/mandos/trunk : revision 537

9

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

10

*

11

* Everything else is

12

13

12

13

14

*

15

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

16

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

32

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

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

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

41

42

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

43

stdout, ferror() */

44

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

43

stdout, ferror(), remove() */

44

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

45

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

46

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

47

strtof(), abort() */

55

opendir(), DIR */

56

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

57

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

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inet_pton(), connect(),

59

getnameinfo() */

60

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

58

inet_pton(), connect() */

59

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

61

60

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

62

61

*/

63

62

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

64

63

strtoimax() */

64

#include <assert.h> /* assert() */

65

#include <errno.h> /* perror(), errno,

66

program_invocation_short_name */

67

#include <time.h> /* nanosleep(), time(), sleep() */

73

*/

74

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

75

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

76

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

77

unlinkat() */

78

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

76

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

77

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

79

78

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

80

79

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

81

80

argp_state, struct argp,

89

88

#include <sys/wait.h> /* waitpid(), WIFEXITED(),

90

89

WEXITSTATUS(), WTERMSIG() */

91

90

#include <grp.h> /* setgroups() */

92

#include <argz.h> /* argz_add_sep(), argz_next(),

93

argz_delete(), argz_append(),

94

argz_stringify(), argz_add(),

95

argz_count() */

96

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

97

EAI_SYSTEM, gai_strerror() */

98

91

99

92

#ifdef __linux__

100

93

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

142

135

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

143

136

char *connect_to = NULL;

144

137

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

uid_t uid = 65534;

147

gid_t gid = 65534;

148

138

149

139

/* Doubly linked list that need to be circularly linked when used */

150

140

typedef struct server{

151

141

const char *ip;

152

in_port_t port;

142

uint16_t port;

153

143

AvahiIfIndex if_index;

154

144

int af;

155

145

struct timespec last_seen;

159

149

160

150

/* Used for passing in values through the Avahi callback functions */

161

151

typedef struct {

152

AvahiSimplePoll *simple_poll;

162

153

AvahiServer *server;

163

154

gnutls_certificate_credentials_t cred;

164

155

unsigned int dh_bits;

166

157

const char *priority;

167

158

gpgme_ctx_t ctx;

168

159

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

171

160

} mandos_context;

172

161

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

162

/* global context so signal handler can reach it*/

163

mandos_context mc = { .simple_poll = NULL, .server = NULL,

164

.dh_bits = 1024, .priority = "SECURE256"

165

":!CTYPE-X.509:+CTYPE-OPENPGP",

166

.current_server = NULL };

175

167

176

168

sig_atomic_t quit_now = 0;

177

169

int signal_received = 0;

185

177

perror(print_text);

186

178

}

187

179

188

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

180

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

189

181

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

190

182

va_list ap;

191

183

va_start (ap, format);

192

184

193

185

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

194

186

program_invocation_short_name));

195

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

187

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

196

188

}

197

189

198

190

/*

200

192

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

201

193

* "buffer_length" is how much is already used.

202

194

*/

203

__attribute__((nonnull, warn_unused_result))

204

195

size_t incbuffer(char **buffer, size_t buffer_length,

205

196

size_t buffer_capacity){

206

197

if(buffer_length + BUFFER_SIZE > buffer_capacity){

207

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

208

if(new_buf == NULL){

209

int old_errno = errno;

210

free(*buffer);

211

errno = old_errno;

212

*buffer = NULL;

198

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

199

if(buffer == NULL){

213

200

return 0;

214

201

}

215

*buffer = new_buf;

216

202

buffer_capacity += BUFFER_SIZE;

217

203

}

218

204

return buffer_capacity;

219

205

}

220

206

221

207

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

222

__attribute__((nonnull, warn_unused_result))

223

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

224

int af, server **current_server){

208

bool add_server(const char *ip, uint16_t port, AvahiIfIndex if_index,

209

int af){

225

210

int ret;

226

211

server *new_server = malloc(sizeof(server));

227

212

if(new_server == NULL){

234

219

.af = af };

235

220

if(new_server->ip == NULL){

236

221

perror_plus("strdup");

237

free(new_server);

238

return false;

239

}

240

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

241

if(ret == -1){

242

perror_plus("clock_gettime");

243

#ifdef __GNUC__

244

#pragma GCC diagnostic push

245

#pragma GCC diagnostic ignored "-Wcast-qual"

246

#endif

247

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

248

#ifdef __GNUC__

249

#pragma GCC diagnostic pop

250

#endif

251

free(new_server);

252

222

return false;

253

223

}

254

224

/* Special case of first server */

255

if(*current_server == NULL){

225

if (mc.current_server == NULL){

256

226

new_server->next = new_server;

257

227

new_server->prev = new_server;

258

*current_server = new_server;

228

mc.current_server = new_server;

229

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

259

230

} else {

260

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

261

new_server->next = *current_server;

262

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

231

new_server->next = mc.current_server;

232

new_server->prev = mc.current_server->prev;

263

233

new_server->prev->next = new_server;

264

(*current_server)->prev = new_server;

234

mc.current_server->prev = new_server;

235

}

236

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

237

if(ret == -1){

238

perror_plus("clock_gettime");

239

return false;

265

240

}

266

241

return true;

267

242

}

269

244

/*

270

245

* Initialize GPGME.

271

246

*/

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){

247

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

248

const char *tempdir){

277

249

gpgme_error_t rc;

278

250

gpgme_engine_info_t engine_info;

279

251

252

280

253

/*

281

254

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

282

255

*/

283

bool import_key(const char * const filename){

256

bool import_key(const char *filename){

284

257

int ret;

285

258

int fd;

286

259

gpgme_data_t pgp_data;

298

271

return false;

299

272

}

300

273

301

rc = gpgme_op_import(mc->ctx, pgp_data);

274

rc = gpgme_op_import(mc.ctx, pgp_data);

302

275

if(rc != GPG_ERR_NO_ERROR){

303

276

fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",

304

277

gpgme_strsource(rc), gpgme_strerror(rc));

348

321

}

349

322

350

323

/* Create new GPGME "context" */

351

rc = gpgme_new(&(mc->ctx));

324

rc = gpgme_new(&(mc.ctx));

352

325

if(rc != GPG_ERR_NO_ERROR){

353

326

fprintf_plus(stderr, "Mandos plugin mandos-client: "

354

327

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

367

340

* Decrypt OpenPGP data.

368

341

* Returns -1 on error

369

342

*/

370

__attribute__((nonnull, warn_unused_result))

371

343

static ssize_t pgp_packet_decrypt(const char *cryptotext,

372

344

size_t crypto_size,

373

char **plaintext,

374

mandos_context *mc){

345

char **plaintext){

375

346

gpgme_data_t dh_crypto, dh_plain;

376

347

gpgme_error_t rc;

377

348

ssize_t ret;

403

374

404

375

/* Decrypt data from the cryptotext data buffer to the plaintext

405

376

data buffer */

406

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

377

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

407

378

if(rc != GPG_ERR_NO_ERROR){

408

379

fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",

409

380

gpgme_strsource(rc), gpgme_strerror(rc));

410

381

plaintext_length = -1;

411

382

if(debug){

412

383

gpgme_decrypt_result_t result;

413

result = gpgme_op_decrypt_result(mc->ctx);

384

result = gpgme_op_decrypt_result(mc.ctx);

414

385

if(result == NULL){

415

386

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

416

387

} else {

493

464

return plaintext_length;

494

465

}

495

466

496

__attribute__((warn_unused_result))

497

static const char *safer_gnutls_strerror(int value){

498

const char *ret = gnutls_strerror(value);

467

static const char * safer_gnutls_strerror(int value){

468

const char *ret = gnutls_strerror(value); /* Spurious warning from

469

-Wunreachable-code */

499

470

if(ret == NULL)

500

471

ret = "(unknown)";

501

472

return ret;

502

473

}

503

474

504

475

/* GnuTLS log function callback */

505

__attribute__((nonnull))

506

476

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

507

477

const char* string){

508

478

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

509

479

}

510

480

511

__attribute__((nonnull, warn_unused_result))

512

481

static int init_gnutls_global(const char *pubkeyfilename,

513

const char *seckeyfilename,

514

mandos_context *mc){

482

const char *seckeyfilename){

515

483

int ret;

516

484

517

485

if(debug){

534

502

}

535

503

536

504

/* OpenPGP credentials */

537

ret = gnutls_certificate_allocate_credentials(&mc->cred);

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

538

506

if(ret != GNUTLS_E_SUCCESS){

539

507

fprintf_plus(stderr, "GnuTLS memory error: %s\n",

540

508

safer_gnutls_strerror(ret));

