/mandos/release : revision 237.7.217

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 /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

41

42

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

43

stdout, ferror() */

43

stdout, ferror(), remove() */

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(),

47

strtof(), abort() */

48

#include <stdbool.h> /* bool, false, true */

49

#include <string.h> /* strcmp(), strlen(), strerror(),

50

asprintf(), strcpy() */

49

#include <string.h> /* memset(), strcmp(), strlen(),

50

strerror(), asprintf(), strcpy() */

51

#include <sys/ioctl.h> /* ioctl */

52

#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

53

sockaddr_in6, PF_INET6,

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

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

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(),

77

unlinkat() */

76

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

78

77

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

79

78

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

80

79

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

142

141

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

143

142

char *connect_to = NULL;

144

143

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

144

uid_t uid = 65534;

147

145

gid_t gid = 65534;

148

146

185

183

perror(print_text);

186

184

}

187

185

188

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

186

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

189

187

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

190

188

va_list ap;

191

189

va_start (ap, format);

200

198

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

201

199

* "buffer_length" is how much is already used.

202

200

*/

203

__attribute__((nonnull, warn_unused_result))

204

201

size_t incbuffer(char **buffer, size_t buffer_length,

205

202

size_t buffer_capacity){

206

203

if(buffer_length + BUFFER_SIZE > buffer_capacity){

219

216

}

220

217

221

218

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

222

__attribute__((nonnull, warn_unused_result))

223

219

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

224

220

int af, server **current_server){

225

221

int ret;

234

230

.af = af };

235

231

if(new_server->ip == NULL){

236

232

perror_plus("strdup");

237

free(new_server);

238

233

return false;

239

234

}

240

235

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

241

236

if(ret == -1){

242

237

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);

252

238

return false;

253

239

}

254

240

/* Special case of first server */

256

242

new_server->next = new_server;

257

243

new_server->prev = new_server;

258

244

*current_server = new_server;

245

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

259

246

} else {

260

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

261

247

new_server->next = *current_server;

262

248

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

263

249

new_server->prev->next = new_server;

269

255

/*

270

256

* Initialize GPGME.

271

257

*/

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){

258

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

259

const char *tempdir, mandos_context *mc){

277

260

gpgme_error_t rc;

278

261

gpgme_engine_info_t engine_info;

279

262

280

263

/*

281

264

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

282

265

*/

283

bool import_key(const char * const filename){

266

bool import_key(const char *filename){

284

267

int ret;

285

268

int fd;

286

269

gpgme_data_t pgp_data;

305

288

return false;

306

289

}

307

290

308

ret = close(fd);

291

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

309

292

if(ret == -1){

310

293

perror_plus("close");

311

294

}

367

350

* Decrypt OpenPGP data.

368

351

* Returns -1 on error

369

352

*/

370

__attribute__((nonnull, warn_unused_result))

371

353

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

354

size_t crypto_size,

373

355

char **plaintext,

493

475

return plaintext_length;

494

476

}

495

477

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){

478

static const char * safer_gnutls_strerror(int value){

505

479

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

507

483

}

508

484

509

485

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

486

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

512

487

const char* string){

513

488

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

514

489

}

515

490

516

__attribute__((nonnull, warn_unused_result))

517

491

static int init_gnutls_global(const char *pubkeyfilename,

518

492

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

493

mandos_context *mc){

521

494

int ret;

522

unsigned int uret;

523

495

524

496

if(debug){

525

497

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

576

548

safer_gnutls_strerror(ret));

577

549

goto globalfail;

578

550

}

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

}

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

751

558

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

752

559

753

560

return 0;

760

567

return -1;

761

568

}

762

569

763

__attribute__((nonnull, warn_unused_result))

764

570

static int init_gnutls_session(gnutls_session_t *session,

765

571

mandos_context *mc){

766

572

int ret;

813

619

/* ignore client certificate if any. */

814

620

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

621

622

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

623

816

624

return 0;

817

625

}

818

626

820

628

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

821

629

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

822

630

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 = 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

close(helperdir_fd);

958

_exit(EX_UNAVAILABLE);

959

}

960

close(helperdir_fd);

961

#ifdef __GNUC__

962

#pragma GCC diagnostic push

963

#pragma GCC diagnostic ignored "-Wcast-qual"

