/mandos/trunk : revision 617

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(),

55

opendir(), DIR */

56

#include <sys/stat.h> /* open(), S_ISREG */

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

58

inet_pton(), connect() */

59

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

61

60

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

62

61

*/

63

62

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

73

72

*/

74

73

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

75

74

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

76

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

77

unlinkat() */

78

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

75

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

76

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

79

77

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

80

78

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

81

79

argp_state, struct argp,

93

91

argz_delete(), argz_append(),

94

92

argz_stringify(), argz_add(),

95

93

argz_count() */

96

#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

97

EAI_SYSTEM, gai_strerror() */

98

94

99

95

#ifdef __linux__

100

96

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

142

138

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

143

139

char *connect_to = NULL;

144

140

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

141

uid_t uid = 65534;

147

142

gid_t gid = 65534;

148

143

185

180

perror(print_text);

186

181

}

187

182

188

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

183

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

189

184

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

190

185

va_list ap;

191

186

va_start (ap, format);

192

187

193

188

TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",

194

189

program_invocation_short_name));

195

return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

190

return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

196

191

}

197

192

198

193

/*

200

195

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

201

196

* "buffer_length" is how much is already used.

202

197

*/

203

__attribute__((nonnull, warn_unused_result))

204

198

size_t incbuffer(char **buffer, size_t buffer_length,

205

199

size_t buffer_capacity){

206

200

if(buffer_length + BUFFER_SIZE > buffer_capacity){

207

char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

201

*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

202

if(buffer == NULL){

213

203

return 0;

214

204

}

215

*buffer = new_buf;

216

205

buffer_capacity += BUFFER_SIZE;

217

206

}

218

207

return buffer_capacity;

219

208

}

220

209

221

210

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

222

__attribute__((nonnull, warn_unused_result))

223

211

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

224

212

int af, server **current_server){

225

213

int ret;

234

222

.af = af };

235

223

if(new_server->ip == NULL){

236

224

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

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);

252

225

return false;

253

226

}

254

227

/* Special case of first server */

256

229

new_server->next = new_server;

257

230

new_server->prev = new_server;

258

231

*current_server = new_server;

232

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

259

233

} else {

260

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

261

234

new_server->next = *current_server;

262

235

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

263

236

new_server->prev->next = new_server;

264

237

(*current_server)->prev = new_server;

265

238

}

239

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

240

if(ret == -1){

241

perror_plus("clock_gettime");

242

return false;

243

}

266

244

return true;

267

245

}

268

246

269

247

/*

270

248

* Initialize GPGME.

271

249

*/

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){

250

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

251

const char *tempdir, mandos_context *mc){

277

252

gpgme_error_t rc;

278

253

gpgme_engine_info_t engine_info;

279

254

280

255

/*

281

256

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

282

257

*/

283

bool import_key(const char * const filename){

258

bool import_key(const char *filename){

284

259

int ret;

285

260

int fd;

286

261

gpgme_data_t pgp_data;

367

342

* Decrypt OpenPGP data.

368

343

* Returns -1 on error

369

344

*/

370

__attribute__((nonnull, warn_unused_result))

371

345

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

346

size_t crypto_size,

373

347

char **plaintext,

493

467

return plaintext_length;

494

468

}

495

469

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){

470

static const char * safer_gnutls_strerror(int value){

505

471

const char *ret = gnutls_strerror(value);

506

return safe_string(ret);

472

if(ret == NULL)

473

ret = "(unknown)";

474

return ret;

507

475

}

508

476

509

477

/* GnuTLS log function callback */

510

__attribute__((nonnull))

511

478

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

512

479

const char* string){

513

480

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

514

481

}

515

482

516

__attribute__((nonnull, warn_unused_result))

517

483

static int init_gnutls_global(const char *pubkeyfilename,

518

484

const char *seckeyfilename,

519

const char *dhparamsfilename,

520

485

mandos_context *mc){

521

486

int ret;

522

unsigned int uret;

523

487

524

488

if(debug){

525

489

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

576

540

safer_gnutls_strerror(ret));

577

541

goto globalfail;

578

542

}

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

}

543

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

544

if(ret != GNUTLS_E_SUCCESS){

545

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

546

safer_gnutls_strerror(ret));