550

518

}

551

519

552

520

ret = gnutls_certificate_set_openpgp_key_file

553

(mc->cred, pubkeyfilename, seckeyfilename,

521

(mc.cred, pubkeyfilename, seckeyfilename,

554

522

GNUTLS_OPENPGP_FMT_BASE64);

555

523

if(ret != GNUTLS_E_SUCCESS){

556

524

fprintf_plus(stderr,

562

530

}

563

531

564

532

/* GnuTLS server initialization */

565

ret = gnutls_dh_params_init(&mc->dh_params);

533

ret = gnutls_dh_params_init(&mc.dh_params);

566

534

if(ret != GNUTLS_E_SUCCESS){

567

535

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

568

536

" initialization: %s\n",

569

537

safer_gnutls_strerror(ret));

570

538

goto globalfail;

571

539

}

572

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

540

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

573

541

if(ret != GNUTLS_E_SUCCESS){

574

542

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

575

543

safer_gnutls_strerror(ret));

576

544

goto globalfail;

577

545

}

578

546

579

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

547

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

580

548

581

549

return 0;

582

550

583

551

globalfail:

584

552

585

gnutls_certificate_free_credentials(mc->cred);

553

gnutls_certificate_free_credentials(mc.cred);

586

554

gnutls_global_deinit();

587

gnutls_dh_params_deinit(mc->dh_params);

555

gnutls_dh_params_deinit(mc.dh_params);

588

556

return -1;

589

557

}

590

558

591

__attribute__((nonnull, warn_unused_result))

592

static int init_gnutls_session(gnutls_session_t *session,

593

mandos_context *mc){

559

static int init_gnutls_session(gnutls_session_t *session){

594

560

int ret;

595

561

/* GnuTLS session creation */

596

562

do {

608

574

{

609

575

const char *err;

610

576

do {

611

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

577

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

612

578

if(quit_now){

613

579

gnutls_deinit(*session);

614

580

return -1;

625

591

626

592

do {

627

593

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

628

mc->cred);

594

mc.cred);

629

595

if(quit_now){

630

596

gnutls_deinit(*session);

631

597

return -1;

641

607

/* ignore client certificate if any. */

642

608

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

643

609

644

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

645

611

646

612

return 0;

647

613

}

650

616

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

651

617

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

652

618

653

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

654

__attribute__((warn_unused_result))

655

error_t raise_privileges(void){

656

error_t old_errno = errno;

657

error_t ret_errno = 0;

658

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

659

ret_errno = errno;

660

}

661

errno = old_errno;

662

return ret_errno;

663

}

664

665

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

666

__attribute__((warn_unused_result))

667

error_t raise_privileges_permanently(void){

668

error_t old_errno = errno;

669

error_t ret_errno = raise_privileges();

670

if(ret_errno != 0){

671

errno = old_errno;

672

return ret_errno;

673

}

674

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

675

ret_errno = errno;

676

}

677

errno = old_errno;

678

return ret_errno;

679

}

680

681

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

682

__attribute__((warn_unused_result))

683

error_t lower_privileges(void){

684

error_t old_errno = errno;

685

error_t ret_errno = 0;

686

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

687

ret_errno = errno;

688

}

689

errno = old_errno;

690

return ret_errno;

691

}

692

693

/* Lower privileges permanently */

694

__attribute__((warn_unused_result))

695

error_t lower_privileges_permanently(void){

696

error_t old_errno = errno;

697

error_t ret_errno = 0;

698

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

699

ret_errno = errno;

700

}

701

errno = old_errno;

702

return ret_errno;

703

}

704

705

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

706

__attribute__((nonnull, warn_unused_result))

707

static bool add_remove_local_route(const bool add,

708

const char *address,

709

AvahiIfIndex if_index){

710

int ret;

711

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

712

char add_arg[] = "add";

713

char delete_arg[] = "delete";

714

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

715

if(pluginhelperdir == NULL){

716

if(debug){

717

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

718

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

719

}

720

return false;

721

}

722

723

char interface[IF_NAMESIZE];

724

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

725

perror_plus("if_indextoname");

726

return false;

727

}

728

729

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

730

if(devnull == -1){

731

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

732

return false;

733

}

734

pid_t pid = fork();

735

if(pid == 0){

736

/* Child */

737

/* Raise privileges */

738

errno = raise_privileges_permanently();

739

if(errno != 0){

740

perror_plus("Failed to raise privileges");

741

/* _exit(EX_NOPERM); */

742

} else {

743

/* Set group */

744

errno = 0;

745

ret = setgid(0);

746

if(ret == -1){

747

perror_plus("setgid");

748

_exit(EX_NOPERM);

749

}

750

/* Reset supplementary groups */

751

errno = 0;

752

ret = setgroups(0, NULL);

753

if(ret == -1){

754

perror_plus("setgroups");

755

_exit(EX_NOPERM);

756

}

757

}

758

ret = dup2(devnull, STDIN_FILENO);

759

if(ret == -1){

760

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

761

_exit(EX_OSERR);

762

}

763

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

764

if(ret == -1){

765

perror_plus("close");

766

_exit(EX_OSERR);

767

}

768

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

769

if(ret == -1){

770

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

771

_exit(EX_OSERR);

772

}

773

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

774

O_RDONLY

775

| O_DIRECTORY

776

| O_PATH

777

| O_CLOEXEC));

778

if(helperdir_fd == -1){

779

perror_plus("open");

780

_exit(EX_UNAVAILABLE);

781

}

782

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

783

helper, O_RDONLY));

784

if(helper_fd == -1){

785

perror_plus("openat");

786

_exit(EX_UNAVAILABLE);

787

}

788

TEMP_FAILURE_RETRY(close(helperdir_fd));

789

#ifdef __GNUC__

790

#pragma GCC diagnostic push

791

#pragma GCC diagnostic ignored "-Wcast-qual"

792

#endif

793

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

794

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

795

interface, NULL }, environ) == -1){

796

#ifdef __GNUC__

797

#pragma GCC diagnostic pop

798

#endif

799

perror_plus("fexecve");

800

_exit(EXIT_FAILURE);

801

}

802

}

803

if(pid == -1){

804

perror_plus("fork");

805

return false;

806

}

807

int status;

808

pid_t pret = -1;

809

errno = 0;

810

do {

811

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

812

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

813

int errno_raising = 0;

814

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

815

errno_raising = errno;

816

perror_plus("Failed to raise privileges in order to"

817

" kill helper program");

818

}

819

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

820

perror_plus("kill");

821

}

822

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

823

perror_plus("Failed to lower privileges after killing"

824

" helper program");

825

}

826

return false;

827

}

828

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

829

if(pret == -1){

830

perror_plus("waitpid");

831

return false;

832

}

833

if(WIFEXITED(status)){

834

if(WEXITSTATUS(status) != 0){

835

fprintf_plus(stderr, "Error: iprouteadddel exited"

836

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

837

return false;

838

}

839

return true;

840

}

841

if(WIFSIGNALED(status)){

842

fprintf_plus(stderr, "Error: iprouteadddel died by"

843

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

844

return false;

845

}

846

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

847

return false;

848

}

849

850

__attribute__((nonnull, warn_unused_result))

851

static bool add_local_route(const char *address,

852

AvahiIfIndex if_index){

853

return add_remove_local_route(true, address, if_index);

854

}

855

856

__attribute__((nonnull, warn_unused_result))

857

static bool remove_local_route(const char *address,

858

AvahiIfIndex if_index){

859

return add_remove_local_route(false, address, if_index);

860

}

861

862

619

/* Called when a Mandos server is found */

863

__attribute__((nonnull, warn_unused_result))

864

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

620

static int start_mandos_communication(const char *ip, uint16_t port,

865

621

AvahiIfIndex if_index,

866

int af, mandos_context *mc){

622

int af){

867

623

int ret, tcp_sd = -1;

868

624

ssize_t sret;

869

struct sockaddr_storage to;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

870

629

char *buffer = NULL;

871

630

char *decrypted_buffer = NULL;

872

631

size_t buffer_length = 0;

875

634

int retval = -1;

876

635

gnutls_session_t session;

877

636

int pf; /* Protocol family */

878

bool route_added = false;

879

637

880

638

errno = 0;

881

639

897

655

return -1;

898

656

}

899

657

900

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

901

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

902

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

903

bool match = false;

904

{

905

char *interface = NULL;

906

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

907

interface))){

908

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

909

match = true;

910

break;

911

}

912

}

913

}

914

if(not match){

915

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

916

connect to the server */

917

if(debug){

918

char interface[IF_NAMESIZE];

919

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

920

perror_plus("if_indextoname");

921

} else {

922

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

923

" \"%s\"\n",

924

if_indextoname((unsigned int)if_index,

925

interface));

