/mandos/release : revision 237.7.307

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() */

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42

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

43

stdout, ferror(), remove() */

44

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

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(),

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() */

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

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inet_pton(), connect(),

59

getnameinfo() */

60

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

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61

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

61

62

*/

62

63

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

63

64

strtoimax() */

64

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

65

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

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program_invocation_short_name */

67

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

73

*/

74

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

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

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

77

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

76

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

77

unlinkat() */

78

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

78

79

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

79

80

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

80

81

argp_state, struct argp,

88

89

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

89

90

WEXITSTATUS(), WTERMSIG() */

90

91

#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() */

91

98

92

99

#ifdef __linux__

93

100

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

135

142

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

136

143

char *connect_to = NULL;

137

144

const char *hookdir = HOOKDIR;

145

int hookdir_fd = -1;

146

uid_t uid = 65534;

147

gid_t gid = 65534;

138

148

139

149

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

140

150

typedef struct server{

141

151

const char *ip;

142

uint16_t port;

152

in_port_t port;

143

153

AvahiIfIndex if_index;

144

154

int af;

145

155

struct timespec last_seen;

149

159

150

160

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

151

161

typedef struct {

152

AvahiSimplePoll *simple_poll;

153

162

AvahiServer *server;

154

163

gnutls_certificate_credentials_t cred;

155

164

unsigned int dh_bits;

157

166

const char *priority;

158

167

gpgme_ctx_t ctx;

159

168

server *current_server;

169

char *interfaces;

170

size_t interfaces_size;

160

171

} mandos_context;

161

172

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 };

173

/* global so signal handler can reach it*/

174

AvahiSimplePoll *simple_poll;

167

175

168

176

sig_atomic_t quit_now = 0;

169

177

int signal_received = 0;

177

185

perror(print_text);

178

186

}

179

187

180

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

188

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

181

189

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

182

190

va_list ap;

183

191

va_start (ap, format);

184

192

185

193

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

186

194

program_invocation_short_name));

187

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

195

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

188

196

}

189

197

190

198

/*

192

200

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

193

201

* "buffer_length" is how much is already used.

194

202

*/

203

__attribute__((nonnull, warn_unused_result))

195

204

size_t incbuffer(char **buffer, size_t buffer_length,

196

205

size_t buffer_capacity){

197

206

if(buffer_length + BUFFER_SIZE > buffer_capacity){

198

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

199

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;

200

213

return 0;

201

214

}

215

*buffer = new_buf;

202

216

buffer_capacity += BUFFER_SIZE;

203

217

}

204

218

return buffer_capacity;

205

219

}

206

220

207

221

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

208

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

209

int af){

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){

210

225

int ret;

211

226

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

212

227

if(new_server == NULL){

219

234

.af = af };

220

235

if(new_server->ip == NULL){

221

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);

222

252

return false;

223

253

}

224

254

/* Special case of first server */

225

if (mc.current_server == NULL){

255

if(*current_server == NULL){

226

256

new_server->next = new_server;

227

257

new_server->prev = new_server;

228

mc.current_server = new_server;

229

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

258

*current_server = new_server;

230

259

} else {

231

new_server->next = mc.current_server;

232

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

260

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

261

new_server->next = *current_server;

262

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

233

263

new_server->prev->next = 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;

264

(*current_server)->prev = new_server;

240

265

}

241

266

return true;

242

267

}

244

269

/*

245

270

* Initialize GPGME.

246

271

*/

247

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

248

const char *tempdir){

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){

249

277

gpgme_error_t rc;

250

278

gpgme_engine_info_t engine_info;

251

279

252

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;

271

298

return false;

272

299

}

273

300

274

rc = gpgme_op_import(mc.ctx, pgp_data);

301

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

275

302

if(rc != GPG_ERR_NO_ERROR){

276

303

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

277

304

gpgme_strsource(rc), gpgme_strerror(rc));

321

348

}

322

349

323

350

/* Create new GPGME "context" */

324

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

351

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

325

352

if(rc != GPG_ERR_NO_ERROR){

326

353

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

327

354

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

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

char **plaintext){

373

char **plaintext,

374

mandos_context *mc){

346

375

gpgme_data_t dh_crypto, dh_plain;

347

376

gpgme_error_t rc;

348

377

ssize_t ret;

374

403

375

404

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

376

405

data buffer */

377

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

406

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

378

407

if(rc != GPG_ERR_NO_ERROR){

379

408

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

380

409

gpgme_strsource(rc), gpgme_strerror(rc));

381

410

plaintext_length = -1;

382

411

if(debug){

383

412

gpgme_decrypt_result_t result;

384

result = gpgme_op_decrypt_result(mc.ctx);

413

result = gpgme_op_decrypt_result(mc->ctx);

385

414

if(result == NULL){

386

415

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

387

416

} else {

464

493

return plaintext_length;

465

494

}

466

495

467

static const char * safer_gnutls_strerror(int value){

468

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

469

-Wunreachable-code */

470

if(ret == NULL)

471

ret = "(unknown)";

472

return ret;

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){

505

const char *ret = gnutls_strerror(value);

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

const char *seckeyfilename){

518

const char *seckeyfilename,

519

mandos_context *mc){

483

520

int ret;

521

unsigned int uret;

484

522

485

523

if(debug){

486

524

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

502

540

}

503

541

504

542

/* OpenPGP credentials */

505

ret = gnutls_certificate_allocate_credentials(&mc.cred);