964

#endif

965

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

966

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

967

interface, debug ? debug_flag : NULL, NULL },

968

environ) == -1){

969

#ifdef __GNUC__

970

#pragma GCC diagnostic pop

971

#endif

972

perror_plus("fexecve");

973

_exit(EXIT_FAILURE);

974

}

975

}

976

if(pid == -1){

977

perror_plus("fork");

978

return false;

979

}

980

int status;

981

pid_t pret = -1;

982

errno = 0;

983

do {

984

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

985

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

986

int errno_raising = 0;

987

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

988

errno_raising = errno;

989

perror_plus("Failed to raise privileges in order to"

990

" kill helper program");

991

}

992

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

993

perror_plus("kill");

994

}

995

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

996

perror_plus("Failed to lower privileges after killing"

997

" helper program");

998

}

999

return false;

1000

}

1001

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

1002

if(pret == -1){

1003

perror_plus("waitpid");

1004

return false;

1005

}

1006

if(WIFEXITED(status)){

1007

if(WEXITSTATUS(status) != 0){

1008

fprintf_plus(stderr, "Error: iprouteadddel exited"

1009

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

1010

return false;

1011

}

1012

return true;

1013

}

1014

if(WIFSIGNALED(status)){

1015

fprintf_plus(stderr, "Error: iprouteadddel died by"

1016

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

1017

return false;

1018

}

1019

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

1020

return false;

1021

}

1022

1023

__attribute__((nonnull, warn_unused_result))

1024

static bool add_local_route(const char *address,

1025

AvahiIfIndex if_index){

1026

if(debug){

1027

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

1028

}

1029

return add_delete_local_route(true, address, if_index);

1030

}

1031

1032

__attribute__((nonnull, warn_unused_result))

1033

static bool delete_local_route(const char *address,

1034

AvahiIfIndex if_index){

1035

if(debug){

1036

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

1037

}

1038

return add_delete_local_route(false, address, if_index);

1039

}

1040

1041

631

/* Called when a Mandos server is found */

1042

__attribute__((nonnull, warn_unused_result))

1043

632

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

1044

633

AvahiIfIndex if_index,

1045

634

int af, mandos_context *mc){

1054

643

int retval = -1;

1055

644

gnutls_session_t session;

1056

645

int pf; /* Protocol family */

1057

bool route_added = false;

1058

646

1059

647

errno = 0;

1060

648

1118

706

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

1119

707

}

1120

708

1121

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

709

tcp_sd = socket(pf, SOCK_STREAM, 0);

1122

710

if(tcp_sd < 0){

1123

711

int e = errno;

1124

712

perror_plus("socket");

1131

719

goto mandos_end;

1132

720

}

1133

721

722

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

1134

723

if(af == AF_INET6){

1135

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1136

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1137

ret = inet_pton(af, ip, &to6->sin6_addr);

724

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

725

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

1138

726

} else { /* IPv4 */

1139

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1140

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1141

ret = inet_pton(af, ip, &to4->sin_addr);

727

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

728

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

1142

729

}

1143

730

if(ret < 0 ){

1144

731

int e = errno;

1153

740

goto mandos_end;

1154

741

}

1155

742

if(af == AF_INET6){

1156

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

743

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

1157

744

if(IN6_IS_ADDR_LINKLOCAL

1158

745

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

1159

746

if(if_index == AVAHI_IF_UNSPEC){

1214

801

goto mandos_end;

1215

802

}

1216

803

1217

while(true){

1218

if(af == AF_INET6){

1219

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

1220

sizeof(struct sockaddr_in6));

1221

} else {

1222

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

1223

sizeof(struct sockaddr_in));

1224

}

1225

if(ret < 0){

1226

if(errno == ENETUNREACH

1227

and if_index != AVAHI_IF_UNSPEC

1228

and connect_to == NULL

1229

and not route_added and

1230

((af == AF_INET6 and not

1231

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1232

&to)->sin6_addr)))

1233

or (af == AF_INET and

1234

/* Not a a IPv4LL address */

1235

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

1236

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

1237

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

1238

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

1239

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

1240

connect to a Mandos server announced by Avahi on a server

1241

host with a global address. Work around this by retrying

1242

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

1243

1244

Avahi bug reference:

1245

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

1246

https://bugs.debian.org/587961

1247

*/

1248

if(debug){

1249

fprintf_plus(stderr, "Mandos server unreachable, trying"