926

}

927

}

928

return -1;

929

}

930

}

931

932

ret = init_gnutls_session(&session, mc);

658

ret = init_gnutls_session(&session);

933

659

if(ret != 0){

934

660

return -1;

935

661

}

936

662

937

663

if(debug){

938

664

fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"

939

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

665

PRIu16 "\n", ip, port);

940

666

}

941

667

942

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

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

943

669

if(tcp_sd < 0){

944

670

int e = errno;

945

671

perror_plus("socket");

954

680

955

681

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

956

682

if(af == AF_INET6){

957

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

958

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

683

to.in6.sin6_family = (sa_family_t)af;

684

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

959

685

} else { /* IPv4 */

960

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

961

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

686

to.in.sin_family = (sa_family_t)af;

687

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

962

688

}

963

689

if(ret < 0 ){

964

690

int e = errno;

973

699

goto mandos_end;

974

700

}

975

701

if(af == AF_INET6){

976

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

977

if(IN6_IS_ADDR_LINKLOCAL

978

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

702

to.in6.sin6_port = htons(port); /* Spurious warnings from

703

-Wconversion and

704

-Wunreachable-code */

705

706

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

707

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

708

-Wunreachable-code*/

979

709

if(if_index == AVAHI_IF_UNSPEC){

980

710

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

981

711

" incomplete without a network interface\n");

983

713

goto mandos_end;

984

714

}

985

715

/* Set the network interface number as scope */

986

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

716

to.in6.sin6_scope_id = (uint32_t)if_index;

987

717

}

988

718

} else {

989

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

719

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

720

-Wconversion and

721

-Wunreachable-code */

990

722

}

991

723

992

724

if(quit_now){

1000

732

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

1001

733

perror_plus("if_indextoname");

1002

734

} else {

1003

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX

1004

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

735

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16

736

"\n", ip, interface, port);

1005

737

}

1006

738

} else {

1007

fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",

1008

ip, (uintmax_t)port);

739

fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",

740

ip, port);

1009

741

}

1010

742

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1011

743

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1012

if(af == AF_INET6){

1013

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

1014

sizeof(struct sockaddr_in6),

1015

addrstr, sizeof(addrstr), NULL, 0,

1016

NI_NUMERICHOST);

1017

} else {

1018

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

1019

sizeof(struct sockaddr_in),

1020

addrstr, sizeof(addrstr), NULL, 0,

1021

NI_NUMERICHOST);

1022

}

1023

if(ret == EAI_SYSTEM){

1024

perror_plus("getnameinfo");

1025

} else if(ret != 0) {

1026

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

1027

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

1028

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

1029

}

1030

}

1031

1032

if(quit_now){

1033

errno = EINTR;

1034

goto mandos_end;

1035

}

1036

1037

while(true){

1038

if(af == AF_INET6){

1039

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

1040

sizeof(struct sockaddr_in6));

1041

} else {

1042

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

1043

sizeof(struct sockaddr_in));

1044

}

1045

if(ret < 0){

1046

if(errno == ENETUNREACH

1047

and if_index != AVAHI_IF_UNSPEC

1048

and connect_to == NULL

1049

and not route_added and

1050

((af == AF_INET6 and not

1051

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1052

&to)->sin6_addr)))

1053

or (af == AF_INET and

1054

/* Not a a IPv4LL address */

1055

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

1056

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

1057

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

1058

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

1059

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

1060

connect to a Mandos server announced by Avahi on a server

1061

host with a global address. Work around this by retrying

1062

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

1063

1064

Avahi bug reference:

1065

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

1066

https://bugs.debian.org/587961

1067

*/

1068

int e = errno;

1069

route_added = add_local_route(ip, if_index);

1070

if(route_added){

1071

continue;

1072

}

1073

errno = e;

1074

}

1075

if(errno != ECONNREFUSED or debug){

1076

int e = errno;

1077

perror_plus("connect");

1078

errno = e;

1079

}

1080

goto mandos_end;

1081

}

1082

1083

if(quit_now){

1084

errno = EINTR;

1085

goto mandos_end;

1086

}

1087

break;

744

const char *pcret;

745

if(af == AF_INET6){

746

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

747

sizeof(addrstr));

748

} else {

749

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

750

sizeof(addrstr));

751

}

752

if(pcret == NULL){

753

perror_plus("inet_ntop");

754

} else {

755

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

756

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

757

}

758

}

759

}

760

761

if(quit_now){

762

errno = EINTR;

763

goto mandos_end;

764

}

765

766

if(af == AF_INET6){

767

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

768

} else {

769

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

770

}

771

if(ret < 0){

772

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

773

int e = errno;

774

perror_plus("connect");

775

errno = e;

776

}

777

goto mandos_end;

778

}

779

780

if(quit_now){

781

errno = EINTR;

782

goto mandos_end;

1088

783

}

1089

784

1090

785

const char *out = mandos_protocol_version;

1126

821

goto mandos_end;

1127

822

}

1128

823

1129

/* This casting via intptr_t is to eliminate warning about casting

1130

an int to a pointer type. This is exactly how the GnuTLS Guile

1131

function "set-session-transport-fd!" does it. */

1132

gnutls_transport_set_ptr(session,

1133

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

824

/* Spurious warning from -Wint-to-pointer-cast */

825

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1134

826

1135

827

if(quit_now){

1136

828

errno = EINTR;

1241

933

if(buffer_length > 0){

1242

934

ssize_t decrypted_buffer_size;

1243

935

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1244

&decrypted_buffer, mc);

936

&decrypted_buffer);

1245

937

if(decrypted_buffer_size >= 0){

1246

938

1247

939

written = 0;

1273

965

1274

966

mandos_end:

1275

967

{

1276

if(route_added){

1277

if(not remove_local_route(ip, if_index)){

1278

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

1279

" interface %d", ip, if_index);

1280

}

1281

}

1282

968

int e = errno;

1283

969

free(decrypted_buffer);

1284

970

free(buffer);

1301

987

return retval;

1302

988

}

1303

989

1304

__attribute__((nonnull))

1305

990

static void resolve_callback(AvahiSServiceResolver *r,

1306

991

AvahiIfIndex interface,

1307

992

AvahiProtocol proto,

1315

1000

AVAHI_GCC_UNUSED AvahiStringList *txt,

1316

1001

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1317

1002

flags,

1318

void *mc){

1319

if(r == NULL){

1320

return;

1321

}

1003

AVAHI_GCC_UNUSED void* userdata){

1004

assert(r);

1322

1005

1323

1006

/* Called whenever a service has been resolved successfully or

1324

1007

timed out */

1325

1008

1326

1009

if(quit_now){

1327

avahi_s_service_resolver_free(r);

1328

1010

return;

1329

1011

}

1330

1012

1334

1016

fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "

1335

1017

"'%s' of type '%s' in domain '%s': %s\n", name, type,

1336

1018

domain,

1337

avahi_strerror(avahi_server_errno

1338

(((mandos_context*)mc)->server)));

1019

avahi_strerror(avahi_server_errno(mc.server)));

1339

1020

break;

1340

1021

1341

1022

case AVAHI_RESOLVER_FOUND:

1347

1028

PRIdMAX ") on port %" PRIu16 "\n", name,

1348

1029

host_name, ip, (intmax_t)interface, port);

1349

1030

}

1350

int ret = start_mandos_communication(ip, (in_port_t)port,

1351

interface,

1352

avahi_proto_to_af(proto),

1353

mc);

1031

int ret = start_mandos_communication(ip, port, interface,

1032

avahi_proto_to_af(proto));

1354

1033

if(ret == 0){

1355

avahi_simple_poll_quit(simple_poll);

1034

avahi_simple_poll_quit(mc.simple_poll);

1356

1035

} else {

1357

if(not add_server(ip, (in_port_t)port, interface,

1358

avahi_proto_to_af(proto),

1359

&((mandos_context*)mc)->current_server)){

1036

if(not add_server(ip, port, interface,

1037

avahi_proto_to_af(proto))){

1360

1038

fprintf_plus(stderr, "Failed to add server \"%s\" to server"

1361

1039

" list\n", name);

1362

1040

}

1375

1053

const char *domain,

1376

1054

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1377

1055

flags,

1378

void *mc){

1379

if(b == NULL){

1380

return;

1381

}

1056

AVAHI_GCC_UNUSED void* userdata){

1057

assert(b);

1382

1058

1383

1059

/* Called whenever a new services becomes available on the LAN or

1384

1060

is removed from the LAN */

1392

1068

case AVAHI_BROWSER_FAILURE:

1393

1069

1394

1070

fprintf_plus(stderr, "(Avahi browser) %s\n",

1395

avahi_strerror(avahi_server_errno

1396

(((mandos_context*)mc)->server)));

