/mandos/release : revision 237.7.309

9

* "browse_callback", and parts of "main".

10

*

11

* Everything else is

12

13

12

13

14

*

15

* This program is free software: you can redistribute it and/or

16

* modify it under the terms of the GNU General Public License as

32

/* Needed by GPGME, specifically gpgme_data_seek() */

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif

35

#endif /* not _LARGEFILE_SOURCE */

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif

38

#endif /* not _FILE_OFFSET_BITS */

39

40

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

41

42

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

43

stdout, ferror(), remove() */

43

stdout, ferror() */

44

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

45

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

46

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

57

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

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

61

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

62

*/

63

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

73

*/

74

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

75

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

76

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

76

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

77

unlinkat() */

77

78

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

78

79

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

79

80

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

141

142

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

142

143

char *connect_to = NULL;

143

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

144

146

uid_t uid = 65534;

145

147

gid_t gid = 65534;

146

148

183

185

perror(print_text);

184

186

}

185

187

186

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

188

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

187

189

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

188

190

va_list ap;

189

191

va_start (ap, format);

198

200

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

199

201

* "buffer_length" is how much is already used.

200

202

*/

203

__attribute__((nonnull, warn_unused_result))

201

204

size_t incbuffer(char **buffer, size_t buffer_length,

202

205

size_t buffer_capacity){

203

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

216

219

}

217

220

218

221

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

222

__attribute__((nonnull, warn_unused_result))

219

223

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

220

224

int af, server **current_server){

221

225

int ret;

230

234

.af = af };

231

235

if(new_server->ip == NULL){

232

236

perror_plus("strdup");

237

free(new_server);

233

238

return false;

234

239

}

235

240

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

236

241

if(ret == -1){

237

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

238

252

return false;

239

253

}

240

254

/* Special case of first server */

242

256

new_server->next = new_server;

243

257

new_server->prev = new_server;

244

258

*current_server = new_server;

245

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

246

259

} else {

260

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

247

261

new_server->next = *current_server;

248

262

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

249

263

new_server->prev->next = new_server;

255

269

/*

256

270

* Initialize GPGME.

257

271

*/

258

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

259

const char *tempdir, mandos_context *mc){

272

__attribute__((nonnull, warn_unused_result))

273

static bool init_gpgme(const char * const seckey,

274

const char * const pubkey,

275

const char * const tempdir,

276

mandos_context *mc){

260

277

gpgme_error_t rc;

261

278

gpgme_engine_info_t engine_info;

262

279

263

280

/*

264

281

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

265

282

*/

266

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

267

284

int ret;

268

285

int fd;

269

286

gpgme_data_t pgp_data;

350

367

* Decrypt OpenPGP data.

351

368

* Returns -1 on error

352

369

*/

370

__attribute__((nonnull, warn_unused_result))

353

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

354

372

size_t crypto_size,

355

373

char **plaintext,

475

493

return plaintext_length;

476

494

}

477

495

478

static const char * safer_gnutls_strerror(int value){

496

__attribute__((warn_unused_result, const))

497

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

498

if(str == NULL)

499

return "(unknown)";

500

return str;

501

}

502

503

__attribute__((warn_unused_result))

504

static const char *safer_gnutls_strerror(int value){

479

505

const char *ret = gnutls_strerror(value);

480

if(ret == NULL)

481

ret = "(unknown)";

482

return ret;

506

return safe_string(ret);

483

507

}

484

508

485

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

486

511

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

487

512

const char* string){

488

513

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

489

514

}

490

515

516

__attribute__((nonnull, warn_unused_result))

491

517

static int init_gnutls_global(const char *pubkeyfilename,

492

518

const char *seckeyfilename,

493

519

mandos_context *mc){

494

520

int ret;

521

unsigned int uret;

495

522

496

523

if(debug){

497

524

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

548

575

safer_gnutls_strerror(ret));

549

576

goto globalfail;

550

577

}

578

if(mc->dh_bits == 0){

579

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

580

/* Try to read the private key file */

581

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

582

{

583

int secfile = open(seckeyfilename, O_RDONLY);

584

size_t buffer_capacity = 0;

585

while(true){

586

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

587

(size_t)buffer.size,

588

(size_t)buffer_capacity);

589

if(buffer_capacity == 0){

590

perror_plus("incbuffer");

591

free(buffer.data);

592

buffer.data = NULL;

593

break;

594

}

595

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

596

BUFFER_SIZE);

597

/* EOF */

598

if(bytes_read == 0){

599

break;

600

}

601

/* check bytes_read for failure */

602

if(bytes_read < 0){

603

perror_plus("read");

604

free(buffer.data);

605

buffer.data = NULL;

606

break;

607

}

608

buffer.size += (unsigned int)bytes_read;

609

}

610

close(secfile);

611

}

612

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

613

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

614

if(buffer.data != NULL){

615

{

616

gnutls_openpgp_privkey_t privkey = NULL;

617

ret = gnutls_openpgp_privkey_init(&privkey);

618

if(ret != GNUTLS_E_SUCCESS){

619

fprintf_plus(stderr, "Error initializing OpenPGP key"

620

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

621

free(buffer.data);

622

buffer.data = NULL;

623

} else {

624

ret = gnutls_openpgp_privkey_import(privkey, &buffer,

625

GNUTLS_OPENPGP_FMT_BASE64,

626

"", 0);

627

if(ret != GNUTLS_E_SUCCESS){

628

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

629

safer_gnutls_strerror(ret));

630

privkey = NULL;

631

}

632

free(buffer.data);

633

buffer.data = NULL;

634

if(privkey != NULL){

635

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

636

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

637

gnutls_openpgp_privkey_deinit(privkey);

638

if(debug){

639

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

640

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

641

safe_string(gnutls_sec_param_get_name

642

(sec_param)));