1250

" direct route\n");

1251

}

1252

int e = errno;

1253

route_added = add_local_route(ip, if_index);

1254

if(route_added){

1255

continue;

1256

}

1257

errno = e;

1258

}

1259

if(errno != ECONNREFUSED or debug){

1260

int e = errno;

1261

perror_plus("connect");

1262

errno = e;

1263

}

1264

goto mandos_end;

1265

}

1266

1267

if(quit_now){

1268

errno = EINTR;

1269

goto mandos_end;

1270

}

1271

break;

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;

1272

823

}

1273

824

1274

825

const char *out = mandos_protocol_version;

1457

1008

1458

1009

mandos_end:

1459

1010

{

1460

if(route_added){

1461

if(not delete_local_route(ip, if_index)){

1462

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

1463

" interface %d", ip, if_index);

1464

}

1465

}

1466

1011

int e = errno;

1467

1012

free(decrypted_buffer);

1468

1013

free(buffer);

1469

1014

if(tcp_sd >= 0){

1470

ret = close(tcp_sd);

1015

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

1471

1016

}

1472

1017

if(ret == -1){

1473

1018

if(e == 0){

1485

1030

return retval;

1486

1031

}

1487

1032

1488

__attribute__((nonnull))

1489

1033

static void resolve_callback(AvahiSServiceResolver *r,

1490

1034

AvahiIfIndex interface,

1491

1035

AvahiProtocol proto,

1499

1043

AVAHI_GCC_UNUSED AvahiStringList *txt,

1500

1044

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1501

1045

flags,

1502

void *mc){

1046

void* mc){

1503

1047

if(r == NULL){

1504

1048

return;

1505

1049

}

1508

1052

timed out */

1509

1053

1510

1054

if(quit_now){

1511

avahi_s_service_resolver_free(r);

1512

1055

return;

1513

1056

}

1514

1057

1559

1102

const char *domain,

1560

1103

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1561

1104

flags,

1562

void *mc){

1105

void* mc){

1563

1106

if(b == NULL){

1564

1107

return;

1565

1108

}

1625

1168

errno = old_errno;

1626

1169

}

1627

1170

1628

__attribute__((nonnull, warn_unused_result))

1629

1171

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

1630

1172

int ret;

1631

1173

error_t ret_errno;

1650

1192

return true;

1651

1193

}

1652

1194

1653

__attribute__((nonnull, warn_unused_result))

1654

1195

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

1655

1196

1656

1197

/* Reject the loopback device */

1698

1239

* corresponds to an acceptable network device.

1699

1240

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

1700

1241

*/

1701

__attribute__((nonnull, warn_unused_result))

1702

1242

int good_interface(const struct dirent *if_entry){

1703

1243

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

1704

1244

return 0;

1722

1262

/*

1723

1263

* This function determines if a network interface is up.

1724

1264

*/

1725

__attribute__((nonnull, warn_unused_result))

1726

1265

bool interface_is_up(const char *interface){

1727

1266

struct ifreq ifr;

1728

1267

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

1739

1278

/*

1740

1279

* This function determines if a network interface is running

1741

1280

*/

1742

__attribute__((nonnull, warn_unused_result))

1743

1281

bool interface_is_running(const char *interface){

1744

1282

struct ifreq ifr;

1745

1283

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

1753

1291

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

1754

1292

}

1755

1293

1756

__attribute__((nonnull, pure, warn_unused_result))

1757

1294

int notdotentries(const struct dirent *direntry){

1758

1295

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

1759

1296

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

1766

1303

}

1767

1304

1768

1305

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

1769

__attribute__((nonnull, warn_unused_result))

1770

1306

int runnable_hook(const struct dirent *direntry){

1771

1307

int ret;

1772

1308

size_t sret;

1780

1316

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

1781

1317

"abcdefghijklmnopqrstuvwxyz"

1782

1318

"0123456789"

1783

"_.-");

1319

"_-");

1784

1320

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

1785

1321

/* Contains non-allowed characters */

1786

1322

if(debug){

1790

1326

return 0;

1791

1327

}

1792

1328

1793

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

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);

1794

1337

if(ret == -1){

1795

1338

if(debug){

1796

1339

perror_plus("Could not stat hook");

1820

1363

return 1;