543

ret = gnutls_certificate_allocate_credentials(&mc->cred);

506

544

if(ret != GNUTLS_E_SUCCESS){

507

545

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

508

546

safer_gnutls_strerror(ret));

518

556

}

519

557

520

558

ret = gnutls_certificate_set_openpgp_key_file

521

(mc.cred, pubkeyfilename, seckeyfilename,

559

(mc->cred, pubkeyfilename, seckeyfilename,

522

560

GNUTLS_OPENPGP_FMT_BASE64);

523

561

if(ret != GNUTLS_E_SUCCESS){

524

562

fprintf_plus(stderr,

530

568

}

531

569

532

570

/* GnuTLS server initialization */

533

ret = gnutls_dh_params_init(&mc.dh_params);

571

ret = gnutls_dh_params_init(&mc->dh_params);

534

572

if(ret != GNUTLS_E_SUCCESS){

535

573

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

536

574

" initialization: %s\n",

537

575

safer_gnutls_strerror(ret));

538

576

goto globalfail;

539

577

}

540

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

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

}

679

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

541

680

if(ret != GNUTLS_E_SUCCESS){

542

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

543

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));

544

683

goto globalfail;

545

684

}

546

685

547

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

686

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

548

687

549

688

return 0;

550

689

551

690

globalfail:

552

691

553

gnutls_certificate_free_credentials(mc.cred);

692

gnutls_certificate_free_credentials(mc->cred);

554

693

gnutls_global_deinit();

555

gnutls_dh_params_deinit(mc.dh_params);

694

gnutls_dh_params_deinit(mc->dh_params);

556

695

return -1;

557

696

}

558

697

559

static int init_gnutls_session(gnutls_session_t *session){

698

__attribute__((nonnull, warn_unused_result))

699

static int init_gnutls_session(gnutls_session_t *session,

700

mandos_context *mc){

560

701

int ret;

561

702

/* GnuTLS session creation */

562

703

do {

574

715

{

575

716

const char *err;

576

717

do {

577

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

718

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

578

719

if(quit_now){

579

720

gnutls_deinit(*session);

580

721

return -1;

591

732

592

733

do {

593

734

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

594

mc.cred);

735

mc->cred);

595

736

if(quit_now){

596

737

gnutls_deinit(*session);

597

738

return -1;

607

748

/* ignore client certificate if any. */

608

749

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

609

750

610

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

751

gnutls_dh_set_prime_bits(*session, mc->dh_bits);

611

752

612

753

return 0;

613

754

}

616

757

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

617

758

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

618

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

619

977

/* Called when a Mandos server is found */

620

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

978

__attribute__((nonnull, warn_unused_result))

979

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

621

980

AvahiIfIndex if_index,

622

int af){

981

int af, mandos_context *mc){

623

982

int ret, tcp_sd = -1;

624

983

ssize_t sret;

625

union {

626

struct sockaddr_in in;

627

struct sockaddr_in6 in6;

628

} to;

984

struct sockaddr_storage to;

629

985

char *buffer = NULL;

630

986

char *decrypted_buffer = NULL;

631

987

size_t buffer_length = 0;

634

990

int retval = -1;

635

991

gnutls_session_t session;

636

992

int pf; /* Protocol family */

993

bool route_added = false;

637

994

638

995

errno = 0;

639

996

655

1012

return -1;

656

1013

}

657

1014

658

ret = init_gnutls_session(&session);

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

1047

ret = init_gnutls_session(&session, mc);

659

1048

if(ret != 0){

660

1049

return -1;

661

1050

}

662

1051

663

1052

if(debug){

664

1053

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

665

PRIu16 "\n", ip, port);

1054

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

666

1055

}

667

1056

668

tcp_sd = socket(pf, SOCK_STREAM, 0);

1057

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

669

1058

if(tcp_sd < 0){

670

1059

int e = errno;

671

1060

perror_plus("socket");

680

1069

681

1070

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

682

1071

if(af == AF_INET6){

683

to.in6.sin6_family = (sa_family_t)af;

684

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);

685

1074

} else { /* IPv4 */

686

to.in.sin_family = (sa_family_t)af;

687

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);

688

1077

}

689

1078

if(ret < 0 ){

690

1079

int e = errno;

699

1088

goto mandos_end;

700

1089

}

701

1090

if(af == AF_INET6){

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*/

1091

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

1092

if(IN6_IS_ADDR_LINKLOCAL

1093

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

709

1094

if(if_index == AVAHI_IF_UNSPEC){

710

1095

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

711

1096

" incomplete without a network interface\n");

713

1098

goto mandos_end;

714

1099

}

715

1100

/* Set the network interface number as scope */

716

to.in6.sin6_scope_id = (uint32_t)if_index;

1101

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

717

1102

}

718

1103

} else {

719

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

720

-Wconversion and

721

-Wunreachable-code */

1104

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

722

1105

}

723

1106

724

1107

if(quit_now){

732

1115

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

733

1116

perror_plus("if_indextoname");

734

1117

} else {

735

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

736

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

1118

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

1119

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

737

1120

}

738

1121

} else {

739

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

740

ip, port);

1122

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

1123

ip, (uintmax_t)port);

741

1124

}

742

1125

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

743

1126

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

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;

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;

783

1207

}

784

1208

785

1209

const char *out = mandos_protocol_version;

821

1245

goto mandos_end;

822

1246

}

823

1247

824

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

825

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1248

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

1249

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

1250

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

1251

gnutls_transport_set_ptr(session,

1252

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

826

1253

827

1254

if(quit_now){

828

1255

errno = EINTR;

