/mandos/trunk : revision 759

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(),

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

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

58

inet_pton(), connect(),

59

getnameinfo() */

60

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

60

61

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

61

62

*/

62

63

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

72

73

*/

73

74

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

74

75

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

75

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

76

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

76

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

77

unlinkat() */

78

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

77

79

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

78

80

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

79

81

argp_state, struct argp,

91

93

argz_delete(), argz_append(),

92

94

argz_stringify(), argz_add(),

93

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

94

98

95

99

#ifdef __linux__

96

100

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

138

142

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

139

143

char *connect_to = NULL;

140

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

141

146

uid_t uid = 65534;

142

147

gid_t gid = 65534;

143

148

161

166

const char *priority;

162

167

gpgme_ctx_t ctx;

163

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

164

171

} mandos_context;

165

172

166

173

/* global so signal handler can reach it*/

178

185

perror(print_text);

179

186

}

180

187

181

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

188

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

182

189

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

183

190

va_list ap;

184

191

va_start (ap, format);

185

192

186

193

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

187

194

program_invocation_short_name));

188

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

195

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

189

196

}

190

197

191

198

/*

193

200

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

194

201

* "buffer_length" is how much is already used.

195

202

*/

203

__attribute__((nonnull, warn_unused_result))

196

204

size_t incbuffer(char **buffer, size_t buffer_length,

197

205

size_t buffer_capacity){

198

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

199

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

200

if(buffer == NULL){

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

213

return 0;

202

214

}

215

*buffer = new_buf;

203

216

buffer_capacity += BUFFER_SIZE;

204

217

}

205

218

return buffer_capacity;

206

219

}

207

220

208

221

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

222

__attribute__((nonnull, warn_unused_result))

209

223

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

210

224

int af, server **current_server){

211

225

int ret;

220

234

.af = af };

221

235

if(new_server->ip == NULL){

222

236

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);

223

252

return false;

224

253

}

225

254

/* Special case of first server */

227

256

new_server->next = new_server;

228

257

new_server->prev = new_server;

229

258

*current_server = new_server;

230

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

231

259

} else {

260

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

232

261

new_server->next = *current_server;

233

262

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

234

263

new_server->prev->next = new_server;

235

264

(*current_server)->prev = new_server;

236

265

}

237

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

238

if(ret == -1){

239

perror_plus("clock_gettime");

240

return false;

241

}

242

266

return true;

243

267

}

244

268

245

269

/*

246

270

* Initialize GPGME.

247

271

*/

248

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

249

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){

250

277

gpgme_error_t rc;

251

278

gpgme_engine_info_t engine_info;

252

279

253

280

/*

254

281

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

255

282

*/

256

bool import_key(const char *filename){

283

bool import_key(const char * const filename){

257

284

int ret;

258

285

int fd;

259

286

gpgme_data_t pgp_data;

340

367

* Decrypt OpenPGP data.

341

368

* Returns -1 on error

342

369

*/

370

__attribute__((nonnull, warn_unused_result))

343

371

static ssize_t pgp_packet_decrypt(const char *cryptotext,

344

372

size_t crypto_size,

345

373

char **plaintext,

465

493

return plaintext_length;

466

494

}

467

495

468

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){

469

505

const char *ret = gnutls_strerror(value);

470

if(ret == NULL)

471

ret = "(unknown)";

472

return ret;

506

return safe_string(ret);

473

507

}

474

508

475

509

/* GnuTLS log function callback */

510

__attribute__((nonnull))

476

511

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

477

512

const char* string){

478

513

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

479

514

}

480

515

516

__attribute__((nonnull, warn_unused_result))

481

517

static int init_gnutls_global(const char *pubkeyfilename,

482

518

const char *seckeyfilename,

483

519

mandos_context *mc){

484

520

int ret;

521

unsigned int uret;

485

522

486

523

if(debug){

487

524

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

538

575

safer_gnutls_strerror(ret));

539

576

goto globalfail;

540

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

}

541

679

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

542

680

if(ret != GNUTLS_E_SUCCESS){

543

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

544

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));

545

683

goto globalfail;

546

684

}

547

685

557

695

return -1;

558

696

}

559

697

698

__attribute__((nonnull, warn_unused_result))

560

699

static int init_gnutls_session(gnutls_session_t *session,

561

700

mandos_context *mc){

562

701

int ret;