1821

1364

}

1822

1365

1823

__attribute__((nonnull, warn_unused_result))

1824

1366

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1825

1367

mandos_context *mc){

1826

1368

int ret;

1830

1372

1831

1373

while(true){

1832

1374

if(mc->current_server == NULL){

1833

if(debug){

1375

if (debug){

1834

1376

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

1835

1377

" No timeout!\n");

1836

1378

}

1837

1379

ret = avahi_simple_poll_iterate(s, -1);

1838

1380

} else {

1839

if(debug){

1381

if (debug){

1840

1382

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

1841

1383

" it, or wait\n");

1842

1384

}

1859

1401

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

1860

1402

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

1861

1403

1862

if(debug){

1404

if (debug){

1863

1405

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

1864

1406

block_time);

1865

1407

}

1887

1429

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

1888

1430

}

1889

1431

if(ret != 0){

1890

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

1432

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

1891

1433

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

1892

1434

}

1893

1435

}

1894

1436

}

1895

1437

}

1896

1438

1897

__attribute__((nonnull))

1898

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

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,

1899

1492

const float delay){

1900

struct dirent **direntries = NULL;

1901

if(hookdir_fd == -1){

1902

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1903

| O_CLOEXEC);

1904

if(hookdir_fd == -1){

1905

if(errno == ENOENT){

1906

if(debug){

1907

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

1908

" found\n", hookdir);

1909

}

1910

} else {

1911

perror_plus("open");

1912

}

1913

return;

1914

}

1915

}

1916

#ifdef __GLIBC__

1917

#if __GLIBC_PREREQ(2, 15)

1918

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

1919

runnable_hook, alphasort);

1920

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

1921

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

1922

alphasort);

1923

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

1924

#else /* not __GLIBC__ */

1925

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

1926

alphasort);

1927

#endif /* not __GLIBC__ */

1493

struct dirent **direntries;

1494

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

1495

alphasort);

1928

1496

if(numhooks == -1){

1929

perror_plus("scandir");

1930

return;

1931

}

1932

struct dirent *direntry;

1933

int ret;

1934

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

1935

if(devnull == -1){

1936

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

1937

return;

1938

}

1939

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

1940

direntry = direntries[i];

1941

if(debug){

1942

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

1943

direntry->d_name);

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");

1944

1504

}

1945

pid_t hook_pid = fork();

1946

if(hook_pid == 0){

1947

/* Child */

1948

/* Raise privileges */

1949

errno = raise_privileges_permanently();

1950

if(errno != 0){

1951

perror_plus("Failed to raise privileges");

1952

_exit(EX_NOPERM);

1953

}

1954

/* Set group */

1955

errno = 0;

1956

ret = setgid(0);

1957

if(ret == -1){

1958

perror_plus("setgid");

1959

_exit(EX_NOPERM);

1960

}

1961

/* Reset supplementary groups */

1962

errno = 0;

1963

ret = setgroups(0, NULL);

1964

if(ret == -1){

1965

perror_plus("setgroups");

1966

_exit(EX_NOPERM);

1967

}

1968

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

1969

if(ret == -1){

1970

perror_plus("setenv");

1971

_exit(EX_OSERR);

1972

}

1973

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

1974

if(ret == -1){

1975

perror_plus("setenv");

1976

_exit(EX_OSERR);

1977

}

1978

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

1979

if(ret == -1){

1980

perror_plus("setenv");

1981

_exit(EX_OSERR);

1982

}

1983

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

1984

if(ret == -1){

1985

perror_plus("setenv");

1986

_exit(EX_OSERR);

1987

}

1988

char *delaystring;

1989

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

1990

if(ret == -1){

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){

1991

1514

perror_plus("asprintf");

1992

_exit(EX_OSERR);

1993

}

1994

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

1995

if(ret == -1){

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

}

1996

1573

free(delaystring);

1997

perror_plus("setenv");

1998

_exit(EX_OSERR);

1999

}

2000

free(delaystring);

2001

if(connect_to != NULL){

2002

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

2003

if(ret == -1){

2004

perror_plus("setenv");

2005

_exit(EX_OSERR);

2006

}

2007

}

2008

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

2009

direntry->d_name,

2010

O_RDONLY));

2011

if(hook_fd == -1){

2012

perror_plus("openat");

2013

_exit(EXIT_FAILURE);

2014

}

2015

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

2016

perror_plus("close");

