1934

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

1935

return;

1936

}

1937

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

1938

direntry = direntries[i];

1939

if(debug){

1940

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

1941

direntry->d_name);

1504

1942

}

1505

} else {

1506

struct dirent *direntry;

1507

int ret;

1508

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

1509

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

1510

direntry = direntries[i];

1511

char *fullname = NULL;

1512

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

1513

if(ret < 0){

1943

pid_t hook_pid = fork();

1944

if(hook_pid == 0){

1945

/* Child */

1946

/* Raise privileges */

1947

errno = raise_privileges_permanently();

1948

if(errno != 0){

1949

perror_plus("Failed to raise privileges");

1950

_exit(EX_NOPERM);

1951

}

1952

/* Set group */

1953

errno = 0;

1954

ret = setgid(0);

1955

if(ret == -1){

1956

perror_plus("setgid");

1957

_exit(EX_NOPERM);

1958

}

1959

/* Reset supplementary groups */

1960

errno = 0;

1961

ret = setgroups(0, NULL);

1962

if(ret == -1){

1963

perror_plus("setgroups");

1964

_exit(EX_NOPERM);

1965

}

1966

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

1967

if(ret == -1){

1968

perror_plus("setenv");

1969

_exit(EX_OSERR);

1970

}

1971

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

1972

if(ret == -1){

1973

perror_plus("setenv");

1974

_exit(EX_OSERR);

1975

}

1976

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

1977

if(ret == -1){

1978

perror_plus("setenv");

1979

_exit(EX_OSERR);

1980

}

1981

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

1982

if(ret == -1){

1983

perror_plus("setenv");

1984

_exit(EX_OSERR);

1985

}

1986

char *delaystring;

1987

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

1988

if(ret == -1){

1514

1989

perror_plus("asprintf");

1515

continue;

1516

}

1517

if(debug){

1518

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

1519

direntry->d_name);

1520

}

1521

pid_t hook_pid = fork();

1522

if(hook_pid == 0){

1523

/* Child */

1524

/* Raise privileges */

1525

raise_privileges_permanently();

1526

/* Set group */

1527

errno = 0;

1528

ret = setgid(0);

1529

if(ret == -1){

1530

perror_plus("setgid");

1531

}

1532

/* Reset supplementary groups */

1533

errno = 0;

1534

ret = setgroups(0, NULL);

1535

if(ret == -1){

1536

perror_plus("setgroups");

1537

}

1538

dup2(devnull, STDIN_FILENO);

1539

close(devnull);

1540

dup2(STDERR_FILENO, STDOUT_FILENO);

1541

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

1542

if(ret == -1){

1543

perror_plus("setenv");

1544

_exit(EX_OSERR);

1545

}

1546

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

1547

if(ret == -1){

1548

perror_plus("setenv");

1549

_exit(EX_OSERR);

1550

}

1551

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

1552

if(ret == -1){

1553

perror_plus("setenv");

1554

_exit(EX_OSERR);

1555

}

1556

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

1557

if(ret == -1){

1558

perror_plus("setenv");

1559

_exit(EX_OSERR);

1560

}

1561

char *delaystring;

1562

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

1563

if(ret == -1){

1564

perror_plus("asprintf");

1565

_exit(EX_OSERR);

1566

}

1567

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

1568

if(ret == -1){

1569

free(delaystring);

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1573

1994

free(delaystring);

1574

if(connect_to != NULL){

1575

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

1576

if(ret == -1){

1577

perror_plus("setenv");

1578

_exit(EX_OSERR);

1579

}

1580

}

1581

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

1582

perror_plus("execl");

1583

_exit(EXIT_FAILURE);

1584

}

1995

perror_plus("setenv");

1996

_exit(EX_OSERR);

1997

}

1998

free(delaystring);

1999

if(connect_to != NULL){

2000

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

2001

if(ret == -1){

2002

perror_plus("setenv");

2003

_exit(EX_OSERR);

2004

}

2005

}

2006

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

2007

direntry->d_name,

2008

O_RDONLY));

2009

if(hook_fd == -1){

2010

perror_plus("openat");

2011

_exit(EXIT_FAILURE);

2012

}

2013

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

2014

perror_plus("close");

2015

_exit(EXIT_FAILURE);

2016

}

2017

ret = dup2(devnull, STDIN_FILENO);

2018

if(ret == -1){

2019

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

2020

_exit(EX_OSERR);

2021

}

2022

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

2023

if(ret == -1){

2024

perror_plus("close");

2025

_exit(EX_OSERR);