643

}

644

}

645

}

646

}

647

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

648

/* Err on the side of caution */

649

sec_param = GNUTLS_SEC_PARAM_ULTRA;

650

if(debug){

651

fprintf_plus(stderr, "Falling back to security parameter"

652

" \"%s\"\n",

653

safe_string(gnutls_sec_param_get_name

654

(sec_param)));

655

}

656

}

657

}

658

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

659

if(uret != 0){

660

mc->dh_bits = uret;

661

if(debug){

662

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

663

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

664

safe_string(gnutls_sec_param_get_name

665

(sec_param)),

666

mc->dh_bits);

667

}

668

} else {

669

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

670

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

671

safe_string(gnutls_sec_param_get_name(sec_param)),

672

safer_gnutls_strerror(ret));

673

goto globalfail;

674

}

675

} else if(debug){

676

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

677

mc->dh_bits);

678

}

551

679

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

552

680

if(ret != GNUTLS_E_SUCCESS){

553

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

554

safer_gnutls_strerror(ret));

681

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

682

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

555

683

goto globalfail;

556

684

}

557

685

567

695

return -1;

568

696

}

569

697

698

__attribute__((nonnull, warn_unused_result))

570

699

static int init_gnutls_session(gnutls_session_t *session,

571

700

mandos_context *mc){

572

701

int ret;

628

757

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

629

758

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

630

759

760

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

761

__attribute__((warn_unused_result))

762

error_t raise_privileges(void){

763

error_t old_errno = errno;

764

error_t ret_errno = 0;

765

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

766

ret_errno = errno;

767

}

768

errno = old_errno;

769

return ret_errno;

770

}

771

772

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

773

__attribute__((warn_unused_result))

774

error_t raise_privileges_permanently(void){

775

error_t old_errno = errno;

776

error_t ret_errno = raise_privileges();

777

if(ret_errno != 0){

778

errno = old_errno;

779

return ret_errno;

780

}

781

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

782

ret_errno = errno;

783

}

784

errno = old_errno;

785

return ret_errno;

786

}

787

788

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

789

__attribute__((warn_unused_result))

790

error_t lower_privileges(void){

791

error_t old_errno = errno;

792

error_t ret_errno = 0;

793

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

794

ret_errno = errno;

795

}

796

errno = old_errno;

797

return ret_errno;

798

}

799

800

/* Lower privileges permanently */

801

__attribute__((warn_unused_result))

802

error_t lower_privileges_permanently(void){

803

error_t old_errno = errno;

804

error_t ret_errno = 0;

805

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

806

ret_errno = errno;

807

}

808

errno = old_errno;

809

return ret_errno;

810

}

811

812

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

813

__attribute__((nonnull, warn_unused_result))

814

static bool add_delete_local_route(const bool add,

815

const char *address,

816

AvahiIfIndex if_index){

817

int ret;

818

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

819

char add_arg[] = "add";

820

char delete_arg[] = "delete";

821

char debug_flag[] = "--debug";

822

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

823

if(pluginhelperdir == NULL){

824

if(debug){

825

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

826

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

827

}

828

return false;

829

}

830

831

char interface[IF_NAMESIZE];

832

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

833

perror_plus("if_indextoname");

834

return false;

835

}

836

837

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

838

if(devnull == -1){

839

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

840

return false;

841

}

842

pid_t pid = fork();

843

if(pid == 0){

844

/* Child */

845

/* Raise privileges */

846

errno = raise_privileges_permanently();

847

if(errno != 0){

848

perror_plus("Failed to raise privileges");

849

/* _exit(EX_NOPERM); */

850

} else {

851

/* Set group */

852

errno = 0;

853

ret = setgid(0);

854

if(ret == -1){

855

perror_plus("setgid");

856

_exit(EX_NOPERM);

857

}

858

/* Reset supplementary groups */

859

errno = 0;

860

ret = setgroups(0, NULL);

861

if(ret == -1){

862

perror_plus("setgroups");

863

_exit(EX_NOPERM);

864

}

865

}

866

ret = dup2(devnull, STDIN_FILENO);

867

if(ret == -1){

868

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

869

_exit(EX_OSERR);

870

}

871

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

872

if(ret == -1){

873

perror_plus("close");

874

_exit(EX_OSERR);

875

}

876

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

877

if(ret == -1){

878

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

879

_exit(EX_OSERR);

880

}

881

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

882

O_RDONLY

883

| O_DIRECTORY

884

| O_PATH

885

| O_CLOEXEC));

886

if(helperdir_fd == -1){

887

perror_plus("open");

888

_exit(EX_UNAVAILABLE);

889

}

890

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

891

helper, O_RDONLY));

892

if(helper_fd == -1){

893

perror_plus("openat");

894

_exit(EX_UNAVAILABLE);

895

}

896

TEMP_FAILURE_RETRY(close(helperdir_fd));

897

#ifdef __GNUC__

898

#pragma GCC diagnostic push

899

#pragma GCC diagnostic ignored "-Wcast-qual"

900

#endif

901

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

902

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

903

interface, debug ? debug_flag : NULL, NULL },

904

environ) == -1){

905

#ifdef __GNUC__

906

#pragma GCC diagnostic pop

907

#endif

908

perror_plus("fexecve");

909

_exit(EXIT_FAILURE);

910

}

911

}

912

if(pid == -1){

913

perror_plus("fork");

914

return false;

915

}

916

int status;

917

pid_t pret = -1;

918

errno = 0;

919

do {

920

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

921

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

922

int errno_raising = 0;

923

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

924

errno_raising = errno;

925

perror_plus("Failed to raise privileges in order to"

926

" kill helper program");

927

}

928

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

929

perror_plus("kill");

930

}

931

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

932

perror_plus("Failed to lower privileges after killing"

933

" helper program");

934

}

935

return false;

936

}

937

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

938

if(pret == -1){

939

perror_plus("waitpid");

940

return false;