2017

_exit(EXIT_FAILURE);

2018

}

2019

ret = dup2(devnull, STDIN_FILENO);

2020

if(ret == -1){

2021

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

2022

_exit(EX_OSERR);

2023

}

2024

ret = close(devnull);

2025

if(ret == -1){

2026

perror_plus("close");

2027

_exit(EX_OSERR);

2028

}

2029

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2030

if(ret == -1){

2031

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

2032

_exit(EX_OSERR);

2033

}

2034

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

2035

environ) == -1){

2036

perror_plus("fexecve");

2037

_exit(EXIT_FAILURE);

2038

}

2039

} else {

2040

if(hook_pid == -1){

2041

perror_plus("fork");

2042

free(direntry);

2043

continue;

2044

}

2045

int status;

2046

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

2047

perror_plus("waitpid");

2048

free(direntry);

2049

continue;

2050

}

2051

if(WIFEXITED(status)){

2052

if(WEXITSTATUS(status) != 0){

2053

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

2054

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

2055

WEXITSTATUS(status));

2056

free(direntry);

2057

continue;

2058

}

2059

} else if(WIFSIGNALED(status)){

2060

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

2061

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

2062

WTERMSIG(status));

2063

free(direntry);

2064

continue;

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

}

2065

1585

} else {

2066

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

2067

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

2068

free(direntry);

2069

continue;

2070

}

2071

}

2072

if(debug){

2073

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

2074

direntry->d_name);

2075

}

2076

free(direntry);

2077

}

2078

free(direntries);

2079

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

2080

perror_plus("close");

2081

} else {

2082

hookdir_fd = -1;

2083

}

2084

close(devnull);

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;

2085

1622

}

2086

1623

2087

__attribute__((nonnull, warn_unused_result))

2088

1624

error_t bring_up_interface(const char *const interface,

2089

1625

const float delay){

1626

int sd = -1;

2090

1627

error_t old_errno = errno;

2091

int ret;

1628

error_t ret_errno = 0;

1629

int ret, ret_setflags;

2092

1630

struct ifreq network;

2093

1631

unsigned int if_index = if_nametoindex(interface);

2094

1632

if(if_index == 0){

2103

1641

}

2104

1642

2105

1643

if(not interface_is_up(interface)){

2106

error_t ret_errno = 0, ioctl_errno = 0;

2107

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

1644

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

2108

1645

ret_errno = errno;

2109

1646

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

2110

1647

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

2111

errno = old_errno;

2112

1648

return ret_errno;

2113

1649

}

2114

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

1650

network.ifr_flags |= IFF_UP;

2115

1651

2116

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

2117

if(sd == -1){

1652

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1653

if(sd < 0){

2118

1654

ret_errno = errno;

2119

1655

perror_plus("socket");

2120

1656

errno = old_errno;

2121

1657

return ret_errno;

2122

1658

}

2123

1659

2124

1660

if(quit_now){

2125

ret = close(sd);

2126

if(ret == -1){

2127

perror_plus("close");

2128

}

1661

close(sd);

2129

1662

errno = old_errno;

2130

1663

return EINTR;

2131

1664

}

2135

1668

interface);

2136

1669

}

2137

1670

2138

/* Raise privileges */

2139

ret_errno = raise_privileges();

2140

if(ret_errno != 0){

2141

errno = ret_errno;

2142

perror_plus("Failed to raise privileges");

2143

}

1671

/* Raise priviliges */

1672

raise_privileges();

2144

1673

2145

1674

#ifdef __linux__

2146

int ret_linux;

2147

bool restore_loglevel = false;

2148

if(ret_errno == 0){

2149

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2150

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

2151

ret_linux = klogctl(8, NULL, 5);

2152

if(ret_linux == -1){

2153

perror_plus("klogctl");

2154

} else {

2155

restore_loglevel = true;

2156

}

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");

2157

1682

}

2158

1683

#endif /* __linux__ */

2159

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

2160

ioctl_errno = errno;

1684

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

1685

ret_errno = errno;

2161

1686

#ifdef __linux__

2162

1687

if(restore_loglevel){

2163

1688

ret_linux = klogctl(7, NULL, 0);

2167

1692

}

2168

1693

#endif /* __linux__ */

2169

1694

2170

/* If raise_privileges() succeeded above */

2171

if(ret_errno == 0){

2172

/* Lower privileges */

2173

ret_errno = lower_privileges();