618

757

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

619

758

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

620

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

621

977

/* Called when a Mandos server is found */

978

__attribute__((nonnull, warn_unused_result))

622

979

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

623

980

AvahiIfIndex if_index,

624

981

int af, mandos_context *mc){

625

982

int ret, tcp_sd = -1;

626

983

ssize_t sret;

627

union {

628

struct sockaddr_in in;

629

struct sockaddr_in6 in6;

630

} to;

984

struct sockaddr_storage to;

631

985

char *buffer = NULL;

632

986

char *decrypted_buffer = NULL;

633

987

size_t buffer_length = 0;

636

990

int retval = -1;

637

991

gnutls_session_t session;

638

992

int pf; /* Protocol family */

993

bool route_added = false;

639

994

640

995

errno = 0;

641

996

657

1012

return -1;

658

1013

}

659

1014

1015

/* If the interface is specified and we have a list of interfaces */

1016

if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){

1017

/* Check if the interface is one of the interfaces we are using */

1018

bool match = false;

1019

{

1020

char *interface = NULL;

1021

while((interface=argz_next(mc->interfaces, mc->interfaces_size,

1022

interface))){

1023

if(if_nametoindex(interface) == (unsigned int)if_index){

1024

match = true;

1025

break;

1026

}

1027

}

1028

}

1029

if(not match){

1030

/* This interface does not match any in the list, so we don't

1031

connect to the server */

1032

if(debug){

1033

char interface[IF_NAMESIZE];

1034

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

1035

perror_plus("if_indextoname");

1036

} else {

1037

fprintf_plus(stderr, "Skipping server on non-used interface"

1038

" \"%s\"\n",

1039

if_indextoname((unsigned int)if_index,

1040

interface));

1041

}

1042

}

1043

return -1;

1044

}

1045

}

1046

660

1047

ret = init_gnutls_session(&session, mc);

661

1048

if(ret != 0){

662

1049

return -1;

667

1054

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

668

1055

}

669

1056

670

tcp_sd = socket(pf, SOCK_STREAM, 0);

1057

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

671

1058

if(tcp_sd < 0){

672

1059

int e = errno;

673

1060

perror_plus("socket");

682

1069

683

1070

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

684

1071

if(af == AF_INET6){

685

to.in6.sin6_family = (sa_family_t)af;

686

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);

687

1074

} else { /* IPv4 */

688

to.in.sin_family = (sa_family_t)af;

689

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);

690

1077

}

691

1078

if(ret < 0 ){

692

1079

int e = errno;

701

1088

goto mandos_end;

702

1089

}

703

1090

if(af == AF_INET6){

704

to.in6.sin6_port = htons(port);

705

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

706

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

707

-Wunreachable-code*/

1091

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

1092

if(IN6_IS_ADDR_LINKLOCAL

1093

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

708

1094

if(if_index == AVAHI_IF_UNSPEC){

709

1095

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

710

1096

" incomplete without a network interface\n");

712

1098

goto mandos_end;

713

1099

}

714

1100

/* Set the network interface number as scope */

715

to.in6.sin6_scope_id = (uint32_t)if_index;

1101

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

716

1102

}

717

1103

} else {

718

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

719

-Wconversion and

720

-Wunreachable-code */

1104

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

721

1105

}

722

1106

723

1107

if(quit_now){

740

1124

}

741

1125

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

742

1126

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

743

const char *pcret;

744

if(af == AF_INET6){

745

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

746

sizeof(addrstr));

747

} else {

748

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

749

sizeof(addrstr));

750

}

751

if(pcret == NULL){

752

perror_plus("inet_ntop");

753

} else {

754

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

755

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

756

}

757

}

758

}

759

760

if(quit_now){

761

errno = EINTR;

762

goto mandos_end;

763

}

764

765

if(af == AF_INET6){

766

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

767

} else {

768

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

769

}

770

if(ret < 0){

771

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

772

int e = errno;

773

perror_plus("connect");

774

errno = e;

775

}

776

goto mandos_end;

777

}

778

779

if(quit_now){

780

errno = EINTR;

781

goto mandos_end;

1127

if(af == AF_INET6){

1128

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

1129

sizeof(struct sockaddr_in6),

1130

addrstr, sizeof(addrstr), NULL, 0,

1131

NI_NUMERICHOST);

1132

} else {

1133

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

1134

sizeof(struct sockaddr_in),

1135

addrstr, sizeof(addrstr), NULL, 0,

1136

NI_NUMERICHOST);