2026

}

2027

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2028

if(ret == -1){

2029

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

2030

_exit(EX_OSERR);

2031

}

2032

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

2033

environ) == -1){

2034

perror_plus("fexecve");

2035

_exit(EXIT_FAILURE);

2036

}

2037

} else {

2038

if(hook_pid == -1){

2039

perror_plus("fork");

2040

free(direntry);

2041

continue;

2042

}

2043

int status;

2044

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

2045

perror_plus("waitpid");

2046

free(direntry);

2047

continue;

2048

}

2049

if(WIFEXITED(status)){

2050

if(WEXITSTATUS(status) != 0){

2051

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

2052

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

2053

WEXITSTATUS(status));

2054

free(direntry);

2055

continue;

2056

}

2057

} else if(WIFSIGNALED(status)){

2058

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

2059

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

2060

WTERMSIG(status));

2061

free(direntry);

2062

continue;

1585

2063

} else {

1586

int status;

1587

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

1588

perror_plus("waitpid");

1589

free(fullname);

1590

continue;

1591

}

1592

if(WIFEXITED(status)){

1593

if(WEXITSTATUS(status) != 0){

1594

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

1595

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

1596

WEXITSTATUS(status));

1597

free(fullname);

1598

continue;

1599

}

1600

} else if(WIFSIGNALED(status)){

1601

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

1602

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

1603

WTERMSIG(status));

1604

free(fullname);

1605

continue;

1606

} else {

1607

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

1608

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

1609

free(fullname);

1610

continue;

1611

}

1612

}

1613

free(fullname);

1614

if(debug){

1615

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

1616

direntry->d_name);

1617

}

1618

}

1619

close(devnull);

1620

}

1621

return true;

2064

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

2065

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

2066

free(direntry);

2067

continue;

2068

}

2069

}

2070

if(debug){

2071

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

2072

direntry->d_name);

2073

}

2074

free(direntry);

2075

}

2076

free(direntries);

2077

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

2078

perror_plus("close");

2079

} else {

2080

hookdir_fd = -1;

2081

}

2082

close(devnull);

1622

2083

}

1623

2084

2085

__attribute__((nonnull, warn_unused_result))

1624

2086

error_t bring_up_interface(const char *const interface,

1625

2087

const float delay){

1626

int sd = -1;

1627

2088

error_t old_errno = errno;

1628

error_t ret_errno = 0;

1629

int ret, ret_setflags;

2089

int ret;

1630

2090

struct ifreq network;

1631

2091

unsigned int if_index = if_nametoindex(interface);

1632

2092

if(if_index == 0){

1641

2101

}

1642

2102

1643

2103

if(not interface_is_up(interface)){

1644

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

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

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

1645

2106

ret_errno = errno;

1646

2107

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

1647

2108

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

2109

errno = old_errno;

1648

2110

return ret_errno;

1649

2111

}

1650

network.ifr_flags |= IFF_UP;

2112

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

1651

2113

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

2114

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

2115

if(sd == -1){

1654

2116

ret_errno = errno;

1655

2117

perror_plus("socket");

1656

2118

errno = old_errno;

1657

2119

return ret_errno;

1658

2120

}

1659

2121

1660

2122

if(quit_now){

1661

close(sd);

2123

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

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

1662

2127

errno = old_errno;

1663

2128

return EINTR;

1664

2129

}

1668

2133

interface);

1669

2134

}

1670

2135

1671

/* Raise priviliges */

1672

raise_privileges();

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

1673

2142

1674

2143

#ifdef __linux__

1675

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1676

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

1677

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

1678

bool restore_loglevel = true;

1679

if(ret_linux == -1){

1680

restore_loglevel = false;

1681

perror_plus("klogctl");

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

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

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

1682

2155

}

1683

2156

#endif /* __linux__ */

1684

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

1685

ret_errno = errno;

2157

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

2158

ioctl_errno = errno;

1686

2159

#ifdef __linux__

1687

2160

if(restore_loglevel){

1688

2161

ret_linux = klogctl(7, NULL, 0);

1692

2165

}

1693

2166

#endif /* __linux__ */

1694

2167

1695

/* Lower privileges */

1696

lower_privileges();

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

1697

2177

1698

2178

/* Close the socket */

1699

2179

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

1702

2182

}

1703

2183

1704

2184

if(ret_setflags == -1){

1705

errno = ret_errno;

2185

errno = ioctl_errno;

1706

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1707

2187

errno = old_errno;

1708

return ret_errno;

2188

return ioctl_errno;