547

goto globalfail;

548

}

549

751

550

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

752

551

753

552

return 0;

760

559

return -1;

761

560

}

762

561

763

__attribute__((nonnull, warn_unused_result))

764

562

static int init_gnutls_session(gnutls_session_t *session,

765

563

mandos_context *mc){

766

564

int ret;

813

611

/* ignore client certificate if any. */

814

612

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

815

613

614

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

615

816

616

return 0;

817

617

}

818

618

820

620

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

821

621

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

822

622

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

1040

623

/* Called when a Mandos server is found */

1041

__attribute__((nonnull, warn_unused_result))

1042

624

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

1043

625

AvahiIfIndex if_index,

1044

626

int af, mandos_context *mc){

1045

627

int ret, tcp_sd = -1;

1046

628

ssize_t sret;

1047

struct sockaddr_storage to;

629

union {

630

struct sockaddr_in in;

631

struct sockaddr_in6 in6;

632

} to;

1048

633

char *buffer = NULL;

1049

634

char *decrypted_buffer = NULL;

1050

635

size_t buffer_length = 0;

1053

638

int retval = -1;

1054

639

gnutls_session_t session;

1055

640

int pf; /* Protocol family */

1056

bool route_added = false;

1057

641

1058

642

errno = 0;

1059

643

1117

701

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

1118

702

}

1119

703

1120

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

704

tcp_sd = socket(pf, SOCK_STREAM, 0);

1121

705

if(tcp_sd < 0){

1122

706

int e = errno;

1123

707

perror_plus("socket");

1132

716

1133

717

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

1134

718

if(af == AF_INET6){

1135

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

1136

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

719

to.in6.sin6_family = (sa_family_t)af;

720

ret = inet_pton(af, ip, &to.in6.sin6_addr);

1137

721

} else { /* IPv4 */

1138

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

1139

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

722

to.in.sin_family = (sa_family_t)af;

723

ret = inet_pton(af, ip, &to.in.sin_addr);

1140

724

}

1141

725

if(ret < 0 ){

1142

726

int e = errno;

1151

735

goto mandos_end;

1152

736

}

1153

737

if(af == AF_INET6){

1154

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

1155

if(IN6_IS_ADDR_LINKLOCAL

1156

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

738

to.in6.sin6_port = htons(port);

739

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

740

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

741

-Wunreachable-code*/

1157

742

if(if_index == AVAHI_IF_UNSPEC){

1158

743

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

1159

744

" incomplete without a network interface\n");

1161

746

goto mandos_end;

1162

747

}

1163

748

/* Set the network interface number as scope */

1164

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

749

to.in6.sin6_scope_id = (uint32_t)if_index;

1165

750

}

1166

751

} else {

1167

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

752

to.in.sin_port = htons(port); /* Spurious warnings from

753

-Wconversion and

754

-Wunreachable-code */

1168

755

}

1169

756

1170

757

if(quit_now){

1187

774

}

1188

775

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1189

776

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1190

if(af == AF_INET6){

1191

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

1192

sizeof(struct sockaddr_in6),

1193

addrstr, sizeof(addrstr), NULL, 0,

1194

NI_NUMERICHOST);

1195

} else {

1196

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

1197

sizeof(struct sockaddr_in),

1198

addrstr, sizeof(addrstr), NULL, 0,

1199

NI_NUMERICHOST);

1200

}

1201

if(ret == EAI_SYSTEM){

1202

perror_plus("getnameinfo");

1203

} else if(ret != 0) {

1204

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

1205

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

1206

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

1207

}

1208

}

1209

1210

if(quit_now){

1211

errno = EINTR;

1212

goto mandos_end;

1213

}

1214

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;

777

const char *pcret;

778

if(af == AF_INET6){

779

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

780

sizeof(addrstr));

781

} else {

782

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

783

sizeof(addrstr));

784

}

785

if(pcret == NULL){

786

perror_plus("inet_ntop");

787

} else {

788

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

789

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

790

}

791

}

792

}

793

794

if(quit_now){

795

errno = EINTR;

796

goto mandos_end;