1137

}

1138

if(ret == EAI_SYSTEM){

1139

perror_plus("getnameinfo");

1140

} else if(ret != 0) {

1141

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

1142

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

1143

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

1144

}

1145

}

1146

1147

if(quit_now){

1148

errno = EINTR;

1149

goto mandos_end;

1150

}

1151

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;

782

1207

}

783

1208

784

1209

const char *out = mandos_protocol_version;

967

1392

968

1393

mandos_end:

969

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

}

970

1401

int e = errno;

971

1402

free(decrypted_buffer);

972

1403

free(buffer);

989

1420

return retval;

990

1421

}

991

1422

1423

__attribute__((nonnull))

992

1424

static void resolve_callback(AvahiSServiceResolver *r,

993

1425

AvahiIfIndex interface,

994

1426

AvahiProtocol proto,

1002

1434

AVAHI_GCC_UNUSED AvahiStringList *txt,

1003

1435

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1004

1436

flags,

1005

void* mc){

1437

void *mc){

1006

1438

if(r == NULL){

1007

1439

return;

1008

1440

}

1011

1443

timed out */

1012

1444

1013

1445

if(quit_now){

1446

avahi_s_service_resolver_free(r);

1014

1447

return;

1015

1448

}

1016

1449

1061

1494

const char *domain,

1062

1495

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1063

1496

flags,

1064

void* mc){

1497

void *mc){

1065

1498

if(b == NULL){

1066

1499

return;

1067

1500

}

1127

1560

errno = old_errno;

1128

1561

}

1129

1562

1563

__attribute__((nonnull, warn_unused_result))

1130

1564

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

1131

1565

int ret;

1132

1566

error_t ret_errno;

1151

1585

return true;

1152

1586

}

1153

1587

1588

__attribute__((nonnull, warn_unused_result))

1154

1589

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

1155

1590

1156

1591

/* Reject the loopback device */

1198

1633

* corresponds to an acceptable network device.

1199

1634

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

1200

1635

*/

1636

__attribute__((nonnull, warn_unused_result))

1201

1637

int good_interface(const struct dirent *if_entry){

1202

1638

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

1203

1639

return 0;

1221

1657

/*

1222

1658

* This function determines if a network interface is up.

1223

1659

*/

1660

__attribute__((nonnull, warn_unused_result))

1224

1661

bool interface_is_up(const char *interface){

1225

1662

struct ifreq ifr;

1226

1663

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

1237

1674

/*

1238

1675

* This function determines if a network interface is running

1239

1676

*/

1677

__attribute__((nonnull, warn_unused_result))

1240

1678

bool interface_is_running(const char *interface){

1241

1679

struct ifreq ifr;

1242

1680

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

1250

1688

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

1251

1689

}

1252

1690

1691

__attribute__((nonnull, pure, warn_unused_result))

1253

1692

int notdotentries(const struct dirent *direntry){

1254

1693

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

1255

1694

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

1262

1701

}

1263

1702

1264

1703

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

1704

__attribute__((nonnull, warn_unused_result))

1265

1705

int runnable_hook(const struct dirent *direntry){

1266

1706

int ret;

1267

1707

size_t sret;

1275

1715

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

1276

1716

"abcdefghijklmnopqrstuvwxyz"

1277

1717

"0123456789"

1278

"_-");

1718

"_.-");

1279

1719

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

1280

1720

/* Contains non-allowed characters */

1281

1721

if(debug){

1285

1725

return 0;

1286

1726

}

1287

1727

1288

char *fullname = NULL;

1289

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

1290

if(ret < 0){

1291

perror_plus("asprintf");

1292

return 0;

1293

}

1294

1295

ret = stat(fullname, &st);

1728

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

1296

1729

if(ret == -1){

1297

1730

if(debug){

1298

1731

perror_plus("Could not stat hook");

1322

1755

return 1;

1323

1756

}

1324

1757

1758

__attribute__((nonnull, warn_unused_result))

1325

1759

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1326

1760

mandos_context *mc){

1327

1761

int ret;

1331

1765

1332

1766

while(true){

1333

1767

if(mc->current_server == NULL){

1334

if (debug){

1768

if(debug){

1335

1769

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

1336

1770

" No timeout!\n");

1337

1771

}

1338

1772

ret = avahi_simple_poll_iterate(s, -1);