1709

2189

}

1710

2190

} else if(debug){

1711

2191

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

1729

2209

return 0;

1730

2210

}

1731

2211

2212

__attribute__((nonnull, warn_unused_result))

1732

2213

error_t take_down_interface(const char *const interface){

1733

2214

error_t old_errno = errno;

1734

2215

struct ifreq network;

1739

2220

return ENXIO;

1740

2221

}

1741

2222

if(interface_is_up(interface)){

1742

error_t ret_errno = 0;

2223

error_t ret_errno = 0, ioctl_errno = 0;

1743

2224

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

1744

2225

ret_errno = errno;

1745

2226

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

1746

2227

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

2228

errno = old_errno;

1747

2229

return ret_errno;

1748

2230

}

1749

2231

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

1750

2232

1751

2233

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

1752

if(sd < 0){

2234

if(sd == -1){

1753

2235

ret_errno = errno;

1754

2236

perror_plus("socket");

1755

2237

errno = old_errno;

1761

2243

interface);

1762

2244

}

1763

2245

1764

/* Raise priviliges */

1765

raise_privileges();

2246

/* Raise privileges */

2247

ret_errno = raise_privileges();

2248

if(ret_errno != 0){

2249

errno = ret_errno;

2250

perror_plus("Failed to raise privileges");

2251

}

1766

2252

1767

2253

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

1768

ret_errno = errno;

2254

ioctl_errno = errno;

1769

2255

1770

/* Lower privileges */

1771

lower_privileges();

2256

/* If raise_privileges() succeeded above */

2257

if(ret_errno == 0){

2258

/* Lower privileges */

2259

ret_errno = lower_privileges();

2260

if(ret_errno != 0){

2261

errno = ret_errno;

2262

perror_plus("Failed to lower privileges");

2263

}

2264

}

1772

2265

1773

2266

/* Close the socket */

1774

2267

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

1777

2270

}

1778

2271

1779

2272

if(ret_setflags == -1){

1780

errno = ret_errno;

2273

errno = ioctl_errno;

1781

2274

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1782

2275

errno = old_errno;

1783

return ret_errno;

2276

return ioctl_errno;

1784

2277

}

1785

2278

} else if(debug){

1786

2279

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

1792

2285

}

1793

2286

1794

2287

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

1795

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

2288

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

1796

2289

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

1797

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

2290

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

1798

2291

.interfaces = NULL, .interfaces_size = 0 };

1799

2292

AvahiSServiceBrowser *sb = NULL;

1800

2293

error_t ret_errno;

1804

2297

int exitcode = EXIT_SUCCESS;

1805

2298

char *interfaces_to_take_down = NULL;

1806

2299

size_t interfaces_to_take_down_size = 0;

1807

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

1808

bool tempdir_created = false;

2300

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

2301

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

2302

char *tempdir = NULL;

1809

2303

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1810

2304

const char *seckey = PATHDIR "/" SECKEY;

1811

2305

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

1812

2307

char *interfaces_hooks = NULL;

1813

2308

1814

2309

bool gnutls_initialized = false;

1867

2362

.doc = "Bit length of the prime number used in the"

1868

2363

" Diffie-Hellman key exchange",

1869

2364

.group = 2 },

2365

{ .name = "dh-params", .key = 134,

2366

.arg = "FILE",

2367

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2368

" for the Diffie-Hellman key exchange",

2369

.group = 2 },

1870

2370

{ .name = "priority", .key = 130,

1871

2371

.arg = "STRING",

1872

2372

.doc = "GnuTLS priority string for the TLS handshake",

1927

2427

}

1928

2428

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

1929

2429

break;

2430

case 134: /* --dh-params */

2431

dh_params_file = arg;

2432

break;

1930

2433

case 130: /* --priority */

1931

2434

mc.priority = arg;

1932

2435

break;

1988

2491

goto end;

1989

2492

}

1990

2493

}

1991

2494

1992

2495

{

1993

2496

/* Work around Debian bug #633582:

1994

2497

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

1995

2498

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2499

/* Re-raise privileges */

2500

ret_errno = raise_privileges();

2501

if(ret_errno != 0){

2502

errno = ret_errno;

2503

perror_plus("Failed to raise privileges");

2504

} else {

1998

2505

struct stat st;

1999

2506

2000

2507

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

2017

2524

TEMP_FAILURE_RETRY(close(seckey_fd));

2018

2525

}

2019

2526

}

2020

2527

2021

2528

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

2022

2529

int pubkey_fd = open(pubkey, O_RDONLY);