941

}

942

if(WIFEXITED(status)){

943

if(WEXITSTATUS(status) != 0){

944

fprintf_plus(stderr, "Error: iprouteadddel exited"

945

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

946

return false;

947

}

948

return true;

949

}

950

if(WIFSIGNALED(status)){

951

fprintf_plus(stderr, "Error: iprouteadddel died by"

952

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

953

return false;

954

}

955

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

956

return false;

957

}

958

959

__attribute__((nonnull, warn_unused_result))

960

static bool add_local_route(const char *address,

961

AvahiIfIndex if_index){

962

if(debug){

963

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

964

}

965

return add_delete_local_route(true, address, if_index);

966

}

967

968

__attribute__((nonnull, warn_unused_result))

969

static bool delete_local_route(const char *address,

970

AvahiIfIndex if_index){

971

if(debug){

972

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

973

}

974

return add_delete_local_route(false, address, if_index);

975

}

976

631

977

/* Called when a Mandos server is found */

978

__attribute__((nonnull, warn_unused_result))

632

979

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

633

980

AvahiIfIndex if_index,

634

981

int af, mandos_context *mc){

635

982

int ret, tcp_sd = -1;

636

983

ssize_t sret;

637

union {

638

struct sockaddr_in in;

639

struct sockaddr_in6 in6;

640

} to;

984

struct sockaddr_storage to;

641

985

char *buffer = NULL;

642

986

char *decrypted_buffer = NULL;

643

987

size_t buffer_length = 0;

646

990

int retval = -1;

647

991

gnutls_session_t session;

648

992

int pf; /* Protocol family */

993

bool route_added = false;

649

994

650

995

errno = 0;

651

996

709

1054

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

710

1055

}

711

1056

712

tcp_sd = socket(pf, SOCK_STREAM, 0);

1057

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

713

1058

if(tcp_sd < 0){

714

1059

int e = errno;

715

1060

perror_plus("socket");

724

1069

725

1070

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

726

1071

if(af == AF_INET6){

727

to.in6.sin6_family = (sa_family_t)af;

728

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

1072

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

1073

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

729

1074

} else { /* IPv4 */

730

to.in.sin_family = (sa_family_t)af;

731

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

1075

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

1076

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

732

1077

}

733

1078

if(ret < 0 ){

734

1079

int e = errno;

743

1088

goto mandos_end;

744

1089

}

745

1090

if(af == AF_INET6){

746

to.in6.sin6_port = htons(port);

747

#ifdef __GNUC__

748

#pragma GCC diagnostic push

749

#pragma GCC diagnostic ignored "-Wstrict-aliasing"

750

#endif

751

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

752

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

753

#ifdef __GNUC__

754

#pragma GCC diagnostic pop

755

#endif

1091

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

1092

if(IN6_IS_ADDR_LINKLOCAL

1093

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

756

1094

if(if_index == AVAHI_IF_UNSPEC){

757

1095

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

758

1096

" incomplete without a network interface\n");

760

1098

goto mandos_end;

761

1099

}

762

1100

/* Set the network interface number as scope */

763

to.in6.sin6_scope_id = (uint32_t)if_index;

1101

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

764

1102

}

765

1103

} else {

766

to.in.sin_port = htons(port);

1104

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

767

1105

}

768

1106

769

1107

if(quit_now){

787

1125

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

788

1126

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

789

1127

if(af == AF_INET6){

790

ret = getnameinfo((struct sockaddr *)&(to.in6), sizeof(to.in6),

1128

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

1129

sizeof(struct sockaddr_in6),

791

1130

addrstr, sizeof(addrstr), NULL, 0,

792

1131

NI_NUMERICHOST);

793

1132

} else {

794

ret = getnameinfo((struct sockaddr *)&(to.in), sizeof(to.in),

1133

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

1134

sizeof(struct sockaddr_in),

795

1135

addrstr, sizeof(addrstr), NULL, 0,

796

1136

NI_NUMERICHOST);

797

1137

}

809

1149

goto mandos_end;

810

1150

}

811

1151

812

if(af == AF_INET6){

813

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

814

} else {

815

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

816

}

817

if(ret < 0){

818

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

819

int e = errno;

820

perror_plus("connect");

821

errno = e;

822

}

823

goto mandos_end;

824

}

825

826

if(quit_now){

827

errno = EINTR;

828

goto mandos_end;

1152

while(true){

1153

if(af == AF_INET6){

1154

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

1155

sizeof(struct sockaddr_in6));

1156

} else {

1157

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

1158

sizeof(struct sockaddr_in));

1159

}

1160

if(ret < 0){

1161

if(errno == ENETUNREACH

1162

and if_index != AVAHI_IF_UNSPEC

1163

and connect_to == NULL

1164

and not route_added and

1165

((af == AF_INET6 and not

1166

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1167

&to)->sin6_addr)))

1168

or (af == AF_INET and

1169

/* Not a a IPv4LL address */

1170

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

1171

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

1172

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

1173

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

1174

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

1175

connect to a Mandos server announced by Avahi on a server

1176

host with a global address. Work around this by retrying

1177

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

1178

1179

Avahi bug reference:

1180

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

1181

https://bugs.debian.org/587961

1182

*/

1183

if(debug){

1184

fprintf_plus(stderr, "Mandos server unreachable, trying"

1185

" direct route\n");

1186

}

1187

int e = errno;

1188

route_added = add_local_route(ip, if_index);

1189

if(route_added){

1190

continue;

1191

}

1192

errno = e;

1193

}

1194

if(errno != ECONNREFUSED or debug){

1195

int e = errno;

1196

perror_plus("connect");

1197

errno = e;

1198

}

1199

goto mandos_end;

1200

}

1201

1202

if(quit_now){

1203

errno = EINTR;

1204

goto mandos_end;

1205

}

1206

break;

829

1207

}

830

1208

831

1209

const char *out = mandos_protocol_version;