1339

1773

} else {

1340

if (debug){

1774

if(debug){

1341

1775

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

1342

1776

" it, or wait\n");

1343

1777

}

1360

1794

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

1361

1795

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

1362

1796

1363

if (debug){

1797

if(debug){

1364

1798

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

1365

1799

block_time);

1366

1800

}

1388

1822

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

1389

1823

}

1390

1824

if(ret != 0){

1391

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

1825

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

1392

1826

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

1393

1827

}

1394

1828

}

1395

1829

}

1396

1830

}

1397

1831

1398

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

1399

error_t raise_privileges(void){

1400

error_t old_errno = errno;

1401

error_t ret_errno = 0;

1402

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

1403

ret_errno = errno;

1404

perror_plus("seteuid");

1405

}

1406

errno = old_errno;

1407

return ret_errno;

1408

}

1409

1410

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

1411

error_t raise_privileges_permanently(void){

1412

error_t old_errno = errno;

1413

error_t ret_errno = raise_privileges();

1414

if(ret_errno != 0){

1415

errno = old_errno;

1416

return ret_errno;

1417

}

1418

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

1419

ret_errno = errno;

1420

perror_plus("seteuid");

1421

}

1422

errno = old_errno;

1423

return ret_errno;

1424

}

1425

1426

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

1427

error_t lower_privileges(void){

1428

error_t old_errno = errno;

1429

error_t ret_errno = 0;

1430

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

1431

ret_errno = errno;

1432

perror_plus("seteuid");

1433

}

1434

errno = old_errno;

1435

return ret_errno;

1436

}

1437

1438

/* Lower privileges permanently */

1439

error_t lower_privileges_permanently(void){

1440

error_t old_errno = errno;

1441

error_t ret_errno = 0;

1442

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

1443

ret_errno = errno;

1444

perror_plus("setuid");

1445

}

1446

errno = old_errno;

1447

return ret_errno;

1448

}

1449

1450

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

1832

__attribute__((nonnull))

1833

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

1451

1834

const float delay){

1452

struct dirent **direntries;

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__ */

1863

if(numhooks == -1){

1864

perror_plus("scandir");

1865

return;

1866

}

1453

1867

struct dirent *direntry;

1454

1868

int ret;

1455

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

1456

alphasort);

1457

if(numhooks == -1){

1458

if(errno == ENOENT){

1459

if(debug){

1460

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

1461

" found\n", hookdir);

1462

}

1463

} else {

1464

perror_plus("scandir");

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);

1465

1879

}

1466

} else {

1467

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

1468

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

1469

direntry = direntries[i];

1470

char *fullname = NULL;

1471

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

1472

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){

1473

1926

perror_plus("asprintf");

1474

continue;

1475

}

1476

if(debug){

1477

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

1478

direntry->d_name);

1479

}

1480

pid_t hook_pid = fork();

1481

if(hook_pid == 0){

1482

/* Child */

1483

/* Raise privileges */

1484

raise_privileges_permanently();

1485

/* Set group */

1486

errno = 0;

1487

ret = setgid(0);

1488

if(ret == -1){

1489

perror_plus("setgid");

1490

}

1491

/* Reset supplementary groups */

1492

errno = 0;

1493

ret = setgroups(0, NULL);

1494

if(ret == -1){

1495

perror_plus("setgroups");

1496

}

1497

dup2(devnull, STDIN_FILENO);

1498

close(devnull);

1499

dup2(STDERR_FILENO, STDOUT_FILENO);

1500

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

1501

if(ret == -1){

1502

perror_plus("setenv");

1503

_exit(EX_OSERR);

1504

}

1505

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

1506

if(ret == -1){

1507

perror_plus("setenv");

1508

_exit(EX_OSERR);

1509

}

1510

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

1511

if(ret == -1){

1512

perror_plus("setenv");

1513

_exit(EX_OSERR);

1514

}

1515

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

1516

if(ret == -1){

1517

perror_plus("setenv");

1518

_exit(EX_OSERR);

1519

}

1520

char *delaystring;

1521

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

1522

if(ret == -1){

1523

perror_plus("asprintf");

1524

_exit(EX_OSERR);

1525

}

1526

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

1527

if(ret == -1){

1528

free(delaystring);

1529

perror_plus("setenv");

1530

_exit(EX_OSERR);

1531

}

1927

_exit(EX_OSERR);