797

}

798

799

if(af == AF_INET6){

800

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

801

} else {

802

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

803

}

804

if(ret < 0){

805

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

806

int e = errno;

807

perror_plus("connect");

808

errno = e;

809

}

810

goto mandos_end;

811

}

812

813

if(quit_now){

814

errno = EINTR;

815

goto mandos_end;

1270

816

}

1271

817

1272

818

const char *out = mandos_protocol_version;

1455

1001

1456

1002

mandos_end:

1457

1003

{

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

}

1464

1004

int e = errno;

1465

1005

free(decrypted_buffer);

1466

1006

free(buffer);

1483

1023

return retval;

1484

1024

}

1485

1025

1486

__attribute__((nonnull))

1487

1026

static void resolve_callback(AvahiSServiceResolver *r,

1488

1027

AvahiIfIndex interface,

1489

1028

AvahiProtocol proto,

1497

1036

AVAHI_GCC_UNUSED AvahiStringList *txt,

1498

1037

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1499

1038

flags,

1500

void *mc){

1039

void* mc){

1501

1040

if(r == NULL){

1502

1041

return;

1503

1042

}

1506

1045

timed out */

1507

1046

1508

1047

if(quit_now){

1509

avahi_s_service_resolver_free(r);

1510

1048

return;

1511

1049

}

1512

1050

1557

1095

const char *domain,

1558

1096

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1559

1097

flags,

1560

void *mc){

1098

void* mc){

1561

1099

if(b == NULL){

1562

1100

return;

1563

1101

}

1623

1161

errno = old_errno;

1624

1162

}

1625

1163

1626

__attribute__((nonnull, warn_unused_result))

1627

1164

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

1628

1165

int ret;

1629

1166

error_t ret_errno;

1648

1185

return true;

1649

1186

}

1650

1187

1651

__attribute__((nonnull, warn_unused_result))

1652

1188

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

1653

1189

1654

1190

/* Reject the loopback device */

1696

1232

* corresponds to an acceptable network device.

1697

1233

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

1698

1234

*/

1699

__attribute__((nonnull, warn_unused_result))

1700

1235

int good_interface(const struct dirent *if_entry){

1701

1236

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

1702

1237

return 0;

1720

1255

/*

1721

1256

* This function determines if a network interface is up.

1722

1257

*/

1723

__attribute__((nonnull, warn_unused_result))

1724

1258

bool interface_is_up(const char *interface){

1725

1259

struct ifreq ifr;

1726

1260

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

1737

1271

/*

1738

1272

* This function determines if a network interface is running

1739

1273

*/

1740

__attribute__((nonnull, warn_unused_result))

1741

1274

bool interface_is_running(const char *interface){

1742

1275

struct ifreq ifr;

1743

1276

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

1751

1284

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

1752

1285

}

1753

1286

1754

__attribute__((nonnull, pure, warn_unused_result))

1755

1287

int notdotentries(const struct dirent *direntry){

1756

1288

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

1757

1289

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

1764

1296

}

1765

1297

1766

1298

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

1767

__attribute__((nonnull, warn_unused_result))

1768

1299

int runnable_hook(const struct dirent *direntry){

1769

1300

int ret;

1770

1301

size_t sret;

1778

1309

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

1779

1310

"abcdefghijklmnopqrstuvwxyz"

1780

1311

"0123456789"

1781

"_.-");

1312

"_-");

1782

1313

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

1783

1314

/* Contains non-allowed characters */

1784

1315

if(debug){

1788

1319

return 0;

1789

1320

}

1790

1321

1791

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

1322

char *fullname = NULL;

1323

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

1324

if(ret < 0){

1325

perror_plus("asprintf");

1326

return 0;

1327

}

1328

1329

ret = stat(fullname, &st);

1792

1330

if(ret == -1){

1793

1331

if(debug){

1794

1332

perror_plus("Could not stat hook");

1818

1356

return 1;

1819

1357

}

1820

1358

1821

__attribute__((nonnull, warn_unused_result))

1822

1359

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1823

1360

mandos_context *mc){

1824

1361

int ret;

1828

1365

1829

1366

while(true){

1830

1367

if(mc->current_server == NULL){

1831

if(debug){

1368

if (debug){

1832

1369

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

1833

1370

" No timeout!\n");