2023

2530

if(pubkey_fd == -1){

2038

2545

TEMP_FAILURE_RETRY(close(pubkey_fd));

2039

2546

}

2040

2547

}

2041

2548

2549

if(strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2550

int dhparams_fd = open(dh_params_file, O_RDONLY);

2551

if(dhparams_fd == -1){

2552

perror_plus("open");

2553

} else {

2554

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2555

if(ret == -1){

2556

perror_plus("fstat");

2557

} else {

2558

if(S_ISREG(st.st_mode)

2559

and st.st_uid == 0 and st.st_gid == 0){

2560

ret = fchown(dhparams_fd, uid, gid);

2561

if(ret == -1){

2562

perror_plus("fchown");

2563

}

2564

}

2565

}

2566

TEMP_FAILURE_RETRY(close(dhparams_fd));

2567

}

2568

}

2569

2042

2570

/* Lower privileges */

2043

lower_privileges();

2571

ret_errno = lower_privileges();

2572

if(ret_errno != 0){

2573

errno = ret_errno;

2574

perror_plus("Failed to lower privileges");

2575

}

2044

2576

}

2045

2577

}

2046

2578

2072

2604

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

2073

2605

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

2074

2606

}

2075

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

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2607

run_network_hooks("start", interfaces_hooks != NULL ?

2608

interfaces_hooks : "", delay);

2079

2609

}

2080

2610

2081

2611

if(not debug){

2159

2689

2160

2690

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

2161

2691

if(mc.interfaces == NULL){

2162

struct dirent **direntries;

2692

struct dirent **direntries = NULL;

2163

2693

/* Look for any good interfaces */

2164

2694

ret = scandir(sys_class_net, &direntries, good_interface,

2165

2695

alphasort);

2171

2701

if(ret_errno != 0){

2172

2702

errno = ret_errno;

2173

2703

perror_plus("argz_add");

2704

free(direntries[i]);

2174

2705

continue;

2175

2706

}

2176

2707

if(debug){

2177

2708

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

2178

2709

direntries[i]->d_name);

2179

2710

}

2711

free(direntries[i]);

2180

2712

}

2181

2713

free(direntries);

2182

2714

} else {

2183

free(direntries);

2715

if(ret == 0){

2716

free(direntries);

2717

}

2184

2718

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

2185

2719

exitcode = EXIT_FAILURE;

2186

2720

goto end;

2209

2743

break;

2210

2744

}

2211

2745

bool interface_was_up = interface_is_up(interface);

2212

ret = bring_up_interface(interface, delay);

2746

errno = bring_up_interface(interface, delay);

2213

2747

if(not interface_was_up){

2214

if(ret != 0){

2215

errno = ret;

2748

if(errno != 0){

2216

2749

perror_plus("Failed to bring up interface");

2217

2750

} else {

2218

ret_errno = argz_add(&interfaces_to_take_down,

2219

&interfaces_to_take_down_size,

2220

interface);

2221

if(ret_errno != 0){

2222

errno = ret_errno;

2751

errno = argz_add(&interfaces_to_take_down,

2752

&interfaces_to_take_down_size,

2753

interface);

2754

if(errno != 0){

2223

2755

perror_plus("argz_add");

2224

2756

}

2225

2757

}

2243

2775

goto end;

2244

2776

}

2245

2777

2246

ret = init_gnutls_global(pubkey, seckey, &mc);

2778

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

2247

2779

if(ret == -1){

2248

2780

fprintf_plus(stderr, "init_gnutls_global failed\n");

2249

2781

exitcode = EX_UNAVAILABLE;

2256

2788

goto end;

2257

2789

}

2258

2790

2259

if(mkdtemp(tempdir) == NULL){

2791

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

2792

tempdir = mkdtemp(run_tempdir);

2793

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

2794

if(debug){

2795

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

2796

run_tempdir, old_tempdir);

2797

}

2798

tempdir = mkdtemp(old_tempdir);

2799

}

2800

if(tempdir == NULL){

2260

2801

perror_plus("mkdtemp");

2261

2802

goto end;

2262

2803

}

2263

tempdir_created = true;

2264

2804

2265

2805

if(quit_now){

2266

2806

goto end;

2341

2881

sleep((unsigned int)retry_interval);

2342

2882

}

2343

2883

2344

if (not quit_now){

2884

if(not quit_now){

2345

2885

exitcode = EXIT_SUCCESS;