1014

1392

1015

1393

mandos_end:

1016

1394

{

1395

if(route_added){

1396

if(not delete_local_route(ip, if_index)){

1397

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

1398

" interface %d", ip, if_index);

1399

}

1400

}

1017

1401

int e = errno;

1018

1402

free(decrypted_buffer);

1019

1403

free(buffer);

1036

1420

return retval;

1037

1421

}

1038

1422

1423

__attribute__((nonnull))

1039

1424

static void resolve_callback(AvahiSServiceResolver *r,

1040

1425

AvahiIfIndex interface,

1041

1426

AvahiProtocol proto,

1049

1434

AVAHI_GCC_UNUSED AvahiStringList *txt,

1050

1435

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1051

1436

flags,

1052

void* mc){

1437

void *mc){

1053

1438

if(r == NULL){

1054

1439

return;

1055

1440

}

1058

1443

timed out */

1059

1444

1060

1445

if(quit_now){

1446

avahi_s_service_resolver_free(r);

1061

1447

return;

1062

1448

}

1063

1449

1108

1494

const char *domain,

1109

1495

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1110

1496

flags,

1111

void* mc){

1497

void *mc){

1112

1498

if(b == NULL){

1113

1499

return;

1114

1500

}

1174

1560

errno = old_errno;

1175

1561

}

1176

1562

1563

__attribute__((nonnull, warn_unused_result))

1177

1564

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

1178

1565

int ret;

1179

1566

error_t ret_errno;

1198

1585

return true;

1199

1586

}

1200

1587

1588

__attribute__((nonnull, warn_unused_result))

1201

1589

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

1202

1590

1203

1591

/* Reject the loopback device */

1245

1633

* corresponds to an acceptable network device.

1246

1634

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

1247

1635

*/

1636

__attribute__((nonnull, warn_unused_result))

1248

1637

int good_interface(const struct dirent *if_entry){

1249

1638

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

1250

1639

return 0;

1268

1657

/*

1269

1658

* This function determines if a network interface is up.

1270

1659

*/

1660

__attribute__((nonnull, warn_unused_result))

1271

1661

bool interface_is_up(const char *interface){

1272

1662

struct ifreq ifr;

1273

1663

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

1284

1674

/*

1285

1675

* This function determines if a network interface is running

1286

1676

*/

1677

__attribute__((nonnull, warn_unused_result))

1287

1678

bool interface_is_running(const char *interface){

1288

1679

struct ifreq ifr;

1289

1680

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

1297

1688

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

1298

1689

}

1299

1690

1691

__attribute__((nonnull, pure, warn_unused_result))

1300

1692

int notdotentries(const struct dirent *direntry){

1301

1693

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

1302

1694

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

1309

1701

}

1310

1702

1311

1703

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

1704

__attribute__((nonnull, warn_unused_result))

1312

1705

int runnable_hook(const struct dirent *direntry){

1313

1706

int ret;

1314

1707

size_t sret;

1322

1715

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

1323

1716

"abcdefghijklmnopqrstuvwxyz"

1324

1717

"0123456789"

1325

"_-");

1718

"_.-");

1326

1719

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

1327

1720

/* Contains non-allowed characters */

1328

1721

if(debug){

1332

1725

return 0;

1333

1726

}

1334

1727

1335

char *fullname = NULL;

1336

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

1337

if(ret < 0){

1338

perror_plus("asprintf");

1339

return 0;

1340

}

1341

1342

ret = stat(fullname, &st);

1728

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

1343

1729

if(ret == -1){

1344

1730

if(debug){

1345

1731

perror_plus("Could not stat hook");

1369

1755

return 1;

1370

1756

}

1371

1757

1758

__attribute__((nonnull, warn_unused_result))

1372

1759

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1373

1760

mandos_context *mc){

1374

1761

int ret;

1378

1765

1379

1766

while(true){

1380

1767

if(mc->current_server == NULL){

1381

if (debug){

1768

if(debug){

1382

1769

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

1383

1770

" No timeout!\n");

1384

1771

}

1385

1772

ret = avahi_simple_poll_iterate(s, -1);

1386

1773

} else {

1387

if (debug){

1774

if(debug){

1388

1775

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

1389

1776

" it, or wait\n");

1390

1777

}

1407

1794

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

1408

1795

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

1409

1796

1410

if (debug){

1797

if(debug){

1411

1798

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

1412

1799

block_time);

1413

1800

}

1435

1822

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

1436

1823

}

1437

1824

if(ret != 0){

1438

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

1825

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

1439

1826

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

1440

1827

}

1441

1828

}

1442

1829

}

1443

1830

}

1444

1831

1445

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

1446

error_t raise_privileges(void){

1447

error_t old_errno = errno;

1448

error_t ret_errno = 0;

1449

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

1450

ret_errno = errno;

1451

perror_plus("seteuid");

1452

}

1453

errno = old_errno;

1454

return ret_errno;

1455

}

1456

1457

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

1458

error_t raise_privileges_permanently(void){

1459

error_t old_errno = errno;

1460

error_t ret_errno = raise_privileges();

1461

if(ret_errno != 0){

1462

errno = old_errno;

1463

return ret_errno;

1464

}

1465

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

1466

ret_errno = errno;

1467

perror_plus("seteuid");

1468

}

1469

errno = old_errno;

1470

return ret_errno;

1471

}

1472

1473

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

1474

error_t lower_privileges(void){

1475

error_t old_errno = errno;

1476

error_t ret_errno = 0;

1477

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

1478

ret_errno = errno;

1479

perror_plus("seteuid");

1480

}

1481

errno = old_errno;

1482

return ret_errno;

1483

}

1484

1485

/* Lower privileges permanently */

1486

error_t lower_privileges_permanently(void){

1487

error_t old_errno = errno;

1488

error_t ret_errno = 0;