2174

if(ret_errno != 0){

2175

errno = ret_errno;

2176

perror_plus("Failed to lower privileges");

2177

}

2178

}

1695

/* Lower privileges */

1696

lower_privileges();

2179

1697

2180

1698

/* Close the socket */

2181

ret = close(sd);

1699

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

2182

1700

if(ret == -1){

2183

1701

perror_plus("close");

2184

1702

}

2185

1703

2186

1704

if(ret_setflags == -1){

2187

errno = ioctl_errno;

1705

errno = ret_errno;

2188

1706

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2189

1707

errno = old_errno;

2190

return ioctl_errno;

1708

return ret_errno;

2191

1709

}

2192

1710

} else if(debug){

2193

1711

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

2211

1729

return 0;

2212

1730

}

2213

1731

2214

__attribute__((nonnull, warn_unused_result))

2215

1732

error_t take_down_interface(const char *const interface){

2216

1733

error_t old_errno = errno;

2217

1734

struct ifreq network;

2222

1739

return ENXIO;

2223

1740

}

2224

1741

if(interface_is_up(interface)){

2225

error_t ret_errno = 0, ioctl_errno = 0;

1742

error_t ret_errno = 0;

2226

1743

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

2227

1744

ret_errno = errno;

2228

1745

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

2229

1746

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

2230

errno = old_errno;

2231

1747

return ret_errno;

2232

1748

}

2233

1749

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

2234

1750

2235

1751

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

2236

if(sd == -1){

1752

if(sd < 0){

2237

1753

ret_errno = errno;

2238

1754

perror_plus("socket");

2239

1755

errno = old_errno;

2245

1761

interface);

2246

1762

}

2247

1763

2248

/* Raise privileges */

2249

ret_errno = raise_privileges();

2250

if(ret_errno != 0){

2251

errno = ret_errno;

2252

perror_plus("Failed to raise privileges");

2253

}

1764

/* Raise priviliges */

1765

raise_privileges();

2254

1766

2255

1767

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

2256

ioctl_errno = errno;

1768

ret_errno = errno;

2257

1769

2258

/* If raise_privileges() succeeded above */

2259

if(ret_errno == 0){

2260

/* Lower privileges */

2261

ret_errno = lower_privileges();

2262

if(ret_errno != 0){

2263

errno = ret_errno;

2264

perror_plus("Failed to lower privileges");

2265

}

2266

}

1770

/* Lower privileges */

1771

lower_privileges();

2267

1772

2268

1773

/* Close the socket */

2269

int ret = close(sd);

1774

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

2270

1775

if(ret == -1){

2271

1776

perror_plus("close");

2272

1777

}

2273

1778

2274

1779

if(ret_setflags == -1){

2275

errno = ioctl_errno;

1780

errno = ret_errno;

2276

1781

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2277

1782

errno = old_errno;

2278

return ioctl_errno;

1783

return ret_errno;

2279

1784

}

2280

1785

} else if(debug){

2281

1786

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

2287

1792

}

2288

1793

2289

1794

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

2290

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

2291

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

2292

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2293

.current_server = NULL, .interfaces = NULL,

2294

.interfaces_size = 0 };

1795

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

1796

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

1797

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

1798

.interfaces = NULL, .interfaces_size = 0 };

2295

1799

AvahiSServiceBrowser *sb = NULL;

2296

1800

error_t ret_errno;

2297

1801

int ret;

2300

1804

int exitcode = EXIT_SUCCESS;

2301

1805

char *interfaces_to_take_down = NULL;

2302

1806

size_t interfaces_to_take_down_size = 0;

2303

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

2304

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

2305

char *tempdir = NULL;

1807

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

1808

bool tempdir_created = false;

2306

1809

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2307

1810

const char *seckey = PATHDIR "/" SECKEY;

2308

1811

const char *pubkey = PATHDIR "/" PUBKEY;

2309

const char *dh_params_file = NULL;

2310

1812

char *interfaces_hooks = NULL;

2311

1813

2312

1814

bool gnutls_initialized = false;

2365

1867

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

2366

1868

" Diffie-Hellman key exchange",

2367

1869

.group = 2 },

2368

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

2369

.arg = "FILE",

2370

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

2371

" for the Diffie-Hellman key exchange",

2372

.group = 2 },

2373

1870

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

2374

1871

.arg = "STRING",

2375

1872

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

2430

1927

}

2431

1928

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

2432

1929

break;