1834

1371

}

1835

1372

ret = avahi_simple_poll_iterate(s, -1);

1836

1373

} else {

1837

if(debug){

1374

if (debug){

1838

1375

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

1839

1376

" it, or wait\n");

1840

1377

}

1857

1394

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

1858

1395

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

1859

1396

1860

if(debug){

1397

if (debug){

1861

1398

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

1862

1399

block_time);

1863

1400

}

1885

1422

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

1886

1423

}

1887

1424

if(ret != 0){

1888

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

1425

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

1889

1426

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

1890

1427

}

1891

1428

}

1892

1429

}

1893

1430

}

1894

1431

1895

__attribute__((nonnull))

1896

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

1432

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

1433

error_t raise_privileges(void){

1434

error_t old_errno = errno;

1435

error_t ret_errno = 0;

1436

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

1437

ret_errno = errno;

1438

perror_plus("seteuid");

1439

}

1440

errno = old_errno;

1441

return ret_errno;

1442

}

1443

1444

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

1445

error_t raise_privileges_permanently(void){

1446

error_t old_errno = errno;

1447

error_t ret_errno = raise_privileges();

1448

if(ret_errno != 0){

1449

errno = old_errno;

1450

return ret_errno;

1451

}

1452

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

1453

ret_errno = errno;

1454

perror_plus("seteuid");

1455

}

1456

errno = old_errno;

1457

return ret_errno;

1458

}

1459

1460

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

1461

error_t lower_privileges(void){

1462

error_t old_errno = errno;

1463

error_t ret_errno = 0;

1464

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

1465

ret_errno = errno;

1466

perror_plus("seteuid");

1467

}

1468

errno = old_errno;

1469

return ret_errno;

1470

}

1471

1472

/* Lower privileges permanently */

1473

error_t lower_privileges_permanently(void){

1474

error_t old_errno = errno;

1475

error_t ret_errno = 0;

1476

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

1477

ret_errno = errno;

1478

perror_plus("setuid");

1479

}

1480

errno = old_errno;

1481

return ret_errno;

1482

}

1483

1484

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

1897

1485

const float delay){

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__ */

1486

struct dirent **direntries;

1487

struct dirent *direntry;

1488

int ret;

1489

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

1490

alphasort);

1926

1491

if(numhooks == -1){

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);

1492

if(errno == ENOENT){

1493

if(debug){

1494

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

1495

" found\n", hookdir);

1496

}

1497

} else {

1498

perror_plus("scandir");

1942

1499

}

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){

1500

} else {

1501

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

1502

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

1503

direntry = direntries[i];

1504

char *fullname = NULL;

1505

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

1506

if(ret < 0){

1989

1507

perror_plus("asprintf");

1990

_exit(EX_OSERR);

1991

}

1992

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

1993

if(ret == -1){

1508

continue;

1509

}

1510

if(debug){

1511

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

1512

direntry->d_name);

1513

}

1514

pid_t hook_pid = fork();

1515

if(hook_pid == 0){

1516

/* Child */

1517

/* Raise privileges */

1518

raise_privileges_permanently();

1519

/* Set group */

1520

errno = 0;

1521

ret = setgid(0);

1522

if(ret == -1){

1523

perror_plus("setgid");

1524

}

1525

/* Reset supplementary groups */

1526

errno = 0;

1527

ret = setgroups(0, NULL);

1528

if(ret == -1){

1529

perror_plus("setgroups");

1530

}

1531

dup2(devnull, STDIN_FILENO);

1532

close(devnull);

1533

dup2(STDERR_FILENO, STDOUT_FILENO);

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

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

1540

if(ret == -1){

1541

perror_plus("setenv");

1542

_exit(EX_OSERR);

1543

}

1544

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

1545

if(ret == -1){

1546

perror_plus("setenv");

1547

_exit(EX_OSERR);

1548

}

1549

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

1550

if(ret == -1){

1551

perror_plus("setenv");

1552

_exit(EX_OSERR);

1553

}

1554

char *delaystring;

1555

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

1556

if(ret == -1){

1557

perror_plus("asprintf");