933

1360

if(buffer_length > 0){

934

1361

ssize_t decrypted_buffer_size;

935

1362

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

936

&decrypted_buffer);

1363

&decrypted_buffer, mc);

937

1364

if(decrypted_buffer_size >= 0){

938

1365

939

1366

written = 0;

965

1392

966

1393

mandos_end:

967

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

}

968

1401

int e = errno;

969

1402

free(decrypted_buffer);

970

1403

free(buffer);

987

1420

return retval;

988

1421

}

989

1422

1423

__attribute__((nonnull))

990

1424

static void resolve_callback(AvahiSServiceResolver *r,

991

1425

AvahiIfIndex interface,

992

1426

AvahiProtocol proto,

1000

1434

AVAHI_GCC_UNUSED AvahiStringList *txt,

1001

1435

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1002

1436

flags,

1003

AVAHI_GCC_UNUSED void* userdata){

1004

assert(r);

1437

void *mc){

1438

if(r == NULL){

1439

return;

1440

}

1005

1441

1006

1442

/* Called whenever a service has been resolved successfully or

1007

1443

timed out */

1008

1444

1009

1445

if(quit_now){

1446

avahi_s_service_resolver_free(r);

1010

1447

return;

1011

1448

}

1012

1449

1016

1453

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

1017

1454

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

1018

1455

domain,

1019

avahi_strerror(avahi_server_errno(mc.server)));

1456

avahi_strerror(avahi_server_errno

1457

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

1020

1458

break;

1021

1459

1022

1460

case AVAHI_RESOLVER_FOUND:

1028

1466

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

1029

1467

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

1030

1468

}

1031

int ret = start_mandos_communication(ip, port, interface,

1032

avahi_proto_to_af(proto));

1469

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

1470

interface,

1471

avahi_proto_to_af(proto),

1472

mc);

1033

1473

if(ret == 0){

1034

avahi_simple_poll_quit(mc.simple_poll);

1474

avahi_simple_poll_quit(simple_poll);

1035

1475

} else {

1036

if(not add_server(ip, port, interface,

1037

avahi_proto_to_af(proto))){

1476

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

1477

avahi_proto_to_af(proto),

1478

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

1038

1479

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

1039

1480

" list\n", name);

1040

1481

}

1053

1494

const char *domain,

1054

1495

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1055

1496

flags,

1056

AVAHI_GCC_UNUSED void* userdata){

1057

assert(b);

1497

void *mc){

1498

if(b == NULL){

1499

return;

1500

}

1058

1501

1059

1502

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

1060

1503

is removed from the LAN */

1068

1511

case AVAHI_BROWSER_FAILURE:

1069

1512

1070

1513

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

1071

avahi_strerror(avahi_server_errno(mc.server)));

1072

avahi_simple_poll_quit(mc.simple_poll);

1514

avahi_strerror(avahi_server_errno

1515

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

1516

avahi_simple_poll_quit(simple_poll);

1073

1517

return;

1074

1518

1075

1519

case AVAHI_BROWSER_NEW:

1078

1522

the callback function is called the Avahi server will free the

1079

1523

resolver for us. */

1080

1524

1081

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

1082

name, type, domain, protocol, 0,

1083

resolve_callback, NULL) == NULL)

1525

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

1526

interface, protocol, name, type,

1527

domain, protocol, 0,

1528

resolve_callback, mc) == NULL)

1084

1529

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

1085

1530

" %s\n", name,

1086

avahi_strerror(avahi_server_errno(mc.server)));

1531

avahi_strerror(avahi_server_errno

1532

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

1087

1533

break;

1088

1534

1089

1535

case AVAHI_BROWSER_REMOVE:

1108

1554

signal_received = sig;

1109

1555

int old_errno = errno;

1110

1556

/* set main loop to exit */

1111

if(mc.simple_poll != NULL){

1112

avahi_simple_poll_quit(mc.simple_poll);

1557

if(simple_poll != NULL){

1558

avahi_simple_poll_quit(simple_poll);

1113

1559

}

1114

1560

errno = old_errno;

1115

1561

}

1116

1562

1563

__attribute__((nonnull, warn_unused_result))

1117

1564

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

1118

1565

int ret;

1566

error_t ret_errno;

1119

1567

1120

1568

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

1121

1569

if(s < 0){

1570

ret_errno = errno;

1122

1571

perror_plus("socket");

1572

errno = ret_errno;

1123

1573

return false;

1124

1574

}

1125

1575

strcpy(ifr->ifr_name, ifname);

1126

1576

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1127

1577

if(ret == -1){

1128

1578

if(debug){

1579

ret_errno = errno;

1129

1580

perror_plus("ioctl SIOCGIFFLAGS");

1581

errno = ret_errno;

1130

1582

}

1131

1583

return false;

1132

1584

}

1133

1585

return true;

1134

1586

}

1135

1587

1588

__attribute__((nonnull, warn_unused_result))

1136

1589

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

1137

1590

1138

1591

/* Reject the loopback device */

1180

1633

* corresponds to an acceptable network device.

1181

1634

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

1182

1635

*/

1636

__attribute__((nonnull, warn_unused_result))

1183

1637

int good_interface(const struct dirent *if_entry){

1184

1638

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

1185

1639

return 0;

1201

1655

}

1202

1656

1203

1657

/*

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

1658

* This function determines if a network interface is up.