1397

avahi_simple_poll_quit(simple_poll);

1071

avahi_strerror(avahi_server_errno(mc.server)));

1072

avahi_simple_poll_quit(mc.simple_poll);

1398

1073

return;

1399

1074

1400

1075

case AVAHI_BROWSER_NEW:

1403

1078

the callback function is called the Avahi server will free the

1404

1079

resolver for us. */

1405

1080

1406

if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,

1407

interface, protocol, name, type,

1408

domain, protocol, 0,

1409

resolve_callback, mc) == NULL)

1081

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1082

name, type, domain, protocol, 0,

1083

resolve_callback, NULL) == NULL)

1410

1084

fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"

1411

1085

" %s\n", name,

1412

avahi_strerror(avahi_server_errno

1413

(((mandos_context*)mc)->server)));

1086

avahi_strerror(avahi_server_errno(mc.server)));

1414

1087

break;

1415

1088

1416

1089

case AVAHI_BROWSER_REMOVE:

1435

1108

signal_received = sig;

1436

1109

int old_errno = errno;

1437

1110

/* set main loop to exit */

1438

if(simple_poll != NULL){

1439

avahi_simple_poll_quit(simple_poll);

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1440

1113

}

1441

1114

errno = old_errno;

1442

1115

}

1443

1116

1444

__attribute__((nonnull, warn_unused_result))

1445

1117

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

1446

1118

int ret;

1447

error_t ret_errno;

1448

1119

1449

1120

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

1450

1121

if(s < 0){

1451

ret_errno = errno;

1452

1122

perror_plus("socket");

1453

errno = ret_errno;

1454

1123

return false;

1455

1124

}

1456

1125

strcpy(ifr->ifr_name, ifname);

1457

1126

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1458

1127

if(ret == -1){

1459

1128

if(debug){

1460

ret_errno = errno;

1461

1129

perror_plus("ioctl SIOCGIFFLAGS");

1462

errno = ret_errno;

1463

1130

}

1464

1131

return false;

1465

1132

}

1466

1133

return true;

1467

1134

}

1468

1135

1469

__attribute__((nonnull, warn_unused_result))

1470

1136

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

1471

1137

1472

1138

/* Reject the loopback device */

1514

1180

* corresponds to an acceptable network device.

1515

1181

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

1516

1182

*/

1517

__attribute__((nonnull, warn_unused_result))

1518

1183

int good_interface(const struct dirent *if_entry){

1519

1184

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

1520

1185

return 0;

1536

1201

}

1537

1202

1538

1203

/*

1539

* This function determines if a network interface is up.

1540

*/

1541

__attribute__((nonnull, warn_unused_result))

1542

bool interface_is_up(const char *interface){

1543

struct ifreq ifr;

1544

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

1545

if(debug){

1546

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

1547

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

1548

}

1549

return false;

1550

}

1551

1552

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

1553

}

1554

1555

/*

1556

* This function determines if a network interface is running

1557

*/

1558

__attribute__((nonnull, warn_unused_result))

1559

bool interface_is_running(const char *interface){

1560

struct ifreq ifr;

1561

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

1562

if(debug){

1563

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

1564

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

1565

}

1566

return false;

1567

}

1568

1569

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

1570

}

1571

1572

__attribute__((nonnull, pure, warn_unused_result))

1204

* This function determines if a directory entry in /sys/class/net

1205

* corresponds to an acceptable network device which is up.

1206

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

1207

*/

1208

int up_interface(const struct dirent *if_entry){

1209

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

1210

return 0;

1211

}

1212

1213

struct ifreq ifr;

1214

if(not get_flags(if_entry->d_name, &ifr)){

1215

if(debug){

1216

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

1217

"\"%s\"\n", if_entry->d_name);

1218

}

1219

return 0;

1220

}

1221

1222

/* Reject down interfaces */

1223

if(not (ifr.ifr_flags & IFF_UP)){

1224

if(debug){

1225

fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",

1226

if_entry->d_name);

1227

}

1228

return 0;

1229

}

1230

1231

/* Reject non-running interfaces */

1232

if(not (ifr.ifr_flags & IFF_RUNNING)){

1233

if(debug){

1234

fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",

1235

if_entry->d_name);

1236

}

1237

return 0;

1238

}

1239

1240

if(not good_flags(if_entry->d_name, &ifr)){

1241

return 0;

1242

}

1243

return 1;

1244

}

1245

1573

1246

int notdotentries(const struct dirent *direntry){

1574

1247

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

1575

1248

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

1582

1255

}

1583

1256

1584

1257

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

1585

__attribute__((nonnull, warn_unused_result))

1586

1258

int runnable_hook(const struct dirent *direntry){

1587

1259

int ret;

1588

1260

size_t sret;

1596

1268

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

1597

1269

"abcdefghijklmnopqrstuvwxyz"

1598

1270

"0123456789"

1599

"_.-");

1271

"_-");

1600

1272

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

1601

1273

/* Contains non-allowed characters */

1602

1274

if(debug){

1606

1278

return 0;

1607

1279

}

1608

1280

1609

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

1281

char *fullname = NULL;

1282

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

1283

if(ret < 0){

1284

perror_plus("asprintf");

1285

return 0;

1286

}

1287

1288

ret = stat(fullname, &st);

1610

1289

if(ret == -1){

1611

1290

if(debug){

1612

1291

perror_plus("Could not stat hook");

1636

1315

return 1;

1637

1316

}

1638

1317

1639

__attribute__((nonnull, warn_unused_result))

1640

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1641

mandos_context *mc){

1318

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1642

1319

int ret;

1643

1320

struct timespec now;

1644

1321

struct timespec waited_time;

1645

1322

intmax_t block_time;

1646

1323

1647

1324

while(true){

1648

if(mc->current_server == NULL){

1649

if(debug){

1325

if(mc.current_server == NULL){

1326

if (debug){

1650

1327

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

1651

1328

" No timeout!\n");

1652

1329

}

1653

1330

ret = avahi_simple_poll_iterate(s, -1);

1654

1331

} else {

1655

if(debug){

1332

if (debug){

1656

1333

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

1657

1334

" it, or wait\n");

1658

1335

}

1665

1342

/* Calculating in ms how long time between now and server

1666

1343

who we visted longest time ago. Now - last seen. */

1667

1344

waited_time.tv_sec = (now.tv_sec

1668

- mc->current_server->last_seen.tv_sec);

1345

- mc.current_server->last_seen.tv_sec);

1669

1346

waited_time.tv_nsec = (now.tv_nsec

1670

- mc->current_server->last_seen.tv_nsec);

1347

- mc.current_server->last_seen.tv_nsec);

1671

1348

/* total time is 10s/10,000ms.

1672

1349

Converting to s from ms by dividing by 1,000,

1673

1350

and ns to ms by dividing by 1,000,000. */

1675

1352

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

1676

1353

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

1677

1354

1678

if(debug){

1355

if (debug){

1679

1356

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

1680

1357

block_time);

1681

1358

}

1682

1359

1683

1360

if(block_time <= 0){

1684

ret = start_mandos_communication(mc->current_server->ip,

1685

mc->current_server->port,

1686

mc->current_server->if_index,

1687

mc->current_server->af, mc);

1361

ret = start_mandos_communication(mc.current_server->ip,

1362

mc.current_server->port,

1363

mc.current_server->if_index,

1364

mc.current_server->af);

1688

1365

if(ret == 0){

1689

avahi_simple_poll_quit(s);

1366

avahi_simple_poll_quit(mc.simple_poll);

1690

1367

return 0;

1691

1368

}

1692

1369

ret = clock_gettime(CLOCK_MONOTONIC,

1693

&mc->current_server->last_seen);

1370

&mc.current_server->last_seen);

1694

1371

if(ret == -1){

1695

1372

perror_plus("clock_gettime");

1696

1373

return -1;

1697

1374

}

1698

mc->current_server = mc->current_server->next;

1375

mc.current_server = mc.current_server->next;

1699

1376

block_time = 0; /* Call avahi to find new Mandos

1700

1377

servers, but don't block */

1701

1378

}

1703

1380

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

1704

1381

}

1705

1382

if(ret != 0){

1706

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

1383

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

1707

1384

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

1708

1385

}

1709

1386

}

1710

1387

}

1711

1388

}

1712

1389

1713

__attribute__((nonnull))

1714

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

1390

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

1715

1391

const float delay){

1716

struct dirent **direntries = NULL;

1717

if(hookdir_fd == -1){

1718

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1719

| O_CLOEXEC);

1720

if(hookdir_fd == -1){

1721

if(errno == ENOENT){

1722

if(debug){

1723

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

1724

" found\n", hookdir);