1928

}

1929

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

1930

if(ret == -1){

1532

1931

free(delaystring);

1533

if(connect_to != NULL){

1534

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

1535

if(ret == -1){

1536

perror_plus("setenv");

1537

_exit(EX_OSERR);

1538

}

1539

}

1540

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

1541

perror_plus("execl");

1542

_exit(EXIT_FAILURE);

1543

}

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;

1544

2000

} else {

1545

int status;

1546

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

1547

perror_plus("waitpid");

1548

free(fullname);

1549

continue;

1550

}

1551

if(WIFEXITED(status)){

1552

if(WEXITSTATUS(status) != 0){

1553

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

1554

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

1555

WEXITSTATUS(status));

1556

free(fullname);

1557

continue;

1558

}

1559

} else if(WIFSIGNALED(status)){

1560

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

1561

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

1562

WTERMSIG(status));

1563

free(fullname);

1564

continue;

1565

} else {

1566

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

1567

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

1568

free(fullname);

1569

continue;

1570

}

1571

}

1572

free(fullname);

1573

if(debug){

1574

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

1575

direntry->d_name);

1576

}

1577

}

1578

close(devnull);

1579

}

1580

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);

1581

2020

}

1582

2021

2022

__attribute__((nonnull, warn_unused_result))

1583

2023

error_t bring_up_interface(const char *const interface,

1584

2024

const float delay){

1585

int sd = -1;

1586

2025

error_t old_errno = errno;

1587

error_t ret_errno = 0;

1588

int ret, ret_setflags;

2026

int ret;

1589

2027

struct ifreq network;

1590

2028

unsigned int if_index = if_nametoindex(interface);

1591

2029

if(if_index == 0){

1600

2038

}

1601

2039

1602

2040

if(not interface_is_up(interface)){

1603

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

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

1604

2043

ret_errno = errno;

1605

2044

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

1606

2045

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

2046

errno = old_errno;

1607

2047

return ret_errno;

1608

2048

}

1609

network.ifr_flags |= IFF_UP;

2049

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

1610

2050

1611

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1612

if(sd < 0){

2051

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

2052

if(sd == -1){

1613

2053

ret_errno = errno;

1614

2054

perror_plus("socket");

1615

2055

errno = old_errno;

1616

2056

return ret_errno;

1617

2057

}

1618

2058

1619

2059

if(quit_now){

1620

close(sd);

2060

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

2061

if(ret == -1){

2062

perror_plus("close");

2063

}

1621

2064

errno = old_errno;

1622

2065

return EINTR;

1623

2066

}

1627

2070

interface);

1628

2071

}

1629

2072

1630

/* Raise priviliges */

1631

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

}

1632

2079

1633

2080

#ifdef __linux__

1634

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1635

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

1636

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

1637

bool restore_loglevel = true;

1638

if(ret_linux == -1){

1639

restore_loglevel = false;

1640

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

}

1641

2092

}

1642

2093

#endif /* __linux__ */

1643

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

1644

ret_errno = errno;

2094

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

2095

ioctl_errno = errno;

1645

2096

#ifdef __linux__

1646

2097

if(restore_loglevel){

1647

2098

ret_linux = klogctl(7, NULL, 0);

1651

2102

}

1652

2103

#endif /* __linux__ */

1653

2104

1654

/* Lower privileges */

1655

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

}

1656

2114

1657

2115

/* Close the socket */

1658

2116

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

1661

2119

}

1662

2120

1663

2121

if(ret_setflags == -1){

1664

errno = ret_errno;

2122

errno = ioctl_errno;

1665

2123

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1666

2124

errno = old_errno;

1667

return ret_errno;

2125

return ioctl_errno;

1668

2126

}

1669

2127

} else if(debug){

1670

2128

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

1688

2146

return 0;

1689

2147

}

1690

2148

2149

__attribute__((nonnull, warn_unused_result))

1691

2150

error_t take_down_interface(const char *const interface){

1692

int sd = -1;

1693

2151

error_t old_errno = errno;

1694

error_t ret_errno = 0;

1695

int ret, ret_setflags;

1696

2152

struct ifreq network;

1697

2153

unsigned int if_index = if_nametoindex(interface);

1698

2154

if(if_index == 0){

1701

2157

return ENXIO;

1702

2158

}

1703

2159

if(interface_is_up(interface)){

2160

error_t ret_errno = 0, ioctl_errno = 0;