1558

_exit(EX_OSERR);

1559

}

1560

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

1561

if(ret == -1){

1562

free(delaystring);

1563

perror_plus("setenv");

1564

_exit(EX_OSERR);

1565

}

1994

1566

free(delaystring);

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;

1567

if(connect_to != NULL){

1568

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

1569

if(ret == -1){

1570

perror_plus("setenv");

1571

_exit(EX_OSERR);

1572

}

1573

}

1574

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

1575

perror_plus("execl");

1576

_exit(EXIT_FAILURE);

1577

}

2063

1578

} else {

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);

1579

int status;

1580

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

1581

perror_plus("waitpid");

1582

free(fullname);

1583

continue;

1584

}

1585

if(WIFEXITED(status)){

1586

if(WEXITSTATUS(status) != 0){

1587

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

1588

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

1589

WEXITSTATUS(status));

1590

free(fullname);

1591

continue;

1592

}

1593

} else if(WIFSIGNALED(status)){

1594

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

1595

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

1596

WTERMSIG(status));

1597

free(fullname);

1598

continue;

1599

} else {

1600

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

1601

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

1602

free(fullname);

1603

continue;

1604

}

1605

}

1606

free(fullname);

1607

if(debug){

1608

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

1609

direntry->d_name);

1610

}

1611

}

1612

close(devnull);

1613

}

1614

return true;

2083

1615

}

2084

1616

2085

__attribute__((nonnull, warn_unused_result))

2086

1617

error_t bring_up_interface(const char *const interface,

2087

1618

const float delay){

1619

int sd = -1;

2088

1620

error_t old_errno = errno;

2089

int ret;

1621

error_t ret_errno = 0;

1622

int ret, ret_setflags;

2090

1623

struct ifreq network;

2091

1624

unsigned int if_index = if_nametoindex(interface);

2092

1625

if(if_index == 0){

2101

1634

}

2102

1635

2103

1636

if(not interface_is_up(interface)){

2104

error_t ret_errno = 0, ioctl_errno = 0;

2105

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

1637

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

2106

1638

ret_errno = errno;

2107

1639

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

2108

1640

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

2109

errno = old_errno;

2110

1641

return ret_errno;

2111

1642

}

2112

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

1643

network.ifr_flags |= IFF_UP;

2113

1644

2114

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

2115

if(sd == -1){

1645

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1646

if(sd < 0){

2116

1647

ret_errno = errno;

2117

1648

perror_plus("socket");

2118

1649

errno = old_errno;

2119

1650

return ret_errno;

2120

1651

}

2121

1652

2122

1653

if(quit_now){

2123

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

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

1654

close(sd);

2127

1655

errno = old_errno;

2128

1656

return EINTR;

2129

1657

}

2133

1661

interface);

2134

1662

}

2135

1663

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

}

1664

/* Raise priviliges */

1665

raise_privileges();

2142

1666

2143

1667

#ifdef __linux__

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

}

1668

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1669

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

1670

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

1671

bool restore_loglevel = true;

1672

if(ret_linux == -1){

1673

restore_loglevel = false;

1674

perror_plus("klogctl");

2155

1675

}

2156

1676

#endif /* __linux__ */

2157

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

2158

ioctl_errno = errno;

1677

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

1678

ret_errno = errno;

2159

1679

#ifdef __linux__

2160

1680

if(restore_loglevel){

2161

1681

ret_linux = klogctl(7, NULL, 0);

2165

1685

}

2166

1686

#endif /* __linux__ */

2167

1687

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

}

1688

/* Lower privileges */

1689

lower_privileges();

2177

1690

2178

1691

/* Close the socket */

2179

1692

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

2182

1695

}

2183

1696

2184

1697

if(ret_setflags == -1){

2185

errno = ioctl_errno;

1698

errno = ret_errno;

2186

1699

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2187

1700

errno = old_errno;

2188

return ioctl_errno;

1701

return ret_errno;

2189

1702

}

2190

1703

} else if(debug){

2191

1704

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

2209

1722

return 0;

2210

1723

}

2211

1724

2212

__attribute__((nonnull, warn_unused_result))

2213

1725

error_t take_down_interface(const char *const interface){

1726

int sd = -1;