1659

*/

1660

__attribute__((nonnull, warn_unused_result))

1661

bool interface_is_up(const char *interface){

1662

struct ifreq ifr;

1663

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

1664

if(debug){

1665

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

1666

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

1667

}

1668

return false;

1669

}

1670

1671

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

1672

}

1673

1674

/*

1675

* This function determines if a network interface is running

1676

*/

1677

__attribute__((nonnull, warn_unused_result))

1678

bool interface_is_running(const char *interface){

1679

struct ifreq ifr;

1680

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

1681

if(debug){

1682

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

1683

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

1684

}

1685

return false;

1686

}

1687

1688

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

1689

}

1690

1691

__attribute__((nonnull, pure, warn_unused_result))

1246

1692

int notdotentries(const struct dirent *direntry){

1247

1693

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

1248

1694

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

1255

1701

}

1256

1702

1257

1703

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

1704

__attribute__((nonnull, warn_unused_result))

1258

1705

int runnable_hook(const struct dirent *direntry){

1259

1706

int ret;

1260

1707

size_t sret;

1268

1715

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

1269

1716

"abcdefghijklmnopqrstuvwxyz"

1270

1717

"0123456789"

1271

"_-");

1718

"_.-");

1272

1719

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

1273

1720

/* Contains non-allowed characters */

1274

1721

if(debug){

1278

1725

return 0;

1279

1726

}

1280

1727

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);

1728

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

1289

1729

if(ret == -1){

1290

1730

if(debug){

1291

1731

perror_plus("Could not stat hook");

1315

1755

return 1;

1316

1756

}

1317

1757

1318

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1758

__attribute__((nonnull, warn_unused_result))

1759

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1760

mandos_context *mc){

1319

1761

int ret;

1320

1762

struct timespec now;

1321

1763

struct timespec waited_time;

1322

1764

intmax_t block_time;

1323

1765

1324

1766

while(true){

1325

if(mc.current_server == NULL){

1326

if (debug){

1767

if(mc->current_server == NULL){

1768

if(debug){

1327

1769

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

1328

1770

" No timeout!\n");

1329

1771

}

1330

1772

ret = avahi_simple_poll_iterate(s, -1);

1331

1773

} else {

1332

if (debug){

1774

if(debug){

1333

1775

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

1334

1776

" it, or wait\n");

1335

1777

}

1342

1784

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

1343

1785

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

1344

1786

waited_time.tv_sec = (now.tv_sec

1345

- mc.current_server->last_seen.tv_sec);

1787

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

1346

1788

waited_time.tv_nsec = (now.tv_nsec

1347

- mc.current_server->last_seen.tv_nsec);

1789

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

1348

1790

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

1349

1791

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

1350

1792

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

1352

1794

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

1353

1795

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

1354

1796

1355

if (debug){

1797

if(debug){

1356

1798

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

1357

1799

block_time);

1358

1800

}

1359

1801

1360

1802

if(block_time <= 0){

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);

1803

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

1804

mc->current_server->port,

1805

mc->current_server->if_index,

1806

mc->current_server->af, mc);

1365

1807

if(ret == 0){

1366

avahi_simple_poll_quit(mc.simple_poll);

1808

avahi_simple_poll_quit(s);

1367

1809

return 0;

1368

1810

}

1369

1811

ret = clock_gettime(CLOCK_MONOTONIC,

1370

&mc.current_server->last_seen);

1812

&mc->current_server->last_seen);

1371

1813

if(ret == -1){

1372

1814

perror_plus("clock_gettime");

1373

1815

return -1;

1374

1816

}

1375

mc.current_server = mc.current_server->next;

1817

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

1376

1818

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

1377

1819

servers, but don't block */

1378

1820

}

1380

1822

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

1381

1823

}

1382

1824

if(ret != 0){

1383

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

1825

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

1384

1826

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

1385

1827

}

1386

1828

}

1387

1829

}

1388

1830

}

1389

1831

1390

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

1832

__attribute__((nonnull))

1833

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

1391

1834

const float delay){

1392

struct dirent **direntries;

1393

struct dirent *direntry;

1394

int ret;

1395

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

1396

alphasort);

1835

struct dirent **direntries = NULL;

1836

if(hookdir_fd == -1){

1837

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1838

| O_CLOEXEC);

1839

if(hookdir_fd == -1){

1840

if(errno == ENOENT){

1841

if(debug){

1842

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

1843

" found\n", hookdir);

1844

}

1845

} else {

1846

perror_plus("open");

1847

}

1848

return;

1849

}

1850

}

1851

#ifdef __GLIBC__

1852

#if __GLIBC_PREREQ(2, 15)

1853

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

1854

runnable_hook, alphasort);

1855

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

1856

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

1857

alphasort);

1858

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

1859

#else /* not __GLIBC__ */

1860

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

1861

alphasort);

1862

#endif /* not __GLIBC__ */

1397

1863

if(numhooks == -1){

1398

1864

perror_plus("scandir");

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){

1865

return;

1866

}

1867

struct dirent *direntry;

1868

int ret;

1869

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

1870

if(devnull == -1){

1871

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

1872

return;

1873

}

1874

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

1875

direntry = direntries[i];

1876

if(debug){

1877

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

1878

direntry->d_name);

1879

}

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){

1406

1926

perror_plus("asprintf");

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("VERBOSITY", 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

}

1927

_exit(EX_OSERR);

1928

}

1929

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

1930

if(ret == -1){

1475

1931

free(delaystring);