1704

2161

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

1705

2162

ret_errno = errno;

1706

2163

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

1707

2164

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

2165

errno = old_errno;

1708

2166

return ret_errno;

1709

2167

}

1710

2168

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

1711

2169

1712

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1713

if(sd < 0){

2170

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

2171

if(sd == -1){

1714

2172

ret_errno = errno;

1715

2173

perror_plus("socket");

1716

2174

errno = old_errno;

1722

2180

interface);

1723

2181

}

1724

2182

1725

/* Raise priviliges */

1726

raise_privileges();

1727

1728

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

1729

ret_errno = errno;

1730

1731

/* Lower privileges */

1732

lower_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

}

2189

2190

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

2191

ioctl_errno = errno;

2192

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

}

1733

2202

1734

2203

/* Close the socket */

1735

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

2204

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

1736

2205

if(ret == -1){

1737

2206

perror_plus("close");

1738

2207

}

1739

2208

1740

2209

if(ret_setflags == -1){

1741

errno = ret_errno;

2210

errno = ioctl_errno;

1742

2211

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

1743

2212

errno = old_errno;

1744

return ret_errno;

2213

return ioctl_errno;

1745

2214

}

1746

2215

} else if(debug){

1747

2216

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

1753

2222

}

1754

2223

1755

2224

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

1756

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

2225

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

1757

2226

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

1758

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

2227

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

2228

.interfaces = NULL, .interfaces_size = 0 };

1759

2229

AvahiSServiceBrowser *sb = NULL;

1760

2230

error_t ret_errno;

1761

2231

int ret;

1762

2232

intmax_t tmpmax;

1763

2233

char *tmp;

1764

2234

int exitcode = EXIT_SUCCESS;

1765

char *interfaces = NULL;

1766

size_t interfaces_size = 0;

1767

2235

char *interfaces_to_take_down = NULL;

1768

2236

size_t interfaces_to_take_down_size = 0;

1769

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

1770

bool tempdir_created = false;

2237

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

2238

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

2239

char *tempdir = NULL;

1771

2240

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1772

2241

const char *seckey = PATHDIR "/" SECKEY;

1773

2242

const char *pubkey = PATHDIR "/" PUBKEY;

1774

2243

char *interfaces_hooks = NULL;

1775

size_t interfaces_hooks_size = 0;

1776

2244

1777

2245

bool gnutls_initialized = false;

1778

2246

bool gpgme_initialized = false;

1869

2337

connect_to = arg;

1870

2338

break;

1871

2339

case 'i': /* --interface */

1872

ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,

1873

(int)',');

2340

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

2341

arg, (int)',');

1874

2342

if(ret_errno != 0){

1875

2343

argp_error(state, "%s", strerror(ret_errno));

1876

2344

}

1951

2419

goto end;

1952

2420

}

1953

2421

}

1954

2422

1955

2423

{

1956

2424

/* Work around Debian bug #633582:

1957

2425

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

1958

2426

1959

/* Re-raise priviliges */

1960

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 {

1961

2433

struct stat st;

1962

2434

1963

2435

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

1980

2452

TEMP_FAILURE_RETRY(close(seckey_fd));

1981

2453

}

1982

2454

}

1983

2455

1984

2456

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

1985

2457

int pubkey_fd = open(pubkey, O_RDONLY);

1986

2458

if(pubkey_fd == -1){

2001

2473

TEMP_FAILURE_RETRY(close(pubkey_fd));

2002

2474

}

2003

2475

}

2004

2476

2005

2477

/* Lower privileges */

2006

errno = 0;

2007

ret = seteuid(uid);

2008

if(ret == -1){

2009

perror_plus("seteuid");

2478

ret_errno = lower_privileges();

2479

if(ret_errno != 0){

2480

errno = ret_errno;

2481

perror_plus("Failed to lower privileges");

2010

2482

}

2011

2483

}

2012

2484

}

2013

2485

2014

/* Remove empty interface names */

2486

/* Remove invalid interface names (except "none") */

2015

2487

{

2016

2488

char *interface = NULL;

2017

while((interface = argz_next(interfaces, interfaces_size,

2489

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2018

2490

interface))){

2019

if(if_nametoindex(interface) == 0){

2020

if(interface[0] != '\0' and strcmp(interface, "none") != 0){

2491

if(strcmp(interface, "none") != 0

2492

and if_nametoindex(interface) == 0){

2493

if(interface[0] != '\0'){

2021

2494

fprintf_plus(stderr, "Not using nonexisting interface"