2433

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

2434

dh_params_file = arg;

2435

break;

2436

1930

case 130: /* --priority */

2437

1931

mc.priority = arg;

2438

1932

break;

2494

1988

goto end;

2495

1989

}

2496

1990

}

2497

1991

2498

1992

{

2499

1993

/* Work around Debian bug #633582:

2500

1994

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

2501

1995

2502

/* Re-raise privileges */

2503

ret_errno = raise_privileges();

2504

if(ret_errno != 0){

2505

errno = ret_errno;

2506

perror_plus("Failed to raise privileges");

2507

} else {

1996

/* Re-raise priviliges */

1997

if(raise_privileges() == 0){

2508

1998

struct stat st;

2509

1999

2510

2000

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

2524

2014

}

2525

2015

}

2526

2016

}

2527

close(seckey_fd);

2017

TEMP_FAILURE_RETRY(close(seckey_fd));

2528

2018

}

2529

2019

}

2530

2020

2531

2021

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

2532

2022

int pubkey_fd = open(pubkey, O_RDONLY);

2533

2023

if(pubkey_fd == -1){

2545

2035

}

2546

2036

}

2547

2037

}

2548

close(pubkey_fd);

2549

}

2550

}

2551

2552

if(dh_params_file != NULL

2553

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

2554

int dhparams_fd = open(dh_params_file, O_RDONLY);

2555

if(dhparams_fd == -1){

2556

perror_plus("open");

2557

} else {

2558

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

2559

if(ret == -1){

2560

perror_plus("fstat");

2561

} else {

2562

if(S_ISREG(st.st_mode)

2563

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

2564

ret = fchown(dhparams_fd, uid, gid);

2565

if(ret == -1){

2566

perror_plus("fchown");

2567

}

2568

}

2569

}

2570

close(dhparams_fd);

2571

}

2572

}

2573

2038

TEMP_FAILURE_RETRY(close(pubkey_fd));

2039

}

2040

}

2041

2574

2042

/* Lower privileges */

2575

ret_errno = lower_privileges();

2576

if(ret_errno != 0){

2577

errno = ret_errno;

2578

perror_plus("Failed to lower privileges");

2579

}

2043

lower_privileges();

2580

2044

}

2581

2045

}

2582

2046

2608

2072

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

2609

2073

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

2610

2074

}

2611

run_network_hooks("start", interfaces_hooks != NULL ?

2612

interfaces_hooks : "", delay);

2075

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

2076

interfaces_hooks : "", delay)){

2077

goto end;

2078

}

2613

2079

}

2614

2080

2615

2081

if(not debug){

2693

2159

2694

2160

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

2695

2161

if(mc.interfaces == NULL){

2696

struct dirent **direntries = NULL;

2162

struct dirent **direntries;

2697

2163

/* Look for any good interfaces */

2698

2164

ret = scandir(sys_class_net, &direntries, good_interface,

2699

2165

alphasort);

2705

2171

if(ret_errno != 0){

2706

2172

errno = ret_errno;

2707

2173

perror_plus("argz_add");

2708

free(direntries[i]);

2709

2174

continue;

2710

2175

}

2711

2176

if(debug){

2712

2177

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

2713

2178

direntries[i]->d_name);

2714

2179

}

2715

free(direntries[i]);

2716

2180

}

2717

2181

free(direntries);

2718

2182

} else {

2719

if(ret == 0){

2720

free(direntries);

2721

}

2183

free(direntries);

2722

2184

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

2723

2185

exitcode = EXIT_FAILURE;

2724

2186

goto end;

2747

2209

break;

2748

2210

}

2749

2211

bool interface_was_up = interface_is_up(interface);

2750

errno = bring_up_interface(interface, delay);

2212

ret = bring_up_interface(interface, delay);

2751

2213

if(not interface_was_up){

2752

if(errno != 0){

2753

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2754

" %s\n", interface, strerror(errno));

2214

if(ret != 0){

2215

errno = ret;

2216

perror_plus("Failed to bring up interface");

2755

2217

} else {

2756

errno = argz_add(&interfaces_to_take_down,

2757

&interfaces_to_take_down_size,

2758

interface);