1725

}

1726

} else {

1727

perror_plus("open");

1728

}

1729

return;

1730

}

1731

}

1732

#ifdef __GLIBC__

1733

#if __GLIBC_PREREQ(2, 15)

1734

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

1735

runnable_hook, alphasort);

1736

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

1737

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

1738

alphasort);

1739

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

1740

#else /* not __GLIBC__ */

1741

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

1742

alphasort);

1743

#endif /* not __GLIBC__ */

1392

struct dirent **direntries;

1393

struct dirent *direntry;

1394

int ret;

1395

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

1396

alphasort);

1744

1397

if(numhooks == -1){

1745

1398

perror_plus("scandir");

1746

return;

1747

}

1748

struct dirent *direntry;

1749

int ret;

1750

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

1751

if(devnull == -1){

1752

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

1753

return;

1754

}

1755

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

1756

direntry = direntries[i];

1757

if(debug){

1758

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

1759

direntry->d_name);

1760

}

1761

pid_t hook_pid = fork();

1762

if(hook_pid == 0){

1763

/* Child */

1764

/* Raise privileges */

1765

errno = raise_privileges_permanently();

1766

if(errno != 0){

1767

perror_plus("Failed to raise privileges");

1768

_exit(EX_NOPERM);

1769

}

1770

/* Set group */

1771

errno = 0;

1772

ret = setgid(0);

1773

if(ret == -1){

1774

perror_plus("setgid");

1775

_exit(EX_NOPERM);

1776

}

1777

/* Reset supplementary groups */

1778

errno = 0;

1779

ret = setgroups(0, NULL);

1780

if(ret == -1){

1781

perror_plus("setgroups");

1782

_exit(EX_NOPERM);

1783

}

1784

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

1785

if(ret == -1){

1786

perror_plus("setenv");

1787

_exit(EX_OSERR);

1788

}

1789

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

1790

if(ret == -1){

1791

perror_plus("setenv");

1792

_exit(EX_OSERR);

1793

}

1794

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

1795

if(ret == -1){

1796

perror_plus("setenv");

1797

_exit(EX_OSERR);

1798

}

1799

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

1800

if(ret == -1){

1801

perror_plus("setenv");

1802

_exit(EX_OSERR);

1803

}

1804

char *delaystring;

1805

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

1806

if(ret == -1){

1399

} else {

1400

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

1401

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

1402

direntry = direntries[i];

1403

char *fullname = NULL;

1404

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

1405

if(ret < 0){

1807

1406

perror_plus("asprintf");

1808

_exit(EX_OSERR);

1809

}

1810

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

1811

if(ret == -1){

1407

continue;

1408

}

1409

if(debug){

1410

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

1411

direntry->d_name);

1412

}

1413

pid_t hook_pid = fork();

1414

if(hook_pid == 0){

1415

/* Child */

1416

/* Raise privileges */

1417

errno = 0;

1418

ret = seteuid(0);

1419

if(ret == -1){

1420

perror_plus("seteuid");

1421

}

1422

/* Raise privileges even more */

1423

errno = 0;

1424

ret = setuid(0);

1425

if(ret == -1){

1426

perror_plus("setuid");

1427

}

1428

/* Set group */

1429

errno = 0;

1430

ret = setgid(0);

1431

if(ret == -1){

1432

perror_plus("setgid");

1433

}

1434

/* Reset supplementary groups */

1435

errno = 0;

1436

ret = setgroups(0, NULL);

1437

if(ret == -1){

1438

perror_plus("setgroups");

1439

}

1440

dup2(devnull, STDIN_FILENO);

1441

close(devnull);

1442

dup2(STDERR_FILENO, STDOUT_FILENO);

1443

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

1444

if(ret == -1){

1445

perror_plus("setenv");

1446

_exit(EX_OSERR);

1447

}

1448

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

1449

if(ret == -1){

1450

perror_plus("setenv");

1451

_exit(EX_OSERR);

1452

}

1453

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

1454

if(ret == -1){

1455

perror_plus("setenv");

1456

_exit(EX_OSERR);

1457

}

1458

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

1459

if(ret == -1){

1460

perror_plus("setenv");

1461

_exit(EX_OSERR);

1462

}

1463

char *delaystring;

1464

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

1465

if(ret == -1){

1466

perror_plus("asprintf");

1467

_exit(EX_OSERR);

1468

}

1469

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

1470

if(ret == -1){

1471

free(delaystring);

1472

perror_plus("setenv");

1473

_exit(EX_OSERR);

1474

}

1812

1475

free(delaystring);

1813

perror_plus("setenv");

1814

_exit(EX_OSERR);

1815

}

1816

free(delaystring);

1817

if(connect_to != NULL){

1818

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

1819

if(ret == -1){

1820

perror_plus("setenv");

1821

_exit(EX_OSERR);

1822

}

1823

}

1824

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

1825

direntry->d_name,

1826

O_RDONLY));

1827

if(hook_fd == -1){

1828

perror_plus("openat");

1829

_exit(EXIT_FAILURE);

1830

}

1831

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

1832

perror_plus("close");

1833

_exit(EXIT_FAILURE);

1834

}

1835

ret = dup2(devnull, STDIN_FILENO);

1836

if(ret == -1){

1837

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

1838

_exit(EX_OSERR);

1839

}

1840

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

1841

if(ret == -1){

1842

perror_plus("close");

1843

_exit(EX_OSERR);

1844

}

1845

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

1846

if(ret == -1){

1847

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

1848

_exit(EX_OSERR);

1849

}

1850

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

1851

environ) == -1){

1852

perror_plus("fexecve");

1853

_exit(EXIT_FAILURE);

1854

}

1855

} else {

1856

if(hook_pid == -1){

1857

perror_plus("fork");

1858

free(direntry);

1859

continue;

1860

}

1861

int status;

1862

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

1863

perror_plus("waitpid");

1864

free(direntry);

1865

continue;

1866

}

1867

if(WIFEXITED(status)){

1868

if(WEXITSTATUS(status) != 0){

1869

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

1870

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

1871

WEXITSTATUS(status));

1872

free(direntry);

1873

continue;

1874

}

1875

} else if(WIFSIGNALED(status)){

1876

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

1877

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

1878

WTERMSIG(status));

1879

free(direntry);

1880

continue;

1881

} else {

1882

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

1883

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

1884

free(direntry);

1885

continue;

1886

}

1887

}

1888

if(debug){

1889

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

1890

direntry->d_name);

1891

}

1892

free(direntry);

1893

}

1894

free(direntries);

1895

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

1896

perror_plus("close");

1897

} else {

1898

hookdir_fd = -1;

1899

}

1900

close(devnull);

1901

}

1902

1903

__attribute__((nonnull, warn_unused_result))

1904

error_t bring_up_interface(const char *const interface,

1905

const float delay){

1906

error_t old_errno = errno;

1907

int ret;

1908

struct ifreq network;

1909

unsigned int if_index = if_nametoindex(interface);

1910

if(if_index == 0){

1911

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1912

errno = old_errno;

1913

return ENXIO;

1914

}

1915

1916

if(quit_now){

1917

errno = old_errno;

1918

return EINTR;

1919

}

1920

1921

if(not interface_is_up(interface)){

1922

error_t ret_errno = 0, ioctl_errno = 0;

1923

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

1924

ret_errno = errno;

1925

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

1926

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

1927

errno = old_errno;

1928

return ret_errno;

1929

}

1930

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

1931

1932

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

1933

if(sd == -1){

1934

ret_errno = errno;

1935

perror_plus("socket");

1936

errno = old_errno;

1937

return ret_errno;

1938

}

1939

1940

if(quit_now){

1941

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

1942

if(ret == -1){

1943

perror_plus("close");

1944

}

1945

errno = old_errno;

1946

return EINTR;

1947

}

1948

1949

if(debug){

1950

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

1951

interface);

1952

}

1953

1954

/* Raise privileges */

1955

ret_errno = raise_privileges();

1956

if(ret_errno != 0){

1957

errno = ret_errno;

1958

perror_plus("Failed to raise privileges");

1959

}

1960

1961

#ifdef __linux__

1962

int ret_linux;

1963

bool restore_loglevel = false;

1964

if(ret_errno == 0){

1965

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1966

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

1967

ret_linux = klogctl(8, NULL, 5);

1968

if(ret_linux == -1){

1969

perror_plus("klogctl");

1970

} else {

1971

restore_loglevel = true;

1972

}

1973

}

1974

#endif /* __linux__ */

1975

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

1976

ioctl_errno = errno;

1977

#ifdef __linux__

1978

if(restore_loglevel){

1979

ret_linux = klogctl(7, NULL, 0);

1980

if(ret_linux == -1){

1981

perror_plus("klogctl");

1982

}

1983

}

1984

#endif /* __linux__ */

1985

1986

/* If raise_privileges() succeeded above */

1987

if(ret_errno == 0){

1988

/* Lower privileges */

1989

ret_errno = lower_privileges();

1990

if(ret_errno != 0){

1991

errno = ret_errno;

1992

perror_plus("Failed to lower privileges");

1993

}

1994

}

1995

1996

/* Close the socket */

1997

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

1998

if(ret == -1){

1999

perror_plus("close");

2000

}

2001

2002

if(ret_setflags == -1){

2003

errno = ioctl_errno;

2004

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2005

errno = old_errno;

2006

return ioctl_errno;

2007

}

2008

} else if(debug){

2009

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

2010

interface);

2011

}

2012

2013

/* Sleep checking until interface is running.