1476

if(connect_to != NULL){

1477

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

1478

if(ret == -1){

1479

perror_plus("setenv");

1480

_exit(EX_OSERR);

1481

}

1482

}

1483

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

1484

perror_plus("execl");

1485

_exit(EXIT_FAILURE);

1486

}

1487

} else {

1488

int status;

1489

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

1490

perror_plus("waitpid");

1491

free(fullname);

1492

continue;

1493

}

1494

if(WIFEXITED(status)){

1495

if(WEXITSTATUS(status) != 0){

1496

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

1497

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

1498

WEXITSTATUS(status));

1499

free(fullname);

1500

continue;

1501

}

1502

} else if(WIFSIGNALED(status)){

1503

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

1504

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

1505

WTERMSIG(status));

1506

free(fullname);

1507

continue;

1508

} else {

1509

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

1510

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

1511

free(fullname);

1512

continue;

1513

}

1514

}

1515

free(fullname);

1516

if(debug){

1517

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

1518

direntry->d_name);

1519

}

1520

}

1521

close(devnull);

1522

}

1523

return true;

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;

2000

} else {

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);

2020

}

2021

2022

__attribute__((nonnull, warn_unused_result))

2023

error_t bring_up_interface(const char *const interface,

2024

const float delay){

2025

error_t old_errno = errno;

2026

int ret;

2027

struct ifreq network;

2028

unsigned int if_index = if_nametoindex(interface);

2029

if(if_index == 0){

2030

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

2031

errno = old_errno;

2032

return ENXIO;

2033

}

2034

2035

if(quit_now){

2036

errno = old_errno;

2037

return EINTR;

2038

}

2039

2040

if(not interface_is_up(interface)){

2041

error_t ret_errno = 0, ioctl_errno = 0;

2042

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

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 |= IFF_UP; /* set 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(quit_now){

2060

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

2061

if(ret == -1){

2062

perror_plus("close");

2063

}

2064

errno = old_errno;

2065

return EINTR;

2066

}

2067

2068

if(debug){

2069

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

2070

interface);

2071

}

2072

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

}

2079

2080

#ifdef __linux__

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

}

2092

}

2093

#endif /* __linux__ */

2094

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

2095

ioctl_errno = errno;

2096

#ifdef __linux__

2097

if(restore_loglevel){

2098

ret_linux = klogctl(7, NULL, 0);

2099

if(ret_linux == -1){

2100

perror_plus("klogctl");

2101

}

2102

}

2103

#endif /* __linux__ */

2104

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

}

2114

2115

/* Close the socket */

2116

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

2117

if(ret == -1){

2118

perror_plus("close");

2119

}

2120

2121

if(ret_setflags == -1){

2122

errno = ioctl_errno;

2123

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2124

errno = old_errno;

2125

return ioctl_errno;

2126

}

2127

} else if(debug){

2128

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

2129

interface);

2130

}

2131

2132

/* Sleep checking until interface is running.

2133

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

2134

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

2135

if(interface_is_running(interface)){

2136

break;

2137

}

2138

struct timespec sleeptime = { .tv_nsec = 250000000 };

2139

ret = nanosleep(&sleeptime, NULL);

2140

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

2141

perror_plus("nanosleep");

2142

}

2143

}

2144

2145

errno = old_errno;

2146

return 0;

2147

}

2148

2149

__attribute__((nonnull, warn_unused_result))

2150

error_t take_down_interface(const char *const interface){

2151

error_t old_errno = errno;

2152

struct ifreq network;

2153

unsigned int if_index = if_nametoindex(interface);

2154

if(if_index == 0){

2155

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

2156

errno = old_errno;

2157

return ENXIO;

2158

}

2159

if(interface_is_up(interface)){

2160

error_t ret_errno = 0, ioctl_errno = 0;

2161

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

2162

ret_errno = errno;

2163

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

2164

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

2165

errno = old_errno;

2166

return ret_errno;

2167

}

2168

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

2169

2170

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

2171

if(sd == -1){

2172

ret_errno = errno;

2173

perror_plus("socket");

2174

errno = old_errno;

2175

return ret_errno;

2176

}

2177

2178

if(debug){

2179

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

2180

interface);

2181

}

2182

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

}

2202

2203

/* Close the socket */

2204

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

2205

if(ret == -1){

2206

perror_plus("close");

2207

}

2208

2209

if(ret_setflags == -1){

2210

errno = ioctl_errno;

2211

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2212

errno = old_errno;

2213

return ioctl_errno;

2214

}

2215

} else if(debug){

2216

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

2217

interface);

2218

}

2219

2220

errno = old_errno;

2221

return 0;

1524

2222

}

1525

2223

1526

2224

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

2225

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

2226

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

2227

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

2228

.interfaces = NULL, .interfaces_size = 0 };

1527

2229

AvahiSServiceBrowser *sb = NULL;

1528

int error;

2230

error_t ret_errno;

1529

2231

int ret;

1530

2232

intmax_t tmpmax;

1531

2233

char *tmp;

1532

2234

int exitcode = EXIT_SUCCESS;

1533

const char *interface = "";

1534

struct ifreq network;

1535

int sd = -1;

1536

bool take_down_interface = false;

1537

uid_t uid;

1538

gid_t gid;

1539

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

1540

bool tempdir_created = false;

2235

char *interfaces_to_take_down = NULL;

2236

size_t interfaces_to_take_down_size = 0;