2759

if(errno != 0){

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;

2760

2223

perror_plus("argz_add");

2761

2224

}

2762

2225

}

2780

2243

goto end;

2781

2244

}

2782

2245

2783

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

2246

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

2784

2247

if(ret == -1){

2785

2248

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

2786

2249

exitcode = EX_UNAVAILABLE;

2793

2256

goto end;

2794

2257

}

2795

2258

2796

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

2797

tempdir = mkdtemp(run_tempdir);

2798

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

2799

if(debug){

2800

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

2801

run_tempdir, old_tempdir);

2802

}

2803

tempdir = mkdtemp(old_tempdir);

2804

}

2805

if(tempdir == NULL){

2259

if(mkdtemp(tempdir) == NULL){

2806

2260

perror_plus("mkdtemp");

2807

2261

goto end;

2808

2262

}

2263

tempdir_created = true;

2809

2264

2810

2265

if(quit_now){

2811

2266

goto end;

2886

2341

sleep((unsigned int)retry_interval);

2887

2342

}

2888

2343

2889

if(not quit_now){

2344

if (not quit_now){

2890

2345

exitcode = EXIT_SUCCESS;

2891

2346

}

2892

2347

2947

2402

if(debug){

2948

2403

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

2949

2404

}

2950

2405

2951

2406

ret = avahi_loop_with_timeout(simple_poll,

2952

2407

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

2953

2408

if(debug){

2989

2444

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

2990

2445

while(mc.current_server != NULL){

2991

2446

server *next = mc.current_server->next;

2992

#ifdef __GNUC__

2993

#pragma GCC diagnostic push

2994

#pragma GCC diagnostic ignored "-Wcast-qual"

2995

#endif

2996

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

2997

#ifdef __GNUC__

2998

#pragma GCC diagnostic pop

2999

#endif

3000

2447

free(mc.current_server);

3001

2448

mc.current_server = next;

3002

2449

}

3003

2450

}

3004

2451

3005

/* Re-raise privileges */

2452

/* Re-raise priviliges */

3006

2453

{

3007

ret_errno = raise_privileges();

3008

if(ret_errno != 0){

3009

errno = ret_errno;

3010

perror_plus("Failed to raise privileges");

3011

} else {

3012

3013

/* Run network hooks */

3014

run_network_hooks("stop", interfaces_hooks != NULL ?

3015

interfaces_hooks : "", delay);

3016

3017

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

3018

{

3019

char *interface = NULL;

3020

while((interface=argz_next(interfaces_to_take_down,

3021

interfaces_to_take_down_size,

3022

interface))){

3023

ret_errno = take_down_interface(interface);

3024

if(ret_errno != 0){

3025

errno = ret_errno;

3026

perror_plus("Failed to take down interface");

3027

}

3028

}

3029

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

3030

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

3031

" down\n");

3032

}

3033

}

3034

}

3035

3036

ret_errno = lower_privileges_permanently();

3037

if(ret_errno != 0){

3038

errno = ret_errno;

3039

perror_plus("Failed to lower privileges permanently");

3040

}

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();

3041

2479

}

3042

2480

3043

2481

free(interfaces_to_take_down);

3044

2482

free(interfaces_hooks);

3045

2483

3046

2484

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

3047

if(tempdir != NULL){

2485

if(tempdir_created){

3048

2486

struct dirent **direntries = NULL;

3049

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

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(tempdir_fd == -1){

3054

perror_plus("open");

3055

} else {

3056

#ifdef __GLIBC__

3057

#if __GLIBC_PREREQ(2, 15)

3058

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

3059

notdotentries, alphasort);

3060

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

3061

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

3062

alphasort);

3063

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

3064

#else /* not __GLIBC__ */

3065

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

3066

alphasort);

3067

#endif /* not __GLIBC__ */

3068

if(numentries >= 0){

3069

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

3070

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

3071

if(ret == -1){

3072

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

3073

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

3074

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

3075

}

3076

free(direntries[i]);

3077

}

3078

3079

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

3080

free(direntries);

3081

if(numentries == -1){

3082

perror_plus("scandir");

3083

}

3084

ret = rmdir(tempdir);

3085

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

3086

perror_plus("rmdir");

3087

}

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);

3088

2506

}

3089

close(tempdir_fd);

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");

3090

2517

}

3091

2518

}

3092

2519