2014

Check every 0.25s, up to total time of delay */

2015

for(int i=0; i < delay * 4; i++){

2016

if(interface_is_running(interface)){

2017

break;

2018

}

2019

struct timespec sleeptime = { .tv_nsec = 250000000 };

2020

ret = nanosleep(&sleeptime, NULL);

2021

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

2022

perror_plus("nanosleep");

2023

}

2024

}

2025

2026

errno = old_errno;

2027

return 0;

2028

}

2029

2030

__attribute__((nonnull, warn_unused_result))

2031

error_t take_down_interface(const char *const interface){

2032

error_t old_errno = errno;

2033

struct ifreq network;

2034

unsigned int if_index = if_nametoindex(interface);

2035

if(if_index == 0){

2036

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2037

errno = old_errno;

2038

return ENXIO;

2039

}

2040

if(interface_is_up(interface)){

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

2043

ret_errno = errno;

2044

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

2045

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

2046

errno = old_errno;

2047

return ret_errno;

2048

}

2049

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

2050

2051

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

2052

if(sd == -1){

2053

ret_errno = errno;

2054

perror_plus("socket");

2055

errno = old_errno;

2056

return ret_errno;

2057

}

2058

2059

if(debug){

2060

fprintf_plus(stderr, "Taking down interface \"%s\"\n",

2061

interface);

2062

}

2063

2064

/* Raise privileges */

2065

ret_errno = raise_privileges();

2066

if(ret_errno != 0){

2067

errno = ret_errno;

2068

perror_plus("Failed to raise privileges");

2069

}

2070

2071

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

2072

ioctl_errno = errno;

2073

2074

/* If raise_privileges() succeeded above */

2075

if(ret_errno == 0){

2076

/* Lower privileges */

2077

ret_errno = lower_privileges();

2078

if(ret_errno != 0){

2079

errno = ret_errno;

2080

perror_plus("Failed to lower privileges");

2081

}

2082

}

2083

2084

/* Close the socket */

2085

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

2086

if(ret == -1){

2087

perror_plus("close");

2088

}

2089

2090

if(ret_setflags == -1){

2091

errno = ioctl_errno;

2092

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2093

errno = old_errno;

2094

return ioctl_errno;

2095

}

2096

} else if(debug){

2097

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

2098

interface);

2099

}

2100

2101

errno = old_errno;

2102

return 0;

1476

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

1477

perror_plus("execl");

1478

_exit(EXIT_FAILURE);

1479

}

1480

} else {

1481

int status;

1482

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

1483

perror_plus("waitpid");

1484

free(fullname);

1485

continue;

1486

}

1487

if(WIFEXITED(status)){

1488

if(WEXITSTATUS(status) != 0){

1489

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

1490

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

1491

WEXITSTATUS(status));

1492

free(fullname);

1493

continue;

1494

}

1495

} else if(WIFSIGNALED(status)){

1496

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

1497

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

1498

WTERMSIG(status));

1499

free(fullname);

1500

continue;

1501

} else {

1502

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

1503

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

1504

free(fullname);

1505

continue;

1506

}

1507

}

1508

free(fullname);

1509

if(debug){

1510

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

1511

direntry->d_name);

1512

}

1513

}

1514

close(devnull);

1515

}

1516

return true;

2103

1517

}

2104

1518

2105

1519

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

2106

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

2107

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

2108

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

2109

.interfaces = NULL, .interfaces_size = 0 };

2110

1520

AvahiSServiceBrowser *sb = NULL;

2111

error_t ret_errno;

1521

int error;

2112

1522

int ret;

2113

1523

intmax_t tmpmax;

2114

1524

char *tmp;

2115

1525

int exitcode = EXIT_SUCCESS;

2116

char *interfaces_to_take_down = NULL;

2117

size_t interfaces_to_take_down_size = 0;

2118

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

2119

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

2120

char *tempdir = NULL;

1526

const char *interface = "";

1527

struct ifreq network;

1528

int sd = -1;

1529

bool take_down_interface = false;

1530

uid_t uid;

1531

gid_t gid;

1532

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

1533

bool tempdir_created = false;

2121

1534

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2122

1535

const char *seckey = PATHDIR "/" SECKEY;

2123

1536

const char *pubkey = PATHDIR "/" PUBKEY;

2124

char *interfaces_hooks = NULL;

2125

1537

2126

1538

bool gnutls_initialized = false;

2127

1539

bool gpgme_initialized = false;

2189

1601

.group = 2 },

2190

1602

{ .name = "retry", .key = 132,

2191

1603

.arg = "SECONDS",

2192

.doc = "Retry interval used when denied by the Mandos server",

1604

.doc = "Retry interval used when denied by the mandos server",

2193

1605

.group = 2 },

2194

1606

{ .name = "network-hook-dir", .key = 133,

2195

1607

.arg = "DIR",

2218

1630

connect_to = arg;

2219

1631

break;

2220

1632

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

2221

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

2222

arg, (int)',');

2223

if(ret_errno != 0){

2224

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

2225

}

1633

interface = arg;

2226

1634

break;

2227

1635

case 's': /* --seckey */

2228

1636

seckey = arg;

2300

1708

goto end;

2301

1709

}

2302

1710

}

2303

1711

2304

1712

{

2305

1713

/* Work around Debian bug #633582:

2306

1714

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

2307

1715

2308

/* Re-raise privileges */

2309

ret_errno = raise_privileges();

2310

if(ret_errno != 0){

2311

errno = ret_errno;

2312

perror_plus("Failed to raise privileges");

1716

/* Re-raise priviliges */

1717

errno = 0;

1718

ret = seteuid(0);

1719

if(ret == -1){

1720

perror_plus("seteuid");

2313

1721

} else {

2314

1722

struct stat st;

2315

1723

2333

1741

TEMP_FAILURE_RETRY(close(seckey_fd));

2334

1742

}

2335

1743

}

2336

1744

2337

1745

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

2338

1746

int pubkey_fd = open(pubkey, O_RDONLY);

2339

1747

if(pubkey_fd == -1){

2354

1762

TEMP_FAILURE_RETRY(close(pubkey_fd));

2355

1763

}

2356

1764

}

2357

1765

2358

1766

/* Lower privileges */

2359

ret_errno = lower_privileges();

2360

if(ret_errno != 0){

2361

errno = ret_errno;

2362

perror_plus("Failed to lower privileges");

2363

}

2364

}

2365

}

2366

2367

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

2368

{

2369

char *interface = NULL;

2370

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

2371

interface))){

2372

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

2373

and if_nametoindex(interface) == 0){

2374

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

2375

fprintf_plus(stderr, "Not using nonexisting interface"

2376

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

2377

}

2378

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

2379

interface = NULL;

1767

errno = 0;

1768

ret = seteuid(uid);

1769

if(ret == -1){

1770

perror_plus("seteuid");

2380

1771

}

2381

1772

}

2382

1773

}

2383

1774

2384

1775

/* Run network hooks */

2385

{

2386

if(mc.interfaces != NULL){

2387

interfaces_hooks = malloc(mc.interfaces_size);

2388

if(interfaces_hooks == NULL){

2389

perror_plus("malloc");

2390

goto end;

2391

}

2392

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

2393

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

2394

}

2395

run_network_hooks("start", interfaces_hooks != NULL ?