2022

2495

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

2023

2496

}

2024

argz_delete(&interfaces, &interfaces_size, interface);

2497

argz_delete(&mc.interfaces, &mc.interfaces_size, interface);

2025

2498

interface = NULL;

2026

2499

}

2027

2500

}

2029

2502

2030

2503

/* Run network hooks */

2031

2504

{

2032

2033

if(interfaces != NULL){

2034

interfaces_hooks = malloc(interfaces_size);

2505

if(mc.interfaces != NULL){

2506

interfaces_hooks = malloc(mc.interfaces_size);

2035

2507

if(interfaces_hooks == NULL){

2036

2508

perror_plus("malloc");

2037

2509

goto end;

2038

2510

}

2039

memcpy(interfaces_hooks, interfaces, interfaces_size);

2040

interfaces_hooks_size = interfaces_size;

2041

argz_stringify(interfaces_hooks, interfaces_hooks_size,

2042

(int)',');

2043

}

2044

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

2045

interfaces_hooks : "", delay)){

2046

goto end;

2047

}

2511

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

2512

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

2513

}

2514

run_network_hooks("start", interfaces_hooks != NULL ?

2515

interfaces_hooks : "", delay);

2048

2516

}

2049

2517

2050

2518

if(not debug){

2127

2595

}

2128

2596

2129

2597

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

2130

if(interfaces == NULL){

2131

struct dirent **direntries;

2598

if(mc.interfaces == NULL){

2599

struct dirent **direntries = NULL;

2132

2600

/* Look for any good interfaces */

2133

2601

ret = scandir(sys_class_net, &direntries, good_interface,

2134

2602

alphasort);

2135

2603

if(ret >= 1){

2136

2604

/* Add all found interfaces to interfaces list */

2137

2605

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

2138

ret_errno = argz_add(&interfaces, &interfaces_size,

2606

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

2139

2607

direntries[i]->d_name);

2140

2608

if(ret_errno != 0){

2609

errno = ret_errno;

2141

2610

perror_plus("argz_add");

2611

free(direntries[i]);

2142

2612

continue;

2143

2613

}

2144

2614

if(debug){

2145

2615

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

2146

2616

direntries[i]->d_name);

2147

2617

}

2618

free(direntries[i]);

2148

2619

}

2149

2620

free(direntries);

2150

2621

} else {

2151

free(direntries);

2622

if(ret == 0){

2623

free(direntries);

2624

}

2152

2625

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

2153

2626

exitcode = EXIT_FAILURE;

2154

2627

goto end;

2155

2628

}

2156

2629

}

2157

2630

2158

/* If we only got one interface, explicitly use only that one */

2159

if(argz_count(interfaces, interfaces_size) == 1){

2160

if(debug){

2161

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2162

interfaces);

2163

}

2164

if_index = (AvahiIfIndex)if_nametoindex(interfaces);

2165

}

2166

2167

/* Bring up interfaces which are down */

2168

if(not (argz_count(interfaces, interfaces_size) == 1

2169

and strcmp(interfaces, "none") == 0)){

2631

/* Bring up interfaces which are down, and remove any "none"s */

2632

{

2170

2633

char *interface = NULL;

2171

while((interface = argz_next(interfaces, interfaces_size,

2634

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2172

2635

interface))){

2636

/* If interface name is "none", stop bringing up interfaces.

2637

Also remove all instances of "none" from the list */

2638

if(strcmp(interface, "none") == 0){

2639

argz_delete(&mc.interfaces, &mc.interfaces_size,

2640

interface);

2641

interface = NULL;

2642

while((interface = argz_next(mc.interfaces,

2643

mc.interfaces_size, interface))){

2644

if(strcmp(interface, "none") == 0){

2645

argz_delete(&mc.interfaces, &mc.interfaces_size,

2646

interface);

2647

interface = NULL;

2648

}

2649

}

2650

break;

2651

}

2173

2652

bool interface_was_up = interface_is_up(interface);

2174

ret = bring_up_interface(interface, delay);

2653

errno = bring_up_interface(interface, delay);

2175

2654

if(not interface_was_up){

2176

if(ret != 0){

2177

errno = ret;

2655

if(errno != 0){

2178

2656

perror_plus("Failed to bring up interface");