1489

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

1490

ret_errno = errno;

1491

perror_plus("setuid");

1492

}

1493

errno = old_errno;

1494

return ret_errno;

1495

}

1496

1497

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

1832

__attribute__((nonnull))

1833

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

1498

1834

const float delay){

1499

struct dirent **direntries;

1500

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

1501

alphasort);

1835

struct dirent **direntries = NULL;

1836

if(hookdir_fd == -1){

1837

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1838

| O_CLOEXEC);

1839

if(hookdir_fd == -1){

1840

if(errno == ENOENT){

1841

if(debug){

1842

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

1843

" found\n", hookdir);

1844

}

1845

} else {

1846

perror_plus("open");

1847

}

1848

return;

1849

}

1850

}

1851

#ifdef __GLIBC__

1852

#if __GLIBC_PREREQ(2, 15)

1853

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

1854

runnable_hook, alphasort);

1855

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

1856

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

1857

alphasort);

1858

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

1859

#else /* not __GLIBC__ */

1860

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

1861

alphasort);

1862

#endif /* not __GLIBC__ */

1502

1863

if(numhooks == -1){

1503

if(errno == ENOENT){

1504

if(debug){

1505

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

1506

" found\n", hookdir);

1507

}

1508

} else {

1509

perror_plus("scandir");

1864

perror_plus("scandir");

1865

return;

1866

}

1867

struct dirent *direntry;

1868

int ret;

1869

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

1870

if(devnull == -1){

1871

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

1872

return;

1873

}

1874

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

1875

direntry = direntries[i];

1876

if(debug){

1877

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

1878

direntry->d_name);

1510

1879

}

1511

} else {

1512

struct dirent *direntry;

1513

int ret;

1514

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

1515

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

1516

direntry = direntries[i];

1517

char *fullname = NULL;

1518

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

1519

if(ret < 0){

1880

pid_t hook_pid = fork();

1881

if(hook_pid == 0){

1882

/* Child */

1883

/* Raise privileges */

1884

errno = raise_privileges_permanently();

1885

if(errno != 0){

1886

perror_plus("Failed to raise privileges");

1887

_exit(EX_NOPERM);

1888

}

1889

/* Set group */

1890

errno = 0;

1891

ret = setgid(0);

1892

if(ret == -1){

1893

perror_plus("setgid");

1894

_exit(EX_NOPERM);

1895

}

1896

/* Reset supplementary groups */

1897

errno = 0;

1898

ret = setgroups(0, NULL);

1899

if(ret == -1){

1900

perror_plus("setgroups");

1901

_exit(EX_NOPERM);

1902

}

1903

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

1904

if(ret == -1){

1905

perror_plus("setenv");

1906

_exit(EX_OSERR);

1907

}

1908

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

1909

if(ret == -1){

1910

perror_plus("setenv");

1911

_exit(EX_OSERR);

1912

}

1913

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

1914

if(ret == -1){

1915

perror_plus("setenv");

1916

_exit(EX_OSERR);

1917

}

1918

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

1919

if(ret == -1){

1920

perror_plus("setenv");

1921

_exit(EX_OSERR);

1922

}

1923

char *delaystring;

1924

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

1925

if(ret == -1){

1520

1926

perror_plus("asprintf");

1521

continue;

1522

}

1523

if(debug){

1524

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

1525

direntry->d_name);

1526

}

1527

pid_t hook_pid = fork();

1528

if(hook_pid == 0){

1529

/* Child */

1530

/* Raise privileges */

1531

raise_privileges_permanently();

1532

/* Set group */

1533

errno = 0;

1534

ret = setgid(0);

1535

if(ret == -1){

1536

perror_plus("setgid");

1537

}

1538

/* Reset supplementary groups */

1539

errno = 0;

1540

ret = setgroups(0, NULL);

1541

if(ret == -1){

1542

perror_plus("setgroups");

1543

}

1544

dup2(devnull, STDIN_FILENO);

1545

close(devnull);

1546

dup2(STDERR_FILENO, STDOUT_FILENO);

1547

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

1548

if(ret == -1){

1549

perror_plus("setenv");

1550

_exit(EX_OSERR);

1551

}

1552

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

1553

if(ret == -1){

1554

perror_plus("setenv");

1555

_exit(EX_OSERR);

1556

}

1557

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

1558

if(ret == -1){

1559

perror_plus("setenv");

1560

_exit(EX_OSERR);

1561

}

1562

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

1563

if(ret == -1){

1564

perror_plus("setenv");

1565

_exit(EX_OSERR);

1566

}

1567

char *delaystring;

1568

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

1569

if(ret == -1){

1570

perror_plus("asprintf");

1571

_exit(EX_OSERR);

1572

}

1573

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

1574

if(ret == -1){

1575

free(delaystring);

1576

perror_plus("setenv");

1577

_exit(EX_OSERR);

1578

}

1927

_exit(EX_OSERR);

1928

}

1929

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

1930

if(ret == -1){

1579

1931

free(delaystring);

1580

if(connect_to != NULL){

1581

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

1582

if(ret == -1){

1583

perror_plus("setenv");

1584

_exit(EX_OSERR);

1585

}

1586

}

1587

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

1588

perror_plus("execl");

1589

_exit(EXIT_FAILURE);

1590

}

1932

perror_plus("setenv");

1933

_exit(EX_OSERR);

1934

}

1935

free(delaystring);

1936

if(connect_to != NULL){

1937

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

1938

if(ret == -1){

1939

perror_plus("setenv");

1940

_exit(EX_OSERR);

1941

}

1942

}

1943

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

1944

direntry->d_name,

1945

O_RDONLY));

1946

if(hook_fd == -1){

1947

perror_plus("openat");

1948

_exit(EXIT_FAILURE);

1949

}

1950

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

1951

perror_plus("close");

1952

_exit(EXIT_FAILURE);