2237

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

2238

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

2239

char *tempdir = NULL;

1541

2240

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1542

2241

const char *seckey = PATHDIR "/" SECKEY;

1543

2242

const char *pubkey = PATHDIR "/" PUBKEY;

2243

char *interfaces_hooks = NULL;

1544

2244

1545

2245

bool gnutls_initialized = false;

1546

2246

bool gpgme_initialized = false;

1637

2337

connect_to = arg;

1638

2338

break;

1639

2339

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

1640

interface = arg;

2340

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

2341

arg, (int)',');

2342

if(ret_errno != 0){

2343

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

2344

}

1641

2345

break;

1642

2346

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

1643

2347

seckey = arg;

1715

2419

goto end;

1716

2420

}

1717

2421

}

1718

2422

1719

2423

{

1720

2424

/* Work around Debian bug #633582:

1721

2425

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

1722

2426

1723

/* Re-raise priviliges */

1724

errno = 0;

1725

ret = seteuid(0);

1726

if(ret == -1){

1727

perror_plus("seteuid");

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");

1728

2432

} else {

1729

2433

struct stat st;

1730

2434

1748

2452

TEMP_FAILURE_RETRY(close(seckey_fd));

1749

2453

}

1750

2454

}

1751

2455

1752

2456

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

1753

2457

int pubkey_fd = open(pubkey, O_RDONLY);

1754

2458

if(pubkey_fd == -1){

1769

2473

TEMP_FAILURE_RETRY(close(pubkey_fd));

1770

2474

}

1771

2475

}

1772

2476

1773

2477

/* Lower privileges */

1774

errno = 0;

1775

ret = seteuid(uid);

1776

if(ret == -1){

1777

perror_plus("seteuid");

2478

ret_errno = lower_privileges();

2479

if(ret_errno != 0){

2480

errno = ret_errno;

2481

perror_plus("Failed to lower privileges");

2482

}

2483

}

2484

}

2485

2486

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

2487

{

2488

char *interface = NULL;

2489

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

2490

interface))){

2491

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

2492

and if_nametoindex(interface) == 0){

2493

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

2494

fprintf_plus(stderr, "Not using nonexisting interface"

2495

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

2496

}

2497

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

2498

interface = NULL;

1778

2499

}

1779

2500

}

1780

2501

}

1781

2502

1782

2503

/* Run network hooks */

1783

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

1784

goto end;

2504

{

2505

if(mc.interfaces != NULL){

2506

interfaces_hooks = malloc(mc.interfaces_size);

2507

if(interfaces_hooks == NULL){

2508

perror_plus("malloc");

2509

goto end;

2510

}

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);

1785

2516

}

1786

2517

1787

2518

if(not debug){

1788

2519

avahi_set_log_function(empty_log);

1789

2520

}

1790

2521

1791

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

1792

struct dirent **direntries;

1793

/* First look for interfaces that are up */

1794

ret = scandir(sys_class_net, &direntries, up_interface,

1795

alphasort);

1796

if(ret == 0){

1797

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

1798

free(direntries);

1799

ret = scandir(sys_class_net, &direntries, good_interface,

1800

alphasort);

1801

}

1802

if(ret >= 1){

1803

/* Pick the first interface returned */

1804

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

1805

if(debug){

1806

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

1807

}

1808

if(interface == NULL){

1809

perror_plus("malloc");

1810

free(direntries);

1811

exitcode = EXIT_FAILURE;

1812

goto end;

1813

}

1814

free(direntries);

1815

} else {

1816

free(direntries);

1817

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

1818

exitcode = EXIT_FAILURE;

1819

goto end;

1820

}

1821

}

1822

1823

2522

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

1824

2523

from the signal handler */

1825

2524

/* Initialize the pseudo-RNG for Avahi */

1826

2525

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

1827

mc.simple_poll = avahi_simple_poll_new();

1828

if(mc.simple_poll == NULL){

2526

simple_poll = avahi_simple_poll_new();

2527

if(simple_poll == NULL){

1829

2528

fprintf_plus(stderr,

1830

2529

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

1831

2530

exitcode = EX_UNAVAILABLE;

1895

2594

}

1896

2595

}

1897

2596

1898

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

1899

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

1900

if_index = (AvahiIfIndex) if_nametoindex(interface);

1901

if(if_index == 0){

1902

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

1903

exitcode = EX_UNAVAILABLE;

1904

goto end;

1905

}

1906

1907

if(quit_now){

1908

goto end;

1909

}

1910

1911

/* Re-raise priviliges */

1912

errno = 0;

1913

ret = seteuid(0);

1914

if(ret == -1){

1915

perror_plus("seteuid");

1916

}

1917

1918

#ifdef __linux__

1919

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1920

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

1921

ret = klogctl(8, NULL, 5);

1922

bool restore_loglevel = true;

1923

if(ret == -1){

1924

restore_loglevel = false;

1925

perror_plus("klogctl");

1926

}

1927

#endif /* __linux__ */

1928

1929

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1930

if(sd < 0){

1931

perror_plus("socket");

1932

exitcode = EX_OSERR;

1933

#ifdef __linux__

1934

if(restore_loglevel){

1935

ret = klogctl(7, NULL, 0);

1936

if(ret == -1){

1937

perror_plus("klogctl");

1938

}

1939

}

1940

#endif /* __linux__ */

1941

/* Lower privileges */

1942

errno = 0;

1943

ret = seteuid(uid);

1944

if(ret == -1){

1945

perror_plus("seteuid");