2346

2886

}

2347

2887

2402

2942

if(debug){

2403

2943

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

2404

2944

}

2405

2945

2406

2946

ret = avahi_loop_with_timeout(simple_poll,

2407

2947

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

2408

2948

if(debug){

2444

2984

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

2445

2985

while(mc.current_server != NULL){

2446

2986

server *next = mc.current_server->next;

2987

#ifdef __GNUC__

2988

#pragma GCC diagnostic push

2989

#pragma GCC diagnostic ignored "-Wcast-qual"

2990

#endif

2991

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

2992

#ifdef __GNUC__

2993

#pragma GCC diagnostic pop

2994

#endif

2447

2995

free(mc.current_server);

2448

2996

mc.current_server = next;

2449

2997

}

2450

2998

}

2451

2999

2452

/* Re-raise priviliges */

3000

/* Re-raise privileges */

2453

3001

{

2454

raise_privileges();

2455

2456

/* Run network hooks */

2457

run_network_hooks("stop", interfaces_hooks != NULL ?

2458

interfaces_hooks : "", delay);

2459

2460

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

2461

{

2462

char *interface = NULL;

2463

while((interface=argz_next(interfaces_to_take_down,

2464

interfaces_to_take_down_size,

2465

interface))){

2466

ret_errno = take_down_interface(interface);

2467

if(ret_errno != 0){

2468

errno = ret_errno;

2469

perror_plus("Failed to take down interface");

2470

}

2471

}

2472

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

2473

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

2474

" down\n");

2475

}

2476

}

2477

2478

lower_privileges_permanently();

3002

ret_errno = raise_privileges();

3003

if(ret_errno != 0){

3004

errno = ret_errno;

3005

perror_plus("Failed to raise privileges");

3006

} else {

3007

3008

/* Run network hooks */

3009

run_network_hooks("stop", interfaces_hooks != NULL ?

3010

interfaces_hooks : "", delay);

3011

3012

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

3013

{

3014

char *interface = NULL;

3015

while((interface=argz_next(interfaces_to_take_down,

3016

interfaces_to_take_down_size,

3017

interface))){

3018

ret_errno = take_down_interface(interface);

3019

if(ret_errno != 0){

3020

errno = ret_errno;

3021

perror_plus("Failed to take down interface");

3022

}

3023

}

3024

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

3025

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

3026

" down\n");

3027

}

3028

}

3029

}

3030

3031

ret_errno = lower_privileges_permanently();

3032

if(ret_errno != 0){

3033

errno = ret_errno;

3034

perror_plus("Failed to lower privileges permanently");

3035

}

2479

3036

}

2480

3037

2481

3038

free(interfaces_to_take_down);

2482

3039

free(interfaces_hooks);

2483

3040

2484

3041

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

2485

if(tempdir_created){

3042

if(tempdir != NULL){

2486

3043

struct dirent **direntries = NULL;

2487

struct dirent *direntry = NULL;

2488

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

2489

alphasort);

2490

if (numentries > 0){

2491

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

2492

direntry = direntries[i];

2493

char *fullname = NULL;

2494

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

2495

direntry->d_name);

2496

if(ret < 0){

2497

perror_plus("asprintf");

2498

continue;

2499

}

2500

ret = remove(fullname);

2501

if(ret == -1){

2502

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

2503

strerror(errno));

2504

}

2505

free(fullname);

3044

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

3045

| O_NOFOLLOW

3046

| O_DIRECTORY

3047

| O_PATH));

3048

if(tempdir_fd == -1){

3049

perror_plus("open");

3050

} else {

3051

#ifdef __GLIBC__

3052

#if __GLIBC_PREREQ(2, 15)

3053

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

3054

notdotentries, alphasort);

3055

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

3056

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

3057

alphasort);

3058

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

3059

#else /* not __GLIBC__ */

3060

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

3061

alphasort);

3062

#endif /* not __GLIBC__ */

3063

if(numentries >= 0){

3064

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

3065

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

3066

if(ret == -1){

3067

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

3068

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

3069

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

3070

}

3071

free(direntries[i]);

3072

}

3073

3074

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

3075

free(direntries);

3076

if(numentries == -1){

3077

perror_plus("scandir");

3078

}

3079

ret = rmdir(tempdir);

3080

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

3081

perror_plus("rmdir");

3082

}

2506

3083

}

2507

}

2508

2509

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

2510

free(direntries);

2511

if (numentries == -1){

2512

perror_plus("scandir");

2513

}

2514

ret = rmdir(tempdir);

2515

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

2516

perror_plus("rmdir");

3084

TEMP_FAILURE_RETRY(close(tempdir_fd));

2517

3085

}

2518

3086

}

2519

3087