1953

}

1954

ret = dup2(devnull, STDIN_FILENO);

1955

if(ret == -1){

1956

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

1957

_exit(EX_OSERR);

1958

}

1959

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

1960

if(ret == -1){

1961

perror_plus("close");

1962

_exit(EX_OSERR);

1963

}

1964

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1965

if(ret == -1){

1966

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

1967

_exit(EX_OSERR);

1968

}

1969

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

1970

environ) == -1){

1971

perror_plus("fexecve");

1972

_exit(EXIT_FAILURE);

1973

}

1974

} else {

1975

if(hook_pid == -1){

1976

perror_plus("fork");

1977

free(direntry);

1978

continue;

1979

}

1980

int status;

1981

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

1982

perror_plus("waitpid");

1983

free(direntry);

1984

continue;

1985

}

1986

if(WIFEXITED(status)){

1987

if(WEXITSTATUS(status) != 0){

1988

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

1989

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

1990

WEXITSTATUS(status));

1991

free(direntry);

1992

continue;

1993

}

1994

} else if(WIFSIGNALED(status)){

1995

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

1996

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

1997

WTERMSIG(status));

1998

free(direntry);

1999

continue;

1591

2000

} else {

1592

int status;

1593

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

1594

perror_plus("waitpid");

1595

free(fullname);

1596

continue;

1597

}

1598

if(WIFEXITED(status)){

1599

if(WEXITSTATUS(status) != 0){

1600

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

1601

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

1602

WEXITSTATUS(status));

1603

free(fullname);

1604

continue;

1605

}

1606

} else if(WIFSIGNALED(status)){

1607

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

1608

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

1609

WTERMSIG(status));

1610

free(fullname);

1611

continue;

1612

} else {

1613

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

1614

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

1615

free(fullname);

1616

continue;

1617

}

1618

}

1619

free(fullname);

1620

if(debug){

1621

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

1622

direntry->d_name);

1623

}

1624

}

1625

close(devnull);

1626

}

1627

return true;

2001

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

2002

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

2003

free(direntry);

2004

continue;

2005

}

2006

}

2007

if(debug){

2008

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

2009

direntry->d_name);

2010

}

2011

free(direntry);

2012

}

2013

free(direntries);

2014

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

2015

perror_plus("close");

2016

} else {

2017

hookdir_fd = -1;

2018

}

2019

close(devnull);

1628

2020

}

1629

2021

2022

__attribute__((nonnull, warn_unused_result))

1630

2023

error_t bring_up_interface(const char *const interface,

1631

2024

const float delay){

1632

int sd = -1;

1633

2025

error_t old_errno = errno;

1634

error_t ret_errno = 0;

1635

int ret, ret_setflags;

2026

int ret;

1636

2027

struct ifreq network;

1637

2028

unsigned int if_index = if_nametoindex(interface);

1638

2029

if(if_index == 0){

1647

2038

}

1648

2039

1649

2040

if(not interface_is_up(interface)){

1650

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

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

1651

2043

ret_errno = errno;

1652

2044

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

1653

2045

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

2046

errno = old_errno;

1654

2047

return ret_errno;

1655

2048

}

1656

network.ifr_flags |= IFF_UP;

2049

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

1657

2050

1658

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1659

if(sd < 0){

2051

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

2052

if(sd == -1){

1660

2053

ret_errno = errno;

1661

2054

perror_plus("socket");

1662

2055

errno = old_errno;

1663

2056

return ret_errno;

1664

2057

}

1665

2058

1666

2059

if(quit_now){

1667

close(sd);

2060

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

2061

if(ret == -1){

2062

perror_plus("close");

2063

}

1668

2064

errno = old_errno;

1669

2065

return EINTR;

1670

2066

}

1674

2070

interface);

1675

2071

}

1676

2072

1677

/* Raise priviliges */

1678

raise_privileges();

2073

/* Raise privileges */

2074

ret_errno = raise_privileges();

2075

if(ret_errno != 0){

2076

errno = ret_errno;

2077

perror_plus("Failed to raise privileges");

2078

}

1679

2079

1680

2080

#ifdef __linux__

1681

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1682

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

1683

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

1684

bool restore_loglevel = true;

1685

if(ret_linux == -1){

1686

restore_loglevel = false;

1687

perror_plus("klogctl");

2081

int ret_linux;

2082

bool restore_loglevel = false;

2083

if(ret_errno == 0){

2084

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2085

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

2086

ret_linux = klogctl(8, NULL, 5);

2087

if(ret_linux == -1){

2088

perror_plus("klogctl");

2089

} else {

2090

restore_loglevel = true;

2091

}

1688

2092

}

1689

2093

#endif /* __linux__ */

1690

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

1691

ret_errno = errno;

2094

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

2095

ioctl_errno = errno;

1692

2096

#ifdef __linux__

1693

2097

if(restore_loglevel){

1694

2098

ret_linux = klogctl(7, NULL, 0);

1698

2102

}

1699

2103

#endif /* __linux__ */

1700

2104

1701

/* Lower privileges */

1702

lower_privileges();

2105

/* If raise_privileges() succeeded above */

2106

if(ret_errno == 0){

2107

/* Lower privileges */

2108

ret_errno = lower_privileges();

2109

if(ret_errno != 0){

2110

errno = ret_errno;

2111

perror_plus("Failed to lower privileges");

2112

}

2113

}

1703

2114

1704

2115

/* Close the socket */

1705

2116

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

1708

2119

}

1709

2120

1710

2121

if(ret_setflags == -1){

1711

errno = ret_errno;

2122

errno = ioctl_errno;

1712

2123

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1713

2124

errno = old_errno;

1714

return ret_errno;

2125

return ioctl_errno;

1715

2126

}

1716

2127

} else if(debug){

1717

2128

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

1735

2146

return 0;