1946

}

1947

goto end;

1948

}

1949

strcpy(network.ifr_name, interface);

1950

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

1951

if(ret == -1){

1952

perror_plus("ioctl SIOCGIFFLAGS");

1953

#ifdef __linux__

1954

if(restore_loglevel){

1955

ret = klogctl(7, NULL, 0);

1956

if(ret == -1){

1957

perror_plus("klogctl");

1958

}

1959

}

1960

#endif /* __linux__ */

1961

exitcode = EX_OSERR;

1962

/* Lower privileges */

1963

errno = 0;

1964

ret = seteuid(uid);

1965

if(ret == -1){

1966

perror_plus("seteuid");

1967

}

1968

goto end;

1969

}

1970

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

1971

network.ifr_flags |= IFF_UP;

1972

take_down_interface = true;

1973

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

1974

if(ret == -1){

1975

take_down_interface = false;

1976

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1977

exitcode = EX_OSERR;

1978

#ifdef __linux__

1979

if(restore_loglevel){

1980

ret = klogctl(7, NULL, 0);

1981

if(ret == -1){

1982

perror_plus("klogctl");

2597

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

2598

if(mc.interfaces == NULL){

2599

struct dirent **direntries = NULL;

2600

/* Look for any good interfaces */

2601

ret = scandir(sys_class_net, &direntries, good_interface,

2602

alphasort);

2603

if(ret >= 1){

2604

/* Add all found interfaces to interfaces list */

2605

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

2606

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

2607

direntries[i]->d_name);

2608

if(ret_errno != 0){

2609

errno = ret_errno;

2610

perror_plus("argz_add");

2611

free(direntries[i]);

2612

continue;

2613

}

2614

if(debug){

2615

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

2616

direntries[i]->d_name);

2617

}

2618

free(direntries[i]);

2619

}

2620

free(direntries);

2621

} else {

2622

if(ret == 0){

2623

free(direntries);

2624

}

2625

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

2626

exitcode = EXIT_FAILURE;

2627

goto end;

2628

}

2629

}

2630

2631

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

2632

{

2633

char *interface = NULL;

2634

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

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;

1983

2648

}

1984

2649

}

1985

#endif /* __linux__ */

1986

/* Lower privileges */

1987

errno = 0;

1988

ret = seteuid(uid);

1989

if(ret == -1){

1990

perror_plus("seteuid");

1991

}

1992

goto end;

1993

}

1994

}

1995

/* Sleep checking until interface is running.

1996

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

1997

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

1998

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

1999

if(ret == -1){

2000

perror_plus("ioctl SIOCGIFFLAGS");

2001

} else if(network.ifr_flags & IFF_RUNNING){

2002

2650

break;

2003

2651

}

2004

struct timespec sleeptime = { .tv_nsec = 250000000 };

2005

ret = nanosleep(&sleeptime, NULL);

2006

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

2007

perror_plus("nanosleep");

2008

}

2009

}

2010

if(not take_down_interface){

2011

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

2012

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

2013

if(ret == -1){

2014

perror_plus("close");

2015

}

2016

}

2017

#ifdef __linux__

2018

if(restore_loglevel){

2019

/* Restores kernel loglevel to default */

2020

ret = klogctl(7, NULL, 0);

2021

if(ret == -1){

2022

perror_plus("klogctl");

2023

}

2024

}

2025

#endif /* __linux__ */

2026

/* Lower privileges */

2027

errno = 0;

2028

/* Lower privileges */

2029

ret = seteuid(uid);

2030

if(ret == -1){

2031

perror_plus("seteuid");

2032

}

2652

bool interface_was_up = interface_is_up(interface);

2653

errno = bring_up_interface(interface, delay);

2654

if(not interface_was_up){

2655

if(errno != 0){

2656

perror_plus("Failed to bring up interface");

2657

} else {

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

}

2664

}

2665

}

2666

}

2667

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

2668

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

2669

}

2670

}

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);

2033

2679

}

2034

2680

2035

2681

if(quit_now){

2036

2682

goto end;

2037

2683

}

2038

2684

2039

ret = init_gnutls_global(pubkey, seckey);

2685

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

2040

2686

if(ret == -1){

2041

2687

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

2042

2688

exitcode = EX_UNAVAILABLE;

2049

2695

goto end;

2050

2696

}

2051

2697

2052

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){

2053

2708

perror_plus("mkdtemp");

2054

2709

goto end;

2055

2710

}

2056

tempdir_created = true;

2057

2711

2058

2712

if(quit_now){

2059

2713

goto end;

2060

2714

}

2061

2715

2062

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

2716

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

2063

2717

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

2064

2718

exitcode = EX_UNAVAILABLE;

2065

2719

goto end;

2075

2729

/* Connect directly, do not use Zeroconf */

2076

2730

/* (Mainly meant for debugging) */

2077

2731

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

2732

2078

2733

if(address == NULL){

2079

2734

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

2080

2735

exitcode = EX_USAGE;

2085

2740

goto end;

2086

2741

}

2087

2742

2088

uint16_t port;

2743

in_port_t port;

2089

2744

errno = 0;

2090

2745

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

2091

2746

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

2092

or tmpmax != (uint16_t)tmpmax){

2747

or tmpmax != (in_port_t)tmpmax){

2093

2748

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

2094

2749

exitcode = EX_USAGE;

2095

2750

goto end;

2096

2751

}

2097

2752

2098

2753

if(quit_now){

2099

2754

goto end;