2214

1727

error_t old_errno = errno;

1728

error_t ret_errno = 0;

1729

int ret, ret_setflags;

2215

1730

struct ifreq network;

2216

1731

unsigned int if_index = if_nametoindex(interface);

2217

1732

if(if_index == 0){

2220

1735

return ENXIO;

2221

1736

}

2222

1737

if(interface_is_up(interface)){

2223

error_t ret_errno = 0, ioctl_errno = 0;

2224

1738

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

2225

1739

ret_errno = errno;

2226

1740

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

2227

1741

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

2228

errno = old_errno;

2229

1742

return ret_errno;

2230

1743

}

2231

1744

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

2232

1745

2233

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

2234

if(sd == -1){

1746

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1747

if(sd < 0){

2235

1748

ret_errno = errno;

2236

1749

perror_plus("socket");

2237

1750

errno = old_errno;

2243

1756

interface);

2244

1757

}

2245

1758

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

}

2252

2253

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

2254

ioctl_errno = errno;

2255

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

}

1759

/* Raise priviliges */

1760

raise_privileges();

1761

1762

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

1763

ret_errno = errno;

1764

1765

/* Lower privileges */

1766

lower_privileges();

2265

1767

2266

1768

/* Close the socket */

2267

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

1769

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

2268

1770

if(ret == -1){

2269

1771

perror_plus("close");

2270

1772

}

2271

1773

2272

1774

if(ret_setflags == -1){

2273

errno = ioctl_errno;

1775

errno = ret_errno;

2274

1776

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2275

1777

errno = old_errno;

2276

return ioctl_errno;

1778

return ret_errno;

2277

1779

}

2278

1780

} else if(debug){

2279

1781

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

2285

1787

}

2286

1788

2287

1789

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

2288

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

1790

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

2289

1791

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

2290

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

1792

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

2291

1793

.interfaces = NULL, .interfaces_size = 0 };

2292

1794

AvahiSServiceBrowser *sb = NULL;

2293

1795

error_t ret_errno;

2297

1799

int exitcode = EXIT_SUCCESS;

2298

1800

char *interfaces_to_take_down = NULL;

2299

1801

size_t interfaces_to_take_down_size = 0;

2300

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

2301

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

2302

char *tempdir = NULL;

1802

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

1803

bool tempdir_created = false;

2303

1804

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2304

1805

const char *seckey = PATHDIR "/" SECKEY;

2305

1806

const char *pubkey = PATHDIR "/" PUBKEY;

2306

const char *dh_params_file = NULL;

2307

1807

char *interfaces_hooks = NULL;

1808

size_t interfaces_hooks_size = 0;

2308

1809

2309

1810

bool gnutls_initialized = false;

2310

1811

bool gpgme_initialized = false;

2362

1863

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

2363

1864

" Diffie-Hellman key exchange",

2364

1865

.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 },

2370

1866

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

2371

1867

.arg = "STRING",

2372

1868

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

2427

1923

}

2428

1924

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

2429

1925

break;

2430

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

2431

dh_params_file = arg;

2432

break;

2433

1926

case 130: /* --priority */

2434

1927

mc.priority = arg;

2435

1928

break;

2491

1984

goto end;

2492

1985

}

2493

1986

}

2494

1987

2495

1988

{

2496

1989

/* Work around Debian bug #633582:

2497

1990

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

2498

1991

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 {

1992

/* Re-raise priviliges */

1993

if(raise_privileges() == 0){

2505

1994

struct stat st;

2506

1995

2507

1996

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

2524

2013

TEMP_FAILURE_RETRY(close(seckey_fd));

2525

2014

}

2526

2015

}

2527

2016

2528

2017

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

2529

2018

int pubkey_fd = open(pubkey, O_RDONLY);

2530

2019

if(pubkey_fd == -1){

2545

2034

TEMP_FAILURE_RETRY(close(pubkey_fd));

2546

2035

}

2547

2036

}

2548

2037

2549

2038

/* Lower privileges */

2550

ret_errno = lower_privileges();

2551

if(ret_errno != 0){

2552

errno = ret_errno;

2553

perror_plus("Failed to lower privileges");

2554

}

2039

lower_privileges();

2555

2040

}

2556

2041

}

2557

2042

2581

2066

goto end;

2582

2067

}

2583

2068

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

2584

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

2585

}

2586

run_network_hooks("start", interfaces_hooks != NULL ?