1736

2147

}

1737

2148

2149

__attribute__((nonnull, warn_unused_result))

1738

2150

error_t take_down_interface(const char *const interface){

1739

2151

error_t old_errno = errno;

1740

2152

struct ifreq network;

1745

2157

return ENXIO;

1746

2158

}

1747

2159

if(interface_is_up(interface)){

1748

error_t ret_errno = 0;

2160

error_t ret_errno = 0, ioctl_errno = 0;

1749

2161

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

1750

2162

ret_errno = errno;

1751

2163

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

1752

2164

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

2165

errno = old_errno;

1753

2166

return ret_errno;

1754

2167

}

1755

2168

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

1756

2169

1757

2170

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

1758

if(sd < 0){

2171

if(sd == -1){

1759

2172

ret_errno = errno;

1760

2173

perror_plus("socket");

1761

2174

errno = old_errno;

1767

2180

interface);

1768

2181

}

1769

2182

1770

/* Raise priviliges */

1771

raise_privileges();

2183

/* Raise privileges */

2184

ret_errno = raise_privileges();

2185

if(ret_errno != 0){

2186

errno = ret_errno;

2187

perror_plus("Failed to raise privileges");

2188

}

1772

2189

1773

2190

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

1774

ret_errno = errno;

2191

ioctl_errno = errno;

1775

2192

1776

/* Lower privileges */

1777

lower_privileges();

2193

/* If raise_privileges() succeeded above */

2194

if(ret_errno == 0){

2195

/* Lower privileges */

2196

ret_errno = lower_privileges();

2197

if(ret_errno != 0){

2198

errno = ret_errno;

2199

perror_plus("Failed to lower privileges");

2200

}

2201

}

1778

2202

1779

2203

/* Close the socket */

1780

2204

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

1783

2207

}

1784

2208

1785

2209

if(ret_setflags == -1){

1786

errno = ret_errno;

2210

errno = ioctl_errno;

1787

2211

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1788

2212

errno = old_errno;

1789

return ret_errno;

2213

return ioctl_errno;

1790

2214

}

1791

2215

} else if(debug){

1792

2216

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

1798

2222

}

1799

2223

1800

2224

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

1801

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

2225

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

1802

2226

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

1803

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

2227

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

1804

2228

.interfaces = NULL, .interfaces_size = 0 };

1805

2229

AvahiSServiceBrowser *sb = NULL;

1806

2230

error_t ret_errno;

1810

2234

int exitcode = EXIT_SUCCESS;

1811

2235

char *interfaces_to_take_down = NULL;

1812

2236

size_t interfaces_to_take_down_size = 0;

1813

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

1814

bool tempdir_created = false;

2237

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

2238

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

2239

char *tempdir = NULL;

1815

2240

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1816

2241

const char *seckey = PATHDIR "/" SECKEY;

1817

2242

const char *pubkey = PATHDIR "/" PUBKEY;

1994

2419

goto end;

1995

2420

}

1996

2421

}

1997

2422

1998

2423

{

1999

2424

/* Work around Debian bug #633582:

2000

2425

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

2001

2426

2002

/* Re-raise priviliges */

2003

if(raise_privileges() == 0){

2427

/* Re-raise privileges */

2428

ret_errno = raise_privileges();

2429

if(ret_errno != 0){

2430

errno = ret_errno;

2431

perror_plus("Failed to raise privileges");

2432

} else {

2004

2433

struct stat st;

2005

2434

2006

2435

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

2023

2452

TEMP_FAILURE_RETRY(close(seckey_fd));

2024

2453

}

2025

2454

}

2026

2455

2027

2456

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

2028

2457

int pubkey_fd = open(pubkey, O_RDONLY);

2029

2458

if(pubkey_fd == -1){

2044

2473

TEMP_FAILURE_RETRY(close(pubkey_fd));

2045

2474

}

2046

2475

}

2047

2476

2048

2477

/* Lower privileges */

2049

lower_privileges();

2478

ret_errno = lower_privileges();

2479

if(ret_errno != 0){

2480

errno = ret_errno;

2481

perror_plus("Failed to lower privileges");

2482

}

2050

2483

}

2051

2484

}

2052

2485

2078

2511

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

2079

2512

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

2080

2513

}

2081

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

2082

interfaces_hooks : "", delay)){

2083

goto end;

2084

}

2514

run_network_hooks("start", interfaces_hooks != NULL ?

2515

interfaces_hooks : "", delay);

2085

2516

}

2086

2517

2087

2518

if(not debug){

2165

2596

2166

2597

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

2167

2598

if(mc.interfaces == NULL){

2168

struct dirent **direntries;

2599

struct dirent **direntries = NULL;

2169

2600

/* Look for any good interfaces */

2170

2601

ret = scandir(sys_class_net, &direntries, good_interface,

2171

2602

alphasort);

2177

2608

if(ret_errno != 0){

2178

2609

errno = ret_errno;

2179

2610

perror_plus("argz_add");

2611

free(direntries[i]);

2180

2612

continue;

2181

2613

}

2182

2614

if(debug){

2183

2615

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

2184

2616

direntries[i]->d_name);

2185

2617

}

2618

free(direntries[i]);

2186

2619

}

2187

2620

free(direntries);

2188

2621

} else {

2189

free(direntries);

2622

if(ret == 0){

2623

free(direntries);

2624

}

2190

2625

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

2191

2626

exitcode = EXIT_FAILURE;

2192

2627

goto end;

2215

2650

break;

2216

2651

}

2217

2652

bool interface_was_up = interface_is_up(interface);

2218

ret = bring_up_interface(interface, delay);

2653

errno = bring_up_interface(interface, delay);

2219

2654

if(not interface_was_up){

2220

if(ret != 0){

2221

errno = ret;

2655

if(errno != 0){

2222

2656

perror_plus("Failed to bring up interface");

2223

2657

} else {

2224

ret_errno = argz_add(&interfaces_to_take_down,

2225

&interfaces_to_take_down_size,

2226

interface);