2396

interfaces_hooks : "", delay);

1776

if(not run_network_hooks("start", interface, delay)){

1777

goto end;

2397

1778

}

2398

1779

2399

1780

if(not debug){

2400

1781

avahi_set_log_function(empty_log);

2401

1782

}

2402

1783

1784

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

1785

struct dirent **direntries;

1786

/* First look for interfaces that are up */

1787

ret = scandir(sys_class_net, &direntries, up_interface,

1788

alphasort);

1789

if(ret == 0){

1790

/* No up interfaces, look for any good interfaces */

1791

free(direntries);

1792

ret = scandir(sys_class_net, &direntries, good_interface,

1793

alphasort);

1794

}

1795

if(ret >= 1){

1796

/* Pick the first interface returned */

1797

interface = strdup(direntries[0]->d_name);

1798

if(debug){

1799

fprintf_plus(stderr, "Using interface \"%s\"\n", interface);

1800

}

1801

if(interface == NULL){

1802

perror_plus("malloc");

1803

free(direntries);

1804

exitcode = EXIT_FAILURE;

1805

goto end;

1806

}

1807

free(direntries);

1808

} else {

1809

free(direntries);

1810

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

1811

exitcode = EXIT_FAILURE;

1812

goto end;

1813

}

1814

}

1815

2403

1816

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

2404

1817

from the signal handler */

2405

1818

/* Initialize the pseudo-RNG for Avahi */

2406

1819

srand((unsigned int) time(NULL));

2407

simple_poll = avahi_simple_poll_new();

2408

if(simple_poll == NULL){

1820

mc.simple_poll = avahi_simple_poll_new();

1821

if(mc.simple_poll == NULL){

2409

1822

fprintf_plus(stderr,

2410

1823

"Avahi: Failed to create simple poll object.\n");

2411

1824

exitcode = EX_UNAVAILABLE;

2475

1888

}

2476

1889

}

2477

1890

2478

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

2479

if(mc.interfaces == NULL){

2480

struct dirent **direntries = NULL;

2481

/* Look for any good interfaces */

2482

ret = scandir(sys_class_net, &direntries, good_interface,

2483

alphasort);

2484

if(ret >= 1){

2485

/* Add all found interfaces to interfaces list */

2486

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

2487

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

2488

direntries[i]->d_name);

2489

if(ret_errno != 0){

2490

errno = ret_errno;

2491

perror_plus("argz_add");

2492

free(direntries[i]);

2493

continue;

2494

}

2495

if(debug){

2496

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

2497

direntries[i]->d_name);

2498

}

2499

free(direntries[i]);

2500

}

2501

free(direntries);

2502

} else {

2503

if(ret == 0){

2504

free(direntries);

2505

}

2506

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

2507

exitcode = EXIT_FAILURE;

2508

goto end;

2509

}

2510

}

2511

2512

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

2513

{

2514

char *interface = NULL;

2515

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

2516

interface))){

2517

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

2518

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

2519

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

2520

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

2521

interface);

2522

interface = NULL;

2523

while((interface = argz_next(mc.interfaces,

2524

mc.interfaces_size, interface))){

2525

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

2526

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

2527

interface);

2528

interface = NULL;

1891

/* If the interface is down, bring it up */

1892

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

1893

if_index = (AvahiIfIndex) if_nametoindex(interface);

1894

if(if_index == 0){

1895

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1896

exitcode = EX_UNAVAILABLE;

1897

goto end;

1898

}

1899

1900

if(quit_now){

1901

goto end;

1902

}

1903

1904

/* Re-raise priviliges */

1905

errno = 0;

1906

ret = seteuid(0);

1907

if(ret == -1){

1908

perror_plus("seteuid");

1909

}

1910

1911

#ifdef __linux__

1912

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1913

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

1914

ret = klogctl(8, NULL, 5);

1915

bool restore_loglevel = true;

1916

if(ret == -1){

1917

restore_loglevel = false;

1918

perror_plus("klogctl");

1919

}

1920

#endif /* __linux__ */

1921

1922

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1923

if(sd < 0){

1924

perror_plus("socket");

1925

exitcode = EX_OSERR;

1926

#ifdef __linux__

1927

if(restore_loglevel){

1928

ret = klogctl(7, NULL, 0);

1929

if(ret == -1){

1930

perror_plus("klogctl");

1931

}

1932

}

1933

#endif /* __linux__ */

1934

/* Lower privileges */

1935

errno = 0;

1936

ret = seteuid(uid);

1937

if(ret == -1){

1938

perror_plus("seteuid");

1939

}

1940

goto end;

1941

}

1942

strcpy(network.ifr_name, interface);

1943

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1944

if(ret == -1){

1945

perror_plus("ioctl SIOCGIFFLAGS");

1946

#ifdef __linux__

1947

if(restore_loglevel){

1948

ret = klogctl(7, NULL, 0);

1949

if(ret == -1){

1950

perror_plus("klogctl");

1951

}

1952

}

1953

#endif /* __linux__ */

1954

exitcode = EX_OSERR;

1955

/* Lower privileges */

1956

errno = 0;

1957

ret = seteuid(uid);

1958

if(ret == -1){

1959

perror_plus("seteuid");

1960

}

1961

goto end;

1962

}

1963

if((network.ifr_flags & IFF_UP) == 0){

1964

network.ifr_flags |= IFF_UP;

1965

take_down_interface = true;

1966

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

1967

if(ret == -1){

1968

take_down_interface = false;

1969

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1970

exitcode = EX_OSERR;

1971

#ifdef __linux__

1972

if(restore_loglevel){

1973

ret = klogctl(7, NULL, 0);

1974

if(ret == -1){

1975

perror_plus("klogctl");

2529

1976

}

2530

1977

}

1978

#endif /* __linux__ */

1979

/* Lower privileges */

1980

errno = 0;

1981

ret = seteuid(uid);

1982

if(ret == -1){

1983

perror_plus("seteuid");

1984

}

1985

goto end;

1986

}

1987

}

1988

/* Sleep checking until interface is running.

1989

Check every 0.25s, up to total time of delay */

1990

for(int i=0; i < delay * 4; i++){

1991

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1992

if(ret == -1){

1993

perror_plus("ioctl SIOCGIFFLAGS");

1994

} else if(network.ifr_flags & IFF_RUNNING){

2531

1995

break;

2532

1996

}

2533

bool interface_was_up = interface_is_up(interface);

2534

errno = bring_up_interface(interface, delay);

2535

if(not interface_was_up){

2536

if(errno != 0){

2537

perror_plus("Failed to bring up interface");

2538

} else {

2539

errno = argz_add(&interfaces_to_take_down,

2540

&interfaces_to_take_down_size,

2541

interface);

2542

if(errno != 0){

2543

perror_plus("argz_add");

2544

}

2545

}

2546

}

2547

}

2548

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

2549

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

2550

}

2551

}

2552

2553

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

2554

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

2555

if(debug){

2556

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

2557

mc.interfaces);

2558

}

2559

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

1997

struct timespec sleeptime = { .tv_nsec = 250000000 };

1998

ret = nanosleep(&sleeptime, NULL);

1999

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

2000

perror_plus("nanosleep");

2001

}

2002

}

2003

if(not take_down_interface){

2004

/* We won't need the socket anymore */

2005

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

2006

if(ret == -1){

2007

perror_plus("close");

2008

}

2009

}

2010

#ifdef __linux__

2011

if(restore_loglevel){

2012

/* Restores kernel loglevel to default */

2013

ret = klogctl(7, NULL, 0);

2014

if(ret == -1){

2015

perror_plus("klogctl");

2016

}

2017

}

2018

#endif /* __linux__ */

2019

/* Lower privileges */

2020

errno = 0;

2021

/* Lower privileges */

2022

ret = seteuid(uid);

2023

if(ret == -1){

2024

perror_plus("seteuid");

2025

}

2560

2026

}

2561

2027

2562

2028

if(quit_now){

2563

2029

goto end;

2564

2030

}

2565

2031

2566

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

2032

ret = init_gnutls_global(pubkey, seckey);

2567

2033

if(ret == -1){

2568

2034

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

2569

2035

exitcode = EX_UNAVAILABLE;

2576

2042

goto end;

2577

2043

}

2578

2044

2579

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

2580

tempdir = mkdtemp(run_tempdir);

2581

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

2582

if(debug){

2583

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

2584

run_tempdir, old_tempdir);

2585

}

2586

tempdir = mkdtemp(old_tempdir);

2587

}

2588

if(tempdir == NULL){

2045

if(mkdtemp(tempdir) == NULL){

2589

2046

perror_plus("mkdtemp");

2590

2047

goto end;

2591

2048

}

2049

tempdir_created = true;

2592

2050

2593

2051

if(quit_now){

2594

2052

goto end;

2595

2053

}

2596

2054

2597

if(not init_gpgme(pubkey, seckey, tempdir, &mc)){

2055

if(not init_gpgme(pubkey, seckey, tempdir)){

2598

2056

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

2599

2057

exitcode = EX_UNAVAILABLE;

2600

2058

goto end;

2610

2068

/* Connect directly, do not use Zeroconf */

2611

2069

/* (Mainly meant for debugging) */

2612

2070

char *address = strrchr(connect_to, ':');