2587

interfaces_hooks : "", delay);

2069

interfaces_hooks_size = mc.interfaces_size;

2070

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2071

(int)',');

2072

}

2073

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

2074

interfaces_hooks : "", delay)){

2075

goto end;

2076

}

2588

2077

}

2589

2078

2590

2079

if(not debug){

2668

2157

2669

2158

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

2670

2159

if(mc.interfaces == NULL){

2671

struct dirent **direntries = NULL;

2160

struct dirent **direntries;

2672

2161

/* Look for any good interfaces */

2673

2162

ret = scandir(sys_class_net, &direntries, good_interface,

2674

2163

alphasort);

2678

2167

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

2679

2168

direntries[i]->d_name);

2680

2169

if(ret_errno != 0){

2681

errno = ret_errno;

2682

2170

perror_plus("argz_add");

2683

free(direntries[i]);

2684

2171

continue;

2685

2172

}

2686

2173

if(debug){

2687

2174

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

2688

2175

direntries[i]->d_name);

2689

2176

}

2690

free(direntries[i]);

2691

2177

}

2692

2178

free(direntries);

2693

2179

} else {

2694

if(ret == 0){

2695

free(direntries);

2696

}

2180

free(direntries);

2697

2181

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

2698

2182

exitcode = EXIT_FAILURE;

2699

2183

goto end;

2722

2206

break;

2723

2207

}

2724

2208

bool interface_was_up = interface_is_up(interface);

2725

errno = bring_up_interface(interface, delay);

2209

ret = bring_up_interface(interface, delay);

2726

2210

if(not interface_was_up){

2727

if(errno != 0){

2211

if(ret != 0){

2212

errno = ret;

2728

2213

perror_plus("Failed to bring up interface");

2729

2214

} else {

2730

errno = argz_add(&interfaces_to_take_down,

2731

&interfaces_to_take_down_size,

2732

interface);

2733

if(errno != 0){

2734

perror_plus("argz_add");

2735

}

2215

ret_errno = argz_add(&interfaces_to_take_down,

2216

&interfaces_to_take_down_size,

2217

interface);

2736

2218

}

2737

2219

}

2738

2220

}

2754

2236

goto end;

2755

2237

}

2756

2238

2757

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

2239

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

2758

2240

if(ret == -1){

2759

2241

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

2760

2242

exitcode = EX_UNAVAILABLE;

2767

2249

goto end;

2768

2250

}

2769

2251

2770

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

2771

tempdir = mkdtemp(run_tempdir);

2772

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

2773

if(debug){

2774

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

2775

run_tempdir, old_tempdir);

2776

}

2777

tempdir = mkdtemp(old_tempdir);

2778

}

2779

if(tempdir == NULL){

2252

if(mkdtemp(tempdir) == NULL){

2780

2253

perror_plus("mkdtemp");

2781

2254

goto end;

2782

2255

}

2256

tempdir_created = true;

2783

2257

2784

2258

if(quit_now){

2785

2259

goto end;

2857

2331

fprintf_plus(stderr, "Retrying in %d seconds\n",

2858

2332

(int)retry_interval);

2859

2333

}

2860

sleep((unsigned int)retry_interval);

2334

sleep((int)retry_interval);

2861

2335

}

2862

2336

2863

if(not quit_now){

2337

if (not quit_now){

2864

2338

exitcode = EXIT_SUCCESS;

2865

2339

}

2866

2340

2921

2395

if(debug){

2922

2396

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

2923

2397

}

2924

2398

2925

2399

ret = avahi_loop_with_timeout(simple_poll,

2926

2400

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

2927

2401

if(debug){

2963

2437

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

2964

2438

while(mc.current_server != NULL){

2965

2439

server *next = mc.current_server->next;

2966

#ifdef __GNUC__

2967

#pragma GCC diagnostic push

2968

#pragma GCC diagnostic ignored "-Wcast-qual"