2227

if(ret_errno != 0){

2228

errno = ret_errno;

2658

errno = argz_add(&interfaces_to_take_down,

2659

&interfaces_to_take_down_size,

2660

interface);

2661

if(errno != 0){

2229

2662

perror_plus("argz_add");

2230

2663

}

2231

2664

}

2262

2695

goto end;

2263

2696

}

2264

2697

2265

if(mkdtemp(tempdir) == NULL){

2698

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

2699

tempdir = mkdtemp(run_tempdir);

2700

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

2701

if(debug){

2702

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

2703

run_tempdir, old_tempdir);

2704

}

2705

tempdir = mkdtemp(old_tempdir);

2706

}

2707

if(tempdir == NULL){

2266

2708

perror_plus("mkdtemp");

2267

2709

goto end;

2268

2710

}

2269

tempdir_created = true;

2270

2711

2271

2712

if(quit_now){

2272

2713

goto end;

2347

2788

sleep((unsigned int)retry_interval);

2348

2789

}

2349

2790

2350

if (not quit_now){

2791

if(not quit_now){

2351

2792

exitcode = EXIT_SUCCESS;

2352

2793

}

2353

2794

2408

2849

if(debug){

2409

2850

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

2410

2851

}

2411

2852

2412

2853

ret = avahi_loop_with_timeout(simple_poll,

2413

2854

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

2414

2855

if(debug){

2450

2891

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

2451

2892

while(mc.current_server != NULL){

2452

2893

server *next = mc.current_server->next;

2894

#ifdef __GNUC__

2895

#pragma GCC diagnostic push

2896

#pragma GCC diagnostic ignored "-Wcast-qual"

2897

#endif

2898

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

2899

#ifdef __GNUC__

2900

#pragma GCC diagnostic pop

2901

#endif

2453

2902

free(mc.current_server);

2454

2903

mc.current_server = next;

2455

2904

}

2456

2905

}

2457

2906

2458

/* Re-raise priviliges */

2907

/* Re-raise privileges */

2459

2908

{

2460

raise_privileges();

2461

2462

/* Run network hooks */

2463

run_network_hooks("stop", interfaces_hooks != NULL ?

2464

interfaces_hooks : "", delay);

2465

2466

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

2467

{

2468

char *interface = NULL;

2469

while((interface=argz_next(interfaces_to_take_down,

2470

interfaces_to_take_down_size,

2471

interface))){

2472

ret_errno = take_down_interface(interface);

2473

if(ret_errno != 0){

2474

errno = ret_errno;

2475

perror_plus("Failed to take down interface");

2476

}

2477

}

2478

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

2479

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

2480

" down\n");

2481

}

2482

}

2483

2484

lower_privileges_permanently();

2909

ret_errno = raise_privileges();

2910

if(ret_errno != 0){

2911

errno = ret_errno;

2912

perror_plus("Failed to raise privileges");

2913

} else {

2914

2915

/* Run network hooks */

2916

run_network_hooks("stop", interfaces_hooks != NULL ?

2917

interfaces_hooks : "", delay);

2918

2919

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

2920

{

2921

char *interface = NULL;

2922

while((interface=argz_next(interfaces_to_take_down,

2923

interfaces_to_take_down_size,

2924

interface))){

2925

ret_errno = take_down_interface(interface);

2926

if(ret_errno != 0){

2927

errno = ret_errno;

2928

perror_plus("Failed to take down interface");

2929

}

2930

}

2931

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

2932

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

2933

" down\n");

2934

}

2935

}

2936

}

2937

2938

ret_errno = lower_privileges_permanently();

2939

if(ret_errno != 0){

2940

errno = ret_errno;

2941

perror_plus("Failed to lower privileges permanently");

2942

}

2485

2943

}

2486

2944

2487

2945

free(interfaces_to_take_down);

2488

2946

free(interfaces_hooks);

2489

2947

2490

2948

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

2491

if(tempdir_created){

2949

if(tempdir != NULL){

2492

2950

struct dirent **direntries = NULL;

2493

struct dirent *direntry = NULL;

2494

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

2495

alphasort);

2496

if (numentries > 0){

2497

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

2498

direntry = direntries[i];

2499

char *fullname = NULL;

2500

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

2501

direntry->d_name);

2502

if(ret < 0){

2503

perror_plus("asprintf");

2504

continue;

2505

}

2506

ret = remove(fullname);

2507

if(ret == -1){

2508

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

2509

strerror(errno));

2510

}

2511

free(fullname);

2951

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

2952

| O_NOFOLLOW

2953

| O_DIRECTORY

2954

| O_PATH));

2955

if(tempdir_fd == -1){

2956

perror_plus("open");

2957

} else {

2958

#ifdef __GLIBC__

2959

#if __GLIBC_PREREQ(2, 15)

2960

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

2961

notdotentries, alphasort);

2962

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

2963

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

2964

alphasort);

2965

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

2966

#else /* not __GLIBC__ */

2967

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

2968

alphasort);

2969

#endif /* not __GLIBC__ */

2970

if(numentries >= 0){

2971

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

2972

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

2973

if(ret == -1){

2974

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

2975

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

2976

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

2977

}

2978

free(direntries[i]);

2979

}

2980

2981

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

2982

free(direntries);

2983

if(numentries == -1){

2984

perror_plus("scandir");

2985

}

2986

ret = rmdir(tempdir);

2987

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

2988

perror_plus("rmdir");

2989

}

2512

2990

}

2513

}

2514

2515

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

2516

free(direntries);

2517

if (numentries == -1){

2518

perror_plus("scandir");

2519

}

2520

ret = rmdir(tempdir);

2521

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

2522

perror_plus("rmdir");

2991

TEMP_FAILURE_RETRY(close(tempdir_fd));

2523

2992

}

2524

2993

}

2525

2994