2179

2657

} else {

2180

ret_errno = argz_add(&interfaces_to_take_down,

2181

&interfaces_to_take_down_size,

2182

interface);

2658

errno = argz_add(&interfaces_to_take_down,

2659

&interfaces_to_take_down_size,

2660

interface);

2661

if(errno != 0){

2662

perror_plus("argz_add");

2663

}

2183

2664

}

2184

2665

}

2185

2666

}

2186

free(interfaces);

2187

interfaces = NULL;

2188

interfaces_size = 0;

2189

2667

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

2190

2668

fprintf_plus(stderr, "No interfaces were brought up\n");

2191

2669

}

2192

2670

}

2193

2671

2672

/* If we only got one interface, explicitly use only that one */

2673

if(argz_count(mc.interfaces, mc.interfaces_size) == 1){

2674

if(debug){

2675

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2676

mc.interfaces);

2677

}

2678

if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);

2679

}

2680

2194

2681

if(quit_now){

2195

2682

goto end;

2196

2683

}

2208

2695

goto end;

2209

2696

}

2210

2697

2211

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){

2212

2708

perror_plus("mkdtemp");

2213

2709

goto end;

2214

2710

}

2215

tempdir_created = true;

2216

2711

2217

2712

if(quit_now){

2218

2713

goto end;

2254

2749

exitcode = EX_USAGE;

2255

2750

goto end;

2256

2751

}

2257

2752

2258

2753

if(quit_now){

2259

2754

goto end;

2260

2755

}

2290

2785

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

2291

2786

(int)retry_interval);

2292

2787

}

2293

sleep((int)retry_interval);

2788

sleep((unsigned int)retry_interval);

2294

2789

}

2295

2790

2296

if (not quit_now){

2791

if(not quit_now){

2297

2792

exitcode = EXIT_SUCCESS;

2298

2793

}

2299

2794

2354

2849

if(debug){

2355

2850

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

2356

2851

}

2357

2852

2358

2853

ret = avahi_loop_with_timeout(simple_poll,

2359

2854

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

2360

2855

if(debug){

2369

2864

}

2370

2865

2371

2866

/* Cleanup things */

2867

free(mc.interfaces);

2868

2372

2869

if(sb != NULL)

2373

2870

avahi_s_service_browser_free(sb);

2374

2871

2394

2891

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

2395

2892

while(mc.current_server != NULL){

2396

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

2397

2902

free(mc.current_server);

2398

2903

mc.current_server = next;

2399

2904

}

2400

2905

}

2401

2906

2402

/* Re-raise priviliges */

2907

/* Re-raise privileges */

2403

2908

{

2404

raise_privileges();

2405

2406

/* Run network hooks */

2407

run_network_hooks("stop", interfaces_hooks != NULL ?

2408

interfaces_hooks : "", delay);

2409

2410

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

2411

{

2412

char *interface = NULL;

2413

while((interface=argz_next(interfaces_to_take_down,

2414

interfaces_to_take_down_size,

2415

interface))){

2416

ret_errno = take_down_interface(interface);

2417

if(ret_errno != 0){

2418

errno = ret_errno;

2419

perror_plus("Failed to take down interface");

2420

}

2421

}

2422

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

2423

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

2424

" down\n");

2425

}

2426

}

2427

2428

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

}

2429

2943

}

2430

2944

2431

2945

free(interfaces_to_take_down);

2432

2946

free(interfaces_hooks);

2433

2947

2434

2948

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

2435

if(tempdir_created){

2949

if(tempdir != NULL){

2436

2950

struct dirent **direntries = NULL;

2437

struct dirent *direntry = NULL;

2438

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

2439

alphasort);

2440

if (numentries > 0){

2441

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

2442

direntry = direntries[i];

2443

char *fullname = NULL;

2444

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

2445

direntry->d_name);

2446

if(ret < 0){

2447

perror_plus("asprintf");

2448

continue;

2449

}

2450

ret = remove(fullname);

2451

if(ret == -1){

2452

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

2453

strerror(errno));

2454

}

2455

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

}

2456

2990

}

2457

}

2458

2459

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

2460

free(direntries);

2461

if (numentries == -1){

2462

perror_plus("scandir");

2463

}

2464

ret = rmdir(tempdir);

2465

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

2466

perror_plus("rmdir");

2991

TEMP_FAILURE_RETRY(close(tempdir_fd));

2467

2992

}

2468

2993

}

2469

2994