2969

#endif

2970

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

2971

#ifdef __GNUC__

2972

#pragma GCC diagnostic pop

2973

#endif

2974

2440

free(mc.current_server);

2975

2441

mc.current_server = next;

2976

2442

}

2977

2443

}

2978

2444

2979

/* Re-raise privileges */

2445

/* Re-raise priviliges */

2980

2446

{

2981

ret_errno = raise_privileges();

2982

if(ret_errno != 0){

2983

errno = ret_errno;

2984

perror_plus("Failed to raise privileges");

2985

} else {

2986

2987

/* Run network hooks */

2988

run_network_hooks("stop", interfaces_hooks != NULL ?

2989

interfaces_hooks : "", delay);

2990

2991

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

2992

{

2993

char *interface = NULL;

2994

while((interface=argz_next(interfaces_to_take_down,

2995

interfaces_to_take_down_size,

2996

interface))){

2997

ret_errno = take_down_interface(interface);

2998

if(ret_errno != 0){

2999

errno = ret_errno;

3000

perror_plus("Failed to take down interface");

3001

}

3002

}

3003

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

3004

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

3005

" down\n");

3006

}

3007

}

3008

}

3009

3010

ret_errno = lower_privileges_permanently();

3011

if(ret_errno != 0){

3012

errno = ret_errno;

3013

perror_plus("Failed to lower privileges permanently");

3014

}

2447

raise_privileges();

2448

2449

/* Run network hooks */

2450

run_network_hooks("stop", interfaces_hooks != NULL ?

2451

interfaces_hooks : "", delay);

2452

2453

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

2454

{

2455

char *interface = NULL;

2456

while((interface=argz_next(interfaces_to_take_down,

2457

interfaces_to_take_down_size,

2458

interface))){

2459

ret_errno = take_down_interface(interface);

2460

if(ret_errno != 0){

2461

errno = ret_errno;

2462

perror_plus("Failed to take down interface");

2463

}

2464

}

2465

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

2466

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

2467

" down\n");

2468

}

2469

}

2470

2471

lower_privileges_permanently();

3015

2472

}

3016

2473

3017

2474

free(interfaces_to_take_down);

3018

2475

free(interfaces_hooks);

3019

2476

3020

2477

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

3021

if(tempdir != NULL){

2478

if(tempdir_created){

3022

2479

struct dirent **direntries = NULL;

3023

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

3024

| O_NOFOLLOW

3025

| O_DIRECTORY

3026

| O_PATH));

3027

if(tempdir_fd == -1){

3028

perror_plus("open");

3029

} else {

3030

#ifdef __GLIBC__

3031

#if __GLIBC_PREREQ(2, 15)

3032

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

3033

notdotentries, alphasort);

3034

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

3035

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

3036

alphasort);

3037

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

3038

#else /* not __GLIBC__ */

3039

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

3040

alphasort);

3041

#endif /* not __GLIBC__ */

3042

if(numentries >= 0){

3043

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

3044

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

3045

if(ret == -1){

3046

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

3047

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

3048

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

3049

}

3050

free(direntries[i]);

3051

}

3052

3053

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

3054

free(direntries);

3055

if(numentries == -1){

3056

perror_plus("scandir");

3057

}

3058

ret = rmdir(tempdir);

3059

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

3060

perror_plus("rmdir");

3061

}

2480

struct dirent *direntry = NULL;

2481

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

2482

alphasort);

2483

if (numentries > 0){

2484

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

2485

direntry = direntries[i];

2486

char *fullname = NULL;

2487

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

2488

direntry->d_name);

2489

if(ret < 0){

2490

perror_plus("asprintf");

2491

continue;

2492

}

2493

ret = remove(fullname);

2494

if(ret == -1){

2495

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

2496

strerror(errno));

2497

}

2498

free(fullname);

3062

2499

}

3063

TEMP_FAILURE_RETRY(close(tempdir_fd));

2500

}

2501

2502

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

2503

free(direntries);

2504

if (numentries == -1){

2505

perror_plus("scandir");

2506

}

2507

ret = rmdir(tempdir);

2508

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

2509

perror_plus("rmdir");

3064

2510

}

3065

2511

}

3066

2512