2613

2614

2071

if(address == NULL){

2615

2072

fprintf_plus(stderr, "No colon in address\n");

2616

2073

exitcode = EX_USAGE;

2621

2078

goto end;

2622

2079

}

2623

2080

2624

in_port_t port;

2081

uint16_t port;

2625

2082

errno = 0;

2626

2083

tmpmax = strtoimax(address+1, &tmp, 10);

2627

2084

if(errno != 0 or tmp == address+1 or *tmp != '\0'

2628

or tmpmax != (in_port_t)tmpmax){

2085

or tmpmax != (uint16_t)tmpmax){

2629

2086

fprintf_plus(stderr, "Bad port number\n");

2630

2087

exitcode = EX_USAGE;

2631

2088

goto end;

2632

2089

}

2633

2090

2634

2091

if(quit_now){

2635

2092

goto end;

2636

2093

}

2637

2094

2638

port = (in_port_t)tmpmax;

2095

port = (uint16_t)tmpmax;

2639

2096

*address = '\0';

2640

2097

/* Colon in address indicates IPv6 */

2641

2098

int af;

2657

2114

}

2658

2115

2659

2116

while(not quit_now){

2660

ret = start_mandos_communication(address, port, if_index, af,

2661

&mc);

2117

ret = start_mandos_communication(address, port, if_index, af);

2662

2118

if(quit_now or ret == 0){

2663

2119

break;

2664

2120

}

2666

2122

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

2667

2123

(int)retry_interval);

2668

2124

}

2669

sleep((unsigned int)retry_interval);

2125

sleep((int)retry_interval);

2670

2126

}

2671

2127

2672

if(not quit_now){

2128

if (not quit_now){

2673

2129

exitcode = EXIT_SUCCESS;

2674

2130

}

2675

2131

2690

2146

config.publish_domain = 0;

2691

2147

2692

2148

/* Allocate a new server */

2693

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2694

&config, NULL, NULL, &ret_errno);

2149

mc.server = avahi_server_new(avahi_simple_poll_get

2150

(mc.simple_poll), &config, NULL,

2151

NULL, &error);

2695

2152

2696

2153

/* Free the Avahi configuration data */

2697

2154

avahi_server_config_free(&config);

2700

2157

/* Check if creating the Avahi server object succeeded */

2701

2158

if(mc.server == NULL){

2702

2159

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2703

avahi_strerror(ret_errno));

2160

avahi_strerror(error));

2704

2161

exitcode = EX_UNAVAILABLE;

2705

2162

goto end;

2706

2163

}

2712

2169

/* Create the Avahi service browser */

2713

2170

sb = avahi_s_service_browser_new(mc.server, if_index,

2714

2171

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2715

NULL, 0, browse_callback,

2716

(void *)&mc);

2172

NULL, 0, browse_callback, NULL);

2717

2173

if(sb == NULL){

2718

2174

fprintf_plus(stderr, "Failed to create service browser: %s\n",

2719

2175

avahi_strerror(avahi_server_errno(mc.server)));

2730

2186

if(debug){

2731

2187

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

2732

2188

}

2733

2734

ret = avahi_loop_with_timeout(simple_poll,

2735

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

2189

2190

ret = avahi_loop_with_timeout(mc.simple_poll,

2191

(int)(retry_interval * 1000));

2736

2192

if(debug){

2737

2193

fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",

2738

2194

(ret == 0) ? "successfully" : "with error");

2745

2201

}

2746

2202

2747

2203

/* Cleanup things */

2748

free(mc.interfaces);

2749

2750

2204

if(sb != NULL)

2751

2205

avahi_s_service_browser_free(sb);

2752

2206

2753

2207

if(mc.server != NULL)

2754

2208

avahi_server_free(mc.server);

2755

2209

2756

if(simple_poll != NULL)

2757

avahi_simple_poll_free(simple_poll);

2210

if(mc.simple_poll != NULL)

2211

avahi_simple_poll_free(mc.simple_poll);

2758

2212

2759

2213

if(gnutls_initialized){

2760

2214

gnutls_certificate_free_credentials(mc.cred);

2772

2226

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

2773

2227

while(mc.current_server != NULL){

2774

2228

server *next = mc.current_server->next;

2775

#ifdef __GNUC__

2776

#pragma GCC diagnostic push

2777

#pragma GCC diagnostic ignored "-Wcast-qual"

2778

#endif

2779

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

2780

#ifdef __GNUC__

2781

#pragma GCC diagnostic pop

2782

#endif

2783

2229

free(mc.current_server);

2784

2230

mc.current_server = next;

2785

2231

}

2786

2232

}

2787

2233

2788

/* Re-raise privileges */

2234

/* Run network hooks */

2235

run_network_hooks("stop", interface, delay);

2236

2237

/* Re-raise priviliges */

2789

2238

{

2790

ret_errno = raise_privileges();

2791

if(ret_errno != 0){

2792

errno = ret_errno;

2793

perror_plus("Failed to raise privileges");

2794

} else {

2795

2796

/* Run network hooks */

2797

run_network_hooks("stop", interfaces_hooks != NULL ?

2798

interfaces_hooks : "", delay);

2799

2800

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

2801

{

2802

char *interface = NULL;

2803

while((interface=argz_next(interfaces_to_take_down,

2804

interfaces_to_take_down_size,

2805

interface))){

2806

ret_errno = take_down_interface(interface);

2807

if(ret_errno != 0){

2808

errno = ret_errno;

2809

perror_plus("Failed to take down interface");

2810

}

2811

}

2812

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

2813

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

2814

" down\n");

2815

}

2816

}

2239

errno = 0;

2240

ret = seteuid(0);

2241

if(ret == -1){

2242

perror_plus("seteuid");

2817

2243

}

2818

2244

2819

ret_errno = lower_privileges_permanently();

2820

if(ret_errno != 0){

2821

errno = ret_errno;

2822

perror_plus("Failed to lower privileges permanently");

2245

/* Take down the network interface */

2246

if(take_down_interface and geteuid() == 0){

2247

ret = ioctl(sd, SIOCGIFFLAGS, &network);

2248

if(ret == -1){

2249

perror_plus("ioctl SIOCGIFFLAGS");

2250

} else if(network.ifr_flags & IFF_UP){

2251

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

2252

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

2253

if(ret == -1){

2254

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2255

}

2256

}

2257

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

2258

if(ret == -1){

2259

perror_plus("close");

2260

}

2823

2261

}

2824

2262

}

2825

2826

free(interfaces_to_take_down);

2827

free(interfaces_hooks);

2263

/* Lower privileges permanently */

2264

errno = 0;

2265

ret = setuid(uid);

2266

if(ret == -1){

2267

perror_plus("setuid");

2268

}

2828

2269

2829

2270

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

2830

if(tempdir != NULL){

2271

if(tempdir_created){

2831

2272

struct dirent **direntries = NULL;

2832

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

2833

| O_NOFOLLOW

2834

| O_DIRECTORY

2835

| O_PATH));

2836

if(tempdir_fd == -1){

2837

perror_plus("open");

2838

} else {

2839

#ifdef __GLIBC__

2840

#if __GLIBC_PREREQ(2, 15)

2841

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

2842

notdotentries, alphasort);

2843

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

2844

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

2845

alphasort);

2846

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

2847

#else /* not __GLIBC__ */

2848

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

2849

alphasort);

2850

#endif /* not __GLIBC__ */

2851

if(numentries >= 0){

2852

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

2853

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

2854

if(ret == -1){

2855

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

2856

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

2857

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

2858

}

2859

free(direntries[i]);

2860

}

2861

2862

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

2863

free(direntries);

2864

if(numentries == -1){

2865

perror_plus("scandir");

2866

}

2867

ret = rmdir(tempdir);

2868

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

2869

perror_plus("rmdir");

2870

}

2273

struct dirent *direntry = NULL;

2274

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

2275

alphasort);

2276

if (numentries > 0){

2277

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

2278

direntry = direntries[i];

2279

char *fullname = NULL;

2280

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

2281

direntry->d_name);

2282

if(ret < 0){

2283

perror_plus("asprintf");

2284

continue;

2285

}

2286

ret = remove(fullname);

2287

if(ret == -1){

2288

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

2289

strerror(errno));

2290

}

2291

free(fullname);

2871

2292

}

2872

TEMP_FAILURE_RETRY(close(tempdir_fd));

2293

}

2294

2295

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

2296

free(direntries);

2297

if (numentries == -1){

2298

perror_plus("scandir");

2299

}

2300

ret = rmdir(tempdir);

2301

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

2302

perror_plus("rmdir");

2873

2303

}

2874

2304

}

2875

2305