2100

2755

}

2101

2756

2102

port = (uint16_t)tmpmax;

2757

port = (in_port_t)tmpmax;

2103

2758

*address = '\0';

2104

2759

/* Colon in address indicates IPv6 */

2105

2760

int af;

2121

2776

}

2122

2777

2123

2778

while(not quit_now){

2124

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

2779

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

2780

&mc);

2125

2781

if(quit_now or ret == 0){

2126

2782

break;

2127

2783

}

2129

2785

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

2130

2786

(int)retry_interval);

2131

2787

}

2132

sleep((int)retry_interval);

2788

sleep((unsigned int)retry_interval);

2133

2789

}

2134

2790

2135

if (not quit_now){

2791

if(not quit_now){

2136

2792

exitcode = EXIT_SUCCESS;

2137

2793

}

2138

2794

2153

2809

config.publish_domain = 0;

2154

2810

2155

2811

/* Allocate a new server */

2156

mc.server = avahi_server_new(avahi_simple_poll_get

2157

(mc.simple_poll), &config, NULL,

2158

NULL, &error);

2812

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2813

&config, NULL, NULL, &ret_errno);

2159

2814

2160

2815

/* Free the Avahi configuration data */

2161

2816

avahi_server_config_free(&config);

2164

2819

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

2165

2820

if(mc.server == NULL){

2166

2821

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

2167

avahi_strerror(error));

2822

avahi_strerror(ret_errno));

2168

2823

exitcode = EX_UNAVAILABLE;

2169

2824

goto end;

2170

2825

}

2176

2831

/* Create the Avahi service browser */

2177

2832

sb = avahi_s_service_browser_new(mc.server, if_index,

2178

2833

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2179

NULL, 0, browse_callback, NULL);

2834

NULL, 0, browse_callback,

2835

(void *)&mc);

2180

2836

if(sb == NULL){

2181

2837

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

2182

2838

avahi_strerror(avahi_server_errno(mc.server)));

2193

2849

if(debug){

2194

2850

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

2195

2851

}

2196

2197

ret = avahi_loop_with_timeout(mc.simple_poll,

2198

(int)(retry_interval * 1000));

2852

2853

ret = avahi_loop_with_timeout(simple_poll,

2854

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

2199

2855

if(debug){

2200

2856

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

2201

2857

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

2208

2864

}

2209

2865

2210

2866

/* Cleanup things */

2867

free(mc.interfaces);

2868

2211

2869

if(sb != NULL)

2212

2870

avahi_s_service_browser_free(sb);

2213

2871

2214

2872

if(mc.server != NULL)

2215

2873

avahi_server_free(mc.server);

2216

2874

2217

if(mc.simple_poll != NULL)

2218

avahi_simple_poll_free(mc.simple_poll);

2875

if(simple_poll != NULL)

2876

avahi_simple_poll_free(simple_poll);

2219

2877

2220

2878

if(gnutls_initialized){

2221

2879

gnutls_certificate_free_credentials(mc.cred);

2233

2891

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

2234

2892

while(mc.current_server != NULL){

2235

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

2236

2902

free(mc.current_server);

2237

2903

mc.current_server = next;

2238

2904

}

2239

2905

}

2240

2906

2241

/* Run network hooks */

2242

run_network_hooks("stop", interface, delay);

2243

2244

/* Re-raise priviliges */

2907

/* Re-raise privileges */

2245

2908

{

2246

errno = 0;

2247

ret = seteuid(0);

2248

if(ret == -1){

2249

perror_plus("seteuid");

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

}

2250

2936

}

2251

2937

2252

/* Take down the network interface */

2253

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

2254

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

2255

if(ret == -1){

2256

perror_plus("ioctl SIOCGIFFLAGS");

2257

} else if(network.ifr_flags & IFF_UP){

2258

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

2259

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

2260

if(ret == -1){

2261

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2262

}

2263

}

2264

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

2265

if(ret == -1){

2266

perror_plus("close");

2267

}

2938

ret_errno = lower_privileges_permanently();

2939

if(ret_errno != 0){

2940

errno = ret_errno;

2941

perror_plus("Failed to lower privileges permanently");

2268

2942

}

2269

2943

}

2270

/* Lower privileges permanently */

2271

errno = 0;

2272

ret = setuid(uid);

2273

if(ret == -1){

2274

perror_plus("setuid");

2275

}

2944

2945

free(interfaces_to_take_down);

2946

free(interfaces_hooks);

2276

2947

2277

2948

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

2278

if(tempdir_created){

2949

if(tempdir != NULL){

2279

2950

struct dirent **direntries = NULL;

2280

struct dirent *direntry = NULL;

2281

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

2282

alphasort);

2283

if (numentries > 0){

2284

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

2285

direntry = direntries[i];

2286

char *fullname = NULL;

2287

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

2288

direntry->d_name);

2289

if(ret < 0){

2290

perror_plus("asprintf");

2291

continue;

2292

}

2293

ret = remove(fullname);

2294

if(ret == -1){

2295

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

2296

strerror(errno));

2297

}

2298

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

}

2299

2990

}

2300

}

2301

2302

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

2303

free(direntries);

2304

if (numentries == -1){

2305

perror_plus("scandir");

2306

}

2307

ret = rmdir(tempdir);

2308

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

2309

perror_plus("rmdir");

2991

TEMP_FAILURE_RETRY(close(tempdir_fd));

2310

2992

}

2311

2993

}

2312

2994